A hydraulic valve assembly (1) with a housing (18) and with a spool (2) which is rotatable in the housing (18). The spool comprising a pressure supply orifice (3) and at least one clutch actuating orifice (4, 5) which is connectable to a clutch actuating cylinder (6, 7). The spool (2) comprises a pressure release orifice (8) which is arranged at the spool (2) so that the pressure release orifice (8) is closed by rotational movement of the spool (2) while the clutch actuating orifice (4, 5) is opened by such rotational movement. The invention further relates to a clutch actuating device with such a hydraulic valve assembly (1) and a corresponding marine propulsion system.

A hydraulic system includes a normally open-type hydraulic clutch which connects or disconnects a power transmission line between an engine and a wheel, an actuator which supplies a hydraulic pressure to the hydraulic clutch, an oil flow path which connects the actuator to the hydraulic clutch, a valve member which is provided on the oil flow path and which enables to switch between an open state where the oil flow path communicates and a closed state where the oil flow path closes, a hydraulic pressure sensor which is provided on the oil flow path, and a bypass flow path which bypasses the valve member. A one-way valve, which permits a supply of a hydraulic pressure from an actuator side to a hydraulic clutch side and which shuts off a supply of a hydraulic pressure from the hydraulic clutch side to the actuator side, is provided on the bypass flow path.

A dual clutch device is provided with a first piston for engaging a first clutch by using hydraulic pressure supplied to a first hydraulic chamber and disengaging the first clutch by using a first spring, a second piston for engaging a second clutch by using hydraulic pressure supplied to a second hydraulic chamber and disengaging the second clutch by using a second spring, first supply lines for supplying hydraulic pressure to the first hydraulic chamber and a second hydraulic canceling chamber, second supply lines for supplying hydraulic pressure to the second hydraulic chamber and a first hydraulic canceling chamber, a first valve for allowing or blocking the hydraulic pressure supply to the first hydraulic chamber and the second hydraulic canceling chamber, and a second valve for allowing or blocking the hydraulic pressure supply to the second hydraulic chamber and the first hydraulic canceling chamber.

A hydraulic control device with a pressure control valve that has a control piston and a modulating piston which can move relative to one another. The control piston and the modulating piston are pushed apart from one another by at least one spring. At one end face of the modulating piston there is arranged a pressure chamber in such a manner that when the pressure chamber is filled, the modulating piston is caused to move in the direction toward the control piston. The pressure chamber can be filled by a first volume flow Q1 of a pressure medium. A venting line, with at least one further throttle, is connected to the pressure chamber. A second volume flow Q2 can be discharged, via the venting line, from the pressure chamber. The hydraulic control device can be utilized in a marine transmission.

Method for determining a kisspoint of a clutch. A method is provided of determining a kisspoint of a clutch in a driveline of a vehicle comprising a. increasing a target clutch pressure of a clutch piston up to a first predetermined test target pressure, b. increasing the target clutch pressure up to an upper target pressure and subsequently keeping the target clutch pressure stable for a predetermined time interval, c. monitoring a parameter indicative for the filling of the clutch piston, e.g. the rotational speed of a pump, during the predetermined time interval, d. repeating steps a., b., and c. for at least one further predetermined test target pressure, and e. determining the kisspoint based on the monitored parameter indicative for the filling of the clutch piston.

This saddle-riding type vehicle includes: a transmission that includes a clutch operated by an operation of a slave cylinder; an oil pressure actuator that includes a master cylinder which generates an oil pressure on an operation oil; an oil pressure valve unit that controls transmission of the oil pressure generated by the master cylinder to the slave cylinder; a master-side connection pipe arrangement that connects the master cylinder to the oil pressure valve unit; and a slave-side connection pipe arrangement that connects the oil pressure valve unit to the slave cylinder, wherein the slave cylinder and the oil pressure valve unit are arranged on one side part in a vehicle width direction of the saddle-riding type vehicle, and the oil pressure actuator is arranged on another side part in the vehicle width direction of the saddle-riding type vehicle.

The present disclosure describes a hydraulic control system comprising a first pressure chamber and a second pressure chamber, each pressure chamber configured to receive a hydraulic fluid, a first movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the first pressure chamber and a second movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the second pressure chamber, a hydraulic command circuit configured to provide the hydraulic fluid and to control the hydraulic pressure of the hydraulic fluid in the first pressure chamber and/or the second pressure chamber, having a switchable valve in fluid communication with the first pressure chamber, wherein the switchable valve is configured to be pilotable depending on the hydraulic pressure of the hydraulic fluid in the second pressure chamber.

Actuation of a hydraulic device that provides a hydraulic supply to a torque-transmitting device is provided. An electrically operated pump is operated in a first operating state. The first operating state; has a primary pump rotational speed that provides a first fluid pressure to the torque-transmitting device via a fluid tract. A switchover process is initiated to operate the electrically operated pump device in a second operating state based on a second fluid pressure and a second fluid target pressure. The second operating state has a secondary pump rotational speed that provides the second fluid pressure to the torque-transmitting device via the fluid tract. During operation of the hydraulic device, the secondary pump rotational speed for the switchover process is determined based on a first power value. The first power value includes electrical pump power of the pump device in a preceding switchover process.

The present disclosure describes a hydraulic control system comprising a first pressure chamber and a second pressure chamber, each pressure chamber configured to receive a hydraulic fluid, a first movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the first pressure chamber and a second movable member configured to assume a position depending on a hydraulic pressure of the hydraulic fluid in the second pressure chamber, a hydraulic command circuit configured to provide the hydraulic fluid and to control the hydraulic pressure of the hydraulic fluid in the first pressure chamber and/or the second pressure chamber, having a switchable valve in fluid communication with the first pressure chamber, wherein the switchable valve is configured to be pilotable depending on the hydraulic pressure of the hydraulic fluid in the second pressure chamber.

A vehicle drive device including an engagement pressure flow channel, a lubrication flow channel, a first pump having a discharge port connected to the engagement pressure flow channel, a second pump, and a flow channel control valve. The flow channel control valve selectively switches flow channels between a first state in which an outflow destination of oil discharged from the second pump is the engagement pressure flow channel and a second state in which the outflow destination is the lubrication flow channel. When a failure in which the flow channel control valve is fixed in the second state has occurred, a control device for a vehicle control device performs fail-safe control in which a rotational speed of at least one of an internal combustion engine and a rotating electrical machine is increased to supply oil to the engagement pressure flow channel by the first pump.