Drive unit for power operated vehicle closure

摘要

A drive unit 20 for a power operated vehicle closure 12 has a track 24, a guide 26 moveable along the track, a link 34 attached to the guide at one end and adapted to be attached to the vehicle closure at the opposite end, and a motor assembly 22 for moving the guide along the track. The motor assembly 22 has an electric motor 36 and a speed reducer driven by the electric motor that has a first stage and a second stage. The first stage includes a belt drive 40, 42, 44 and the second stage is a spur gear set 46, 48. Alternatively the first stage is a worm gear 140 and a mating helical gear 142. The worm gear preferably has a high lead angle and a high number of leads. The speed of the electric motor is reduced to about 1000 rpm or less in the first stage permitting the use of spur gears in the second stage while retaining quiet operation.