A group of students asked a question when they visited the factory: Why are the diameters of the shaft extensions obviously different for two motors with basically the same shape? Regarding this content, some fans have also raised similar questions. Combined with the questions raised by fans, we have a simple exchange with you.
The shaft extension diameter is the key to the connection between the motor product and the driven equipment. The shaft extension diameter, keyway width, depth and symmetry all directly affect the final connection and transmission effect, and are also the key objects for the control of the shaft processing process. With the application of automated numerical control equipment in parts processing, the control of shaft processing has become relatively easy.
Regardless of the general-purpose or special-purpose motors, the shaft extension diameter is related to the rated torque, and there are very strict regulations in the technical conditions of motor products. Any failure of the assessment factor will lead to the failure of the whole machine. As the basis for the selection of the supporting motor for the customer’s equipment, it will also be clearly indicated in the product samples of each motor factory and consistent with the technical conditions; and for the shaft extension size different from the standard motor, it is uniformly attributed to the non-standard shaft extension. When such requirements are required, technical communication with the motor manufacturer is required.
Motor products transmit torque through the shaft extension, the diameter of the shaft extension must match the transmitted torque, and the size must be able to ensure that the shaft extension does not deform or break during the operation of the motor.
Under the condition of the same center height, the diameter of the shaft extension is relatively fixed. Generally, the diameter of the shaft extension of the 2-pole high-speed motor is one gear smaller than that of the other 4-pole and above low-speed motors. However, the diameter of the shaft extension of the low-power motor with the same base is unique, because the size of the transmitted torque is not enough to affect the diameter of the shaft extension, there will be a qualitative difference, and the versatility is the dominant factor.
Taking a concentric motor with high power and different pole numbers as an example, the rated torque of the motor with a small number of poles and high speed should be small, and the rated torque of the motor with a large number of poles and low speed should be large. The size of the torque determines the diameter of the rotating shaft, that is, the torque of the low-speed motor is relatively large, so it will correspond to the larger diameter of the shaft extension. Because the power spectrum covered by the same frame number may be relatively wide, sometimes the shaft extension diameter of the motor with the same speed is also divided into gears. In view of the universal requirements of motor parts with high concentricity and high number of poles, it is better to set different shaft extension diameters according to the number of poles of the motor under the condition of high concentricity and height, so as to avoid subdivision under the condition of high concentricity and high number of poles. .
According to the difference of the motor torque under the condition of the same center, high power and different speeds, what the customer sees is only the difference in the diameter of the motor shaft extension, and the actual internal structure of the motor casing is more different. The outer diameter of the rotor of the low-speed, multi-pole motor is larger, and the layout of the stator winding is also significantly different from that of the few-stage motor. Especially for 2-high-speed motors, not only the shaft extension diameter is one gear smaller than other pole-number motors, but also the outer diameter of the rotor is extremely small. The length of the stator end occupies a large proportion of the motor cavity space, and there are many ways of electrical connection at the end. And many products with different properties can be derived through electrical connection.
In addition to the difference in the diameter of the motor shaft extension, there are also some differences in the shaft extension and rotor type of motors for different purposes. For example, the shaft extension of the lifting metallurgical motor is mostly conical shaft extension, and some motors for cranes and electric hoists are required to be conical rotors. Wait.
For motor products, in view of the requirements for the serialization and generalization of parts and components, the shape and size of the parts contain specific performance characteristics. How to truly understand and read these size codes is really a big technology. subject.
Post time: Jul-14-2022