US3781136A

US3781136A - Combination centrifugal and viscous shear rotary pump

Info

Publication number: US3781136A
Application number: US00060186A
Authority: US
Inventors: O Jacobson
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-03-14
Filing date: 1970-06-30
Publication date: 1973-12-25
Anticipated expiration: 1990-12-25

Abstract

A combination centrifugal and viscous shear rotary pump of a disc impeller type with extremely shallow spiral grooves fabricated in both sides of the disk and in close proximity to smooth stator surfaces so as to cause a high viscous shear in a low viscosity fluid to effect an improved pressure rise in the spiral grooves as the disk rotates in a sense aiding in a centrifugal pumping action of the impeller disk. In operation, the disk floats hydrodynamically between the stator faces and on a center journal bearing so that there are no wear points during operation of the rotary pump which is particularly adapted for use in an arrangement for supplying fluid pressure to hydrostatically supported bearings of a gyroscope.

Description

Jacobson COMBENATION CENTRIFUGAL AND VHSCOUS SHEAR ROTARY PUMP I Dec. 25, 1973 104,277 /1926 Austria 417/356 [76] Inventor: Oscar l). Jacobson, 1142 rimary Xaminer-William L. Freeh Woodycrest Ave., New York, N Y. Assistant ExaminerLeonard Smith Filed: June 1970 Attorney-Flame, Hartz, Sm1th & Thompson [21] App1.'No.:60,186

57 ABSTRACT Related US. Application Data 1 [62] Division Of S61. N0. 807,232, March 14, 1969, Pat. A Combination Centrifugal and viscous Shear y No. 3,643,519. pump of a disc impeller type with extremely shallow spiral grooves fabricated in both sides of the disk and [52] US. Cl 417/353, 415/90, 417/356 in close proximity to smooth stator surfaces so as to [51] lint. Cl. F041) /04, F03b 5/00 Cause a high viscous shear in a low viscosity fluid to [58] Field 011 Search 417/355, 356, 410; effect an improved pressure rise in the spiral grooves 415/90 as the disk rotates in a sense aiding in a centrifugal pumping action of the impeller disk. In operation, the [56] References Cited disk floats hydrodynamically between the stator faces UNITED STATES PATENTS and on a center journal bearing so that there are no 2 181 677 11 1939 Whittome et al. 417 356 Points during operation of the rotary Pump 3 218 981 11/1965 Kierulf 417 356 whlch Particularly adapted for use arrange l:975:568 10 1934 Dubrovin.... 415/90X for Supplying fluid P to hydmstaticany rt d b f FOREIGN PATENTS OR APPLICATIONS Suppo e eanngs o a gyroscope 1,134,967 4/ 1957 France 417/356 3 Claims, 5 Drawing Figures /Z4 44 2 0 M3 54 6 4 Z5 30 56 66 68 74 f 76 62 26 6,. ,iH g l' g; x: J. 56 94 3 5 l /Z0 51 8 a0 4.; 40 r 86 72 /7\ I 0 58 1/0 t we 25 35 704, HQ/5 VR 94 i x I22 i4 86 "T 4 56 4 7 1 9 77.. 56 .V J: 7 1:35:11 l 7-; H. 1 .5}; /Z:? i 2 k PATENTED M W 3.7810136 SHI 1 0F 4 INVENTOR.

5car Z7. Jatosan BY ATTORNEY SIEEIZBFQ v NVENTOR. 056W l7. $606500 HTTORNEY PATENTEB DECZS I973 INVENTOR. Oscar l7. Jacabsan Q TTORNEY COMBINATION CENTRIFUGAL AND VTSCUUS SHEARROTARY PUMP This is a division of application Ser. No. 807,232, filed Mar. I4, 1969, now U.S. Pat. No. 3,643,519.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention reates to afield of rotary pumps combining a centrifugal pumping action with that of a high viscous shear in a low viscosity liquid being pumped.

2. Prior Art of the Invention Heretoforc there has been provided, as disclosed in a U.S. Pat. No. 3,362,231 granted Jan. 9, 1968 to Ro land G. Baldwin et al., a pump assembly in combination with a gyroscope to provide a fluid medium under pres sure for hydrodynamically supporting the rotor and gimbal elements of a gyroscope.

