US20050226737A1 - Axial piston hydraulic power unit with pseudo slippers - Google Patents

Axial piston hydraulic power unit with pseudo slippers Download PDF

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Publication number
US20050226737A1
US20050226737A1 US10/819,883 US81988304A US2005226737A1 US 20050226737 A1 US20050226737 A1 US 20050226737A1 US 81988304 A US81988304 A US 81988304A US 2005226737 A1 US2005226737 A1 US 2005226737A1
Authority
US
United States
Prior art keywords
axial piston
slipper
piston pump
piston
pump
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.)
Abandoned
Application number
US10/819,883
Other languages
English (en)
Inventor
Michael Gandrud
Kevin Landhuis
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.)
Danfoss Power Solutions Inc
Original Assignee
Sauer Danfoss Inc
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 Sauer Danfoss Inc filed Critical Sauer Danfoss Inc
Priority to US10/819,883 priority Critical patent/US20050226737A1/en
Assigned to SAUER-DANFOSS INC. reassignment SAUER-DANFOSS INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: GANDRUD, MICHAEL D., LANDHUIS, KEVIN J.
Priority to JP2005090563A priority patent/JP2005299645A/ja
Priority to CN200510064891.8A priority patent/CN1680714A/zh
Publication of US20050226737A1 publication Critical patent/US20050226737A1/en
Abandoned legal-status Critical Current

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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
    • F04B1/122—Details or component parts, e.g. valves, sealings or lubrication means
    • F04B1/124—Pistons
    • F04B1/126—Piston shoe retaining means

