Abstract: A motor vehicle with insertable four-wheel drive, including an engine having a crankshaft, a pair of main driving wheels constantly connected to the crankshaft by interposition of a gearbox provided with a first clutch, and a pair of secondary driving wheels, which may be connected to the crankshaft by an insertable transmission system. The insertable transmission system presents a second clutch, which is connected on one end with a fixed transmission ratio to the crankshaft upstream of the gearbox and on the other end with a fixed transmission ratio to the secondary driving wheels. A percentage of motive torque to be transmitted to the secondary driving wheels by the second clutch is determined according to dynamic parameters of the motor vehicle detected by respective sensors.

Abstract: An optionally connectable four-wheel drive vehicle having: an engine having a drive shaft; two main drive wheels; a main power train permanently connecting the drive shaft to the main drive wheels and, in turn, having a transmission and a main differential; two normally driven secondary drive wheels; an optionally connectable secondary power train for also connecting the drive shaft to the secondary drive wheels, a gear drive with at least two different, alternatively selectable velocity ratios, and at least one secondary clutch, which is connected on one side to the drive shaft upstream from the transmission and on the other side to the secondary drive wheels.

Abstract: An integrated clutch-transmission assembly for a road vehicle; the integrated clutch-transmission assembly has a power-assisted clutch having a number of first hydraulic actuators; a power-assisted transmission having a number of second hydraulic actuators; a high-pressure pump for the hydraulic actuators; a number of solenoid valves for controlling the hydraulic actuators; a housing having a first chamber housing the clutch, and a second chamber housing the transmission; and a flat supporting plate, which is housed removably inside the housing to separate the two chambers of the housing, has a first wall fitted with the clutch, and has a second wall parallel to and opposite the first wall and fitted with the high-pressure pump and at least some of the solenoid valves.

Abstract: A motor vehicle with insertable four-wheel drive, including an engine having a crankshaft, a pair of main driving wheels constantly connected to the crankshaft by interposition of a gearbox provided with a first clutch, and a pair of secondary driving wheels, which may be connected to the crankshaft by an insertable transmission system. The insertable transmission system presents a second clutch, which is connected on one end with a fixed transmission ratio to the crankshaft upstream of the gearbox and on the other end with a fixed transmission ratio to the secondary driving wheels. A percentage of motive torque to be transmitted to the secondary driving wheels by the second clutch is determined according to dynamic parameters of the motor vehicle detected by respective sensors.

Abstract: An optionally connectable four-wheel drive vehicle having: an engine having a drive shaft; two main drive wheels; a main power train permanently connecting the drive shaft to the main drive wheels and, in turn, having a transmission and a main differential; two normally driven secondary drive wheels; an optionally connectable secondary power train for also connecting the drive shaft to the secondary drive wheels, a gear drive with at least two different, alternatively selectable velocity ratios, and at least one secondary clutch, which is connected on one side to the drive shaft upstream from the transmission and on the other side to the secondary drive wheels.

Abstract: A connectable four-wheel drive vehicle includes an engine having a gear shaft; two main drive wheels connected permanently to the drive shaft by interposition of a gearbox having a first clutch; and two secondary drive wheels selectively connectable to the drive shaft by a connectable drive system. The connectable drive system includes a second clutch which, on one side, is connected with a fixed velocity ratio to the drive shaft upstream from the gearbox, and on another side, is connected with a fixed velocity ratio to the secondary drive wheels.

Abstract: An integrated clutch-transmission assembly for a road vehicle; the integrated clutch-transmission assembly has a power-assisted clutch having a number of first hydraulic actuators; a power-assisted transmission having a number of second hydraulic actuators; a high-pressure pump for the hydraulic actuators; a number of solenoid valves for controlling the hydraulic actuators; a housing having a first chamber housing the clutch, and a second chamber housing the transmission; and a flat supporting plate, which is housed removably inside the housing to separate the two chambers of the housing, has a first wall fitted with the clutch, and has a second wall parallel to and opposite the first wall and fitted with the high-pressure pump and at least some of the solenoid valves.

Abstract: A connectable four-wheel drive vehicle includes an engine having a gear shaft; two main drive wheels connected permanently to the drive shaft by interposition of a gearbox having a first clutch; and two secondary drive wheels selectively connectable to the drive shaft by a connectable drive system. The connectable drive system includes a second clutch which, on one side, is connected with a fixed velocity ratio to the drive shaft upstream from the gearbox, and on another side, is connected with a fixed velocity ratio to the secondary drive wheels.

Abstract: The invention relates to a viscous coupling such as it used in the driveline of a motor vehicle, wherein, due to a relative rotational movement between the inner plates 80 and the outer plates 90, the viscous medium is made to flow towards the axis of rotation X--X of the viscous coupling. To achieve this objective, the plates 80, 90 are provided with closed apertures 81, 91, whose delimiting faces 82, 83, 92, 93 are inclined relative to an imaginary radius R, so that, in the case of a rotational movement, the delimiting faces press the viscous medium inwardly, independently of the direction of rotation. This counter-acts a separation of viscous medium and air often caused by centrifugal forces at high speeds. As a result, the plates 80, 90 are moistened uniformly, which, in turn, reduces the amount of wear and increases the service life of the viscous coupling.