Kabushiki Kaisha Fujikoshi

Takashi Nishimoto

Hiroyoshi Takamori

Seiichi Suzuki

Mineyuki Naruse

Tohru Matsuoka

Fumio Honda

A solenoid valve comprising a valve body, and a poppet vertically slidable within the valve body and moved to and from a valve seat so as to open and close an oil passage. The poppet is in the form of a cylindrical tube and is slidably fit around and supported by a guide rod in an oil-tight manner. The guide rod has a valve seat at its bottom and an oil passage for communication with the interior of the poppet. Features of the present invention are as follows. The guide rod has a surface on which the inner peripheral surface of the poppet is slidable. The outer diameter of such a surface of the guide rod is slightly smaller than that of the valve seat. In this way, the solenoid valve acts as an on-off valve and a relief valve. The valve of the type as thus far explained further includes a passage for reducing the flow velocity of an oil as pressurized between the poppet and the guide rod. A surface of the poppet is shaped to maintain an oil film between the poppet and the valve seat. An armature is integrally formed with the head of the poppet and is shaped in such a manner that the solenoid valve is opened in proportion to input current. The present invention is, thus, applicable to a proportional control valve.

Solenoid valve

A shaft sealing means for use in a hydraulic pump/motor having a rotary shaft rotating within its body, an oil seal fitted in the gap between the rotary shaft and the body for sealing therebetween and between the high and low pressure sides, and a spacer fixed in the gap. The shaft sealing means comprises anti-protrusion means fitted relatively tightly in the gap with its high pressure side surface in close contact with the low pressure side surface of the oil seal for preventing protrusion of the oil seal toward the low pressure side, and anti-friction means inserted in the gap between the anti-protrusion means and the spacer for providing a sliding motion between the anti-protrusion means and the spacer thereby reducing the generation of frictional forces therebetween. This construction eliminates the possibility of damaging the oil seal thereby preventing oil leakage and also resulting in an improved shaft sealing means for use in a high pressure and/or high speed hydraulic pump/motor having a long service life.

Growing community of inventors

Toyama, Japan

Takashi Nishimoto