Air motor proves a winner in caustic washdown application

02 September 2010

When US food packaging machine manufacturer, Greydon needed to modify a standard electric motor for caustic washdown it encountered some problems, not least among them being the prohibitive costs involved. An alternative approach was to find a low cost motor that not only met the demanding environmental specifications but also provided a relatively high degree of electronics-free precision and control capability.

Greydon’s Bagaire taped bag loader needed this level of precision to ensure efficient bag opening and filling as well as code-dating with inkjet or contact printers. The machine presents the bags by winding up a leader tape and pulling the bags up from a table. Shop air is used via an air amplifier to blow open the bag for manual filling by the operator who simultaneously breaks the bag away from the tape.

A Huco Dynatork piston air motor proved a good alternative to the electric unit. It is compact, so fits in a snug space under the machine, and as the bags need to be opened with a puff of air from the pneumatic system, the air motor offered a compatible approach.

In addition to its acetyl housing, which protects against caustic solutions and chlorinated sanitising agents, the Huco Dynatork air motor offers high torque at variable low speed. And as it traps compressed air within the piston/cylinder arrangement, maximum energy conversion is assured. The motor is also much easier to seal than its vane counterpart, so it consumes up to 80% less air, providing significant cost savings even at maximum torque.

Piston air motors excel in constant start-stop applications under load, and have similar characteristics to those of a stepper motor. An electric motor, on the other hand, will often burn out and a vane motor will stall when subjected to these conditions.

Huco Dynatork air motors are available with a maximum torque rating of 16Nm, but this can be increased to 550Nm with a suitable gearbox.