US3877837A - Compressor control with thermal density sensor - Google Patents
Compressor control with thermal density sensor Download PDFInfo
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- US3877837A US3877837A US428831A US42883173A US3877837A US 3877837 A US3877837 A US 3877837A US 428831 A US428831 A US 428831A US 42883173 A US42883173 A US 42883173A US 3877837 A US3877837 A US 3877837A
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- compression mechanism
- motor
- circuit state
- temperature
- predetermined value
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
- F25B49/022—Compressor control arrangements
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- 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
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/02—Stopping, starting, unloading or idling control
- F04B49/022—Stopping, starting, unloading or idling control by means of pressure
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- 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
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/10—Other safety measures
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B31/00—Compressor arrangements
- F25B31/02—Compressor arrangements of motor-compressor units
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
- H02K11/25—Devices for sensing temperature, or actuated thereby
Definitions
- ABSTRACT Freeh Attorney, Agent, or Firm-Molinare, Allegretti, Newitt & Witcoff
- the disclosure describes a thermal density sensor for preventing the start-up of a compressor motor operatively connected to the piston and cylinder means of a compression mechanism when the temperature of the compression mechanism is below a predetermined value to prevent damage to the running parts of the compression mechanism due to inadequate lubrication.
- Control circuitry for operating the compressor motor is contained in a single control box on the compressor so that the wiring of the circuitry is simplified. The control circuitry is entirely factory wired and the circuitry is maintained in a tamper-proof environment.
- FIGJ 82 38 us I2 48 on.
- This invention relates to an improved refrigerant compressor of the type housed in an outer casing and more particularly relates to improved apparatus for preventing the start up ofthe compressor if the temperature of the running parts within the outer casing is below a predetermined value.
- Modern compressors also utilize metals having different coefficients of expansion. For example, it is not uncommon for a compressor to utilize an aluminum piston rod that is fitted with a steel wrist pin. If the temperature of these components is too low, the diverse coefficients of expansion of the metals may reduce bearing clearances below acceptable tolerances. This condition, coupled with inadequate lubrication, can cause excessive wear or damage to the components.
- a compressor which is started-up in a cold condition may experience valve flutter.
- the resonant condition set up by the valve flutter can cause annoying noise and also can reduce the operating efficiency of the compressor.
- thermal density sensor which is responsive to the temperature within an outer casing that surrounds the compression mechanism of a refrigerant compressors.
- the thermal density sensor is arranged to prevent the start-up of a motor which drives the compression mechanism when the temperature of the running parts in the compression mechanism is below a predetermined value.
- control circuitry required to protect and operate the compressor motor is contained within a single control box mounted on the outer casing or within the outer casing itself.
- This arrangement facilitates the wiring of the circuitry during manufacture and thereby reduces the cost of the compressor.
- the control box package is factory wired and tested, thus reducing chance of field problems due to the faulty hook-up of the separate elements of the control circuit in the field.
- the control box prevents theft of and tampering with the sensitive control circuitry.
- Still another object of the invention is to provide a thermal density sensor in physical contact with the block of a compression mechanism which prevents an electrical motor from driving the running parts of the compression mechanism if the temperature sensed by the thermal density sensor is too low.
- Yet another object of the present invention is to enclose all electrical control circuitry needed to operate and protect the motor of a compressor within a single control box or an outer casing surrounding the compressor.
- FIG. 1 is an isometric, fragmentary, partially crosssectional view of a refrigerant compressor embodying control apparatus made in accordance with the present invention.
- FIG. 2 is a top plan view of the control box shown in FIG. 1 with the top cover removed;
- FIG. 3 is a top plan view of a control box showing an alternative arrangement of the components illustrated in FIG. 2;
- FIG. 4 is an electrical schematic diagram of the motor control circuitry contained within the control box illustrated in FIGS. 1 and 2.
- Compressor 10 comprises a sealed outer casing 11 which comprises an upper shell 12 (having a top surface 13) that is welded to a lower shell 14.
- a plurality of legs 16 are suitably secured to compressor 10 to support it in an upright position.
- the compression mechanism comprises a compressor block 24 which defines a cylinder 26, together with additional cylinders (not shown).
- a movable piston 28 reciprocates within cylinder 26 in order to compress a refrigerant vapor.
- Additional pistons like piston 28, reciprocate in the additional cylinders, not shown.
- Each of the pistons is driven from a vertical disposed drive shaft 30.
- the lower portion of the outer casing froms an oil sump in which the oil level is visible through an oil sight glass 31.
- An electric motor 32 is used to drive compression mechanism 22.
- the motor comprises a stator 34 which includes windings 36.
