Power tool having an electronically commutated motor and double insulation

Abstract

A power tool has a housing a housing having an electronically commutated motor disposed therein. The motor has a rotor and a stator. The rotor has permanent magnets. The stator has a lamination stack and windings wound therein. Features are provided to provide double insulation.

1 . A power tool, comprising:
 a housing having an electronically commutated motor disposed therein;   the motor having a rotor and a stator, the rotor having permanent magnets, the stator having a lamination stack and windings wound therein;   the rotor overmolded with an overmold of material that is electrically insulative, the overmold including a sense magnet tray formed therein when the overmold material is molded, the overmold material surrounding the permanent magnets and affixed them in place; and   a sense magnet tray received in the sense magnet tray.   
     
     
         2 . The apparatus of  claim 1  wherein the electrically insulative material is an electrically insulative thermoplastic. 
     
     
         3 . The apparatus of  claim 1  wherein the electrically insulative material is an electrically insulative thermoset. 
     
     
         4 . The apparatus of  claim 1  wherein the overmold includes features formed therein during molding that receive balancing material. 
     
     
         5 . The apparatus of  claim 1  including a yoke of ferromagnetic material disposed in the sense tray, the sense magnet disposed on top of the yoke, the sense magnet made of ferrite.