Abstract: An actuator unit including a step-up which varies over an adjustment path, between a control motor and a wheel connected to the throttle body in a manner fixed against relative rotation offers the advantage that in certain positions of the throttle body, the required increased torque can also be brought to bear by a relatively low-torque control motor. The actuator unit is intended in particular for internal combustion engines for motor vehicles.

Abstract: A flap valve for controlling a gas flow has an elastically deformable valve tube that conveys the gas flow and having a valve flap that is disposed in the valve tube for movement between an open position and a closed position by a flap shaft that can be driven in order to adjust the valve flap and which is disposed at an acute angle in relation to the valve tube axis, to which shaft the valve flap is fastened so that in the closed position of the valve flap, the flap normal encloses an acute angle with the valve tube axis, in order to assure only a slight amount of leakage in the closed position of the valve flap and a low opening torque, the outer contour of the valve flap is approximately oval in shape. Preferably, the outer contour is embodied as an ellipse.

Abstract: In actuator units known until now, there is a constant step-up between the control motor and the throttle body. The control motor must be designed such that the torque of the control motor suffices in every position of the throttle body.

Abstract: In a flap valve for controlling a gas flow, having an elastically deformable valve tube (11) that conveys the gas flow and having a valve flap (12) that is disposed in the valve tube (11) and can be moved between an open position and a closed position, and having a flap shaft (13) that can be driven in order to adjust the valve flap (12) and is disposed at an acute angle (&agr;) in relation to the valve tube axis (111), to which shaft the valve flap (12) is fastened so that in the closed position of the valve flap (12), the flap normal (nK) encloses an acute angle with the valve tube axis (111), in order to assure only a slight amount of leakage in the closed position of the valve flap (12) and a low opening torque, the outer contour of the valve flap (12) is approximately oval in shape. Preferably, the outer contour is embodied as an ellipse (FIG. 1).