In a transmission structure according to this invention, speed change ratios of input side first and second transmission mechanisms are set so that the rotational speed of a planetary second element is the same when an HST output is set to a second HST speed in either a first transmission state or a second transmission state, and the rotational speed of a planetary first element is the same when the HST output is set to the second HST speed in either the second transmission state or the first transmission state. The speed change ratios of an output side first and second transmission mechanisms are set so that the rotational speed developed in a speed change output shaft when the HST output is set to the second HST speed is the same in either the first or second transmission states.

In a transmission structure according to this invention, speed change ratios of input side first and second transmission mechanisms are set so that the rotational speed of a planetary second element is the same when an HST output is set to a second HST speed in either a first transmission state or a second transmission state, and the rotational speed of a planetary first element is the same when the HST output is set to the second HST speed in either the second transmission state or the first transmission state. The speed change ratios of an output side first and second transmission mechanisms are set so that the rotational speed developed in a speed change output shaft when the HST output is set to the second HST speed is the same in either the first or second transmission states.

A control system for mixing materials for livestock feed including a container that receives the materials, agitators that mix the materials in the container, a driveline that drives the agitators at an output speed with an output torque, a power source that provides an input speed at an input torque, a continuously variable transmission that connects the driveline and the power source and having a hydrostatic loop to provide a speed ratio between the input speed and the output speed, a plurality of sensors positioned between the power source and the agitators that provides mixing signals commensurate to mixing parameters, and an electronic control unit configured to receive the mixing signals, extract mixing parameter values from the mixing signals, and actuate the continuously variable transmission and adjust the speed ratio based on the mixing parameter values to enhance efficiency of the mixing of the materials.

A method for providing a high drivability control system for an agricultural or industrial vehicle having an engine and a continuously variable transmission (CVT) includes setting a maximum speed target (MST), and setting a vehicle speed percentage (VSP) according to input using a desired speed input. A target engine speed, a target rate of change of the engine speed, a target CVT ratio, and a target rate of change of the target CVT ratio is then calculated from the VSP, the MST, and the present engine speed. The target engine speed may be further calculated from the present vehicle speed and/or the present CVT ratio.

A method for providing a high drivability control system for an agricultural or industrial vehicle having an engine and a continuously variable transmission (CVT) includes setting a maximum speed target (MST), and setting a vehicle speed percentage (VSP) according to input using a desired speed input. A target engine speed, a target rate of change of the engine speed, a target CVT ratio, and a target rate of change of the target CVT ratio is then calculated from the VSP, the MST, and the present engine speed. The target engine speed may be further calculated from the present vehicle speed and/or the present CVT ratio.

An electromagnetic valve control device includes a current gear ratio obtainer to obtain a current gear ratio as a ratio of an output revolutions number of a driver and an output revolutions number of a transmission, a current electric current value obtainer to obtain a current electric current value as a value of an electric current to be inputted to a first electromagnetic valve or a second electromagnetic valve, and a switching controller to, based on the current electric current value and a gear ratio difference as a difference between a target gear ratio and the current gear ratio, perform electromagnetic valve switching control to switch between use of the first electromagnetic valve to control a pump swash plate and use of the second electromagnetic valve to control the pump swash plate.

A continuously variable powertrain device for a work vehicle includes a hydraulic static transmission to output a continuously shifted motive power while continuously varying a velocity of a motive power received from an engine, a planetary transmission to receive the motive power from the engine and the continuously shifted motive power and to output a compound motive power, a pressure detector to detect a hydraulic pressure in a closed circuit of the hydraulic static transmission, a planetary clutch mechanism to switch a shift level of the planetary transmission, and a powertrain controller to control actuation of the hydraulic static transmission and the planetary transmission based on a shift command.

A method for controlling a gear ratio of a continuously variable transmission vehicle includes: a step of detecting a position of a shift lever by a controller; a step of checking, by the controller, a gear ratio variation based on a difference between a desired stage gear ratio and a current gear ratio in a continuously variable transmission when the shift lever is detected to be positioned in a manual range; a step of calculating, by the controller, a gear ratio correction value based on a rate of change of engine RPM when the gear ratio variation is checked as being other than zero after the step of checking the gear ratio variation; and a step of correcting, by the controller, the gear ratio variation in response to the calculated gear ratio correction value after the calculation step.

A method for controlling a gear ratio of a continuously variable transmission vehicle includes: a step of detecting a position of a shift lever by a controller; a step of checking, by the controller, a gear ratio variation based on a difference between a desired stage gear ratio and a current gear ratio in a continuously variable transmission when the shift lever is detected to be positioned in a manual range; a step of calculating, by the controller, a gear ratio correction value based on a rate of change of engine RPM when the gear ratio variation is checked as being other than zero after the step of checking the gear ratio variation; and a step of correcting, by the controller, the gear ratio variation in response to the calculated gear ratio correction value after the calculation step.

According to the present invention, there is provided a method of reducing output torque deficits during the launch of a vehicle having a continuously variable transmission, wherein the variator has an input connected to a prime mover and an output. The method comprises the steps of determining a rate of change of ratio in the transmission, and predicting a required motor speed ratio rate of change value of the variator on the basis of: (i) the determined rate of change of ratio in the transmission, and (ii) the configuration of the transmission. The speed of the variator output is adjusted so as to achieve the required motor speed ratio rate of change value.