US 11,973,374 B2
Outer rotor brushless motor having an axial fan
John B. Fogle, White Hall, MD (US); Dustin Jeffries, Baltimore, MD (US); Michael R. Marjomaa, Mount Wolfe, PA (US); Kevin L. Pulley, White Marsh, MD (US); Vincent W. Zou, Lutherville-Timonium, MD (US); Jarrett A. Dunston, Bel Air, MD (US); David J. Smith, Columbia, MD (US); Rene Thieme, Riesa (DE); Tim Heimrich, Bad Camberg (DE); Tobias Heep, Hadamar-Steinbach (DE); Daniel Bernhart, Bad Camberg (DE); and Dieter Schmidtfrerick, Idstein (DE)
Assigned to Black & Decker Inc., New Britain, CT (US)
Filed by Black & Decker Inc., New Britain, CT (US)
Filed on Apr. 23, 2020, as Appl. No. 16/856,737.
Claims priority of provisional application 62/881,105, filed on Jul. 31, 2019.
Claims priority of provisional application 62/837,935, filed on Apr. 24, 2019.
Prior Publication US 2020/0343789 A1, Oct. 29, 2020
Int. Cl. H02K 1/27 (2022.01); B25F 5/02 (2006.01); H02K 1/2786 (2022.01); H02K 1/28 (2006.01); H02K 3/52 (2006.01); H02K 5/15 (2006.01); H02K 5/16 (2006.01); H02K 7/14 (2006.01); H02K 9/06 (2006.01); H02K 11/33 (2016.01); H02K 15/03 (2006.01); H02K 21/22 (2006.01); H02K 29/08 (2006.01)
CPC H02K 1/2786 (2013.01) [B25F 5/02 (2013.01); H02K 1/28 (2013.01); H02K 3/522 (2013.01); H02K 5/15 (2013.01); H02K 5/16 (2013.01); H02K 5/161 (2013.01); H02K 7/14 (2013.01); H02K 7/145 (2013.01); H02K 9/06 (2013.01); H02K 11/33 (2016.01); H02K 15/03 (2013.01); H02K 21/22 (2013.01); H02K 29/08 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A brushless direct-current (BLDC) motor comprising:
a stator having a stator core, a plurality of teeth extending radially outwardly from the stator core, and a plurality of windings wound around the stator teeth;
a rotor shaft extending along a center axis;
a rotor having a rotor core disposed around the stator, a plurality of permanent magnets secured to the rotor core, an inner annular member mounted on the rotor shaft, and a plurality of radial blades extending angularly from the rotor core to the inner annular member forming a fan adjacent the stator that generates an airflow with rotation of the rotor shaft;
a first end cap including a radial back plate proximate the fan and a center opening in the radial back plate through which the rotor shaft extends, the radial back plate including at least one sloped surface forming at least one air gap, wherein the airflow generated by the fan is centrifugally guided within the first end cap by the at least one sloped surface and caused to exit the first end cap through the at least one air gap; and
a second end cap including a main body disposed adjacent the stator opposite the fan.