US3775031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary fluid pressure device
Assignee: Danfoss AS
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Filing: 1972-06-14
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Granted: 1973-11-27
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Expires: 1992-06-14
Abstract
Abstract The invention relates to fluid pressure motors and pumps of the type having a gerotor displacement mechanism. The rotary type valving for gerotor mechanisms has first and second sets of alternately arranged ports which have sequential fluid communication with ports of stationary passage which are connected to the displacement chambers. Optimum efficiency normally requires that these ports be formed and positioned with great precision. Auxiliary passages associated with the teeth of the gerotor mechanism itself, and which connect adjacent displacement chambers, effects a precise internal distribution of fluid so that only a gross of coarse fluid distribution is required of the valve ports and the fine or delicate distribution needed for optimum efficiency is performed by the auxiliary passages.
Inventors
- 👤 G Hansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:04
CPC Classifications
F; F04; F04C; F04C2/00; F04C2/08; F04C2/082; F04C2/084; F04C2/10; F04C2/103; F04C2/105
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
247 words
A fluid pressure machine comprising an internally toothed ring gear having an axis, a cooperating externally toothed star gear having fewer teeth than said ring gear disposed eccentrically relative to said ring gear axis, said star gear having rotational movement about its own axis and orbital movement about the axis of said ring gear with the teeth of said gears intermeshing in sealing engagement to form expanding chambers on one side of a line of symmetry and contracting chambers on the other side of said line during relative movement between said gears, and end wall fixedly attached to said ring gear and forming fixed wall means for said chambers, valve means comprising a first valve part fixed relative to said ring gear and a second valve part which rotates in unison with said star gear, a first set of fluid ports in said valve first part having fluid connections with said chambers, said valve second part having a second set of ports cooperable with said first ports of said first valve part to continuously route fluid to said expanding chambers and away from said contracting chambers, articulated auxiliary passage means fixed relative to one of said gears and providing fluid communication between each one of said chambers and adjacent chambers on the opposite side thereof, said fluid communication for each said chambers being substantially blocked by the other of said gears at the instants when one of said chambers is in its maximum or minimum volume condition.
Claim 2
Dependent Claim
247 words
A fluid pressure machine comprising an internally toothed ring gear having an axis, a cooperating externally toothed star gear having fewer teeth than said ring gear disposed eccentrically relative to said ring gear axis, said star gear having rotational movement about its own axis and orbital movement about the axis of said ring gear with the teeth of said gears intermeshing in sealing engagement to form expanding chambers on one side of a line of symmetry and contracting chambers on the other side of said line during relative movement between said gears, and end wall fixedly attached to said ring gear and forming fixed wall means for said chambers, valve means comprising a first valve part fixed relative to said ring gear and a second valve part which rotates in unison with said star gear, a first set of fluid ports in said valve first part having fluid connections with said chambers, said valve second part having a second set of ports cooperable with said first ports of said first valve part to continuously route fluid to said expanding chambers and away from said contracting chambers, articulated auxiliary passage means fixed relative to one of said gears and providing fluid communication between each one of said chambers and adjacent chambers on the opposite side thereof, said fluid communication for each said chambers being substantially blocked by the other of said gears at the instants when one of said chambers is in its maximum or minimum volume condition.
Claim 3
Dependent Claim
28 words
A fluid pressure machine according to claim 1 wherein the spaces between said second ports in the circumferential sense are greater than the spaces between said first ports.
Claim 4
Dependent Claim
25 words
A fluid pressure machine according to claim 2 wherein the circumferential dimensions of all of said ports are less than the maximum possible geometric dimensions.
Claim 5
Dependent Claim
29 words
A fluid pressure machine according to claim 1 wherein said auxiliary passage means are formed in said wall means and are overridden by one face of said star gear.
Claim 6
Dependent Claim
50 words
A fluid pressure machine according to claim 4 wherein said auxiliary passage means comprise tangentially extending grooves between adjacent teeth of said ring gear with each groove extending approximately along a line between the center points of the crests of adjacent teeth and terminating small distances from said center points.
Claim 7
Dependent Claim
26 words
A fluid pressure machine according to claim 5 wherein a radially extending fluid feeding and exhausting groove is connected to each of said tangentially extending grooves.
Claim 8
Dependent Claim
35 words
A fluid pressure machine according to claim 5 wherein one of said grooves is substantially covered by one face of said star gear when the associated one of said chambers has its minimum displacement volume.
Claim 9
Dependent Claim
20 words
A fluid pressure machine according to claim 5 wherein each of said grooves has reduced cross sections at its ends.
Claim 10
Dependent Claim
31 words
A fluid pressure machine according to claim 8 wherein each said groove extends into adjacent chambers on the opposite sides of one of said chambers which has its minimum displacement volume.
Claim 11
Dependent Claim
35 words
A fluid pressure machine according to claim 1 wherein said auxiliary passage means are formed in the teeth of said star gear and cooperate in a valving manner with the teeth of said ring gear.
Claim 12
Dependent Claim
47 words
A fluid pressure machine according to claim 10 wherein said auxiliary passages are grooves to opposite sides of each of said gear teeth with the separating surface area of the crests of the star gear teeth and the troughs therebetween being cooperable with said ring gear teeth.
Claim 13
Dependent Claim
26 words
A fluid pressure machine according to claim 11 wherein said grooves comprise a pair of grooves for the peripheral portion of each said star gear teeth.
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |