A method for determining a service life of a friction clutch of a vehicle with a clutch actuation system includes setting a maximum torque at the friction clutch of the clutch actuation system. The method also includes incrementing a service life counter when an unintended slip at the friction clutch occurs, determining that wear has occurred on the friction clutch in response to reaching a specific counter value of the service life counter, and multiplying a weighted sensitivity factor by a first absolute vale which increments the counter in response to an unintended slip occurring.

The friction engagement device connects the input shaft and the output shaft to transmit a driving force from a driving source from the input shaft to the output shaft. The friction engagement device includes a housing, a friction engagement portion, a piston, an oil pump, and a motor. The housing is disposed between the input shaft and the output shaft. The friction engagement portion is disposed in the housing and composed of a plurality of friction components. The piston is disposed at one side of the friction engagement portion for pressing the friction engagement portion. The oil pump is used to operate the piston. The motor is used to drive the oil pump. In the friction engagement device, abnormal wear of the friction components of the friction engagement portion is detected by monitoring a value of an operation parameter of the friction engagement device.

A power transmission device with a clutch plate wear sensor system includes a power transmission shaft configured to transmit torque and a clutch configured to selectively deliver power into or out of the power transmission shaft. The clutch includes a clutch stack and clutch piston that moves to selectively actuate the clutch stack between an engaged state to deliver power through the clutch and a disengaged state to not deliver power through the clutch. The clutch stack wear sensor system includes at least one detectable element arranged for movement in unison with the clutch piston and a sensor arranged to detect the detectable element and provide a signal indicative of a wear characteristic of the clutch stack.

A method of clutch wear notification comprises detecting engaged clutch positions at a first interval and storing the values of the engaged clutch positions. The stored values of the engaged clutch positions can be averaged at a second interval to create running averages, and the running averages can be stored. The running averages are compared at a third interval to determine a rate of change in the clutch positions. A clutch wear-out is signaled when comparing the running averages indicates that the rate of change in the clutch positions deviates from a normal rate of change. The clutch position during an engaged condition can deviate from the normal rate of change when the axial position of the release bearing begins to increase due to an adjustment mechanism ceasing to adjust.

A method is provided for balancing clutch wear in a dual clutch transmission. The method involves performing the steps of determining which clutch unit of first and second clutch units is subjected to the most accumulated wear and selecting a gear actuated by the other clutch unit during launch of the vehicle.

A transmission control device detects deterioration of a clutch that can adjust a connection or disconnection state between an engine output shaft and a first input shaft by a pressure of a hydraulic fluid supplied to a first hydraulic chamber. The transmission control device includes a supply control unit that supplies the hydraulic fluid such that the first hydraulic chamber has a predetermined pressure in a state of keeping rotational speed of the engine output shaft constant, a clocking processing unit that measures elapsed time since the supply control unit starts a supply of the hydraulic fluid to the first hydraulic chamber until a rotational speed of the first input shaft exceeds a predetermined rotational speed and determines whether the elapsed time exceeds a predetermined allowed time, and a deterioration determination unit that determines that the first clutch deteriorates in a case where the time elapsed exceeds the allowed time.

A clutch cylinder in a hydraulic pressure system can be charged with a controlled rotational speed of a pump to deliver hydraulic fluid into the clutch cylinder until a biting point of the clutch is reached and exceeded and a motor current of the pump has attained a predetermined minimum value. On the basis of a profile of the controlled rotational speed, a first volume of the hydraulic fluid delivered into the clutch cylinder by the pump up is determined until the minimum value is attained. The value of the first volume can be reduced by a predetermined amount to a second volume, which can be used for clutch processes during vehicle operation, wherein the second volume is delivered into the clutch cylinder, with a high rotational speed of the pump, such that the clutch is filled such that the biting point of the clutch is not quite reached.

A clutch plate and a clutch assembly for use in a powertrain of a vehicle, the clutch plate being configured to be connected for common rotation with a driven shaft extending in an axial direction, the clutch plate including a support member and a first friction member attached thereto, the first friction member having a first friction surface configured to face and selectively engage a corresponding second friction surface of a flywheel, the clutch plate further including an electrically conducting element extending from the first friction surface toward the support member in a direction having an axial component, the electrically conducting element being configured to be electrically connected to a terminal, so that, upon engagement of the first and second friction surfaces, an electric signal may be passed between the flywheel and the terminal via the electrically conducting element.

A clutch includes a clutch disk that rotates by receiving motive power from an engine and a clutch plate switched between an engaged state in which it is engaged with the clutch disk and a disengaged state in which it is not engaged with the clutch disk. A controller calculates a coefficient of friction ? between the clutch disk and the clutch plate based on a time period ?t elapsed from a first time point when the number of relative rotations of the clutch disk and the clutch plate attains to a first number of rotations to a second time point when a second number of rotations smaller than the first number of rotations is attained, in a state in which the clutch disk rotates while transfer of motive power from the engine to the clutch disk is cut off and in the engaged state.

A rotation transmission device includes a one-way clutch which is provided between an output shaft of a speed increaser and an input shaft of a generator, which makes a connection between the output shaft and the input shaft to be rotatable integrally in a state in which a rotation speed of the output shaft is higher than that of the input shaft, and which cuts off the connection between the output shaft and the input shaft in a state in which the rotation speed of the output shaft is lower than that of the input shaft. The rotation transmission device further includes: a measurement section which measures a state of the one-way clutch which changes depending on a load exerted to the one-way clutch; and an acquisition section which acquires the load exerted to the one-way clutch on a basis of a measurement result of the measurement section.