The center hole of the motor shaft is the benchmark of the shaft and rotor machining process. The center hole on the shaft is the positioning reference for the motor shaft and rotor turning, grinding and other processing procedures. The quality of the center hole has a great influence on the precision of the workpiece processing and the life of the machine tool tip.
There are three main types of center hole: Type A unprotected taper hole, used for shafts that do not need to retain the center hole; Type B with 120-degree protection taper hole, which can avoid damage to the main cone surface of 60 degrees, and is the most suitable for motor products. Commonly used center hole; C-type hole has screw holes, which can fix other parts; if it is necessary to connect and fix parts on the shaft or facilitate hoisting, C-type center hole is generally used; vertical motors and traction motors are more commonly used C-shaped center hole.
When the customer requires the use of the C-type center hole, it should be mentioned in the technical requirements of the motor order, otherwise the manufacturer will process it according to the B-type hole, that is, to meet the basic needs of the motor body manufacturing and later maintenance.
GB/T 145-2001 “Central Hole” is the current version of the standard, replacing GB/T 145-1985, which is a national recommended standard. However, once the recommended standard is adopted, it should be processed according to the specified size of the standard, which is a rule to ensure that both the manufacturer and the user follow.
In the process of motor shaft and rotor machining, the center hole is the key element of quality control. If the surface of the center hole is damaged, or there are foreign objects in the hole, the processed parts may not meet the requirements, especially for the same parts of the motor parts. Axis control is seriously affected. In the post-maintenance process of the motor, most of the center holes will be used. Therefore, the center hole of the motor shaft will accompany the entire life cycle of the motor.
In the actual motor repair or modification process, the center hole of the motor shaft may be damaged for some reason. For example, when changing a double-shaft motor to a single-shaft motor, many operations are directly sawing off the auxiliary shaft. The central hole also disappears thereupon, and this type of rotor basically loses the basic conditions for mechanical performance repair.
Post time: Apr-07-2023