A good motor core needs to be stamped out by a precision hardware stamping die using an automatic riveting process, and then using a high-precision stamping press table, which can guarantee the integrity of the plane and accuracy of its products to the greatest extent.

As an advanced forming and processing technology that integrates various technologies such as equipment, dies, materials and processes, the modern stamping technology of motor stator and rotor core parts is to use a multi-station progressive die with high precision, high efficiency and long life, which integrates all processes in one die to carry out automatic punching on a high-speed punching machine. The whole process of punching, forming, finishing, edge cutting, automatic electric motor rotor laminations, twisted slant lamination, and rotary lamination, etc. can be completed continuously until the finished core parts are transported out of the mold.

With the continuous development of the motor manufacturing process, modern stamping technology has been accepted by an increasing number of motor manufacturers, and the processing means of manufacturing motor cores are becoming more and more advanced. Compared with the core parts stamped with ordinary molds and equipment, the core parts stamped by modern stamping technology have high degree of automation and high-level dimensional accuracy, the molds have long service life, and the modern stamping technology is suitable for mass production of stamping parts.

1. Modern high-speed stamping equipment

The development trend of modern stamping technology at home and abroad is single machine automation, mechanization, automatic feeding, automatic unloading and automatic output of finished products. The stamping speed of the progressive die for motor stator core is generally 200-400 times/min, which is mostly within the range of medium speed stamping.

As the materials stamped by the progressive die are in the form of rolls, modern stamping equipment is equipped with auxiliary devices such as uncoiler and leveler. Automatic feeding devices in the form of rolls, cams, mechanical stepless adjustment, gears and CNC stepless adjustment feeders are used with the corresponding modern stamping equipment respectively.

Due to the high degree of automation and fast speed of modern stamping equipment, in order to fully guarantee the safety of the die in the stamping process, modern stamping equipment is equipped with an electrical control system in case of failure. If the die fails in the stamping process, the failure signal will be immediately transmitted to the electrical control system, and the electrical control system will send a signal to stop the stamping machine immediately.

2. Modern die stamping technology for motor stator and rotor cores

In the motor industry, the stator and rotor core is one of the important parts of the motor, and its quality directly affects the technical performance of the motor. The traditional method of making core is to use the general common mold to stamp electric motor rotor laminations, and then use rivet riveting, buckle piece or argon arc welding process to make the core.

With the rapid development of high-speed stamping technology, high-speed stamping multi-station progressive die has been widely used to manufacture automatically stacked structural cores. Compared with ordinary stamping die, multi-station progressive die has high stamping accuracy, high production efficiency, long service life, good consistency of the core size, and easy automation.

The progressive die with automatic lamination riveting technology is to put the original traditional core making process in one die, that is, on the basis of the progressive die, the new stamping technology is added. The process of automatic core lamination formation is: lamination riveting point with certain geometric shape is punched on the appropriate part of the stator and rotor laminations, and then the raised part of the upper lamination with the same nominal size is embedded in the recessed hole of the next lamination, so as to achieve the purpose of tightening the connection.

The thickness of stator core laminations is controlled by punching through the lamination riveting point on the last lamination at the predetermined number of the core laminations, so that the core is separated by the predetermined number of laminations.

3. Current status and development of modern die stamping technology for motor stator and rotor cores

Motor stator and rotor core automatic laminating technology was first proposed and successfully developed by the United States and Japan in the 1970s, thus making a breakthrough in the manufacturing technology of motor cores and opening up a new way for high-precision automatic core production. China started the research and development of the progressive die technology from the mid-1980s through the digestion of introduced mold technology, absorption of practical experience. Through independent development of such molds and the localization of promising results, China finally is able to develop such high-grade precision molds from the original relying on the introduction of such molds.

Especially in the last 10 years, with the rapid development of China’s precision mold manufacturing industry, modern stamping die as a special process equipment has become increasingly important in the modern manufacturing industry. Motor stator core modern stamping die technology has also developed comprehensively and rapidly.

At present, the modern stamping die technology of China’s motor stator and rotor core is mainly reflected in the following aspects, and its design and manufacturing level is close to the technical level of similar foreign dies.

1. The overall structure of the motor stator and rotor core progressive die (including double guide device, unloading device, guide device, step guide devices, limit devices, safety detection devices, etc.).

2. Structure form of core lamination riveting point.

3. Progressive die with automatic lamination riveting technology, twisting and turning technology.

4. Dimensional accuracy and core fastness of stamped cores.

5. The degree of standard parts selected on the mold.

4. Conclusion

The use of modern stamping technology to manufacture the stator and rotor cores of motors can greatly improve the motor manufacturing technology, especially in automotive motors, precision stepper motors, small precision DC motors and AC motors, etc. China motor stator and rotor core progressive die manufacturers have gradually developed with improving design and manufacturing technologies.

Gator Precision, a comprehensive enterprise integrating mold manufacturing, silicon steel sheet stamping, motor assembly, production and sales, designs and produces high-quality electric motor rotor laminations. For any further information, just contact us.