Dual volute electric pump, cooling system and pump assembly method

A cooling system for an electric drive machine comprising:

• a first cooling fluid circuit including a plurality of cooling circuit segments;
• a second cooling fluid circuit fluidly separate from the first cooling fluid circuit and including another plurality of cooling circuit segments;
• and
• an electrically powered pump including a plump housing having a first volute that includes a cooling circuit segment of the first cooling fluid circuit and a second volute that includes a cooling circuit segment of the second cooling fluid circuit, the pump housing further defining a first fluid inlet to the pump housing and a first fluid outlet from the pump housing each fluidly connecting with the first volute, and a second fluid inlet to the pump housing and a second fluid outlet from the pump housing each fluidly connecting with the second volute:
• the electrically powered pump further including a drive assembly that includes an electric motor and a pump shaft rotatable via the electric motor, a first impeller mounted to the pump shaft and having a first impeller configuration, and a second impeller mounted to the pump shaft and having a second, different impeller configuration.

A method of assembling an electrically powered pump for a cooling system in a machine comprising:

• assembling a pump shaft having a longitudinal shaft axis with a bearing housing that includes a bearing bore therein and a pump shaft bearing positioned within the bearing bore;
• locating a first impeller having a first impeller configuration at a first axial position on the pump shaft at least in part via contacting a first axial side of the bearing housing with a locating device during pressing the first impeller onto the pump shaft;
• coupling a drive assembly with the pump shaft, including connecting a first axial side of an electrical motor housing of the drive assembly with a second axial side of the bearing housing;
• and
• locating a second impeller having a second, different impeller configuration at a second axial position on the pump shaft at least in part via contacting a second axial side of the electrical motor housing with a locating device during pressing the second impeller onto the pump shaft.

An electrically powered pump for a cooling system in a machine comprising:

• a fluid pumping mechanism including a drive assembly having an electric motor and a pump shaft rotatably coupled with the electric motor and including a first axial end and a second axial end, the fluid pumping mechanism further including a first impeller mounted to the pump shaft adjacent the first axial end and a second impeller mounted to the pump shaft adjacent the second axial end;
• and
• a pump housing including an outer surface, a first volute positioned about the first impeller and including a first cooling circuit segment and a second volute positioned about the second impeller and including a second cooling circuit segment, the pump housing further including a two-piece motor housing which contains the electric motor and is positioned between the first volute and the second volute and arranged coaxially about the pump shaft, the two-piece motor housing having a first motor housing piece and a second motor housing piece mated with the first motor housing piece and each including a portion of the outer surface of the pump housing,
• wherein the first motor housing piece includes a first axially inward segment defining a first bearing bore having a first pump shaft journal bearing positioned therein and a first axially outward segment projecting into the first volute and defining a first water seal bore having a first water seal positioned therein;
• and
• wherein the second motor housing piece includes a second axially inward segment defining a second bearing bore having a second pump shaft journal bearing positioned therein and a second axially outward segment projecting into the second volute and defining a second water seal bore having a second water seal positioned therein.