Showa Corporation

Takeshi Ueki

Hayato Tsutsui

Shingo Ishige

Shinya Horie

Nobuaki Tanaka

Kazuhiko Sadakata

Morihito Ichizuki

Kenzo Oba

Yoshinobu Yamada

A first case accommodating a first check valve of a switching valve switching a flow of hydraulic fluid to one of a first chamber and a second chamber of a cylinder device, an inside of which is segmented into the first chamber and the second chamber by a piston, and a second case which is stacked on the first case and in which a first actuation valve of the switching valve is accommodated to be displaced in a direction of stacking the first case are provided. A first valve chamber, accommodating the first actuation valve, of the second case has a pressure receiving surface on which pressure of hydraulic fluid that acts on the first valve chamber acts toward the first case.

Pump device and hydraulic actuator

Provided is a pump device and a hydraulic actuator that can reduce the number of steps of performance measurement. The pump device includes: a switching valve for switching a flow of oil to a first chamber or a second chamber of a cylinder device, the inside of which is segmented into the first chamber and the second chamber by a piston; an up blow valve (first chamber-side relief valve) that relieves pressure of a first chamber-side flow path connected to the first chamber; and a down blow valve (second chamber-side relief valve) that relieves pressure of a second chamber-side flow path connected to the second chamber.

A trim and tilt apparatus for a marine vessel propulsion machine includes: a cylinder having a cylinder chamber; a piston rod that is telescopically inserted into the cylinder chamber; and a hydraulic oil supply and discharge device that supplies and discharges hydraulic oil to and from the cylinder chamber, the trim and tilt apparatus allowing the marine vessel propulsion machine to perform a trim operation and a tilt operation, and the hydraulic oil supply and discharge device includes: a plurality of discharge units for simultaneously discharging the hydraulic oil; and a switching unit for switching between a case where the cylinder chamber is supplied with the hydraulic oil discharged by a part of the plurality of discharge units, and a case where the cylinder chamber is not supplied with the hydraulic oil discharged by the part of the plurality of discharge units.

Trim and tilt apparatus for marine vessel propulsion machine

In a variable displacement pump, an outer peripheral surface approximately in an opposite side to a portion supported to an oscillation supporting point in a cam ring with respect to a pump shaft is formed as a convex surface portion holding a seal member brought into slidable contact with an inner peripheral surface of an outer case, and an inner peripheral surface of the outer case with which the seal member held to the convex surface portion of the cam ring is brought into slidable contact is formed as a circular arc surface around the oscillation supporting point.

Variable displacement pump

In a variable displacement pump, a first groove always connected to a second hydraulic chamber is provided in a slide surface of a cam ring facing to an end surface of a side plate, and a second groove always connected to a suction port is provided in the end surface of the side plate, whereby when the cam ring is moved to a moving end side in which a volumetric capacity of a pump chamber is reduced, the first groove and the second groove are connected, and the second hydraulic chamber can be connected to the suction port by the grooves.

In a variable displacement pump provided with a high pressure chamber formed at a position facing to a discharge region of a pump chamber between a back surface of a side plate and a pump casing and introducing a pump discharge side pressure oil, a low pressure chamber formed at a position facing to a suction region of the pump chamber between the back surface of the side plate and the pump casing, and communicating with a suction region of the pump chamber, and an annular seal member interposed between the back surface of the side plate and the pump casing, and surrounding the low pressure chamber together with a lubricating oil path around the pump shaft, the annular seal member is provided with a bridge portion connecting both ends of a U-shape of an approximately U-shaped portion of the annular seal member along the lubricating oil path around the pump shaft.

A relief valve is provided with an elastic body seal sealed into an annular gap between a ball receiver and a valve hole, and is slidably in contact with an inner periphery of the valve hole such that the elastic body seal is not compressed in an axial direction of the ball receiver.

Growing community of inventors

Haga-gun, Japan

Takeshi Ueki