Stator heat transfer feature for a dynamoelectric machine
A dynamoelectric machine includes a shaft, a rotor radially outward from the shaft with the rotor and shaft arranged to rotate in unison, a stator radially outward from the rotor with the stator being stationary relative to the rotor and shaft, and a heat transfer feature adjacent to and radially outward from the stator. The heat transfer feature includes a base encasing the stator, the base having a first end, a second end, and an axial middle; a first set of fins extending radially outward from the base adjacent the first end and the second end; and a second set of fins extending radially outward from the axial middle of the base with the second set of fins each having a smaller surface area and being closer to one another than the first set of fins.
1. A dynamoelectric machine comprising:
a shaft extending along an axis;
a rotor radially outward from and coupled to the shaft, the rotor and shaft arranged to rotate in unison about the axis;
a stator radially outward from the rotor, the stator being rotationally uncoupled from the shaft and rotor and disposed to remain stationary relative to the rotor and shaft; and
a heat transfer feature adjacent to and radially outward from the stator, the heat transfer feature comprising:
a base encasing the stator, the base extending axially from a first end to a second end and having an axial middle disposed therebetween;
a first set of fins extending radially outward from the base adjacent the first end and the second end; and
a second set of fins extending radially outward from the axial middle of the base with the second set of fins each having a smaller surface area and being closer to one another than the first set of fins;
wherein axially adjacent fins of the second set of fins are circumferentially offset.
2. The dynamoelectric machine of claim 1 , wherein the first set of fins includes at least two axial rows of fins adjacent the first end and two axial rows of fins adjacent the second end.
3. The dynamoelectric machine of claim 1 , further comprising:
a housing radially outward from the heat transfer feature.
4. The dynamoelectric machine of claim 3 , further comprising:
a fluid inlet in the housing that allows a fluid to enter a gap between the heat transfer feature and the housing; and
a fluid outlet in the housing that allows the fluid to exit the gap.
5. The dynamoelectric machine of claim 1 , further comprising:
a header that fluidically isolates the heat transfer feature and the housing from the shaft, the rotor, and the stator.
6. The dynamoelectric machine of claim 1 , further comprising:
an interface layer between the stator and the heat transfer feature, the interface layer fluidically separating the stator from the heat transfer feature.
7. The dynamoelectric machine of claim 1 , wherein the stator is a lamination stack.
8. The dynamoelectric machine of claim 1 , further comprising:
a cooling lubricant adjacent to the heat transfer feature.
9. The dynamoelectric machine of claim 8 , wherein the heat transfer feature fluidically isolates the stator from the cooling lubricant.
10. The dynamoelectric machine of claim 1 , wherein each of the second set of fins extends axially along the base for one-tenth or less of a total axial length of the base.
11. The dynamoelectric machine of claim 1 , wherein the second set of fins include at least three axial rows of fins.
12. The dynamoelectric machine of claim 1 , wherein the first set of fins extends radially outward a greater distance than the second set of fins.
13. The dynamoelectric machine of claim 1 , wherein the first set of fins and the second set of fins are each oval shaped when viewed in a radial direction.
14. The dynamoelectric machine of claim 13 , wherein the oval shape of the first set of fins and the second set of fins is elongated in a substantially axial direction.
15. The dynamoelectric machine of claim 1 , wherein axially adjacent fins of the first set of fins are circumferentially offset.