Electric motor cooling jacket assembly and method of manufacture

A cooling jacket assembly for cooling a stator of an electric machine, said assembly comprising

• an annular cooling jacket body comprising coaxial inner and outer cylindric extruded shells defining an annular gap therebetween,
• said inner shell having an outer surface and a cylindric inner surface defining a cylindric cavity for receiving said stator so that the stator is in heat transfer contact with said inner surface,
• heat transfer fins in the annular space between the inner and outer shells defining flow channels for flow of coolant therethrough,
• a first annular end cap connected to one end of the cooling jacket body and defining an annular conduit around the body in fluid communication with said flow channels,
• a second annular end cap connected to an opposite end of the cooling jacket body and defining an annular conduit around the body in fluid communication with said flow channels,
• an inlet on one of the end caps for flow of coolant into a respective conduit,
• an outlet on one of the end caps for flow of coolant out of a respective conduit,
• barriers in the conduits for directing fluid from the inlet through the flow channels to the outlet along at least one serpentine path, said at least one path comprising at least first, second and third parallel sections extending axially of the cooling jacket body and connected by said conduits, each section of said at least one serpentine path comprising a group of flow channels defined by a plurality of adjacent fins,
• the arrangement being such that coolant flows in a first axial direction through the flow channels of the first section, then in a second axial direction substantially opposite the first through the flow channels of the second section, and then in said first axial direction through the flow channels of the third section.

A cooling jacket assembly for cooling a stator of an electric machine, said assembly comprising

• an annular cooling jacket body comprising coaxial inner and outer cylindric extruded shells defining an annular gap therebetween,
• said inner shell having an outer surface and a cylindric inner surface defining a cylindric cavity for receiving said stator so that the stator is in heat transfer contact with said inner surface,
• heat transfer fins in the annular space between the inner and outer shells defining flow channels for flow of coolant therethrough,
• a first annular end cap connected to one end of the cooling jacket body,
• a second annular end cap connected to an opposite end of the cooling jacket body,
• an inlet on one of the end caps for flow of coolant into the flow channels,
• an outlet on one of the end caps for flow of coolant from the flow channels,
• means for directing coolant from the inlet through the flow channels to the outlet along at least one serpentine path, and
• cooperating registration elements on the cooling jacket body and the first and second end caps for properly orienting the end caps relative to the body during assembly of the body and the end caps, said cooperating registration elements comprising integral axial projections formed as integral parts of either the cooling jacket body or the end caps and recesses in the other of the cooling jacket body and the end caps for receiving the integral axial projections.

A cooling jacket assembly for cooling a stator of an electric machine, said assembly comprising

• an annular cooling jacket body comprising coaxial inner and outer cylindric extruded shells defining an annular gap therebetween,
• said inner shell having an outer surface and a cylindric inner surface defining a cylindric cavity for receiving said stator so that the stator is in heat transfer contact with said inner surface,
• heat transfer fins in the annular space between the inner and outer shells defining flow channels for flow of coolant therethrough,
• a first annular end cap connected to one end of the cooling jacket body and defining an annular conduit around the body in fluid communication with said flow channels,
• a second annular end cap connected to an opposite end of the cooling jacket body and defining an annular conduit around the body in fluid communication with said flow channels,
• an inlet on one of the end caps for flow of coolant into a respective conduit,
• an outlet on one of the end caps for flow of coolant out of a respective conduit,
• barriers in the conduits for directing fluid from the inlet through the flow channels to the outlet along at least one serpentine path, said at least one serpentine path comprising a plurality of parallel sections extending axially of the cooling jacket body and connected by said conduits, and
• at least one ramp in said conduits extending across the inlet end of at least one of said parallel sections for effecting a more uniform distribution of fluid through the flow channels of said at least one section.