Patent · US Active

Rotor assembly for brushless motor for a power tool

US9450472B2 · kind B2 · utility

20Cited by
71References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 14, 2011
Grant dateSep 20, 2016
Priority date
Expiry dateMar 7, 2033

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02K2203/09
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A power tool includes a brushless DC motor having a stator assembly and a rotor assembly at least a portion of which is arranged pivotably inside the stator assembly. The rotor assembly includes a rotor lamination stack housing a permanent magnets and a rotor fixedly housed inside a center portion of the lamination stack to pivot therewith. A fan may be fixedly attached to the rotor and arranged adjacent the stator assembly. The fan includes a back plate and blades longitudinally projecting from a periphery of the back plate towards the stator assembly, where a middle portion of the back plate is contoured away from an end cap of the motor to accommodate a projecting portion of the end cap. The permanent magnets may extend beyond the longitudinal length of the rotor lamination stack towards a magnet sensor to facilitate sensing of the permanent magnet via the magnet sensor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.