Patent ID: 8584548

Claim:
A robot arm assembly comprising a first link rotatably connected to a second link by a joint, comprising: an actuator mounted in the first link; a harmonic drive for rotating the second link, the harmonic drive comprising a wave generator, a flex spline, and a circular spline, the flex spline fitting over the wave generator, and the circular spline engaging the flex spline, the flex spline being fixed to the first link, the circular spline being fixed to the second link; a belt drive between the actuator and the harmonic drive, and defining a first passage; a support base received in the first link and employed to support the belt drive, the support base provided with a bearing mounted therein; and a sleeve extending through the first and the second link; wherein the belt drive transmits the rotational movement from the actuator to the wave generator, the wave generator defines a second passage communicating with the first passage of the belt drive, the first and second passages cooperatively define a conduit, the sleeve comprises a tube and a rim radially extending from the tube, the rim is fixed to the second link, the tube is received in the conduit, and an end of the tube away from the rim extends out of the conduit and is rotatably received in the support base via the bearing.