A ball bearing and a column bearing should be used as far as possible at both ends of the horizontal motor. At present, two ball bearings are mostly used in domestic 2-pole small and medium-sized motors, although some manufacturers have adjusted the tolerance of the inner diameter of bearing chamber to the direction of clearance fit, in order to alleviate the disadvantage of ball extrusion after bearing heating. However, because the expansion coefficient of the bearing jacket is larger than that of the cast iron part that bears the bearing chamber, the end cover or bearing sleeve, and the temperature at the bearing jacket is also higher, the bearing jacket can slide a little bit along the axial direction in the bearing chamber at room temperature, but the bearing may not be able to string when it is heated, that is to say, the use of two ball shafts Bearing life is short and easy to heat the main reasons.

If you choose a ball bearing and a column bearing, the above problems can be avoided. In the same electric machinery factory, the high voltage motor with 2 poles in the seat number of H 560 is changed from 2 ball bearings to 1 ball bearing and 1 column bearing, and the operation effect is very good in the later stage. Except for the replacement of bearings according to the conventional maintenance cycle, there has never been a failure in normal operation. And the temperature measured at the bearing is only 20 ℃. This is the first time that the two pole motor has been changed into a ball bearing and a column bearing for the first time in China, which has been gradually popularized in explosion-proof motor.

In order to solve the problem of extreme speed heating and noise after replacing ball bearing with column bearing, a light series column bearing can be adopted and placed at the end of external fan, and the cooling condition is good. At the same time, the bearing noise can also be flooded by fan noise. If the power of the two-pole motor is large, and the light series column bearings are unable to meet the requirements of the limit speed, the bearing grease can also be changed to dilute oil.