Design of a High speed high performance linear axis
In the Figure above a linear motion axis is shown equipped with an ironless linear motor and aerostatic bearings preloaded by magnets. The slide surface is made of structural steel coated with a hard chromium layer and finally grinded. The circular thrust bearings of 40mm diameter are designed to carry a load up to 500N each when fed with a supply pressure of 5 bars. The nominal film thickness amounts 5Ám. The moving mass of the rotor is 2.9 kg. With the peak force of the linear motor of 470 N the rotor accelerates with 160 m/s2. A linear encoder is used for accurate positioning of the rotor within tenths of a micrometer.

Newly design partially grooved air bearings are applied. Compared to the shallow pocket bearing this bearing shows improved load capacity and self aligning capacity.