The hollow cup motor is a DC permanent magnet servo and control motor, which can also be classified as a micro special motor. The hollow cup motor has outstanding energy-saving characteristics, sensitive and convenient control characteristics and stable operation characteristics, and the technical advancement is very obvious. As a high-efficiency energy conversion device, it represents the development direction of electric motors in many fields.

Introduction

The hollow cup motor breaks through the structure of the rotor of the traditional motor in structure, and uses an ironless rotor, also known as a hollow cup rotor. This novel rotor structure completely eliminates the power loss caused by the eddy current formed by the iron core.

At the same time, its weight and moment of inertia are greatly reduced, thereby reducing the rotor's own mechanical energy loss. Due to the structural changes of the rotor, the operating characteristics of the motor have been greatly improved. Not only does it have outstanding energy-saving characteristics, but more importantly, it has control and drag characteristics that cannot be achieved by iron core motors.

Motor type

The hollow cup motor is divided into two types, brushed and brushless. The rotor of the brushed hollow cup motor has no iron core, and the stator of the brushless hollow cup motor has no iron core. The winding adopts delta connection.

Main features

The hollow cup motor has the following characteristics:

1. Energy-saving features: The energy conversion efficiency is very high, and its maximum efficiency is generally above 70%, and some products can reach more than 90% (iron core motor is generally 70%).

2. Control characteristics: rapid starting and braking, extremely fast response, mechanical time constant less than 28 milliseconds, some products can reach within 10 milliseconds (iron core motor is generally more than 100 milliseconds); under high-speed operation in the recommended operating area , You can easily adjust the speed sensitively.

3. Drag characteristics: The running stability is very reliable, and the fluctuation of the speed is very small. As a miniature motor, the speed fluctuation can be easily controlled within 2%.

In addition, the energy density of the hollow cup motor is greatly improved, and its weight and volume are reduced by 1 / 3-1 / 2 compared with the iron core motor of the same power.

Principle

The hollow cup motor breaks through the structure of the rotor of the traditional motor in structure, and uses an ironless rotor, also known as a hollow cup rotor. This rotor structure completely eliminates the power loss caused by the eddy current formed by the iron core, and its weight and rotational inertia are greatly reduced, thereby reducing the rotor's own mechanical energy loss. Hollow cup motor belongs to DC, permanent magnet, servo micro special motor.

Classification

The hollow cup motor is divided into two types, brushed and brushless. The rotor of the brushed hollow cup motor has no iron core, and the stator of the brushless hollow cup motor has no iron core.

Application

Because the hollow cup motor overcomes the insurmountable technical obstacles of the iron core motor, and its outstanding characteristics focus on the main performance of the motor, it has a wide range of applications. Especially with the rapid development of industrial technology, higher expectations and requirements are continuously raised for the servo characteristics of the motor, so that the hollow cup motor has an irreplaceable position in many applications.

The application of the hollow cup motor has been rapidly developed in the past ten years from the military and high-tech fields to the large industry and civil fields, especially in industrially developed countries, which has involved most industries and many products.

1. Servo system that needs quick response. Such as the rapid adjustment of the flight direction of the missile, the follow-up control of the high magnification optical drive, fast automatic focusing, highly sensitive recording and testing equipment, industrial robots, bionic prosthetics, etc., the hollow cup motor can meet its technical requirements well.

2. Products that require smooth and durable dragging on the drive components. Such as all kinds of portable instruments, personal personal equipment, field equipment, electric vehicles, etc., the same set of power supplies, power supply time can be extended more than doubled.

3. Various aircrafts, including aviation, aerospace, model airplanes, etc. The hollow cup motor has the advantages of light weight, small size and low energy consumption, which can reduce the weight of the aircraft to the greatest extent.

4. Various civilian electrical appliances and industrial products. The use of hollow cup motors as actuators can improve product quality and provide superior performance.

5. Taking advantage of its high energy conversion efficiency, it is also used as a generator; using its linear operating characteristics, it is also used as a speed-measuring generator; with a reducer, it can also be used as a torque motor.

With the advancement of industrial technology, the strict technical conditions of various electromechanical equipment have put forward higher and higher technical requirements for servo motors. At the same time, the application range of hollow cup motors has completely deviated from the limitations of high-end products and is rapidly expanding in general. The application range of low-end products such as civil is to widely improve product quality. According to relevant statistics, there are already more than 100 civil products in industrially developed countries that have maturely applied hollow cup motors.

Domestic development status

The domestic industry has not fully understood the excellent performance of the hollow cup motor, which has hindered the technological progress of electromechanical products in many fields and seriously affected our technological competitiveness with similar foreign products. Many new products developed in China, because the performance of the motor does not meet the requirements, the overall level of their products has always been far from similar foreign products, which limits the development and development of many products, such as medical devices, prosthetics, robots, cameras, cameras and This phenomenon exists in some special fields, even in textile machinery and laser measuring instruments. However, the production of hollow cup motors, due to their complicated process, is far less automated than iron core motors, resulting in high production costs, high labor costs, and high requirements on the skill level of operators. It brings many difficulties and restrictions to mass production. China has been developing and researching hollow-cup motors for 20 to 30 years, but it has only been developed rapidly since then. It not only replaces imported products in the domestic market, but also has started to participate in competition in the international market.

Key technology

Brushless DC coreless hollow cup motors incorporate a number of key technologies, such as: low rotational inertia, no cogging, low friction and very compact commutation system, these advantages will bring faster acceleration, higher Efficiency, lower Joule losses and greater sustained torque. The hollow cup motor technology reduces volume, weight, and heat generation, making it ideal for similar applications in portable or small devices. This achieves better motor performance in a smaller frame, providing better comfort and convenience for end users. In addition, in battery-powered applications, the ironless design can also extend the life of the equipment and improve energy efficiency.