US3785758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vane pump with ramp on minor diameter
Assignee: Hagglunds Denison Corp
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Filing: 1972-04-24
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Granted: 1974-01-15
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Expires: 1992-04-24
Abstract
Abstract A hydraulic pump of the vane type wherein the cam surface of the stator is formed with a ramp on the minor diameter portion traversed by the vanes as they move from the pressure zone to the suction zone. When vanes of the two lip type are used, an in-ramp is especially desirable for pumps wherein the vane are spring operated, while an out-ramp is especially desirable for pumps wherein the vanes are operated by hydraulic actuators. The provision of such ramps has been found to improve radial balance of the rotor, vane tip sealing, and to reduce pressure ripple, as well as wear.
Inventors
- 👤 J Wilcox
- 👤 C Adams
- 👤 J Swain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:32
CPC Classifications
F; F01; F01C; F01C21/00; F01C21/08; F01C21/0809; F01C21/0818; F01C21/0854; F01C21/0863
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
144 words
In a vane type hydraulic pump having rotor and stator members and vanes mounted in vane slots in one member for engaging a cam surface presented by the other member, a pressure zone and a suction zone in the pumping space between the one member and said cam surface, a transfer zone and a sealing zone in said pumping space alternately between the pressure zone and the suction zone, said vanes being provided with means for biasing them towards the cam surface, the improvement comprising, a ramp on said cam surface extending substantially across said sealing zone, said ramp being an out-ramp and having an angulation of about 1/4 * - 2* and allowing the vanes to move only radially outward relative to the center of rotation of the rotor, as said vanes traverse said sealiNg zone in sealing engagement with said cam surface.
Claim 2
Dependent Claim
144 words
In a vane type hydraulic pump having rotor and stator members and vanes mounted in vane slots in one member for engaging a cam surface presented by the other member, a pressure zone and a suction zone in the pumping space between the one member and said cam surface, a transfer zone and a sealing zone in said pumping space alternately between the pressure zone and the suction zone, said vanes being provided with means for biasing them towards the cam surface, the improvement comprising, a ramp on said cam surface extending substantially across said sealing zone, said ramp being an out-ramp and having an angulation of about 1/4 * - 2* and allowing the vanes to move only radially outward relative to the center of rotation of the rotor, as said vanes traverse said sealiNg zone in sealing engagement with said cam surface.
Claim 3
Dependent Claim
13 words
The improvement of claim 1 wherein said vanes are of the two-lip type.
Claim 4
Dependent Claim
27 words
The improvement of claim 1 wherein said vanes are of the two-lip type and are urged toward the cam surface by hydraulic pressure operated means acting thereon.
Claim 5
Dependent Claim
14 words
The improvement of claim 1 wherein said vanes are of the single lip type.
Claim 6
Dependent Claim
59 words
The improvement of claim 1 wherein the angulation of the ramp is selected to assure a continuous movement of the vanes in one direction relative to the center of rotation of the rotor, thereby avoiding changes of vane-to-rotor slot friction force which changes would affect the magnitude of the bearing force of the vane tip on the cam surface.
Claim 7
Dependent Claim
50 words
The improvement of claim 1 wherein the angulation of the ramp is adequate to provide the said radial vane motion in a pump having a slightly eccentric assembly of its individual components and which pump in operation displays distortion of the cam surface as a result of internal operating pressure.
Claim 8
Dependent Claim
42 words
The improvement of claim 1 wherein the vanes are of the two-lip type and the ramp angulation is substantially the minimum angulation which maintains contact of the cam surface with the same lip of the vane as it traverses said sealing zone.
Claim 9
Dependent Claim
68 words
In a vane pump having vanes of the two-lip type which engage a cam surface, said cam surface including a minor diameter portion, the improvement comprising, a ramp on the said minor diameter portion of the cam surface, said ramp being at substantially the minimum angulation necessary to insure that a selected lip of each vane will continuously contact the cam surface across the said minor diameter portion.
Claim 10
Dependent Claim
68 words
In a vane pump having vanes of the two-lip type which engage a cam surface, said cam surface including a minor diameter portion, the improvement comprising, a ramp on the said minor diameter portion of the cam surface, said ramp being at substantially the minimum angulation necessary to insure that a selected lip of each vane will continuously contact the cam surface across the said minor diameter portion.
