Guideline for airmotor selection

It only takes 6 steps to establish the optimal technical data

Guidline-Air Vane Motors

1. Operating conditions:

Air motors are overload safe which means they can be loaded until standstill without problems and without any damage. The DEPRAG air motors in our catalogs are already equipped with a suitable gear box.
If you require a drive that is overload safe (stall proof) or even self retaining then you should select a standard airmotor with appropriate gear that fits your requirements.

2. Which material is best suited for your application?

Your individual application determines the material and execution of the air motor. Beyond the products shown in our standard catalog, we can offer customized drive system for your application. A custom solution assures that the pneumatic motor fits your application and will operate safely.

Standard operating procedure
In dry environments and for standard operating procedures, an airmotor made from cast-iron is the right solution. Here, we can offer the wide product range of the DEPRAG BASIC LINE Air Motors. For integration with robots or into machines, we offer a multitude of grinding, milling, and dril motors, which excel due to their low weight and compact design.

Paper Industry
An airmotor used in the paper industry requires stainless steel. The DEPRAG ADVANCED LINE Air Motors made from stainless steel fulfill the highest requirements in this industry.

Food Industry
Airmotors used in the food industry must be resistant to cleaning agents and water vapor. The DEPRAG ADVANCED LINE Air Motors are fully sealed. All seals are made from resistant materials.

Chemical Industry
Air motors for the use in the chemical industry have to be resistant to aggressive chemicals. Please tell us below the chemicals that the airmotor comes in contact with and we select the suitable material to manufacture your airmotor. Especially in this industry, an airmotor has to be explosion proof. Your DEPRAG airmotor made from stainless steel fulfills the ATEX norm and is additionally fully sealed.

Under Water Operation
When using a pneumatic motor under water, its performance depends on how you operate your air motor and at what depth.
If the airmotor is started outside of the water and subsequently submerged in water up to a depth of 20 m, then the DEPRAG ADVANCED LINE Air Motors made from stainless steel can be used.

If the air motor starts below the water surface, then our ADVANCED LINE Air Motors can be used up to a depth of 5 m.
If you have more difficult requests or would like to use the airmotor in saltwater, then, additional modifications have to be made to the housing material, to seals and to the coating of interior parts, please contact us with more details.

Medical Technology
Airmotors used in medical technology and the pharmaceutical industry are mostly operated under sterile conditions. Special materials assure a high lifespan despite frequent sterilization of the complete pneumatic motor.

Explosion Hazardous Areas
Due to its construction and functionality, the airmotor is the primary choice for use in explosion proof areas. The expanding air cools the airmotor during operation. In combination to gears and brakes, there are risks. For those extreme conditions, DEPRAG offers the worlds first ATEX compliant total system of airmotor, holding brake and gear box.

3. Calculation of the motor performance when considering the operating conditions?

The correct calculation of your drive depends on the desired rotational direction, the optimal operating range, the required airmotor power and the special operating conditions that influence the motor's performance.

3.1 Turn direction

Determine the desired rotational direction (view from air inlet) for your airmotor.

3.2 Optimal operating range of your airmotor

Airmotors operated in very wide operating ranges can be decisively influenced by the air volume and the air pressure.

First, determine the operating point for your airmotor:
What nominal torque and what speed (under load) would you like to achieve?

The most economic use of the pneumatic motor (lowest wear, lowest air consumption, etc.) is reached when the motor operates close to the nominal speed.

3.3 Calculation of motor power

First, calculate the basic power data of your pneumatic motor (existing airpressure, cross sections of air openings, oilfree operation), that is then added to your framework conditions.

Do you have problems determining your power data?
Please contact our application experts, they are standing by to help you.

Do you wish to determine the power data of an existing drives?
We can offer you an extensive testing service to determine the power data of your existing drives (airmotors, hydraulic motors or electric drives, grinders, drills, etc.)

With our modern computer controlled performance test station, we can determine the parameters of power, speed, torque, operating pressure, air consumption and humidity in the
speed range 0 - 120,000 rpm and in a
torque range of 0 - 500 Nm
with an accuracy of 0.1% of the nominal torque.

