US3747476A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Balanced hydraulic device
Assignee: HARTMANN CONTROLS Inc C/O ROCKFORD AUTOMATION Inc 3381 FOREST VIEW ROAD ROCKFORD IL 61109 A CORP OF WI
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Filing: 1972-04-04
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Granted: 1973-07-24
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Expires: 1992-04-04
Abstract
Abstract In an axial piston hydraulic device, having an angularly tiltable tilt plate for controlling the stroke of the pistons, the cylinders in the rotor communicate with the high and low pressure ports of the device by way of passages which are positioned between the axes of the cylinders and the rotational axis of the rotor to reduce resistances to fluid flow resulting from rotor rotation when the cylinders are on their low pressure stroke. Additional passages are provided which communicate the high pressure port with the rotor and/or the bearing of the tilt plate to exert counterbalancing forces on these components during operation of the device. On and off-stroke control pistons may also be positioned on the side of the tilt plate opposite the pistons to exert counterbalancing forces on the tilt plate.
Inventors
- 👤 J Ankeny
- 👤 H Foddy
- 👤 D Kessler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:06
CPC Classifications
F; F01; F01B; F01B3/00; F01B3/0032; F01B3/0044; F01B3/007; F01B3/0052; F01B3/0055; F01B3/10; F01B3/103; F01B3/106; F04; F04B; F04B49/00; F04B49/08
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
102 words
In a fluid pressure device having high and low pressure ports, a rotor in which pistons are reciprocal therein, a tilt plate mounted for pivoting on bearing means whereby the stroke of the pistons may be varied, means communicating said bearing means with a sorce of fluid under pressure for exerting a force on said tilt plate adjacent said bearing means in a direction opposite to the force exerted by said pistons on said tilt plate, and meanS for relieving fluid from said high pressure port through said bearing means when the pressure of said last mentioned fluid exceeds a predetermined amount.
Claim 2
Dependent Claim
102 words
In a fluid pressure device having high and low pressure ports, a rotor in which pistons are reciprocal therein, a tilt plate mounted for pivoting on bearing means whereby the stroke of the pistons may be varied, means communicating said bearing means with a sorce of fluid under pressure for exerting a force on said tilt plate adjacent said bearing means in a direction opposite to the force exerted by said pistons on said tilt plate, and meanS for relieving fluid from said high pressure port through said bearing means when the pressure of said last mentioned fluid exceeds a predetermined amount.
Claim 3
Dependent Claim
22 words
In the device of claim 1 wherein said communicating means coMmunicates said bearing means with the high pressure port of the device.
Claim 4
Dependent Claim
22 words
In the device of claim 1 wherein said bearing means is positioned on the side of said tilt plate opposite said pistons.
Claim 5
Dependent Claim
94 words
In the device of claim 1 wherein said bearing means comprises a first block means stationarily mounted in the device and having an arcuate surface facing said tilt plate, a member positioned on and movable with said tilt plate and having an arcuate surface complimenting the arcuate surface of said block means, and passage means communicating the high pressure port with the arcuate surface of said block means, whereby fluid at high pressur is introduced between said arcuate surfaces and exerts a force on the arcuate surface of said member toward said tilt plate.
Claim 6
Dependent Claim
34 words
In the device of claim 4, wherein said arcuate surfaces are positioned on the side of said tilt plate opposite said pistons and said force is exerted on said opposite side toward said pistons.
Claim 7
Dependent Claim
53 words
In the device of claim 4, wherein said bearing means includes arcuate insert means between said arcuate surfaces, said insert means having a grooved surface facing the arcuate surface of said block means, and said passage means extends through said block means to introduce said high pressure fluid between the last mentioned surfaces.
Claim 8
Dependent Claim
26 words
In the device of claim 4, wherein said passage means continuously introduce said high pressure fluid to said bearing means while said device is in operation.
Claim 9
Dependent Claim
72 words
In the device of claim 1 wherein said means for relieving the fluid in said high pressure port includes control piston means for tilting said tilt plate and exerting a force on said tilt plate in the same direction as the force exerted on said tilt plate by said bearing means, the force exerted by said control piston means separating said bearing means to relieve said fluid in said high pressure port.
Claim 10
Dependent Claim
183 words
In a fluid pressure device having high and low pressure fluid ports, a rotor mounted for rotation, a plurality of cylinders in the rotor alternately communicating with said ports, a plurality of pistons reciprocally movable in said cylinders, a tilt plate one side of which is drivingly associated with an end of said pistons, said tilt plate being mounted for rotation about a pivot axis adjacent one end of the rotor whereby the stroke of the pistons may be varied, control means for selectively exerting a force on the tilt plate to pivot the tilt plate about is pivot axis, said control means exerting a first force on said tilt plate in a direction opposite the force exerted on said tilt plate by said pisotns, bearing means pivotally mounting said tilt plate for said rotation, and means communicating said bearing means with said high pressure port for exerting a second force on said tilt plate in a direction opposite to the force exerted by said pistons on said tilt plate, said first and second forces together counterbalancing the forces exerted by said pistons.
Claim 11
Dependent Claim
183 words
In a fluid pressure device having high and low pressure fluid ports, a rotor mounted for rotation, a plurality of cylinders in the rotor alternately communicating with said ports, a plurality of pistons reciprocally movable in said cylinders, a tilt plate one side of which is drivingly associated with an end of said pistons, said tilt plate being mounted for rotation about a pivot axis adjacent one end of the rotor whereby the stroke of the pistons may be varied, control means for selectively exerting a force on the tilt plate to pivot the tilt plate about is pivot axis, said control means exerting a first force on said tilt plate in a direction opposite the force exerted on said tilt plate by said pisotns, bearing means pivotally mounting said tilt plate for said rotation, and means communicating said bearing means with said high pressure port for exerting a second force on said tilt plate in a direction opposite to the force exerted by said pistons on said tilt plate, said first and second forces together counterbalancing the forces exerted by said pistons.
Claim 12
Dependent Claim
22 words
In the device of claim 9 wherein said control means relieves excessive pressures in said high pressure port through said bearing means.
Claim 13
Dependent Claim
24 words
In the device of claim 9 wherein said control means is hydraulically operated by the fluid in the high pressure port of said device.
Claim 14
Dependent Claim
51 words
In the device of claim 9 wherein said control means comprises first and second hydraulic pistons, said first piston being positioned to exert a force on said tilt plate which increases its tilt and said second piston being positioned to exert a force on said tilt plate which decreses the tilt.
Claim 15
Dependent Claim
39 words
In the device of claim 12 wherein said control means include means which is operable independently of the pressure of the hydraulic fluid of said device to exert a force on the tilt plate to fully tilt said plate.
Claim 16
Dependent Claim
16 words
In the device of claim 13 wherein said last mentioned means comprises a spring urged piston.
Claim 17
Dependent Claim
20 words
In the device of claim 12 including means to connect said pistons with the high pressure port of said device.
Claim 18
Dependent Claim
43 words
In the device of claim 12 including compensator means for selectively varying said first and second pistons, said compensator means continuously communicating a source of pressure fluid with said first piston and selectively communicating a source of pressure fluid with said second piston.
Claim 19
Dependent Claim
20 words
In the device of claim 16 wherein said sources of pressure fluid are the high pressure port of the device.
Claim 20
Dependent Claim
23 words
In the device of claim 16 wherein said compensator means includes a spool valve for selectively communicating said source with said second piston.
Claim 21
Dependent Claim
27 words
In the device of claim 16 wherein said compensator means includes relief means for relieving said second piston when the pressure in said high pressure port decreases.
References Cited (Backward Citations)
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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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |