A method and an apparatus for learning linearity error of a hydraulic pressure sensor for a hydraulic clutch are disclosed. An apparatus for learning linearity error of a hydraulic pressure sensor for a hydraulic clutch may include: a gear stage sensor detecting a gear stage that is currently engaged; a controller executed by a predetermined program to learn the linearity error of the hydraulic pressure sensor based on signals of the gear stage sensor and the hydraulic pressure sensor; and a solenoid valve applying hydraulic pressure for learning the linearity error of the hydraulic pressure sensor to the hydraulic clutch based on a learning command of the controller.

Systems and methods of controlling a clutch in a hybrid vehicle with a manual transmission, are provided. With the goal of enabling autonomous/assisted clutch control in a hybrid vehicle, while preserving the familiar mechanical feeling at the clutch pedal that driving enthusiasts prefer, embodiments of the disclosed technology use a shuttle valve to blend control of clutch engagement between a driver and an ECU. In these embodiments, a clutch pedal in the vehicle may be mechanically connected to a piston in a first hydraulic cylinder (just like in a traditional mechanical/hydraulic clutch actuation system), and an ECU may actuate a second hydraulic cylinder. Accordingly, a shuttle valve may be used to route the fluid coming from the cylinder with the greater pressure (i.e. the driver actuated cylinder or the ECU actuated cylinder), to a third hydraulic cylinder which adjusts engagement of a clutch by a mechanical linkage.

An actuation pressure to actuate one or more hydraulic actuators may be determined based on a load on the one or more hydraulic actuators of a robotic device. Based on the determined actuation pressure, a pressure rail from among a set of pressure rails at respective pressures may be selected. One or more valves may connect the selected pressure rail to a metering valve. The hydraulic drive system may operate in a discrete mode in which the metering valve opens such that hydraulic fluid flows from the selected pressure rail through the metering valve to the one or more hydraulic actuators at approximately the supply pressure. Responsive to a control state of the robotic device, the hydraulic drive system may operate in a continuous mode in which the metering valve throttles the hydraulic fluid such that the supply pressure is reduced to the determined actuation pressure.

A hybrid driving device that includes a first input that is linked to an internal combustion engine; a rotary electric machine; a transmission that changes a speed of rotation of a second input, and transmits the rotation to an output; a rotor support which rotates integrally with a rotor of the rotary electric machine; a first engagement device; a second engagement device; and a case.

A pneumatic and hydraulic elevating seat tube assembly of a bicycle includes an outer tube and a movable inner tube in the outer tube. An elevating adjustment unit in the movable inner tube has a fixed inner tube in the movable inner tube, a fixed piston in the fixed inner tube, a floating piston in the fixed inner tube, and an elastic isolator in the floating piston which is between a bottom end of the movable inner tube and the fixed piston so that a gas chamber is formed between the floating piston and the movable inner tube and a lower oil chamber is formed between the floating piston and the fixed piston. The elastic isolator has first and second annular grooves facing toward the lower oil chamber and the gas chamber respectively. The elastic isolator under pressure is extended radially, thereby effective in isolating oil from gas positively.

An actuation pressure to actuate one or more hydraulic actuators may be determined based on a load on the one or more hydraulic actuators of a robotic device. Based on the determined actuation pressure, a pressure rail from among a set of pressure rails at respective pressures may be selected. One or more valves may connect the selected pressure rail to a metering valve. The hydraulic drive system may operate in a discrete mode in which the metering valve opens such that hydraulic fluid flows from the selected pressure rail through the metering valve to the one or more hydraulic actuators at approximately the supply pressure. Responsive to a control state of the robotic device, the hydraulic drive system may operate in a continuous mode in which the metering valve throttles the hydraulic fluid such that the supply pressure is reduced to the determined actuation pressure.

A drive force transfer device that includes a friction clutch with improved response at the time when the friction clutch is pressed by a hydraulic pressure is provided. A drive force transfer device has: a clutch drum; an inner shaft; a friction clutch that has a plurality of outer clutch plates that are rotatable together with the clutch drum and a plurality of inner clutch plates that are rotatable together with the inner shaft; a piston that receives a hydraulic pressure supplied to a cylinder to press the friction clutch; and a hydraulic circuit that supplies the cylinder with working oil. The hydraulic circuit has a first pump portion that supplies the cylinder with the working oil, and a second pump portion that supplies the cylinder with the working oil at a pressure that is higher than that of the working oil supplied by the first pump portion.

A four-wheel drive vehicle includes a friction clutch that transmits a driving force to rear wheels, a hydraulic circuit including a control valve that reduces a pressure of hydraulic oil discharged from a hydraulic pump down to a control pressure corresponding to a control current, and the cylinder and a piston that receives the oil from hydraulic circuit the to press the friction clutch. In the hydraulic circuit, a ratio of an change amount in a feeding pressure to the cylinder to an change amount in the control current, when the feeding pressure to the cylinder is lower than a predetermined value, is lower than when the feeding pressure applied to the cylinder is equal to or higher than the predetermined value. The control apparatus controls a pressure of the hydraulic oil fed to the cylinder lower than the predetermined value when switching the driving state.

A hybrid system includes an engine, a speed change device, a differential device, a rotary machine, a first engagement device, a case, and a cover wall. The first engagement device is configured to shift the speed change device, and be actuated by hydraulic pressure. The first engagement device includes a first oil chamber. The rotary machine is arranged between the first engagement device and the engine. The case houses the rotary machine, the speed change device, the differential device, and the first engagement device, and is connected to the engine and has an opening on the engine side. The cover wall covers the opening, and operating oil is supplied to the first oil chamber via the cover wall.

A method for stabilizing an engine clutch control includes transmitting an engine clutch operation start command from a controller to an engine clutch system, the engine clutch system including an engine clutch, detecting a hydraulic pressure generated during the operation of the engine clutch system, carrying out an oil leakage judgment mode using the controller so as to judge whether the hydraulic pressure is a normal hydraulic pressure where the operation of the engine clutch is available or if the hydraulic pressure an abnormal hydraulic pressure where the operation of the engine clutch is unavailable, and changing an operation mode to an emergency operation mode wherein the operation of the engine clutch is stopped in case of abnormal hydraulic pressure, and carrying out an operation mode change by operating the engine clutch in a case of normal hydraulic pressure, based on a control by the controller.