US3777623A - Leakage reducing arrangement for an axial piston machine - Google Patents

Leakage reducing arrangement for an axial piston machine Download PDF

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Publication number
US3777623A
US3777623A US00232478A US3777623DA US3777623A US 3777623 A US3777623 A US 3777623A US 00232478 A US00232478 A US 00232478A US 3777623D A US3777623D A US 3777623DA US 3777623 A US3777623 A US 3777623A
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United States
Prior art keywords
cylinder block
drive shaft
inlet
arrangement
face
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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
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US00232478A
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English (en)
Inventor
P Bosch
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication date
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Publication of US3777623A publication Critical patent/US3777623A/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
    • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
    • F04B1/2007—Arrangements for pressing the cylinder barrel against the valve plate, e.g. by fluid pressure

Definitions

  • ABSTRACT An arrangement for reducing in a hydraulic axial piston machine, leakage from the area between the rotary cylinder block end face, and the control face of a valve plate having inlet and outlet ports.
  • the cylinder block is mounted on the drive shaft for small axial movement, but.
  • the present invention is concerned with an improvement of axial piston machines, which may be pumps or hydraulic motors of the type provided with a rotary cylinder block which cooperates with a control surface of a valve plate, and has means for obtaining a sealed contact between the rotary cylinder block end face, and the stationary control face of the valve plate.
  • the US. Pat. No. 907,737 discloses a swash plate axial piston machine whose cylinder block is fixedly secured to the drive shaft. Pistons in the cylinders cooperate with the swash plate, and in order to obtain an axial pressure between the rotary end face of the cylinder block and the control face of the valve plate, three adjusting screws, spaced angles of 120, are provided.
  • Another object of the invention is to reduce leakage from the area between the engaging rotary end face of the cylinder block and the stationary control face of the housing.
  • Another object of the invention is to provide a fluid film between the rotary end face of the cylinder block, and the stationary control face which is sufficient to prevent extreme friction, but is too small to cause leakage.
  • the present invention provides between the cylinder block and the drive shaft, a coupling means which transmits torque between the drive shaft and the cylinder block, but has at least one guide face slanted to the axis of the drive shaft, and exerting on the cylinder block an axial force depending on the torque acting on the drive shaft, and pressing the rotary end face of the cylinder block against the stationary control face, which is preferably provided on a valve plate abutting a housing portion.
  • the' coupling includes two meshing gears having teeth slanted to the axis of the drive shaft.
  • FIGURE of the drawing is an axial sectional view of an axial piston machine provided with an arrangement according to one embodiment of the invention.
  • the pot-shaped housing part 1 of the axial piston pump is closed by a cover 3 which has, inlet and outlet means 19 and 20, opening in ports 19a and 20a on the inner surface 3a of cover 3.
  • a blind bore forming a slide bearing 5 is provided at the center of cover 3, and supports one end portion of a shaft 6 whose other end portion is mounted in a ball bearing 4 supported by the bottom wall of the housing 1.
  • a shaft portion projects out of bottom wall 1, and is driven by a motor when the machine operates as a pump.
  • Shaft 6 is provided with an annular gear portion 8 having teeth slanted to the direction of the axis of shaft 6.
  • a cylinder block 9 In the interior 2 of housing 1,3 a cylinder block 9 is located, and may be mounted on drive shaft 6 which passes through a central bore 10.
  • a spring ring 25 abuts a shoulder formed by the gear ring 8 on drive shaft 6 at one end of a spring 26, which abuts at the other end on a spring ring 27 secured to the wall of the inner bore 10 of the cylinder block 9.
  • the spring 26 urges the cylinder block 9 to move in axial direction until its rotary end face 14 abuts the stationary control surface 15 of a valve plate 16 which abuts the inner surface 3a of cover wall 3.
  • Cylinder body 9 has at the end of the central bore 10, an inner gear which has inner teeth slanted at the same angle as the teeth of the outer gear 8, and engaging the same.
  • an annular guide face 1a guides the outer cylindrical surface of cylinder block 9 and supports cylinder block 9 for axial movement.
  • the valve plate 16 is provided with two partcylindrical control ports 17 and 18 which communicate with the inlet and outlet ports 19a, 20a.
  • Axially extending cylinders 12 are provided in the cylinder block 9, and are open at one end of the cylinder block so that pistons 13 located in the cylinders 12, project out of the cylinder block.
  • Each piston 13 has a spherical head 22 mounted in a corresponding spherical recess of slide shoes 22a which slide along a circular path on a surface 24a of a stationary swash plate 24.