Claim 11
Independent Claim
65 words
A method of preventing lip switching as a two-lip vane moves across the minor diameter portion of the cam surface of a vane pump, said method comprising, angulating said minor diameter portion at an angle in the approximate range of 1/4 * - 2* with respect to a circumferential line through the lip of the vane which is in contact with said minor diameter portion.
Claim 12
Independent Claim
65 words
A method of preventing lip switching as a two-lip vane moves across the minor diameter portion of the cam surface of a vane pump, said method comprising, angulating said minor diameter portion at an angle in the approximate range of 1/4 * - 2* with respect to a circumferential line through the lip of the vane which is in contact with said minor diameter portion.
Claim 13
Dependent Claim
41 words
The method of claim 9 wherein said angulation is substantially the minimum angulation necessary for the same lip of each vane to contact the said minor diameter portion regardless of waviness or irregularities in the curvature of said minor diameter portion.
Claim 14
Dependent Claim
125 words
In a vane pump having vanes of the two-lip type and wherein the tops and bottoms of the respective vanes are hydraulically interconnected and the lips of the vanes engage a cam surface having a minor diameter surface portion, the improvement comprising, a ramp on the said minor diameter portion of the cam surface, said ramp being at an angulation and direction such as to maintain a first lip only of each said vane continuously in contact with said minor diameter portion while the respective vane is traversing it, the second lip of the said vane being spaced from the cam surface, the source of pressure exposed to the vane top and vane bottom thereby being unchanging as the vane traverses the minor diameter portion.
Claim 15
Dependent Claim
125 words
In a vane pump having vanes of the two-lip type and wherein the tops and bottoms of the respective vanes are hydraulically interconnected and the lips of the vanes engage a cam surface having a minor diameter surface portion, the improvement comprising, a ramp on the said minor diameter portion of the cam surface, said ramp being at an angulation and direction such as to maintain a first lip only of each said vane continuously in contact with said minor diameter portion while the respective vane is traversing it, the second lip of the said vane being spaced from the cam surface, the source of pressure exposed to the vane top and vane bottom thereby being unchanging as the vane traverses the minor diameter portion.
Claim 16
Dependent Claim
41 words
The improvement of claim 11 wherein the source of pressure to which the said vane top and vane bottom are exposed, is that intervane pocket which is adjacent to and in communication with the said second lip of the said vane.
Claim 17
Dependent Claim
146 words
In a vane type hydraulic pump having rotor and stator members and vanes mounted in vane slots in one member for engaging a cam surface presented by the other member, a pressure zone and a suction zone in the pumping space between the one member and said cam surface, a transfer zone and a sealing zone in said pumping space alternately between the pressure zone and the suction zone, said vanes being provided with means for biasing them towards the cam surface, said vanes being of the two-lip type, the improvement comprising, a ramp on said cam surface extending substantially across said sealing zone, said ramp having an angulation of about - 2* so that as Said vanes traverse said sealing zone in sealing engagement with said cam surface, they move radially in a single direction thereon relative to the center of rotation of the rotor.
Claim 18
Dependent Claim
146 words
In a vane type hydraulic pump having rotor and stator members and vanes mounted in vane slots in one member for engaging a cam surface presented by the other member, a pressure zone and a suction zone in the pumping space between the one member and said cam surface, a transfer zone and a sealing zone in said pumping space alternately between the pressure zone and the suction zone, said vanes being provided with means for biasing them towards the cam surface, said vanes being of the two-lip type, the improvement comprising, a ramp on said cam surface extending substantially across said sealing zone, said ramp having an angulation of about - 2* so that as Said vanes traverse said sealing zone in sealing engagement with said cam surface, they move radially in a single direction thereon relative to the center of rotation of the rotor.
Claim 19
Dependent Claim
19 words
The improvement of claim 13 wherein the vane biasing means are springs, and wherein said ramp is an in-ramp.
Claim 20
Dependent Claim
20 words
The improvement of claim 13 wherein the vane biasing means are hydraulically actuated, and wherein said ramp is an out-ramp.
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) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |