A power transmission device includes an input shaft, an output shaft, a differential device, a continuously variable transmission unit, and a control device. The differential device includes a first rotation element connected to the input shaft, a second rotation element connected to the output shaft, and a third rotation element. The continuously variable transmission unit includes a conversion unit configured to convert rotational power of the third rotation element into an other power, and a reconversion unit configured to reconvert the converted other power into the rotational power and supply the reconverted rotational power to the output shaft. The control device includes a continuously variable transmission control unit configured to generate a control signal of the continuously variable transmission unit such that the other power generated by the conversion unit exceeds the other power input to the reconversion unit.

Methods and systems for a vehicle transmission are provided. An electromechanical transmission system includes, in one example, a power take-off (PTO) clutch configured to, in a first position, permit a motive power source shaft to solely drive a PTO. The PTO clutch is further configured to, in a second position, permit a first electric machine and a second electric machine to continuously vary a torque that is supplied to the PTO by the motive power source shaft.

A power-split hydro-mechanical hybrid transmission system with an automatic adjustment function includes an input member, a hydraulic transmission mechanism, a split mechanism, a convergence mechanism, an output member, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to an input end of the split mechanism, connects an output end of the split mechanism to an input end of the hydraulic transmission mechanism and an input end of the convergence mechanism, and connects an output end of the hydraulic transmission mechanism to the output member. An output end of the convergence mechanism is connected to the output member. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member. The power-split hydro-mechanical hybrid transmission system enables multi-mode continuously variable transmission and has energy reuse and emergency support functions.

A transmission system for a vehicle having a belt drive transmission. The belt drive has an adjustable input and output ratio, where the output of the belt drive is provided as a first input to a differential coupling. A further rotating connection is provided as a second input to the differential coupling, so that the output of the differential coupling is arranged as the output of the transmission system. Accordingly, the transmission output is based on the aggregate sum of the rotation of the first and second inputs to the differential coupling, wherein adjustment of the input and output ratio of the belt drive allows for a continuously variable transmission system.

An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

Systems and methods for controlling transmissions having CVTs are disclosed with multiple modes and gearing arrangements for range enhancements, where embodiments include synchronous shifting to allow the transmission to achieve a continuous range of transmission ratios, while minimizing “empty” cycling of the CVT during mode shifts. Embodiments provide for wide ratio range and performance and efficiency flexibility, while maximizing CVT usage through synchronous shifting.

A transmission system for a feed mixer including a continuously variable transmission (CVT) is provided. The CVT includes a mechanical loop and a hydrostatic loop. The CVT is operated so that the mechanical portion of the CVT is prevented from overtaking the hydrostatic portion of the CVT at start up of the CVT.

A hydro-mechanical hybrid transmission device with an energy management mechanism includes an input member, a mechanical transmission mechanism, an energy management mechanism, a power output mechanism, an output member, a convergence mechanism, a start mechanism, a hydraulic transmission mechanism, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to the mechanical transmission mechanism, the power output mechanism, and the hydraulic transmission mechanism, and connects the energy management mechanism to the mechanical transmission mechanism and the power output mechanism. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member and/or the power output mechanism, between the energy management mechanism and the output member and/or the power output mechanism, and between the energy management mechanism together with the input member and the output member and/or the power output mechanism.

Methods and systems for a hydromechanical transmission are provided. In one example, the method includes responsive to rotation of a portion of a mechanical assembly induced by cranking of an engine, blocking an output shaft of the hydromechanical transmission via joint engagement of a forward drive clutch and a reverse drive clutch. The method further includes pressurizing a hydrostatic assembly while the forward drive clutch and the reverse drive clutch remain jointly engaged, where the mechanical assembly is coupled in parallel with the hydrostatic assembly.

A power-split hydro-mechanical hybrid transmission system with an automatic adjustment function includes an input member, a hydraulic transmission mechanism, a split mechanism, a convergence mechanism, an output member, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to an input end of the split mechanism, connects an output end of the split mechanism to an input end of the hydraulic transmission mechanism and an input end of the convergence mechanism, and connects an output end of the hydraulic transmission mechanism to the output member. An output end of the convergence mechanism is connected to the output member. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member. The power-split hydro-mechanical hybrid transmission system enables multi-mode continuously variable transmission and has energy reuse and emergency support functions.