Abstract: When the pressure in a main fluid supply channel is lower than a no-load operation start pressure, the spool moves against the biasing force of a biasing member, and the area of opening of a auxiliary fluid supply channel is reduced with regards to opening of the internal flow channel. When the pressure in the main fluid supply channel rises and reaches a no-load operation start pressure, the area of opening in the auxiliary fluid supply channel with regards to opening of the internal flow channel becomes smaller and while connected to the main fluid supply channel, the auxiliary fluid supply channel is connected to the return flow channel. When the pressure in the main fluid supply channel rises above the no-load operating start pressure and reaches a no-load operation pressure, the auxiliary fluid supply channel is cut off from the main fluid supply channel.

Abstract: A pump pulley is supported on a pump body via a bearing interposed between the outer peripheral surface of the pump body and the pump pulley so that the pump pulley can freely rotate relative to the pump body. A pump shaft extends along the rotation axis of the pump pulley into a pump chamber formed by a pump base and the pump body, and one end of the pump shaft is fitted to the pump pulley and the other end is fitted to an impeller located within the pump chamber. A body side seal member and a shaft side seal member that form a mechanical seal to maintain the leak tightness of the pump chamber are in opposite to and contact each other in the direction of extension of the pump shaft to form a seal surface, and the plane that includes the load support center of the bearing and the plane that includes the seal surface of the mechanical seal are substantially coincidental.

Abstract: When the pressure in the main oil supply channel is lower than the no-load operation start pressure, the pressurized oil within the secondary oil supply channel passes through the internal flow channel of the spool and flows into the main oil supply channel. At this time oil output from both the main and secondary oil pumps is merged and supplied to the oil supply destination. When the pressure within the main oil supply channel rises and reaches the no-load operation start pressure, the spool moves in opposite direction to the direction of the force of the spring, the pressurized oil within the secondary oil supply channel is drained, the poppet contacts the spool and blocks the internal flow channel of the spool. At this time, the secondary oil pump enters the no-load operation state, and oil output from the main oil pump only is transmitted to the oil supply destination.

Abstract: When the pressure in a main fluid supply channel is lower than a no-load operation start pressure, and auxiliary fluid supply channel is communicated with the main fluid supply channel through the internal flow channel of a spool, and as the pressure rises within the main fluid supply channel, the spool moves against the biasing force of a biasing member, and the area of opening of the auxiliary fluid supply channel is reduced with regards to opening of the internal flow channel. When the pressure in the main fluid supply channel rises and reaches a no-load operation start pressure, the area of opening in the auxiliary fluid supply channel with regards to opening of the internal flow channel becomes smaller and while connected to the main fluid supply channel, the auxiliary fluid supply channel is connected to the return flow channel.

Abstract: A casing with housing space for retaining a first gear and a second gear in a condition where the tooth tips and both side surfaces slide, comprises a main casing which retains the first gear in a manner which allows rotation but restricts movement in the axial direction, and a gear holder which can move in the rotating shaft direction in the main casing and which rotatably retains the second gear. The main casing contains a biasing member which applies a biasing force to bias the gear holder to one side in the rotating shaft direction, and a piston which is acted on by hydraulic pressure and presses the gear holder on the other end side in the rotating shaft direction to counteract the biasing force. The gear holder is acted on by the hydraulic force from the piston to counteract the bias from the biasing member and moves in the rotating shaft direction according to the hydraulic force so that the engagement width between the first gear and the second gear which is retained by the gear holder is changed.