  • the passages 21 have ports on the rotor end face 14 located along a circle corresponding to the center circle of the part-circular ports 17 and 18 in the valve plate 16. Consequently, fluid flowing through inlet and outlet means 19, 20, inlet and outlet ports 19a, 20a, and part-circular ports 17 and 18, flows alternatingly into alternate passages 21 to the cylinders 12 whose chambers are expanded and contracted by the axial movement of the pistons 13 which depends on the slant of the swash plate 24, shown in the drawing turned an angle of 90.
  • spring 26 urges the cylinder block 9 to the left as viewed in the drawing, to a position in which the rotor end face 14 abuts the control surface 15.
  • the pressure produced by spring 26 is low, since there is no fluid pressue when the machine does not operate.
  • the axial force component may be insufficient to completely seal the control faces 14 and 15, and under such conditions, the axial pressure produced by spring 26 is sufficient to maintain the engaging control faces 14 and 15 in sliding engagement without substantial leakage.
  • the two gears have to be provided with two axially adjacent portions provided with teeth slanted in opposite direction and forming an arrow pattern on the outer gear on shaft 6 and the inner gear of cylinder block 9.
  • the angular position of the flanks of the teeth, and the play between the teeth must be selected so that during rotation in ei ther direction those tooth faces abut each other which produce an axial force in the desired direction for moving the cylinder block 9 toward the valve plate 16 and control surface 15.
  • Leakage reducing arrangement for an axial piston machine comprising housing means including bearing means defining an axis, and having inlet means and outlet means, and a control surface having inlet and outlet ports communicating with said inlet and outlet means; rotor means including a drive shaft mounted in said bearing means for rotation about said axis, a cylinder block having a plurality of cylinders open at one end of said block, a rotor end face at the other end of said cylinder block slidingly engaging said control surface, and passages connnected with said cylinders and having rotor ports on said rotor end face communicating during rotation successively with said inlet and outlet ports, means mounting said cylinder block for limited axial movement; a swash plate mounted in said housing opposite said one end of said cylinder block; piston means in said cylinders slidingly engaging said swash plate; and coupling means including a first part secured to said drive shaft and a second part secured to said cylinder block, at least one of said first and second parts having at least one guide face slanted
  • said housing means includes a housing having said inlet and outlet means, and a valve plate abutting said housing on one side thereof, and having said control surface on the other side thereof; and wherein said inlet and outlet ports are part-circular and penetrate said valve plate so as to communicate on said one side with said inlet and outlet means.
  • said cylinder block has a central bore through which said drive shaft passes; and further comprising a spring in said -central bore surrounding said drive shaft and having one end abutting said cylinder block and an other end abutting said drive shaft so that said cylinder block is biassed in axial direction to move to a position in which said rotor end face abuts said control face even if said axial force is small.
  • mounting means include a circular inner guide face portion of said housing means slidingly engaging a peripheral circular surface portion of said cylinder block located substantially in a plane transverse to said axis and passing through said coupling means.
  • At least said first part includes a set of slanted teeth disposed around said drive shaft and engaging said second part I on said cylinder block.
  • said cylinder block has a central bore through which said drive shaft passes; and wherein at least said second part includes a set of slanted inwardly projecting teeth in said central bore and engaging said first part on said drive shaft.
  • said first part is a gear having teeth slanted to said axis and radially projecting from said drivenshaft; wherein said cylinder block has a central bore through which said drive shaft passes; and wherein said second part is an inner gear within said central bore engaging said gear, the engaging teeth of said engaged gears having abutting tooth faces slanted the same angle to said axis.
  • each of said gears has first and second gear portions whose teeth are slanted in opposite directions relative to said axis, and wherein said first gear portions have teeth with lateral play on one side so as to engage when said drive shaft rotates in one direction of rotation, and said second gear portions have teeth with lateral play on the pther side so as to engage when said drive shaft rotates in the opposite direction of rotation.
  • said housing means includes a housing having said inlet and outlet means, and a valve plate abutting said housing on one side thereof, and having said control surface on the other side thereof; and wherein said inlet and outlet ports are part-circular and penetrate said valve plate so as to communicate on said one side with said inlet and outlet means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Hydraulic Motors (AREA)
US00232478A 1971-03-17 1972-03-07 Leakage reducing arrangement for an axial piston machine Expired - Lifetime US3777623A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19712112814 DE2112814A1 (de) 1971-03-17 1971-03-17 Axialkolbenmaschine

