US5098351A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Torque distribution control system for a four-wheel drive motor vehicle
Assignee: Subaru Corp
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Filing: 1990-06-21
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Granted: 1992-03-24
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Expires: 2010-06-21
Abstract
Abstract A central differential comprising a planetary gear device is parallel to front axles of a motor vehicle, and coaxially to a transfer shaft of a transfer device. The planetary gear device comprises a first sun gear connected to an output shaft of a transmission, a carrier, first and second planetary pinions integral with each other and rotatably supported on the carrier, and a second sun gear. The first planetary pinion is engaged with the first sun gear, and the second planetary pinion is engaged with the second sun gear. A fluid operated multiple-disk clutch is disposed coaxial to the central differential so as to restrict the differential operation of the planetary gear device.
Inventors
- 👤 Toshio Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:57
CPC Classifications
B; B60; B60K; B60K23/00; B60K23/08; B60K23/0808; B60K17/00; B60K17/34; B60K17/344; B60K17/346; B60K17/3462
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
283 words
A system for controlling torque distribution to front wheels and rear wheels of a motor vehicle having a laterally mounted engine and transmission, and a first differential coaxially mounted on either one set of front or rear wheel axles of the vehicle for differentiating speed between left and right of the wheels of the vehicle on a corresponding set of axles, the system comprising: a transfer device for transmitting torque to the other set of the rear or front wheel axles, said transfer device has a central transfer shaft; a central differential operatively connected between said transmission and said first differential and mounted on said transfer shaft for transmitting respective torque to said first differential and to said transfer shaft; said transfer shaft is spaced from and parallel to said one set of axles; and a final gear meshed with an output gear of the transmission for transmitting power of the engine to said central differential; said central differential comprises a planetary gear device comprising: a first sun gear coaxially and relatively rotatably mounted with respect to said transfer shaft and driven by said final gear; a second sun gear jointly rotatably connected with said transfer shaft; and a planetary gearing supported in a carrier and meshed with said first and second sun gears for differentiating speed between said front and rear wheels; a fluid-operated multiple-disk clutch connected to said carrier and mounted compactly and coaxially with respect to said transfer shaft for restricting differential operation of said planetary gear device; and control means for controlling said clutch for accurately distributing torque to each front and rear wheels of the vehicle at an optimum ratio in accordance with driving conditions of said vehicle.
Claim 2
Independent Claim
283 words
A system for controlling torque distribution to front wheels and rear wheels of a motor vehicle having a laterally mounted engine and transmission, and a first differential coaxially mounted on either one set of front or rear wheel axles of the vehicle for differentiating speed between left and right of the wheels of the vehicle on a corresponding set of axles, the system comprising: a transfer device for transmitting torque to the other set of the rear or front wheel axles, said transfer device has a central transfer shaft; a central differential operatively connected between said transmission and said first differential and mounted on said transfer shaft for transmitting respective torque to said first differential and to said transfer shaft; said transfer shaft is spaced from and parallel to said one set of axles; and a final gear meshed with an output gear of the transmission for transmitting power of the engine to said central differential; said central differential comprises a planetary gear device comprising: a first sun gear coaxially and relatively rotatably mounted with respect to said transfer shaft and driven by said final gear; a second sun gear jointly rotatably connected with said transfer shaft; and a planetary gearing supported in a carrier and meshed with said first and second sun gears for differentiating speed between said front and rear wheels; a fluid-operated multiple-disk clutch connected to said carrier and mounted compactly and coaxially with respect to said transfer shaft for restricting differential operation of said planetary gear device; and control means for controlling said clutch for accurately distributing torque to each front and rear wheels of the vehicle at an optimum ratio in accordance with driving conditions of said vehicle.
Claim 3
Dependent Claim
29 words
The system according to claim 1, wherein said first sun gear is formed on an input shaft of said central differential, said input shaft meshes with said final gear.
Claim 4
Dependent Claim
21 words
The system according to claim 1, wherein said fluid-operated multiple-disk clutch is connected between said carrier and said first sun gear.
Claim 5
Dependent Claim
21 words
The system according to claim 1, wherein said fluid-operated multiple-disk clutch is connected between said carrier and said second sun gear.
Claim 6
Dependent Claim
28 words
The system according to claim 1, wherein said output gear is connected to a hub member of said first differential, said hub member has said final gear thereon.
Claim 7
Dependent Claim
50 words
The system according to claim 1, wherein said central differential has a first output shaft coaxially and jointly rotatably connected to said transfer shaft, and said first sun gear is relatively rotatably mounted on said first output shaft and said second sun gear is formed on said first output shaft.
Claim 8
Dependent Claim
39 words
The system according to claim 1, wherein said central differential has a first output shaft coaxially and jointly rotatably connected to said transfer shaft, and said clutch is mounted concentrically around and relatively rotatably to said first output shaft.
