Electric motor with water jacket and oil-cooled stator and method for operation of the electric motor

A method for an electric motor-cooling system comprising:

• flowing a coolant which includes water through a water jacket in a housing that is directly coupled to a stator;
• flowing oil through an oil inlet that extends through the water jacket and an inner wall and an outer wall of the housing;
• flowing the oil from the oil inlet to one or more axially extending oil ducts that traverse at least a portion of a plurality of stator laminations;
• and
• thermally conducting heat from the oil to the water jacket through the inner wall in the housing;
• wherein the oil inlet extends radially outward from the outer wall;
• wherein the oil inlet is coupled to the outer wall via multiple fasteners;
• wherein the inner wall is positioned radially inward from the water jacket and the outer wall is positioned radially outward from the water jacket;
• wherein a working fluid in the water jacket includes water and the working fluid in the oil inlet and the one or more axially extending oil ducts is oil;
• wherein the water jacket is fluidly separated from the oil inlet and the one or more axially extending oil ducts;
• wherein a plurality of seals are provided between the oil inlet and the housing;
• and
• wherein the oil inlet extends through the outer wall, the inner wall, and the water jacket.

An electric motor, comprising:

• a housing including a water jacket;
• a stator including a plurality of stator laminations with a peripheral surface that forms an interface with the housing;
• an oil inlet mounted to an outer wall of the housing via multiple fasteners;
• wherein the oil inlet extends through the outer wall, an inner wall of the housing, and the water jacket;
• and
• a plurality of seals provided between the oil inlet and the housing;
• wherein the plurality of stator laminations include a radial opening designed to:
• receive oil from the oil inlet;
• and
• direct the oil to a plurality of oil ducts axially extending through at least a portion of the plurality of stator laminations;
• wherein the plurality of oil ducts have a plurality of baffles;
• an oil sump coupled to the housing and configured to receive the oil from the plurality of oil ducts;
• and
• an oil pump including an inlet in fluidic communication with the oil sump;
• wherein an oil line extends directly from an outlet of the oil pump to the oil inlet;
• wherein the inner wall is positioned radially inward from the water jacket and the outer wall is positioned radially outward from the water jacket;
• wherein a working fluid in the water jacket includes water and the working fluid in the oil inlet and the plurality of oil ducts is oil;
• and
• wherein the water jacket is fluidly separated from the oil inlet and the plurality of oil ducts.