- a rotatable rotor 38 is inductively coupled to stator 34 and is mechanically coupled to drive shaft 30.
- valve assembly 40 Provided at the end of each cylinder, including cylinder 26, and closing the end of each cylinder cavity, is a valve assembly, such as a valve assembly 40.
- the valve assembly includes a discharge valve and a suction valve.
- the suction valve opens on the suction stroke of piston 28 to permit refrigerant gas (suction gas) to enter cylinder 26 through a suction line 46.
- the suction valve closes and the discharge valve opens to permit the flow of compressed refrigerant gas to a discharge muffler in the compression mechanism and then to discharge lines 48.
- the compressed gas is transmitted through the discharge lines to a conventional condensor (not shown).
- the sensor preferably comprises a thermostat which is screwed into compressor block 24 in the position shown in FIG. 1.
- the thermostat is preferably the same type of temperature limiting device shown in US. Pat. No. 3,278,l ll (Parker Oct. ll, I966) in which switch contacts 58 (FIG. 4) and a temperature responsive element are contained within a single housing.
- Sensor 50 is set to open electrical contacts 58 at about 22F, plus or minus 3F. and to close contacts 58 at about 32F, plus or minus 3F.
- Contacts 58 are electrically connected to other components of the compressor by conductors 54 and 55 that are attached to terminals 54T and 55T (FIG. 2).
- sensor 50 is an important feature because it prevents the start-up of motor 32 when the temperature of the running parts of the compression mechanism is below a predetermined value which inhibits adequate lubrication.
- control box assembly 62 incorporating all of the electrical control circuitry for the compressor therein.
- the control box assembly 62 which comprises a top 64 and sidewalls 66-69, is physically coupled to top surface 13 of outer casing 11.
- FIG. 2 illustrates the layout of an electrical control assembly 72 contained within control box 62. Most of the wiring is not illustrated so that the layout of the components can be made easily seen.
- the control assembly includes a contactor 74, as well as compressor terminals T1-T6.
- a motor protection module 76 opens switch contacts 77 (FIG. 4) if detector 78 (shown schematically in the motor windings) senses a temperature higher than a desired value. Detector 78 is electrically connected to protection terminal block through conductors 79 and 80. The operation of switch contacts 77 is such that terminals 79T and 80T are closed if the motor temperature is sufficiently low and are opened if the temperature exceeds a preset value.
- Control assembly 72 also comprises a high pressure switch assembly 82 located in the discharge gas spud 99 on the exterior of the outer casing.
- Switch contacts 84 (FIG. 4) are connected across terminals 86T and 87T (FIG. 2).
- the control assembly also includes a low pressure switch assembly 90 that incorporates switch contacts 92.
- the switch contacts are connected across terminals MT and 95T (FIG. 2).
- Control assembly 72 further comprises a discharge gas temperature sensor 100 which is the same type of device as sensor 50 described above.
- Sensor 100 includes a set of switch contacts 102 which are connected by conductors 104 and 105 to terminals 104T and 105T located in control box 62.
- the discharge gas temperature sensor senses discharge gas temperature at its source so as to terminate compressor motor operation if the discharge gas temperature exceeds a predetermined high value (on the order of 300F) to prevent breakdown of the compressor oil and damage to the running parts of the compression mechanism.
- the various control terminals are interconnected by conductors 108 to form the series pilot circuit schematically illustrated in FIG. 4.
- the pilot circuit also includes a 2 ampere fuse 110 which is held by a fuse holder 112.
- a conductor 114 is connected to a source of AC voltage, such as a low voltage transformer. AC power is supplied to the control box through a shielded cable 116.
- thermal density sensor 50 opens switch contacts 58, thereby preventing motor 32 from starting up and damaging the compression mechanism. If highpressure switch assembly 82 detects pressure aboveapproximately 410 P816 in discharge lines 48, switch contacts 84 are open circuited or opened to stop motor 32. Likewise, if a temperature above approximately 300F. in the discharge manifold is detected by discharge gas temperature sensor 100, switch contacts 102 are opened to stop motor 32.
- control motor 32 the electrical terminals necessary to control motor 32 are all contained within control box 62,.thereby facilitating the wiring of the controls.
- Contactor 74 is advantageously placed on top of module 76, thereby conserving space inside the control box.
- FIG. 3 illustrates an alternative embodiment in which contactor 74 is placed along side module 76. Otherwise, as indicated by the like-numbered elements, the
- FIGS. 2 and 3 are identical.
- the thermal density sensor will prevent operation of the compressor motor until the ambient heats up.
- the compressor will remain inoperative until the sun heats the ambient and by heat transfer heats the running parts and lubricant within the outer casing.
