Patent attributes
An electronically commutated internal rotor motor (20) has an outer stator (28) and a permanent magnet rotor (36) arranged rotatably therein by means of a shaft (40) supported at its drive end (42) by a rotary bearing (54) located in the A-side bell (26) and supported at its other end (44) by a rotary bearing (72) located in the B-side bell (66). The rotary bearing (54) in the A-side bell is preferably so configured that it permits a small radial movement (56) of the drive end (42) relative to this bell (26). The rotary bearing (72) in the B-side bell (66) has its outer race (72) tensioned against a shoulder (90, 94). Its inner race (74) is tensioned between a shoulder (78) of the shaft (40) and a shaped part of non-ferromagnetic material. This shaped part is pressed by a countersunk screw (82), screwed into a threaded bore (84) of the other shaft end (44), against the inner race.