As a key component of the motor, the bearing has a great impact on the mechanical properties and even the overall performance level of the motor, so the selection of the motor bearing has become the focus of any manufacturer and user.
In order to ensure the safety of motor use, many motor consumers put forward requirements for bearing brands in the ordering process, and some customers will make specific provisions on the specifications of motor bearings. As a motor manufacturer, according to the actual operating conditions of the motor, on the basis of the standard motor bearing configuration, the necessary optimization technical measures will be carried out, such as the selection of bearing clearance, the selection of fixed end and free end bearings, etc.
Combined with my knowledge accumulation in the process of motor testing and fault disposal, I hereby put forward the following opinions and suggestions for your reference!For the selection of bearing specifications, it should be based on the fact that the unified design of the motor and repeated verification, it is not recommended to change the size of the bearing specifications too much, but a small range of adjustments can be made in other aspects
First, the clearance of the motor bearing is in accordance with the principle of high speed and large clearance, for the motor with 8 poles and below the power frequency, it is recommended to choose C3 clearance, especially the relatively high speed of the 2-pole motor, can not choose the basic group;For motors with a power frequency of 10 poles and above, it is recommended to choose the basic group of bearings. For the selection of synchronous and variable frequency motor bearings, it can be selected according to their main working speed.
Second, the shaft current is a common problem in motor products, especially high-voltage motors and frequency conversion motors, which is more harmful to the bearing system of the motor, so it is recommended that manufacturers take necessary and effective axial current avoidance measures. It is recommended to use insulated bearings for small size products. The relatively large size of the motor adopts the technical measures of bearing chamber or shaft diameter insulation, as well as grounding carbon brushes.
Third, for the selection of heavy-duty motor bearings, it is necessary to pay attention to the configuration of shaft extension bearings, select cylindrical roller bearings that can withstand large radial impact loads, and configure sliding bearings if necessary. The rationality of the choice between the free end and the fixed end has been discussed in several tweets and will not be repeated here.