1n the apparatus of the reference patent, the pump assembly effects an inward pumping action to the hydrodynamic journal bearing of the rotor member of the gyroscope and not an outward pumping action as in the present invention. Moreover, the grooves in the stator of the pumping assembly of the reference patent are inwardly diminishing or converging grooves, as distinguished from the outwardly diminishing grooves of the present invention. There is no suggestion in the cited patent of such idea of means to effect a high viscous shear in a low viscosity liquid to improve an outward centrifugal action of the pump such as that to which the pumping action of the present invention may be ap plied. Moreover, such arrangement of the present invention serves to in turn effect a high fluid pressure area concentrated over the outer periphery of the disk impeller to effect improved impeller stability in the present invention, as to which there is also no suggestion in the patent.

Moreover, in the reference patent, the pump fluid does not circulate around the armature and stator of the motor element of the pump assembly to provide effective cooling; and the pump assembly of the reference patent does not combine the desirable centrifugal and viscous numping action of the present invention.

It should be further noted that in the reference patent there would be a high viscous drag on the rotor element of the gyroscope which forms an element of the pump assembly so as to require a delicate balance between the speed of rotation of the rotor of the gyroscope and the pumping action required by the pumping assembly which is not separately operable in the reference patent from the rotor of the gyroscope, as in the case of the present invention.

There has been further noted a U.S. Pat. No. 2,954,157 granted Sept. 27, 1960 to Edwin E. Eckberg for a Molecular Vacuum Pump which embodies an impeller plate providing an inward pumping action rather than the outward pumping action of the present invention. Further, the several spiral grooves provided in the impeller plate of the reference patent are formed of a uniform width for applying a pumping action to a fluid gas rather than to an imcompressible liquid as in the present invention and in the subject patent the impeller pumping plate is neither hydrodynamically supported axially nor radially, as distinguished from the hydrodynamically supported impeller disk of the present invention.

Also, there has been noted a U.S. Pat. No. 2,104,246 granted Jan. 4, 1938 to M. A. Schwartz for a centrifugal vacuum pump in a pumping arrangement in which a liquid may be pumped from a suitable vessel by suction into a channel or passage and then discharged from the channel by the combination of a centrifugal force and the suction caused by a centrifugal flow of air.

It should be noted that in the last mentioned patent the fluid impeller disk does not provide a viscous shear action as in the present invention and there are no outward converging or diminishing grooves as in the present invention. The outwardly converging or diminishing spiral grooves of the present invention are operable to effect a distinctly different mode of operation from that of the pump of the cited patent in which there is developed a spray of extremely fine globules of the liquid for an entirely different purpose from that of the present invention.

Similarly, in a U.S. Pat. No. 1,975,568 granted Oct. 2, 1934 to John Dubrovin for a Molecular Vacuum Pump, it will be noted that the pumping impeller disk of the patent is neither operable for pumping an incompressible liquid nor hydrodynamically supported as in the present invention. In the last mentioned patent the groove in the impeller disk is of a uniform width and is not restricted outwardly as in the present invention nor is there any suggestion that there be effected a viscous shear for providing a pressure rise over the outer periphery of the disk impeller as in the present invention.

There has been further noted a U.S. Pat. No. 2,938,434 granted May 9, 1961 to Pietro Pisa for a Turbo Compressor in which a pumping action is effected upon a compressible air or gas as distinguish from a incompressible liquid of low viscosity as in the present invention. Moreover in the last mentioned patent the impeller is not hydrodynamically supported as in the present invention nor is there effected in the turbo compressor of the latter patent a viscous shear action as in the present invention.

As further distinguished from the mode of operation of the impeller disk of the present invention, in the cited patent there is effected a dual rotation of a pair of impellers in providing an inward pumping action as distinguished from the outward pumping action of the present invention.

There is no suggestion in any of the aforenoted patents of the simplified structural arrangement of the present invention in the provision of a disk impeller of a type having extremely shallow spiral grooves fabricated on both sides-of the disk and embodying the feature of a reverse groove pattern with outwardly converging or diminishing groove dimensions and a motor armature mounted on land surfaces at the outer periphcry of the disk to effect rotation of the disk impeller in very close proximity to smooth stator faces of the pump housing.

Such rotation of the disk impeller effects a pumping action which is accomplished by a combining of two effects, first the impeller acts as a centrifugal pump and second the close proximity of the disk grooves to the stator surfaces causes .a high viscous shear in the incompressible liquid being pumped.

