Rotary positioning and measuring to sub-micron accuracy

Heidenhain has released two modules, the SRP5080 and SRP 5010, that include a torque motor, a precision bearing and a high resolution angle encoder to make building CNC machines quicker and easier.

The SRP 5080 is fitted with an incremental encoder and the SRP 5010 an absolute encoder. Both can provide an all-in-one system for controlling rotary and tilting motions to within 2.5s of arc and feeding the position back to a CNC system. Typical applications are on 4- and 5-axis machine tools, metrology stations, articulated joints and other equipment where smooth and precise rotary positioning is required. The modules represent an alternative to air bearing axes, especially as the motor has low detent torque so there is no discernible cogging.

Heidenhain manufactures the roller bearing and the encoder, making them highly compatible; they also require fewer components than conventional solutions and have a rigid, low profile design. Available with a 35 or 100mm diameter hollow shaft, the modules are said to reduce installation and calibration times, as matching the individual components to each other as well as to the machine environment is not necessary, nor is time-consuming testing.

With an axial load capacity of 200N, the modules feature low and consistent frictional torque below 0.2Nm, promoting smooth motion at up to 3000rpm. Axial guideway accuracy of the bearing is claimed to be better than ±0.02µm, while in the radial direction 0.02µm accuracy is exceeded, even under changing loads and operating temperatures from 0 to 50°C.