Definitions

  • axial piston hydraulic pumps are known in the prior art.
  • the slipper type axial piston pump comprises a piston body with a substantially spherical ball at one end which engages a bearing of a slipper.
  • Advantages of the slipper type axial piston pump are that the pump has a long life, is robust, and very durable. Additionally, there are low contact stresses within the pump.
  • the slipper type axial piston pump has many disadvantages, including that it has many parts including a slipper hold down mechanism that consists of a number of complex parts.
  • the hydrostatic balance requires that an orifice be drilled through the piston and slipper, an operation that can be extremely expensive. This orifice causes oil to be lost in the pump thus causing reduced efficiency.
  • Slipper type pistons also have a comparatively higher mass that must reciprocate into and out of a cylinder bore with every revolution of the pump.
  • a second type of axial piston pump is a bull nose type axial piston pump.
  • a bull nose axial piston pump has a hollow piston body with a spring disposed therein to hold down the piston and the end of the piston engages race elements having a ball thrust bearing therebetween.
  • the bull nose design is very inexpensive because it does not have slippers and thus it is simple to produce.
  • the bull nose end of the piston contacts the race of the thrust bearing in a point contact. Because a high load is transferred in this point contact, high contact stresses result. High contact stresses limit the use of bull nose pistons to low power units in applications where comparatively short unit lifetime is acceptable.
  • slipper type axial piston pumps suffer from the high manufacturing costs of precision machined slippers, as well as, high manufacturing costs of the piston body.
  • Slipper type axial piston pumps also suffer from lowered efficiency due to the fluid loss that results when establishing hydrostatic oil film on which the slipper runs, as well as, rotational speed limitations that result from the high slipper mass.
  • bull nose type piston pumps are limited in pressure, displacement, and life. These practical limits prevent more wide spread use of bull nose piston pumps. Consequently, regardless of which type of piston is currently used, a manufacturer will incur disadvantages in either pump life or pump expense.
  • Yet another object of the present invention is to provide an axial piston pump that can be produced at a lower cost than a slipper type axial piston pump.
  • Another object of the present invention is to provide an anti-frictional bearing that engages race members to improve the contact stresses within an axial piston pump.
  • Still a further object of the present invention is to provide a piston pump that eliminates the need to use pressurized fluid to establish a hydrostatic film on the slipper and thereby improves efficiency.
  • Another object of the present invention is to provide a pump with slipper like features with a lower reciprocating mass.
  • the present invention is an axial piston pump that combines the technologies of a slipper type axial piston pumps and a bull nose type axial piston pumps.
  • the axial piston pump has at least one elongated hollow piston having a spring disposed within the hollow piston body creating a spring force on a pseudo slipper. Alternatively, a spring may be disposed outside the piston and creating a spring force in the same manner.
  • the pseudo-slipper is in swiveling contact with the piston body and may optionally be in further contact with an anti-frictional thrust bearing that has a first and second race element in parallel relation and a bearing therebetween. If a variable displacement piston unit is desired, an anti-frictional thrust bearing is then operably connected to the swashplate to control the angle of the swashplate.
  • FIG. 1 is sectional view of the axial piston pump of the present invention.
  • FIG. 2 is a sectional view of an axial piston pump of the present invention wherein the slipper element is a male slipper element.
  • the figures show an axial piston pump 10 of the present invention.
  • the axial piston pump 10 shows a cylinder block 12 having a piston body 14 disposed within. Additionally, piston body 14 has an elongated bore 16 disposed therethrough that may receive a spring element 18 such that the spring element 18 engages an internal wall of the body 14 at one end and a wall of the cylinder block 12 at the opposite end.
  • a ball 20 At a first end of the piston body 14 is a ball 20 that swivelably connects to a slipper element 22 that can be considered a pseudo slipper.
  • Pseudo slipper 22 engages an anti-frictional thrust bearing 24 having a first race element 26 and a second race element 28 with a bearing element 30 positioned therebetween.
  • FIG. 2 shows an alternate embodiment of FIG. 1 wherein the slipper element 22 is male.
  • the piston body 14 has a female groove 32 that receives an arcuate male slipper element 22 .
  • the spring 18 acts as a hold down force on the piston body 14 thus eliminating additional components.
  • the slipper element 22 swivels or rotates around the ball portion 20 of the piston body 14 thus causing the a distribution of the piston force on the anti-frictional thrust bearing 24 .
  • the pistons 14 continue to reciprocate into and out of their cylinder bores. In this manner, the hydraulic fluid is displaced and the hydraulic power unit acts as a hydraulic pump or a hydraulic motor.
  • the present invention seeks to approach the high performance of slipper kits while seeking a low cost level which is nearer the cost range of bull nose piston kits. Because the present invention does not require a hydrostatic balance film, as seen in slipper type axial piston kits, oil is not lost through the piston and any efficiency of the piston is not decreased. Additionally, one skilled in the art will understand that spring element 18 can be within bore 16 or optionally outside the bore 16 and still perform a hold down function.
  • the anti-frictional thrust bearing 24 additionally helps reduce contact stresses as compared to a bull nose type axial piston pump.
  • the anti-frictional thrust bearing can be any one of the group consisting of a ball bearing, a roller bearing, a tapered roller bearing, or another suitable bearing. Additionally, by eliminating the need for a hydrostatic film and thereby eliminating the oil leakage that is used to create such a film, losses are reduced and efficiency is improved. Finally, by replacing a comparatively large and massive slipper of the standard design with a pseudo-slipper of the present invention, reciprocating mass is reduced. Consequently, all of the objects of the present invention have been attained.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
US10/819,883 2004-04-07 2004-04-07 Axial piston hydraulic power unit with pseudo slippers Abandoned US20050226737A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US10/819,883 US20050226737A1 (en) 2004-04-07 2004-04-07 Axial piston hydraulic power unit with pseudo slippers
JP2005090563A JP2005299645A (ja) 2004-04-07 2005-03-28 疑似スリッパーを備える軸流ピストン液圧動力ユニット
CN200510064891.8A CN1680714A (zh) 2004-04-07 2005-04-05 具有伪滑块的轴向活塞式液压功率单元

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US10/819,883 US20050226737A1 (en) 2004-04-07 2004-04-07 Axial piston hydraulic power unit with pseudo slippers

Publications (1)

Publication Number Publication Date
US20050226737A1 true US20050226737A1 (en) 2005-10-13

Family

ID=35060724

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/819,883 Abandoned US20050226737A1 (en) 2004-04-07 2004-04-07 Axial piston hydraulic power unit with pseudo slippers

Country Status (3)

