US3901628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic pump with air vent valve
Assignee: Bosch Rexroth AG
•
Filing: 1974-04-24
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Granted: 1975-08-26
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Expires: 1994-04-24
Abstract
Abstract A hydraulic vane pump wherein the intake opening of an air vent valve communicates with the chambers which sweep past the pump outlet and the discharge opening of the valve communicates with a channel which is provided in the pump housing for leak fluid. The valve member of the valve is held in open position by a weak spring during priming of the pump but yields and enables the valve member to seal the intake opening from the discharge opening in response to increasing fluid pressure at the outlet when the priming is completed. The body of the valve is insertable into a compartment of the housing at that axial end of the rotor which is remote from the outlet.
Inventors
- 👤 Siegfried Bornholt
- 👤 Georg Schmitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:25
CPC Classifications
F; F04; F04C; F04C14/00; F04C14/18; F04C14/22; F04C15/00; F04C15/0053
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
197 words
In a hydraulic pump, particularly a vane pump, a combination comprising a stator including housing means formed with an axial bore having a closed end and an open end, said stator having inlet means for admission of hydraulic fluid, and outlet means for pressurized fluid; a rotor in said stator; shaft means coaxial with and fixed to said rotor, said shaft means having a pair of coaxial portions respectively projecting to opposite sides of said rotor and being rotatably mounted in said axial bore, one of said portions projecting beyond the open end of said bore and the other of said portions ends short of said closed end of said bore so as to define with said closed end a pocket for fluid leaking along said shaft means; channel means for evacuation of leak fluid from said pocket; and an air vent valve installed in said stator, said valve having an intake opening cummunicating with said outlet means, a discharge opening communicating with said pocket, and a valve member arranged to seal said openings from each other in response to increasing fluid pressure at said inlet opening such as develops on completion of priming of the pump.
Claim 2
Dependent Claim
197 words
In a hydraulic pump, particularly a vane pump, a combination comprising a stator including housing means formed with an axial bore having a closed end and an open end, said stator having inlet means for admission of hydraulic fluid, and outlet means for pressurized fluid; a rotor in said stator; shaft means coaxial with and fixed to said rotor, said shaft means having a pair of coaxial portions respectively projecting to opposite sides of said rotor and being rotatably mounted in said axial bore, one of said portions projecting beyond the open end of said bore and the other of said portions ends short of said closed end of said bore so as to define with said closed end a pocket for fluid leaking along said shaft means; channel means for evacuation of leak fluid from said pocket; and an air vent valve installed in said stator, said valve having an intake opening cummunicating with said outlet means, a discharge opening communicating with said pocket, and a valve member arranged to seal said openings from each other in response to increasing fluid pressure at said inlet opening such as develops on completion of priming of the pump.
Claim 3
Dependent Claim
54 words
The combination of claim 1, wherein said valve includes a body which is provided with said openings and contains said valve member, said stator having a compartment for said body and being providEd with first and second passages respectively connecting said intake opening with said outlet means and said discharge opening with said pocket.
Claim 4
Dependent Claim
31 words
The combination of claim 1, wherein said channel means extends substantially radially of said rotor and is located substantially diametrically opposite said valve with respect to the axis of said rotor.
Claim 5
Dependent Claim
47 words
The combination as defined in claim 1, wherein said housing means comprises a main body in which said rotor is located and a cover, said inlet means and said outlet means being provided in said main body and said air vent valve being mounted in said cover.
Claim 6
Dependent Claim
49 words
The combination of claim 1, wherein said valve further comprises a seat between said openings and means for biasing said valve member away from said seat with a force which is overcome by said valve member in response to a predetermined rise of fluid pressure at said intake opening.
Claim 7
Dependent Claim
12 words
The combination of claim 5, wherein said valve member is a sphere.
Claim 8
Dependent Claim
37 words
The combination as defined in claim 1, wherein said outlet means is adjacent said one portion of said shaft means and said valve is installed in said stator adjacent to the other portion of said shaft means.
Claim 9
Dependent Claim
46 words
The combination of claim 7, wherein said stator and said rotor define a plurality of variable-volume chambers which sweep past said inlet and outlet means in response to rotation of said rotor and said intake opening communicates with successive chambers which sweep past said outlet means.
Claim 10
Dependent Claim
24 words
The combination of claim 8, wherein said stator has a passage which connects said intake opening with successive chambers sweeping past said outlet means.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |