A brief discussion on the driving force of the development of the flat wire motor industry for new energy vehicles

Innovation opportunities:

Rare earth-free motor: The advantage of induction AC asynchronous motor is that it does not require rare earths, but the disadvantages are low torque density and power density, and large size. Currently, there is still a 3-5 year technical window for actual mass production application.

Currently, many international tier-1 companies are conducting relevant research and development, but due to my country's large rare earth production and reasonable prices, and the fact that motors without rare earths have a significant performance disadvantage, such demand is not urgent at present.

2.1.2 Copper wire material

my country is the world's largest producer and export base of electromagnetic wire, but the electromagnetic wire industry is fragmented and competition is fierce.

In 2020, CR6 was only 25.8%. According to data from the China Electrical Industry Association, the demand for electromagnetic wire in China reached 1.8 million tons in 2020, with more than 1,000 manufacturers in the industry, and a significant long-tail effect.

Flat wires are difficult to manufacture and it is expected that the market will concentrate on the top players after the volume increases.

Since the insulating coating of the flat wire will shrink unevenly after drying, it is easy to deform and become thinner at the four corners, affecting the insulation. It is necessary to improve the coating thickness at the R corner. It is difficult to apply the paint film at the R corner of the flat wire, and it is difficult to ensure the uniformity of the insulating layer. After the flat wire is bent into a hairpin, the stress is concentrated at the R corner, which can easily cause damage to the coating layer. Therefore, high requirements are placed on the accuracy and quality of the copper wire and its coating.

2.1.3 Production equipment

The manufacturing process of flat wire motors is complex, including 100-400 parts such as stators, rotors, reduction gearboxes, motor controllers , etc., which are assembled in the order of the drive motor product process flow.

It is usually composed of the final assembly line, testing line, stator sub-assembly line, rotor sub-assembly line, motor control sub-assembly line, and reduction gearbox sub-assembly line. The key processes include: PI N line forming, automatic twisting, coating, etc.

Flat wire motors have high requirements for product consistency and are technically difficult. They require investment in high-precision automated servo equipment, welding equipment, Hair-Pin wire forming equipment, and tooling molds. They have high requirements for equipment automation and are mainly dependent on imports.

The localization of related equipment mainly faces three difficulties: high investment, low degree of solution standardization and high requirements for automated process.

In the past, it mainly relied on imports. A relatively mature flat wire motor industry chain has been formed abroad. The main suppliers of flat wire motor manufacturing equipment include Italy's TE CNOMATIC , Italy 's ATOP, Germany's GROB Group, Japan's Odawara Engineering Co., Ltd. and Austria's Miba Group. In China, only a few equipment manufacturers such as Kelai Electromechanical, Hausen Co., Ltd. and Juyi Technology have the ability to manufacture flat wire motor equipment. Among them, Kelai Electromechanical supplies United Electronics , Hausen Co., Ltd. supplies Shanghai Loongson, etc.

Production line equipment suppliers mainly provide motor manufacturers with the design, manufacture and commissioning of intelligent production lines and equipment. They are asset-light models with high gross margins and large profit margins.

Such manufacturers generally provide a complete set of turnkey projects including planning, R&D, design, assembly, commissioning and services. The business model is mainly divided into two types: complete line assembly and stand-alone equipment sales. The former has a higher unit value, with an average production line value ranging from tens of millions to more than 100 million yuan, and a gross profit of about 40%.

Since the flat wire motor has a high technological threshold and relies on more precise automation equipment , the investment in the production line is greater than that of the traditional round wire, and the equipment supplier can enjoy a higher profit margin. The high investment of the motor manufacturer in the production line is transferred to the equipment and becomes high value. Moreover, the equipment supplier only needs to purchase parts for the assembly of the production line, which is a light asset model compared with the motor manufacturer.

The complete manufacturing process of flat wire motor stator components includes paper insertion, coil forming, pre-insertion, overall insertion, flaring, twisting, cutting, welding, coating and dipping, and copper nose welding. The processes are numerous and complex, and the degree of dependence on equipment is higher than that of round wire motors. In particular, the coil forming and welding processes require high precision and great difficulty, and require the use of professional high-end equipment. Overseas companies have profound accumulation in this field and have obvious first-mover advantages in equipment; domestic companies are actively developing and following up based on the huge domestic application market.

The production process of drive motors can be divided into two stages: component production and final assembly testing:

-The key process steps in the component production stage include: stamping, lamination, and welding of stator core and rotor core; stator winding, wire embedding, and varnishing; casting and CNC machine finishing of housing, front and rear end covers, and transmission housing; forging and CNC precision machining of shafts and gears; rotor assembly, etc. Finally, each component is tested and sent to the final assembly workshop for assembly testing.

-The key steps in the final assembly and inspection phase include: casing casting and CNC machining, end cover casting and CNC machining, stator assembly, rotor assembly, assembly of modules and wiring harnesses, performance testing, etc.

✓ Drive motor assembly process

The main conventional workstations of the motor assembly line (for example): water jacket hot installation station, bearing hot installation station, stator shell installation station, electrical testing station, stator and rotor assembly station, leak test station, etc., as well as intelligent communication and MES data management system

Core technologies: key dimension control of stator shell, water jacket hot-installation temperature control, motor assembly safety performance control, robot fuzzy grasping technology

✓ The manufacturing process of flat wire motor stator assembly includes: paper insertion, coil forming, pre-insertion, overall insertion, flaring, twisting, cutting, welding, coating and varnishing, copper nose welding;