US 12,191,751 B2
Electric motor having improved cooling
Jochen Häfner, Blaufelden (DE); Werner Müller, Mulfingen-Seidelklingen (DE); Stephan Nadig, Zweiflingen-Pfahlbach (DE); Erich Pollok, Niederstten (DE); Gerhard Sturm, Mulfingen (DE); and Martin Baun, Mulfingen (DE)
Assigned to ebm-papst Mulfingen GmbH & Co. KG, Mulfingen (DE)
Filed by EBM-PAPST MULFINGEN GMBH & CO. KG, Mulfingen (DE)
Filed on Aug. 4, 2022, as Appl. No. 17/881,054.
Claims priority of application No. 10 2021 120 672.3 (DE), filed on Aug. 9, 2021.
Prior Publication US 2023/0043968 A1, Feb. 9, 2023
Int. Cl. H02K 5/20 (2006.01); H02K 5/22 (2006.01); H02K 9/06 (2006.01)
CPC H02K 9/06 (2013.01) [H02K 5/207 (2021.01); H02K 5/225 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An electric motor, in particular an external rotor motor, comprises:
a stator with a stator core, a non-rotatably mounted shaft, that extends in the axial direction (A) of the motor, and a rotor bell arranged rotatably with respect to the non-rotatable shaft;
the rotor bell incudes cooling blades in an open, spoke-like design, the rotor bell is rotatably mounted on the shaft by at least one first stator-side bearing shield;
a cooling device is arranged between and connects the shaft and the stator core, the cooling device has a plurality of axial flow openings arranged in the circumferential direction that causes cooling when the motor rotates during operation;
the cooling device has an inner ring connecting the shaft and an outer ring connecting the stator core, and web-shaped connecting portions, extending in the radial direction, are formed integrally with the inner ring and the outer ring; and
the connecting portions have a central middle portion that is wider in the circumferential direction compared to the width in the adjacent web portions adjoining the middle portion on both sides.