Electric drive module having motor with heat sink insert in rotor shaft
A motor drive system has a rotor assembly that is rotatable about an axis and includes a hollow shaft, a tube, and one or more fin sets. The tube is received in the shaft and defines a first passage. The fin sets are disposed about the tube and are engaged to the shaft. Each fin set defines a plurality of circumferentially spaced apart fins that are coupled to the shaft and the tube. The first passage is configured to discharge fluid communicated therethrough into a return chamber that is formed in the rotor assembly. A plurality of second passages are formed between the shaft and fins and are in fluid communication with the return chamber.
1. A motor drive system comprising:
an electric motor having a stator and a rotor assembly that is received in the stator and rotatable about a rotational axis, the rotor assembly having a shaft member, a central tube, and a plurality of fin sets, the shaft member defining a cavity and having a shaft wall that is disposed circumferentially about the rotational axis, the cavity extending along the rotational axis and through a first end of the shaft member, the central tube being received in the cavity concentrically with the shaft wall and defining a first flow passage, each of the at least one fin sets being disposed about the central tube and being engaged to the shaft wall, each of the at least one fin sets defining a plurality of circumferentially spaced apart fins, a plurality of inner coupling sections, and a plurality of outer coupling sections, each of the inner coupling sections coupling a corresponding pair of adjacent fins at a radially inner end of the corresponding pair of adjacent fins, each of the outer coupling sections coupling an associated pair of adjacent fins at a radially outer end of the associated pair of adjacent fins;
at least one separator plate having a central aperture and at least one outer aperture, received onto the central tube, in abutment with adjacent fin sets such that a surface of the central aperture contacts an outer surface of the central tube and the outer aperture(s) are disposed inline with circumferential spaces between adjacent fin sets;
wherein the first flow passage is configured to discharge fluid communicated therethrough into a housing, wherein a plurality of second flow passages are formed between the shaft wall and the fins, and wherein the second flow passages are in fluid communication with the housing.
2. The motor drive system of claim 1 , wherein each of the outer apertures has a pair of circumferentially opposite sides that are disposed in a non-parallel manner to adjacent ones of the fin members such that the circumferentially opposite sides cross several of the second flow passages.
3. The motor drive system of claim 1 , wherein each of the separator plates is fixedly coupled to the central tube.
4. The motor drive system of claim 1 , wherein the rotor assembly further comprises a hollow rotor shaft into which the shaft member is received.
5. The motor drive system of claim 1 , wherein a plurality of the fins of each of the at least one fin sets is unitarily and integrally formed of a sheet of a thermally conductive material.
6. The motor drive system of claim 5 , wherein the fins of each of the at least one fin sets are unitarily and integrally formed.
7. The motor drive system of claim 1 , wherein the outer coupling sections engage the shaft wall in a shrink-fit manner.
8. The motor drive system of claim 1 , wherein the central tube and each of the at least one fin sets are formed of aluminum.
9. The motor drive system of claim 1 , wherein the inner coupling sections are brazed to the central tube.
10. The motor drive system of claim 1 , wherein the inner heat exchanger tube and each of the fin sets are formed of aluminum.
11. A motor drive system comprising:
an electric motor having a stator and a rotor assembly that is received in the stator and rotatable about a rotational axis, the rotor assembly being rotatable about a rotational axis relative to the stator and having a rotor shaft, an outer heat exchanger tube, an inner heat exchanger tube, a plurality of fin sets and a plurality of plate members, the outer heat exchanger tube being received into a first end of the rotor shaft such that an outer surface of the outer heat exchanger tube engages an inside surface of the rotor shaft, the outer heat exchanger tube defining a cavity and having a tube wall that is disposed circumferentially about the rotational axis, the inner heat exchanger tube being received in the cavity concentrically with the tube wall and defining a first flow passage, each of the fin sets being disposed about the central tube and being engaged to the tube wall, each of the fin sets defining a plurality of circumferentially spaced apart fins, a plurality of inner coupling sections, and a plurality of outer coupling sections, each of the inner coupling sections coupling a corresponding pair of adjacent fins at a radially inner end of the corresponding pair of adjacent fins, each of the outer coupling sections coupling an associated pair of adjacent fins at a radially outer end of the associated pair of adjacent fins, each of the plate members being mounted to the inner heat exchanger tube and abutting an axial end of at least one of the fin sets;
wherein the cavity terminates within the rotor shaft such that a second end of the rotor shaft that is opposite the first end is closed,
wherein the first flow passage is configured to discharge fluid communicated therethrough into a chamber that is located along the rotational axis between the inner heat exchanger tube and the second end, and wherein the second flow passages are in fluid communication with the chamber and are configured to conduct fluid from the chamber through an opening in the first end of the rotor shaft.
12. The motor drive system of claim 11 , wherein each plate member has a central aperture through which the inner heat exchanger tube extends, and a plurality of outer apertures that are disposed radially outward from and circumferentially spaced apart about the central aperture.
13. The motor drive system of claim 12 , wherein each of the outer apertures has a pair of circumferentially opposite sides that are disposed in a non-parallel manner to adjacent ones of the fin members such that the circumferentially opposite sides cross several of the second flow passages.
14. The motor drive system of claim 11 , wherein a plurality of the fins of each of the fin sets is unitarily and integrally formed of a sheet of a thermally conductive material.
15. The motor drive system of claim 14 , wherein the fins of each of the fin sets are unitarily and integrally formed.
16. The motor drive system of claim 11 , wherein the outer coupling sections engage the tube wall in a shrink-fit manner.
17. The motor drive system of claim 11 , wherein the inner coupling sections are brazed to the inner heat exchanger tube.