US 11,837,943 B2
Rotor air cooling system
Emil Håkansson, Gothenburg (SE); Johan Brunberg, Molndal (SE); and Johan Andersson, Gothenburg (SE)
Assigned to Volvo Car Corporation, Gothenburg (SE)
Filed by Volvo Car Corporation, Gothenburg (SE)
Filed on Nov. 24, 2020, as Appl. No. 17/103,200.
Claims priority of application No. 19218519 (EP), filed on Dec. 20, 2019.
Prior Publication US 2021/0194324 A1, Jun. 24, 2021
Int. Cl. H02K 5/20 (2006.01); H02K 9/06 (2006.01); H02K 1/32 (2006.01)
CPC H02K 9/06 (2013.01) [H02K 1/32 (2013.01); H02K 5/20 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A rotor air cooling system, comprising:
an outer housing;
an inner housing configured to be inserted into the outer housing, the inner housing comprising an open backend;
a stator attached to an interior side of the inner housing;
a main rotor body comprised in the inner housing, the main rotor body being arranged around a rotor shaft arranged to extend through the inner housing and the outer housing, wherein cooling air axially enters the main rotor body in an inlet end via the open backend of the inner housing, passes through cavities of the main rotor body, and exits the main rotor body in an outlet end;
a water jacket arranged between the inner housing and the outer housing, the water jacket axially extending between a first flange and a second flange formed by and protruding radially from the inner housing to abut an inner surface of the outer housing when the inner housing is inserted into the outer housing, the inner housing comprising one or more spiral-shaped ribs formed by and protruding radially from the inner housing between the first flange and the second flange, the one or more spiral-shaped ribs protruding into the water jacket towards the inner surface of the outer housing less than the first flange and the second flange and not abutting the inner surface of the outer housing when the inner housing is inserted into the outer housing;
a heat exchanger for dissipating heat from the cooling air exiting the main rotor body;
wherein the air exiting the main rotor body is radially guided, via an air outlet of the inner housing being aligned with an air outlet of the outer housing, through the heat exchanger before being arranged to be radially guided via an air inlet of the outer housing being in fluid communication with the open backend of the inner housing to the air inlet of the main rotor body for recirculation of the cooled air through the main rotor body; and
one or more of:
an input endplate arranged around the rotor shaft at the inlet end of the main rotor body, the input endplate comprising through-holes aligned with the through-holes at the inlet end of the main rotor body forming the cavities; and
an impeller arranged on and around the rotor shaft at an outlet end of the main rotor body to facilitate radial guiding of the cooling air exiting the main rotor body at the outlet end.