Air motors have precision bagged

To complete its design of a system to bag-up meat and cheese and apply appropriate label information US pack-aging machine manufacturer, Greydon, encountered obstacles. The cost of modifying a standard electric motor to suit the machine's intended 100% caustic washdown environment had proved cost-prohibitive. And in any event, such an environment is much better suited to a solution involving minimum electronic components.  

So the hunt was on to find a low cost motor meeting these credentials but with a relatively high degree of precision and control. These qualities were needed by the Greydon Bagaire Taped Bag Loader not only for efficient bag opening and filling but also for code-dating with inkjet or contact printers. 

"The Huco Dynatork piston air motor was a good find for us," explains Brian Newman of Greydon. "It is compact, fitting in a snug space under the machine. And as the bags are opened with a puff of air from the pneumatic system, an air motor was the ideal solution."

The machine presents the bags by winding up a leader tape and pulling the bags up from the 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.  

The Huco Dynatork motor advances the bags quickly and stops them precisely in exactly the same location for opening and printing. As it is available with an acetyl housing, this motor is able to withstand the most caustic acids and chlorinated sanitizers used in the food and pharmaceutical industries.

The operating principle of the Huco Dynatork air motor is simple. Via an integral rotary valve, air up to 100 psi is supplied to each of three pistons in turn. The free-floating pistons transmit torque on start-up that can be adjusted via a pressure regulator.

This results in high torque at variable low speed and also low noise.  As the air motor traps the compressed air within the piston/cylinder maximum energy conversion is assured. Also the motor is much easier to seal than its vane counterpart. As a result the Huco Dynatork motor consumes up to 80% less air than a vane motor, providing significant cost savings even at maximum torque.

David Lockett, managing director of Huco Dynatork explains that the motor excels in constant start-stop applications under load, displaying similar characteristics to those of a stepper motor. He says: "By comparison, an electric motor will often burn out and a vane motor will stall when subjected to these conditions." Air motors provide an effective, reliable and affordable option in demanding washdown environments. The alternative of a stainless steel sealed electric motor is more expensive, the gearbox assembly often too heavy, and a specially designed inverter panel or enclosure often too cumbersome. 

Air motors from Huco Dynatork combine precise positioning and efficient operation with the ability to withstand the rigours of even 100% caustic washdown environments. As standard, the motors are able to operate totally immersed in water, so even high pressure wash downs are not a problem. And with acetal housings also available, the motors are able to withstand most caustic acids and chlorinated sanitizers used in the food industry.

Huco Dynatork air motors are available with maximum torque rates of up to 16Nm or up to 550Nm with a gearbox.