A hydrostatic actuator system includes an electric motor for delivering a hydraulic fluid via a piston unit. The actuator system is operating using a method in which a change in volume caused by a temperature change is sensed by a pressure measurement. The method reliably identifies a state of the transfer of the hydraulic fluid from a planetary roller transmission compartment into the master piston. The pressure measurement is continuously evaluated, and, in the event of a negative signal of the pressure measurement, suction of the hydraulic fluid by a planetary roller transmission lying in the hydraulic fluid between the electric motor and the piston unit into the piston unit is recognized and a fault signal is output.

A power transmission device includes a friction clutch, an actuator, and a controller configured to determine an approximated temperature change of the friction clutch. The controller is configured to determine a current power state of the friction clutch, determine a desired power state change based on the current power state and a previous power state, determine a plurality of thermal coefficients based on a thermal coefficient model, the desired power state change, and a set of operation variables, determine an approximated temperature change of the friction clutch based on the thermal coefficients and a friction clutch temperature model, determine an approximated clutch temperature based on the approximated temperature change and a contemporaneous value of an device ambient temperature, and control operation of the actuator based at least on the approximated clutch temperature.

A method for automatically warming up a clutch actuator for a clutch of a transmission in a vehicle, wherein the clutch actuator is operable by use of pressurized fluid and configured to actuate the clutch from an engaged to a disengaged state, and/or vice versa, the method including: identifying if a temperature is below a predetermined temperature value and if the clutch actuator is leaking, and if it is identified that the temperature is below the predetermined temperature value and that the clutch actuator is leaking; then repeatedly pressurizing the clutch actuator by use of the pressurized fluid until a state is reached indicative of the clutch actuator being functional, or until a maximum run out state is reached indicative of a faulty clutch actuator.

A method for automatically warming up a clutch actuator for a clutch of a transmission in a vehicle, wherein the clutch actuator is operable by use of pressurized fluid and configured to actuate the clutch from an engaged to a disengaged state, and/or vice versa, the method including: identifying if a temperature is below a predetermined temperature value and if the clutch actuator is leaking, and if it is identified that the temperature is below the predetermined temperature value and that the clutch actuator is leaking; then repeatedly pressurizing the clutch actuator by use of the pressurized fluid until a state is reached indicative of the clutch actuator being functional, or until a maximum run out state is reached indicative of a faulty clutch actuator.

An apparatus (a controller), and systems and methods for management of inputs, determination of a calculated clutch temperature, and control of action related to the clutch of a transmission system, and notification improvements to a user associated therewith are disclosed. In particular, a clutch calculator circuit is augmented by a machine learning component that employs a machine learning technique and provides a projected clutch temperature as a basis for actions to be taken.

A control device of a vehicle, the vehicle includes an engine, a hydraulic clutch disposed on a power transmission path between the engine and driving wheels, a starter motor for use in startup of the engine, an electric oil pump device discharging hydraulic oil generating oil pressure supplied to the clutch, and a power supply device supplying electric power driving each of the starter motor and the electric oil pump device. The control device includes a startup control unit that performs starter startup control of starting discharge of the hydraulic oil by the electric oil pump device after determining that output voltage of the power supply device or input voltage of the electric oil pump device is higher than or equal to a fixed voltage after completion of cranking by the starter motor upon startup of the engine using the starter motor.

A prime mover includes a stator fixed to the housing and a rotor rotatable relative to the stator. The prime mover outputs torque by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. A rotational translation unit includes a rotation portion that rotates relative to the housing upon receiving the torque from the speed reducer, and a translation portion that moves relative to the housing in an axial direction. A clutch allows torque transmission in an engaged state, and interrupts the torque transmission in a disengaged state. A state changing unit changes the state of the clutch by receiving a force along the axial direction from the translation portion. Cogging torque generated between the rotor and the stator is set to such a magnitude that the rotor is stoppable at any rotation position relative to the stator.

A prime mover includes a stator fixed to the housing and a rotor rotatable relative to the stator. The prime mover outputs torque by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. A rotational translation unit includes a rotation portion that rotates relative to the housing upon receiving the torque from the speed reducer, and a translation portion that moves relative to the housing in an axial direction. A clutch allows torque transmission in an engaged state, and interrupts the torque transmission in a disengaged state. A state changing unit changes the state of the clutch by receiving a force along the axial direction from the translation portion. Cogging torque generated between the rotor and the stator is set to such a magnitude that the rotor is stoppable at any rotation position relative to the stator.

A power transmission device includes a friction clutch, an actuator with an output member, and a controller. The friction clutch is lubricated with a lubricant. The controller is configured to determine a current power state of the friction clutch and determine values for a plurality of thermal coefficients based on the current power state, a set of operation variables, and one or more multi-variable correlation data. The controller is further configured to determine an approximated temperature change of the lubricant based on the values of the plurality of thermal coefficients and a lubricant temperature model. The controller is further configured to determine an approximated lubricant temperature based on the approximated temperature change and a device ambient temperature, and to control operation of the actuator based at least on the approximated lubricant temperature.

A hydrostatic actuator system includes an electric motor for delivering a hydraulic fluid via a piston unit. The actuator system is operating using a method in which a change in volume caused by a temperature change is sensed by a pressure measurement. The method reliably identifies a state of the transfer of the hydraulic fluid from a planetary roller transmission compartment into the master piston. The pressure measurement is continuously evaluated, and, in the event of a negative signal of the pressure measurement, suction of the hydraulic fluid by a planetary roller transmission lying in the hydraulic fluid between the electric motor and the piston unit into the piston unit is recognized and a fault signal is output.