Submersible and Non-Magnetic Air Motors

Whilst it’s not impossible to render an electric or hydraulic motor suitable for complete submersion in water it is costly, complicated and time-consuming. Nevertheless in the marine engineering and process industries there is a real need for such drives and for these applications Huco Dynatork now has the complete answer.

Building on the inherent benefits of its basic air motor design that was specifically designed for operation in harsh and hazardous environments, the company has developed a fully submersible range. These acetyl bodied models with stainless steel shafts and bearings are available in two sizes and specials can be made to order. Ideal for any motion control application underwater such as opening a valve or for propelling a stirring mechanism for example, the motor is also a good choice for washdown environments and flood-risk areas. The motor can withstand aggressive chemicals, high pressure hosing and can operate fully submerged. In common with the standard range, these new submersible motors excel in constant start/stop applications under load and can be applied to give similar characteristics to those of a stepper motor. Reverse operation is achieved by using 5-port control valves giving near instant response even under load.

All the Huco Dynatork submersible air motor needs to operate is compressed air and even that is minimal. It requires up to 80% less than vane motors, providing significant cost savings even at maximum torque. Free-floating pistons transmit maximum torque on start-up that can be adjusted via a pressure regulator.

As a ready supply of compressed air is common in the marine and offshore sites this new motor will of particular interest to these sectors. Air can be supplied via a reservoir and tests have confirmed that a Huco Dynatork motor will run continually for more than 15 minutes from a standard diving cylinder.

Another important air motor development that is already generating considerable interest in the nuclear industry is the new Huco Dynatork non-magnetic model. It combines stainless steel shafts and ceramic bearings enabling the motor to be used in a high magnetic field. It is ideal for applications involving particle acceleration and in systems such as MRI scanners.

A Flywheel coupling to suit every pump and engine

As result of changing from traditional vane motors to Huco Dynatork non-lubricated air motors for paint stirring, one UK automobile plant is saving in the region of $130,00 annual in power costs and plant renewals alone. 

The customer’s original purchasing criteria for the motors were greater reliability on 24/7 operation and freedom from lubrication to avoid the possibility of contamination. However the switch to the Huco Dynatork model did much more than meet these modest needs. It also substantially cut the need for shop air as even at maximum torque, this design requires less than a quarter of the air consumed by a traditional vane motor. 

This manufacturer has now installed 42 Huco Dynatork motors and these have provided a capital saving of two 600scfm compressors and an overall power saving of 152kVA annual. 

The operating principle of the Huco Dynatork air motor is simple and unique. Via an integral rotary valve, air up to 6.5 bar 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 low noise. 

The motor is ideal for use in harsh and hazardous environments and excels in constant start/stop applications under load displaying similar characteristics to those of a stepper motor. By comparison an electric motor will often burn out and a vane motor, stall out when subjected to these conditions. 

These qualities make the Huco Dynatork air motor the perfect choice for paint and other liquid stirring applications across a wide spectrum of industries.

Piston Air Motor Ideal for the Food Environment

The Huco Dynatork air motor is quite ingenious.  It is based on a unique free-floating piston design that is capable of precise position control.   Maximum torque is transmitted on start-up and this can be adjusted to fine limits by standard air-flow valves.  Unlike other makes that operate with a system of metal pistons and connecting rods, the Huco Dynatork motor is perfect for stop/start load speed applications under load.

Unlike its vane counterpart the Huco Dynatork air motor is also easier to seal.  It is therefore far more cost efficient as most of the energy stored up in the compressed air is converted into motion.  In fact it consumes up to 80% less air than a vane motor providing significant cost saving even at maximum torque.

This is an exceptionally clean motor available with non-lube air supply and in a corrosion resistant or acetyl housing.  It’s little wonder then that this economical and efficient product has attracted designers of food preparation and packaging systems.  However, it has to be said that until now its commercial potential has been somewhat impeded. 

When Huco acquired Dynatork, the company inherited a product that was highly effective but remained a first generation design.  It had some design issues that hindered its take-up in the hygiene conscious sectors. The recently launched generation two of the design corrects these.  The new Huco Dynatork air motor not only looks the technical product that it has always been but it is now ideal for a wider range of applications.

 On the original design pneumatic tubing was external to the housing.  This made it vulnerable, sensitive to temperature extremes and difficult to clean.  The pneumatic porting on the latest models is now an internal feature making them far more robust.  Fasteners are also recessed to reduce potential bug traps.

 Aluminium foil tray manufacturer Coppice Alupack has systematically replaced all its electric drives on rewind systems that handle the surplus foil after the aluminium coil has been stamped.  Inclusion of Huco Dynatork air motors has not only simplified the design but also made it more controllable and safer.  Their clean, non-lube running has also ensured hygienic production. The Huco Dynatork motors run from 0 – 220 rpm for 24 hours a day in a cycle that goes from stall to start in the order of sixty times per minute.

“The piston air motor has allowed us to adjust most of the tension out of the system to eliminate lacing breakage,” explained Engineering Manager, James Lamin.  “It has also made the process inherently safer by reducing torque and negating the need for any electrical cables.”  A further benefit is that maintenance of the motors can now be carried out by a shop-floor technician instead of a skilled electrician, saving cost and minimising downtime.

The suitability of the Huco Dynatork motor for stop/start applications under load has also been proven by Greydon Inc., the manufacturer of printing equipment for form, fill and seal packaging machinery. Its Bagaire taped bag loader ensure bags are presented quickly and in exactly the same position to the operator, time after time.  This accuracy makes the system ideal for the inclusion of inkjet coding.

The operating principle is simple but effective.  A leader tape is wound around two drive pulleys. When powered up, the system advances the bags by winding up the tape and pulling them up from underneath the load table.  The Huco Dynatork air motor is responsible for this operation and again provides a clean solution that is also suitable for wash down.