Why Doesn RUF Use Linear Motors?
The concept of linear motors is fascinating. We are used to rotary electric motors where magnetic poles are pulled by magnetic fields in order to make the rotor rotate. Suddenly somebody gets the idea of straighten out the rotor and let it glide along an array of magnetic poles. This concept can be used to make linear movements and is widely used within the industry. It seems natural to use the principle in a system where vehicles are moving along a line. What is the problem? Efficiency The efficiency of an electric motor is very much dependent on the air gap between rotor and stator. The smaller the air gap the better. With good bearings it is relatively easy to obtain a very small air gap in a rotary electric motor. In a LIM/LSM motor, the air gap needs to be larger for different reasons: There is some kind of wheel involved in order to maintain the air gap between stator (guideway) and “rotor” (electromagnetic array). This wheel has bearings with some tolerance, but more important,
