Comprehensive analysis of stator core of axial flux motor

Overview of stator core of axial flux motor
As a high-performance type of motor, the stator core of axial flux motor is a key component. The stator core, also known as the stator core, is an important component that forms the magnetic flux circuit and fixes the stator coils of a motor. It is composed of punched pieces and various fasteners that are pressed together to form a whole. The stator core plays an important role in generating the excitation magnetic field in the motor, exerting force on the energized conductor inside, and is a part of the main magnetic flux circuit of the axial flux motor.

In order for the axial flux motor to generate a large electromagnetic torque, a strong rotating magnetic field is required. Due to the synchronous rotation of the stator core by the rotating magnetic field, the magnitude and direction of the magnetic flux in the stator core vary. Therefore, it is necessary to find ways to reduce the eddy current loss and hysteresis loss caused by the rotating magnetic field in the stator core. Usually, the stator core is made of laminated silicon steel sheets with a thickness of 0.35-0.5 millimeters and a certain shape, which have good magnetic conductivity.

Structural composition of stator core of axial flux motor
The stator core of an axial flux motor is usually composed of punching plates, ventilation slots, positioning ribs, upper and lower tooth pressure plates, tension bolts, and support plates. These parts are assembled into a whole through precision manufacturing processes to ensure that the stator core has good magnetic conductivity and structural strength.

Stamping is the basic component of the stator core, usually made by punching silicon steel sheets. For punching pieces with an outer diameter less than 1m, use round punching pieces, and for punching pieces larger than 0.99m, use fan-shaped punching pieces. The ventilation groove is composed of fan-shaped punching plates, ventilation channel steel, and lining rings, which are used to form stator ventilation grooves to ensure good heat dissipation during the operation of the motor. The ventilation channel steel and lining ring are fixed to the fan-shaped punch plate by spot welding, and the spot welding spacing and the size of the channel steel elbow need to be strictly controlled to avoid damaging the winding. The positioning rib is welded onto the machine base ring plate through a support plate, and the iron core is tightened with tension bolts through the upper and lower toothed pressure plates.

Material selection of stator core for axial flux motor
The material selection of the stator core is crucial to its performance. Silicon steel sheets have become the primary choice for manufacturing stator cores of axial flux motors due to their excellent magnetic conductivity and low loss characteristics. Silicon steel sheet is a thin steel plate with extremely low carbon content. Through special controlled production conditions, hysteresis loss and eddy current loss can be significantly reduced. The addition of silicon element increases the resistivity, thereby reducing eddy current losses.

The silicon steel sheets used in motors are divided into two types: cold-rolled and hot-rolled, with cold-rolled silicon steel sheets further divided into oriented and non oriented types. Non oriented silicon steel sheets have been widely used in the stator core punching of large hydroelectric generators due to their isotropy. In addition, for some axial flux motors with special requirements, materials such as iron nickel soft magnetic alloy thin plates may also be used to manufacture the stator core.

Manufacturing process of stator core for axial flux motor
The manufacturing process of the stator core of axial flux motor is complex and precise. Firstly, it is necessary to punch the silicon steel sheets into fan-shaped or round punched sheets according to the design requirements. The number of slots on each fan-shaped sheet must be an integer, and the gaps and chamfers at the joints must be designed reasonably to prevent damage to the winding insulation. Next, stack the fan-shaped or round punched pieces onto the positioning ribs and press them together as a whole using upper and lower toothed pressure plates and tension bolts. In order to ensure the quality of stacking, the staggered stacking method is usually used to reduce the impact of additional air gaps on electromagnetic performance.

The design and manufacturing of ventilation slots are also important links in the manufacturing process of stator cores. The ventilation groove is composed of fan-shaped punching plates, ventilation channel steel, and lining rings, which are used to form stator ventilation grooves to ensure good heat dissipation during the operation of the motor. The ventilation channel steel and lining ring are fixed to the fan-shaped punch plate by spot welding, and the spot welding spacing and the size of the channel steel elbow need to be strictly controlled to avoid damaging the winding.

Performance requirements for stator core of axial flux motor
The design of the stator core of an axial flux motor needs to meet a series of basic requirements. Firstly, good magnetic conductivity and low loss are key factors. Good magnetic conductivity can generate a large electromagnetic torque in the motor, while low loss can improve the efficiency of the motor and reduce energy waste. Secondly, good stiffness and low vibration are also important performance indicators. The stator core needs to have sufficient rigidity to ensure the stability of the motor during operation and reduce the generation of vibration and noise.

In addition, the stator core needs to have good ventilation in its structural arrangement to dissipate heat and reduce temperature rise. The motor generates heat during operation, and if it cannot dissipate heat in a timely manner, it will affect the performance and lifespan of the motor. Finally, the inner diameter and slot size of the laminated iron core should meet the design accuracy requirements to ensure the normal installation and operation of the stator winding. For special motors such as large hydro generators, it is also necessary to ensure the gap between the split iron cores, otherwise it will cause iron core vibration during motor operation.

Application and Development Prospects of Stator Core in Axial Flux Motor
The stator core of axial magnetic flux motors has broad application prospects in fields such as electric vehicles, aerospace, and industrial automation. In the field of electric vehicles, axial flux motors have the advantages of high power density, high efficiency, and small size, which can improve the range and performance of electric vehicles. As a key component of axial flux motors, the performance of the stator core directly affects the performance of the motor and the overall performance of electric vehicles.

In the aerospace field, axial flux motors can be used for electric propulsion systems of aircraft, accessory drives of aircraft engines, etc. The high-performance and lightweight design of the stator core can meet the strict requirements of the aerospace industry for motors. In the field of industrial automation, axial flux motors can be used in equipment such as robots and CNC machine tools to improve the accuracy and efficiency of the equipment.

With the continuous development of technology, the technology of axial flux motor stator core is also constantly advancing. In the future, the materials of stator cores will become more diversified, the manufacturing process will be more precise, and the performance will be superior. At the same time, the design of the stator core will also pay more attention to matching and coordinating with other components of the motor to improve the performance and reliability of the entire motor system. For example, by optimizing the structure and material of the stator core, the power density and efficiency of the motor can be further improved, the volume and weight of the motor can be reduced, and the cost can be lowered. In addition, with the development of intelligent manufacturing technology, the manufacturing process of stator cores will become more intelligent and automated, improving production efficiency and product quality.