The Rear Drive Module is a compact, light weight gear box with disconnect clutch for electric motor assisted AWD solutions. The simple interface allows the gear box to be combined with various E-motors technologies. The controlled disconnect clutch allows seamless switching from 4WD to 2WD mode. The gearbox is used in on-demand rear axles driven by an electric motor. The E-motor torque is geared up to axle torque by a two stage reduction gear. When the E-motor is reaching its speed limit or the driver is selecting the 2WD mode, the controlled clutch disconnects the motor from the differential. The low drag torque of the disconnect clutch provides superior fuel efficiency of the E-AWD in 2WD mode.
The majority of rear-wheel drive vehicles have engines mounted at the front. Power produced by the engine is transferred to the rear wheels via the longitudinal propshaft, the differential and the two sideshafts. This system is more complicated than that for front-wheel drive and is widely used in high performance and luxury class cars.
Also known as rotational backlash, this is the amount of angular clearance which can be detected or measured within a geared system. Generally, the lower the backlash, the better for noise, NVH, etc, although a certain amount may be required to compensate for tooth error without gear jamming.
A rubber coupling is suitable when very low running angles (<1°) are required and a level of torsional compliance is required in the driveline system.
See Fixed Ball Joint.