Linear type actuator

Abstract

In order to reduce cost through reduction in material cost and improvement of productivity, in a linear type actuator comprising: a stator unit having coils consisting of wound magnet wires and housed inside stator sub-assemblies and pole teeth arranged on the inner circumference thereof; a rotor unit having a field magnet arranged on the outer circumference thereof and rotatably disposed so as to oppose the pole teeth with a given gap; an output shaft attached to a center portion of the rotor unit and movable in the axial direction thereof; and converting means provided on the innermost diametral circumferential surface of the rotor unit and adapted to convert rotary motion of the rotor unit into linear motion of the output shaft, the converting means is made of a material different from that of the rotor unit.

What is claimed is:  
     
         1 . A linear type actuator comprising: 
 a stator unit having coils consisting of wound magnet wires and housed inside stator sub-assemblies and pole teeth arranged on an inner circumference thereof;    a rotor unit having a field magnet arranged on an outer circumference thereof and rotatably disposed so as to oppose said pole teeth with a given gap;    an output shaft attached to a center portion of said rotor unit and movable in the axial direction thereof; and    converting means provided on an innermost diametral circumferential surface of said rotor unit and adapted to convert rotary motion of said rotor unit into linear motion of said output shaft,    wherein said converting means is made of a material different from that of said rotor unit.    
     
     
         2 . The linear type actuator as set forth in  claim 1 , wherein said converting means is configured with a plurality of straight sides and has corners thereof rounded.  
     
     
         3 . The linear type actuator as set forth in  claim 1 , wherein said rotor unit is integrally constituted by insert molding said field magnet, magnet stoppers adapted to hold said field magnet and also to protect end corners thereof, and said conversion means.