3.4 Giving considerations to performance influencing operational conditions

a) Considering a fluctuation operating pressure

All performance specifications are based on a sustained operating pressure of 6 bar. Operating pressure is the flow pressure that occurs directly on the airmotor. You can use the shown correctional diagram or the correctional table to customize the differences in the operating pressure. You can click the diagram to expand it.

b) Giving considerations to cross section limitations

The required ID of the air supply hose is stated for each pneumatic motor in the catalog (and that also includes all fittings, connectors and valves). You can also find the maximum length of the air supply hose (max. 3 meters). This all influences the performance calculation. If needed, you can adjust the standard airmotor to your requirements by throttling the air volume. We supply power graphs for all our airmotors. If needed, please contact us. By throttling the air inflow, the speed of the airmotor and torque is reduced. If you wish to reduce the speed of the motor without reducing the torque output, it is recommended to throttle the exhaust air of the pneumatic motor.

c) Giving considerations to oilfree operation

The specifications in the catalog are based on lubricated operation.
The maximum longevity and performance of your airmotor is reached by oiling the motor with 1 to 2 drops of oil per 1m3 air consumption. Please find the performance data in each product catalog. If the airmotor is used without lubrication, then a performance loss of 10 to 20% occurs.

4. How do you plan to integrate the air motor into your overall system?

In addition to the pneumatic motor of your choice, we can now also offer additional components to complement your system. Those components are included in our standard product line.

4.1 Integrated Holding Brake

For example, if a brake needs to hold the position of a barrel during a tipping process, then a DEPRAG standard system can accommodate this requirement.

4.2 Integrated Gear Solutions

A total solution often is more cost effective than to look for a gear solution by yourself. DEPRAG offers a comprehensive assortment of airmotors with integrated planetary gearbox, worm gear or spur gearbox.

A spur gearbox is recommended if your machine requires the self retention. A planetary gearbox is small and allows variable mounting positions.

If you cannot find a suitable airmotor in out catalog, we can provide many cost effective alternatives.

4.3 Mounting and Connection Dimensions

In addition to the standard airmotor fittings in our catalog, there are numerous mounting options (foot, flange, etc.) available to ensure that the airmotor will propperly fits in your machine.
Please let us know your requirements and we will offer you a cost effective solution.

4.4 Technical Checkup

How does the force of your machine effect the drive spindle of the motor?
The maximum allowable axial and radial forces can be found in our catalogs.

5. Wie sichern Sie eine lange Lebensdauer und die hohe Leistung Ihres Motors?

Airmotors are exceedingly powerful and still durable and robust. By following basic requirements, an airmotor reaches its maximum lifespan and its highest performance.

General Requirements

  • Compliance with recommended air quality (dry, clean air supply).
  • Optimal longevity and best performance is reached when lubricating the motor with 1 to 2 drops of oil per 1m3 air consumption.
  • Observe the recommended maintenance intervals. When using a motor with unlubricated air, then the maintenance intervals need to be shortened accordingly.
  • Allow for sufficient cross section of the air supply hose and all connectors.
  • The maximum length of the air supply hose is 3 m.

If you airmotor has not been in use for a long time, here is a helpful tip:
Drip one drop of oil into the air inlet and let the airmotor run for 5 to 10 seconds.

With lubrication your pneumatic motor will be protected for unuse and storage. You will see that once you restart your airmotor, it will be in great condition for a long time.

6. Wie bewerten Sie die Anschaffungs- und Folgekosten?

The purchase price is the main criteria for the purchase of a new driving system. Nevertheless, the follow up costs should not be disregarded.
The operating cost, as well as cost for maintenance and service of an airmotor should be taken into account when making your buying decision.

The operating costs are decisively determined by the air consumption. The correct selection of the airmotor sets the course for low operating costs. You should try to operate the airmoter close to the nominal speed, 50% of the idle speed. At the nominal speed the pneumatic motor will work at the highest power output and the air will be used most efficiently. 

Spare Parts and Repair Kits

When designing your machine, you consider the availablility and cost of spare parts. Spare parts for DEPRAG airmotors are particularly cost effective and are readily available.

Maintenance and Repair ServiceDEPRAG offers flatrate maintenance and repair services in order to simplify the calculation of followup costs.

Time is money:
How easy is it to maintain your airmotor? The BASIC LINE Air Motor is especially easy to maintain due to its QuickVChange Vane Exchange Feature. The vanes of the airmotor can be exchanged directly on your machine with just a few steps so that idle times remain short.

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