- a control for external heat may be included in the control circuitry. Should there be a demand for compressor operation negated only by the thermal density sensor sensing too low a temperature, then an external heat source or additional crankcase heat will be actuated to elevate the temperature within the outer casing.
- accompa compression mechanism comprising a block for defining a cylinder, a movable member inside the cylinder receiving refrigerant gas and discharging the compressed refrigerant gas through a discharge line, shaft means for moving the movable member, a motor for rotating the shaft means and control means for controlling the operation of the motor, the improvement comprising thermal densiy sensor means including a thermostat mounted on the compression mechanism responsive to the temperature of the compression mechanism for preventingthe start-up of the motor when the temperature of the compression mechanism is below a predetermined value to prevent damage to the compression mechanism.
- control means comprises:
- high pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the discharge line rises above a predetermined value
- low pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the outer casing falls below a predetermined value
- motor protection switch means for switching between a closed circuit state and an open circuit state in response to a predetermined condition of the motor
- discharge gas switch means for operating between a closed circuit state and an open circuit state when the temperature of the discharge gas rises above a predetermined value.
- control means further comprises:
- terminal means located inside the control box
- first conductor means for connecting the terminal means to the high and low pressure switch means, motor protection switch means, and discharge gas switch means;
- second conductor means located inside the control box for interconnecting the terminal means
- a method of operating a refrigerant compressor of the type having a compression mechanism with an outer casing and motor means for actuating the running parts in the compression mechanism comprising the steps of preventing start-up of the motor means when the temperature of the running parts in the compression mechanism is below a predetermined value so as to prevent damage to the running parts due to inadequate lubrication or inadequate clearance.
Abstract
The disclosure describes a thermal density sensor for preventing the start-up of a compressor motor operatively connected to the piston and cylinder means of a compression mechanism when the temperature of the compression mechanism is below a predetermined value to prevent damage to the running parts of the compression mechanism due to inadequate lubrication. Control circuitry for operating the compressor motor is contained in a single control box on the compressor so that the wiring of the circuitry is simplified. The control circuitry is entirely factory wired and the circuitry is maintained in a tamper-proof environment.
Description
United States Patent [191 Parker et al.
[ 51 Apr. 15, 1975 COMPRESSOR CONTROL WITH THERMAL DENSITY SENSOR [75] Inventors: Sidney A. Parker, Fort Worth;
Richard E. Cawley, Hurst, both of Tex.
[73] Assignee: Lennox Industries, Inc., Fort Worth,
Tex.
[22] Filed: Dec. 27, 1973 [21] Appl. No.: 428,831
[52] US. Cl. 417/25; 417/32; 417/53 [51] Int. Cl. F04b 49/00 [58] Field of Search 417/32, 44, 13, 17, 53; 123/198 D [56] References Cited UNITED STATES PATENTS 1,838,409 12/1931 King et al. 123/198 D 2,125,066 7/1938 Cox et al. 123/198 D 3,250,461 5/1966 Parker 417/902 3,278,111 10/1966 Parker 417/32 3,383,031 5/1968 Ellis et al. 417/44 3,673,811 8/1972 Adams et al. 417/13 Primary Examiner-William L. Freeh Attorney, Agent, or Firm-Molinare, Allegretti, Newitt & Witcoff [57] ABSTRACT The disclosure describes a thermal density sensor for preventing the start-up of a compressor motor operatively connected to the piston and cylinder means of a compression mechanism when the temperature of the compression mechanism is below a predetermined value to prevent damage to the running parts of the compression mechanism due to inadequate lubrication. Control circuitry for operating the compressor motor is contained in a single control box on the compressor so that the wiring of the circuitry is simplified. The control circuitry is entirely factory wired and the circuitry is maintained in a tamper-proof environment.
5 Claims, 4 Drawing Figures PATENTEDAPR 1 5197s 877 837 SHEET 1 0F 2 66 FIGJ 82 38 us I2 48 on.
36 ,R o ".553 3 48 I I E ri I l 9 79 f 32 54 i 1 H48 80 4 4 2o I 3 ,J IO 5 I I05 I l i 0 I 1 o as; 78 I00 I g 6 IS 46 o I4 22 4o L I I I6 FIG.4
THERMAL MOTOR DENS'TY PROTECTOR LOW i? W in- EI 4 4 4| /r DISCHARGE LHE I T0 55 54 GAS A.C.
5 THERMOSTAT 77 92 SOURCE 84 SWITCH COMPRESSOR CONTROL WITH THERMAL DENSITY SENSOR BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to an improved refrigerant compressor of the type housed in an outer casing and more particularly relates to improved apparatus for preventing the start up ofthe compressor if the temperature of the running parts within the outer casing is below a predetermined value.
