Patent US4729262A successfully refreshed from Google Patents.
US4729262A
Expired / Lapsed
US
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Transmission unit
Assignee: Steyr Daimler Puch AG
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Filing: 1986-09-10
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Granted: 1988-03-08
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Expires: 2006-09-10
Abstract
Abstract A transmission unit particularly intended for use as a differential between driven axles of a vehicle comprises an epicyclic gear train having three rotatable members, specifically, an input member connected to an input shaft, a second member connected to one section of a liquid friction coupling, and an output member connected to an output shaft. To avoid an occurrence of constraining torques as the vehicle is steered and to permit a modulation within a wide range of the relationship between the speed difference between the sections of the coupling and the torque limit of the transmission unit, the second section of the liquid friction coupling is non-rotatably connected to a stationary structure of the transmission unit, specifically to a housing of the epicyclic gear train. Alternatively, said second section of the coupling may be adapted to be held against rotation by a brake, so that the axles of the vehicles can easily be uncoupled from each other. Output torque is delivered from the transmission unit only by the output member of the epicyclic gear train.
Inventors
- 👤 Heribert Lanzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:16
CPC Classifications
F; F16; F16D; F16D35/00; F16D35/005; B; B60; B60K; B60K17/00; B60K17/34; B60K17/348; B60K17/35; B60K17/3505; B60K17/351; F16H; F16H48/00; F16H48/06; F16H48/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
168 words
A transmission unit for a motor vehicle, comprising a drive shaft having two ends, first and second driven axles, a gear unit installed between said first and second driven axles, said gear unit driving said first driven axle and controlling the relative rotational speeds of said first and second driven axles, said gear unit comprising an epicyclic gear train having a first rotatable input member connected to and being driven by one end of said drive shaft, a second rotatable member, and a third rotatable output member connected to and driving said first driven axle, a liquid friction clutch unit having first and second sections coupled to each other by viscous shear forces, said second rotatable member of said gear train connected to said first coupling section, and restraining means connected to said second coupling section for holding said second coupling section and thereby said second rotatable member against rotation, said second driven axle being connected to and being driven by said other end of said drive shaft.
Claim 2
Dependent Claim
168 words
A transmission unit for a motor vehicle, comprising a drive shaft having two ends, first and second driven axles, a gear unit installed between said first and second driven axles, said gear unit driving said first driven axle and controlling the relative rotational speeds of said first and second driven axles, said gear unit comprising an epicyclic gear train having a first rotatable input member connected to and being driven by one end of said drive shaft, a second rotatable member, and a third rotatable output member connected to and driving said first driven axle, a liquid friction clutch unit having first and second sections coupled to each other by viscous shear forces, said second rotatable member of said gear train connected to said first coupling section, and restraining means connected to said second coupling section for holding said second coupling section and thereby said second rotatable member against rotation, said second driven axle being connected to and being driven by said other end of said drive shaft.
Claim 3
Dependent Claim
29 words
The transmission unit set forth in claim 1 wherein said liquid friction clutch unit is actuable to control the relative rotational speeds of said first and second driven axles.
Claim 4
Dependent Claim
25 words
The transmission unit set forth in claim 1, wherein said restraining means comprise a stationary structure which is non-rotatably connected to said second coupling section.
Claim 5
Dependent Claim
30 words
The transmission unit set forth in claim 3, wherein said stationary structure comprises a housing, which accommodates said epicyclic gear train and is non-rotatably connected to said second coupling section.
Claim 6
Dependent Claim
23 words
The transmission unit set forth in claim 1, wherein said restraining means comprise a brake for holding said second coupling section against rotation.
Claim 7
Dependent Claim
68 words
A transmission unit as set forth in claim 5 wherein a second liquid friction clutch unit is provided, which has a first coupling section, which is connected to said second part of said epicyclic gear train, and a second coupling section, and first and second brakes are provided, which are mutually independently operable to hold said second coupling sections of both said liquid friction clutch units against rotation.
Claim 8
Dependent Claim
19 words
The transmission unit set forth in claim 6, wherein said liquid friction clutch units differ in their inherent characteristics.
Claim 9
Dependent Claim
67 words
The transmission unit set forth in claim 6, wherein said liquid friction clutch units define for said transmission unit a torque limit depending on the speed difference between the first and second coupling sections of each of said liquid friction clutch units and control means are provided for controlling said liquid friction couplings so as to modulate the relationship between said speed differences and said torque limit.
Claim 10
Dependent Claim
15 words
The transmission unit set forth in claim 8, wherein said control means are arbitrarily operable.
Claim 11
Dependent Claim
15 words
The transmission unit set forth in claim 8, wherein said control means are automatically operable.
Claim 12
Dependent Claim
60 words
The transmission unit set forth in claim 1, wherein said liquid friction clutch unit determines for said transmission unit a torque limit depending on the speed difference between said first and second coupling sections and control means are provided for controlling said liquid friction clutch unit so as to modulate the relationship between said speed difference and said torque limit.
Claim 13
Dependent Claim
26 words
The transmission unit set forth in claim 11, wherein control means are provided for changing the quantity of liquid contained in said liquid friction clutch unit.
Claim 14
Dependent Claim
36 words
The transmission unit set forth in claim 11, wherein said first and second coupling sections have interdigitating elements, which define clearances between them, and control means are provided for changing the clearances between said interdigitating elements.
Claim 15
Dependent Claim
23 words
The transmission unit set forth in claim 11, wherein control means are provided for changing the pressure in said liquid friction clutch unit.
Claim 16
Dependent Claim
15 words
The transmission unit set forth in claim 11, wherein said control means are arbitrarily operable.
Claim 17
Dependent Claim
15 words
The transmission unit set forth in claim 11, wherein said control means are automatically operable.
Claim 18
Dependent Claim
43 words
The transmission set forth in claim 1, wherein said epicyclic gear train comprising a planetary gear train having a rotatable input member comprising a planet carrier, a rotatable second member comprising a sun gear, and a rotatable output member comprising an internal gear.
Claim 19
Dependent Claim
19 words
The transmission unit of claim 6 wherein said first and second liquid friction clutch units are connected in parallel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-08 | 1991-09-07 | 1992-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-08 | 1995-09-07 | 1996-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-08 | 1999-09-07 | 2000-03-08 | $7700.00 | Window Closed / Lapsed |