Country Link
US (1) US20050226737A1 (ko)
JP (1) JP2005299645A (ko)
CN (1) CN1680714A (ko)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102192140A (zh) * 2011-06-13 2011-09-21 宣伯民 斜盘和滑履间设滚珠装置的斜盘式轴向柱塞泵
US20140334947A1 (en) * 2013-05-10 2014-11-13 Caterpillar Inc. Fluid pump system
WO2014187547A1 (de) * 2013-05-22 2014-11-27 Hydac Drive Center Gmbh Hydropumpe und kolben für eine solche hydropumpe
US10678139B2 (en) 2003-06-09 2020-06-09 Asml Netherlands B.V. Lithographic apparatus and device manufacturing method
CN112983772A (zh) * 2021-03-30 2021-06-18 中航力源液压股份有限公司 一种降低滑履磨损的轴向柱塞泵回程装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109653974A (zh) * 2019-02-18 2019-04-19 阜新北鑫星液压有限公司 一种斜盘式柱塞泵
CN113431757B (zh) * 2021-06-25 2022-02-22 江苏可奈力机械制造有限公司 高效高速微小型液压泵

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US2392543A (en) * 1939-06-22 1946-01-08 Mercier Jean Pump
US2941475A (en) * 1957-05-24 1960-06-21 Dynex Inc Hydraulic pump
US2945444A (en) * 1957-09-23 1960-07-19 Dynex Inc Hydraulic pump
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US3009423A (en) * 1957-09-23 1961-11-21 Applied Power Ind Inc Hydraulic pump valve spacer
US3175510A (en) * 1962-10-16 1965-03-30 Amato Michael A D Variable displacement pump
USRE25850E (en) * 1965-09-07 Variable volume hydraulic pump
US3221564A (en) * 1962-01-18 1965-12-07 Hydro Kinetics Inc Piston shoe construction for axial piston pump
US3304886A (en) * 1965-11-12 1967-02-21 Borg Warner Variable displacement check valve pump
US3514223A (en) * 1968-08-19 1970-05-26 Applied Power Ind Inc Hydraulic pump
US3722370A (en) * 1970-03-31 1973-03-27 N Aplin Hydraulic wheel motor unit
US3754842A (en) * 1971-05-13 1973-08-28 Gen Motors Corp Hydraulic pump
US3951569A (en) * 1975-05-02 1976-04-20 General Motors Corporation Air conditioning compressor
US4174191A (en) * 1978-01-18 1979-11-13 Borg-Warner Corporation Variable capacity compressor
US4568252A (en) * 1980-03-07 1986-02-04 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Swash-plate type compressor
US4757795A (en) * 1986-04-21 1988-07-19 Stanadyne, Inc. Method and apparatus for regulating fuel injection timing and quantity
US4781540A (en) * 1985-12-05 1988-11-01 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Piston type compressor for air conditioning unit having asymmetric valve mechanism
US4815358A (en) * 1988-01-27 1989-03-28 General Motors Corporation Balanced variable stroke axial piston machine
US4898077A (en) * 1988-09-06 1990-02-06 Teleflex Incorporated Self-bleeding hydraulic pumping apparatus
US4936774A (en) * 1987-03-25 1990-06-26 Stoller Arnold E Orthodontic mirror image brackets to removably receive the end portions of lingual arch wires
US4976284A (en) * 1990-01-16 1990-12-11 General Motors Corporation Reed valve for piston machine
US5147190A (en) * 1991-06-19 1992-09-15 General Motors Corporation Increased efficiency valve system for a fluid pumping assembly
US5385450A (en) * 1992-10-02 1995-01-31 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Reciprocating-piston type refrigerant compressor with an improved rotary-type suction-valve mechanism
US5421243A (en) * 1994-03-21 1995-06-06 General Motors Corporation Compact refrigerant compressor
US5466130A (en) * 1994-07-26 1995-11-14 Kobelt; Jacob Helm pump
US5562182A (en) * 1993-11-24 1996-10-08 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Oil diverting unit for a refrigerant compressor
US5755562A (en) * 1996-12-13 1998-05-26 Chrysler Corporation Thrust reduction plate for an axial piston fuel pump
US5788469A (en) * 1996-12-13 1998-08-04 Chrysler Corporation Piston type liquid fuel pump with an improved outlet valve
US5836749A (en) * 1996-12-13 1998-11-17 Chrysler Corporation Piston type liquid fuel pump with an improved inlet valve
US5931644A (en) * 1995-03-30 1999-08-03 Caterpillar Inc. Precision demand axial piston pump with spring bias means for reducing cavitation
US5983781A (en) * 1996-09-06 1999-11-16 Sauer Inc. Sliding bearing with self-adjusted load bearing capacity
US6092457A (en) * 1997-08-06 2000-07-25 Kayaba Kogyo Kabushiki Kaisha Hydraulic pump or motor
US6092998A (en) * 1998-03-20 2000-07-25 Devilbiss Air Power Company Pump for a pressure washer
US6113359A (en) * 1999-06-22 2000-09-05 Eaton Corporation Axial piston pump and relieved valve plate therefor
US6142060A (en) * 1997-05-19 2000-11-07 Honda Giken Kogyo Kabushiki Kaisha High pressure fuel pump having a bellows sealing arrangement
US6217289B1 (en) * 2000-04-20 2001-04-17 The Rexroth Corporation Axial piston pump with auxiliary pump
US6220144B1 (en) * 1996-01-04 2001-04-24 Sauer Inc. Extended slipper for hydrostatic pump and motor rotating cylinders
US6338293B1 (en) * 2000-06-30 2002-01-15 Sauer-Danfoss Inc. Reduced oil volume piston assembly for a hydrostatic unit
US6352017B1 (en) * 1999-01-21 2002-03-05 Samjoo Machinery Co., Ltd. Hydraulic pump
US6368072B1 (en) * 1997-10-20 2002-04-09 Kayaba Kogyo Kabushiki Kaisha Hydraulic pump
US6786704B2 (en) * 2001-11-02 2004-09-07 Denso Corporation Compressor with single shaft support

