How to improve IKO bearing reliability measures?

This paper analyzes the function and working condition of IKO bearing in hydraulic torque converter of bulldozer, and puts forward special requirements on the design, manufacture, selection and installation process of bearing, which effectively improves the reliability and service life of the bearing.

Hydraulic torque converter;  IKO bearings;  reliability  

How to improve the reliability of IKO bearings installed on TY320 torque converter is a key technical issue to prolong the service life of TY320 torque converter.  TY320 type hydraulic torque converter is installed on the TY320 bulldozers are connected to the engine and gearbox transmission device, must be used for thespecific structure of bulldozer and working condition, for in the use of the damage of bearing in carries on the analysis and research, in the design, manufacture, selection and installation of bearing technology and other aspects put forward special requirements,  Only in this way can the reliability of IKO bearing be effectively improved and the service life of TY320 hydraulic torque converter be prolonged.

The role and working conditions of bearings  

The IKO bearing on TY320 hydraulic torque converter is an angular contact ball bearing installed back-to-back in pairs (bearing rear code plus /DB).  The inner ring of the bearing is installed on the turbine hub, and the outer ring is installed on the pump wheel contact plate. An important role of the bearing is axial positioning, that is, to ensure that there is a certain axial clearance between the pump wheel, turbine and regulating wheel of the hydraulic torque converter, so that the three wheels of the hydraulic torque converter do not collide and friction when working.  If the bearings are damaged, there will be friction collision 

between the three wheels, and the hydraulic torque converter will not work properly.

The working temperature of this pair of bearings in the hydraulic torque converter is about 100℃.  The inner and outer rings rotate with the turbine and pump wheel respectively, and the relative speed of the inner and outer rings changes frequently in a wide range.  The working condition of bulldozer is earth-moving - backward - walking - earth-moving, so the axial load of bearing is also frequently changed.  Especially in the earth pushing encountered large stones or roots, load suddenly increased, pump wheel with the engine speed unchanged, turbine speed rapidly decreased, torque rapidly increased, bearing inside and outside 

the ring of the relative speed will suddenly improve, and at the same time by a lot of axial impact load.

bearing damage and cause analysis  

According to the inspection of several cases of bearing damage, it is found that in this pair of bearings installed back-to-back, as shown in FIG. 1, the left bearing is seriously damaged, the steel plate stamping cage is deformed and fractured, the ball surface is worn and deformed, and the shoulder of the inner and outer bearing raceway subjected to axial impact is extruded and flattened. 

This situation shows that the bearing is frequently subjected to a large unilateral axial impact load as shown in Figure 1, that is, the bulldozer is often overloaded.  The right bearing is not damaged.  This indicates that the preload amount of pairwise mounting bearings is inappropriate. In addition, check the lubricating oil containing more impurities, which from the ball and raceway surface there are many pitting phenomenon also reflects the oil is not clean. This shows that the lubricating oil filter maintenance 

is not in place.