Many refrigerant compressors utilize an oil pump which lubricates the compression mechanism by centrifugal force. One such lubrication system is illustrated in US. Pat. No. 3,584,980 (Cawley June 15, 1971). As shown in the Cawley Patent, the oil must travel from an oil sump in a vertical direction through relatively small passages in order to lubricate vital parts. If the compression mechanism is too cold, the viscosity of the oil will be sufficiently thick to prevent adequate flow through the passageways. As a result, bearing and journal parts of the compression mechanism may not receive adequate lubrication and could be severely damaged.
Modern compressors also utilize metals having different coefficients of expansion. For example, it is not uncommon for a compressor to utilize an aluminum piston rod that is fitted with a steel wrist pin. If the temperature of these components is too low, the diverse coefficients of expansion of the metals may reduce bearing clearances below acceptable tolerances. This condition, coupled with inadequate lubrication, can cause excessive wear or damage to the components.
In addition to the foregoing difficulties, the applicants have noted that a compressor which is started-up in a cold condition may experience valve flutter. The resonant condition set up by the valve flutter can cause annoying noise and also can reduce the operating efficiency of the compressor.
The applicants have discovered that the foregoing undesirable conditions can be alleviated by providing a thermal density sensor which is responsive to the temperature within an outer casing that surrounds the compression mechanism of a refrigerant compressors. Preferably, the thermal density sensor is arranged to prevent the start-up of a motor which drives the compression mechanism when the temperature of the running parts in the compression mechanism is below a predetermined value.
According to another feature of the invention, the control circuitry required to protect and operate the compressor motor is contained within a single control box mounted on the outer casing or within the outer casing itself. This arrangement facilitates the wiring of the circuitry during manufacture and thereby reduces the cost of the compressor. The control box package is factory wired and tested, thus reducing chance of field problems due to the faulty hook-up of the separate elements of the control circuit in the field. In addition, the control box prevents theft of and tampering with the sensitive control circuitry.
Accordingly, it is an object of the present invention to provide apparatus for preventing the start-up of a refrigerant compression mechanism when the temperature of the running parts of the compression mechanism is below a predetermined value.
It is another object of the invention to provide a thermal density sensor in heat transfer relationship with the compression mechanism so that the temperature of the mechanism can be more accurately sensed.
Still another object of the invention is to provide a thermal density sensor in physical contact with the block of a compression mechanism which prevents an electrical motor from driving the running parts of the compression mechanism if the temperature sensed by the thermal density sensor is too low.
Yet another object of the present invention is to enclose all electrical control circuitry needed to operate and protect the motor of a compressor within a single control box or an outer casing surrounding the compressor.
BRIEF DESCRIPTION OF THE DRAWING These and other objects, advantages, and features of the present invention will hereafter appear in connection with the accompanying drawings wherein:
FIG. 1 is an isometric, fragmentary, partially crosssectional view of a refrigerant compressor embodying control apparatus made in accordance with the present invention.
FIG. 2 is a top plan view of the control box shown in FIG. 1 with the top cover removed;
FIG. 3 is a top plan view of a control box showing an alternative arrangement of the components illustrated in FIG. 2; and
FIG. 4 is an electrical schematic diagram of the motor control circuitry contained within the control box illustrated in FIGS. 1 and 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, there is illustrated a refrigerant compressor 10 embodying a preferred form of the present invention. Compressor 10 comprises a sealed outer casing 11 which comprises an upper shell 12 (having a top surface 13) that is welded to a lower shell 14. A plurality of legs 16 are suitably secured to compressor 10 to support it in an upright position.
Resiliently supported within the outer casing by resilient coil spring means 20 is a compression mechanism 22. The compression mechanism comprises a compressor block 24 which defines a cylinder 26, together with additional cylinders (not shown). A movable piston 28 reciprocates within cylinder 26 in order to compress a refrigerant vapor. Additional pistons like piston 28, reciprocate in the additional cylinders, not shown. Each of the pistons is driven from a vertical disposed drive shaft 30. The lower portion of the outer casing froms an oil sump in which the oil level is visible through an oil sight glass 31.
An electric motor 32 is used to drive compression mechanism 22. The motor comprises a stator 34 which includes windings 36. A rotatable rotor 38 is inductively coupled to stator 34 and is mechanically coupled to drive shaft 30.
Provided at the end of each cylinder, including cylinder 26, and closing the end of each cylinder cavity, is a valve assembly, such as a valve assembly 40. The valve assembly includes a discharge valve and a suction valve. The suction valve opens on the suction stroke of piston 28 to permit refrigerant gas (suction gas) to enter cylinder 26 through a suction line 46. On the compression stroke of piston 28, the suction valve closes and the discharge valve opens to permit the flow of compressed refrigerant gas to a discharge muffler in the compression mechanism and then to discharge lines 48. The compressed gas is transmitted through the discharge lines to a conventional condensor (not shown).
One important feature is the provision of a thermal density sensor 50 inside the outer casing 11. The sensor preferably comprises a thermostat which is screwed into compressor block 24 in the position shown in FIG. 1. The thermostat is preferably the same type of temperature limiting device shown in US. Pat. No. 3,278,l ll (Parker Oct. ll, I966) in which switch contacts 58 (FIG. 4) and a temperature responsive element are contained within a single housing. Sensor 50 is set to open electrical contacts 58 at about 22F, plus or minus 3F. and to close contacts 58 at about 32F, plus or minus 3F. Contacts 58 are electrically connected to other components of the compressor by conductors 54 and 55 that are attached to terminals 54T and 55T (FIG. 2). As previously explained, sensor 50 is an important feature because it prevents the start-up of motor 32 when the temperature of the running parts of the compression mechanism is below a predetermined value which inhibits adequate lubrication.
Another feature is the provision of a control box assembly 62 incorporating all of the electrical control circuitry for the compressor therein. As shown in FIG. 1, the control box assembly 62, which comprises a top 64 and sidewalls 66-69, is physically coupled to top surface 13 of outer casing 11.
FIG. 2 illustrates the layout of an electrical control assembly 72 contained within control box 62. Most of the wiring is not illustrated so that the layout of the components can be made easily seen. The control assembly includes a contactor 74, as well as compressor terminals T1-T6. A motor protection module 76 opens switch contacts 77 (FIG. 4) if detector 78 (shown schematically in the motor windings) senses a temperature higher than a desired value. Detector 78 is electrically connected to protection terminal block through conductors 79 and 80. The operation of switch contacts 77 is such that terminals 79T and 80T are closed if the motor temperature is sufficiently low and are opened if the temperature exceeds a preset value.
The control assembly also includes a low pressure switch assembly 90 that incorporates switch contacts 92. The switch contacts are connected across terminals MT and 95T (FIG. 2).
As shown in FIG. 2, the various control terminals are interconnected by conductors 108 to form the series pilot circuit schematically illustrated in FIG. 4. The pilot circuit also includes a 2 ampere fuse 110 which is held by a fuse holder 112. A conductor 114 is connected to a source of AC voltage, such as a low voltage transformer. AC power is supplied to the control box through a shielded cable 116.
In operation, each of the switches shown in FIG. 4
must be in a closed circuit condition in order for motor 32 to be operated. For example, if the temperature of the running parts of the compression assembly, for example, the drive shaft, piston rods, and wrist pin, is too low, thermal density sensor 50 opens switch contacts 58, thereby preventing motor 32 from starting up and damaging the compression mechanism. If highpressure switch assembly 82 detects pressure aboveapproximately 410 P816 in discharge lines 48, switch contacts 84 are open circuited or opened to stop motor 32. Likewise, if a temperature above approximately 300F. in the discharge manifold is detected by discharge gas temperature sensor 100, switch contacts 102 are opened to stop motor 32. In a similar manner, if detector 78 senses that the temperature of motor 32 is abnormally high, or if low pressure switch assembly detects pressure below approximately 25 P516 inside outer casing 11, switch contacts 77 and 92, respectively, are open in order to stop motor 32.
Referring to FIG. 2, it should be noted that the electrical terminals necessary to control motor 32 are all contained within control box 62,.thereby facilitating the wiring of the controls. Contactor 74 is advantageously placed on top of module 76, thereby conserving space inside the control box.
FIG. 3 illustrates an alternative embodiment in which contactor 74 is placed along side module 76. Otherwise, as indicated by the like-numbered elements, the
embodiments of the control boxes shown in FIGS. 2 and 3 are identical.
It will be understood that the thermal density sensor will prevent operation of the compressor motor until the ambient heats up. In one aspect, the compressor will remain inoperative until the sun heats the ambient and by heat transfer heats the running parts and lubricant within the outer casing. In another aspect, a control for external heat may be included in the control circuitry. Should there be a demand for compressor operation negated only by the thermal density sensor sensing too low a temperature, then an external heat source or additional crankcase heat will be actuated to elevate the temperature within the outer casing.
