Patent Application
20140093398
Exemplary embodiments pertain to the art of electric machines and, more particularly, to an electric machine including a shaft having a pump vane.
Electric machines generally include a housing that encloses a rotor and a stator. The rotor typically includes a rotor hub. The rotor hub supports a plurality of rotor windings that, when acted upon by a magnetic field generated by the stator, cause the rotor to rotate. In some cases, the rotor will include laminations that support permanent magnets. The permanent magnets also interact with the magnetic field supplied by the stator causing the rotor to rotate. The rotor hub is joined to a shaft that is supported by one or more bearings. In some cases, a coolant is introduced into the housing to exchange heat with the rotor, stator and/or other internal components. Coolant may be supplied by an external pump that guides a liquid coolant into and out from the housing. In other cases, the electric machine may include an integral pump that is connected to and driven by the shaft.
Disclosed is an electric machine including an electric machine housing having a first end, a second end, and an interior. A stator is fixedly mounted relative to the electric machine housing. A pump housing is provided at one of the first and second ends. A rotor is rotatably supported relative to the stator. The rotor includes a shaft having a first end that extends to a second end through an uninterrupted intermediate portion having an outer surface. One of the first and second ends extends into the pump housing. At least one vane element projects from the outer surface and is arranged in the pump housing.
Also disclosed is a method of pumping liquid in an electric machine. The method includes driving a rotor shaft having a first end that extends to a second end through an uninterrupted intermediate portion having an outer surface, rotating at least one vane element projecting outward from the outer surface in a pump housing provided in an electric machine housing, generating a fluid pressure in the pump housing, and urging the fluid from the pump housing.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
An electric machine in accordance with an exemplary embodiment is indicated generally at 2 in
Housing 4 is shown to include a liquid pump 24 coupled to first end wall 8. Liquid pump 24 is configured to create a pressurized flow of liquid within interior portion 14. For example, liquid pump 24 may generate a flow of coolant such as oil, glycol, or the like within housing 4. Liquid pump 24 includes a pump housing 27 having an inner wall 30. Inner wall 30 defines a pump chamber 32 having a center axis 33. Inner wall 30 is also shown to include an outlet 34 and an inlet 35 that fluidically connects pump chamber 32 and interior portion 14. Pump housing 27 includes a cover 36 that fluidically seals pump chamber 32.
Electric machine 2 is also shown to include a stator 40 arranged on inner surface 17. Stator 40 includes a body or stator core 42 that supports a plurality of stator windings 44 having a first end turn portion 46 and a second end turn portion 47. A rotor assembly 54 is rotatably mounted to housing 4 relative to stator 40. Rotor assembly 54 includes a rotor hub 57 that supports a plurality of rotor laminations 59. Rotor laminations 59 include permanent magnets (not shown). Rotor assembly 54 may alternatively be provided with a rotor core and rotor windings. Rotor hub 57 is coupled to a rotor shaft 62. Rotor shaft 62 is supported to housing 4 through a first bearing 64 provided on first end wall 8 and a second bearing 65 provided on second end wall 12. Rotor shaft 62 includes a first end portion 68 that extends to a second end portion 69 through an uninterrupted intermediate portion 71. The term “uninterrupted” should be construed to describe a rotor shaft that is materially integral from the first end to the second end. “Materially integral” should be understood to mean that intermediate portion 71 is devoid of connections, couplings or the like. Rotor shaft 62 includes a shaft axis 74 that is off-set relative to center axis 33 of pump chamber 32.
In accordance with an aspect of the exemplary embodiment illustrated in
In accordance with another aspect of an exemplary embodiment illustrated in
At this point it should be understood that the exemplary embodiments describe an electric machine including a housing having an integral pump. The integral pump guides liquid, such as coolant into a housing. The coolant flow is generated by one or more vane elements that are provided in a materially integral, uninterrupted shaft. It should also be understood that the arrangement of vane elements may vary. In addition to the vane elements depicted in
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.
