The present invention relates to a technology in which a transition between a medium-torque transmission state and a high-torque transmission state by a limited slip differential is continuously performed during a driving process of a vehicle. The present invention introduces a limited slip differential configured to comprise: an input shaft constantly connected to a differential case of a slip differential; an output shaft selectively connected to the input shaft via a clutch pack and constantly connected to a wheel; a medium-torque transmission means for pressing a clutch plate coupled to the input shaft to press-fit the clutch pack; and a high-torque transmission means selectively engaged with the clutch plate by moving a hub coupled to the output shaft in a state where the input shaft and the output shaft are synchronized as the clutch pack is fastened, and a controlling method therefor.

A transfer case having a lubrication guide with an inlet, an outlet and an elongated tubular portion that is disposed between the inlet and the outlet. The lubrication guide is coupled to a drive assembly that transmits rotary power between a pair of output shafts such that the inlet is disposed proximate a first rotary component of the drive assembly to receive splash lubrication (i.e., slung lubrication and/or surge lubrication) therefrom.

A transfer includes: an input shaft; an output shaft; a high-low switching mechanism; an output member whose output destination is different from output destination of the output shaft; a clutch for transmitting a power to the output member; a first transmitting mechanism for transmitting movement of an internally threaded member to the clutch; and a drum cam having a cam groove. The cam groove includes a first inclined section that causes the high-low switching mechanism to be switched between a high-speed gear stage and a low-speed gear stage, and a second inclined section that causes the first transmitting mechanism to be switched between (i) a separated position in which the first transmitting mechanism is separated from the clutch and (ii) a contact position in which the first transmitting mechanism is in contact with the clutch, while the high-speed gear stage is established in the high-low switching mechanism.

A transfer device of a vehicle is provided, which includes an input shaft for receiving an output torque of a drive source at an axial first side, a main-wheel output part provided on a second side and for outputting the output torque to main drive wheels, an auxiliary-wheel output shaft provided in parallel to the input shaft and for outputting the output torque to auxiliary drive wheels, a coupling provided on the input shaft and for extracting a part of the output torque, a drive member having a hollow section and provided on the input shaft, a driven member provided on the auxiliary-wheel output shaft and meshed with the drive member, a universal joint provided on the auxiliary-wheel output shaft, and a damper device provided on the input shaft or the auxiliary-wheel output shaft and for reducing noise that occurs due to a variation of the output torque.

A lubrication system (400) for a transfer case (200) includes a pump (228) selectively supplying a working fluid to a fluid reservoir of an actuator (226) configured to apply force to a clutch assembly (214) to cause the clutch assembly (214) to move between a disengaged position and an engaged position. The lubrication system also includes a relief valve (302) having a relief valve inlet fluidly coupled to the fluid reservoir of the actuator (226) which opens to receive the working fluid based on a threshold pressure level of the working fluid in the fluid reservoir. The lubrication system also includes a trough (306) fluidly coupled to a relief valve outlet of the relief valve (302). The trough (306) carries the working fluid from the relief valve outlet to a bearing assembly (227) associated with at least one of an input shaft (204) and a primary output shaft (206) of the transfer case (200) when the clutch assembly (214) is in the disengaged position.

A vehicle transfer structure includes a main-drive-wheel output shaft that receives torque from a drive source and outputs it to main drive wheels, a part-time-drive-wheel output shaft provided parallel to the main-drive-wheel output shaft, a coupling provided on the main-drive-wheel output shaft and which partially extracts the torque to the part-time-drive-wheel output shaft via a transmission mechanism, and a damper disposed on the main-drive-wheel output shaft. The coupling is provided with an input-side coupling part coupled to an inner circumferential part of the damper. The input-side coupling part is coupled, via a spline-fitted section, to an output-side coupling part of a drive force transmission member which is coupled to an outer circumferential part of the damper and transmits a drive force to a driving-side transmission member of the transmission mechanism. The spline-fitted section allows a relative rotation between the input- and output-side coupling parts within a given angle.

A control apparatus that controls a four-wheel drive vehicle in which a driving force is transmitted to rear wheels via a dog clutch, a propeller shaft, and a driving force transmission apparatus is configured to, when switching to a four-wheel drive mode, reduce a difference in rotation speeds of an intermediate rotational member and a ring gear member by a frictional force between a friction surface of a friction member, which is configured such that its rotation relative to the intermediate rotational member is restricted, and a target frictional slide surface of the ring gear member, and then couple the intermediate rotational member and the ring gear member by a clutch member in a state in which engagement forces of friction clutches configured to transmit the driving force between each of first and second output rotational members and the intermediate rotational member of the driving force transmission apparatus are set to engagement forces that allow their relative rotation.

A drive force control device, which controls a drive force distribution device that distributes a drive force to right and left rear wheels at variable distribution ratios, computes a steering angle-based turning radius determined in accordance with a steering angle, computes a limit turning radius, which is a minimum value of the turning radius with which the vehicle is turnable while keeping a stable travel state, in accordance with a vehicle speed, sets the larger one of the steering angle-based turning radius and the limit turning radius as a target turning radius, computes target rotational speeds for the right and left rear wheels on the basis of the target turning radius and the vehicle speed, and adjusts the ratios of distribution of the drive force to the right and left rear wheels such that actual rotational speeds of the right and left rear wheels approximate the target rotational speeds.

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.