US3881849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gear pumps
Assignee: Rhone Poulenc SA
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Filing: 1972-12-07
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Granted: 1975-05-06
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Expires: 1992-12-07
Abstract
Abstract A gear pump is constructed entirely of ceramic material, and includes a body having two side plates and an intermediate member, the latter being formed with two communicating part cylindrical seats in which meshing gear wheels can rotate without bearings. A drive shaft engages in a recess in one of the gear wheels, the recess being of a non-circular cross-section and the shaft engaging therein with a clearance.
Inventors
- 👤 Roger Commarmot
- 👤 Michel Pequignot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:56
CPC Classifications
F; F04; F04C; F04C13/00; F04C13/001; F04C15/00; F04C15/0057; F04C15/0061; F04C15/0073; F04C2/00; F04C2/08; F04C2/082; F04C2/084; F04C2/086; F05; F05C; F05C2203/00; F05C2203/08
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
211 words
In a gear pump comprising two intermeshing cylindrical gear wheels located in two part cylindrical communicating seats of the body of the pump provided with inlet and outlet orifices for the fluid, and with an orifice for the passage of the drive shaft for driving the driven gear wheel, each of said orifices being located in an end wall of the body of the pump, the improvement which consists in that: a. the said body of the pump, the drive shaft, and the gear wheels are formed entirely of a ceramic material; b. the axial clearance between each gear wheel and its seat is less than 20 microns and the diametral clearance between each gear wheel and its seat is less than 50 microns; c. each gear wheel is mounted effective to be guided solely by the walls of its seating, which directly enclose at least 80 percent of the total number of gear teeth of the respective gear wheel; and d. the drive shaft engages freely and with play in a noncircular cross-section recess in an end face of the driven gear wheel and passes through the body of the pump through an orifice, the diametral clearaNce between the drive shaft, and the orifice being between 2 and 10 microns.
Claim 2
Dependent Claim
211 words
In a gear pump comprising two intermeshing cylindrical gear wheels located in two part cylindrical communicating seats of the body of the pump provided with inlet and outlet orifices for the fluid, and with an orifice for the passage of the drive shaft for driving the driven gear wheel, each of said orifices being located in an end wall of the body of the pump, the improvement which consists in that: a. the said body of the pump, the drive shaft, and the gear wheels are formed entirely of a ceramic material; b. the axial clearance between each gear wheel and its seat is less than 20 microns and the diametral clearance between each gear wheel and its seat is less than 50 microns; c. each gear wheel is mounted effective to be guided solely by the walls of its seating, which directly enclose at least 80 percent of the total number of gear teeth of the respective gear wheel; and d. the drive shaft engages freely and with play in a noncircular cross-section recess in an end face of the driven gear wheel and passes through the body of the pump through an orifice, the diametral clearaNce between the drive shaft, and the orifice being between 2 and 10 microns.
Claim 3
Dependent Claim
66 words
In a pump according to claim 1, the improvements which consist in that the pump body comprises two side plates and an intermediate gear pump member in direct contact with said side plates, the intermediate member having said part cylindrical surfaces extending through the entire thickness thereof, said two plates and intermediate member being assembled in fluid tight manner with the aid of mechanical clamping means.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |