Patent ID: 7445576

Claim:
A machine tool planetary transmission, the planetary transmission comprising: a drive shaft ( 1 ) connected to a sun gear ( 2 ); an output shaft ( 3 ) connected to a planetary carrier ( 10 ); an internal gear ( 4 ) which, in a first operating position, being coupled to a housing and, in a second operating position, being coupled to the sun gear; a hub ( 6 ) concentrically surrounding the drive shaft ( 1 ); a sliding collar ( 5 ) concentrically surrounding the hub ( 6 ) and being axially movable over and with respect to the internal gear ( 4 ); in the first operating position, the sliding collar ( 5 ) couples the internal gear ( 4 ) to the housing ( 12 ), and, in a second operating position, the sliding collar ( 5 ) couples the internal gear ( 4 ) to the hub ( 6 ), wherein an end of the sliding collar ( 5 ), remote from the internal gear ( 4 ), has an integral centering bore ( 7 ) which is concentric with the hub ( 6 ), the hub ( 6 ) includes a centering collar ( 8 ) which is concentric with an axis of the hub ( 6 ) and located along the axis of the hub ( 6 ) so that the centering bore ( 7 ) of the sliding collar ( 5 ) concentrically surrounds and engages with the centering collar ( 8 ) when a locking arrangement of the sliding collar ( 5 ) engages with a mating locking arrangement of the hub ( 6 ) in the second operating position, and a largest diameter portion of the hub ( 6 ) includes the centering collar ( 8 ), an external tooth locking arrangement is located adjacent the centering collar ( 8 ), and the sliding collar ( 5 ) engages, upon movement of the sliding collar ( 5 ) to the second position, both the external tooth locking arrangement and the centering collar ( 8 ).