Air motors, automation, screwdriving technology and air tools supplier Deprag Schulz is focused on improving its range of stainless steel pneumatic motors, as companies are becoming increasingly reliant on automation and preprocessing, as a result of rising costs.

Deprag notes that, even in the food industry, automated production processes have gained in significance. Further, hygiene is equally important when it comes to the efficiency of the mechanical processing of foodstuffs.

“High-quality stainless steel air vane motors are especially suited to these challenging applications,” says Deprag.

The company’s Advanced Line motor series provides systems engineers with quality stainless steel drives that combine several beneficial features. The robust, sealed design of the motors’ external parts, manufactured with noncorrosive top-quality stainless steel, means that the vane motors are predestined for use in the food industry.

The range of Advanced Line stainless steel motors covers 20 W to 1.2 kW, with idle speeds of between 16 rpm and 24 000 rpm. “It is due to this wide spectrum of stainless steel motors that we are the leader in this market segment. We can provide the ideal solution for any job description,” explains Deprag air motors product manager Dagmar Dübbelde, adding that the sophisticated modular principle offers an outstanding price-performance ratio.

Further, the smooth surfaces of the air motors are easy to clean and the drives repel steam and cleaning agents. The motors are completely sealed, which means that air cannot leak out and dirt cannot penetrate the motor. The seals also allow for the air motor to be used under water. Moreover, the motor does not require special housing and its spindle is able to withstand chemical cleaning agents; it also has a particularly long-life radial shaft sealant ring.

Using this pneumatic motor as a drive offers the end-user various advantages. Deprag highlights power density as the main benefit. Depending on the version of the motor, it has a fifth of the mass of a normal electric motor and is a third of the size. The air motor provides almost constant power over wide torque ranges.

It also works according to a simple principle: the compressed air generated by a compressor rotates the air motor. This functions as a vane motor with the rotor running within an off-centre cylinder. There are vanes in the slots of the rotor which are pressed against the outer cylinder wall by centrifugal force; working chambers are created for the expanding compressed air. It is this expansion of the compressed air which is changed into kinetic energy – and the rotation begins.

Deprag’s air motors have the added benefit of being cool when under increasing load, compared with other drive systems; the expansion cools the frictional heat created. This, therefore, makes the air motors particularly suited to applications in critical surroundings.

Further, they carry the Atex conform seal of approval and are therefore authorised for use in potentially explosive environments. This is particularly important in the food industry when it comes to the processing of flour, as flour dust could ignite if certain temperatures are exceeded. However, the use of an air motor prevents overheating and the ignition of gases.

Meanwhile, Deprag adds that the air motors are flexible and can be optimally operated in a wide field under varying loads. Motor power can be adapted by altering the operating pressure and the speed can be smoothly controlled by throttling the air supply. For specific applications, there are special vanes available. Once the air motor reaches stalling torque – about twice the nominal torque – the air motor will stop. As soon as the load is removed, it runs again without problems. The load can be removed as often as required.

The air motors fulfil all sterilisation and hygiene requirements for use in the food industry. When manufacturing fruit juice drinks, for instance, a mixture is placed in large containers which, after mixing, is heated up to 80 °C, after which juice cartons are filled with the sterile liquid. Agitators are used for mixing and stirring and these must be driven by heat-resistant and robust motors.

The robust, efficient air motors can be adapted to the required torque and operating speed of any application. “Around 85% of our air motor projects are special solutions which we are able to quickly and simply adapt from our standard products for each individual customer,” concludes Dübbelde.