Abstract: A continuously variable transmission for an automotive vehicle, including a power train whose speed ratio is variably changeable in accordance with an oil pressure signal from a control valve assembly. A mechanical feedback mechanism is provided including an actuator for speed-change control operable in accordance with an electric signal. The actuator has a solenoid section. A speed-change control valve is provided to control an oil pressure to be supplied to the power train. A speed ratio sensor is provided to be moved in mechanical relation to a part of the power train in accordance with a change in the speed ratio of the power train. A linking member is provided to link the actuator, the speed-change control valve and the speed ratio sensor. Additionally, an oil bath is provided to contain oil in which at least a part of the solenoid section of the actuator is immersed.

Abstract: Hydraulic control system and method for an automatic transmission. The hydraulic control system includes a hydraulic pressure source, a flow rate control valve having a spool with an orifice and a drain hole, stroke position determining means, and pressure regulator means. The stroke position determining means determines that the spool is displaced from a large spool-stroke position where a communication area of the drain hole is not less than a first predetermined area, to a small spool-stroke position where the communication area is not more than a second predetermined area. The pressure regulator means regulates a hydraulic oil pressure downstream of the orifice and corrects the hydraulic oil pressure downstream of the orifice by adding a predetermined correction amount for a first predetermined time when the stroke position determining means determines that the spool is displaced from the large stroke position to the small stroke position.

Abstract: A continuously variable transmission for an automotive vehicle, including a power train whose speed ratio is variably changeable in accordance with an oil pressure signal from a control valve assembly. A mechanical feedback mechanism is provided including an actuator for speed-change control operable in accordance with an electric signal. The actuator has a solenoid section. A speed-change control valve is provided to control an oil pressure to be supplied to the power train. A speed ratio sensor is provided to be moved in mechanical relation to a part of the power train in accordance with a change in the speed ratio of the power train. A linking member is provided to link the actuator, the speed-change control valve and the speed ratio sensor. Additionally, an oil bath is provided to contain oil in which at least a part of the solenoid section of the actuator is immersed.

Abstract: In a continuously-variable transmission, a powertrain is arranged to continuously vary a transmission ratio. An upper body of a control valve unit is disposed at a surface of the control valve unit confronting the powertrain. A lower body of the control valve unit is connected to the upper body. A shift control actuator is arranged to operate in accordance with an electrical signal. A shift control valve is arranged to perform a hydraulic control for the powertrain. A transmission ratio detecting section is arranged to operate mechanically in accordance with variation of the transmission ratio. A link member is disposed adjacent to the upper body and inside a plane of projection of the surface confronting the powertrain, and links the shift control actuator, the shift control valve and the transmission ratio detecting section.

Abstract: Hydraulic control system and method for an automatic transmission. The hydraulic control system includes a hydraulic pressure source, a flow rate control valve having a spool with an orifice and a drain hole, stroke position determining means, and pressure regulator means. The stroke position determining means determines that the spool is displaced from a large spool-stroke position where a communication area of the drain hole is not less than a first predetermined area, to a small spool-stroke position where the communication area is not more than a second predetermined area. The pressure regulator means regulates a hydraulic oil pressure downstream of the orifice and corrects the hydraulic oil pressure downstream of the orifice by adding a predetermined correction amount for a first predetermined time when the stroke position determining means determines that the spool is displaced from the large stroke position to the small stroke position.