Sterilisable electromotors

Maxon Motor has extended its range of drive units with three sterilisable motors that can reach speeds of up to 100,000 rpm. The motors, now available for medical applications, are much quieter than compressed air turbines and the electric cables make them more flexible.

Three electronically commutated DC motors with diameters of 6, 16 and 22 mm that can be sterilised in an autoclave are available. The motors have to withstand saturated water vapour of 134°C at 2.3 bar repeated for at least 20 mins. In the past, only sensorless motors were robust enough to cope with the extreme loads in an autoclave, but the addition of Hall sensors to motors means that sterilisable highly dynamic servodrives are now possible.

A grooveless stator can be used through the use of a special winding that makes operation in a very wide speed range quiet and detent free.

The winding design helps produce high-speeds with relatively low voltages.