The present invention relates to a vehicle (1) having a torque generating machine (4); and one or more driven wheel (W.sub.D). A driveline (6) is provided for transmitting torque from the torque generating machine (4) to said one or more driven wheel. The driveline (6) includes a torque transmitting means (8). A first decoupling mechanism (11) is operable to decouple the torque transmitting means (8) from the torque generating machine (4). The first decoupling mechanism (11) is closed to couple the torque transmitting means (8) to the torque generating machine (4) and is opened to decouple the torque transmitting means (8) from the torque generating machine (4). A second decoupling mechanism (12) is operable to decouple the torque transmitting means (8) from the one or more driven wheel. The second decoupling mechanism (12) is closed to couple the torque transmitting means (8) to the one or more driven wheel and is opened to decouple the torque transmitting means (8) from the one or more driven wheel. A controller (2) is provided having at least one electronic processor for controlling operation of the first and second decoupling mechanisms (11, 12). The at least one electronic processor (P) is configured to close the first decoupling mechanism (11), to determine a target operating speed of the torque generating machine (4), to control the operating speed of the torque generating machine (4) in dependence on the determined target operating speed and to close the second decoupling mechanism (12) when the operating speed of the torque generating machine (4) at least substantially matches the determined target operating speed. The present invention also relates to a corresponding method of controlling first and second decoupling mechanisms (11, 12) to control the transmittal of torque from a torque generating machine (4) to one or more driven wheel of a vehicle (1).

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 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.

The present invention relates, inter alia, to a method for regulating the engagement position of a position-controlled clutch unit for a drive train of a motor vehicle. The clutch unit has at least one wet-running friction clutch for the controllable transmission of a torque from an input element to an output element and an actuator for setting the engagement position for the purposes of mutual compression of the input and output elements. The method compensates a time-dependent setting behavior of the friction clutch on the basis of the uptake of lubrication oil of the friction clutch, which varies over time, in that the engagement position of the clutch unit is regulated by means of the actuator as a function of the time-dependent setting behavior.

A method determines the travel of a clutch in a hydraulic clutch-actuation system. A hydraulic signal which extends between a transmitting end and a receiving end is acted upon by an acoustic signal for the generation of a wave packet. The acoustic signal on the transmitting end of the clutch-actuation system is fed into the hydraulic fluid, a wave packet generated by the acoustic signal on the receiving end is reflected back to the transmitting end, a running time of the transmitted and reflected wave packet on the transmitting end is evaluated to determine the coupling travel.

A method for calibrating a characteristic diagram for a drive-train of a working machine, which contains a brake pedal characteristic of a brake system and a clutch characteristic of a drive clutch, in which an opening point at which the drive clutch is disengaged when a brake pedal of the brake system is actuated as a function of a pedal path, and/or a closing point at which the drive clutch is engaged when the brake pedal is released as a function of the pedal path, is calibrated. When the brake pedal is actuated and/or released an actual rotational speed profile of the drive-train is determined, the actual rotational speed profile determined is compared with a stored corresponding target rotational speed profile, and the opening point and/or closing point of the drive clutch is adapted to minimize deviation of the actual rotational speed profile from the target rotational speed profile.

A method for calibrating a characteristic diagram for a drive-train of a working machine, which contains a brake pedal characteristic of a brake system and a clutch characteristic of a drive clutch, in which an opening point at which the drive clutch is disengaged when a brake pedal of the brake system is actuated as a function of a pedal path, and/or a closing point at which the drive clutch is engaged when the brake pedal is released as a function of the pedal path, is calibrated. When the brake pedal is actuated and/or released an actual rotational speed profile of the drive-train is determined, the actual rotational speed profile determined is compared with a stored corresponding target rotational speed profile, and the opening point and/or closing point of the drive clutch is adapted to minimize deviation of the actual rotational speed profile from the target rotational speed profile.

Coupling mechanisms for torque transmitting shafts are provided with sliding and fixed plates operably connectable to respective torque transmitting shafts, and a leaf spring having a preloaded spring force exerted on the sliding plate when the sliding and fixed plates are operably connected to one another. A hub is attached to the leaf spring and coaxially received within the sliding plate to allow the sliding plate to be capable of reciprocal axial movements relative to the hub between engaged and disengaged positions wherein the sliding and fixed plates are engaged and disengaged with one another so as to allow and prevent torque being transmitted from one to another of the shafts, respectively. An inner piston is coaxially received within the hub and moveable between a first position wherein the hub retains the sliding plate in the engaged position thereof, and a second position wherein the hub releases the sliding plate to allow movement of the sliding plate under bias force from the leaf spring into the disengaged position thereof.

A controller causes a clutch to transition from a half-engaged state to an engaged state when a difference in rotational velocity between input and output sides of the clutch falls within a predetermined range in the half-engaged state of the clutch. The controller executes a moving start control to increase an output rotational velocity of a prime mover and cause the clutch to transition to the engaged state when a predetermined first condition is satisfied in the half-engaged state of the clutch.

A controller causes a clutch to transition from a half-engaged state to an engaged state when a difference in rotational velocity between input and output sides of the clutch falls within a predetermined range in the half-engaged state of the clutch. The controller executes a moving start control to increase an output rotational velocity of a prime mover and cause the clutch to transition to the engaged state when a predetermined first condition is satisfied in the half-engaged state of the clutch.