Those skilled in the artwill recognize that only two preferred embodiments of the invention have been disclosed herein, and that these embodiments may be altered and modified without departing from the spirit and scope of the invention as defined in the accompa compression mechanism comprising a block for defining a cylinder, a movable member inside the cylinder receiving refrigerant gas and discharging the compressed refrigerant gas through a discharge line, shaft means for moving the movable member, a motor for rotating the shaft means and control means for controlling the operation of the motor, the improvement comprising thermal densiy sensor means including a thermostat mounted on the compression mechanism responsive to the temperature of the compression mechanism for preventingthe start-up of the motor when the temperature of the compression mechanism is below a predetermined value to prevent damage to the compression mechanism.
2. Apparatus, as claimed in claim 1, wherein the ther mostat comprises switch contacts operated when the temperature of the block decreases below a predetermined value.
3. Apparatus, as claimed in claim 2, wherein the control means comprises:
high pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the discharge line rises above a predetermined value;
low pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the outer casing falls below a predetermined value;
motor protection switch means for switching between a closed circuit state and an open circuit state in response to a predetermined condition of the motor; and
discharge gas switch means for operating between a closed circuit state and an open circuit state when the temperature of the discharge gas rises above a predetermined value.
4. Apparatus, as claimed in claim 3, wherein the control means further comprises:
an enclosed control box mounted on the outer casing;
terminal means located inside the control box;
first conductor means for connecting the terminal means to the high and low pressure switch means, motor protection switch means, and discharge gas switch means;
second conductor means located inside the control box for interconnecting the terminal means;
a contactor located inside the control box; and
a module located inside the control box for operating the motor protection switch means.
5. A method of operating a refrigerant compressor of the type having a compression mechanism with an outer casing and motor means for actuating the running parts in the compression mechanism, comprising the steps of preventing start-up of the motor means when the temperature of the running parts in the compression mechanism is below a predetermined value so as to prevent damage to the running parts due to inadequate lubrication or inadequate clearance.
Claims (5)
1. In a refrigerant compressor of the type having a compression mechanism within an outer casing, said compression mechanism comprising a block for defining a cylinder, a movable member inside the cylinder receiving refrigerant gas and discharging the compressed refrigerant gas through a discharge line, shaft means for moving the movable member, a motor for rotating the shaft means and control means for controlling the operation of the motor, the improvement comprising thermal densiy sensor means including a thermostat mounted on the compression mechanism responsive to the temperature of the compression mechanism for preventing the start-up of the motor when the temperature of the compression mechanism is below a predetermined value to prevent damage to the compression mechanism.
2. Apparatus, as claimed in claim 1, wherein the thermostat comprises switch contacts operated when the temperature of the block decreases below a predetermined value.
3. Apparatus, as claimed in claim 2, wherein the control means comprises: high pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the discharge line rises above a predetermined value; low pressure switch means for switching between a closed circuit state and an open circuit state when the pressure in the outer casing falls below a predetermined value; motor protection switch means for switching between a closed circuit state and an open circuit state in response to a predetermined condition of the motor; and discharge gas switch means for operating between a closed circuit state and an open circuit state when the temperature of the discharge gas rises above a predetermined value.
4. Apparatus, as claimed in claim 3, wherein the control means further comprises: an enclosed control box mounted on the outer casing; tErminal means located inside the control box; first conductor means for connecting the terminal means to the high and low pressure switch means, motor protection switch means, and discharge gas switch means; second conductor means located inside the control box for interconnecting the terminal means; a contactor located inside the control box; and a module located inside the control box for operating the motor protection switch means.
5. A method of operating a refrigerant compressor of the type having a compression mechanism with an outer casing and motor means for actuating the running parts in the compression mechanism, comprising the steps of preventing start-up of the motor means when the temperature of the running parts in the compression mechanism is below a predetermined value so as to prevent damage to the running parts due to inadequate lubrication or inadequate clearance.