Furthermore there is no suggestion in the cited references of any idea of means whereby the pressure rise in the outwardly converging grooves formed in the impeller disk may be effective as the disk rotates to greatly aid in a centrifugal pumping action. Also there is no suggestion in the cited references of an arrangement in which the impeller disk floates hydrodynamically between stator faces and on a center journal bearing as in the present invention so that there are effected no wear points during operation while a high pressure area is concentrated over the outer periphery of the impeller disk to improve impeller stability.

Furthermore in the cited patents there is no suggestion of the outward pumping pattern effected by the outward converging grooves formed in the impeller disk which have been discovered to provide a much better fluid pressure and flow characteristic than the conventional inwardly converging grooves, particularly as applied to the pumping of low viscosity liquids such as utilized in the present invention and having a desirable self-cleaning characteristic so that maintenance problems may be minimized in the device to which the present invention is applied.

SUMMARY OF THE INVENTION The present invention relates to a compact rotary pump mounted in an end plate of a housing of a gyroscope in which a rotatable disk impeller of a type having extremely shallow spiral grooves fabricated on both sides of the disk are arranged in a groove pattern spiralling in a reverse direction to that of the rotation of the disk and with outwardly diminishing or converging groove dimensions while a motor armature fastened to projecting land surfaces at an outer periphery of the disk is so arranged as to effectively rotate the disk in very close proximity to smooth stator faces of a pump housing.

An object of the invention is to provide by such an arrangement a pumping action accomplished by combining two effects in which, first the impeller disk acts as a centrifugal pump and second the close proximity of the disk grooves to the stator faces of the pump housing causes a high pressure shear in the low viscosity liquid medium being pumped so as to cause a rise in the pressure of the liquid medium in the spiral grooves as the disk rotates to greatly aid in the centrifugal action of the pump.

Another object of the invention is to providesuch an arrangement in which the impeller disk floats hydrodynamically between the stator faces of the pump housing and on a center journal bearing so that there are no wear points during the pumping operation.

Another object of the invention is to so provide the aforenoted arrangement in which the outward pumping pattern effected by the outward converging spiral grooves has been found to provide a much better fluid pressure and flow characteristic than in the conventional inwardly converging grooves of the impeller disks of the prior pump assemblies, particularly as applied to the pumping of low viscosity liquids to which the subject pump of the present invention is applicable so as to provide a high fluid pressure area concentrated over the outer periphery of the disk impeller to effect an improved impeller stability.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanied drawings.

DESCRIPTION OF THE DRAWINGS In the drawings in which corresponding parts have been indicated by corresponding numerals.

FIG. 1 is a side view, partly in section, of a single degree of freedom gyroscope including a combination centrifugal and viscous shear rotary pump embodying the present invention and so arranged as to provide the required fluid pressure medium and flow to hydrostatic bearing means to support a gimbal element of the gyroscope relative to the pivotal axis thereof.

FIG. 2 is a fragmentary sectional view taken along the lines 2--2 of FIG. I and looking in the direction of the arrows so as to show one side of a disk impeller of the rotary pump fabricated with shallow spiral grooves in a pattern with outwardly converging or diminishing groove dimensions and with a motor armature mounted on a projecting flange surface at an outer periphery of the disk so arranged in cooperative relation with stator poles of the motor that the impeller disk may be effectively rotated in close proximity to smooth stator faces of the pump housing in a counter clockwise or reverse direction, as indicated by the arrow, to the clockwise direction in which the spiral grooves extend.

FIG. 3 is an enlarged view ofa side surface of the impeller disk of FIG. 2 showing in greater detail the reverse groove pattern etched or fabricated therein so as to spiral in a clockwise or reverse direction from the counter clockwise direction of rotation of the impeller disk, as indicated by the arrow, and further showing that the dimensions of the spiral grooves provided in the impeller disk at the side surface thereof converge or diminish as the grooves spiral radially outward.

FIG. 4 is a diagrammatic view illustrating the improved outward pumping action effected by the spiral outward converging grooves fabricated in opposite side surfaces of the pumping impeller disk of FIGS. 1 and 2 upon the impeller disk of FIG. 3 being rotated in the counter-clock wise direction as indicated by the arrow of FIG. 3.

