Systems and methods for operating a power take off of a vehicle are described. In one example, operation of the power take off may be maintained even when slip of a power take off clutch is detected. In particular, the power take off may be operated at a lower output until the power take off may handle larger loads.

A method to estimate an amount of force in a clutch pack of a clutch actuation system. The method includes engaging an actuation motor to apply a set point force to the clutch pack and monitoring a position of the actuation motor when the set point force is applied. Additionally, the method includes determining one or more clutch clamping curves and one or more clutch releasing curves based on a relationship between the position of the actuation motor and an amount of torque applied by the actuation motor at position of the actuation motor. The method further includes modeling one or more frictional characteristics of the clutch actuation system and estimating an amount of clamping and releasing force within the clutch pack by using a control unit. The amount of torque applied to the clutch pack between the clutch clamping and releasing curves at the set point force is maintained.

An electromagnetic clutch (1) of an air conditioning compressor (2), in particular for a motor vehicle (11), transmits a torque to a drive shaft (3) of the compressor (2) depending on an electric current (I) being fed to clutch coils (4) of the electromagnetic clutch (1) to generate an electromagnetic clutch force. According to a control method (10), a slippage of the electromagnetic clutch (1) is determined by a difference between the rpms of the electromagnetic clutch (1) and of the drive shaft (3), and is monitored by a slippage sensor (5). The electric current (I) and the resulting clutch force are adjusted dependent on slippage by a pulse width modulation controller (6) of the compressor (2). The pulse width modulation controller (6) is electrically connected to the clutch coils (4) and modulates a pulse width of the electric current (I) fed to the clutch coils (4).

A friction engagement element control system is provided, which includes a friction engagement element including friction plates, which are an input-side friction plate and an output-side friction plate, and an actuation system configured to engage the input-side friction plate with the output-side friction plate with a pushing force, the friction plates having a characteristic in which a friction coefficient thereof decreases as a rotational difference between the friction plates increases. The device includes a controller configured to control the pushing force so that the negative slope characteristic becomes a positive slope characteristic in which a frictional force of the friction engagement element decreases as the rotational difference decreases, when engaging the friction engagement element.

A friction engagement element control system is provided, which includes a friction engagement element including friction plates, and an actuation system configured to engage an input-side friction plate with an output-side friction plate with a pushing force, the friction plates having a negative slope characteristic in which a friction coefficient thereof decreases as a rotational difference between the friction plates increases, a rotational difference sensor of the friction engagement element, a separator configured to divide a variation in the detected rotational difference into a high-frequency component that is a vibration component and other low-frequency components, and a controller configured to control a pushing force only for the vibration component of the rotational difference so that the negative slope characteristic becomes a positive slope characteristic in which a frictional force of the friction engagement element decreases as the rotational difference decreases, when engaging the friction engagement element.

A control system in a four-wheel-drive motor vehicle for the distribution of drive forces at least from a drive of the motor vehicle to wheels of the first and second axles of the motor vehicle, at least including: a distribution device for distributing the drive forces to the first and second axles; rotation rate sensors for detecting the rotation rate of the two axles and/or the wheels of the motor vehicle, a central control device that is connected to a distribution controller and the sensors and a vehicle communication system, wherein the distribution controller is attached to the distribution unit and performs control both to a setpoint torque and to a setpoint rotation rate, and thus—in a drive-dependent and switchable manner—determines a distribution ratio of the drive forces to be distributed to the first and second axles on the basis of the ratio between the torque and the setpoint torque or between the setpoint rotation rate and the setpoint rotation rate.

A vehicle drive device includes: an electric motor; a multi-plate clutch including a plurality of clutch plates; a pressing mechanism configured to press the multi-plate clutch; an output rotary member to which a drive force of the electric motor is transferred through the multi-plate clutch; and a control device configured to control the electric motor and the pressing mechanism. The control device is configured to control the pressing mechanism using information on the result of test operation performed while the vehicle is stationary.

The present invention relates to a saddle-ride type vehicle comprising a clutch assembly (4), interposed between an engine (2) and a gearbox (3), which includes a clutch device (11) in turn comprising two clutch elements (one integral with the shaft of the engine and the other with the input shaft of the gearbox) and return means (12) that keep these elements (11A, 11B) in contact in a closure condition of the clutch. According to the invention, the clutch assembly (4) further comprises an operating device (21) of the clutch device that causes detachment of the elements (11A, 11B) of the clutch device up to an opening condition of the clutch assembly. This latter further comprises a control device (6) to limit the torque peaks during gear change. This device comprises an actuation means (5) that, during gear change, exerts a predetermined force (S) in contrast to the force exerted by said return means (12) of the clutch assembly, wherein said predetermined force (S) is less than the force (F) generated by the return means (12) so as to cause a mutual slip of the elements (11A, 11B) of the clutch device (11) without said opening condition being reached. The operating device (21) is of hydraulic type and comprises a primary pump (22) operated by means of a control lever (23), wherein this primary pump (22) is hydraulically connected, through a primary hydraulic circuit (16), to a primary piston (24) acting on at least one of the elements (11A, 11B) of the clutch device (11) in opposition to the return means (12) so that, following an action on the control lever (23), the primary piston (24) exerts an action the elements (11A, 11B) determining the opening condition. According to the invention, the control device (6) comprises a secondary piston (25) connected to the primary piston (24), wherein the actuation means (5) exerts, directly or indirectly, the predetermined force (S) on the secondary piston (25), said predetermined force (S) being transferred to the primary piston (24) in opposition to the force (F) of the return means (12).

A method for synchronizing a first drive element rotatable about an axis of rotation with a second drive element rotating about the axis of rotation at a target speed, of a powertrain of a motor vehicle, in which a synchronizing force is exerted on a synchronizing unit by an actuator. A speed, at which the first drive element rotates about the axis of rotation is adapted by the synchronizing unit to the target speed. The synchronizing force is increased during a first time span, so that the speed approaches the target speed. The synchronizing force is continuously reduced during a second time span following the first time span, before the speed corresponds to the target speed.

The invention relates to an electrically driven clutch actuators (1) for actuating the clutch of a transmission of a vehicle. An actuator comprises a spindle nut (11) on a spindle (9) and a pressure piece (13) displaceable relative to the spindle nut (11) and coupled to the spindle nut by a biasing spring (15). By rotation of the threaded spindle under a driving force of an electric motor (5), the spindle nut (11) compresses the biasing spring (15) and displaces the pressure piece (13) to disengage the clutch. A latching mechanism (16) is configured to limit displacement of the spindle nut away from the pressure piece under the force of the expanding biasing spring when the driving force is reduced below a predetermined level. Further, a control unit is described that reduces the driving force in response to a trigger condition to reduce power consumption in the clutch disengaged state.