Claim 9
Dependent Claim
65 words
The system according to claim 1, wherein the planetary gear device is arranged with such a rear-deviated distribution that a larger torque than the torque to the front wheels is transmitted to the rear wheels, and clutch torque is controlled such that the torque distribution is changed between the rear-deviated distribution and the distribution corresponding to the axle loads of the front and rear wheels.
Claim 10
Dependent Claim
37 words
The system according to claim 8, wherein the control means comprises a hydraulic circuit for supplying pressurized oil to the fluid-operated multiple-disk clutch, and a control unit for controlling the pressure of oil supplied to the clutch.
Claim 11
Dependent Claim
145 words
The system according to claim 9, wherein the hydraulic circuit comprises an oil pump, a pressure regulator valve for regulating the pressure of the oil supplied from the oil pump to produce a line pressure, a clutch control valve for controlling the oil supplied to the clutch, a solenoid-operated duty control valve for controlling the pressure of the oil supplied to the clutch control valve, the control unit comprises a slip ratio calculator for calculating slip ratio between the rear wheels and the front wheels in accordance with the ratio between the front-wheel speed and the rear-wheel speed, clutch pressure setting means responsive to the slip ratio for providing a clutch pressure, and duty ratio providing means responsive to the clutch pressure for producing pulses having a duty ratio corresponding to the clutch pressure to the duty control valve for controlling the pressure of oil.
Claim 12
Independent Claim
278 words
A system for controlling torque distribution to front wheels and rear wheels of a motor vehicle having a laterally mounted engine and transmission, and a first differential coaxially mounted on either one set of front or rear wheel axles of the vehicle for differentiating speed between left and right of the wheels of the vehicle on a corresponding set of ales, the system comprising: a transfer device for transmitting torque to the other set of the rear or front wheel axles, said transfer device has a central transfer shaft; a central differential operatively connected between said transmission and said first differential and mounted on said transfer shaft for transmitting respective torques to said first differential and to said transfer shaft; said transfer shaft is spaced from and parallel to said one set of axles; and a final gear meshed with an output gear of the transmission for transmitting power of the engine to said central differential; said central differential comprises a planetary gear device comprising: a first sun gear coaxially and relatively rotatably mounted with respect to said transfer shaft and driven by said final gear; a second sun gear jointly rotatably connected with said transfer shaft; and a planetary gearing supported in a carrier and meshed with said first and second sun gears for differentiating speed between said front and rear wheels; a fluid-operated multiple-disk clutch mounted compactly and coaxially with respect to said transfer shaft for restricting differential operation of said planetary gear device; and control means for controlling said clutch for accurately distributing torque to each front and rear wheels of the vehicle at an optimum ratio in accordance with driving conditions of said vehicle.
Claim 13
Independent Claim
278 words
A system for controlling torque distribution to front wheels and rear wheels of a motor vehicle having a laterally mounted engine and transmission, and a first differential coaxially mounted on either one set of front or rear wheel axles of the vehicle for differentiating speed between left and right of the wheels of the vehicle on a corresponding set of ales, the system comprising: a transfer device for transmitting torque to the other set of the rear or front wheel axles, said transfer device has a central transfer shaft; a central differential operatively connected between said transmission and said first differential and mounted on said transfer shaft for transmitting respective torques to said first differential and to said transfer shaft; said transfer shaft is spaced from and parallel to said one set of axles; and a final gear meshed with an output gear of the transmission for transmitting power of the engine to said central differential; said central differential comprises a planetary gear device comprising: a first sun gear coaxially and relatively rotatably mounted with respect to said transfer shaft and driven by said final gear; a second sun gear jointly rotatably connected with said transfer shaft; and a planetary gearing supported in a carrier and meshed with said first and second sun gears for differentiating speed between said front and rear wheels; a fluid-operated multiple-disk clutch mounted compactly and coaxially with respect to said transfer shaft for restricting differential operation of said planetary gear device; and control means for controlling said clutch for accurately distributing torque to each front and rear wheels of the vehicle at an optimum ratio in accordance with driving conditions of said vehicle.
Claim 14
Dependent Claim
21 words
The system according to claim 11, wherein said fluid-operated multiple-disk clutch is connected between said first and said second sun gears.
Claim 15
Dependent Claim
36 words
The system according to claim 11, wherein said central differential has a first output shaft coaxially and jointly rotatably connected to said transfer shaft, and said clutch is mounted concentrically joined on said first output shaft.
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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) | 1995-03-24 | 1995-09-23 | 1996-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-24 | 1999-09-23 | 2000-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-24 | 2003-09-23 | 2004-03-24 | $7700.00 | Window Closed / Lapsed |