US 11,757,330 B2
Canned outer-rotor brushless motor for a power tool
Dustin Jefferies, Baltimore, MD (US); Marcus E. E. Rydin, Towson, MD (US); Jarrett A. Dunston, Bel Air, MD (US); Timothy W. French, Hampstead, MD (US); Gale A. Heslop, Carney, MD (US); and Ross A. Billings, Reisterstown, MD (US)
Assigned to BLACK & DECKER, INC., New Britain, CT (US)
Filed by Black & Decker Inc., New Britain, CT (US)
Filed on Dec. 17, 2020, as Appl. No. 17/125,031.
Claims priority of provisional application 62/950,562, filed on Dec. 19, 2019.
Prior Publication US 2021/0194321 A1, Jun. 24, 2021
Int. Cl. H02K 7/14 (2006.01); H02K 1/16 (2006.01); H02K 5/173 (2006.01); H02K 1/2791 (2022.01)
CPC H02K 7/145 (2013.01) [H02K 1/16 (2013.01); H02K 1/2791 (2022.01); H02K 5/1735 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A brushless direct-current (BLDC) motor comprising:
a rotor shaft on which a rear motor bearing and a front motor bearing are mounted;
a motor housing through which the rotor shaft extends and including a substantially cylindrical body having an open end and a radial wall opposite the open end, the radial wall forming a first bearing pocket arranged to receive the front motor bearing therein;
a stator assembly including a stator core having an aperture extending therethrough, a plurality of stator teeth radially extending outwardly from the stator core and defining a plurality of slots therebetween, and a plurality of stator windings wound around the plurality of stator teeth;
a stator mount including a radial member coupled to the open end of the motor housing, an elongated cylindrical member projecting axially from the radial member into the aperture of the stator core, a hollow portion extending through a length of the elongated cylindrical member through which the rotor shaft extends, and a second bearing pocket formed in the radial member supporting the rear motor bearing;
an outer rotor comprising a cylindrical rotor core supporting at least one permanent magnet around an outer surface of the stator core;
a rotor mount including an outer rim arranged to couple to the outer rotor, a radial wall extending inwardly from the outer rim, and an inner body mounted on the rotor shaft; and
a positional sensor board mounted on the stator assembly adjacent the stator mount, the positional sensor board comprising at least one magnetic sensor positioned to magnetically sense the at least one permanent magnet of the rotor,
wherein the elongated cylindrical member of the stator mount includes a stepped portion between the stator core and the second bearing pocket, and the positional sensor board is radially aligned with the stepped portion.