Abstract: Hollow shaft reduction gear with overload protecting device facilitating adjusting the torque of the overload protecting device and repairing the device. A drive plate (8) is axially slidably mounted on one end portion of a hollow output shaft (2) projecting outside from a gear case (1). The drive plate is restrained from rotation relative to the hollow output shaft (2). A driven plate (11) is fixedly mounted on one end portion of a driven shaft (7) projecting from the extremity of the end portion of the hollow output shaft (2) so as to confront the drive plate (8). An interlocking recess (13) and a holding recess (14) are formed in the confronting surfaces of the drive plate (8) and the driven plate (11) respectively, and a ball 15 is held between the recesses (13, 14). The drive plate (8) is biased toward the driven plate (11) by a spring (16).

Abstract: A system for coupling a motor with a worm speed reducer in which the work hours for assembling the worm speed reducer to the motor can be reduced, and the size and the weight of the reducer can also be minimized. A side of the worm speed reducer case 2 coupled to the motor case 1 is made to comprise an open face and through the open face, a worm gear G is installed inside the speed reducer case 2. A worm W is formed on the circumference of a projected free end of a motor spindle 7 and the bearings for the motor spindle 7 are mounted in a motor case flange 9. The open face of the speed reducer is covered with the flange 9 and the reducer case and the flange 9 are firmly clamped by bolts, thus releasably coupling the motor to the speed reducer.