US3750533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic pumps or motors
Assignee: Hydraulic Drive AG
•
Filing: 1969-07-07
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Granted: 1973-08-07
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Expires: 1989-07-07
Abstract
Abstract A radial piston hydraulic pump or motor comprising a rotary cylinder block receiving a number of radial pistons whose outer ends are connected to bearing pads engaging the inner surface of an annular cam ring, the pads being rectangular in end view and located in an axial direction between inwardly facing shoulders of a surrounding casing, while the rotary cylinder block is free to move axially on a central supporting shaft and is located axially through the pistons and bearing pads.
Inventors
- 👤 O Thoma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:45
CPC Classifications
F; F01; F01B; F01B1/00; F01B1/06; F01B1/0641; F01B1/0644; F01B1/0655; F01B1/0675; F01B1/0686; F01B1/0689; F01B13/00; F01B13/04; F01B13/06; F01B13/061
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
162 words
A radial piston pump or motor having a central fixed cylindrical pintle, a cylinder member or assembly mounted for rotation on said pintle and providing a number of angularly spaced generally radial cylinders, each containing a piston whose outer end is operatively connected to a bearing member, a surrounding annular cam track engaged by said bearing members, said cam track having a pair of spaced shoulders or guide surfaces at opposite axial sides thereof, and in which said cylinder member is free to move axially on said pintle, and each bearing member has a bearing surface of part-cylindrical shape coaxial with and engaging said cam track and two opposed parallel flank surfaces engaged between said pair of guide surfaces on opposite axial sides of said annular cam track, whereby each bearing member is axially located by said guide surfaces iN relation to said cam track, and said cylinder member is thereby axially located from said bearing members by means of said pistons.
Claim 2
Dependent Claim
162 words
A radial piston pump or motor having a central fixed cylindrical pintle, a cylinder member or assembly mounted for rotation on said pintle and providing a number of angularly spaced generally radial cylinders, each containing a piston whose outer end is operatively connected to a bearing member, a surrounding annular cam track engaged by said bearing members, said cam track having a pair of spaced shoulders or guide surfaces at opposite axial sides thereof, and in which said cylinder member is free to move axially on said pintle, and each bearing member has a bearing surface of part-cylindrical shape coaxial with and engaging said cam track and two opposed parallel flank surfaces engaged between said pair of guide surfaces on opposite axial sides of said annular cam track, whereby each bearing member is axially located by said guide surfaces iN relation to said cam track, and said cylinder member is thereby axially located from said bearing members by means of said pistons.
Claim 3
Dependent Claim
44 words
A pump or motor as claimed in claim 1, in which the cam track is adjustable in a direction transverse to the rotary axis of the machine to vary the volumetric capacity of the machine, but is prevented from movement in an axial direction.
Claim 4
Dependent Claim
27 words
A pump or motor as claimed in claim 1, in which the two shoulders are formed respectively on two separate parts of a casing for the machine.
Claim 5
Dependent Claim
39 words
A pump or motor as claimed in claim 1, in which each bearing member comprises a bearing slipper pivotally connected by a universal joint to the respective piston, the joint being capable of transmitting axial forces for location purposes.
Claim 6
Dependent Claim
72 words
A pump or motor according to claim 1, in which each bearing member is a sintered product, and is formed on its reverse side with an integral ball or socket, to provide a universal connection with a corresponding part on a piston, and the bearing surface is generally rectangular in development and includes a generally circular or ring-shaped oil groove, and four lands of generally triangular shape adjacent the four corners thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |