US Patent 11448117 Auxiliary coolant pump with bypass

An auxiliary coolant pump for circulating a coolant in a vehicle thermal system having a main coolant pump includes a housing, an impeller, a motor selectively driving the impeller, a coolant inlet configured to receive the coolant, a coolant outlet fluidly coupled to the coolant inlet, and a bypass passage fluidly coupled between the coolant inlet and the coolant outlet. When the main coolant pump is on, the auxiliary coolant pump is selectively turned off such that coolant flows through the bypass passage to reduce or eliminate restriction of the coolant flow rate in the thermal system. When the main coolant pump is off, the auxiliary coolant pump is selectively turned on such that coolant continues to flow through at least a portion of the thermal system.