Abstract: A high-pressure pump includes a plunger, a cylinder, a pressuring chamber, a pump body, a main fuel chamber, an auxiliary fuel chamber and a return passage. The cylinder slidably houses the plunger therein. The pump body houses the cylinder and has an end surface on an opposite side of the pump body relative to the pressurizing chamber in an axial direction. The main fuel chamber is in the pump body. The auxiliary fuel chamber has a side defined by one end of the cylinder on an opposite side of the cylinder relative to the pressurizing chamber. The return passage is inside the pump body and is in fluid communication with an external cooling unit. Fuel leaking out from the pressurizing chamber through a clearance between the cylinder and the plunger is collected inside the auxiliary fuel chamber, and the collected fuel flows toward the external cooling unit through the return passage.

Abstract: A high-pressure pump includes a plunger, a cylinder, a pressuring chamber, a pump body, a main fuel chamber, an auxiliary fuel chamber and a return passage. The cylinder slidably houses the plunger therein. Fuel is pressurized inside the pressurizing chamber by sliding movement of the plunger. The pump body houses the cylinder and has an end surface on an opposite side of the pump body relative to the pressurizing chamber in an axial direction. The main fuel chamber is disposed inside the pump body into which fuel is supplied. The auxiliary fuel chamber has a side defined by one end of the cylinder on an opposite side of the cylinder relative to the pressurizing chamber. The return passage is disposed inside the pump body and is in fluid communication with an external cooling unit.