摘要 |
A robot arm is supported by a pillar (14) rotatable about a vertical axis (A) and rotated by a reversible electric motor (88). The output shaft (90) of the motor (88) is connected to the pillar (14) by means of a mechanical reduction transmission which comprises a pair of planetary reduction units (62, 64). 7he driving members of both reduction units (62, 64) are fixed angularly to the output shaft (90) of the motor (88). The driven members (68, 70) of both reduction units (62, 64) are fixed angularly to the pillar (14). When the device is in operation, the peripheral rings (72, 74) of both reduction units (62, 64) are fixed to a structure (42) which supports the pillar (14). The angular position of at least one of the peripheal rings (72) is adjustable about the vertical axis (A) relative to the other ring (74) to enable the play in the internal gearings of the reduction units (62, 64) to be cancelled out. |