FIG. 5 is a graphical illustration of the area of improvement effected by the present invention in showing by the line A the fluid pressure and flow data effected by a rotary pump of a type embodying the improvements of the present invention including an impeller disk having the novel outward converging groove pattern of FIG. 3 and in which the grooves spiral in a reverse direction to the direction of rotation of the impeller disk, as indicated by the arrow of FIG. 3, as compared to the substantially lower fluid pressure and flow data indicated by the line B effected by a rotary pump of a type embodying an impeller disk including similarly dimensioned grooves, but in which the grooves are arranged in a conventional inwardly converging pattern and in which the grooves in further distinction spiral in the same direction as that of the rotation of the impeller disk; the rotary pumps in both cases being subject to like operating conditions and applying the pumping action to a like liquid medium having self-cleaning characteristics and a low viscosity of for example 0.7 centipoise, such as TRICl-ILOROTRI- FLUOROETHANE of the chemical formula CCL F-CCLF commonly marketed under the trade names of Freon Precision Cleaning Agent, Freon 113 and Genesolv D (electronic grade).

DESCRIPTION OF THE INVENTION Referring now to FIGS. 1 and 2, reference numeral 10 indicates a single degree of freedom gyroscope having a rotor element of conventional type indicated by dash line 12 and rotatably mounted about a first axis 13 in a cylindrical gimbal element 14. A cylindrical housing 16 is provided with

end plates

15 and 17 so as to define a substantially cylindrical chamber 18 in which is mounted the gimbal element 14 of the gyroscope 10. The gimbal element 14 may be angularly positioned by the gyroscopic action of the single degree of freedom gyroscope about a second axis 19-19 perpendicular to the first axis 13.

The cylindrical gimbal element 14 is positioned within the cylindrical chamber 18 in a slightly spaced relation to side wall surfaces of the cylindrical housing 16 and the end plates and 17 defining the chamber 18 so as to provide a hydrostatic bearing means for the gimbal element 14, as here in after explained.

The cylindrical gimbal element 14 further includes at opposite end portions thereof axially projecting

cylindrical shaft portions

20 and 22 having surfaces positioned in spaced relation to

surfaces defining recesses

21 and 23 formed in the

end plates

15 and 17 of the housing 16. These surfaces are so arranged in spaced relation as to cooperate in providing a hydrostatic bearing means upon which the gimbal element 14 may be angularly positioned about the longitudinal axis indicated by the reference numeral 19-19. Thus the surfaces of the

shaft portions

20 and 22 cooperate with the surfaces defining the

recesses

21 and 23 spaced apart therefrom so that a liquid medium supplied to the spaces between these surfaces form hydrodynamic bearings which support the gimbal element 14 for angular movement about the axis 19-19.

Positioned on one end portion of the housing 16 is a cylindrical casing 25 providing a chamber 27 having a fluid expansion diaphragm 28 mounted in an end of the casing 25 opposite from the housing 16. Mounted in the casing 25 and in spaced relation to the diaphragm 28 is a suitable electronic pick-off device indicated generally by the humeral 30 and which may be of a type well known in the art such as a synchro or other suitable electronic signal device having a rotor element 31 operably connected to the shaft portion 22 of the gimbal 14. The electronic pick-off device 30 is electrically connected so as to provide electrical signals in a conventional manner indicative of the angular position of the gimbal 14 effected by the gyroscope 10.

The electronic pick-off device 30 and the expansion diaphragm 28 are mounted in the cylindrical casing 25 which is in turn mounted on the one end portion of the housing 16. At an opposite end portion of the housing 16 there is mounted another cylindrical casing 34 in which there is in turn mounted a compact rotary pump 36 embodying the subject matter of the present invention.

The rotary pump 36 includes the end plate 15 so arranged as to provide a pump block sandwiched be-' tween an end of the housing 16 and an end plate 40 of the casing 34 provided at an opposite end of the cylindrical casing 34 from the housing 16. The

casings

25 and 34 have

annular flanges

42 and 44, respectively, projecting radially from the inner ends thereof and secured in position, as shown by FIG. 1, by

bolts

46 and 48 screw threadedly engaged in an annular flange 50 projecting radially from the housing 16 and intermediate the opposite ends of the housing 16. As shown by H6. 2, fastening holes 52 are provided in the flange 50 whereby the gyroscope 10 may be suitably affixed to an aircraft for operation.

