Abstract: A reciprocating piston fluid pump according to the present invention comprising: a pump driving section including a cam operated by an engine and a roller driven by the cam, the roller being provided at a lower end of a piston rod; a piston provided at an upper portion of the piston rod; a pump chamber housing the piston and divided into a piston upper chamber and a piston lower chamber by the piston, the pump chamber including a bearing opening at a central portion of the piston lower chamber, through which the piston rod extends; a rod seal retainer portion provided between the piston rod and the bearing opening of the pump chamber; a spring for urging the piston rod downwardly; oil passage means for communicating the pump upper chamber or the pump lower chamber with the bearing opening, the oil passage means being provided on an oil seal member or the piston rod; oil supply means for supplying lubricating oil to the pump driving section or the bearing opening; and at least one communication hole provided b

Abstract: A centrifugal pump of the vortex-flow type includes a pump housing defining therein an arcuate pump chamber in surrounding relationship with a central sealed chamber, and a disc-like impeller rotatably and axially movably assembled within the pump housing and having opposite end faces each forming a close clearance with a corresponding internal end wall of the pump housing between the sealed and pump chambers, the impeller having on either end face of the rim portion thereof a plurality of circumferentially equally spaced vane grooves which cooperate with the pump chamber to produce a discharge pressure therein and being formed with at least one pressure balancing hole extending axially therethrough in the interior of the sealed chamber.

Abstract: A motor-driven fuel pump including a motor section provided with a driving motor, and a pump section arranged below the motor section and provided with an impeller to be driven by the driving motor. A plurality of pressure compensation hollows are formed on opposite surfaces of a sealing portion of the impeller, and a plurality of communication holes are formed through the sealing portion for communicating the pressure compensation hollows. In another aspect, a plurality of pressure compensation passages are provided to be communicated to a higher pressure side of either a pump chamber defined around outer peripheral vanes of the impeller and a fuel well for receiving a fuel leaked along a sealing portion of the impeller.

Abstract: A slide type vacuum pump has a cylinder bore with a cylindrical piston reciprocatingly slidably fitted therein and defining a vacuum pumping chamber. A seal element is housed in an annular groove around the piston defined by a radially extending annular surface and an axially extending cylindrical surface. The seal element includes an inwardly radially extending annular portion axially abutted against the annular groove defining surface and an axially extending cylindrical portion slidingly sealing against the cylinder bore. A first spring member has an inwardly radially extending annular portion axially abuttingly holding the annular seal element portion against the annular groove defining surface, and several axially extending resilient finger portions each angled outwards somewhat and springingly pressing the cylindrical seal element portion radially outwards against the cylinder bore to effect sealing therebetween.

Abstract: A canister for a volatile fuel controlling device having a volatile fuel inlet, a mixture outlet and an air introduction port, in which a baffle is provided within a volatile fuel absorbent layer for restricting the flow of the volatile fuel and air between the volatile fuel inlet and mixture outlet side and the air introduction port side, so that the absorbing efficiency of the volatile fuel by the absorbent and the eliminating efficiency thereof from the absorbent can be increased, thereby contributing to the minimization of canister size and the prevention of unburned gas emission.

Abstract: A canister for a volatile fuel controlling device having a volatile fuel inlet, a mixture outlet and an air introduction port, in which a baffle is provided within a volatile fuel absorbent layer for restricting the flow of the volatile fuel and air between the volatile fuel inlet and mixture outlet side and the air introduction port side, so that the absorbing efficiency of the volatile fuel by the absorbent and the eliminating efficiency thereof from the absorbent can be increased, thereby contributing to the minimization of canister size and the prevention of unburned gas emission.