When installing double row tapered roller bearings, special attention should be paid to environmental cleanliness, fitting accuracy, installation methods, clearance adjustment, and lubrication maintenance. Specific precautions are as follows:
1. Installation environment and cleaning requirements
Environmental requirements: Installation must be carried out in a dry and clean environment to avoid impurities such as dust and metal debris from entering the bearing.
Cleaning treatment: Before installation, carefully inspect the mating surface of the shaft and housing, the end face of the shoulder, the groove, and the processing quality of the connecting surface.
. All mating surfaces must be carefully cleaned and deburred, and the unprocessed surfaces of castings must be cleaned of molding sand. Before installing bearings, they should be cleaned with gasoline or kerosene and dried before use.2. Match accuracy and size inspection
Match size: Ensure that the journal and bearing inner ring have an interference fit, and the bearing seat hole and outer ring have a clearance fit.
. The interference fit should be determined based on the bearing size and operating conditions, usually ranging from 0.001-0.003 times the diameter of the shaft neck.Size inspection: Check the size of the bearing seat hole to ensure it matches the outer diameter of the bearing, avoiding looseness (causing "outer ring") or tightness (increasing installation difficulty).
.III. Installation Method and Tool Selection
Installation Method:
Room Temperature Installation: With a small interference fit, the bearing ring end face can be pressed with a sleeve at room temperature, and the sleeve can be hammered with a hammer to evenly press the ring through the sleeve.
. When installing in large quantities, hydraulic presses can be used. Heating installation: When the interference fit is large, oil bath heating or sensor heating bearing methods can be used for installation. The heating temperature range is 80 ℃ -100 ℃, and the maximum temperature cannot exceed 120 ℃. After heating, it is necessary to install immediately and tighten the bearing with nuts or other appropriate methods to prevent the bearing from shrinking in the width direction after cooling, which may cause a gap between the ring and the shaft shoulder.Tool selection: Special tools such as sleeves, hydraulic presses, etc. must be used during installation to avoid directly tapping the bearing end face and damaging the bearing.
.IV. Clearance Adjustment and Testing
Clearance Adjustment: Double row tapered roller bearings have already adjusted their clearance at the factory, and usually do not need to be adjusted again during installation.
. But if the clearance needs to be adjusted, it can be done on the shaft neck by adjusting the nut, washer, bearing seat hole internal thread, or using a pre tensioning spring. The clearance value should be determined specifically based on different operating conditions and the size of the interference fit, and if necessary, experiments should be conducted to determine it.Clearance detection: The size of axial clearance should be accurately detected using a dial gauge to ensure that the clearance value is within a reasonable range.
.V. Lubrication and Maintenance
Lubrication Requirements: Good lubrication should be ensured before bearing installation, generally using grease lubrication or oil lubrication.
. When using grease lubrication, lubricating grease with superior properties such as impurity free, antioxidant, rust proof, and extreme pressure should be selected. The filling amount of lubricating grease should be 30% -60% of the volume of the bearing and bearing housing, and should not be too much.Maintenance: After installation, it is necessary to regularly check the lubrication of the bearings and promptly replenish or replace the lubricating grease.
. At the same time, it is necessary to regularly check the operation of the bearings. If any abnormal noise, vibration, or high temperature rise is found, the machine should be stopped in a timely manner for inspection and handling.