US 6,474,433 B1Granted

Speed sensitive on-demand torque coupling differential

AssigneeSpicer Technology, Inc.

InventorJun Yoshioka

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Abstract

An axle case assembly is provided with a speed sensitive torque coupling mechanism used to transmit torque from the ring gear to a planetary differential assembly. The differential assembly provides torque transfer proportional to the speed difference between the ring gear sub-assembly and a planetary gear set sub-assembly, wherein the invention splits a differential case assembly into two primary pieces and a speed sensitive mechanism is installed between each piece. The mechanism is entirely contained inside an axle differential case assembly. An optional limited slip device may be provided for the differential gears. The torque transmission coupling assembly eliminates the need for a center differential in the transfer case, i.e. an interaxle differential, thereby reducing the driveline complexity and cost without requiring a separate torque coupling in the transfer case or in-line with the driveline.

Claims12

Dependent claims

A four-wheel-drive vehicle comprising:

(a) an engine;
(b) a first differential which is driven by said engine to drive one of a front wheel drive system and a rear wheel drive system;
(c) a second differential which is drivingly connected to the other one of said front and rear wheel drive systems;
and
(d) a torque transmission coupling which is provided between said first and second differentials, said torque transmission coupling comprising:
(i) an input member driven by said transmission;
(ii) an output member drivingly connected to said second differential;
(iii) an oil pump drivingly connected to said input member and said output member to generate oil pressure in response to a speed of a relative rotation due to oil pressure supplied to said oil pump corresponding to revolution of said engine;
and
(iv) a friction clutch mechanism which engages said input shaft and said output shaft with each other by said oil pressure generated by said oil pump,
wherein said friction clutch mechanism transmits torque from a ring gear to a differential case of said second differential, and
wherein said pump, said friction clutch mechanism and said differential case of said second differential are contained within a first outer housing driven by said ring gear.

9 more elements

A four-wheel-drive vehicle comprising:

(a) an engine;
(b) a first differential which is driven by said engine to drive one of a front wheel drive system and a rear wheel drive system;
(c) a second differential which is drivingly connected to the other one of said front and rear wheel drive systems;
and
(d) a torque transmission coupling which is provided between said first and second differentials, said torque transmission coupling comprising:
(i) an input member driven by said transmission;
(ii) an output member drivingly connected to said second differential;
(iii) an oil pump drivingly connected to said input member and said output member to generate oil pressure in response to a speed of a relative rotation due to oil pressure supplied to said oil pump corresponding to revolution of said engine;
and
(iv) a friction clutch mechanism which engages said input shaft and said output shaft with each other by said oil pressure generated by said oil pump,
wherein said friction clutch mechanism transmits torque from a ring gear to a differential case of said second differential, and
wherein said pump, said friction clutch mechanism and said differential case of said second differential are aligned along a single axis of rotation defined by output shafts of said second differential.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/458,940Filed 10 Dec 1999
Granted: 5 Nov 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

F16H 48/22
Arrangements for suppressing or influencing the differential action, e.g. locking devices: using friction clutches or brakes
B60K 17/3505
Including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches: with self-actuated means, e.g. by difference of speed
F16D 25/0638
With flat friction surfaces, e.g. discs: with more than two discs, e.g. multiple lamellae
F16D 43/284
Actuated by fluid pressure: controlled by angular speed