Principle analysis of hollow cup motor.
The hollow cup motor breaks through the traditional rotor structure of electric motors in terms of structure, using a coreless rotor, also known as a hollow cup rotor.
This novel rotor structure completely eliminates the electrical energy loss caused by eddy currents formed by the iron core, while significantly reducing its weight and rotational inertia, thereby reducing the mechanical energy loss of the rotor itself. Due to the structural changes of the rotor, the operating characteristics of the electric motor have been greatly improved. It not only has outstanding energy-saving features, but more importantly, it has control and drag characteristics that iron core motors cannot achieve.
Hollow cup electric motors mainly include:
1. Energy saving features: The energy conversion efficiency is very high, with a maximum efficiency generally above 70%, and some products can reach over 90% (iron core motors are generally at 70%).
2. Control characteristics: Fast starting and braking, extremely fast response, mechanical time constant less than 28 milliseconds, some products can reach within 10 milliseconds (iron core motors generally have a time of over 100 milliseconds); In the recommended operating area, the speed can be easily and sensitively adjusted during high-speed operation.
3. Dragging characteristics: The stability of operation is very reliable, and the fluctuation of speed is very small. As a micro motor, its speed fluctuation can be easily controlled within 2%. In addition, the energy density of the hollow cup motor is significantly increased, and compared with iron core motors of the same power, its weight and volume are reduced by 1/3-1/2.
Hollow cup electric motors have the following advantages:
1. Maximum energy conversion efficiency (a measure of its energy-saving characteristics): Its efficiency is generally above 70%, and some products can reach over 90% (ordinary iron core motors are between 15-50%);
2. Quick activation, braking, and extremely fast response: The mechanical time constant is less than 28 milliseconds, and some products can reach within 10 milliseconds. In the recommended high-speed operating range, the speed adjustment is sensitive;
3. Reliable operational stability: Strong adaptability, able to control speed fluctuations within 2%;
4. Low electromagnetic interference: using high-quality electric brushes and commutator structures, with small commutation sparks, can eliminate the need for additional anti-interference devices;
5. High energy density: Compared with iron core motors of the same power, its weight and volume are reduced by 1/3-1/2; The corresponding parameters of speed voltage, speed torque, torque current, etc. all exhibit standard linear relationships.
