Patent ID: 8037853
Filing Date: 2011-10-18
Classification: F01L

Abstract:
1. A linear actuator comprising: a stationary permanent magnet assembly having at least one permanent magnet for generating a permanent magnetic field; a movable coil assembly having at least one coil of electrically conductive material for generating a temporary magnetic field to thereby move the movable coil assembly with respect to the stationary permanent magnet assembly, the movable coil assembly surrounding the stationary permanent magnet assembly; and a heat transfer unit surrounding at least a portion of the movable coil assembly for removing heat generated by the at least one coil during operation, the heat transfer unit comprising a wall with an internal cavity, an inlet port in fluid communication with the internal cavity and an outlet port in fluid communication with the internal cavity and spaced from the outlet port so that cooling liquid can be circulated through the internal cavity between the inlet and outlet ports; an upper magnet support portion rigidly connected to an upper end of the heat transfer unit and a lower magnet support portion rigidly connected to a lower end of the heat transfer unit with the stationary permanent magnet assembly being rigidly connected to the upper and lower magnet supports; and an upper coil suspension member extending between the upper magnet support portion and an upper end of the movable coil assembly, and a lower coil suspension member extending between the lower magnet support portion and a lower end of the movable coil assembly.