US3827835A - Low speed rotary fluid apparatus with elastic sealing liner - Google Patents

Low speed rotary fluid apparatus with elastic sealing liner Download PDF

Info

Publication number
US3827835A
US3827835A US00310267A US31026772A US3827835A US 3827835 A US3827835 A US 3827835A US 00310267 A US00310267 A US 00310267A US 31026772 A US31026772 A US 31026772A US 3827835 A US3827835 A US 3827835A
Authority
US
United States
Prior art keywords
rotor
sealing member
low speed
fluid apparatus
peripheral surface
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 - Lifetime
Application number
US00310267A
Other languages
English (en)
Inventor
Y Higuchi
Y Mitsumura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CKD Corp
Original Assignee
Chukyo Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Chukyo Electric Co Ltd filed Critical Chukyo Electric Co Ltd
Application granted granted Critical
Publication of US3827835A publication Critical patent/US3827835A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
    • F01C21/08—Rotary pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C1/00—Rotary-piston machines or engines
    • F01C1/22—Rotary-piston machines or engines of internal-axis type with equidirectional movement of co-operating members at the points of engagement, or with one of the co-operating members being stationary, the inner member having more teeth or tooth- equivalents than the outer member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C19/00—Sealing arrangements in rotary-piston machines or engines
    • F01C19/10—Sealings for working fluids between radially and axially movable parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2240/00—Components
    • F04C2240/80—Other components
    • F04C2240/802—Liners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2225/00—Synthetic polymers, e.g. plastics; Rubber
    • F05C2225/04—PTFE [PolyTetraFluorEthylene]

