A power transmission device has a reverse torque converter and a planetary gear mechanism with a ring gear, sun wheel and planet carrier with several planets. An input is connected to an impeller of the reverse torque converter and to a first element of the planetary gear mechanism. A turbine wheel is connected to a second element of the planetary gear mechanism, and a third element of the planetary gear mechanism is connected to or forms an output of the power transmission device. A selectable control clutch transmits power in a first rotation speed range, with an emptied reverse torque converter, between the input and the output of the power transmission device. A device supports and/or fixes the second element of the planetary gear mechanism, in particular the connection between the turbine wheel and the second element of the planetary gear mechanism in this first rotation speed range.

A hydrodynamic machine has a working chamber that may be filled with a working medium and in which a bladed pump impeller and a bladed turbine impeller are arranged to hydrodynamically transmit torque and/or drive power from the pump impeller to the turbine impeller. A working medium inlet and a working medium outlet are provided for inputting and discharging the working medium in/out of the working chamber. A control valve is furnished in the working medium inlet or in a bypass. The control valve changes the working medium quantity flowing into the working chamber. The control valve is connected to the working medium inlet and/or the working medium outlet and actuated such that the flow cross-section of the control valve is variably adjusted as a function of the working medium pressure in the working medium inlet and as a function of the working medium pressure in the working medium outlet.

A torque converter system of a vehicle for delivering an input torque to a transmission may include a front cover of a torque converter receiving the input torque through a torque receiving shaft, an impeller of the torque converter receiving the input torque through the front cover, a turbine of the torque converter disposed opposed to and coaxially with the impeller and rotated by an operation fluid supplied from the impeller thereby driving a transmission input shaft, a reactor of the torque converter disposed between the impeller and the turbine and redirecting the operation fluid from the turbine toward the impeller, and a lock-up clutch disposed inside a transmission to selectively connecting the front cover and the turbine.

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.

A method operates a drive train for driving a working machine with variable rotation speed. The method includes running up the electric drive machine from a standstill with evacuated hydrodynamic rotation speed/torque converter to a predefined value which indirectly characterizes the operating mode of the drive machine. Simultaneously with reaching the predefined value which indirectly characterizes the operating mode of the drive machine or with a temporal offset after reaching this, filling the hydrodynamic rotation speed/torque converter and driving the turbine vane wheel. Thereafter, the third element of the planetary gear mechanism is driven with a rotation speed which results from a superposition, defined by the planetary gear mechanism, of the rotation speed of the first element of the planetary gear mechanism connected to the electric drive machine and the rotation speed of the second element of the planetary gear mechanism which is indirectly connected to the turbine wheel.

A method performs shifts in a dog clutch element of a transmission system in a hybrid vehicle. The vehicle has an input shaft being connected to a crankshaft of an internal combustion engine, an output shaft being connected indirectly to driven wheels, an electric machine which is in engagement with the input shaft, and an automatic transmission connected between the input and output shafts. The transmission has a dog clutch element for the releasable coupling of two transmission elements. During a desired shifting of the dog clutch element, the torque of the input shaft is adapted via the electric machine, and therefore a reduced load prevails in the region of the dog clutch element and the latter can be disengaged, after which the internal combustion engine is set to a desired target rotational speed, and after which the dog clutch element is engaged when the target rotational speed is reached.

A method for shifting an automatic transmission, including a drive region, a hydrodynamic converter, an output region, and exactly one planetary gear that acts in a first operating state and a second operating state. In order to shift to different gears of the automatic transmission, different transmission ratios are set in the strictly mechanical power branch by disengaging and engaging clutches and/or brakes in the drive region. The planetary gear set in the output region in the case of at least two different transmission ratios in the strictly mechanical power branch, the rotational movement transmitted by the strictly mechanical power branch is stepped up, in order to always set additional gears.

A variable speed torque converter comprising an impeller, a plurality of housings, a set of planetary gear including a planet carrier, a valve block, a sun gear, a set of inner and outer planet gears, and a turbine, wherein the variable speed torque converter is configured such that the housing drives a set of inner planet gears configured to drive a sun gear, which drives the impeller, wherein the impeller pumps transmission fluid to the turbine to drive the turbine, and the turbine drives the valve block to increase rotational speeds of the inner planet gears via the outer planet gears.

Split power hydro-mechanical transmission includes an input shaft and an output shaft, a torque converter and a planetary gear, wherein the input shaft is connected to the turbine rotor and the ring gear or the sun gear, the pump rotor is connected to the sun gear or the ring gear, and the output shaft is connected to the planet carrier. This arrangement introduces strong positive feedback between the pump rotor and the turbine rotor, which results in large maximum torque ratio and large rate of growth of torque ratio, as well as large range of (naturally automatic) torque ratio variation.

A power transmission device includes a hydrodynamic converter. The blading of the pump wheel and/or turbine wheels includes at least one adjusting blade which can be actuated by an adjusting device, and/or at least one multi-element blade having at least one adjustable blade segment.