The end plate 15 provides a pump block in which there is formed an annular recess 54 positioned in cooperative relation with a corresponding annular recess 56 formed in the end plate 40 of the cylindrical casing 34 so as to provide an outlet fluid pressure chamber 58 for the rotary pump 36. Further, there is formed in the end plate 15 a circular recess 60 arranged in concentric relation to the annular recess 58 and in cooperative relation with a corresponding circular recess 62 formed in the end plate 40 in concentric relation to the annular recess 56 of the end plate 40 so as to provide a fluid inlet chamber 64 for the rotary pump 36.

An outlet port 66 provided in the end plate 15 leads from the fluid pressure chamber 58 to a longitudinally extending fluid pressure channel 68 provided in the housing 16. The fluid pressure channel 68 in turn opens at

ports

70 and 72 into annular

fluid pressure channels

74 and 76, respectively, which in turn feed through a plurality of

ports

78 and 80 passing through the wall of the housing 16 and into the cylindrical chamber 18 so as to provide a fluid pressure medium about the cylindrical surface of the gimbal element 14 to provide the required pressure and flow to effect a hydrostatic bearing means between the inner surface of the housing 16 and the cylindrical surface of the gimbal element 14 positioned in spaced relation thereto so as to support the cylindrical gimbal element 14 relative to the cylindrical surface of the chamber 18 for angular movement about the axis 1919.

The fluid pressure channel 68 at an opposite end from the inlet port 66 opens into a channel 82 formed in the end plate 17 mounted in the casing 25 and positioned at the opposite end of the cylindrical housing 16 from the pump block of the end plate 15. The channel 82 in turn opens into an annular channel 84 formed in the end plate 17 so as to feed fluid pressure medium through a plurality of pressure ports 86 opening into the cylindrical chamber 18 at one end thereof to an end surface of the gimbal element 14 positioned in spaced relation to an inner surface of the end plate 17 while a plurality of pressure ports 88 are formed in the pump block of the opposite end plate 15. The pressure ports 88 open from the fluid pressure chamber 58 of the pump 36 into the cylindrical chamber 18 at the opposite end thereof and to an end surface of the gimbal element 14 positioned in spaced relation to an inner surface of the end plate 15. The

ports

86 and 88 thus provide means for applying the required fluid pressure medium and flow of the fluid medium from the pumping pressure chamber 58 to effect a hydrostatic bearing means to support the cylindrical gimbal element 14 in the cylindrical chamber 18 at the opposite end surfaces thereof.

The recess 21 formed in the pumping block of the end plate 15 opens into the fluid pressure inlet chamber 64 of the rotary pump 36 so as to provide a fluid return passage, while the recess 23 formed in the end plate 17 at the opposite end of the housing 16 provides an outlet for the fluid pressure medium from the cylindrical chamber 18 providing a hydrostatic bearing means for the shaft portion 21 of the gimbal element 14. The recess 23 in turn leads into the chamber 27 in the casing 25 carrying the electronic pick-off device 30 and the fluid expansion diaphragm 28.

There is thus provided a fluid pressure chamber 27 in the casing 25, while there is provided in the end plate 17 a fluid pressure return port 90 which opens from the chamber 27 into a longitudinally extending channel 92 formed in the housing 16. The channel 92 in turn opens into a return channel 94 formed in the pumping block of the end plate 15, while the channel 94 leads into the recess 21 formed in the pumping block of the end plate 15. Surfaces of shaft portion 20 of the cylindrical gimbal element 14 are, as heretofore explained, positioned in spaced relation to surfaces of the recess 21 in the pumping block of the end plate 15. The recess 21 in turn conducts the returning fluid medium applied through the channel 94 to the fluid inlet chamber 64 of the rotary pump 36 providing a hydrostatic bearing means for the shaft portion 20 of the gimbal element 14.

CENTRIFUGAL AND VISCOUS SHEAR ROTARY PUMP Rotatably mounted between an inner end surface 95 of the pumping block of the end plate and an inner surface 96 of the end plate 40 of the casing 34 is an impeller disk 100 having a hub portion 102 rotatably mounted in the fluid inlet chamber 64 by a stub shaft 104 projecting inwardly from the end plate 40 and concentrically positioned in relation to the hub portion 102 and the disk impeller 100. Also extending through the hub portion 102 from the opposite sides thereof are ports 106 permitting the application therethrough of the fluid pressure in the chamber 64 to thereby effect equalization of the fluid inlet pressure applied at opposite sides of the hub portion 102 in the chamber 64.

The disk impeller 100 has etched or otherwise suitably formed on opposite side surfaces thereof extremely shallow spiral grooves indicated by numeral 110 on FIGS. 2 and 3 and indicated by the dotted lines 110 on FIG. 1. Projecting land surfaces 112 at the opposite sides of the disk 110 rotated in very close proximity to the smooth stator faces of the pump housing provided by

inner surfaces

95 and 96 of the

end plates

15 and 40, respectively.

The extremely shallow spiral grooves 110 in both sides of the impeller disk 100 are formed in very close proximity to the smooth stator surfaces 95 and 96 and extend in a reverse spiral groove pattern, as shown by FIG. 3, in which the spiral grooves 110 extend radially outward in a reverse direction to that of the rotation of the impeller disk 100 indicated by the arrow of FIG. 3.

The spiral grooves 110 extend radially outward from a centrally located annular groove 115 formed in the opposite side surfaces of the disk impeller 100 about the hub 102 and stub shaft 104 in an arrangement in which each of the spiral grooves outwardly diminish in width or groove dimensions. The spiral grooves 110, as shown by the drawing of FIG. 3, are each defined by edges which tend to converge as each groove 110 extends radially outward in the side surfaces of the impeller disk 100.

There is further mounted at the outer periphery of the disk 110 an annular flange 120 on which is mounted a motor armature 122 of a suitable electric motor 123. The motor armature 122 is arranged in cooperative relation with stator poles 124 of the motor 123 secured in the pump block of the end plate 15, while positioned about the stator poles 124 are suitable motor windings 126.

Electrical energization of the windings 126 of the motor 123 by conventional means then causes rotation of the armature 122 in relation to the stator poles 124 so as to cause rotation of the impeller disk in a counter clockwise direction, as indicated by the arrow of FIGS. 2 and 3, causing the impeller disk 100 to provide an improved pumping action in which there are combined two effects. First, the impeller disk 100 acts as a centrifugal pump and second, the close proximity of the disk grooves in the opposite side surfaces of the impeller 100 to the stator surfaces 95 and 96 respectively, causes a high pressure shear in the fluid medium being pumped. This in turn cooperates with a restriction in the flow of fluid medium in the grooves 110 effected by an outwardly converging or diminishing width or dimensions of the grooves 110 to provide an improved fluid pressure rise and fluid flow characteristics as the disk 100 rotates. Such fluid pressure rise serves to greatly aid in the centrifugal action causing the fluid medium to be thrown outwardly into the annular fluid pressure chamber 58 with improved fluid pressure and flow characteristics, as shown graphically by FIG. 5, over that of an inward fluid flow pattern that may be effected by a converging groove pattern spiralling in the same direction as that of the rotation of the impeller disk.

Further, in the operation of the pump 36 the impeller disk 100 floats hydrodynamically between the stator faces 95 and 96 and on its center journal bearing 104 so that there are no resultant wear points during operation of the rotary pump 36.

The rotary pump 36 of the present invention is particularly applicable in the pumping ofa liquid indicated by numeral of a relatively low viscosity, such as TRICHLOROTRIFLUOROETHANE having the formula CCL FCCLF and commonly marketed under the trade names such as Freon Precision Cleaning Agent, Freon 113 and Genesolv D (electronic grade). The liquid 125 has a self-cleaning characteristic with a low viscosity of for example 0.7 centipoise, so that while it may be highly volatile and may vaporize readily the self-cleaning characteristics of the liquid serves to effectively minimize maintenance problems of the hydrodynamically supported bearing arrangement for the gimbal element 18 of the gyroscope 10.

The fluid system may be filled with the liquid 125, as shown by FIG. 1, by the removal of a self-sealing plug 127 so that the operator may thereby open the channel 68 to the application of the liquid 125 through a passage 129 leading into the channel 68 from a suitable source of the liquid TRICHLOROTRI- FLUOROETHANE under pressure. Upon completion of the filling operation, the self-sealing plug 127 may be repositioned in sealing relation so as to prevent loss of the liquid 125 by evaporation.

It has been discovered that in the case of such a low viscosity liquid, a rotary pump embodying an impeller disk with a conventional inward converging groove pattern in which the grooves spiral in the same direction as that of the direction of rotation of the impeller effect pumping pressures, as shown by the graphical illustration of FIG. 5, which are substantially less than that provided under like operating conditions by a rotary pump embodying an impeller disk 100 of the improved reverse spiral groove pattern of FIGS. 2 and 3 of the present invention having the outwardly converging grooves 110, as shown by FIGS. 2 and 3, spiralling in a reverse direction to that of the direction of rotation of the impeller disk 100.

9 Thus the outward pumping pattern of the improved disk 100 of FIGS. 1, 2, 3 and i, as shown graphically by FIG. 5, effects improved fluid pressure and flow characteristics when pumping low viscosity fluids such as TRICHLOROTRIFLUOROETHANE over that possible with an inward acting groove pattern operating under like conditions.

Moreover since the high pressure region in the rotary pump 36 of FIGS. 1 and 2 is at the outer periphery of the disk 100 improved impeller stability may be realized with the pump arrangement of the present invention, shown by FIGS. 1, 2, 3 and 4.

From the foregoing, it will be seen that in the present invention there has been provided a novel rotary pump 36 embodying a disk impeller 100 with reverse spiral grooves 110, as shown by FIG. 3, having outwardly converging or diminishing groove dimensions so arranged as to effect a combined outward centrifugal and viscous shear pumping effect. Moreover in the arrangement of the present invention, an increased stability in the operation of the impeller 100 results due to a concentration of a high fluid pressure area of the pump over the outer periphery of the disk impeller we and which pump arrangement is particularly advantageous in the pumping of the incompressible and relatively low viscosity liquid 125 to which the invention is particularly applicable.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear obvious to those skilled in the art, may be made without departing from-the scope of the invention.

What is claimed is:

l. A pump comprising:

a housing means;

a fluid medium within said housing means;

a pump mounted in the housing means;

a driving element of the pump rotatably mounted in the housing means;

an electrical motor means including an armature mounted around a peripheral edge of the rotatable element of the pump;

a stator element of the motor means affixed within the housing means and arranged in cooperative relation with thearmature for driving the rotatable element of the pump to supply the fluid medium under pressure;

the housing means including an internal fluid inlet pressure chamber for an impeller disk of the pump;

the means to rotatably mount the impeller disk being positioned in the fluid inlet chamber;

other fluid pressure conduit means for supplying fluid medium to the fluid inlet chamber;

the impeller disk including centrifugal means having spiral groove means provided in a side surface of the impeller disk and extending radially outward in a reverse direction to the direction of rotation of the impeller disk by the motor means so as to supply the fluid medium under centrifugal force from the fluid inlet chamber into the fluid outlet chamher;

the spiral groove means provided in the side surface of the impeller disk being of dimensions which diminish with the outward radial extension of the spiral groove means so as to restrict the flow of the fluid medium under centrifugal force;

ill

the spiral groove means in the side surface of the impeller disk being arranged in close proximity to an inner side surface of the housing means to cause a pressure shear in the fluid medium supplied under centrifugal force so as to cooperate with the restriction in the flow of the fluid medium in the spiral groove means in a sense to increase the pumping action of the impeller disk and thereby effectively improve the fluid pressure and flow characteristics of the fluid medium supplied from the fluid inlet chamber into the fluid outlet chamber upon rotation of the impeller disk by the motor means;

the fluid medium being a relatively low viscosity liquid;

the impeller disk floating hydrodynamically between inner surfaces of the housing means and the means positioned in the fluid inlet chamber to rotarably mount the impeller disk so as to prevent wear points during rotation of the impeller disk;

the internal fluid pressure outlet chamber providing a high fluid pressure area concentrated over an outer periphery of the disk impeller to effect improved impeller stability; and

the fluid medium of low viscosity liquid in the outlet chamber circulating around the stator and annular armature elements of the electric motor means to effectively cool the motor means.