Definitions

  • ABSTRACT In a fluid apparatus for low speed continuous rotation having a rotor rotatable continuously within a cylinder, a tubular seal material of synthetic resin such, for example, as fluoric resin is fitted into the cylinder in contact with the inner periphery of the cylinder, the seal material is compressed axially by a pair of end covers closing the ends of the cylinder, and the movable rotor is provided with a square packing in contact with the inner peripheral surface of the seal material and the inner surfaces of the end covers. The seal material and the square packing cooperate with each other toprovide complete sealing at corners of the contact surface within the cylinder preventing internal leakage of fluid within the cylinder.
  • the present invention relates to a fluid apparatus for low speed continuous rotation, and more particularly,
  • a fluid apparatus for low speed continuous rotation for continuously rotating a rotor within a cylinder or for delivering fluid by rotation of the rotor.
  • a complete sealing between the rotor and the cylinder is needed since no leakage of the fluid is permitted.
  • the sealing apparatus of prior arts it has been impossible to provide a complete sealing between the rotor and the cylinder. Accordingly, the technical idea to adopt a mechanism for applying fluid pressure directly to the rotor in a fluid apparatus such as pump or motor has been kept out of the actual use. Therefore, the fluid apparatus of prior arts has such disadvantages that the construction is very complicated and the torque produced by such apparatus is very small.
  • the primary object of the present invention is to provide a fluid apparatus for low speed continuous rotation having a sealing apparatus capable of preventing almost completely the leakage between the rotor and the inner surface of the cylinder even when a fluid pressure is applied directly to the rotor.
  • Another object of the present invention is to provide a fluid apparatus for low speed continuous rotation which is simple in construction, easy to manufacture and has a very high sealing property.
  • the fluid apparatus for low speed continuous rotation is formed by providing a tubular seal material of synthetic resin in contact with the inner peripheral surface of the cylinder and compressing the sealing material in the axial direction by end covers closing the ends of the cylinder.
  • FIG. 1 is a side sectional view of a fluid apparatus for low speed continuous rotation according to the present invention
  • FIG. 2 is a front view of the apparatus with the end cover at right side (FIG. 1) removed;
  • FIG. 3 is a sectional view taken along the line III-III of FIG. 1 and seen from the direction of arrows;
  • FIG. 4 is a sectional view taken along the line IV-IV of FIG. 1 and seen from the direction of arrows;
  • FIG. 5 is a sectional view taken along the line V-V of FIG. 2;
  • FIG. 6 is a fragmentary enlarged sectional view of FIG. 5 showing the corner formed by the seal material, square packing and end cover.
  • FIGS. 1 3 there is shown a fluid apparatus for low speed continuous rotation according to the present invention generally designated 1 having a casing 2, a shaft means 4, and a rotor 5.
  • a tubular cylinder body 20 of the casing 2 has an inner peripheral surface 21 formed by a two-joint trochoidally curved surface.
  • end covers 22 and 23 At both ends of the cylinder body there are respectively fixed end covers 22 and 23 by suitable means such as bolts (not shown).
  • a stepped bearing hole 24 for receiving a shaft to be hereinafter described, and at the circumference of the bearing hole there are formed mutually spaced annular grooves 25 and 26 which are communicated respectively with an inlet port 27 and an outlet port 28 provided at the end cover 22 as shown in FIG. 4.
  • an opening 29 at the position corresponding to the bearing hole 24 of the end cover 22, and within the opening there is fitted a bearing support 30 having a stepped bearing hole 31 at the center thereof.
  • the bearing support 30 is fixed to the end cover 23 by suitable means such as bolts (not shown).
  • An end (the right end in FIG. 1) of the bearing support 30 protrudes axially within a cylinder chamber A by the predetermined length and on the outer peripheral surface of the protruded end is formed a gear 32.
  • the sealing member 34 which is a little longer than the cylinder itself is beforehand worked precisely so that the angle fonned by the inner peripheral surface 35 and the end faces 36a, 36b is accurately right-angled and that the edge is not made round, and, as a result, when the end covers 22 and 23 are fixed to the cylinder body 20, the sealing member 34 is compressed in the axial direction and the corner formed by the inner peripheral surface 35 of the sealing member 34 and the inner surface of the end cover is not made round.
  • the shaft means 4 comprises an eccentric shaft wherein the axis of journal portions 40 and 41 and the axis of a rotor support 42 provided between the journal portions 40 and 41 are not co-axial.
  • the eccentric shaft is supported rotatably with respect to the casing by bearings 38 and 39 fitted respectively into larger diameter hole portions 24a and 31a of the bearing holes of the end covers 22 and the bearing support 30.
  • a pair of fluid passages 45a and 45b extending axially which are respectively at an end communicated to the grooves 43a and 43b respectively through passages 46a and 46b.
  • the other ends of the passages 45a and 45b are sealed respectively by plugs 47a and 47b.
  • the passage 45a is communicatable with the outer periphery of the journal, namely the annular groove 25 through an axially extending passage 48a provided at the position corresponding to the annular groove 25 provided at the end cover 22, and similarly, the passage 45b is communicatable with the outer periphery of the journal, namely the annular groove 26 through an axially extending passage 48b provided at the position corresponding to the annular groove 26 formed at the end cover 22.
  • a sleeve 51 of the rotor 5 rotatably by and with respect to the eccentric shaft 4.
  • the inner diameter of the rotor sleeve 51 is larger at the bearing support side and on the inner peripheral surface thereof there is provided an internal gear 52 for meshing with a gear 32 provided at the bearing support 30.
  • a cylindrical sealing member 53 of elastic synthetic resin such, for example, as urethane rubber or fluoric resin.
  • a rotor member 54 the section of which is substantially a triangle.
  • the rotor member 54 is divided into three portions 54a, 54b, and 540 at each vertices.
  • the rotor portions 54a, 54b, and 540 are provided at each one of the joint surfaces respectively with rectangular projections 55a, 55b, and 550 as shown in FIGS. 3 and 5, and on the outer peripheries of the projections there are respectively fitted square packings 56a, 56b, and 560.
  • the rotor portions 54a, 54b, and 54c are joined respectively with the adjacent rotor portions by a plurality of pins 57 and further with the rotor sleeve by a plurality of pins 58.
  • the rotor 5 has such a construction that at each vertex the square packings 56a, 56b, and 560 are always in contact with the inner surface 35 of the sealing member within the cylinder. Accordingly, the rotor is supported on the eccentric shaft 4 rotatably with respect thereto within the cylinder chamber A so that the rotor sleeve 51 and the rotor member 54 are in one unit and the square packings 56a, 56b, and 56c are always in contact with the inner surface 35 of the sealing member and the inner surface of the end cover.
  • feeding and exhaust of fluid to and from the cylinder chamber portion a defined by the rotor portion 54c, square packings 56b, 56c, sealing member 34, and end covers 22, 23 is made through the passage port 59c
  • feeding and exhaust of fluid to and from the cylinder chamber portion a" defined by the rotor portion 54a, square packings 566, 56a, sealing member 34, and end covers 22, 23 is made through the passage port 59a
  • feeding and exhaust of fluid to and from the cylinder chamber portion a' defined by the rotor portion 54b, square packings 56a, 56b, sealing member 34, and the end covers 22, 23 is made through the passage port 59b.
  • the fluid flowing in from the inlet port 27 is directed through the annular groove 25, passage 48a, passage 45a and passage 46a into the groove 43a formed on the outer periphery of the eccentric shaft, and then introduced into the cylinder chamber portion a through the passage 590.
  • the fluid introduced into the cylinder chamber portion a acts on the outer surface of the rotor portion 540 to rotate the rotor in the clockwise direction on the eccentric shaft keeping the rotor in contact with the inner surface of the sealing member 34 and to rotate the eccentric shaft 4 in the clockwise direction.
  • the fluid within the cylinder chamber portion a" is discharged outside from the outlet port 28 through the passage port 59a, groove 43b, passage 46h, passage 45h, passage 48b, and annular groove 26.
  • the rotor 5 takes the position shown in broken line in FIG. 2.
  • the groove 43a communicated with the inlet port 27 is communicated with the cylinder chamber portion a" through the passage port 490, the fluid flows into the cylinder chamber portion a" to act on the outer surface of the rotor portion 54a and to rotate the rotor in the clockwise direction.
  • the fluid within the cylinder chamber portion a' is discharged from the outlet port 28 through the passage port 59b, groove 43b, passage 46b, passage 45b, passage 48b, and annular groove 26.
  • the passage port 59c is closed by the projection 44b, the fluid within the cylinder chamber portion a remains there without being discharged until the passage port 59c is again communicated with the groove 46b.
  • the rotor and the eccentric shaft continue rotation in the proportion of three turns of the eccentric shaft per one turn of the rotor.
  • the tubular sealing member 34 and the cylindrical sealing member 53 are, as described above, made of synthetic resin having high elasticity and superior sealing property, and the both end faces thereof are precisely worked so that the edge portions formed by the end portions and the inner peripheral surface or the outer peripheral surface will not be made round.
  • the both end covers are polish-finished in the inner surface, and by these polish-finished inner surface the sealing members 34 and 53 are slightly compressed in the axial direction and assembled.
  • the inner surface 35 of the sealing member 34, the outer surface of the sealing member 53, and the inner surfaces of the end covers 22 and 23 are polish-finished in the same degree of the slide contact surface with O-ring commonly used taking the surface roughness into consideration.
  • the square packings 56a, 56b, and 56c fitted into the projections of the rotor member are made of elastic material such, for example, as synthetic resin and serve to prevent leakage between these square packings and the inner surface of the sealing member 34, the inner surface of the end covers, and the outer surface of the sealing member 53.
  • elastic material such, for example, as synthetic resin
  • the clearance at the corner may be about 0.004 mm when such packings are used.
  • the clearance can be further reduced as small as the surface roughness of the cylindrical surface 3.2S(JlS)'. Accordingly, the corner portion can 'be sealed in the same degree as in the other portion.
  • the packings may not necessarily be square packings. Since the sealing members 34 and 53 are made of elastic material and compressed in the axial direction, even when the angle formed by the end covers 22, 23 and the inner or outer peripheral surfaces of the sealing members 34 and 53 is not precisely in a right angle, the sealing members can provide sufficient sealing effect in the normal direction to thereby enable smooth rotation of the rotor.
  • the point of the square packing in contact with the sealing member 34 is oscillated (oscillation angle
  • the oscillation can be eliminated by suitable selection of the shape of the outer peripheries of the square packings, hardness of the material, and the rotating back-up ring.
  • tubular sealing member may have section in any annular shape and not limited to the two-joint trochoidal curve type.
  • a fluid apparatus for low speed continuous rotation comprising in combination:
  • a casing having a tubular cylinder body and a pair of end covers for closing both ends of the cylinder body;
  • said fluid apparatus being provided with a tubular sealing member of elastic synthetic resin fitted onto the inner peripheral surface of the cylinder and packings fitted to said rotor and being in sealing contact with the inner peripheral surface of the sealing member and the inner surfaces of the end covers;
  • tubular sealing member having the length a little larger than that of the cylinder body and being made so that the edge portion formed by the both end faces and the inner peripheral surface is not made round, whereby, when assembled, the sealing member is compressed in the axial direction by the pair of end covers.
  • packings comprises square packings and is in sealing contact with the outer peripheral surface of the cylindrical sealing member fitted between the rotor sleeve and the rotor member.
  • said rotor has a rotor sleeve and a rotor member; said fluid apparatus is provided with a cylindrical sealing member of elastic synthetic resin fitted between the rotor sleeve and the rotor member; said cylindrical sealing member has the length a little larger than that of the cylinder body and is made so that the edge portion formed by the both end faces and the outer peripheral surface is not made round, whereby, when assembled, the cylindrical sealing member is compressed in the axial direction by the pair of end covers. 4.
  • a fluid apparatus for low speed continuous rotation according to claim 1, wherein:
  • the inner peripheral surface of the cylinder body is formed by a two-jointed trochoidally curved surface; said rotor has a substantially triangular section;
  • a fluid apparatus for low speed continuous rotation according to claim 4, wherein:
  • said shaft means comprises an eccentric shaft; and, said rotor is rotatable with respect to the eccentric shaft.
  • said rotor member is divided into three portions at the vertices of said triangle; and, said packings are fitted between the joint portions of the divided rotor.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Hydraulic Motors (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Rotary Pumps (AREA)
  • Compressor (AREA)
US00310267A 1971-12-03 1972-11-29 Low speed rotary fluid apparatus with elastic sealing liner Expired - Lifetime US3827835A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP46097186A JPS5218402B2 (de) 1971-12-03 1971-12-03

