A torque limiter device includes an input shaft having a first contact surface and an output shaft having a second contact surface. The input and output shafts are operable in an engaged position and a disengaged position A biasing mechanism provides a bias force that mechanically biases the input and output shafts in one of the positions and sets a threshold torque. An electromagnet is arranged to selectively provide an electromagnetic force that opposes the bias force when an activation current is supplied. A controller determines a difference in rotations of the shafts and selectively supply the activation current to the electromagnet so as to disengage the input and output shafts when the rotation difference exceeds a threshold. Each of the contact surfaces comprises one or more grooves, wherein at least one rotatable member is disposed in at least one of said grooves.

A driving force transmission control device includes a driving force transmission device configured to press a friction clutch by an actuator and a controller configured to control the driving force transmission device. The controller calculates a torque command value indicating a driving force to be transmitted from a rotating member on an input side to a rotating member on an output side based on information of a vehicle. The controller sets an electric current command value according to a magnitude and an amount of time change of the torque command value. The electric current command value is a target value of an electric current. The controller performs electric current feedback control such that an electric current corresponding to the calculated electric current command value is supplied to the actuator.

Methods and systems for operating a plurality of electrical loads are described. In one example, the systems include electrical circuits for operating solenoid valves of a transmission that may be operated to simultaneously control two or more clutches for engaging and disengaging transmission gears. The systems and method may reduce hardware costs.

A torque limiter device includes an input shaft having a first contact surface and an output shaft having a second contact surface. The input and output shafts are operable in an engaged position wherein the contact surfaces are brought into mechanical engagement, and a disengaged position wherein the contact surfaces are separated. A biasing mechanism provides a bias force that mechanically biases the input and output shafts in one of the positions and sets a threshold torque. An electromagnet is arranged to selectively provide an electromagnetic force that opposes the bias force when an activation current is supplied. A rotation sensor arrangement measures a respective rotation of the input shaft and of the output shaft. A controller determines a difference in rotations of the shafts and selectively supply the activation current to the electromagnet so as to disengage the input and output shafts when the rotation difference exceeds a threshold.

The present invention is a hydraulic pressure control device for an automatic transmission that performs a gear shift by switching between engagement and disengagement of a plurality of friction engagement elements and includes solenoid valves, provided corresponding to the friction engagement elements, respectively, that switches between engagement and disengagement of the friction engagement elements by switching between supply and non-supply of hydraulic pressures to the friction engagement elements, and a control device that switches between supply and non-supply of the hydraulic pressures to the friction engagement elements by supplying a predetermined control current to the solenoid valves, in which the control device supplies a fixation preventing current lower than the control current to at least one of the solenoid valves corresponding to the friction engagement elements in a disengagement state of the plurality of friction engagement elements.

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.

Methods and systems are provided for operating an electromagnetic pulse disconnect assembly for selectively engaging two rotating components of a vehicle drivetrain. A disconnect assembly is needed that is not powered by vacuum diverted from an engine of the vehicle, as modern engines are being developed to reduce vacuum production and remove vacuum lines for powering peripheral devices such as disconnects. An electromagnetic pulse disconnect assembly is provided that operates via pulses of electrical current and includes an electromagnetic coil for translating a clutch ring assembly and a latching ring assembly to selectively couple two rotating components.

Methods and systems are provided for operating an electromagnetic coil assembly. As one example, a method comprises responsive to energization of an electromagnetic coil of an electromagnetic coil assembly, translating the electromagnetic coil along a central axis of the electromagnetic coil assembly toward a magnetic armature while maintaining the armature fixed along the central axis. The electromagnetic coil assembly may be utilized within various clutching, braking, or lever applications.

A system for a vehicle includes a desired pressure module, a valve actuation module, a filter module, and a capacity detection module. The desired pressure module selectively generates an increase in a desired pressure of hydraulic fluid for a clutch of an automatic transmission. The valve actuation module actuates a solenoid valve based on the desired pressure. The solenoid valve supplies hydraulic fluid to a regulator valve, and the regulator valve supplies hydraulic fluid to the clutch. The filter module filters an acceleration of a shaft of the automatic transmission to generate a filtered acceleration. The capacity detection module indicates whether the clutch reached torque carrying capacity based on the filtered acceleration.

Actual pressure of a hydraulic clutch of a motor vehicle can be regulated by: a) providing a value for a desired pressure to be present in a clutch cylinder; b) filling the clutch cylinder with hydraulic fluid to achieve the desired pressure; c) wherein, if the desired pressure lies between 0 and 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a rotational speed of the pump of the electric motor, and if the desired pressure is greater than 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a motor current of the electric motor; d) regulating the actual pressure until the desired pressure is achieved.