Patent US3774735A successfully refreshed from Google Patents.
US3774735A
Expired / Lapsed
US
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Hydrodynamic retarder for vehicles
Assignee: Daimler Benz AG
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Filing: 1972-01-17
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Granted: 1973-11-27
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Expires: 1992-01-17
Abstract
Abstract A hydrodynamic retarder for vehicles, especially motor vehicles which includes an internal working circulation between a rotating and a stationary bladed wheel within a working space and an external cooling circulation with a by-pass valve; the filling of the working circulation takes place from a filling cylinder actuated by pressure medium and controlled by a control valve, for example by the brake pedal; the sealed space located directly in front of the shaft seal within the retarder housing is relieved toward a place of the working circulation that is pressureless during operation while a supply tank for working liquid is provided which is connected with the cooling circulation by way of a first check valve that opens in the direction toward the cooling circulation and with the relief line, connecting the space in front of the shaft seal with the working space, by way of a second check valve which closes in the direction toward the relief line.
Inventors
- 👤 H Hanke
- 👤 W Peter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:18
CPC Classifications
F; F16; F16D; F16D57/00; F16D57/04; B; B60; B60T; B60T1/00; B60T1/02; B60T1/08; B60T1/087
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
356 words
A hydrodynamic retarder installation comprising: a brake housing; at least one fixed blade wheel and one rotatable blade wheel arranged in spaced facing relationship to one another in said housing; a working fluid circulatory system for supplying working fluid to a working chamber formed between said fixed and rotatable blade wheels to effect braking of a shaft connected to said rotatable blade wheel; brake actuating means for controlling said supply of working fluid to said working chamber; a shaft seal interposed between said housing and said shaft to limit escape of working fluid from said housing along said shaft; first conduit means for directly communicating the core of said working chamber with a seal space between said housing and said shaft which is sealed off by the shaft seal such that the low pressure experienced at said core during supply of working fluid with a rapidly rotating shaft relieves said shaft seal; supply tank means containing a supply of working fluid; second conduit means for communicating said supply tank means with said working fluid circulatory system by way of a first check valve means which permits flow through said second conduit means from said supply tank means to said working fluid circulatory system and which prevents flow through said second conduit means from said working fluid circulatory system to said supply tank means, whereby working fluid can be supplied to said working fluid circulatory system by way of said first check valve means without backflow from said working fluid circulatory system to said supply tank means through said second conduit means; and third conduit means for communicating said supply tank means with said first conduit meAns by way of a second check valve means which prevents flow through said third conduit means from said supply tank means in a direction toward said core and seal space and which permits flow through said third conduit means from said core and seal space to said supply tank means, whereby an excessive pressure build-up in said seal space is automatically limited by said second check valve means permitting fluid flow from said seal space to said supply tank means.
Claim 2
Dependent Claim
356 words
A hydrodynamic retarder installation comprising: a brake housing; at least one fixed blade wheel and one rotatable blade wheel arranged in spaced facing relationship to one another in said housing; a working fluid circulatory system for supplying working fluid to a working chamber formed between said fixed and rotatable blade wheels to effect braking of a shaft connected to said rotatable blade wheel; brake actuating means for controlling said supply of working fluid to said working chamber; a shaft seal interposed between said housing and said shaft to limit escape of working fluid from said housing along said shaft; first conduit means for directly communicating the core of said working chamber with a seal space between said housing and said shaft which is sealed off by the shaft seal such that the low pressure experienced at said core during supply of working fluid with a rapidly rotating shaft relieves said shaft seal; supply tank means containing a supply of working fluid; second conduit means for communicating said supply tank means with said working fluid circulatory system by way of a first check valve means which permits flow through said second conduit means from said supply tank means to said working fluid circulatory system and which prevents flow through said second conduit means from said working fluid circulatory system to said supply tank means, whereby working fluid can be supplied to said working fluid circulatory system by way of said first check valve means without backflow from said working fluid circulatory system to said supply tank means through said second conduit means; and third conduit means for communicating said supply tank means with said first conduit meAns by way of a second check valve means which prevents flow through said third conduit means from said supply tank means in a direction toward said core and seal space and which permits flow through said third conduit means from said core and seal space to said supply tank means, whereby an excessive pressure build-up in said seal space is automatically limited by said second check valve means permitting fluid flow from said seal space to said supply tank means.
Claim 3
Dependent Claim
39 words
A retarder installation according to claim 1, further comprising an external cooling circulatory means having a cooler and a by-pass valve means, said cooling circulatory means being connected to said working fluid circulatory system for cooling the working fluid.
Claim 4
Dependent Claim
32 words
A retarder installation according to claim 1, characterized in that the second check valve means includes a spring which is adjusted at most to the maximum permissive pressure of the seal means.
Claim 5
Dependent Claim
56 words
A retarder installation according to claim 1, characterized in that a float means is arranged in the supply tank means which is so connected with a switch means that a warning signal appears in the field of vision of the driver when the liquid level in the supply tank means drops below a predetermined minimum level.
Claim 6
Dependent Claim
39 words
A retarder installation according to claim 6, further comprising an external cooling circulatory means having a cooler and a by-pass valve means, said cooling circulatory means being connected to said working fluid circulatory system for cooling the working fluid.
Claim 7
Dependent Claim
39 words
A retarder installation according to claim 1, wherein the brake actuating means includes a filling cylinder means actuable in response to a pressure medium and control valve means for controlling the pressure medium for actuating said filling cylinder means.