Publications (1)

Publication Number Publication Date
US3827835A true US3827835A (en) 1974-08-06

Family

ID=14185536

Family Applications (1)

Application Number Title Priority Date Filing Date
US00310267A Expired - Lifetime US3827835A (en) 1971-12-03 1972-11-29 Low speed rotary fluid apparatus with elastic sealing liner

Country Status (3)

Country Link
US (1) US3827835A (de)
JP (1) JPS5218402B2 (de)
DE (1) DE2258712C3 (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3930767A (en) * 1974-07-16 1976-01-06 General Motors Corporation Circular rotor side seal for rotary machines
US4028021A (en) * 1975-12-08 1977-06-07 Curtiss-Wright Corporation Rotary trochoidal compressor with compressible sealing
US4090825A (en) * 1975-02-07 1978-05-23 Rylewski Eugeniusz Plate with passages for fluid rotative machines
US6402488B2 (en) * 2000-01-31 2002-06-11 Sumitomo Electric Industries, Ltd. Oil pump
US6619938B2 (en) * 2000-01-13 2003-09-16 Keith F. Woodruff Flexible vane pump
US20140186204A1 (en) * 2011-07-07 2014-07-03 Avl List Gmbh Rotary piston engine including a piston assembly, vehicle including the rotary piston engine and a manufacturing method for the piston assembly
US20180371908A1 (en) * 2016-02-14 2018-12-27 Weilun Chen Paired air pressure energy power system and power method thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0262189B1 (de) * 1986-04-01 1990-05-30 Jean Malfit Hydraulischer hochdruckerzeuger bzw.-empfänger zur leistungsübertragung
DE3863845D1 (de) * 1987-05-26 1991-08-29 Wankel Gmbh Schmiersystem fuer das exzenterlager einer rotationskolbenbrennkraftmaschine.
AU635867B2 (en) * 1990-10-22 1993-04-01 Hitachi Automotive Engineering Co., Ltd. Centrifugal fan with noise suppressing arrangement
JP2846167B2 (ja) * 1991-10-09 1999-01-13 株式会社日立製作所 遠心送風機，自動車用空気調和装置の送風機及び遠心送風機を備えた自動車用空気調和装置
WO2022248638A1 (de) 2021-05-17 2022-12-01 Felix Wirz Innenachs-kreiskolbenvorrichtung
CH718635A1 (de) * 2021-05-17 2022-11-30 Wirz Felix Wasserkraft-Entspannungsmaschine zur Stromerzeugung.

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2966860A (en) * 1957-04-03 1961-01-03 Lobee Pump & Machinery Co Pump for corrosive fluids
US3155313A (en) * 1962-10-01 1964-11-03 Cuertiss Wright Corp Rotor housing construction of rotating combustion engine
US3190183A (en) * 1962-05-10 1965-06-22 Cooper Bessemer Corp Air tool improvement
US3193188A (en) * 1963-04-11 1965-07-06 Curtiss Wright Corp Rotor and seal construction for rotary mechanisms
US3251541A (en) * 1963-12-20 1966-05-17 Nsu Motorenwerke Ag Sealing construction for rotary mechanisms
US3270717A (en) * 1960-10-13 1966-09-06 Daimler Benz Ag Rotary-piston internal combustion engine of trochoidal construction
US3359951A (en) * 1964-11-05 1967-12-26 Sabet Huschang Sealing device
DE1426016A1 (de) * 1960-08-22 1968-12-12 Paul Jaehrling Verbrennungsmotor