Priority Applications (10)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US428831A US3877837A (en) | 1973-12-27 | 1973-12-27 | Compressor control with thermal density sensor |
NL7416308A NL7416308A (en) | 1973-12-27 | 1974-12-13 | COOLING COMPRESSOR AND PROTECTION SWITCH EAR. |
SE7415685A SE7415685L (en) | 1973-12-27 | 1974-12-13 | |
DK652774A DK652774A (en) | 1973-12-27 | 1974-12-13 | |
AU76510/74A AU7651074A (en) | 1973-12-27 | 1974-12-17 | Compressor control with thermal density sensor |
IT54662/74A IT1026089B (en) | 1973-12-27 | 1974-12-19 | IMPROVEMENT IN COMPRESSORS FOR REFRIGERATORS |
GB5493174A GB1442557A (en) | 1973-12-27 | 1974-12-19 | Refrigerant compressor |
CA216,539A CA1029117A (en) | 1973-12-27 | 1974-12-20 | Compressor control with thermal density sensor |
JP50003003A JPS5097916A (en) | 1973-12-27 | 1974-12-24 | |
FR7442909A FR2256382B3 (en) | 1973-12-27 | 1974-12-26 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US428831A US3877837A (en) | 1973-12-27 | 1973-12-27 | Compressor control with thermal density sensor |
Publications (1)
Publication Number | Publication Date |
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US3877837A true US3877837A (en) | 1975-04-15 |
Family
ID=23700576
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US428831A Expired - Lifetime US3877837A (en) | 1973-12-27 | 1973-12-27 | Compressor control with thermal density sensor |
Country Status (10)
Country | Link |
---|---|
US (1) | US3877837A (en) |
JP (1) | JPS5097916A (en) |
AU (1) | AU7651074A (en) |
CA (1) | CA1029117A (en) |
DK (1) | DK652774A (en) |
FR (1) | FR2256382B3 (en) |
GB (1) | GB1442557A (en) |
IT (1) | IT1026089B (en) |
NL (1) | NL7416308A (en) |
SE (1) | SE7415685L (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4059366A (en) * | 1976-03-26 | 1977-11-22 | Tecumseh Products Company | Thermal overload protective system |
US4621438A (en) * | 1980-12-04 | 1986-11-11 | Donald M. Thompson | Energy efficient clothes dryer |
US4936747A (en) * | 1987-05-19 | 1990-06-26 | Tokico Ltd. | Compressor with condition responsive cut-off means |
US6142741A (en) * | 1995-02-09 | 2000-11-07 | Matsushita Electric Industrial Co., Ltd. | Hermetic electric compressor with improved temperature responsive motor control |
US20090185921A1 (en) * | 2008-01-17 | 2009-07-23 | Bitzer Scroll Inc. | Scroll Compressor Having Standardized Power Strip |
US20100028184A1 (en) * | 2008-07-31 | 2010-02-04 | Hahn Gregory W | Temperature protection switch biased against scroll compressor shell |
WO2011117341A1 (en) * | 2010-03-25 | 2011-09-29 | Continental Teves Ag & Co. Ohg | Method for regulating a compressor |
US20120294733A1 (en) * | 2010-01-20 | 2012-11-22 | Daikin Industries, Ltd. | Compressor |
US20160061505A1 (en) * | 2012-11-16 | 2016-03-03 | Emerson Climate Technologies, Inc. | Compressor crankcase heating control systems and methods |
US9879894B2 (en) | 2013-09-19 | 2018-01-30 | Emerson Climate Technologies, Inc. | Compressor crankcase heating control systems and methods |
US10161400B2 (en) | 2014-07-21 | 2018-12-25 | Danfoss Scroll Technologies, Llc | Snap-in temperature sensor for scroll compressor |
CZ307581B6 (en) * | 2007-12-10 | 2018-12-27 | Mitsubishi Electric Corporation | Hermetically sealed compressor |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62153583A (en) * | 1985-12-27 | 1987-07-08 | Kyodo Gijutsu Center:Kk | Abnormality detecting method and device for reciprocation type compressor |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1838409A (en) * | 1928-06-05 | 1931-12-29 | Pratt & Whitney Aircraft Compa | Internal combustion engine |
US2125066A (en) * | 1937-04-01 | 1938-07-26 | Fed Aircraft Corp | Internal combustion engine control |
US3250461A (en) * | 1964-09-08 | 1966-05-10 | Lennox Ind Inc | Hermetic compressor assembly |
US3278111A (en) * | 1964-07-27 | 1966-10-11 | Lennox Ind Inc | Device for detecting compressor discharge gas temperature |
US3383031A (en) * | 1965-10-24 | 1968-05-14 | Lennox Ind Inc | Hermetic compressor pressure switch |
US3673811A (en) * | 1970-09-15 | 1972-07-04 | Ranco Inc | Control device for pressure lubricated compressors |
-
1973
