A control device for an automatic transmission includes a continuously variable transmission mechanism, a torque converter, a target transmission ratio calculation unit, a feedback control unit, and a phase compensation unit. The torque converter has a lock-up clutch. The target transmission ratio calculation unit is configured to calculate a target transmission ratio based on a travelling state. The feedback control unit is configured to perform feedback control based on an actual value indicative of a state of the continuously variable transmission mechanism. The phase compensation unit is configured to perform phase lead compensation of the feedback control based on the travelling state. The phase compensation control unit is configured to halt the phase lead compensation when an unstable travelling state of a vehicle is detected. The phase compensation control unit is further configured to release the lock-up clutch when the phase lead compensation is halted.

A method for operating an idling automatic transmission of a motor vehicle having a torque converter, wherein the torque converter comprises at least one pump wheel and a turbine wheel which are designed to transmit a torque hydrodynamically from one to the other. The method comprises at least the following steps: determinating (12) a rotation speed of the turbine wheel; determinating (14) a load on the motor of the motor vehicle; and recognizing (16) whether there is a blockage in the drive-train of the motor vehicle or whether the torque converter is running dry, as a function of the turbine rotation speed and the motor load detected. The invention also relates to a monitoring device (10).

A control device controls a lockup clutch interposed between an engine and an automatic transmission mechanism of a vehicle. The control device includes a control part supplying hydraulic pressure to the lockup clutch and controlling differential pressure of the lockup clutch. The control part supplies the hydraulic pressure to the lockup clutch so that the differential pressure is lower than a reference differential pressure in a disengaged state of the lockup clutch. In a case of shifting the lockup clutch from the disengaged state to an engaged state, the control part supplies the hydraulic pressure to the lockup clutch so that the differential pressure increases as a filling ratio of an oil passage of the lockup clutch decreases. The reference differential pressure is a lower limit of the differential pressure that increases a slip ratio of the lockup clutch or reduces a slip amount of the lockup clutch.

A method for operating a drive-train of a motor vehicle. The drive-train having a transmission connected between a drive aggregate and a drive output. A hydrodynamic starting element is connected between the drive aggregate and transmission. The starting element includes a converter and converter lock-up clutch. A Power Take-Off (PTO) can be coupled to the drive aggregate on the drive aggregate side to take up drive torque delivered by the drive aggregate. In order to determine the torque taken up by the PTO, the lock-up clutch is operated in a rotational-speed-regulated manner at least when the PTO is coupled to the drive aggregate in order to set a defined target slip at the lock-up clutch. As a function of the actuation pressure of the lock-up clutch required for setting the target slip when the PTO is coupled, the torque taken up by the PTO is determined.

The lock-up control unit is configured to: in a case where the normal mode is selected, disengage the lock-up clutch when a vehicle speed decreases and reaches a first vehicle speed while the vehicle is traveling in a state where the lock-up clutch is engaged, in a case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a second vehicle speed in a brake operation OFF state while the vehicle is traveling in the state where the lock-up clutch is engaged, in the case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a third vehicle speed in a brake operation ON state while the vehicle is traveling in the state where the lock-up clutch is engaged, and set the third vehicle speed to a vehicle speed lower than the first vehicle speed, and set the second vehicle speed to a vehicle speed higher than the first vehicle speed.

The lock-up control unit is configured to: in a case where the normal mode is selected, disengage the lock-up clutch when a vehicle speed decreases and reaches a first vehicle speed while the vehicle is traveling in a state where the lock-up clutch is engaged, in a case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a second vehicle speed in a brake operation OFF state while the vehicle is traveling in the state where the lock-up clutch is engaged, in the case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a third vehicle speed in a brake operation ON state while the vehicle is traveling in the state where the lock-up clutch is engaged, and set the third vehicle speed to a vehicle speed lower than the first vehicle speed, and set the second vehicle speed to a vehicle speed higher than the first vehicle speed.

A torque convertor and direct drive unit arrangement and operating methods are provided herein. In one example, a prime mover may be configured to be coupled to a transmission via one of a torque convertor and a direct drive unit, the direct drive unit including a higher range clutch and a lower range clutch.

The disclosure provides a control method, a control device for vehicular automatic transmission, and a recording medium. The control device includes an ON/OFF control solenoid controlling LC to either ON or OFF, and an LC pressure control linear solenoid controlling LC pressure between a released state and a fully engaged state. The control device acquires, when an accelerator pedal opening of a vehicle is on a deceleration side in a fully closed state, a torque converter slip ratio when the ON/OFF control solenoid maintains ON for a predetermined time period and the LC pressure control linear solenoid is controlled such that the LC pressure is OFF, and determines whether or not the second solenoid has a high-pressure fixation failure according to whether or not the slip ratio is within a predetermined range from a slip reference value.

A transmission assembly and a method of assembling a transmission assembly that is located between the engine block and the transmission gearbox is provided. The assembly includes a hub having a fluid path for a clutch and a hub flange, a torque converter cover formed with extruded studs in an area adapted to be connected to the hub flange, the extruded studs including a circumferential outer surface having a plurality of serrations, holes in the hub flange in locations corresponding to locations of the extruded studs, with a respective inside diameter of each of the holes being smaller than an outside diameter of the studs; and the hub being connected to the torque converter cover with the studs engaging in the holes in the hub flange with an interference fit.

In a power transmission device, a dynamic damper is provided in a power transmission path having at least one damper disposed therein, and has an inertial rotating body that can rotate relative to a transmission rotating member forming part of the power transmission path, and a dynamic damper spring that can provide connection between the transmission rotating member and the inertial rotating body. A preset load is applied to the dynamic damper spring in a non-transmitting state of the power transmission path. The dynamic damper spring is supported on either one of the transmission rotating member and the inertial rotating body so as to apply the preset load to the dynamic damper spring in the non-transmitting state, and a gap is set in a rotational direction in the non-transmitting state between the dynamic damper spring and an other one of the transmission rotating member and the inertial rotating body.