Self-propelled linear motion drive apparatus

摘要

A linear motion drive apparatus uses a friction drive wheel to drive a carriage along two rails. The drive shaft of the friction wheel is supported by the carriage, and has a rotor of a pancake motor and an inertia wheel non-rotatably attached thereto. The stator is fixed to a wall of the carriage. The carriage is supported by recirculating ball bearings which are arranged with permanent magnets to urge the friction wheel into engagement with the flat rail. A slip detection and correction system has first encoder mounted on the drive shaft to produce a signal representing the rotational position of the shaft, and a second encoder mounted on the carriage to produce a signal representing the position of the carriage with respect to the rails. The motor is responsive to the signals to compensate for detected slippage.