A four-wheel drive vehicle comprises: a dog clutch; an electronically controlled coupling; and a control device switching a drive state to the four-wheel drive state when the control device determines that a running road surface is a low friction road and switching the drive state to the two-wheel drive state when the control device determines that the running road surface is a high friction road. In the case of switching the drive state from the four-wheel drive state to the two-wheel drive state, the control device temporarily releases the electronically controlled coupling to redetermine whether the running road surface is the low friction road or the high friction road before releasing the dog clutch and prohibits switching from the four-wheel drive state to the two-wheel drive state when it is redetermined that the running road surface is the low friction road.

A driving force distribution control system for a four-wheel drive vehicle is provided. The four-wheel drive vehicle uses front wheels as main driving wheels, and when a towed vehicle is coupled to a coupling part provided to a rear part of the four-wheel drive vehicle, the towed vehicle has the center of gravity position so that a downward load in a vehicle up-and-down direction is applied to the rear part of the vehicle through the coupling part. A driving force distribution control device includes a towing determination module configured to determine whether the vehicle is towing the towed vehicle, and when it is determined that the vehicle is towing the towed vehicle, a driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to rear wheels becomes larger than that when the four-wheel drive vehicle is not towing the towed vehicle.

A driving force distribution control system for a four-wheel drive vehicle is provided. The four-wheel drive vehicle uses front wheels as main driving wheels, and when a towed vehicle is coupled to a coupling part provided to a rear part of the four-wheel drive vehicle, the towed vehicle has the center of gravity position so that a downward load in a vehicle up-and-down direction is applied to the rear part of the vehicle through the coupling part. A driving force distribution control device includes a towing determination module configured to determine whether the vehicle is towing the towed vehicle, and when it is determined that the vehicle is towing the towed vehicle, a driving force distribution control device controls the driving force distributing device so that the driving force distributing amount to rear wheels becomes larger than that when the four-wheel drive vehicle is not towing the towed vehicle.

A drive train unit for a motor vehicle includes a housing and an input shaft rotatably mounted in the housing and arranged for attachment to an output of a transmission in a rotationally fixed manner. The input shaft has a first input shaft section and a second input shaft section that can move axially in relation to the first input shaft section. The drive train unit may include an electric machine arranged parallel to the input shaft, and a first clutch. The electric machine has a rotor and the first clutch arranged to connect the rotor and the input shaft for torque transmission in a shift position. The drive train may include an output shaft rotatably mounted in the housing and arranged for rotational coupling to a distributer transmission, and a second clutch arranged to connect the input shaft and the output shaft for torque transmission in a shift position.

A drivetrain unit for a motor vehicle comprises a hybrid module, which includes an electric machine having a stator and a rotor, with at least two clutches having clutch parts that are respectively connectable to one another. A rotor carrier is provided, to which the rotor is attached and to which in each case one clutch part of the at least two clutches is connected for conjoint rotation therewith. A transmission device interacts with the hybrid module by a first transmission input shaft and the rotor carrier is mounted on the first transmission input shaft so as to be rotatable relative thereto.

Fluid control apparatus for use with vehicle clutches are disclosed. A disclosed clutch coupling assembly for a vehicle includes a housing defining a cavity. The clutch coupling assembly also includes a fluid reservoir fluidly coupled to the cavity. The clutch coupling assembly also includes a clutch positioned in the cavity. Rotation of the clutch is to convey a fluid from the cavity to the fluid reservoir. The clutch coupling assembly also includes a pump operatively coupled to the housing to control the fluid. Operation of the pump is to convey the fluid from the fluid reservoir to the cavity when the clutch is in an engaged state.

Piston apparatus for use with vehicle clutches are disclosed. A disclosed drive unit assembly for a vehicle includes a housing defining a first cavity and a second cavity fluidly coupled together. The drive unit assembly also includes a clutch positioned in the first cavity. Rotation of the clutch conveys a fluid from the first cavity to the second cavity. The drive unit assembly also includes a port extending from the second cavity to the first cavity to receive the fluid. The drive unit assembly also includes a piston positioned in the first cavity proximate to the port and configured to operate the clutch. Movement of the piston relative to the port controls a flow of the fluid through the port from the second cavity to the first cavity.

A clutch device includes a first input side and a second input side, a first output side and a second output side, a first clutch arranged between the first input side and the first output side, a second clutch arranged between the first input side and the second output side, and a third clutch arranged between the first input side and the second input side. The first input side is couplable to a first drive motor and the second input side is couplable to a second drive motor, the input sides and the output sides are rotatable about a common axis of rotation, and the third clutch is arranged offset from the first clutch or the second clutch. In an example embodiment, the third clutch is arranged radially offset with respect to the first clutch or the second clutch.

In a hydraulic clutch actuation system for controlling in particular a clutch-controlled compensation unit of a drivetrain of a motor vehicle, in which hydraulic clutch actuation system a hydraulic pump is used for generating hydraulic pressure in a hydraulic fluid for the purposes of clutch actuation by means of a hydraulic clutch actuation device, provision is made whereby the hydraulic fluid is supplied as clutch oil to the friction members of the friction clutch which are to be oiled with clutch oil (cooling and/or lubricating oil). In this way, improved and more reliable oiling of the clutch can be made possible even at low vehicle speeds and under heavy clutch load, wherein, despite this, very rapid dry-running of the cutches, and low power losses generated by the clutch oiling, are ensured.

A wet-type multi plate clutch is configured to be used for a transmission in an automobile. A clutch pack is provided with a plurality of drive plates and a plurality of driven plates. The drive plates have single surfaces on which first clutch facings are fixed and opposed surfaces on which annular grooves are formed along entire peripheral lengths. The driven plates have single surfaces on which second clutch facings are fixed and opposed surfaces on which annular grooves are formed along entire peripheral lengths. The sliding surfaces of the drive plates and the driven plates are arranged between the first and second clutch facings, which are axially adjacent with each other.