In fact, when considering the limit speed of IKO bearing, not only the type of IKO bearing, but also the components of the bearing, such as the material, form, design and process factors of cage, but also the sliding friction inside the bearing, the storage and maintenance of lubricant, the stability of rolling element operation, etc, Sometimes it will become the key to whether the bearing can reach the limit speed. The life requirements and reliability requirements of the bearing are considered uniformly. Generally, the reliability coefficient is 90%, which means that 90% of the IKO bearings operating under the same working conditions still maintain normal state when reaching the predetermined working life L10.
If you want to obtain higher reliability, such as 96%, you must reduce the required life of IKO bearing, for example, you must reduce the life of L10 to L4. Generally speaking, for the main shaft bearing, the high requirement is that it has the same or slightly higher service life as the whole machine, and the low requirement is that the service life is longer than the overhaul period of the main shaft components. In fact, the comprehensive consideration scheme that can meet the performance requirements of the main engine without causing the main shaft system to be too large and cost-effective is mostly adopted. For most machines, There are quite successful precedents for reference.
As well as wear, lubrication failure and fretting abrasion, shall also be considered in the type selection calculation. Among them, the wear life must be checked, and other failure forms must also be considered if involved. Note that the expected fatigue life and wear life of IKO bearing are not only related to lubrication, but also directly related to the cleanliness of bearing installation position, bearing itself and lubricant used for IKO bearing, but also related to the form and effect of sealing. The rated life of IKO bearing must be adapted to the conditions of lubrication, cleanliness and sealing provided, Improving these conditions can also improve the actual service life of IKO bearings.
When considering the load factor, it should be noted that the service life of the bearing is more sensitive to the load than the speed. Therefore, for multi-stage transmission shaft, if possible, the larger deceleration should be placed in the later stage; For the main shaft bearing, if possible, properly adjust the distance between the external load action point and the bearing fulcrum, strive to reduce the load of the main shaft IKO bearing, and strive to ensure that the load transmitted to the main shaft IKO bearing is stable and avoid impact and vibration, which requires that the shape and position accuracy of the bearing installation part are high enough, and the clearance and fit of IKO bearing are selected correctly, The installation accuracy of the bearing is good.