CA1334839C - Slant plate type compressor with variable displacement mechanism - Google Patents
Slant plate type compressor with variable displacement mechanismInfo
- Publication number
- CA1334839C CA1334839C CA000584103A CA584103A CA1334839C CA 1334839 C CA1334839 C CA 1334839C CA 000584103 A CA000584103 A CA 000584103A CA 584103 A CA584103 A CA 584103A CA 1334839 C CA1334839 C CA 1334839C
- Authority
- CA
- Canada
- Prior art keywords
- valve
- plate
- pressure
- pistons
- compressor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B25/00—Multi-stage pumps
- F04B25/04—Multi-stage pumps having cylinders coaxial with, or parallel or inclined to, main shaft axis
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
- F04B2027/1809—Controlled pressure
- F04B2027/1813—Crankcase pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
- F04B2027/1822—Valve-controlled fluid connection
- F04B2027/1831—Valve-controlled fluid connection between crankcase and suction chamber
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
- F04B2027/184—Valve controlling parameter
- F04B2027/185—Discharge pressure
Abstract
A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylin-ders and is reciprocated by a drive mechanism which includes a mem-ber having a surface with an adjustable incline angle. The incline angle is controlled by the pressure situation in the crank chamber.
The pressure in crank chamber is controlled by control mechanism which comprises a passageway communicating between the crank chamber and a suction chamber and valve device to control the clos-ing and opening of the passageway. The valve device includes a valve element which directly controls the closing and opening of passage-way. A valve device includes a bellows valve element and a valve shifting element. The valve shifting element is coupled to the bellows to apply a force to the bellows and thereby shift a control point of the bellows in response changes in the discharge chamber pressure.
The pressure in crank chamber is controlled by control mechanism which comprises a passageway communicating between the crank chamber and a suction chamber and valve device to control the clos-ing and opening of the passageway. The valve device includes a valve element which directly controls the closing and opening of passage-way. A valve device includes a bellows valve element and a valve shifting element. The valve shifting element is coupled to the bellows to apply a force to the bellows and thereby shift a control point of the bellows in response changes in the discharge chamber pressure.
Description
~ 334839 VARIABLE DISPLACEMENT SLANT PLATE COMPRESSOR
SENSITIVE TO SUCTION AND DISCHARGE PRESSURE CONTROL
BACKGROUND OF THE INVENTION
Teçhni~l Field The present invention relates to a refrigerant compressor, and more particularly, to a slant plate type compressor, such as a wobble plate type compressor, with a variable displacement mech~ni~m suit-able for use in an automotive air conditioning system.
Description Of The Prior Art It has been recognized that it is desirable to provide a slant plate type piston compressor with a displacement or capacity adjust-ing mech~ni~m to control the compression ratio in response to dem~n-l. As disclosed in U.S. Patent No. 4,428,718, the compression ratio may be controlled by changing the slant angle of the sloping surface of a slant plate in response to the operation of a valve control mech~niem. The slant angle of the slant plate is adjusted to maintain a constant suction pressure in response to a change in the heat load of the evap~orator of an external circuit inclu~ling the compressor or a change in rotation speed of the compressor.
In an air conditioning system, a pipe member connects the out-let of an evaporator to the suction ch~mher of the compressor.
Accordingly, a pressure loss occurs between the suction chamber and the outlet of the evaporator which is directly proportional to the ~suction flow rate" therebetween . As a result when the capacity of the compressor is adjusted to maintain a con-stant suction ch~mber pressure in response to appropriate changes in the heat load of the evaporator or the rotation speed of the compres-sor, the pressure at the evaporator outlet increases. This increase in A
SENSITIVE TO SUCTION AND DISCHARGE PRESSURE CONTROL
BACKGROUND OF THE INVENTION
Teçhni~l Field The present invention relates to a refrigerant compressor, and more particularly, to a slant plate type compressor, such as a wobble plate type compressor, with a variable displacement mech~ni~m suit-able for use in an automotive air conditioning system.
Description Of The Prior Art It has been recognized that it is desirable to provide a slant plate type piston compressor with a displacement or capacity adjust-ing mech~ni~m to control the compression ratio in response to dem~n-l. As disclosed in U.S. Patent No. 4,428,718, the compression ratio may be controlled by changing the slant angle of the sloping surface of a slant plate in response to the operation of a valve control mech~niem. The slant angle of the slant plate is adjusted to maintain a constant suction pressure in response to a change in the heat load of the evap~orator of an external circuit inclu~ling the compressor or a change in rotation speed of the compressor.
In an air conditioning system, a pipe member connects the out-let of an evaporator to the suction ch~mher of the compressor.
Accordingly, a pressure loss occurs between the suction chamber and the outlet of the evaporator which is directly proportional to the ~suction flow rate" therebetween . As a result when the capacity of the compressor is adjusted to maintain a con-stant suction ch~mber pressure in response to appropriate changes in the heat load of the evaporator or the rotation speed of the compres-sor, the pressure at the evaporator outlet increases. This increase in A
- 2 - l 33483q the evaporator outlet pressure results in an undesirable decrease in the heat exchange ability of the evaporator.
Above mentioned U.S. Patent No. ~,428,~18 discloses a valve control mech~nicm~ to eliminate this problem. The valve control merh~nicm, which is responsive to both suction and discharge pres-sures, provides controlled communication of both suction and dis-charge fluid with the compres-cor crank ch~mber and thereby controls compressor displacement. The compressor control point for displace-ment change is shifted to maintain a nearly constant pressure at the evaporator outlet portion by means of this compressor displacement control. The valve control mech~nicm makes use of the fact that the discharge pressure of the compressor is roughly directly proportional to the suction flow rate.
However, in the above-mentioned valve control mech~nism, a single movable valve memher, formed of a number of parts, is used to control the flow of fluid both between the discharge ch~mher and the crankcase chAmber, and between the crankcase ch~mher and the suc-tion rh~mher. Thus, extreme precision is required in the formation of each part and in the ~ccemhly of the large numher of parts into the control merh~ni~cm in order to assure that the valve control mecha-nism operates properly. Furthermore, when the heat load of the evaporator or the rotation speed of the compressor is changed quickly, discharge ch~mber pressure increases and an exces~i~e amount of dicch~rge gas flows into the crank ~h~mher from the dis-charge rh~mhpr through a communication passage of the valve con-trol mech~nicm due to a lag time between the operation of the valve control merh~nicm and the responce of the external circuit inclurlinc the compressor. As a result of the exces-sive amount of ~icch~rge gas flow, a decrease in compression effi-ciency of the compressor, and a derRne of durability of the compres-sor internal parts, occurs.
