摘要 |
The wrist assembly is provided at the tip of a robot arm (20) and equipped with a wrist (21) which has a pair of parallel protrusions (22,23) at the tip ot it. A second wrist (24) is provided between the protrusions of the first wrist and is supported so as to rotate relative to the protrusions about an axis (B) that meets at right angles with an axis (Y) in the lengthwise direction of the robot arm. A third wrist (25) is supported so as to rotate relative to the second wrist about a second axis (a) that meets at right angles with the first axis (B). The third wrist permits a working attachment to be mounted on the tip of it. A first motor (45) and a second motor (55) are used to drive the second wrist and the third wrist. A power transmission mechanism (I) transmits the driving force of the first motor to the second wrist is provided in one protrusion of the first wrist, and has a first pair of hypoid gears (35,36) that are in mesh with each other. A second power transmission mechanism (II) transmits the driving force of the second motor to the third wrist is provided in the other protrusion of the first wrist, and has a second pair of hypoid gears (51,52) that are in mesh with each other. |