US3692432A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-stage positive displacement pump
Assignee: Ford Motor Co
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Filing: 1970-12-22
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Granted: 1972-09-19
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Expires: 1990-12-22
Abstract
Abstract A positive displacement pump comprising a first pumping gear arranged in engagement with second and third pumping gears thereby establishing primary and secondary pump stages; each pump stage being adapted to displace fluid from a low pressure port to a high pressure port, regulator valve means communicating with the high pressure port of each pump for establishing a controlled bypass between said high pressure ports and low pressure fluid supply circuit and a feed-back circuit connecting the inlet side of the secondary pumping stage to the outlet side of said regulator valve means whereby a pressure buildup occurs on said inlet side thereby rendering the secondary pump stage inactive when the driven speed of said pumping gears exceeds a predetermined value, both pumps being active during operation at low speeds and the secondary pump being rendered inactive during operation at high speeds.
Inventors
- 👤 Po-Lung Liang
- 👤 Staley L Pierce Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:16
CPC Classifications
F; F04; F04C; F04C14/00; F04C14/24; F04C14/26; F04C11/00; F04C14/02; F04C2/00; F04C2/08; F04C2/12; F04C2/14; F04C2/18; F16; F16H; F16H61/00; F16H61/0021; F16H61/0025; F04C2270/00; F04C2270/56
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
337 words
A compound pump assembly having a primary stage and a secondary stage, each stage being defined by meshing pumping gear elements, one gear element of each stage being common, a pump body within which said gear elements are rotatably mounted, said pump body defining in part separate high pressure outlet ports and separate low pressure inlet ports for said pumping stages, a high pressure circuit comprising internal passages formed in said pump body communicating with both of the outlet ports, a first fluid supply passage communicating with the inlet side of said primary pump stage, a second fluid supply passage communicating with the low pressure side of said secondary pump stage, a pressure regulating bypass valve means having a valve chamber and a movable valve element situated therein, said valve chamber and said valve element having registering valve lands, said high pressure circuit communicating with said valve chamber, exhaust ports communicating with said valve chamber for receiving fluid bypassed from said high pressure circuit through said valve means, said second supply passage communicating with said valve chamber, unidirectional flow valve means in said second supply passage for preventing flow of fluid from the inlet side of said secondary stage but accommodating transfer of fluid therethrough from said inlet side of said primary stage, means for biasing said valve element in one direction to restrict the degree of communication between said high pressure circuit and said exhaust ports and a pressure area on said valve element in communication with said high pressure circuit for opposing said biasing means whereby said regulator valve means establishes a regulated pressure in said high pressure circuit as the speed of rotation of said gear element changes, the degree of communication between said high pressure circuit and the inlet side of said secondary stage increasing as the degree of bypass flow through said regulator valve means increases, whereby the pressure differential across said secondary stage becomes substantially zero when the fluid supply requirements for said secondary stage are supplied by said secondary stage.
Claim 2
Dependent Claim
337 words
A compound pump assembly having a primary stage and a secondary stage, each stage being defined by meshing pumping gear elements, one gear element of each stage being common, a pump body within which said gear elements are rotatably mounted, said pump body defining in part separate high pressure outlet ports and separate low pressure inlet ports for said pumping stages, a high pressure circuit comprising internal passages formed in said pump body communicating with both of the outlet ports, a first fluid supply passage communicating with the inlet side of said primary pump stage, a second fluid supply passage communicating with the low pressure side of said secondary pump stage, a pressure regulating bypass valve means having a valve chamber and a movable valve element situated therein, said valve chamber and said valve element having registering valve lands, said high pressure circuit communicating with said valve chamber, exhaust ports communicating with said valve chamber for receiving fluid bypassed from said high pressure circuit through said valve means, said second supply passage communicating with said valve chamber, unidirectional flow valve means in said second supply passage for preventing flow of fluid from the inlet side of said secondary stage but accommodating transfer of fluid therethrough from said inlet side of said primary stage, means for biasing said valve element in one direction to restrict the degree of communication between said high pressure circuit and said exhaust ports and a pressure area on said valve element in communication with said high pressure circuit for opposing said biasing means whereby said regulator valve means establishes a regulated pressure in said high pressure circuit as the speed of rotation of said gear element changes, the degree of communication between said high pressure circuit and the inlet side of said secondary stage increasing as the degree of bypass flow through said regulator valve means increases, whereby the pressure differential across said secondary stage becomes substantially zero when the fluid supply requirements for said secondary stage are supplied by said secondary stage.
Claim 3
Dependent Claim
94 words
The combination as set forth in claim 1 wherein said valve element moves in one direction upon an increase in the speed of said gear elements to increase the degree of communication between said high pressure circuit and said exhaust ports and to increase the degree of communication between said high pressure circuit and the inlet side of said secondary pump, and means for supplying a control pressure signal to said valve chamber thereby establishing a force on said valve element that opposes the tendeNcy of said valve element to uncover said exhaust ports.
Claim 4
Dependent Claim
56 words
The combination as set forth in claim 1 wherein said pumping stages comprise a first external gear and second and third external gears meshing with said first external gear, thereby defining two gear meshes, one mesh being associated with each pumping stage, and a common pumping chamber in said pump body for receiving said gear elements.
Claim 5
Dependent Claim
55 words
The combination as set forth in claim 2 wherein said pumping stages comprise a first external gear and second and third external gears meshing with said first external gear, thereby defining two gear meshes, one mesh being associated with each stage, and a common pumping chamber in said pump body for receiving said gear elements.
Claim 6
Dependent Claim
93 words
The combination as set forth in claim 3 wherein said pump body comprises a first body part in which said pumping chamber is formed, a cover plate secured to said first body part and cooperating therewith to define a closed pumping cavity, and a separator plate situated between said cover plate and said first body part, said cover plate being formed with internal passages and said separator plate being formed with a plurality of ports establishing fluid communication between said passages and the low and high pressure sides of each of said stages.
Claim 7
Dependent Claim
93 words
The combination as set forth in claim 4 wherein said pump body comprises a first body part in which said pumping chamber is formed, a cover plate secured to said first body part and cooperating therewith to define a closed pumping cavity, and a separator plate situated between said cover plate and said first body part, said cover plate being formed with internal passages and said separator plate being formed with a plurality of ports establishing fluid communication between said passages and the low and high pressure sides of each of said stages.
Claim 8
Dependent Claim
79 words
The combination as set forth in claim 5 wherein said regulator valve means comprises a valve chamber formed in said body part, and a plurality of valve passages in said first body part communicating with the passages in said cover plate through said separator plate, said first body part also being formed with fluid pressure distributor passages communicating with the high pressure sides and low pressure sides of said stages and communicating with other portions of said valve chamber.
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) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |