Electromagnetic actuator

The linear solenoid from RAPA Automotive is one of the electromagnetic actuators in the Powertrain product range. It is a linear force actuator that can be used for various applications. Depending on the objective, these are customer-specific special solutions.

The actuator, which has been available on the market since 2015, is used in automatic transmissions. If the vehicle's parking lock is engaged hydraulically, the solenoid is responsible for engaging the parking lock, i.e. securing the position of the parking lock.

As the actuator is installed inside the transmission, it has a small size, a screw flange mounting and a specific electrical plug-in connection. The actuator delivers forces of up to 25 Newtons over a stroke of 2.2 mm.

The electromagnetic linear actuator from RAPA Automotive is used in an active engine mount. In contrast to conventional engine mounts, the actuator is controlled dynamically to enable frequency-selective adjustment of the bearing stiffness. This is an enormous gain in comfort, especially for vehicles with cylinder deactivation and hybrid drives.

The operational vibrations of an internal combustion engine cause a change in pressure in the working chamber of the active engine mount. Through its linear movement, the actuator actuates a diaphragm, which also leads to a pressure change in the working chamber. The control is carried out in such a way that the resulting pressure change in the working chamber is minimized. This reduces the force applied to the body via the engine mount attachment points, which leads to a noticeable and audible reduction in excitation in the vehicle.

The actuator is characterized by a frictionless armature bearing. This is realized by means of two so-called S-springs and enables high dynamics.