Method and apparatus for cooling a rotor assembly
A rotor assembly includes a rotor core having a rotatable shaft and defining at least one rotor post, and a winding wound around the post that defines a set of rotor winding end turns. A support assembly for the rotor winding end turns is rotatably coupled to the rotatable shaft and defines a cavity in fluid communication with a fluid coolant flow. The rotor winding end turns extend into the cavity.
1 . A support assembly for a set of rotor winding end turns extending from a rotor core of an electrical machine having a rotatable shaft, the support assembly comprising:
a first collar including a first wall having an annular first surface facing an axial end of the rotor core, an opposing annular second surface, and an annular third surface defining a first bore extending from the annular first surface to the annular second surface, the first collar further including an annular second wall coupled to the first wall and extending axially therefrom toward the rotor core arranged to radially overlie the rotor winding end turns, the annular second wall having a radially outward facing annular fourth surface, and an opposing annular fifth surface facing the rotor winding end turns;
a second collar axially disposed between the rotor core and the first collar, including a third wall disposed between the first wall and the rotor winding end turns, the third wall having an annular sixth surface facing the axial end of the rotor core, and an opposing seventh surface, the third wall further including an annular eighth surface defining a second bore, the second collar further including an annular fourth wall coupled to the third wall and extending axially therefrom toward the rotor core and disposed between the rotor winding end turns and the annular second wall; and
a coupling disc including an annular fifth wall facing the axial end of the rotor core, the coupling disc further including an annular sixth wall coupled to the annular fifth wall and extending axially therefrom toward the rotor core and radially underlying the rotor winding end turns, the annular sixth wall circumferentially surrounding and coupled to the rotatable shaft;
wherein the first collar is coupled along the annular third surface to the annular fifth wall at an outer periphery of the coupling disc, and wherein the second collar is coupled to the coupling disc along the annular eighth surface.
2 . The support assembly of claim 1 , wherein the second collar is electrically insulative.
3 . The support assembly of claim 1 , further comprising a support disc defining a fourth bore sized to receive the rotatable shaft therethrough, and a radially outer periphery, the support disc further defining a set of radially extending first slots sized to receive a respective rotor winding axially therein, the support disc coupled to the rotatable shaft at the fourth bore, and disposed axially between the rotor core and the second collar; and
wherein the annular fifth surface of the first collar is coupled to the radially outer periphery of the support disc.
4 . The support assembly of claim 3 , wherein the annular fifth surface of the first collar is coupled to the radially outer periphery of the support disc via an interference fit.
5 . The support assembly of claim 3 , further comprising a coolant distribution ring defining a central fifth bore, and circumferentially surrounding and coupled to the annular sixth wall of the coupling disc, the coolant distribution ring radially disposed between the annular sixth wall and an end turn of the rotor windings.
6 . The support assembly of claim 5 , wherein a cavity is radially defined between the coolant distribution ring and the second collar, and wherein the rotor winding end turns extend into the cavity.
7 . The support assembly of claim 5 , wherein the coolant distribution ring includes a set of radially extending channels defined therethrough in fluid communication with the set of rotor winding end turns.
8 . The support assembly of claim 5 , wherein the annular sixth wall of the coupling disc defines a set of apertures extending radially therethrough in fluid communication with the coolant distribution ring.
9 . The support assembly of claim 5 , wherein the annular fourth wall of the second collar includes a radially inward facing tenth surface defining a set of axially extending grooves, in fluid communication with the coolant distribution ring.
10 . The support assembly of claim 9 , wherein the axially extending grooves define a taper.
11 . The support assembly of claim 9 , wherein the radially inward facing tenth surface further defines a set of circumferentially extending grooves, in fluid communication with the axially extending grooves.
12 . The support assembly of claim 5 , further comprising a spacer disc disposed axially between the support disc and the coolant distribution ring and rotatably coupled to the rotatable shaft, the spacer disc further including a radially outer surface defining a set of radially extending, circumferentially spaced second slots sized to receive a respective rotor winding therein.
13 . The support assembly of claim 12 , wherein the spacer disc is formed from an electrically insulative material.
14 . The support assembly of claim 12 , wherein a respective rotor winding end turn extends through a corresponding second slot.
15 . The support assembly of claim 1 , wherein the coupling disc is coupled to the rotatable shaft via an interference fit.