The variable displacement control merh~nicm in a slant plate type of compre_sor, in accordance with the present invention, was developed to take advantage of the relationship between discharge pressure and suction flow rate in a m~nner which overcomes the A
1 33483~
_ - 3 disadvantages of a prior art mechanism such as disclosed in the '718 patent. That is, the control mechanism of the present invention was designed to have a simple physical structure and to operate in a direct manner on a valve controlling element in response to discharge pressure changes, thereby resolving the complexity, excessive discharge flow and slow response time problems.
The '718 patent discloses a capacity adjusting mechanism used in a wobble plate type compressor. As is typical in this type of compressor, the wobble plate is disposed at a slant or incline angle relative to the drive axis, nutates but does not rotate, and drivingly couples the pistons to the drive source. This type of capacity adjusting mechanism, using selective fluid communication between the crank chamber and the suction chamber, however, can be used in any type of compressor which uses a slanted plate or surface in the drive mechanism. For example, U.S.
Patent No. 4,664,604, issued to Terauchi, discloses this type of capacity adjusting mechanism in a swash plate type compressor. The swash plate, like the wobble plate, is disposed at a slant angle and drivingly couples the pistons to the drive source. However, while the wobble plate only nutates, the swash plate both nutates and rotates. The term slant piate type compressor will therefore be used therein to refer to any type of compressor, including wobble and swash plate types, which use a slanted plate or surface in the drive mechanism.
~UMMARY OF THE INVENTION
It is an object of an aspect of this invention to provide a slant plate type piston compressor having a capacity adjusting mechanism which compensates for the increase in pressure at the evaporator outlet when the capacity of the compressor is adjusted, to maintain a constant evaporator outlet pressure with the control mechanism having a simple structure and operating in a direct and responsive manner.
Various aspects of this invention are as follows:
_ 4 In a slant plate type refrigerant compressor including a compressor housing having a central portion, a front end plate at one end and a rear end plate at its other end, said housing having a cylinder block provided with a plurality of cylinders and a crank chamber adjacent said cylinder block, a piston slidably fitted within each of the said cylinders, a drive mechanism coupled to said pistons to reciprocate said pistons within said cylinders, said drive mechanism including a drive shaft rotatably supported in said housing, a rotor coupled to said drive shaft and rotatable therewith, and coupling means for drivingly coupling said rotor to said pistons such that the rotary motion of said rotor is converted into reciprocating motion of said pistons, said coupling means including a member having a surface disposed at an incline angle relative to said drive shaft, said incline angle of said member being adjustable to vary the stroke length of said pistons and the capacity of the compressor, said rear end plate having a suction chamber and a discharge chamber, a passageway connected between said crank chamber and said suction chamber, and valve control means for controlling the closing and opening of said passageway to vary the capacity of the compressor by adjusting the incline angle, the improvement comprising:
said valve control means including a valve element opening and closing said passageway and a valve shifting element coupled to said valve element by an elastic element to apply a force to said valve element and shift a control point of said valve element in response to changes in discharge pressure.
In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected ! A
- 4a -to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means comprising a longitudinally expanding and contracting bellows and a valve member attached at one end of said bellows to open and close said passageway, a cylinder member having a first end adjacent to said valve member, and an actuating rod slidably disposed within said cylinder member and receiving the discharge pressure at one end so as to longitudinally move and thereby apply a force to and move said valve member to shift the control point of said bellows in response to changes in discharge pressure.
In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said ~ ,, A.
- 4b -crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means including a valve element primarily responsive to pressure in said suction chamber and opening said passageway when the pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the suction pressure response point of said valve element with increasing discharge pressure.
In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement r~ .
- 4c _ 1 3 3 4 8 39 comprising:
said valve control means including a valve element primarily responsive to pressure in said crank chamber and opening said passageway when the crank chamber pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the crank chamber pressure response point of said valve element with increasing discharge pressure.
Further objects, features and other aspects of the invention will be understood from the detailed description of the preferred embodiments of this invention with reference to the drawings.
Figure 1 is a vertical longitudinal sectional view of a wobble plate type refrigerant compressor in accordance with a first embodiment of this invention.
Figure 2 is an enlarged partially sectional view of a valve control mechanism shown in Figure 1.
Figure 3 is a vertical longitudinal sectional view of a wobble plate type refrigerant compressor in accordance with a second embodiment of this invention.
Figure 4 is a vertical longitudinal sectional view of a wobble plate type refrigerant compressor in accordance with a third embodiment of this invention.
s 1 334839 Figure 5 is a graph showing the relationship between the pres-sure loss occurring between the evaporator outlet portion and the compressor suction ch~mher and the suction flow rate.
DETAILED DESCRIPTION OF THE pREF~l~R~r~ EMBODIMENTS
With reference to Figure 1, the construction of a slant plate type compressor, specifically a wobble plate type refrigerant com-pressor 10 in accordance with one emboliment of the present inven-tion is shown. Compressor 10 includes cylindrical housing ~ccemhly 20 incllJ~ling cylinder block 21, front end plate 23 at one end of cylinder block 21, crank ch~mher 22 formed between cylinder block 21 and front end plate 23, and rear end plate 24 attached to the other end of cylinder block 21. Front end plate 23 is mounted on cylinder block 21 forward (to the left in Figure 1) of crank ch~mher 22 by a plurality of bolts 101. Rear end plate 24 is mounted on cylinder block 21 at is opposite end by a plurality of bolts 102. Valve plate 25 is located between rear end plate 24 and cylinder block 21. Opening 231 is cen-trally formed in front end plate 23 for supporting drive shaft 26 by bearing 30 dicp~sed in the opening. The inner end portion of drive shaft 26 i,s rotatably supported by bearing 31 disposed within central bore 210 of cylinder block 21. Bore 210 extends to a rearward end surface of cylinder block 21 to ~ ~se valve control mech~nicm 19 as discu~sed below.
Cam rotor 40 is fixed on drive shaft 26 by pin member 261 and rotates with shaft 26. Thrust needle bearing 32 is ~i.cp~sed between the inner end surface of front end plate 23 and the adjacent axial end surface of cam rotor 40. Cam rotor 40 includes arm 41 having pin memher 42 extending therefrom. Slant plate 50 is adjacent cam rotor 40 and includes opening 53 through which passes drive shaft 26. Slant plate 50 includes arm 51 having slot 52. Cam rotor 40 and slant plate 50 are connected by pin memher 42, which is inserted in slot 52 to create a hinged joint. Pin member 42 is sli~l~hle within slot 52 to allow adjustment of the angular position of slant plate 50 with respect to the longitudinal axis of drive shaft 26.
