A power-on/off command is output to a breaker for switching when a frequency difference between a plurality of electric power supply sources is within a predetermined range and a phase difference between the plurality of electric power supply sources is within a predetermined range, in switching of electric power supply between the plurality of electric power supply sources. A generator drive rotation speed of a transmission device is feedback controlled so that the frequency difference is maintained at a value within the predetermined range and the phase difference is maintained at a value within the predetermined range when the detected frequency difference is within the predetermined range and the detected phase difference is within the predetermined range. A generator rotation speed command is calculated by adding to the rotation speed command of the transmission device an output value obtained by subjecting the detected phase difference to a proportional-integral-control.

A power-on/off command is output to a breaker for switching when a frequency difference between a plurality of electric power supply sources is within a predetermined range and a phase difference between the plurality of electric power supply sources is within a predetermined range, in switching of electric power supply between the plurality of electric power supply sources. A generator drive rotation speed of a transmission device is feedback controlled so that the frequency difference is maintained at a value within the predetermined range and the phase difference is maintained at a value within the predetermined range when the detected frequency difference is within the predetermined range and the detected phase difference is within the predetermined range. A generator rotation speed command is calculated by adding to the rotation speed command of the transmission device an output value obtained by subjecting the detected phase difference to a proportional-integral-control.

A toroidal continuously variable transmission includes: input and output discs; a power roller sandwiched between the input disc and the output disc so as to be tiltable; a trunnion supporting the power roller and configured to be tiltable about a tilt axis of the power roller and reciprocatable in a direction along the tilt axis; a piston attached to a shaft portion of the trunnion so as to be externally fitted to the shaft portion; and a cylinder forming a pressure chamber which makes the piston reciprocate in the direction along the tilt axis. An inside gap is formed between an outer peripheral surface of the shaft portion of the trunnion and an inner peripheral surface of the piston.

A toroidal continuously variable transmission includes: input and output discs; a power roller sandwiched between the input disc and the output disc so as to be tiltable; a trunnion supporting the power roller and configured to be tiltable about a tilt axis of the power roller and reciprocatable in a direction along the tilt axis; a piston attached to a shaft portion of the trunnion so as to be externally fitted to the shaft portion; and a cylinder forming a pressure chamber which makes the piston reciprocate in the direction along the tilt axis. An inside gap is formed between an outer peripheral surface of the shaft portion of the trunnion and an inner peripheral surface of the piston.

In a transmission device, a power roller transmits a rotational driving force from an input disc to an output disc in a transmission ratio (transmission gear ratio) corresponding to a tilt motion angle. The power roller allows the transmission ratio to be changed in such a manner that the position of the trunnion on which the power roller is tiltably supported is changed by a trunnion drive mechanism. Hydraulic oil is supplied from a hydraulic pump to the trunnion drive mechanism via a direction selector valve. The direction selector valve selects a flow direction of the hydraulic oil to supply the hydraulic oil to a speed reduction chamber or a speed increase chamber of the trunnion drive mechanism, and discharge the hydraulic oil from the other. In a case where a discharge condition is met, the controller controls a movement of the discharge valve to discharge the hydraulic oil from the speed increase chamber.

In a transmission device, a power roller transmits a rotational driving force from an input disc to an output disc in a transmission ratio (transmission gear ratio) corresponding to a tilt motion angle. The power roller allows the transmission ratio to be changed in such a manner that the position of the trunnion on which the power roller is tiltably supported is changed by a trunnion drive mechanism. Hydraulic oil is supplied from a hydraulic pump to the trunnion drive mechanism via a direction selector valve. The direction selector valve selects a flow direction of the hydraulic oil to supply the hydraulic oil to a speed reduction chamber or a speed increase chamber of the trunnion drive mechanism, and discharge the hydraulic oil from the other. In a case where a discharge condition is met, the controller controls a movement of the discharge valve to discharge the hydraulic oil from the speed increase chamber.

A variator comprises first and second races disposed for rotation about a variator axis and at least one rolling element disposed in a cavity between the races. In a drive configuration, drive is transmitted between the races and the at least one rolling element; and in a neutral configuration, the at least one rolling element and races are configured whereby the races can move independently of one another. In a method of operating the variator, the neutral configuration is obtained by moving the at least one rolling element to a position in which it ceases to make contact with at least one of the races. The drive configuration is obtained by moving the at least one rolling element to a position in which it makes contact with both of the races.

A variator comprises first and second races disposed for rotation about a variator axis and at least one rolling element disposed in a cavity between the races. In a drive configuration, drive is transmitted between the races and the at least one rolling element; and in a neutral configuration, the at least one rolling element and races are configured whereby the races can move independently of one another. In a method of operating the variator, the neutral configuration is obtained by moving the at least one rolling element to a position in which it ceases to make contact with at least one of the races. The drive configuration is obtained by moving the at least one rolling element to a position in which it makes contact with both of the races.

A position controller that performs position control by outputting a drive signal to a control valve of a hydraulic actuator that changes an operation position of an object, includes: a position acquisition unit that acquires an actual value of an operation position of the object; a position control unit that calculates an operation command value for the control valve by closed-loop control so as to reduce a deviation between a target value of the operation position of the object and the actual value; and a vibration wave application unit that applies a vibration wave to a signal of the closed-loop control so that the operation command value vibrates at a predetermined frequency at start of the closed-loop control.

A position controller includes: an oil temperature acquisition unit that acquires information on an oil temperature of a hydraulic actuator; a position acquisition unit that acquires an actual value of an operation position of an object; a position control unit that calculates an operation command value for a control valve of the hydraulic actuator by closed-loop control so as to reduce a deviation between a target value of the operation position of the object and the actual value; and a gain setting unit that changes at least one gain of the closed-loop control so that sensitivity of the closed-loop control increases as the oil temperature decreases.