The She-N module is representative of a widely used, simple design principle: the angle of rotation is influenced by a stop directly on the rack (turning in/out). As with most manufacturers, the rotating output to the application is simply designed as a shaft. This design is low and cost-effective, but physics plays a role in a few places:

For a rotary movement, there must be play in the drive - so with this approach, the gearbox determines the repeat accuracy of the end position. As the stops act directly on the rack, the gearing is directly and constantly exposed to the impulse load. Both together influence each other in terms of technical data and durability.

With higher loads, there is a corresponding need for space for shock absorbers on the opposite side. Alternatively, the dampers can be found in the interior of rotary actuators. Alternatively, if the rotation limit is determined solely by the damper, the reproducibility of the end positions depends on a moving system and its properties (damper characteristics, effective stroke, ageing, temperature).

With internal stops, the final angular degrees before the end position are only approached with the force of a drive piston (in the direction of the stop screw). Despite a double-loaded unit, only around half of the nominal torque is available in the end position in systems with internal stops. Finally, due to the cost-effective positioning of the stop screws in the pressure chamber, adjusting or changing them is time-consuming - depressurization is required.

The result was a revised version of the She-A design with an external stop. The above disadvantages are compensated for by external stops, which the customer can reach from the outside for adjustment. With an external stop, the mechanical impulse load is shifted away from the gearbox and the repeat accuracy is improved. In addition, an external stop also provides the full torque in the end positions.

In the latest series of Wagner swivel units, the mounting of the stop screws is an integral part of the housing, which is milled from high-strength aluminum. Two pivoted stop blocks, together with the stop screws, provide a swivel range that can be fully adjusted from the outside with a ring-shaped stop. The fine thread of the stop screw and subsequent countering enable precise adjustment for high repeat accuracy. The external stop provides full torque in the end positions, relieves the drive and decouples the accuracy from the gearbox, which has a positive effect on service life and precision. Thanks to the patented stop system (the inductive initiator is located in the hollow stop screw), all stop masses now point in one direction.

The special sensor, especially its position directly at the end position, enables shock absorber failure to be detected and can protect against consequential damage and downtime. The usual "output shaft" is designed ex works as a stop surface. It is used for direct mounting of the superstructure using a grid dimension and centering system. At the same time, it provides space for air and signal feed-throughs and enables structure and simple installation. as