Wobble plate 60 is rotatably mounted on slant plate 50 through bearings 61 and 62. Fork shaped slider 63 is attached to the outer - -6- l 33483~
peripheral end of wobble plate 60 and is slidably mounted on sliding rail 64 held between front end plate 23 and cylinder block 21. Fork shaped slider 63 prevents rotation of wobble plate 60 and wobble plate 60 nutates along rail 64 when cam rotor 40 rotates. Cylinder block 21 includes a plurality of peripherally located cylinder ch~mbers 70 in which pistons ~1 reciprocate. Each piston 71 is connected to wobble plate 60 by a corresponding connecting rod 72.
Rear end plate 24 includes peripherally located ~nn~ r suction ch~mber 241 and centrally located discharge ch~mber 251. Valve plate 25 is located between cylinder block 21 and rear end plate 24 and includes a plurality of valved suction ports 242 linking suction ~h~mher 241 with respective cylinders ~0. Valve plate 25 also includes a plurality of valved discharge ports 252 linking discharge ~h~mberS 251 with respective cylinders ~0. Suction ports 242 and discharge ports 252 are provided with suitable reed valves as described in U.S. Patent No. 4,011,029 to Shimi7lu Suction r~h~mher 241 includes inlet portion 241a which is con-nected to an evaporator of the external cooling circuit (not shown).
Discharge chamher 251 is provided with outlet portion 251a connected to a condencer of the cooling circuit (not shown). Gaskets 2~ and 28 are located between cylinder block 21 and the inner surface of valve plate 25, and the outer surface of valve plate 25 and rear end plate 24 respectively, to seal the mating surfaces of cylinder block 21, valve plate 25 and rear end plate 24.
With reference to Figure 2, additionally, valve control mecha-nism 19 includes cup-shaped casing member 191 defining valve cham-ber 192 therewithin. O-ring 19a is disposed between an outer surface of casing member 191 and an inner surface of bore 210 to seal the mating surfaces of casing member 191 and cylinder block 21. A plu-rality of holes 19b are formed at a closed end (to the left in Figures 1 and 2) of casing member 191 to lead crank ch~mher pressure into valve ch~mber 192 through a gap 31a existing between bearing 31 and cylinder block 21. Bellows 193 is ~licp~ced in valve ch~mber 192 to longitudinally contract and expand in response to crank chamber pressure. Projection member 193b attached at forward (to the left in 7 1 33483q Figures 1 and 2) end of bellows 193 is secured to axial projection 19c formed at a center of closed end of casing member 191. Valve mem-ber 193a is attached at rearward (to the right in Figures 1 and 2) end of bellows 193.
Cylinder memher 194 including valve seat 194a penetrates a center of valve plate ~.c~embly 200 which includes valve plate 25, gaskets 27, 28, suction valve member 271 and discharge valve member 281. Valve seat 194a is formed at forward end of cylinder member 194 and is secured to an opened end of casing memher 191. Nuts 100 are screwed on cylinder member 194 from a rearward end of cylinder member 194 located in discharge ch~mber 251 to fix cylinder member 194 to valve plate ~Ccem~h~ly 200 with valve retainer 253. Conical shaped opening 194b receiving valve member 193a is formed at valve seat 194a and is linked to cylinder 194c axially formed in cylinder member 194. Actuating rod 195 is slidably ~ p~sed within cylinder 194c, slightly projects from the rearward end of cylinder 194c, and is linked to valve member 193a through bias spring 196. O-ring 197 is disposed between an inner surface of cylinder 194c and an outer sur-face of actuating rod 195 to seal the mating surfaces of cylinder 194c and actuating rod 195.
Radial hole 151 is formed at valve seat 194a to link conical shaped opening 194b to one end opening of conduit 152 formed at cyl-inder block 21. Conduit 152 inçludPs cavity 152a and also links to suction ch~mher 242 through hole 153 formed at valve plate ~csembly 200. Pas~age~.ay 150, which provides communication between crank ~h~mher 22 and suction ch~mber 241, is obtained by uniting gap 31a, bore 210, holes 19b, valve ~h~mher 192, conical shaped opening 194b, radial hole lSl, conduit 152 and hole 153.
In result, the opening and closing of passageway 150 is con-trolled by the contracting and ~xp~n~ling of bellows 193 in response to crank ch~mber pressure.
During operation of compressor 10, drive shaft 26 is rotated by the engine of the vehicle through an electromagnetic clutch 300.
Cam rotor 40 is rotated with drive shaft 26, rotating slant plate 50 as well, which causes wobble plate 60 to nutate. Nutational motion of -8- l 3348~9 wobble plate 60 reciprocates pistons 71 in their respective cylinders 70. As pistons 71 are reciprocated, refrigerant gas which is intro-duced into suction ch~mber 241 through inlet portion 241a, flows into each cylinder 70 through suction ports 242 and then compressed. The compressed refrigerant gas is discharged to discharge ch~mber 251 from each cylinder 70 through discharge ports 252, and therefrom into the cooling circuit through outlet portion 251a.
The capacity of compressor 10 is adjusted to maintain a con-stant pressure in suction ch~mber 241 in rP-cpol-~e to a change in the heat load of the evaporator or a change in the rotating speed of the compr~sor. The capacity of the compressor is adjusted by ch~nging the angle of the slant plate which is dependent upon the crank cham-ber pressure. An increase in crank ch~mh~r pressure decreases the slant angle of the slant plate and thus the wobble plate, decreasing the capacity of the compr~sor. A decrease in the crank ch~mber pressure increases the angle of the slant plate and the wobble plate and thus increases the capacity of the compressor.
The effect of the valve control mech~ni~m of the present invention is to maintain a constant pressure at the outlet of the evap-orator during capacity control of the compressor in the following m~nner. Actuating rod 195 pushes valve membelr 192 in the direction to contract bellows 193 through bias spring 196, which smoothly transmits the force from actuating rod 195 to valve member 193a of bellows 193. Actuating rod 195 is moved in r~onse to receiving dis-charge pressure in discharge ch~mher 251. Accordingly, increasing discharge pressure in discharge ch~mher 251 further moves rod 195 toward bellows 193, thereby increasing tendency to contract bellows 193. As a result, the compressor control point for displacement change is shifted to maintain a constant pressure at the evaporator outlet portion. That is, the valve control merh~ni~m makes use of the fact that the discharge pressure of the compressor is roughly directly proporlional to the suction flow rate. Since actuating rod 195 moves in direct response to changes in discharge pressure and applies a force directly to bellows 193 (the controlling valve element), the control g point at which bellows 193 operates is shifted in a very direct and responsive m~nnpr by changes in discharge pressure.
