For each bearing, there is its own limit rotational speed, the speed of the wide slot take up bearings is mainly restricted by the temperature rise caused by the friction heat inside the bearing, when the rotational speed exceeds a certain limit, the bearing will not be able to continue to rotate due to burns and so on, or even make the bearing jammed.
Therefore, when we rotate the right type of bearing according to the rotational speed of the bearing, then we need to find out what are the requirements for rotational speed selection of bearings. In some applications, other factors are more important than the limiting speed. Such as: low speed, reciprocating oscillation, etc..
The limiting speed of a bearing is the threshold value at which it can rotate continuously without generating frictional heat that causes burns. Therefore, the limiting speed of a bearing depends on various factors such as the type, size and accuracy of the bearing as well as the method of lubrication, the quality and quantity of the lubricant, the material and type of cage, and the loading conditions.
The limit speed given by the wide slot take up bearings manufacturer generally refers to the maximum speed that can be achieved under the agreed conditions: for example, bearing tolerance is 0 level; bearing clearance is 0 group; bearing load is 10% of the rated load; lubrication and cooling conditions are normal; centripetal bearings only bear radial load, thrust bearings only bear axial load; outer ring temperature does not exceed 100 ℃, etc..
The range of speeds required for the application helps determine what type of bearing to use. Most of the bearing manufacturer’s catalogs provide their products limit speed value, practice has proved that in less than 90% of the limit speed of the state work is better.
Selection of wide slot take up bearings type by rotational speed
- Ball bearings have higher limiting speed and rotary accuracy than roller bearings, so ball bearings should be preferred in high speed.
- In the same conditions of the inner diameter, the smaller the outer diameter, the smaller the rolling body, the operation of the rolling body added to the foreign raceway on the centrifugal inertia force is also smaller, and thus also suitable for work at higher speeds. Therefore, in high speed, it is appropriate to use the same diameter series in the smaller diameter bearings. If the bearing with a smaller diameter and the bearing capacity does not meet the requirements, and then installed the same wide slot take up bearings, or consider using a wide range of bearings.
- The cage material and structure of the bearing speed has a great influence.
Solid keep frame than stamping keep frame allows some higher speed, bronze entity keep frame allows higher speed.
Generally higher speed work occasions, it is appropriate to use deep groove ball bearings, angular contact bearings, cylindrical roller bearings;
In the lower speed work occasions, can choose tapered roller bearings.
Tapered roller bearings limit speed, generally about 65% of the deep groove ball bearings, cylindrical roller bearings 70%, angular contact ball bearings 60%. Thrust ball bearings have a low limiting speed and can only be used in low speed applications.
Factors affecting wide slot take up bearings speed
Factors affecting the limiting speed of the bearing include the size of the applied load; the direction of the force; the type of lubricant, the amount of lubricant; the manufacturing accuracy of the bearing, i.e., the tolerance level of the bearing and the size of the clearance of the bearing.
In addition, the lubricant according to its type and grade of different, may also be better than other performance but not for high-speed rotation.
Wide slot take up bearings limit speed of the high and low factors are related to the type of bearing, load, precision, size, lubrication, clearance, cage and cooling conditions. However, the most important factor is the operating temperature or lubricant allowed by the bearing material.
Selection methods for rolling bearing fits
Correct selection of bearing fit, to ensure the normal operation of the machine, improve the service life of the bearing and the full utilization of the bearing capacity of the bearing has a great relationship.
- Whether the collar is rotating. When the inner or outer ring wide slot take up bearings work for the rotating circle, should use a slightly tight fit, the size of the surplus should be so that the surface in the working load does not occur “creep”, because once the creep occurs, with the surface to be worn out, resulting in sliding, the higher the speed of the ring, the more serious the wear and tear. Bearing work, if the inner ring or outer ring for the non-rotating ring, in order to disassemble and adjust the convenience, it is appropriate to use a loose fit.
- Load type. Bear a local load of the collar should be selected looser transition fit or clearance smaller fit, in order to let the collar raceway friction torque drive the collar transposition, so that the collar force uniformity, prolonging the service life of the bearings.