Electric pump system and method with hollow shaft and temperature sensor

A method of pumping a fluid in an electric pump system having a mechanical pump, a motor including a stator and a rotor comprising a hollow shaft, the motor having a first side and a pump side, and a motor housing defining an internal motor cavity, the method comprising:

• controlling the mechanical pump via an electric control unit connected to the first side of the motor;
• pumping fluid along a first fluid flow path through a first fluid passageway from a first pump inlet of the mechanical pump to a pump outlet of the mechanical pump;
• pumping fluid along a second fluid flow path through a second fluid passageway from the internal motor cavity to the pump outlet via a second pump inlet of the mechanical pump, wherein the fluid along the second fluid flow path flows through the hollow shaft of the rotor from a shaft inlet to a shaft outlet into the internal motor cavity, past the stator and the rotor and through the motor housing into a third fluid passageway that extends to the pump outlet;
• pumping fluid into a bypass inlet which is in fluid communication with a portion of the second fluid flow path that flows past the stator and the rotor and through the motor housing into the third fluid passageway, the bypass inlet being proximate to the first side of the motor;
• detecting, via a temperature sensor located adjacent to the shaft outlet, a temperature of the fluid exiting the hollow shaft;
• and
• determining a required amount of heat that needs to be rejected from the fluid via evaluation of a plurality of corrective actions responsive to the detected temperature of the fluid exiting the hollow shaft;
• wherein the plurality of corrective actions comprises rejecting heat by the electric pump system or a change to a motor parameter of a motor associated with a vehicle.

An apparatus for pumping a fluid comprising:

• a motor including:
• a stator;
• a rotor comprising a hollow shaft;
• and
• a housing around the stator and rotor and defining an internal motor cavity;
• an electronic control unit connected to a first side of the motor, the electronic control unit comprising a microcontroller and a thermistor configured to measure a temperature of the fluid;
• wherein the electronic control unit is configured to determine a change to an operation of a vehicle associated with said apparatus;
• a mechanical pump comprising a first pump inlet, a second pump inlet, and a pump outlet, the mechanical pump connected to the motor through the first pump inlet and connected to the motor through a second pump inlet;
• a first fluid passageway from the first pump inlet to the pump outlet;
• a second fluid passageway extending through the internal motor cavity to the pump outlet via the second pump inlet, wherein a fluid flow path extends through the second fluid passageway into the hollow shaft of the rotor from a shaft inlet to a shaft outlet into the internal motor cavity, past the stator and the rotor into a third fluid passageway that extends to the pump outlet, and wherein the thermistor is configured to measure the temperature of the fluid exiting the shaft outlet of the hollow shaft;
• and
• a bypass inlet proximate to the first side of the motor, the bypass inlet being in fluid communication with a portion of the fluid flow path that flows past the stator and the rotor and through the motor housing into the third fluid passageway.