Active bi-directional overrunning clutch indexing

#1. Field of the Invention

#The present invention relates to clutches, and more particularly, relates to an active indexing bi-directional overrunning clutch.

#2. Description of Related Art

#FIG. 1 shows a plan view of a vehicle drive line.

#FIG. 2 shows a cross section of the present invention.

#FIG. 3 shows a partial cross section taken from the front of the present invention.

#Referring to the drawings, an active bi-directional overrunning clutch 10 according to the present invention is shown. FIG. 1 schematically illustrates an all wheel drive or four wheel drive motor vehicle that is primarily a front wheel driven vehicle, however, the present invention can be used on a primary rear wheel driven vehicle as well.

#The motor vehicle 12 as shown in FIG. 1 is primarily driven by a front axle 14. The motor vehicle 12 is an all wheel drive or a four wheel drive vehicle and is driven by power transferred from the engine 16 through a transaxle or gear box 18, which may be an automatic or a manual gear box, into the front differential 22 of the drive train assembly and finally on through to the power takeoff unit 20. In an all wheel drive vehicle power is delivered to the rear differential 24 via a propeller shaft or driving shaft 26 when there is a demand for it. At the rear differential 24 power is split to a left hand rear side shaft 28 and a right hand rear side shaft 30 for distribution to the wheels at the rear of the vehicle. The front differential 22 splits power and slip or spin from the left hand front side shaft 32 and the right hand front side shaft 34. An all wheel drive vehicle distributes power to both the rear differential 24 and the front differential 22 via a distributing drive. In this all wheel drive vehicle configuration either the front axle or the rear axle 36 is the primary driven axle with the other axle only receiving most of the power 14 when needed. The preferred embodiment of the present invention is an all wheel drive vehicle wherein an active bi-directional overrunning clutch 10 is located within or near the rear differential 24 and acts from there to distribute torque to the rear axle 36 of the vehicle during front wheel spin conditions. However, it should be noted that a primary driven rear axle vehicle may also be used with the active bi-directional overrunning clutch 10 installed at or near the front differential 22 of such a vehicle.

#The drive train of the vehicle 12 shown in FIG. 1 includes a propeller shaft or drive shaft 26 which transmits power from a power take off unit 38 to the rear differential 24. The rear differential drive 24 includes an axle or oil housing 40 which includes a bi-directional overrunning clutch 10 and a differential housing 42 which is supported about a rotational axis. The differential housing is driven by a vehicle gear box via a driving gear. The bi-directional overrunning clutch 10 will connect to the differential housing 42 via a rear pinion shaft 44 and will only transmit driving torque to the rear axle 36 when the front axle 14 or front wheels are in a spin or slip condition. When the gear has been selected, by the operator, into a forward gear and then is placed into a reverse gear or the opposite, i.e., a reverse gear was selected and then a forward gear selected, the bi-directional overrunning clutch of prior art devices can make an engagement noise which occurs when the rotation of the clutch is changed abruptly from a counter clockwise direction to a clockwise direction or from a clockwise direction to a counter clockwise direction. This engagement phenomenon is noticeable to operators of the vehicle and may be reported as being undesirable.