Rotary pump with pressure switch

Abstract

In a rotary pump with a pressure switch, a pressure switch mounting space constituted by a small- and large-diameter holes is formed to be parallel to a rotating shaft in an end face portion of a front body to which a rear body is not joined. A pump outlet side fluid pressure is introduced to an inner end of the small-diameter hole. The large-diameter hole is connected to a pump inlet side. A plunger is slidably arranged in the small-diameter hole. The plunger is normally biased toward the inner end of the small-diameter hole and is kept movable toward the large-diameter hole depending on a magnitude of the fluid pressure of the pump outlet side. A pressure detector is operated when the fluid pressure of the pump outlet side exceeds a predetermined value. The pressure detector includes a terminal arranged in the large-diameter hole and having an inner end opposing an end portion, of the plunger, located in the large diameter hole, and an outer end connected to a lead from a switch circuit, and a holding member for holding the terminal at an open end portion of the pressure switch mounting space while keeping the terminal insulated. Removal of a thermal holding member in the mounting spacer is prevented by the gasket plate inserted between the two bodies.