The axis of a horizontal motor is parallel to the ground and the axis of a vertical motor is perpendicular to the ground. Compared with horizontal motors, the bearing system of vertical motors has its own requirements, the most intuitive requirement being that the bearings must be able to withstand large axial forces.

Horizontal motor fixed bearings for deep groove ball bearings, can withstand radial load, can also withstand a certain amount of axial load; but for vertical motors, due to its axial force is larger, and deep groove ball bearings can not withstand a large axial load, so vertical motors are mostly used in angular contact ball bearings. Whether single row or double row, angular contact ball bearings have higher axial load capacity and speed.

Deep groove ball bearings are generally used in vertical motors with specifications of H280 and below, while angular contact ball bearings are used in motors with specifications of H315 and above. High precision and high speed bearings generally have a contact angle of 15 degrees. Under the action of axial force, the contact angle increases.

Load carrying capacity is determined by the contact angle, the larger the contact angle, the greater the ability to withstand the axial load, and can limit the axial displacement of the shaft or shell in a certain direction.

For vertical motors with angular contact ball bearings, the angular contact ball bearings are usually mounted at the non-axially extending end to ensure that the axially extending end bearings support a sufficiently large radial force demand. However, angular contact ball bearing mountings are subject to strict orientation requirements to ensure that the bearings can support axial forces in the downward direction, i.e. in the same direction as the rotor gravity.

When the motor extends axially upward, the angular contact ball bearings are mounted on the non-axially extending ends to meet the axial force while also ensuring the end cap assembly process; when the motor extends axially downward, the same angular contact ball bearings are mounted on the non-axially extending ends, but the end cap ends need to be assembled with corresponding measurements taken to ensure that the bearings are not damaged.

Simply put, angular contact ball bearings "hang" or "lift" the motor rotor. If the angular contact ball bearings are located in the upper part, it must be ensured that the bearings "catch" the rotor; if the angular contact ball bearings are located in the lower part, it must be ensured that the bearings can "lift" the rotor. But to meet the above functional requirements, must also consider the end cover assembly process, that is, the end cover assembly of the external force and the bearing can withstand the same axial force (angular contact of the inner ring of the ball bearing and the outer ring can only withstand the direction of the opposite direction of the axial force), otherwise it will be pushed out of the bearing frame.

As a fixed bearing, the axial adjustment of the bearing outer ring and the bearing inner and outer cover can not leave any gap to ensure that the bearing is in a good state of adjustment; in addition, the adjustment of the inner ring and the shaft needs to be adjusted with interference, while the adjustment of the bearing outer ring and the bearing chamber for the adjustment of a smaller gap is more reasonable.