Liquid Cooled Electric Motor

Abstract

A liquid-cooled, radial air gap electric motor includes a stator, a rotor, a rotor shaft, two end bells, a housing, a coolant manifold system, and a coolant sump. The rotor includes a plurality of axially directed slots located near its periphery. The coolant manifold system directs a first portion of liquid coolant to flow past some portion of the stator and a second portion of liquid coolant to flow through the rotor slots. Some or all of the liquid coolant is received by the coolant sump from which the coolant may be recirculated.

What is claimed is: 
     
         1 - 11 . (canceled) 
     
     
         12 . A liquid-cooled, radial air gap electric motor comprising:
 a stator having motor windings;   a rotor having an at least partially hollow rotor shaft configured to rotate about a longitudinal axis of rotation;   a housing;   a coolant sump disposed at the bottom of the housing;   a first and a second end-bell, the first end-bell disposed at a first end of the motor housing and the second end-bell disposed at a second end of the motor housing, the first and second end-bells carrying rotor shaft bearings supporting the rotor shaft; and   a coolant manifold coupled to the first end-bell and configured to receive a liquid coolant through a coolant inlet port from a liquid coolant source and to distribute the liquid in at least a first path and a second path, the first path into the at least partially hollow rotor shaft from which the liquid coolant may flow radially outward in operation through one or more shaft radial holes in the at least partially hollow rotor shaft and then longitudinally into a rotor coolant passage formed in the rotor, and then into the sump, the second path radially outward in operation through one or more inlet radial holes in the coolant inlet port and then longitudinally into a peripheral coolant passage formed in a gap disposed between the housing and the stator, and then into the sump;   wherein the stator is electrically insulated from the housing.   
     
     
         13 . A liquid-cooled, radial air gap electric motor comprising:
 a stator having motor windings;   a rotor having an at least partially hollow rotor shaft configured to rotate about a longitudinal axis of rotation;   a housing;   a coolant sump disposed at the bottom of the housing;   a first and a second end-bell, the first end-bell disposed at a first end of the motor housing and the second end-bell disposed at a second end of the motor housing, the first and second end-bells carrying rotor shaft bearings supporting the rotor shaft; and   a coolant manifold coupled to the first end-bell and configured to receive a liquid coolant through a coolant inlet port from a liquid coolant source and to distribute the liquid in at least a first path and a second path, the first path into the at least partially hollow rotor shaft from which the liquid coolant may flow radially outward in operation through one or more shaft radial holes in the at least partially hollow rotor shaft and then longitudinally into a rotor coolant passage formed in the rotor, and then into the sump, the second path radially outward in operation through one or more inlet radial holes in the coolant inlet port and then longitudinally into a peripheral coolant passage formed in a gap disposed between the housing and the stator, and then into the sump;   wherein the rotor is electrically insulated from the housing.   
     
     
         14 . A liquid-cooled, radial air gap electric motor comprising:
 a stator having motor windings;   a rotor having an at least partially hollow rotor shaft configured to rotate about a longitudinal axis of rotation;   a housing;   a coolant sump disposed at the bottom of the housing;   a first and a second end-bell, the first end-bell disposed at a first end of the motor housing and the second end-bell disposed at a second end of the motor housing, the first and second end-bells carrying rotor shaft bearings supporting the rotor shaft; and   a coolant manifold coupled to the first end-bell and configured to receive a liquid coolant through a coolant inlet port from a liquid coolant source and to distribute the liquid in at least a first path and a second path, the first path into the at least partially hollow rotor shaft from which the liquid coolant may flow radially outward in operation through one or more shaft radial holes in the at least partially hollow rotor shaft and then longitudinally into a rotor coolant passage formed in the rotor, and then into the sump, the second path radially outward in operation through one or more inlet radial holes in the coolant inlet port and then longitudinally into a peripheral coolant passage formed in a gap disposed between the housing and the stator, and then into the sump;   wherein the rotor and the stator are electrically insulated from the housing.   
     
     
         15 - 24 . (canceled)