The function of IKO bearing coordination is to make the stationary ring and rotating ring of needle roller bearing consolidate with the stationary part (usually bearing seat) and rotating part (usually shaft) of the installation part respectively,
so as to realize the basic task of transmitting load in the rotating state and limiting the position of the motion system relative to the stationary system.
On the shaft and in the bearing seat, the needle roller bearing is required to fix its position in three directions: radial, axial and tangent directions. Radial and tangential positioning is realized by tight fit of bearing ring,
and tight fit is adopted for axial positioning only in a few cases; Generally, axial limit parts, such as end caps and retaining rings, are used to limit the axial position within the clearance range.
The following four points should be paid attention to when selecting the fit:
(1) The circumferential surface of bearing ring shall have good support and uniform stress to reduce deformation and give full play to the bearing capacity of IKO bearing.
(2) The ferrule cannot slide along the tangent direction in its mating surface, otherwise the mating surface will be damaged.
(3) The free end bearing must be able to adapt to the length change of the shaft and bearing seat hole, that is, it must have the ability to adapt to the swimming of the axial position within a certain range.
(4) Attention must be paid to make the installation and disassembly of needle roller bearing simple, labor-saving, time-saving and expenditure saving.
When working under high pressure, in addition to small penetration, it should also have high oil film strength and extreme pressure performance. When selecting grease according to environmental conditions, calcium based grease is not easy to dissolve in water and is suitable for dry and less water environment.
The commonly used greases for IKO bearings include calcium base grease, sodium base grease, calcium sodium base grease, lithium base grease, aluminum base grease and molybdenum disulfide grease.
The amount of grease filled in the needle roller bearing is 1 / 2-1 / 3 of the internal space of the bearing. At high speed, it should be reduced to 1 / 3. Excessive grease will increase the temperature rise.
The temperature of the bearing can be inferred from the temperature outside the bearing chamber. It is more appropriate if the oil hole can be used to directly measure the temperature of the outer ring of the
Thin-walled bearing. Usually, the temperature of the bearing starts to rise slowly with the operation of the bearing, and reaches a stable state after 1-2 hours. The normal temperature of needle roller bearing varies with the heat capacity, heat dissipation, speed and load of the machine.
If the lubrication and installation parts are appropriate, the temperature of IKO bearing will rise sharply and abnormal high temperature will occur. At this time, the operation must be stopped and necessary preventive measures must be taken.
Bearing is a kind of precision mechanical support element. Bearing users deeply hope that the bearing installed on the main engine will not be damaged and maintain its dynamic performance within the predetermined service life,
but the objective facts are sometimes not satisfactory. Sudden bearing failure accidents will cause great losses to users. Through a large number of bearing failure analysis and research, it is shown that the short life or premature loss of accuracy of needle roller bearing is caused by material defects or improper manufacturing,
but to a considerable extent, it is due to the failure to install and maintain in strict accordance with the requirements of bearing use, Or the abnormal damage of IKO bearing is caused by improper bearing selection or the actual load exceeds the rated load of Thin-walled bearing itself.
The cracking and spalling of the bearing is caused by the fatigue damage of the contact surface of the bearing under the action of periodic load. Therefore, in order to improve the service life of the needle roller bearing, the bearing steel must have high contact fatigue strength.
Hardness is one of the important qualities of IKO bearing, which has a direct impact on contact fatigue strength, wear resistance and elastic limit. The hardness of Thin-walled bearing steel in service should generally reach HRC61 ~ 65, so that the needle roller bearing can obtain high contact fatigue strength and wear resistance.