2. The combination defined by claim 1 in which the fluid pressure outlet chamber includes an annular recess within the housing means extending around the periphery of the impeller disk,

the fluid inlet pressure chamber includes a circular recess in the housing means arranged in concentric relation to the annular recess of the fluid pressure outlet chamber,

the spiral groove means includes an annular groove in opposite side surfaces of the impeller disk and extending around the means to rotatably mount the impeller disk in the circular recess of the fluid inlet pressure chamber,

and spiral grooves in the opposite side surfaces of the impeller disk extending radially outward from the annular groove in a reverse direction to the direction of rotation of the impeller disk so as to supply the low viscosity liquid under centrifugal force from the annular groove,

the spiral grooves in the opposite side surfaces of the impeller disk being defined by effective edges which tend to converge with the outward radial extension of the spiral grooves so as to restrict the flow of the low viscosity liquid under centrifugal force,

and the spiral grooves in the opposite side surfaces of the impeller disk being arranged in close proximity to inner side surfaces of the housing means so as to cause a pressure shear in the low viscosity liquid supplied under centrifugal force so as to cooperate with the restriction in the flow of the low viscosity liquid in the spiral grooves in a sense to increase the pumping action of the impeller disk.

3. The combination defined by claim 2 in which the fluid medium of a low viscosity liquid consists of TRICHLOROTRIFLUOROETHANE having cleaning characteristics minimizing maintenance of the pump.

Claims

1. A pump comprising: a housing means; a fluid medium within said housing means; a pump mounted in the housing means; a driving element of the pump rotatably mounted in the housing means; an electrical motor means including an armature mounted around a peripheral edge of the rotatable element of the pump; a stator element of the motor means affixed within the housing means and arranged in cooperative relation with the armature for driving the rotatable element of the pump to supply the fluid medium under pressure; the housing means including an internal fluid inlet pressure chamber for an impeller disk of the pump; the means to rotatably mount the impeller disk being positioned in the fluid inlet chamber; other fluid pressure conduit means for supplying fluid medium to the fluid inlet chamber; the impeller disk including centrifugal means having spiral groove means provided in a side surface of the impeller disk and extending radially outward in a reverse direction to the direction of rotation of the impeller disk by the motor means so as to supply the fluid medium under centrifugal force from the fluid inlet chamber into the fluid outlet chamber; the spiral groove means provided in the side surface of the impeller disk being of dimensions which diminish with the outward radial extension of the spiral groove means so as to restrict the flow of the fluid medium under centrifugal force; the spiral groove means in the side surface of the impeller disk being arranged in close proximity to an inner side surface of the housing means to cause a pressure shear in the fluid medium supplied under centrifugal force so as to cooperate with the restriction in the flow of the fluid medium in the spiral groove means in a sense to increase the pumping action of the impEller disk and thereby effectively improve the fluid pressure and flow characteristics of the fluid medium supplied from the fluid inlet chamber into the fluid outlet chamber upon rotation of the impeller disk by the motor means; the fluid medium being a relatively low viscosity liquid; the impeller disk floating hydrodynamically between inner surfaces of the housing means and the means positioned in the fluid inlet chamber to rotarably mount the impeller disk so as to prevent wear points during rotation of the impeller disk; the internal fluid pressure outlet chamber providing a high fluid pressure area concentrated over an outer periphery of the disk impeller to effect improved impeller stability; and the fluid medium of low viscosity liquid in the outlet chamber circulating around the stator and annular armature elements of the electric motor means to effectively cool the motor means.

2. The combination defined by claim 1 in which the fluid pressure outlet chamber includes an annular recess within the housing means extending around the periphery of the impeller disk, the fluid inlet pressure chamber includes a circular recess in the housing means arranged in concentric relation to the annular recess of the fluid pressure outlet chamber, the spiral groove means includes an annular groove in opposite side surfaces of the impeller disk and extending around the means to rotatably mount the impeller disk in the circular recess of the fluid inlet pressure chamber, and spiral grooves in the opposite side surfaces of the impeller disk extending radially outward from the annular groove in a reverse direction to the direction of rotation of the impeller disk so as to supply the low viscosity liquid under centrifugal force from the annular groove, the spiral grooves in the opposite side surfaces of the impeller disk being defined by effective edges which tend to converge with the outward radial extension of the spiral grooves so as to restrict the flow of the low viscosity liquid under centrifugal force, and the spiral grooves in the opposite side surfaces of the impeller disk being arranged in close proximity to inner side surfaces of the housing means so as to cause a pressure shear in the low viscosity liquid supplied under centrifugal force so as to cooperate with the restriction in the flow of the low viscosity liquid in the spiral grooves in a sense to increase the pumping action of the impeller disk.