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2966860A (en) * 1957-04-03 1961-01-03 Lobee Pump & Machinery Co Pump for corrosive fluids
DE1426016A1 (de) * 1960-08-22 1968-12-12 Paul Jaehrling Verbrennungsmotor
US3270717A (en) * 1960-10-13 1966-09-06 Daimler Benz Ag Rotary-piston internal combustion engine of trochoidal construction
US3190183A (en) * 1962-05-10 1965-06-22 Cooper Bessemer Corp Air tool improvement
US3155313A (en) * 1962-10-01 1964-11-03 Cuertiss Wright Corp Rotor housing construction of rotating combustion engine
US3193188A (en) * 1963-04-11 1965-07-06 Curtiss Wright Corp Rotor and seal construction for rotary mechanisms
US3251541A (en) * 1963-12-20 1966-05-17 Nsu Motorenwerke Ag Sealing construction for rotary mechanisms
US3359951A (en) * 1964-11-05 1967-12-26 Sabet Huschang Sealing device

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3930767A (en) * 1974-07-16 1976-01-06 General Motors Corporation Circular rotor side seal for rotary machines
US4090825A (en) * 1975-02-07 1978-05-23 Rylewski Eugeniusz Plate with passages for fluid rotative machines
US4028021A (en) * 1975-12-08 1977-06-07 Curtiss-Wright Corporation Rotary trochoidal compressor with compressible sealing
US6619938B2 (en) * 2000-01-13 2003-09-16 Keith F. Woodruff Flexible vane pump
US6402488B2 (en) * 2000-01-31 2002-06-11 Sumitomo Electric Industries, Ltd. Oil pump
US20140186204A1 (en) * 2011-07-07 2014-07-03 Avl List Gmbh Rotary piston engine including a piston assembly, vehicle including the rotary piston engine and a manufacturing method for the piston assembly
US9441485B2 (en) * 2011-07-07 2016-09-13 Avl List Gmbh Rotary piston engine including a piston assembly, vehicle including the rotary piston engine and a manufacturing method for the piston assembly
US20180371908A1 (en) * 2016-02-14 2018-12-27 Weilun Chen Paired air pressure energy power system and power method thereof
US10738613B2 (en) * 2016-02-14 2020-08-11 Weilun Chen Paired air pressure energy power system and power method thereof

Also Published As

Publication number Publication date
DE2258712B2 (de) 1975-01-23
DE2258712A1 (de) 1973-06-07
DE2258712C3 (de) 1975-08-28
JPS4863305A (de) 1973-09-03
JPS5218402B2 (de) 1977-05-21

Similar Documents

Publication Publication Date Title
US4018548A (en) Rotary trochoidal compressor
US3560119A (en) Fluid pump or motor
US4087215A (en) Gerotor gearset device
US3289602A (en) Fluid pressure device
US3539281A (en) Sliding-vane rotary fluid displacement machine
US3285189A (en) Motor, pump or compressor with a piston rotatable within a housing
US4747762A (en) Fluid machine
JP2624979B2 (ja) 圧縮可能な作動流体用容積型回転機械
HU210369B (en) Machine with rotating blades
US3846051A (en) Valving arrangement in a hydraulic device
GB1236400A (en) Hydraulic rotary motors and pumps
US3873253A (en) Vane seal means in rotary vane machines
JPS59231269A (ja) メカニカルシ−ル
US5624248A (en) Gerotor motor and improved balancing plate seal therefor
EP0049881B1 (de) Spiralfluidverdrängeranlage mit einer Einrichtung zur Verdichtungsabänderung
US4545748A (en) Compact high torque hydraulic motors
US3277833A (en) Hydraulic device
US3563678A (en) Pumps
US3909165A (en) Geared hydraulic apparatus
US2985110A (en) Pump construction
US3188969A (en) Hydraulic pump or motor
US3871798A (en) Rotary and orbiting piston machine with internal shaft
US3302584A (en) Valving arrangement for fluid pressure device
US3563679A (en) Pressure-compensated gear-rotor hydraulic motor or pump
US3591321A (en) Valving in combination with fluid pressure operating means