How to Select the Right Electric Gear Motor for Bicycle

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An electric gear motor is a combination of a gearbox and an electric motor. It is a cost-effective and simple solution that gives high torque along with a low-speed application as it uses a motor and a gear reducer system. Electric gear motors come with a properly matched electric motor and a gearhead that helps to achieve the desired energy efficiency and also helps in extending the life of your equipment. 

But sometimes, choosing the right gear motor can be tricky for many mechanical and electrical design engineers as there are many factors one must consider. You can even buy a pre-engineered electric gear motor or choose to buy a gearbox and an electric motor separately and then combine them as per your requirements. To make the perfect match, you need to understand the various applications and requirements in your system.

Knowing the Application Requirements for your Electric Gear Motor

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You need to first review your application requirements to choose the right gear motor. This includes the following:

  • Input Power Source – Study the voltage, frequency, control type and maximum current.
  • General Requirements – Analyze the mounting orientation, mounting type and size, lubrication type, envelope size, overhung and side loads and other such factors.
  • Operation Environment – Study the ambient and the application temperature along with the ingress protection rating.
  • Gearmotor performance – Next, you need to analyze the torque, duty cycle, speed, running torque and the horsepower. Also study the starting torque.
  • Gearmotor specifications – This includes analyzing the noise level, life expectancy of the machine, size, weight and also the maintenance level.

Selecting the Right Motor

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Once you have studied the application requirements, you need to compare them to the motor specifications of the motor you are planning to buy. These may include AC induction, brushless DC, universal or even a permanent magnet gearmotor. As each application has its own requirements and characteristics, you need to then choose between better horsepower, efficiency or the starting torque. Most engineers feel that matching a gearbox to an electric motor separately works in their favor and they do not prefer buying the pre-engineered electric gear motor. 

Analyze the Speed and Torque Requirements of the Load to be Moved

The gearmotor should be of the right size for your application. You also need to keep in mind the running torque, starting torque and the output speed. The right gearmotor is just a matter of matching the final output speed and torque with the application’s needs. The final output speed depends directly upon the machine’s requirements and this should be preconceived before. This only leaves you with determining the starting and running torque. While choosing the right pre-engineered electric gear motor, the manufacturer might have already done the heavy lifting to check the seamless performance of the gearbox and the motor.

As soon as the running torque, starting torque has been determined, you should determine the torque, speed and efficiency using a manufacturer’s performance curve. This will help you find a motor that matches your requirements. After that, you should review the limitations of your potential design including the running gearbox torque, gearbox yield strength, input speed, duty cycles and the thermal characteristics.

Testing the Motor

Finally, after selecting the electric gear motor, what remains to be done is to run several tests on the motor to see how it runs in a particular given environment. If your motor becomes too hot or too noisy or if it shows signs of getting too stressed, you can repeat your motor selection process and again choose from the different available options. You can even contact the manufacturer for possible faults.

If you take time to select the proper electric gear motor this way, you will get a machine that will last for years and operate at its best efficiency.

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