In order to maintain the original performance of the bearing in good condition for as long as possible, it is necessary to maintain and overhaul the bearing in order to prevent accidents, ensure the reliability of operation, and improve the productivity and economy.The best maintenance of the corresponding mechanical operating conditions of the operating standards, regular.These include monitoring of operating conditions, replenishing or replacing lubricants, and inspection of periodic disassembly.As the operation of the maintenance matters, there is the rotation of the bearing sound, vibration, temperature, lubricant state, and so on.
Bearing cleaning: When removing the bearing for overhaul, the appearance of the bearing should be recorded first, the residual lubricant should be confirmed, and the bearing should be washed after the lubricant used for sampling inspection.As a cleaning agent, gasoline and kerosene are commonly used.
Clean the disassembled bearings, divide the coarse cleaning and fine cleaning, respectively, put them in the container, first put the metal mesh bottom, so that the bearings do not directly contact with the container dirty.If the bearing is rotated with dirt during rough cleaning, the rolling surface of the bearing will be damaged. Attention should be paid.In coarse cleaning oil, use a brush to remove grease and stickiness, after roughly clean, transfer to fine washing.
Fine washing is to clean the bearings carefully while rotating in the cleaning oil.Also, keep the oil clean.
Bearing maintenance and judgment: In order to determine whether the removed bearing is serviceable, check the bearing after it is cleaned.Check the state of raceway surface, rolling surface and mating surface, wear condition of cage, increase of bearing clearance and damage of irrelevant dimension accuracy.For non-separable small ball bearings, hold the inner ring level with one hand and rotate the outer ring to make sure it is smooth.
Separate bearings such as tapered roller bearings can be checked on the raceway surface of rolling body and outer ring respectively.
Since large bearings cannot be rotated by hand, pay attention to check the appearance of rolling body, raceway surface, retainer, and flank surface, etc. The more important the bearing is, the more careful inspection is required.
Purpose of bearing lubrication:
The lubrication purpose of the rolling bearing is to reduce the internal friction and friction of the bearing and prevent burning and adhesion. Its lubrication effect is as follows.
(1) Reduce friction and friction damage.
The contact part of the bearing ring, rolling body and retainer can prevent metal contact and reduce friction and wear.
(2) Prolong fatigue life.
The rolling fatigue life of the bearing is prolonged in rotation when the rolling contact surface is well lubricated.On the contrary, the oil viscosity is low, the oil film thickness is not good, it is shortened.
(3) Discharge friction heat and cooling.
Circulating oil can be used to remove heat from friction, or heat from the outside, and cool down.Prevent bearings from overheating and lubricating oil from aging.
It also has the effect of preventing foreign matter from intruding into the bearing, or preventing rust and corrosion.Lubrication method:
Lubrication methods of bearings are divided into grease lubrication and oil lubrication.In order to make the bearing function well, first of all, to choose suitable for the use of conditions, the purpose of lubrication.If only lubrication is considered, lubricity of oil lubrication is dominant.However, grease lubrication has the advantage of simplifying the structure around the bearing and comparing the advantages and disadvantages of grease lubrication and oil lubrication.
Whether the bearing is installed correctly affects the accuracy, life and performance.Therefore, the design and assembly department should fully study the bearing installation.It is expected that the installation will follow the operating standard.The operating standard items are usually as follows:
(1) Clean bearings and bearing related parts;
(2) Check the size and finishing of related parts;
(4) Inspection after the bearing is installed;
(5) Provide lubricant.
It is hoped that the bearing packing will be opened shortly before installation.General grease lubrication, do not clean, directly filled with grease.Lubricating oil lubrication, general also do not have to clean, but, the instrument or high-speed bearings, to clean with clean oil, remove coated on the bearing antirust agent.Remove the antirust agent of the bearing, easy to rust, so can not be placed regardless.Furthermore, bearings sealed in grease are not cleaned and used directly.
Bearing installation method, depending on the bearing structure, fit, conditions vary, generally, because most of the shaft rotation, so the inner ring needs interference fit.Cylindrical bore bearings, multi-purpose press or multi-purpose heat loading.In the case of taper holes, install directly on the taper shaft, or with sleeve installation.
When installing to the housing, there are generally many clearance fits, and the outer ring has interference, which is usually pressed in by a press, or there is also a cold-shrink fit method for installation after cooling.When dry ice is used as coolant, the moisture in the air will condense on the surface of the bearing in conjunction with the installation.Therefore, appropriate anti-rust measures are needed.