How to choose bearings for vertical motors?

Vertical motors are a common installation in industrial motors, and the electrical difference is not much compared to horizontal motors, but there are some differences in the structure.

How to choose bearings for vertical motors:

In the selection of bearings, vertical motors and horizontal motors also have some special attention.

Bearing load

For locating end bearings, the rotor weight of a vertical motor is its axial load. When there is no other external radial load, the radial load from the air gap deviation of the motor becomes the radial load of the bearing.

For non-locating end bearings, it is important to avoid a situation where the load they carry is less than the minimum load required for the bearing.

Bearing configuration

Locating end bearings need to be selected to withstand axial loads. It is worth noting that this axial load will be greater than that of a horizontal motor, even if there is no external load.

Usually, the types of bearings that can be used as locating ends commonly used in vertical motors are:

deep groove ball bearings, angular contact ball bearings, spherical roller bearings, tapered roller bearings, spherical roller thrust bearings, etc. In large motors, tapered roller bearings need to be calibrated for the elastic deformation of their bearing chambers under thrust when subjected to large thrusts. Meanwhile, in vertical motors, the matching relationship between the locating end, non-locating end and shaft extension and non-shaft extension end should be determined according to some maintenance conditions, etc.

Lubrication and supplementary lubrication:

In a vertical motor, the grease flows to one side by gravity, making the bearing susceptible to poor lubrication. According to the general lubrication recommendation principle, most of the bearings of vertical motors will choose a grease with slightly higher consistency, such as No. 3 grease. At the same time, the replenishment lubrication time interval needs to be shortened by half than that of horizontal motors.

Considering the gravity factor

Grease needs to enter from the top end of the bearing chamber and exit from the bottom end. This is to facilitate the newly added grease to enter the bearing interior well.

Testing aspect

Since the bearings are selected according to the working conditions of vertical motors, they also need to be tested in a vertical way during testing. Otherwise, the light bearing test vibration and noise and the actual working conditions do not match, and the heavy bearing will be burned, especially when the single row angular contact ball bearing as the positioning end.


Storage and transportation process, should make vertical motor in accordance with the work mode vertical transportation. For the internal use of deep groove ball bearing configuration of small ordinary vertical motors, storage and transportation methods do not require special consideration.
However, if the positioning end of the motor uses a single row angular contact ball bearing, then attention should be paid to fix the shaft in the transportation process to prevent the bearing from disconnecting, thus causing damage.

Shandong Wanyu Bearing Co., Ltd. is the main agent of SKF bearings, FAG bearings, NSK bearings, TIMKEN bearings, KOYO bearings and various bearing lubricants and greases. Mine and other well-known manufacturers and bearing distributors provide products and technical support