Electric motors are produced in almost unmanageable variety. They are available as tiny little motors, for example in toys. As motors of medium power, they compete with the combustion engine, for example in garden tools. Large motors, for example, provide the drives for electric machine tools. But it is not only the design of these motors that differs. They are also offered in a number of basically different types.
How does an electric motor work
The electric motor is in principle a very old technology that converts electrical energy into mechanical energy. The current used can be direct current, alternating current or three-phase current, from the socket, from an accumulator or from batteries.
In the electric motor, the interactions of magnetic fields are used to generate a rotary motion. A usually fixed outer part is opposed by a movable inner part. These two parts can either both consist of a current carrying coil or one of the components is a permanent magnet. A magnetic field is created around each coil through which a current flows. The orientation of this field depends on the direction of the current.
The moving inner part is set in rotation by the repulsive forces of the magnetic fields. This movement is converted into mechanical energy via a shaft.
Direct current motors have a permanent magnet as a fixed part. If the direction of the current in the moving coil is changed, its direction of rotation changes as well. If the motor is operated with alternating current or three-phase current, the fixed part must also consist of a coil, because otherwise the direction of rotation would constantly change according to the frequency of the current. Alternating current motors, and especially three-phase motors, generally have a greater power output than direct current motors. The power of the motor also depends on the voltage used.
The advantages of the electric motor compared to a combustion engine
The electric motor is much simpler in design and therefore cheaper to produce than a combustion engine. This motor has a high efficiency of about 90%. The efficiency of the combustion engine is about 30%. An electric motor is much quieter. The electric motor reaches full torque very quickly. The combustion engine, on the other hand, must first reach a certain speed to achieve optimum torque.
Which criteria are important when choosing a manufacturer?
Numerous manufacturers offer electric motors in a wide variety of designs, power ratings and construction types. To find a suitable manufacturer, it is worth comparing the offers. The following questions are of interest in this comparison. How large is the selection of suitable motors from this manufacturer? Does it offer purchasing advice? Is a customer service available for any help that may be required with the installation of the motor? What are the delivery times for the type of engine you require? Is there a repair service available?