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JPS60116082A (ja) * 1983-11-29 1985-06-22 Nippon Telegr & Teleph Corp <Ntt> 個人識別方法
US4687181A (en) * 1985-05-01 1987-08-18 Nupro Company Metering valve
US4744288A (en) * 1986-08-28 1988-05-17 Commercial Shearing, Inc. Axial piston pumps and motors
JPH07280063A (ja) * 1994-04-08 1995-10-27 Kubota Corp 油圧トランスミッション

Patent Citations (42)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE25850E (en) * 1965-09-07 Variable volume hydraulic pump
US1487965A (en) * 1921-01-05 1924-03-25 Anthony G M Michell Rotary reciprocating engine
US2392543A (en) * 1939-06-22 1946-01-08 Mercier Jean Pump
US2969810A (en) * 1955-12-27 1961-01-31 Edward C Dudley Wobble plate pump
US2941475A (en) * 1957-05-24 1960-06-21 Dynex Inc Hydraulic pump
US2945444A (en) * 1957-09-23 1960-07-19 Dynex Inc Hydraulic pump
US3009423A (en) * 1957-09-23 1961-11-21 Applied Power Ind Inc Hydraulic pump valve spacer
US3221564A (en) * 1962-01-18 1965-12-07 Hydro Kinetics Inc Piston shoe construction for axial piston pump
US3175510A (en) * 1962-10-16 1965-03-30 Amato Michael A D Variable displacement pump
US3304886A (en) * 1965-11-12 1967-02-21 Borg Warner Variable displacement check valve pump
US3514223A (en) * 1968-08-19 1970-05-26 Applied Power Ind Inc Hydraulic pump
US3722370A (en) * 1970-03-31 1973-03-27 N Aplin Hydraulic wheel motor unit
US3754842A (en) * 1971-05-13 1973-08-28 Gen Motors Corp Hydraulic pump
US3951569A (en) * 1975-05-02 1976-04-20 General Motors Corporation Air conditioning compressor
US4174191A (en) * 1978-01-18 1979-11-13 Borg-Warner Corporation Variable capacity compressor
US4568252A (en) * 1980-03-07 1986-02-04 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Swash-plate type compressor
US4781540A (en) * 1985-12-05 1988-11-01 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Piston type compressor for air conditioning unit having asymmetric valve mechanism
US4757795A (en) * 1986-04-21 1988-07-19 Stanadyne, Inc. Method and apparatus for regulating fuel injection timing and quantity
US4936774A (en) * 1987-03-25 1990-06-26 Stoller Arnold E Orthodontic mirror image brackets to removably receive the end portions of lingual arch wires
US4815358A (en) * 1988-01-27 1989-03-28 General Motors Corporation Balanced variable stroke axial piston machine
US4898077A (en) * 1988-09-06 1990-02-06 Teleflex Incorporated Self-bleeding hydraulic pumping apparatus
US4976284A (en) * 1990-01-16 1990-12-11 General Motors Corporation Reed valve for piston machine
US5147190A (en) * 1991-06-19 1992-09-15 General Motors Corporation Increased efficiency valve system for a fluid pumping assembly
US5385450A (en) * 1992-10-02 1995-01-31 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Reciprocating-piston type refrigerant compressor with an improved rotary-type suction-valve mechanism
US5562182A (en) * 1993-11-24 1996-10-08 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Oil diverting unit for a refrigerant compressor