Publications (1)

Publication Number Publication Date
US3777623A true US3777623A (en) 1973-12-11

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ID=5801813

Family Applications (1)

Application Number Title Priority Date Filing Date
US00232478A Expired - Lifetime US3777623A (en) 1971-03-17 1972-03-07 Leakage reducing arrangement for an axial piston machine

Country Status (5)

Country Link
US (1) US3777623A (de)
CH (1) CH532192A (de)
DE (1) DE2112814A1 (de)
FR (1) FR2129782A5 (de)
GB (1) GB1319405A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070065320A1 (en) * 2005-09-22 2007-03-22 Graves Spray Supply, Inc. Fluid pump with enhanced seal
US20170175721A1 (en) * 2015-12-17 2017-06-22 Nabtesco Corporation Fluid pressure pump and fluid pressure system
US11460013B2 (en) * 2017-11-22 2022-10-04 Parker-Hannifin Corporation Bent axis hydraulic pump with centrifugal assist
CN116624376A (zh) * 2023-05-17 2023-08-22 启东高压油泵有限公司 一种柱塞泵的密封组件

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD245010B1 (de) * 1985-12-23 1989-06-28 Karl Marx Stadt Ind Werke Hydrostatische axialkolbenmaschine und verfahren zu deren montage

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2246018A (en) * 1940-01-15 1941-06-17 Vickers Inc Power transmission
US2608966A (en) * 1951-05-24 1952-09-02 Jack & Heintz Prec Ind Inc Hydraulic starter
US3289606A (en) * 1964-03-20 1966-12-06 Bosch Gmbh Robert Axial piston pump or motor arrangement
DE1912243A1 (de) * 1969-03-06 1970-09-17 Mannesmann Meer Ag Druckfluessigkeits-Schiefscheiben-Axialkolbenpumpen oder-motoren mit umlaufender Zylindertrommel

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2246018A (en) * 1940-01-15 1941-06-17 Vickers Inc Power transmission
US2608966A (en) * 1951-05-24 1952-09-02 Jack & Heintz Prec Ind Inc Hydraulic starter
US3289606A (en) * 1964-03-20 1966-12-06 Bosch Gmbh Robert Axial piston pump or motor arrangement
DE1912243A1 (de) * 1969-03-06 1970-09-17 Mannesmann Meer Ag Druckfluessigkeits-Schiefscheiben-Axialkolbenpumpen oder-motoren mit umlaufender Zylindertrommel

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070065320A1 (en) * 2005-09-22 2007-03-22 Graves Spray Supply, Inc. Fluid pump with enhanced seal
US7377757B2 (en) * 2005-09-22 2008-05-27 Graves Spray Supply, Inc. Fluid pump with enhanced seal
US20170175721A1 (en) * 2015-12-17 2017-06-22 Nabtesco Corporation Fluid pressure pump and fluid pressure system
US10443584B2 (en) * 2015-12-17 2019-10-15 Nabtesco Corporation Fluid pressure pump and fluid pressure system
US11460013B2 (en) * 2017-11-22 2022-10-04 Parker-Hannifin Corporation Bent axis hydraulic pump with centrifugal assist
CN116624376A (zh) * 2023-05-17 2023-08-22 启东高压油泵有限公司 一种柱塞泵的密封组件

Also Published As

Publication number Publication date
CH532192A (de) 1972-12-31
GB1319405A (en) 1973-06-06
FR2129782A5 (de) 1972-10-27
DE2112814A1 (de) 1972-09-21

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