Figure 3 shows a second embodiment of the present invention in which the same numerals are used to denote the same elements shown in Figures 1 and 2. In the second embodiment, cavity 220 dis-posing valve control me~h~nicm 19 is formed at a central portion of cylinder block 21 and is isolated from bore 210 which rotatably sup-ports drive shaft 26. Holes 19b link valve ch~mher 192 to space 221 provided at the forward end of cavity 220. Conduit 162, linking space 221 to suction ch~mber 242 through hole 153, is formed in cylinder block 21 to lead suction ch~mhPr pressure into space 221. Conduit 163, linking crank ~h~mber 22 to radial hole 151, is also formed in cylinder block 21. P~ geway 160 c~ nicating crank chamber 22 and suction chamber 242 i~ thus obtained by uniting conduit 163, radial hole 151, conical shaped opening 194b, valve ch~mher 192, holes 19b, space 221, conduit 162 and hole 153. In result, the opening and closing of pa~a~e~ay 160 is controlled by the contracting and ~p~ntling of bellows 193 in rea~ollse to suction ch~mh~er pressure.
Figure 4 shows a third emho~liment of the present invention in which the same numerals are used to denote the same elements shown in Figures 1 and 2. In the third emhoAiment the cavity, in which the valve control mech~ni~m is dicp~se~l, is formed in the cylinder block at a location radially offset from the axis of the drive shaft. That is, cavity 230, receiving the valve control me~h~nicm, is formed in cylin-der block 21 at a location radially offset from an axis of drive shaft 26. Conduit 171 is formed in cylinder block 21 to lead crank ch~mber pressure into valve ch~mher 192 via holes 19b.
The operation of the valve control mech~ni~mc of the second and third embo~impnts are substantially similar to that in the firct embodiment and a further ~xpl~nation of these operations are omitted.
This invention has been described in connection with the pre-ferred emho~liments. These emho~liments, however, are merely for example only and the invention is not restricted thereto. It will be understood by those skilled in the art that other variations and A
-lo- I 334839 modifications can easily be made within the scope of this invention as defined by the claims.
Above mentioned U.S. Patent No. ~,428,~18 discloses a valve control mech~nicm~ to eliminate this problem. The valve control merh~nicm, which is responsive to both suction and discharge pres-sures, provides controlled communication of both suction and dis-charge fluid with the compres-cor crank ch~mber and thereby controls compressor displacement. The compressor control point for displace-ment change is shifted to maintain a nearly constant pressure at the evaporator outlet portion by means of this compressor displacement control. The valve control mech~nicm makes use of the fact that the discharge pressure of the compressor is roughly directly proportional to the suction flow rate.
However, in the above-mentioned valve control mech~nism, a single movable valve memher, formed of a number of parts, is used to control the flow of fluid both between the discharge ch~mher and the crankcase chAmber, and between the crankcase ch~mher and the suc-tion rh~mher. Thus, extreme precision is required in the formation of each part and in the ~ccemhly of the large numher of parts into the control merh~ni~cm in order to assure that the valve control mecha-nism operates properly. Furthermore, when the heat load of the evaporator or the rotation speed of the compressor is changed quickly, discharge ch~mber pressure increases and an exces~i~e amount of dicch~rge gas flows into the crank ~h~mher from the dis-charge rh~mhpr through a communication passage of the valve con-trol mech~nicm due to a lag time between the operation of the valve control merh~nicm and the responce of the external circuit inclurlinc the compressor. As a result of the exces-sive amount of ~icch~rge gas flow, a decrease in compression effi-ciency of the compressor, and a derRne of durability of the compres-sor internal parts, occurs.
The variable displacement control merh~nicm in a slant plate type of compre_sor, in accordance with the present invention, was developed to take advantage of the relationship between discharge pressure and suction flow rate in a m~nner which overcomes the A
1 33483~
_ - 3 disadvantages of a prior art mechanism such as disclosed in the '718 patent. That is, the control mechanism of the present invention was designed to have a simple physical structure and to operate in a direct manner on a valve controlling element in response to discharge pressure changes, thereby resolving the complexity, excessive discharge flow and slow response time problems.
The '718 patent discloses a capacity adjusting mechanism used in a wobble plate type compressor. As is typical in this type of compressor, the wobble plate is disposed at a slant or incline angle relative to the drive axis, nutates but does not rotate, and drivingly couples the pistons to the drive source. This type of capacity adjusting mechanism, using selective fluid communication between the crank chamber and the suction chamber, however, can be used in any type of compressor which uses a slanted plate or surface in the drive mechanism. For example, U.S.
Patent No. 4,664,604, issued to Terauchi, discloses this type of capacity adjusting mechanism in a swash plate type compressor. The swash plate, like the wobble plate, is disposed at a slant angle and drivingly couples the pistons to the drive source. However, while the wobble plate only nutates, the swash plate both nutates and rotates. The term slant piate type compressor will therefore be used therein to refer to any type of compressor, including wobble and swash plate types, which use a slanted plate or surface in the drive mechanism.
~UMMARY OF THE INVENTION
It is an object of an aspect of this invention to provide a slant plate type piston compressor having a capacity adjusting mechanism which compensates for the increase in pressure at the evaporator outlet when the capacity of the compressor is adjusted, to maintain a constant evaporator outlet pressure with the control mechanism having a simple structure and operating in a direct and responsive manner.
Various aspects of this invention are as follows:
_ 4 In a slant plate type refrigerant compressor including a compressor housing having a central portion, a front end plate at one end and a rear end plate at its other end, said housing having a cylinder block provided with a plurality of cylinders and a crank chamber adjacent said cylinder block, a piston slidably fitted within each of the said cylinders, a drive mechanism coupled to said pistons to reciprocate said pistons within said cylinders, said drive mechanism including a drive shaft rotatably supported in said housing, a rotor coupled to said drive shaft and rotatable therewith, and coupling means for drivingly coupling said rotor to said pistons such that the rotary motion of said rotor is converted into reciprocating motion of said pistons, said coupling means including a member having a surface disposed at an incline angle relative to said drive shaft, said incline angle of said member being adjustable to vary the stroke length of said pistons and the capacity of the compressor, said rear end plate having a suction chamber and a discharge chamber, a passageway connected between said crank chamber and said suction chamber, and valve control means for controlling the closing and opening of said passageway to vary the capacity of the compressor by adjusting the incline angle, the improvement comprising:
said valve control means including a valve element opening and closing said passageway and a valve shifting element coupled to said valve element by an elastic element to apply a force to said valve element and shift a control point of said valve element in response to changes in discharge pressure.
In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected ! A
- 4a -to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means comprising a longitudinally expanding and contracting bellows and a valve member attached at one end of said bellows to open and close said passageway, a cylinder member having a first end adjacent to said valve member, and an actuating rod slidably disposed within said cylinder member and receiving the discharge pressure at one end so as to longitudinally move and thereby apply a force to and move said valve member to shift the control point of said bellows in response to changes in discharge pressure.
