ELECTRIC MACHINE INCLUDING AN ADAPTABLE COOLING SYSTEM

An electric machine includes a housing having an outer surface and an inner surface. A stator is fixedly mounted to the inner surface. The stator includes a stator core, and a plurality of windings supported by the stator core. The plurality of windings includes first and second end turn portions. A rotor is rotatably mounted within the housing. An adaptable cooling system is fluidically connected to the housing. The adaptable cooling system includes a first coolant circuit configured to guide coolant in a heat exchange relationship with the stator core, and a second coolant circuit configured to guide coolant in a heat exchange relationship with the at least one end turn portion. At least one flow controller is configured and disposed to selectively adapt coolant delivery through the first and second coolant circuits based on coolant temperature flowing from the stator.

DETAILED DESCRIPTION OF THE INVENTION

An electric machine in accordance with an exemplary embodiment is indicated generally at2in the FIGURE. Electric machine2is shown in the form of an electric motor having a housing4including an outer surface6and an inner surface8that defines an interior portion9. Housing4also includes a first end wall10and an opposing, second end wall12. At least one of end walls10and12may be removable to provide access to interior portion9. Electric machine2is also shown to include a stator20arranged in interior portion9. Stator20includes a stator core24fixedly mounted to interior surface8. Stator core24supports a plurality of stator windings28that include a first end turn portion30and a second end turn portion32.

Electric machine2is also shown to include a rotor assembly40including a rotor44supported by a shaft50. Rotor44can take on a variety of forms and many include windings and/or permanent magnets. Shaft50includes a first end52supported at first end wall10through a first bearing54, and a second end56supported at second end wall12through a second bearing58. It should be understood that rotor assembly40should not be limited to being supported at both ends of shaft50. Rotor44may also be supported in a cantilevered fashion from one of first and second end walls10and12. Electric machine2is also shown to include a terminal block64that provides an interface between windings28and external electrical sources or loads.

In accordance with an exemplary embodiment electric machine2includes an adaptive cooling system160. Adaptive cooling system160includes a first coolant circuit162, a second coolant circuit164, a third coolant circuit166and a fourth coolant circuit168. First coolant circuit162includes a first inlet portion172that passes coolant in a heat exchange relationship with stator core24and a first outlet section174that guides the coolant from housing4. Second coolant circuit164includes a second inlet portion176that passes coolant in a heat exchange relationship with first end turn portion30and a second outlet section178that guides coolant from housing4. Third coolant circuit166includes a third inlet portion180that passes coolant in a heat exchange relationship with second end turn portion32and a third outlet section182that guides the coolant from housing4. Fourth coolant circuit168includes an fourth inlet portion184fluidically connected to rotor44and a fourth outlet section186that is fluidically connected to housing4. Adaptive cooling system160is also shown to include an inlet190fluidically connected to first, second, third and fourth inlet portions172,176,180and184. Inlet190is also fluidically connected to a coolant pump194. An outlet196is fluidically connected to first, second, third and fourth outlet sections174,178,182and186.

In accordance with an aspect of the exemplary embodiment, adaptive cooling system160includes a first flow controller204arranged in first outlet section174, a second flow controller206arranged in second outlet section portion178, a third flow controller208arranged in third outlet section182and a fourth flow controller210arranged in fourth outlet section186. First flow controller204is shown in the form of a first thermostatic valve214, second flow controller206is shown in the form of a second thermostatic valve216, third flow controller208is shown in the form of a third thermostatic valve218and fourth flow controller210is shown in the form of a fourth thermostatic valve220. First, second, third and fourth flow controllers204,206,208and210control coolant flow based on temperatures of coolant flowing through each thermostatic valve214,216,218and220.

First thermostatic valve214responds to changes in temperature of coolant flowing through first outlet section174. Similarly, second thermostatic valve216responds to changes in temperature of coolant flowing through second outlet section178, third thermostatic valve218responds to changes in temperature of coolant flowing through third outlet section182and fourth thermostatic valve220responds to changes in temperature of coolant flowing through fourth outlet section186.

With this arrangement, a constant flow of coolant is passed through first inlet portion172, second inlet portion176, third inlet section180and fourth inlet section184. If a temperature of coolant flowing through one or more of first, second, third and/or fourth outlet sections174,178,182and186increases, a corresponding one of thermostatic valves214,216,218and220opens proportionally allowing for an increase in coolant flow. As the temperature of the coolant flowing through the one or more of first, second, third and/or fourth outlet sections174,178,182and186decreases, the corresponding one of thermostatic valves214,216,218and220closes proportionally to reduce coolant flow. In this manner, coolant flow can be adapted to selectively address temperature conditions at stator core24, first and second end turn portions30and32, and/or rotor44