There are various types of coreless motor in the world. Large motors and small motors. A kind of motor that can move back and forth without rotating. At first glance, it is unclear why they are so expensive. However, there is a reason for choosing all types of coreless motor. So, what types of motors, performance, or characteristics are needed for an ideal electric motor?
The purpose of this series is to provide knowledge on how to choose the ideal motor. We hope it will be useful when you select an engine. We hope it can help people learn the basic knowledge of engines.
1. Torque
Torque is the force that causes rotation. coreless motor are designed in various ways to increase torque. The more turns of the electromagnetic wire, the greater the torque. Due to the size limitations of fixed coils, enameled wire with a large diameter is used. Our brushless motor series includes sizes with an outer diameter of 16mm, 20mm, 22mm, 24mm, 28mm, 36mm, 42mm, and 50mm. As the size of the coil also increases with the motor diameter, higher torque can be achieved.
Strong magnets are used to generate large torque without changing the size of the motor. Rare earth magnets are the most powerful permanent magnets, followed by magnesium cobalt magnets. However, even if you only use strong magnets, the magnetism will leak out of the motor, and the leaked magnetism will not increase torque. To make full use of strong magnetism, a thin functional material called an electromagnetic steel plate is laminated to optimize the magnetic circuit.
2. Speed (revolutions)
The speed of an electric motor is commonly referred to as “speed.” It is the performance of how many times the motor rotates per unit of time. Compared to torque, increasing the number of rotations is not technically difficult. Simply reduce the number of turns in the coil to increase the number of rotations. However, since torque decreases as the number of rotations increases, it is important to meet the requirements for both torque and rotational speed.
Additionally, if used at high speeds, it is best to use ball bearings instead of ordinary bearings. The higher the speed, the greater the frictional resistance loss, and the shorter the motor life. Depending on the precision of the shaft, the higher the speed, the greater the noise and vibration-related issues. Since brushless motors do not have brushes or commutators, they produce less noise and vibration than brushed motors (which make contact between brushes and the rotating commutator).
3. Size
When talking about an ideal electric motor, the size of the motor is also one of the important factors in performance. Even if the speed (rotation) and torque are sufficient, it is meaningless if it cannot be installed in the final product.
If you just want to increase speed, you can reduce the number of turns of the wire. Even if the number of turns is small, it will not rotate unless there is a minimum torque. Therefore, it is necessary to find ways to increase torque.
In addition to using the strong magnets mentioned above, increasing the duty cycle of the windings is also important. We have been discussing reducing the number of windings to ensure the number of turns, but this does not mean that the wire is loosely wound.
Replacing the reduction in the number of windings with thick wires can also achieve a large current and high torque at the same speed. The space factor is an indicator of how tightly the wire is wound. Whether it is increasing the number of thin turns or reducing the number of thick turns, it is an important factor in obtaining torque.
Post time: Nov-07-2024