This article describes the specification requirements and precautions for bearing installation, and expands on the installation and use of various types of bearings.
Keywords: bearing; installation; requirements
Bearing installation specifications
Bearing installation environment is very important. Bearings are important parts of industrial machinery and equipment. The quality of installation plays a vital role in the use of bearings. Therefore, we need to make some preparations before installing bearings. According to data statistics, It is known that 14% of bearing contamination is caused by improper preparation before installation, such as environmental problems.
The installation environment of the bearing is very important. It must be installed in a dry and clean environment so that the bearing can operate better.
In order to let everyone know more about the preparation work for bearing installation, I will share some matters before bearing installation based on my understanding of bearing knowledge:
1. Different installation methods are adopted according to different bearing sizes and application environments;
2. Prepare the necessary components, tools and equipment for installation;
3. Prepare all parts that need to be installed and clean them thoroughly before installation;
4. Check the size and shape accuracy of all parts that need to be installed according to the drawings.
Note: When installing the bearing, do not unpack the bearing before the preparation work is completed to avoid contamination of the bearing.
Installation and use of deep groove ball bearings
1. When installing the bearing, the force should be uniform and should not be hammered directly. For example, if the fit interference is large, the bearing should be heated in an air heating furnace or oil furnace with automatic temperature control, and the heating temperature should be strictly controlled below 120°.
2. Bearings equipped with nylon cages can operate continuously and stably for a long time at -40°-120°. The operation at 150° should not exceed 4 hours, and the short-term temperature peak should not exceed 180°.
3. The warehouse where bearings are stored should be clean, dry and not allowed to be stored in the same warehouse as chemical products. The relative humidity should not exceed 65%, and bearings are not allowed to be stored on the floor.
4. Bearings in stock should be re-cleaned every other year and packed in anti-rust packaging.
Angular contact ball bearing installation and use
1. When installing the bearing, the force should be uniform and should not be hammered directly. For example, if the fit interference is large, the bearing should be heated in an air heating furnace or oil furnace with automatic temperature control, and the heating temperature should be strictly controlled below 100°.
2. Bearings equipped with nylon cages can work continuously and stably for a long time at -40°-120°. The operation at 150° should not exceed 4 hours, and the short-term temperature peak can reach 180°.
3. The warehouse where bearings are stored should be clean, dry and not allowed to be stored in the same warehouse as chemical products. The relative humidity should not exceed 65%, and bearings are not allowed to be stored on the floor.
Installation and use of spherical roller bearings
1. The user should select the appropriate fit and the dynamic clearance of the bearing according to the usage requirements. Please correct the bearing code after unpacking.
2. Before the bearing is installed, if grease needs to be added to the bearing, the grease must be clean and appropriate.
3. During installation, it is advisable not to directly hammer the inner and outer ring end faces and rollers to avoid cracking the inner ring or the middle and small ribs. Usually the user should put the bearing in mineral oil and heat it to 90°-100° and install it on the spindle immediately. Do not use local spray burning method on bearings. When it is difficult to “hot install”, users should also use special sleeves to install them.
4. The bearing should have good sealing and dust-proof device and lubrication during use, and the oil should not be cut off.
5. The bearing warehouse should be clean and dry, without environmental pollution, the bearings should not be stacked on the ground, and the packaging should not be damaged. Bearings that have been in stock for more than one year must be re-cleaned and oiled.
Thrust spherical roller bearing installation and use
1. When installing the bearing, the bearing oil seal should be cleaned and then coated with clean high-quality lubricating oil.
2. When installing the bearing, the force should be uniform and no hammering should be allowed. If the fit interference is large, the bearing should be placed in mineral oil and heated to 90°-100° before installation immediately.
3. The warehouse where bearings are stored should be clean and tidy, with a relative humidity not exceeding 65%.
4. Bearings in stock should be re-cleaned and oiled every other year, and the oil seal packaging should be kept in good condition.
5. When using bearings, there should be good sealing and dust-proof devices, and the working conditions should be checked frequently.
Cylindrical roller bearing installation and use
1. This bearing is a separate type, and the user can adjust the clearance as needed during installation.
2. Before use, the bearings should be cleaned with gasoline or kerosene and kept well lubricated.
3. When installing the bearing, the bearing should be pressed into the component and knocking is strictly prohibited.
4. The bearing storage place should be clean and ventilated to avoid moisture. Bearings that need to be stored for a long time should be rust-proofed regularly.
