Vacuum applications

Tecnotion vacuum rated ironless linear motors are optimized in various ways to perform in very strict vacuum conditions to prevent unwanted chemical reactions, contaminations or influences due to magnetic stray fields on the process. Improvements are realized in the areas of outgassing, heat extraction and force generation.

Outgassing and virtual leaks

Outgassing is a process in which gas that has been dissolved, absorbed, or trapped is released through the process of sublimation, evaporation, desorption, or seepage. In a vacuum environment, the gas is released into the vacuum. This means that the effective pumping speed must be increased to maintain a certain vacuum level as the outgassing increases.

Materials found in the coil units and magnet yokes/tracks of direct drive motors, such as the resin, magnet adhesive, and cable jacket have relatively high outgassing values. Tecnotion vacuum motors are enclosed with a material that has greatly reduced outgassing values, making them suitable for vacuum environments. Because the motors are wholly or partially sealed with a stainless steel or aluminum jacket and the enclosed magnets are coated with a nickel alloy, this prevents the trapped gas from leaving and entering the vacuum.

A virtual leak is a gas source that is trapped but is able to gradually escape from its pocket as the pressure in the environment decreases. One of the most common examples of a virtual leak is the gas that is trapped in a blind tapped hole with a screw inserted. Virtual leaks cause a higher gas load that must be pumped out to reach a certain vacuum level. At a higher gas load, a higher effective pump speed is needed to reach the desired vacuum level. Tecnotion vacuum-rated motors are designed with attention to minimizing virtual leaks.