Our bespoke solution for your low speed air motor

1 juillet 2016


Certain functions using air motors require precision movement and/or a slow rotation speed. Take for example, the valve industry. If you open a valve too quickly, you risk bursting the pipe. Or the crane industry, where heavy loads have to be lifted, rotated and lowered very carefully.

Pneumatic motors reduce the rotation speed by using planetary gearing. However reducing the speed has the effect of increasing the torque, so we have to find a way of regulating the torque in order to protect the motor and, more importantly, the client’s machine and the person operating it!

Rotation speed of just 1 rpm for a specific application in the nuclear industry 

We first encountered this issue when working with a client in the nuclear industry. The company required a motor with a rotation speed of just 1rpm (which involves very high reduction) for a specific application. This meant we had to find a way to control the torque but without installing a large, heavy gear box that would normally be needed to achieve this. We found a solution by incorporating a small torque limiter into the motor.

Building on from this experience, our team has designed a wide range of torque limiters that can be adapted and used in unlimited combinations to respond to our clients’ needs. We have two basic prototypes:

#1  A small torque limiter ...

... which is placed in the middle of the air motor as an integral part. Placing it between the pneumatic part and the gearbox means you can manage a large torque with a smaller torque switch. The advantage of this option is a lighter motor adapted for use in smaller spaces.

#2  A larger torque limiter ...

... which is effectively a separate module added to the end of the motor. This is suitable for use in machines based in the plant or workshop, or in situations where space is not restricted.

Low speed motors in valve manufacturing industry, aircraft industry, chemical refineries

An added advantage of Modec torque limiters is that you can either set the motor to disengage once the maximum or selected torque limit is reached, or you can opt to receive a signal that indicates the limit has been reached giving you the option to either stop the motor or any othet action (for example change the rotation direction, or change the supply air pressure).

We have clients using our low speed motors in the French valve manufacturing industry and aircraft industry (for slow-moving conveyors), in chemical refineries in China, as well as a major water supply company in France. Given that every business will have a different requirement, we prefer to work with clients individually to design and build on demand a low-speed air motor that meets their specific needs.

Don’t hesitate to contact us and find out what we can do for you, or to download our case studies ! 

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