Claim 8
Dependent Claim
32 words
A retarder installation according to claim 6, wherein the supply tank means is positioned with the level of working fluid therein normally above both the working chamber and the filling cylinder means.
Claim 9
Dependent Claim
72 words
A retarder installation according to claim 7, characterized in that a two-way valve means is arranged between the supply tank means and the cooling circulatory means in parallel to the first check valve means, said two-way valve means being open in the idling non-braking position of the retarder installation and being operable to be closed as a function of the braking operation at the latest upon response of the filling cylinder means.
Claim 10
Dependent Claim
31 words
A retarder installation according to claim 8, characterized in that the two-way valve means is closed in dependence of the braking operation shortly before the response of the filling cylinder means.
Claim 11
Dependent Claim
20 words
A retarder installation according to claim 8, characterized in that the first check valve means is constructed as relief valve.
Claim 12
Dependent Claim
48 words
A retarder installation according to claim 8, characterized in that a solenoid valve is provided as the two-way valve means which closes upon energization thereof and which includes an energizing circuit provided with a switch closing upon actuation of the control valve means for the filling cylinder means.
Claim 13
Dependent Claim
44 words
A retarder installation according to claim 8, characterized in that the two-way valve means includes a control member and in that a side of the filling cylinder means actuated by the pressure medium is connected with the control member of the two-way valve means.
Claim 14
Dependent Claim
49 words
A retarder installation according to claim 8, characterized in that the first check valve means includes a spring which is so adjusted that a flow and refilling of working liquid from the supply tank means into the filling cylinder means is posible also with a closed two-way valve means.
Claim 15
Dependent Claim
32 words
A retarder installation according to claim 13, characterized in that the second check valve means includes a spring which is adjusted at most to the maximum permissive pressure of the shaft seal.
Claim 16
Dependent Claim
30 words
A retarder installation according to claim 14, characterized in that the spring of the second check valve means is adjusted slightly below the maximum permissive pressure of the shaft seal.
Claim 17
Dependent Claim
34 words
A retarder installation according to claim 14, characterized in that the spring side of the by-pass valve means is connected with a line between the second check valve means and the supply tank means.
Claim 18
Dependent Claim
34 words
A retarder installation according to claim 14, characterized in that a spring side of the by-pass valve means is connected with a line between the second check valve means and the supply tank means.
Claim 19
Dependent Claim
33 words
A retarder installation according to claim 17, characterized in that the supply tank means as well as the two check valve means and the two-way valve means are combined into a structural unit.
Claim 20
Dependent Claim
24 words
A retarder installation according to claim 18, characterized in that the filling cylinder means is constructed as a piston accumulator actuated by compressed air.
Claim 21
Dependent Claim
24 words
A retarder installation according to claim 18, characterized in that the filling cylinder means is constructed as a diaphragm accumulator actuated by compressed air.
Claim 22
Dependent Claim
56 words
A retarder installation according to claim 18, characterized in that a float means is arranged in the supply tank means which is so connected with a switch means that a warning signal appears in the field of vision of the driver when the liquid level in the supply tank means drops below a predetermined minimum level.
Claim 23
Dependent Claim
48 words
A retarder installation according to claim 21, characterized in that a solenoid valve is provided as the two-way valve means which closes upon energization thereof and which includes an energizing circuit provided with a switch closing upon actuation of the control valve means for the filling cylinder means.
Claim 24
Dependent Claim
44 words
A retarder installation according to claim 21, characterized in that the two way-valve means includes a control member and in that a side of the filling cylinder means actuated by the pressure medium is connected with the control member of the two-way valve means.
Claim 25
Dependent Claim
18 words
A retarder installation according to claim 6, wherein said control valve means is controlled by brake pedal means.
Claim 26
Dependent Claim
39 words
A retarder installation according to claim 24, further comprising an external cooling circulatory means having a cooler and a by-pass valve means, said cooling circulatory means being connected to said working fluid circulatory system for cooling the working fluid.
Claim 27
Dependent Claim
72 words
A retarder installation according to claim 25, characterized in that a two-way valve means is arranged between the supply tank means and the cooling circulatory means in parallel to the first check valve means, said two-way valve means being open in the idling non-braking position of the retarder installation and being operable to be closed as a function of the braking operation at the latest upon response of the filling cylinder means.
Claim 28
Dependent Claim
31 words
A retarder installation according to claim 26, characterized in that the two-way valve means is closed in dependence of the braking operation shortly before the response of the filling cylinder means.
Claim 29
Dependent Claim
48 words
A retarder installation according to claim 26, characterized in that a solenoid valve is provided as the two-way valve means which closes upon energization thereof and which includes an energizing circuit provided with a switch closing upon actuation of the control valve means for the filling cylinder means.
Claim 30
Dependent Claim
44 words
A retarder installation according to claim 26, characterized in that the two-way valve means includes a control member and in that the side of the filling cylinder means actuated by the pressure medium is connected with the control member of the two-way valve means.
Claim 31
Dependent Claim
49 words
A retarder installation according to claim 26, characerized in that the first check valve means includes a spring which is so adjusted that a flow and refilling of working liquid from the supply tank means into the filling cylinder means is possible also with a closed two-way valve means.
Claim 32
Dependent Claim
33 words
A retarder installation according to claim 26, characterized in that the supply tank means as well as the two check valve means and the two-way valve means are combined into a structural unit.
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 |