Abstract: A drive apparatus for an electric bike includes a hollow housing body, an internal ring gear fixed to the housing body, and a main shaft. At least two motor units are mounted in the housing body. Each motor unit includes a support bracket and a number of motors mounted on the support bracket. Each motor drives the internal gear through a transmission mechanism to rotate the housing body about the main shaft. The motors share one controller. Peaks of the motor cogging torque can be staggered.

Abstract: A drive unit includes an electric motor, a worm shaft coupled to the motor, a worm gear engaging with the worm shaft, and an output shaft connected to the worm gear. The motor has a motor shaft on which the worm shaft is fixed. The worm shaft is made of plastic. The drive unit further includes a metallic sleeve press fitted to the motor shaft. An outer profile of the sleeve is non-circular. A correspondingly shaped receiving hole is formed in the worm shaft to receive the sleeve. The sleeve rotates with the motor shaft and drives the worm shaft.

Abstract: A drive apparatus for an electric bike includes a hollow housing body, an internal ring gear fixed to the housing body, and a main shaft. At least two motor units are mounted in the housing body. Each motor unit includes a support bracket and a number of motors mounted on the support bracket. Each motor drives the internal gear through a transmission mechanism to rotate the housing body about the main shaft. The motors share one controller. Peaks of the motor cogging torque can be staggered.

Abstract: The planetary gear train includes a first sun gear driven by the motor, a first ring gear, a first carrier, and a plurality of first planetary gears arranged at one side of the first carrier and meshing with the first sun gear and the first ring gear. The first sun gear, first planetary gears and first ring gear are helical gears so that meshing surface is increased. Helical teeth formed on an inner surface of the first ring gear mesh with the helical teeth of the first planetary gears. Therefore, the operation is stable and the noise is low. The planetary gears are made of plastic to further decrease the noise. The first ring gear is made by sintered powder metallurgy.

Abstract: The planetary gear train includes a first sun gear driven by the motor, a first ring gear, a first carrier, and a plurality of first planetary gears arranged at one side of the first carrier and meshing with the first sun gear and the first ring gear. The first sun gear, first planetary gears and first ring gear are helical gears so that meshing surface is increased. Helical teeth formed on an inner surface of the first ring gear mesh with the helical teeth of the first planetary gears. Therefore, the operation is stable and the noise is low. The planetary gears are made of plastic to further decrease the noise. The first ring gear is made by sintered powder metallurgy.