In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said ~ ,, A.
- 4b -crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means including a valve element primarily responsive to pressure in said suction chamber and opening said passageway when the pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the suction pressure response point of said valve element with increasing discharge pressure.
In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement r~ .
- 4c _ 1 3 3 4 8 39 comprising:
said valve control means including a valve element primarily responsive to pressure in said crank chamber and opening said passageway when the crank chamber pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the crank chamber pressure response point of said valve element with increasing discharge pressure.
Further objects, features and other aspects of the invention will be understood from the detailed description of the preferred embodiments of this invention with reference to the drawings.
Figure 1 is a vertical longitudinal sectional view of a wobble plate type refrigerant compressor in accordance with a first embodiment of this invention.
Figure 2 is an enlarged partially sectional view of a valve control mechanism shown in Figure 1.
Figure 3 is a vertical longitudinal sectional view of a wobble plate type refrigerant compressor in accordance with a second embodiment of this invention.
Figure 4 is a vertical longitudinal sectional view of a wobble plate type refrigerant compressor in accordance with a third embodiment of this invention.
s 1 334839 Figure 5 is a graph showing the relationship between the pres-sure loss occurring between the evaporator outlet portion and the compressor suction ch~mher and the suction flow rate.
DETAILED DESCRIPTION OF THE pREF~l~R~r~ EMBODIMENTS
With reference to Figure 1, the construction of a slant plate type compressor, specifically a wobble plate type refrigerant com-pressor 10 in accordance with one emboliment of the present inven-tion is shown. Compressor 10 includes cylindrical housing ~ccemhly 20 incllJ~ling cylinder block 21, front end plate 23 at one end of cylinder block 21, crank ch~mher 22 formed between cylinder block 21 and front end plate 23, and rear end plate 24 attached to the other end of cylinder block 21. Front end plate 23 is mounted on cylinder block 21 forward (to the left in Figure 1) of crank ch~mher 22 by a plurality of bolts 101. Rear end plate 24 is mounted on cylinder block 21 at is opposite end by a plurality of bolts 102. Valve plate 25 is located between rear end plate 24 and cylinder block 21. Opening 231 is cen-trally formed in front end plate 23 for supporting drive shaft 26 by bearing 30 dicp~sed in the opening. The inner end portion of drive shaft 26 i,s rotatably supported by bearing 31 disposed within central bore 210 of cylinder block 21. Bore 210 extends to a rearward end surface of cylinder block 21 to ~ ~se valve control mech~nicm 19 as discu~sed below.
Cam rotor 40 is fixed on drive shaft 26 by pin member 261 and rotates with shaft 26. Thrust needle bearing 32 is ~i.cp~sed between the inner end surface of front end plate 23 and the adjacent axial end surface of cam rotor 40. Cam rotor 40 includes arm 41 having pin memher 42 extending therefrom. Slant plate 50 is adjacent cam rotor 40 and includes opening 53 through which passes drive shaft 26. Slant plate 50 includes arm 51 having slot 52. Cam rotor 40 and slant plate 50 are connected by pin memher 42, which is inserted in slot 52 to create a hinged joint. Pin member 42 is sli~l~hle within slot 52 to allow adjustment of the angular position of slant plate 50 with respect to the longitudinal axis of drive shaft 26.
Wobble plate 60 is rotatably mounted on slant plate 50 through bearings 61 and 62. Fork shaped slider 63 is attached to the outer - -6- l 33483~
peripheral end of wobble plate 60 and is slidably mounted on sliding rail 64 held between front end plate 23 and cylinder block 21. Fork shaped slider 63 prevents rotation of wobble plate 60 and wobble plate 60 nutates along rail 64 when cam rotor 40 rotates. Cylinder block 21 includes a plurality of peripherally located cylinder ch~mbers 70 in which pistons ~1 reciprocate. Each piston 71 is connected to wobble plate 60 by a corresponding connecting rod 72.
Rear end plate 24 includes peripherally located ~nn~ r suction ch~mber 241 and centrally located discharge ch~mber 251. Valve plate 25 is located between cylinder block 21 and rear end plate 24 and includes a plurality of valved suction ports 242 linking suction ~h~mher 241 with respective cylinders ~0. Valve plate 25 also includes a plurality of valved discharge ports 252 linking discharge ~h~mberS 251 with respective cylinders ~0. Suction ports 242 and discharge ports 252 are provided with suitable reed valves as described in U.S. Patent No. 4,011,029 to Shimi7lu Suction r~h~mher 241 includes inlet portion 241a which is con-nected to an evaporator of the external cooling circuit (not shown).
Discharge chamher 251 is provided with outlet portion 251a connected to a condencer of the cooling circuit (not shown). Gaskets 2~ and 28 are located between cylinder block 21 and the inner surface of valve plate 25, and the outer surface of valve plate 25 and rear end plate 24 respectively, to seal the mating surfaces of cylinder block 21, valve plate 25 and rear end plate 24.
With reference to Figure 2, additionally, valve control mecha-nism 19 includes cup-shaped casing member 191 defining valve cham-ber 192 therewithin. O-ring 19a is disposed between an outer surface of casing member 191 and an inner surface of bore 210 to seal the mating surfaces of casing member 191 and cylinder block 21. A plu-rality of holes 19b are formed at a closed end (to the left in Figures 1 and 2) of casing member 191 to lead crank ch~mher pressure into valve ch~mber 192 through a gap 31a existing between bearing 31 and cylinder block 21. Bellows 193 is ~licp~ced in valve ch~mber 192 to longitudinally contract and expand in response to crank chamber pressure. Projection member 193b attached at forward (to the left in 7 1 33483q Figures 1 and 2) end of bellows 193 is secured to axial projection 19c formed at a center of closed end of casing member 191. Valve mem-ber 193a is attached at rearward (to the right in Figures 1 and 2) end of bellows 193.
Cylinder memher 194 including valve seat 194a penetrates a center of valve plate ~.c~embly 200 which includes valve plate 25, gaskets 27, 28, suction valve member 271 and discharge valve member 281. Valve seat 194a is formed at forward end of cylinder member 194 and is secured to an opened end of casing memher 191. Nuts 100 are screwed on cylinder member 194 from a rearward end of cylinder member 194 located in discharge ch~mber 251 to fix cylinder member 194 to valve plate ~Ccem~h~ly 200 with valve retainer 253. Conical shaped opening 194b receiving valve member 193a is formed at valve seat 194a and is linked to cylinder 194c axially formed in cylinder member 194. Actuating rod 195 is slidably ~ p~sed within cylinder 194c, slightly projects from the rearward end of cylinder 194c, and is linked to valve member 193a through bias spring 196. O-ring 197 is disposed between an inner surface of cylinder 194c and an outer sur-face of actuating rod 195 to seal the mating surfaces of cylinder 194c and actuating rod 195.
