The reason for the noise generated by deep groove ball bearings is quite complex, one of which is the wear of the mating surfaces of the inner and outer rings of the bearing. Due to this wear, the fit between the bearings and the housing, as well as between the bearings and the shaft, is disrupted, resulting in the axis deviating from its correct position and producing abnormal noises during high-speed movement of the shaft. When the bearing is fatigued, the surface metal peeling off can also increase the radial clearance of the bearing and produce abnormal noise. In addition, insufficient lubrication of bearings, dry friction, and bearing breakage can all produce abnormal noises. After bearing wear and looseness, the cage becomes loose and damaged, which can also produce abnormal noises.
In daily life, bearings need to be used with caution. Let's take a look at the nine things we need to pay attention to.
1. The riveting parts in the harvester, such as the moving blade assembly and rivets, are generally made by cold extrusion and should not be heated during riveting, as heating can reduce the material strength. After riveting, a forming punch should be used to strengthen the firmness of the blade and the tool holder.
2. Wearable parts, especially shafts, compression plates, sleeves, and shims, should not be replaced with extra grease during maintenance. Prolonged use of worn parts can shorten the lifespan of other machinery.
3. When repairing various types of shafts without a balancing machine, a thrust bearing can be installed on one end of the shaft, clamped on the three claws of the lathe, and the other end can be pointed. If the lathe is short, the center frame can be used to clamp the bearing installed on the other end of the shaft until it is balanced. But when balancing, tighten with screws and try not to use welding for balancing.
4. In maintenance, due to the variety of bearing material models and difficulty in purchasing, waste shafts can be used for processing. Currently, most shafts in China are made of 45 # carbon bonded steel. If quenching and tempering are required, in poor conditions, oxygen or earth furnace can be used to heat the required parts to red, medium, and black, and place them in salt water, depending on the demand.
5. When processing sleeve parts, try to pull the oil groove in the sleeve hole as much as possible. It is very difficult to add oil to certain parts of the harvester. Butter and heavy engine oil can be used in areas that are difficult to add oil, except for nylon sleeves. Do not use cast iron, copper, or aluminum instead of nylon sleeves, as nylon sleeves can withstand certain impacts without deformation.
6. The repair of the key and keyway on the pulley and shaft should ensure that the size remains unchanged in advance. Do not increase the size of the key, otherwise it will affect the strength of the shaft. The keyway on the shaft can be repaired with welding filler and milled in the opposite direction of the old key. The keyway on the pulley can be fitted with a sleeve (transition fit). After being fitted, use countersunk screws to thread and tighten the key in the sleeve seam.
7. The maintenance of the hydraulic part of the harvester involves removing the distributor and flow reducing valve, and using an air pump to pressurize the various pipe fittings. The hydraulic oil should be filtered and discharged during secondary loading. The maintenance of the hydraulic assembly mainly involves sealing components, which should be replaced with new ones after removal. This damage will further exacerbate vibration, noise, and heating, leading to bearing damage.