- 1973-12-27 US US428831A patent/US3877837A/en not_active Expired - Lifetime
-
1974
- 1974-12-13 SE SE7415685A patent/SE7415685L/xx not_active Application Discontinuation
- 1974-12-13 DK DK652774A patent/DK652774A/da unknown
- 1974-12-13 NL NL7416308A patent/NL7416308A/en unknown
- 1974-12-17 AU AU76510/74A patent/AU7651074A/en not_active Expired
- 1974-12-19 IT IT54662/74A patent/IT1026089B/en active
- 1974-12-19 GB GB5493174A patent/GB1442557A/en not_active Expired
- 1974-12-20 CA CA216,539A patent/CA1029117A/en not_active Expired
- 1974-12-24 JP JP50003003A patent/JPS5097916A/ja active Pending
- 1974-12-26 FR FR7442909A patent/FR2256382B3/fr not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1838409A (en) * | 1928-06-05 | 1931-12-29 | Pratt & Whitney Aircraft Compa | Internal combustion engine |
US2125066A (en) * | 1937-04-01 | 1938-07-26 | Fed Aircraft Corp | Internal combustion engine control |
US3278111A (en) * | 1964-07-27 | 1966-10-11 | Lennox Ind Inc | Device for detecting compressor discharge gas temperature |
US3250461A (en) * | 1964-09-08 | 1966-05-10 | Lennox Ind Inc | Hermetic compressor assembly |
US3383031A (en) * | 1965-10-24 | 1968-05-14 | Lennox Ind Inc | Hermetic compressor pressure switch |
US3673811A (en) * | 1970-09-15 | 1972-07-04 | Ranco Inc | Control device for pressure lubricated compressors |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4059366A (en) * | 1976-03-26 | 1977-11-22 | Tecumseh Products Company | Thermal overload protective system |
US4621438A (en) * | 1980-12-04 | 1986-11-11 | Donald M. Thompson | Energy efficient clothes dryer |
US4936747A (en) * | 1987-05-19 | 1990-06-26 | Tokico Ltd. | Compressor with condition responsive cut-off means |
US6142741A (en) * | 1995-02-09 | 2000-11-07 | Matsushita Electric Industrial Co., Ltd. | Hermetic electric compressor with improved temperature responsive motor control |
CZ307581B6 (en) * | 2007-12-10 | 2018-12-27 | Mitsubishi Electric Corporation | Hermetically sealed compressor |
US20090185921A1 (en) * | 2008-01-17 | 2009-07-23 | Bitzer Scroll Inc. | Scroll Compressor Having Standardized Power Strip |
US7997877B2 (en) * | 2008-01-17 | 2011-08-16 | Bitzer Kuhlmaschinenbau Gmbh | Scroll compressor having standardized power strip |
US20100028184A1 (en) * | 2008-07-31 | 2010-02-04 | Hahn Gregory W | Temperature protection switch biased against scroll compressor shell |
US20120294733A1 (en) * | 2010-01-20 | 2012-11-22 | Daikin Industries, Ltd. | Compressor |
US9568000B2 (en) * | 2010-01-20 | 2017-02-14 | Daikin Industries, Ltd. | Compressor |
CN102822526A (en) * | 2010-03-25 | 2012-12-12 | 大陆-特韦斯贸易合伙股份公司及两合公司 | Method for regulating a compressor |
CN102822526B (en) * | 2010-03-25 | 2014-12-24 | 大陆-特韦斯贸易合伙股份公司及两合公司 | Method for regulating a compressor |
US9243627B2 (en) | 2010-03-25 | 2016-01-26 | Continetal Teves Ag & Co. Ohg | Compressor temperature control by indirect temperature measurement |
WO2011117341A1 (en) * | 2010-03-25 | 2011-09-29 | Continental Teves Ag & Co. Ohg | Method for regulating a compressor |
US20160061505A1 (en) * | 2012-11-16 | 2016-03-03 | Emerson Climate Technologies, Inc. | Compressor crankcase heating control systems and methods |
US9851135B2 (en) * | 2012-11-16 | 2017-12-26 | Emerson Climate Technologies, Inc. | Compressor crankcase heating control systems and methods |
US10801764B2 (en) | 2012-11-16 | 2020-10-13 | Emerson Climate Technologies, Inc. | Compressor crankcase heating control systems and methods |
US9879894B2 (en) | 2013-09-19 | 2018-01-30 | Emerson Climate Technologies, Inc. | Compressor crankcase heating control systems and methods |
US10161400B2 (en) | 2014-07-21 | 2018-12-25 | Danfoss Scroll Technologies, Llc | Snap-in temperature sensor for scroll compressor |
Also Published As
Publication number | Publication date |
---|---|
DK652774A (en) | 1975-08-18 |
IT1026089B (en) | 1978-09-20 |
FR2256382A1 (en) | 1975-07-25 |
FR2256382B3 (en) | 1977-09-23 |
CA1029117A (en) | 1978-04-04 |
JPS5097916A (en) | 1975-08-04 |
SE7415685L (en) | 1975-06-30 |
GB1442557A (en) | 1976-07-14 |
AU7651074A (en) | 1976-06-17 |
NL7416308A (en) | 1975-07-01 |
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