Radial hole 151 is formed at valve seat 194a to link conical shaped opening 194b to one end opening of conduit 152 formed at cyl-inder block 21. Conduit 152 inçludPs cavity 152a and also links to suction ch~mher 242 through hole 153 formed at valve plate ~csembly 200. Pas~age~.ay 150, which provides communication between crank ~h~mher 22 and suction ch~mber 241, is obtained by uniting gap 31a, bore 210, holes 19b, valve ~h~mher 192, conical shaped opening 194b, radial hole lSl, conduit 152 and hole 153.
In result, the opening and closing of passageway 150 is con-trolled by the contracting and ~xp~n~ling of bellows 193 in response to crank ch~mber pressure.
During operation of compressor 10, drive shaft 26 is rotated by the engine of the vehicle through an electromagnetic clutch 300.
Cam rotor 40 is rotated with drive shaft 26, rotating slant plate 50 as well, which causes wobble plate 60 to nutate. Nutational motion of -8- l 3348~9 wobble plate 60 reciprocates pistons 71 in their respective cylinders 70. As pistons 71 are reciprocated, refrigerant gas which is intro-duced into suction ch~mber 241 through inlet portion 241a, flows into each cylinder 70 through suction ports 242 and then compressed. The compressed refrigerant gas is discharged to discharge ch~mber 251 from each cylinder 70 through discharge ports 252, and therefrom into the cooling circuit through outlet portion 251a.
The capacity of compressor 10 is adjusted to maintain a con-stant pressure in suction ch~mber 241 in rP-cpol-~e to a change in the heat load of the evaporator or a change in the rotating speed of the compr~sor. The capacity of the compressor is adjusted by ch~nging the angle of the slant plate which is dependent upon the crank cham-ber pressure. An increase in crank ch~mh~r pressure decreases the slant angle of the slant plate and thus the wobble plate, decreasing the capacity of the compr~sor. A decrease in the crank ch~mber pressure increases the angle of the slant plate and the wobble plate and thus increases the capacity of the compressor.
The effect of the valve control mech~ni~m of the present invention is to maintain a constant pressure at the outlet of the evap-orator during capacity control of the compressor in the following m~nner. Actuating rod 195 pushes valve membelr 192 in the direction to contract bellows 193 through bias spring 196, which smoothly transmits the force from actuating rod 195 to valve member 193a of bellows 193. Actuating rod 195 is moved in r~onse to receiving dis-charge pressure in discharge ch~mher 251. Accordingly, increasing discharge pressure in discharge ch~mher 251 further moves rod 195 toward bellows 193, thereby increasing tendency to contract bellows 193. As a result, the compressor control point for displacement change is shifted to maintain a constant pressure at the evaporator outlet portion. That is, the valve control merh~ni~m makes use of the fact that the discharge pressure of the compressor is roughly directly proporlional to the suction flow rate. Since actuating rod 195 moves in direct response to changes in discharge pressure and applies a force directly to bellows 193 (the controlling valve element), the control g point at which bellows 193 operates is shifted in a very direct and responsive m~nnpr by changes in discharge pressure.
Figure 3 shows a second embodiment of the present invention in which the same numerals are used to denote the same elements shown in Figures 1 and 2. In the second embodiment, cavity 220 dis-posing valve control me~h~nicm 19 is formed at a central portion of cylinder block 21 and is isolated from bore 210 which rotatably sup-ports drive shaft 26. Holes 19b link valve ch~mher 192 to space 221 provided at the forward end of cavity 220. Conduit 162, linking space 221 to suction ch~mber 242 through hole 153, is formed in cylinder block 21 to lead suction ch~mhPr pressure into space 221. Conduit 163, linking crank ~h~mber 22 to radial hole 151, is also formed in cylinder block 21. P~ geway 160 c~ nicating crank chamber 22 and suction chamber 242 i~ thus obtained by uniting conduit 163, radial hole 151, conical shaped opening 194b, valve ch~mher 192, holes 19b, space 221, conduit 162 and hole 153. In result, the opening and closing of pa~a~e~ay 160 is controlled by the contracting and ~p~ntling of bellows 193 in rea~ollse to suction ch~mh~er pressure.
Figure 4 shows a third emho~liment of the present invention in which the same numerals are used to denote the same elements shown in Figures 1 and 2. In the third emhoAiment the cavity, in which the valve control mech~ni~m is dicp~se~l, is formed in the cylinder block at a location radially offset from the axis of the drive shaft. That is, cavity 230, receiving the valve control me~h~nicm, is formed in cylin-der block 21 at a location radially offset from an axis of drive shaft 26. Conduit 171 is formed in cylinder block 21 to lead crank ch~mber pressure into valve ch~mher 192 via holes 19b.
The operation of the valve control mech~ni~mc of the second and third embo~impnts are substantially similar to that in the firct embodiment and a further ~xpl~nation of these operations are omitted.
This invention has been described in connection with the pre-ferred emho~liments. These emho~liments, however, are merely for example only and the invention is not restricted thereto. It will be understood by those skilled in the art that other variations and A
-lo- I 334839 modifications can easily be made within the scope of this invention as defined by the claims.
Claims (21)
1. In a slant plate type refrigerant compressor including a compressor housing having a central portion, a front end plate at one end and a rear end plate at its other end, said housing having a cylinder block provided with a plurality of cylinders and a crank chamber adjacent said cylinder block, a piston slidably fitted within each of the said cylinders, a drive mechanism coupled to said pistons to reciprocate said pistons within said cylinders, said drive mechanism including a drive shaft rotatably supported in said housing, a rotor coupled to said drive shaft and rotatable therewith, and coupling means for drivingly coupling said rotor to said pistons such that the rotary motion of said rotor is converted into reciprocating motion of said pistons, said coupling means including a member having a surface disposed at an incline angle relative to said drive shaft, said incline angle of said member being adjustable to vary the stroke length of said pistons and the capacity of the compressor, said rear end plate having a suction chamber and a discharge chamber, a passageway connected between said crank chamber and said suction chamber, and valve control means for controlling the closing and opening of said passageway to vary the capacity of the compressor by adjusting the incline angle, the improvement comprising:
said valve control means including a valve element opening and closing said passageway and a valve shifting element coupled to said valve element by an elastic element to apply a force to said valve element and shift a control point of said valve element in response to changes in discharge pressure.
said valve control means including a valve element opening and closing said passageway and a valve shifting element coupled to said valve element by an elastic element to apply a force to said valve element and shift a control point of said valve element in response to changes in discharge pressure.