US5421243A (en) * 1994-03-21 1995-06-06 General Motors Corporation Compact refrigerant compressor
US5466130A (en) * 1994-07-26 1995-11-14 Kobelt; Jacob Helm pump
US5931644A (en) * 1995-03-30 1999-08-03 Caterpillar Inc. Precision demand axial piston pump with spring bias means for reducing cavitation
US6220144B1 (en) * 1996-01-04 2001-04-24 Sauer Inc. Extended slipper for hydrostatic pump and motor rotating cylinders
US5983781A (en) * 1996-09-06 1999-11-16 Sauer Inc. Sliding bearing with self-adjusted load bearing capacity
US5836749A (en) * 1996-12-13 1998-11-17 Chrysler Corporation Piston type liquid fuel pump with an improved inlet valve
US5788469A (en) * 1996-12-13 1998-08-04 Chrysler Corporation Piston type liquid fuel pump with an improved outlet valve
US5755562A (en) * 1996-12-13 1998-05-26 Chrysler Corporation Thrust reduction plate for an axial piston fuel pump
US6142060A (en) * 1997-05-19 2000-11-07 Honda Giken Kogyo Kabushiki Kaisha High pressure fuel pump having a bellows sealing arrangement
US6092457A (en) * 1997-08-06 2000-07-25 Kayaba Kogyo Kabushiki Kaisha Hydraulic pump or motor
US6368072B1 (en) * 1997-10-20 2002-04-09 Kayaba Kogyo Kabushiki Kaisha Hydraulic pump
US6092998A (en) * 1998-03-20 2000-07-25 Devilbiss Air Power Company Pump for a pressure washer
US6352017B1 (en) * 1999-01-21 2002-03-05 Samjoo Machinery Co., Ltd. Hydraulic pump
US6113359A (en) * 1999-06-22 2000-09-05 Eaton Corporation Axial piston pump and relieved valve plate therefor
US6217289B1 (en) * 2000-04-20 2001-04-17 The Rexroth Corporation Axial piston pump with auxiliary pump
US6338293B1 (en) * 2000-06-30 2002-01-15 Sauer-Danfoss Inc. Reduced oil volume piston assembly for a hydrostatic unit
US6786704B2 (en) * 2001-11-02 2004-09-07 Denso Corporation Compressor with single shaft support

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10678139B2 (en) 2003-06-09 2020-06-09 Asml Netherlands B.V. Lithographic apparatus and device manufacturing method
CN102192140A (zh) * 2011-06-13 2011-09-21 宣伯民 斜盘和滑履间设滚珠装置的斜盘式轴向柱塞泵
US20140334947A1 (en) * 2013-05-10 2014-11-13 Caterpillar Inc. Fluid pump system
WO2014187547A1 (de) * 2013-05-22 2014-11-27 Hydac Drive Center Gmbh Hydropumpe und kolben für eine solche hydropumpe
AU2014270773B2 (en) * 2013-05-22 2017-12-21 Hydac Drive Center Gmbh Hydraulic pump and piston for such a hydraulic pump
US9849482B2 (en) 2013-05-22 2017-12-26 Hydac Drive Center Gmbh Hydraulic pump and piston for such a hydraulic pump
CN112983772A (zh) * 2021-03-30 2021-06-18 中航力源液压股份有限公司 一种降低滑履磨损的轴向柱塞泵回程装置

Also Published As

Publication number Publication date
CN1680714A (zh) 2005-10-12
JP2005299645A (ja) 2005-10-27

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AS Assignment

Owner name: SAUER-DANFOSS INC., IOWA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GANDRUD, MICHAEL D.;LANDHUIS, KEVIN J.;REEL/FRAME:015525/0838

Effective date: 20040406

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION