Lineartriebwerk mit Selbstantrieb

摘要

A linear motion drive apparatus (10) uses a friction drive wheel (50) to drive a carriage (12) along two rails (14, 16). The drive shaft (30) of the friction wheel (50) is supported by the carriage (12), and has a rotor (48) of a pancake motor (36) and an inertia wheel (54) non-rotatably attached thereto. The stator (48) is fixed to a wall (18) of the carriage (12). The carriage is supported by recirculating ball bearings (22) which are arranged with permanent magnets (60, 62) to urge the friction wheel (50) into engagement with a flat rail (16). A slip detection and correction system has first encoder (90) mounted on the drive shaft (30) to produce a signal (300) representing the rotational position of the shaft, and a second encoder (94) mounted on the carriage to produce a signal (312) representing the position of the carriage (12) with respect to the rails (14, 16). The motor (36) is responsive to the signals (300, 312) to compensate for detected slippage.