Such devices can be used, for example, in the form of so-called disconnect systems to decouple parts of the drive train in a motor vehicle with selectable all-wheel drive so that in two-wheel drive, the connection between the primary axle or drive unit on one side and the secondary axle on the other can be at least partly separated. In order thus to prevent the associated movement of parts of the drive train not required in permanent two-wheel drive mode, in particular unnecessary masses, by releasing the clutch the torque transfer segment leading to the secondary axle can be interrupted.
Alternatively, coupling arrangements of said type can also be used in a vehicle with hybrid drive during electric operating mode to separate the main transmission from the combustion engine in order thus to prevent power losses and minimize noise. A drive train decoupling for an electric drive can also be provided on the secondary axle. In the known systems, the clutches are activated i.e. opened or closed either by means of a hydraulic or pneumatic actuator or by means of an electric motor. In general the torque transmission can take place from the rotating shaft as input element to said drive element of the drive train as output element, or in the opposite direction.
A coupling arrangement of the generic type is disclosed in DE 10 2009 049 013 A1. In this system, an electric motor is provided to move a clutch switch element in the opening direction, while the movement of the switch element in the closing direction is achieved by a spring element.
In the known applications the aim is to engage the clutch based on the principle of form-fit engagement, for example, a claw-type clutch, with relatively high speed. This can, however, lead to shocks, vibrations and noise in the drive train, which are perceived as unpleasant by the driver of the vehicle.
USPTO Backgrounds
USPTO Backgrounds