2. The refrigerant compressor of claim 1 wherein said valve element comprises a longitudinally expanding and contracting bellows and a valve member attached at one end of said bellows.
3. The refrigerant compressor of claim 2 wherein said valve shifting element comprises a cylinder member and an actuating rod, said cylinder member having a first end adjacent to said valve member of said valve element and a second end, and said actuating rod being slidably disposed within said cylinder member so as to longitudinally move said valve member of said valve element in response to receiving the discharge pressure at one end surface of said actuating rod.
4. The refrigerant compressor of claim 3 wherein said second end of cylinder member is located in said discharge chamber and said one end surface of said actuating rod is disposed at said second end of said cylinder member.
5. The refrigerant compressor of claim 1 wherein said elastic means is a bias spring.
6. The refrigerant compressor of claim 1 wherein said valve control means controls the opening and closing of said passageway in response to a change in suction chamber pressure.
7. The refrigerant compressor of claim 1 wherein said valve control means controls the opening and closing of said passageway in response to a change in crank chamber pressure.
8. The refrigerant compressor of claim 1 wherein a surface of said valve shifting element is acted on by fluid in said discharge chamber.
9. The refrigerant compressor of claim 8 wherein said valve shifting element includes a rod slidable along its length, a first end of said rod coupled to said valve element and a second end having said surface acted on by fluid in said discharge chamber whereby increases in the fluid pressure in said discharge chamber slides said rod toward said valve element to have said first end of said rod apply a force to said valve element.
10. The refrigerant compressor of claim 9 wherein said second end of said rod is disposed in said discharge chamber.
11. The refrigerant compressor of claim 9 wherein said valve element includes a longitudinally expanding and contracting bellows.
12. The slant plate type refrigerant compressor recited in claim 1, said coupling means comprising a wobble plate disposed about said drive shaft, said inclined surface of said member in close proximity to said wobble plate, said wobble plate linked to said pistons, rotational motion of said member converted to nutational motion of said wobble plate to reciprocate said pistons in said cylinders.
13. In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means comprising a longitudinally expanding and contracting bellows and a valve member attached at one end of said bellows to open and close said passageway, a cylinder member having a first end adjacent to said valve member, and an actuating rod slidably disposed within said cylinder member and receiving the discharge pressure at one end so as to longitudinally move and thereby apply a force to and move said valve member to shift the control point of said bellows in response to changes in discharge pressure.
said valve control means comprising a longitudinally expanding and contracting bellows and a valve member attached at one end of said bellows to open and close said passageway, a cylinder member having a first end adjacent to said valve member, and an actuating rod slidably disposed within said cylinder member and receiving the discharge pressure at one end so as to longitudinally move and thereby apply a force to and move said valve member to shift the control point of said bellows in response to changes in discharge pressure.
14. In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means including a valve element primarily responsive to pressure in said suction chamber and opening said passageway when the pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the suction pressure response point of said valve element with increasing discharge pressure.
said valve control means including a valve element primarily responsive to pressure in said suction chamber and opening said passageway when the pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the suction pressure response point of said valve element with increasing discharge pressure.
15. The refrigerant compressor recited in claim 14, said elastic element comprising a bias spring.
16. The refrigerant compressor recited in claim 14, said valve element comprising a bellows having a valve member attached at one end thereof, said bellows longitudinally expanding or contracting in response to the suction pressure.
17. The refrigerant compressor recited in claim 14, said coupling means comprising a wobble plate disposed about said drive shaft, said inclined surface of said slant plate in close proximity to said wobble plate, said wobble plate linked to said pistons, rotational motion of said slant plate converted to nutational motion of said wobble plate to reciprocate said pistons in said cylinders.
18. In a refrigerant compressor including a compressor housing having a cylinder block provided with a plurality of cylinders, a front end plate disposed on one end of said cylinder block and enclosing a crank chamber within said cylinder block, a piston slidably fitted within each of said cylinders and reciprocated by a drive mechanism including a rotor connected to a drive shaft, an adjustable slant plate having an inclined surface adjustably connected to said rotor and having an adjustable slant angle with respect to said drive shaft, and linking means for operationally linking said slant plate to said pistons such that rotation of said drive shaft, rotor and slant plate reciprocates said pistons in said cylinders, said slant angle changing in response to a change in pressure in said crank chamber to change the capacity of said compressor, a rear end plate disposed on the opposite end of said cylinder block from said front end plate and defining a suction chamber and a discharge chamber therein, a passageway linking said suction chamber with said crank chamber and a valve control means for controlling the opening and closing of said passageway, the improvement comprising:
said valve control means including a valve element primarily responsive to pressure in said crank chamber and opening said passageway when the crank chamber pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the crank chamber pressure response point of said valve element with increasing discharge pressure.
said valve control means including a valve element primarily responsive to pressure in said crank chamber and opening said passageway when the crank chamber pressure is above a predetermined response point, and a valve shifting element coupled to said valve element by an elastic element, said valve shifting element responsive to changes in the discharge pressure for applying a force to said valve element to lower the crank chamber pressure response point of said valve element with increasing discharge pressure.
19. The refrigerant compressor recited in claim 18, said elastic element comprising a bias spring.
20. The refrigerant compressor recited in claim 18, said valve element comprising a bellows having a valve member attached at one end thereof, said bellows longitudinally expanding or contracting in response to the crank chamber pressure.
