A device is disclosed that performs highly accurate control in a low-torque region and improves the response of the hydraulic system, taking advantage of hydraulic sealed-type hydraulic control devices. The hydraulic sealed-type hydraulic control device includes: a first characteristic (sealed pressurization) obtained by closing an on-off valve and driving an oil pump; a second characteristic (sealed depressurization) obtained by disabling drive of the oil pump and opening the on-off valve; and a third characteristic (flow-rate control) obtained by opening the on-off valve and driving the oil pump. In a low-torque region, the device performs control according to the third characteristic. In a high-torque region, the device performs control according to the second characteristic. In the process of depressurization, the device performs control according to the second characteristic. Moreover, the device performs control to increase commanded hydraulic pressure in immediate response to an accelerator's change amount larger than a predetermined value.

A device is disclosed that performs highly accurate control in a low-torque region and improves the response of the hydraulic system, taking advantage of hydraulic sealed-type hydraulic control devices. The hydraulic sealed-type hydraulic control device includes: a first characteristic (sealed pressurization) obtained by closing an on-off valve and driving an oil pump; a second characteristic (sealed depressurization) obtained by disabling drive of the oil pump and opening the on-off valve; and a third characteristic (flow-rate control) obtained by opening the on-off valve and driving the oil pump. In a low-torque region, the device performs control according to the third characteristic. In a high-torque region, the device performs control according to the second characteristic. In the process of depressurization, the device performs control according to the second characteristic. Moreover, the device performs control to increase commanded hydraulic pressure in immediate response to an accelerator's change amount larger than a predetermined value.

A differential gear unit includes an annular ring gear having a rotational axis in an axial direction; side gears respectively distribute torque to drive shafts; differential pinion gears are rotatably arranged on a pinion pin, where the pinion gears respectively engage the side gears. A decoupling element inside the ring gear is rotatably arranged in relation to the ring gear. The pinion pin is connected to and extends diametrically across the decoupling element. A clutch sleeve slides relative to the ring gear and the decoupling element. The clutch sleeve, upon axial displacement, disconnects the ring gear from the decoupling element in a first position, allowing rotational movement of the decoupling element relative to the ring gear; connects the ring gear to the decoupling element in a second position, preventing the rotational movement of the decoupling element; and connects the ring gear to a park-lock structure in a third position.

A disconnector apparatus with a limited slip differential function includes a casing, first and second pressure rings provided at two opposite sides while opposing each other at an interval in the casing and having first dog portions provided on outer-diameter portions thereof, and a clutch ring coupled to an outer-diameter portion of the casing and connected to a sleeve configured to be operated by an operation of an actuator device, in which the clutch ring moves in a meshing direction when the sleeve is operated by the actuator device, such that second dog portions provided on an inner-diameter portion of one end positioned in the casing mesh with first dog portions of the first and second pressure rings, such that four-wheel drive is implemented.