The problem of broken shaft that occurs when the reducer is not concentric

Some users have broken the output shaft of the drive motor after the equipment has been working for a period of time. Why does the output shaft of the drive motor twist off?

When we carefully observe the cross-section of the broken output shaft of the drive motor, we will find that the outer ring of the cross-section is brighter, and the color of the cross-section is darker toward the axis, and there are broken marks (point marks) at the axis. This phenomenon is mostly caused by the inconsistency of the drive motor and the reducer when they are installed.

When the concentricity between the drive motor and the reducer is well ensured, the output shaft of the drive motor only bears the rotational force (torque), and it works smoothly without pulsation. When it is not concentric, the output shaft of the drive motor also bears the radial force (bending moment) from the input end of the reducer. The effect of this radial force will force the output shaft of the drive motor to bend, and the direction of the bending will change as the output shaft rotates. If the error of concentricity is large, the radial force will increase the temperature of the output shaft of the motor, and its metal structure will be damaged continuously, which will cause the output shaft of the drive motor to break due to partial fatigue.

When the error of the concentricity between the two is larger, the time for the output shaft of the drive motor to break is shorter. When the output shaft of the drive motor is broken, the input end of the reducer will also receive the radial force from the output shaft of the drive motor. If this radial force exceeds the radial load that the input end of the reducer can accept, the result will be It will also cause deformation or even breakage at the input end of the reducer or damage to the support bearing at the input end. Therefore, it is very important to ensure concentricity during installation.

From the installation process analysis, if the drive motor shaft and the input end of the reducer are concentric, then the shaft surface of the drive motor and the hole surface of the input end of the reducer will be in good agreement, and their contact surfaces will be closely attached without radial force and deformation. space. If the installation is not concentric, the contact surfaces will not meet or have a gap, there will be radial force and provide space for deformation.

At the same time, the output shaft of the reducer is also broken or bent, and the reason is the same as the broken shaft of the drive motor. However, the output of the reducer is the product of the output of the drive motor and the reduction ratio, which is larger than that of the motor, so the output shaft of the reducer is more likely to be broken. Therefore, when using the reducer, the user should pay more attention to the guarantee of concentricity when installing the output end!