Thrust ball bearing installation and use
1. When installing the bearing, the bearing seal should be removed, washed and then coated with clean high-quality lubricating oil.
2. When installing the bearing, the force should be uniform and no hammering should be allowed. If the fit interference is large, the bearing should be placed in mineral oil and heated to 90°-100° before installation immediately.
3. The warehouse where bearings are stored should be clean and tidy, with a relative humidity not exceeding 65%.
4. Bearings in stock should be re-cleaned and oiled every other year, and the oil seal packaging should be kept in good condition.
5. When using bearings, there should be good sealing and dust-proof devices, and the working conditions should be checked frequently.
Precautions before installation
1. Preparation of bearings
Since the bearings are rust-proofed and packaged, do not open the package until installation.
In addition, the anti-rust oil coated on the bearings has good lubrication properties. For general-purpose bearings or bearings filled with grease, they can be used directly without cleaning. However, for instrument bearings or bearings used for high-speed rotation, clean cleaning oil should be used to wash away the anti-rust oil. At this time, the bearings are prone to rust and should not be left for a long time.
2. Inspection of shaft and housing
Clean the bearings and housing to make sure there are no scratches or burrs left by machining. There must be no abrasives (SiC, Al2O3, etc.), molding sand, chips, etc. inside the casing.
Secondly, check whether the size, shape and processing quality of the shaft and housing are consistent with the drawings.
Before installing the bearing, apply mechanical oil to each mating surface of the inspected shaft and housing.
Bearing installation method
Bearing installation methods vary depending on bearing type and matching conditions.
Since most of the shafts rotate, the inner ring and outer ring can adopt interference fit and clearance fit respectively. When the outer ring rotates, the outer ring adopts interference fit.
The bearing installation methods when using interference fit can be mainly divided into the following types:
1. Press-in installation
Press-in installation generally uses a press, but bolts and nuts can also be used. If necessary, a hand hammer can be used for installation.
2. Hot sleeve installation
The hot-sleeving method of heating the bearing in oil to expand it and then installing it on the shaft can prevent the bearing from unnecessary external force and complete the installation work in a short time.
Heating precautions:
1. Generally, heating should not exceed 100 degrees Celsius.
2. The bearing is not allowed to contact the bottom of the oil groove.
In addition, the thermal sleeve installation can also use an induction heating device to heat the bearing and expand it before installing it on the shaft.
Bearing disassembly
Bearings need to be disassembled when performing regular inspections or replacing parts. Usually the shaft and bearing housing almost always continue to be used, and the bearings also tend to continue to be used. Therefore, the structural design must take into account that when disassembling the bearing, the bearing, shaft, bearing box and other parts will not be damaged, and appropriate disassembly tools must also be prepared. When disassembling a statically fitted ferrule, only tensile force can be applied to the ferrule, and the ferrule must not be pulled through the rolling elements.
Key points to note when installing split bearings
1. Installation of bearing seat: When installing split bearings, bearing seats and bearing caps, the back side of the bearing bushing should be in close contact with the hole of the bearing box. If the platform requirements are not met, the bearing housing bore should be used as a benchmark. The back of the bearing bushing should be scraped and the cracked surface of the bearing should be 0.05-0.1mm higher than the cracked surface of the bearing seat.
2. The contact area between the rear part of the bearing and the bearing seat: the upper brick is not less than 40, and the lower brick is not less than 50. The contact area is required to be uniform and there is no gap between the two blocks. Bottom and sides of lower tiles. When bearing bushings are subjected to high pressure, rapid wear can result. Too few contact points between the bearing pad and the bearing seat will cause increased wear, deformation and cracking of the bearing pad.
3. Installation of bearings and journals: When installing bearings, attention must be paid to the contact angle and contact point between the bushing and journal. The central angle corresponding to the contact surface between the bearing pad and journal is called the contact angle. If the angle is too large, it will affect the formation of the lubricating oil film, destroy the lubrication effect, and cause the bearing bush to wear quickly.
4. Please pay attention to the adjustment of the bearing clearance during installation, which can be optimized according to the equipment load, speed and oil viscosity.
The structure of the split bearing is very special and it is widely used. The most important thing is that it is easy to install, so it can replace the use of traditional bearings and is easier to detect than conventional bearings.
