Patent US3896912A successfully refreshed from Google Patents.
US3896912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrostatic clutch
Assignee: Moog GAT GmbH
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Filing: 1974-05-17
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Granted: 1975-07-29
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Expires: 1994-05-17
Abstract
Abstract A clutch connecting an input shaft to a coaxial output shaft includes a rotary, gear-type pump whose casing is fixedly mounted on the input shaft while the output shaft carries the driven gear of the pump. A valve in the pumping circuit between the intake and discharge ports of the casing engages the clutch in the closed position. A cooling pump driven by one of the shafts drives cooled oil through the casing, and the resulting heat transfer between the cooled oil and the oil circulated by the gear pump maintains high viscosity in the oil in the gear casing and prevents oil leakage and resulting slipping of the engaged clutch. Transmission of residual torque between the shafts when the clutch is disengaged by opening the valve can be reduced or eliminated by blocking the circuit of the cooling pump.
Inventors
- 👤 Ivan Jaroslav Cyphelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:17
CPC Classifications
F; F16; F16D; F16D31/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
214 words
A hydrostatic clutch comprising: a. an input shaft; b. an output shaft; c. a positive displacement pump including a casing element having a cavity, an intake port and a discharge port communicating with said cavity, and a pumping element movable in said cavity, 1. said elements being connected to said shafts respectively for pumping a fluid from said intake port to said discharge port when one of said shafts rotates at a speed different from the speed of rotation of the other shaft; d. conduit means constituting a pumping circuit connecting said ports; e. valve means in said circuit; f. a body of liquid in said circuit and in said casing element; g. actuating means for moving said valve means between a first position in which said valve means blocks said circuit, whereby said clutch is engaged for transmitting torque between said shafts, and a second posiTion in which said liquid is free to be pumped through said circuit by said pump, whereby said clutch is disengaged; and h. temperature control means responsive to said moving of said valve means for withdrawing thermal energy from said liquid in said casing element at a higher rate when said valve means is in said first position than when said valve means is in said second position.
Claim 2
Dependent Claim
214 words
A hydrostatic clutch comprising: a. an input shaft; b. an output shaft; c. a positive displacement pump including a casing element having a cavity, an intake port and a discharge port communicating with said cavity, and a pumping element movable in said cavity, 1. said elements being connected to said shafts respectively for pumping a fluid from said intake port to said discharge port when one of said shafts rotates at a speed different from the speed of rotation of the other shaft; d. conduit means constituting a pumping circuit connecting said ports; e. valve means in said circuit; f. a body of liquid in said circuit and in said casing element; g. actuating means for moving said valve means between a first position in which said valve means blocks said circuit, whereby said clutch is engaged for transmitting torque between said shafts, and a second posiTion in which said liquid is free to be pumped through said circuit by said pump, whereby said clutch is disengaged; and h. temperature control means responsive to said moving of said valve means for withdrawing thermal energy from said liquid in said casing element at a higher rate when said valve means is in said first position than when said valve means is in said second position.
Claim 3
Dependent Claim
80 words
A clutch as set forth in claim 1, wherein said temperature control means include a secondary pump drivingly connected to one of said shafts, a source of cooling fluid, and conduit means constituting a cooling circuit for circulation of said cooling fluid from said source to said secondary pump and back to said source when said secondary pump is driven, the fluid in a portion of said cooling circuit being in heat-transmitting contact with the liquid in said casing element.
Claim 4
Dependent Claim
98 words
said elements being drivingly connected to said shafts respectively for pumping a fluid from said intake port to said discharge port when one of said shafts rotates relative to the other shaft; d. a source of hydraulic fluid; e. a valve interposed between said ports; f. actuating means for opening and closing said valve; g. secondary pump means drivingly connected to one of said shafts and interposed between said source and said intake port for pumping said fluid into said intake port when said connected shaft rotates; and h. a conduit connecting said intake port to said source.
Claim 5
Dependent Claim
98 words
said elements being drivingly connected to said shafts respectively for pumping a fluid from said intake port to said discharge port when one of said shafts rotates relative to the other shaft; d. a source of hydraulic fluid; e. a valve interposed between said ports; f. actuating means for opening and closing said valve; g. secondary pump means drivingly connected to one of said shafts and interposed between said source and said intake port for pumping said fluid into said intake port when said connected shaft rotates; and h. a conduit connecting said intake port to said source.
Claim 6
Dependent Claim
45 words
A clutch as set forth in claim 2, wherein a conduit in said casing is common to said pumping circuit and to said portion of said cooling circuit, said liquid and said fluid are of the same composition and in direct contact in said conduit.
Claim 7
Dependent Claim
31 words
A hydrostatic clutch comprising: a. an input shaft; an output shaft; c. a positive displacement pump including a casing element defining a cavity and a pumping element movable in said cavity,
Claim 8
Dependent Claim
31 words
A hydrostatic clutch comprising: a. an input shaft; an output shaft; c. a positive displacement pump including a casing element defining a cavity and a pumping element movable in said cavity,
Claim 9
Dependent Claim
44 words
A clutch as set forth in claim 4, further comprising a stationary housing, said secondary pump and said valve being mounted on said housing, said shafts being journaled coaxially in said housing, and said elements being fixedly fastened to the respective, drivingly connected shafts.
Claim 10
Dependent Claim
32 words
A clutch as set forth in claim 5, wherein said secondary pump means includes a centrifugal pump having an impeller, said impeller and said casing element being mounted on said input shaft.
Claim 11
Dependent Claim
38 words
A clutch as set forth in claim 5, wherein said secondary pump means includes a positive displacement pump having a movable pump element, the movable pump elements of said positive displacement pumps being mounted on said output shaft.
Claim 12
Dependent Claim
54 words
A clutch as set forth in claim 7, wherein said secondary pump means, said source, and said conduit jointly constitute a cooling circuit, said clutch further comprising secondary valve means in said cooling circuit operatively connected to said actuating means for blocking said cooling circuit when said valve is opened by said actuating means.
Claim 13
Dependent Claim
30 words
A clutch as set forth in claim 5, wherein said pumping element is partly received in said intake port for contact with the fluid pumped by said secondary pump means.
Claim 14
Dependent Claim
22 words
A clutch as set forth in claim 1, wherein said valve means constitutes the only connection of said ports outside said cavity.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |