Abstract: A vehicle air conditioning system includes a refrigerant circuit, a heat medium circuit, a vehicle-interior heat exchanger, a vehicle-exterior heat exchanger including a first heat exchanger and a second heat exchanger disposed in series with respect to a flow of air generated by an air blower, a switching unit, a detection unit for detecting a degree of frost formation, and a control device. The operation mode includes a defrosting mode in which the heat medium in the high-temperature medium circuit is supplied to a defrosting target to be selected as either the first or second heat exchanger by the operation of the switching unit. The control device selects, as the defrosting target, the first heat exchanger in preference to the second heat exchanger when determined that both the first and the second heat exchangers need to be defrosted.

Abstract: A pump comprises a housing having a shaft bore and a pump chamber, a bearing provided for an inner periphery of the shaft bore, a shaft rotatively supported by the shaft bore through the bearing, and a transporting member connected to one end portion of the shaft for transporting fluid by imparting mechanical energy to the fluid sucked in said pump chamber.