A clutch assembly, a torque converter clutch assembly, and a brake assembly for a vehicle are disclosed. The clutch assembly and the brake assembly may have at least one reaction plate comprising an internal cavity containing a phase change material. The torque converter clutch assembly may have a front cover plate comprising an internal cavity containing a phase change material. The phase change material may be capable of absorbing at least some friction-induced heat generated at a friction interface of the reaction plate or front cover plate when the clutch assembly, the torque converter assembly, or the torque converter assembly is shifted to a closed position, such as when the clutch is activated or when the brakes are applied.

A releasable pneumatically operated coupling for an industrial drive such as for a grinding mill. A variable speed motor has its output shaft provided with a flange rotating therewith on which are mounted a plurality of radially moveable arcuate elements having friction pads on their radially inner surfaces. An inflatable ring surrounds the arcuate elements and, upon inflation, urges the pads into driving contact with an annular friction surface on a coupling output shaft. The arcuate elements have U-shaped undercuts in the axial torque bar passages therethrough for stress relief. Separate speed sensors on the motor shaft and coupling output shaft provide signals to a comparator which, upon sensing a predetermined speed difference, provide a signal to an electrically operated valve which exhausts air pressure from the inflatable ring to release the coupling.

Disclosed is a method for protecting a vehicle clutch, including a check step for checking the mileage of a vehicle and the number of times a clutch wear compensation device is operated; after the check step, a calculation step for calculating a clutch thermal severity level, which indicates the degree of thermal severity of the clutch, based on the mileage and the number of times the wear compensation device is operated; and a control step for controlling at least one of the shifting pattern of the vehicle and engine RPM depending on the clutch thermal severity level, after the calculation step.

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the dog clutch and the friction clutch. The controller starts the engagement of the dog clutch, after placing the dog clutch in a rotationally synchronized state by engaging the friction clutch and increasing an output rotation thereof, when there is a request to engage the dog clutch. In this clutch control device, the controller sets the engagement start timing of the friction clutch when a transition is made to the connected, four-wheel drive mode to an earlier timing compared to when a transition is made to the standby two-wheel drive mode, when there is a request to engage the dog clutch while in a state in which the disconnected, two-wheel drive mode is selected.

Disclosed is a method for protecting a vehicle clutch, including a check step for checking the mileage of a vehicle and the number of times a clutch wear compensation device is operated; after the check step, a calculation step for calculating a clutch thermal severity level, which indicates the degree of thermal severity of the clutch, based on the mileage and the number of times the wear compensation device is operated; and a control step for controlling at least one of the shifting pattern of the vehicle and engine RPM depending on the clutch thermal severity level, after the calculation step.

A hybrid drive including a first drive motor coupled by a clutch to a shaft, and a second drive motor coupled rigidly to the shaft. A method for determining the temperature of the clutch in the hybrid drive includes the steps of: determining a temperature of the clutch; determining a temperature of the clutch housing; determining the temperature difference between the clutch and the clutch housing; determining the heat conductivity between the clutch and the clutch housing, wherein the heat conductivity is determined as a function of the rotational speed of the first drive motor and the rotational speed of the second drive motor; determining the heat flow between the clutch and the clutch housing on the basis of the product of the heat conductivity and the temperature difference; and adjusting the ascertained clutch temperature on the basis of the ascertained heat flow.