Tapered roller bearings are separable. The inner and outer rings can be separated. Therefore, during installation, the inner ring cage rolling element components can be separately press-fitted on the shaft, and the outer ring can be separately installed into the bearing housing hole. When using the sleeve to press-fit, it should be noted that the end of the sleeve must be placed on the end surface of the outer ring and not placed on the inclined end. On the raceway surface.
Most tapered roller bearings are used in pairs. During installation, three aspects should be paid attention to. Choose installation and adjust the axial clearance for debugging and temperature detection.
Choose the right installation
The outer ring of the tapered roller bearing and the housing hole of the bearing seat should not be used at the same time as the inner ring and the journal. It is not suitable to be used too tightly. When installing the nut, it should be adjusted to produce more flexible axial displacement. Because the tapered roller bearing uses interference with the change of the bearing contact angle, it is easy to cause the high temperature rise caused by the uneven bearing load distribution. Therefore, this type of bearing inner and outer ring and the shaft journal and the housing hole of the bearing seat are generally pushed into the journal with both hands and thumbs, and the housing hole is the best hole.
Adjust the axial clearance
The thrust gap used to install tapered roller bearings can be used to adjust the nut on the journal, adjust the washer and the thread of the bearing seat or with a pre-compressed spring. Axial clearance is the size of the bearing during installation. In this arrangement, the distance between the bearing, the shaft and the bearing can be determined according to the working conditions. When adjusting the clearance for high load, high-speed tapered roller bearings must adjust the effect of temperature rise on the axial clearance. The increase in clearance caused by the temperature rise, that is, the axial clearance should be adjusted to a greater degree. For low-speed and vibrating bearings, clearance-free installation or pre-installation should be adopted. The purpose is to make the tapered roller bearing roller and raceway produce a good contact load evenly distributed, and prevent the drum and the drum from being damaged by vibration. Use a dial gauge to check and adjust the size of the axial clearance. The method is to fix the first micrometer on the body or the housing so that the glossy surface of the micrometer contacts the shaft against the shaft. The maximum allowable amount of the axial needle is the axial clearance value.
Perform commissioning and temperature testing
In order to make the rollers of the tapered roller bearing have good contact with the raceway and obtain the appropriate axial clearance, the sub-bearing should be tested and tested after each clearance adjustment. The method is the first low speed operation for 2-8 minutes, then the speed test for 2 hours, and then step by step to high speed. Each level of speed test run shall not be less than 30 minutes, the heating rate shall not exceed 5℃/hour, and the final stable temperature shall not exceed 70℃. In addition, when installing and adjusting tapered roller bearings, you should also pay attention to the need to make tapered rollers and the large ribs of the ring have good contact.
One, install the bearing
The bearing must be installed in a dry and clean environment. Before installation, check the mating surface of the shaft and the housing, the end surface of the shoulder, the quality of the groove and the connecting surface. By having a surface that must be carefully cleaned and removed to remove burrs. In addition to clean sand, the unprocessed surface must also be removed. The bearings should be installed before using gasoline or kerosene for the first time. After use, they should be clean and dry and ensure good lubrication of the shaft. Generally, grease can also be used for lubricating oil. When using grease lubrication, use grease with excellent performance such as no impurities, anti-oxidation, anti-fouling, extreme pressure and so on. The grease filling capacity is 30%-60% of the volume of the bearing and bearing box should not be too much. Double-row tapered roller bearings and water pump sealed structure bearings have been filled with grease. Users can go straight and then do not use it for cleaning. The bearing must be equipped with equal pressure on the circumference of the end face of the ring. Use a hammer and other tools to directly hit the bearing end to avoid damage to the bearing. In this case, if the interference is small, press the sleeve on the sleeve at room temperature. Use the sleeve to press the sleeve through the sleeve. Such as in the case of a large number of installations, hydraulic presses can be used. In the case of press fit, the end surface of the outer ring and the inner surface of the housing should be compressed to allow no clearance between the end surface of the fixed ring and the end surface of the shaft shoulder. When the oil bath heating or the sensor heating method is installed with the heating temperature, the interference fan can be used. The ambient temperature is 80℃-100℃, and the maximum does not exceed 120℃. Tighten the shaft with a nut or other suitable method in order to prevent the bearing from cooling down in the direction of the journal direction and the gap between the shoulders. The final clearance should be adjusted for the installation of single row tapered roller bearings. The value of customs clearance should be based on the use of different workers and determined by the specific amount of interference. If necessary, it should be tested to determine. The double-row tapered roller bearing and the water pump shaft bearing have been installed with an adjusted clearance before leaving the factory, and no adjustment is required. After the bearing is installed, the rotation test of the rotating shaft or bearing seat should be carried out first. Force no-load operation, low-speed operation, and then gradually increase the speed and load, measure and detect noise, vibration and temperature rise, and stop operation and check if abnormalities are found. The running test before delivery is normal.
Use bearing environment
Selecting the size according to the used parts, operating conditions and environmental conditions, accuracy and appropriate bearings are the prerequisites for consistent bearing life and feasibility.
1. Part of use
Tapered roller bearings are suitable for radial and axial loads of radial loads. Bearings are mainly used for driving moving parts such as front and rear wheel hubs, driving bevel gears, differentials, and reducers.
2. Allowable speed
Under correct installation and good lubrication environment, the bearing speed limit is allowed to be 0.3-0.5 times. Generally, the limit speed is the most suitable under the normal condition of 0.2 times.
3. Allowable tilt angle
Tapered roller bearings generally do not allow the shaft to tilt relative to the housing hole, and the maximum is not more than 2'.
4. Allowable temperature
Under normal working conditions, the normal load and lubricant have high temperature resistance and sufficient lubricating effect, allowing it to work at an ambient temperature of -30°C to 150°C.