A continuously variable transmission (CVT) is provided for use on a recreational or utility vehicle. The CVT is electronically controlled by at least one control unit of the vehicle. The CVT includes a primary clutch having a first sheave and a second sheave moveable relative to the first sheave. An actuator controls movement of the second sheave.

Disclosed is lateral pressure control of a continuously variable transmission (CVT) with a transmission ratio changed by changing groove widths of a drive pulley and a driven pulley, a drive force from a drive source being transmitted to a wheel. A control part controlling respective lateral pressures of the drive pulley and the driven pulley is provided. The control part sets an increase correction amount of the lateral pressure of the drive pulley to a first lateral pressure increase correction amount if the CVT is not in an in-gear state or a shift position is consistent with a traveling direction of the vehicle, and, sets said amount to a second lateral pressure increase correction amount smaller than the first lateral pressure increase correction amount if the CVT is in the in-gear state and the shift position is not consistent with the traveling direction of the vehicle.

Provided is a control device for a continuously variable transmission, which is capable of effectively preventing occurrence of surge pressure due to a stroke of a driven pulley being stopped by abutment. The control device for the continuously variable transmission includes a pressure regulating valve regulating an oil pressure of oil supplied from an oil supply source to a cylinder chamber of the driven pulley, a control valve controlling the pressure regulating valve, and a control part controlling the control valve. If the control part determines that a gear ratio of the continuously variable transmission is maximum, as a first condition, when an instructed oil pressure of the control valve for the pressure regulating valve is larger than an oil pressure of oil supplied from the pressure regulating valve to the driven pulley, a control for lowering the instructed oil pressure is performed.

A vehicle includes an engine, a continuously variable transmission including an endless belt to output a power from the engine, and a transmission to which the power from the continuously variable transmission is transmitted. If the vehicle travel speed is not smaller than a first threshold value and an accelerator opening degree is not smaller than a second threshold value, a controller determines that the continuously variable transmission is being used in a belt high-load situation. If a travel distance in the belt high-load situation is not smaller than a third threshold value, the controller determines that the endless belt is deteriorated or deterioration thereof is in an advanced stage, and a deterioration message about the endless belt is displayed on a display based on an instruction from the controller. A situation in which a speed changing ratio of the continuously variable transmission is not greater than a fourth threshold value may be determined as the belt high-load situation.

A vehicle control device for controlling a vehicle with a drive source, a friction transmission mechanism provided between the drive source and drive wheels and a fluid transmission mechanism provided between the friction transmission mechanism and the drive source includes a suppression unit configured to suppress a decrease of a speed ratio of the fluid transmission mechanism if the speed ratio becomes negative when the vehicle starts.

Ground wires are shared between a drive-side pulley solenoid valve and a driven-side pulley solenoid valve. Therefore, when a disconnection or short circuit occurs in the shared portion, a drive-side pulley and a driven-side pulley show substantially the same behavior. As a result, changes in the speed ratio γcvt of a continuously variable transmission are suppressed and changes in vehicle behavior are also suppressed. Therefore, it is possible to suppress the degradation of drivability during the failure of the solenoid valves involved in power transmission.

A vehicle control system is provided to improve a response and an acceleration feel of a vehicle having a continuously variable transmission. The vehicle control system is configured to control an output power of a prime mover and a speed ratio of a transmission in such a manner that an actual driving force is increased stepwise to the required driving force to be achieved by a kick-downshifting so as to temporarily hold an increase in an acceleration during execution of the kick-downshifting.

A vehicle includes a power plant, continuously variable transmission (CVT), drive wheels, sensors, and controller. The CVT achieves a fixed gear/positive engagement and friction drive modes, and includes an input member that receives input torque from the power plant, an output member, and a variator assembly having drive and driven variator pulleys. The pulleys are connected to each other via an endless rotatable drive element, and to a respective one of the input and output members. Pulley actuators change a CVT speed ratio. The controller calculates a relative slip of the pulleys using measured speeds and displacements from the sensors, reduces the relative slip until the relative slip is below a calibrated speed limit or within a calibrated speed range via actuator control signal to the pulley actuators, and commands the fixed gear/positive engagement mode via positive engagement control signals to the CVT until the relative slip reaches zero.

Control system for a continuously variable transmission with a first and a second pair of conical sheaves each with adjustable running radius, in which of each pair at least one sheave (14a, 14b) is coupled to a first and a second hydraulic actuator (20a, 20b) respectively which sets the axial sheave position in dependence of the amount of hydraulic medium supplied thereto, in which the actuators are connected with means to supply and discharge thereto/therefrom respectively, hydraulic medium, and one actuator is connected to a source of hydraulic pressure medium, and in which furthermore the first and second actuator respectively is connected with a first and second control chamber (60, 124) respectively, filled with hydraulic medium and having a variable control volume, in such a way that an increase of the first control volume is coupled to a decrease of the second control volume, and vice versa.

A control apparatus for a vehicular drive unit is provided. The vehicular drive unit includes a continuously variable transmission, and a clutch. The control apparatus includes an electronic control unit that is configured to acquire an oil temperature of hydraulic oil for controlling the continuously variable transmission and the clutch, and control the clutch such that a torque capacity of the clutch becomes smaller than a torque capacity that is set in a case where an oil temperature of the hydraulic oil is higher than a predetermined oil temperature, when the oil temperature is equal to or lower than the predetermined oil temperature, or control the continuously variable transmission such that a speed ratio of the continuously variable transmission becomes equal to or larger than a lower limit set in advance when the oil temperature of the hydraulic oil is equal to or lower than the predetermined oil temperature.