21. The refrigerant compressor recited in claim 18, said coupling means comprising a wobble plate disposed about said drive shaft, said inclined surface of said slant plate in close proximity to said wobble plate, said wobble plate linked to said pistons, rotational motion of said slant plate converted to nutational motion of said wobble plate to reciprocate said pistons in said cylinders.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62297700A JPH01142276A (en) | 1987-11-27 | 1987-11-27 | Variable displacement swash-plate type compressor |
| JP62-297700 | 1987-11-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1334839C true CA1334839C (en) | 1995-03-21 |
Family
ID=17850029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000584103A Expired - Fee Related CA1334839C (en) | 1987-11-27 | 1988-11-25 | Slant plate type compressor with variable displacement mechanism |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4960367A (en) |
| EP (1) | EP0318316B1 (en) |
| JP (1) | JPH01142276A (en) |
| KR (1) | KR960009853B1 (en) |
| AU (1) | AU609218B2 (en) |
| CA (1) | CA1334839C (en) |
| DE (1) | DE3863909D1 (en) |
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| US5189886A (en) * | 1987-09-22 | 1993-03-02 | Sanden Corporation | Refrigerating system having a compressor with an internally and externally controlled variable displacement mechanism |
| US5168716A (en) * | 1987-09-22 | 1992-12-08 | Sanden Corporation | Refrigeration system having a compressor with an internally and externally controlled variable displacement mechanism |
| EP0499343B1 (en) * | 1988-10-25 | 1994-09-14 | Sanden Corporation | Slant plate type compressor |
| JPH0331581A (en) * | 1989-06-28 | 1991-02-12 | Sanden Corp | Variable-capacity swash plate type compressor |
| JPH0343685A (en) * | 1989-07-05 | 1991-02-25 | Sanden Corp | Capacity variable type oscillating compressor |
| JP2943934B2 (en) * | 1990-03-20 | 1999-08-30 | サンデン株式会社 | Variable capacity swash plate compressor |
| JP2943935B2 (en) * | 1990-04-10 | 1999-08-30 | サンデン株式会社 | Variable capacity swash plate compressor |
| JPH0489873U (en) * | 1990-12-15 | 1992-08-05 | ||
| JPH04342883A (en) * | 1991-05-17 | 1992-11-30 | Sanden Corp | Variable delivery swash plate type compressor |
| US5242275A (en) * | 1992-06-22 | 1993-09-07 | Sanden Corporation | Slant plate type refrigerant compressor with variable displacement mechanism |
| AU644745B1 (en) * | 1992-07-08 | 1993-12-16 | Sanden Corporation | Slant plate type refrigerant compressor with variable displacement mechanism |
| JPH08326655A (en) * | 1995-06-05 | 1996-12-10 | Calsonic Corp | Swash plate compressor |
| JPH1162823A (en) * | 1997-08-08 | 1999-03-05 | Sanden Corp | Variable displacement compressor |
| JPH1182300A (en) * | 1997-09-05 | 1999-03-26 | Sanden Corp | Variable delivery compressor |
| JPH1193832A (en) * | 1997-09-25 | 1999-04-06 | Sanden Corp | Variable displacement compressor |
| JPH11280658A (en) | 1998-03-25 | 1999-10-15 | Sanden Corp | Capacity control valve of variable capacity compressor |
| JP3900669B2 (en) | 1998-04-16 | 2007-04-04 | 株式会社豊田自動織機 | Control valve and variable displacement compressor |
| JP4075129B2 (en) * | 1998-04-16 | 2008-04-16 | 株式会社豊田自動織機 | Control method of cooling device |
| JP4051134B2 (en) | 1998-06-12 | 2008-02-20 | サンデン株式会社 | Capacity control valve mechanism of variable capacity compressor |
| JP4111593B2 (en) | 1998-07-07 | 2008-07-02 | サンデン株式会社 | Capacity control valve mechanism of variable capacity compressor |
| JP4181274B2 (en) | 1998-08-24 | 2008-11-12 | サンデン株式会社 | Compressor |
| EP1026397A3 (en) * | 1999-02-01 | 2001-02-07 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Control valve in variable displacement compressor |
| JP3933369B2 (en) | 2000-04-04 | 2007-06-20 | サンデン株式会社 | Piston type variable capacity compressor |
| FR2809459A1 (en) | 2000-05-24 | 2001-11-30 | Sanden Corp | INCLINED CAM TYPE VARIABLE CYLINDER COMPRESSOR WITH CAPACITY CONTROL MECHANISM |
| JP4031945B2 (en) * | 2002-04-09 | 2008-01-09 | サンデン株式会社 | Volume control valve for variable capacity compressor |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4037993A (en) * | 1976-04-23 | 1977-07-26 | Borg-Warner Corporation | Control system for variable displacement compressor |
| US4428718A (en) * | 1982-02-25 | 1984-01-31 | General Motors Corporation | Variable displacement compressor control valve arrangement |
| JPH0637874B2 (en) * | 1984-12-28 | 1994-05-18 | 株式会社豊田自動織機製作所 | Variable capacity compressor |
| US4688997A (en) * | 1985-03-20 | 1987-08-25 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Variable displacement compressor with variable angle wobble plate and wobble angle control unit |
| US4685866A (en) * | 1985-03-20 | 1987-08-11 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Variable displacement wobble plate type compressor with wobble angle control unit |
| JPS62206277A (en) * | 1986-03-06 | 1987-09-10 | Toyoda Autom Loom Works Ltd | Mechanism for returning swing slant angle of wobble plate in swing swash plate type compressor |
| JPH0765567B2 (en) * | 1986-04-09 | 1995-07-19 | 株式会社豊田自動織機製作所 | Control Mechanism of Crank Chamber Pressure in Oscillating Swash Plate Compressor |
| JPS62253970A (en) * | 1986-04-25 | 1987-11-05 | Toyota Autom Loom Works Ltd | Variable capacity compressor |
| US4732544A (en) * | 1986-06-12 | 1988-03-22 | Diesel Kiki Co., Ltd. | Variable capacity wobble plate compressor |
| JPS6341677A (en) * | 1986-08-08 | 1988-02-22 | Sanden Corp | Variable capacity compressor |
| US4752189A (en) * | 1986-12-09 | 1988-06-21 | Diesel Kiki Co., Ltd. | Valve arrangement for a variable displacement compressor |
| JPH0649918Y2 (en) * | 1987-03-24 | 1994-12-14 | サンデン株式会社 | Variable capacity compressor |
| JP2511056B2 (en) * | 1987-07-23 | 1996-06-26 | サンデン株式会社 | Variable capacity swash plate compressor |
-
1987
- 1987-11-27 JP JP62297700A patent/JPH01142276A/en active Granted
-
1988
- 1988-11-25 CA CA000584103A patent/CA1334839C/en not_active Expired - Fee Related
- 1988-11-25 AU AU25958/88A patent/AU609218B2/en not_active Ceased
- 1988-11-25 EP EP88311201A patent/EP0318316B1/en not_active Expired - Lifetime
- 1988-11-25 DE DE8888311201T patent/DE3863909D1/en not_active Expired - Lifetime
- 1988-11-28 KR KR1019880015685A patent/KR960009853B1/en not_active IP Right Cessation
- 1988-11-28 US US07/276,798 patent/US4960367A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| AU2595888A (en) | 1989-06-01 |
| JPH0353474B2 (en) | 1991-08-15 |
| KR890008449A (en) | 1989-07-10 |
| EP0318316A1 (en) | 1989-05-31 |
| DE3863909D1 (en) | 1991-08-29 |
| AU609218B2 (en) | 1991-04-26 |
| US4960367A (en) | 1990-10-02 |
| JPH01142276A (en) | 1989-06-05 |
| EP0318316B1 (en) | 1991-07-24 |
| KR960009853B1 (en) | 1996-07-24 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |