Bearings vary in type, type and size. In order to make the Problems Needing mechanical equipment play the expected performance, it is very important to select the appropriate SKF Bearing.
A lot of analysis is needed for the selection of bearings, because Problems Needing there is no selection of bearings with special specifications from various angles, research and evaluation procedures, but they are usually in the following order:
(1) Master the service conditions of mechanical devices and SKF bearings
(2) Clear requirements for bearings
(3) Type of selected bearing
(4) Selected bearing configuration
(5) Selection of bearing size
(6) Select bearing size
(7) Installation method of selected bearing
Service and environmental conditions bearing
On the premise of correctly grasping the SKF Bearing area Problems Needing used under the service conditions and environmental conditions of mechanical equipment, select the appropriate bearing. Who needs the following data and information:
(1) Function and structure of mechanical equipment
(2) Field use of SKF bearings
(3) Bearing load (size, direction)
(4) Rotation speed
(5) Vibration, shock
(6) Bearing temperature (ambient temperature, temperature rise)
(7) Ambient atmosphere (corrosive, clean, lubricated)
Bearing configuration options
Usually, it is supported radially and axially by two shaft bearings, and this time, the square is called the fixed side SKF Bearing, which Problems Needing bears the relative axial displacement of the fixed shaft and bearing housing. 2 radial and axial loads.
The other side is the so-called free side, which only bears the radial load and can move relatively Problems Needing axially. This solution produces the temperature change of the title of the telescopic shaft and the spacing error of the installed bearing.
For fixed side bearings, the rolling surface can choose to move axially, such as cylindrical roller bearings or assembled moving (such as centripetal ball bearings). On the relatively short shaft, the fixed side and other cases have no side effects and only one unidirectional fixed axial moving bearing (thrust ball bearing).
Rolling ina bearing is a precision part, so it should be used with great caution. Even high-quality ina bearings will not get the Problems Needing expected effect if they are not used properly.
Precautions for the use of INA Bearing are as follows.
Keep ina bearings and their surroundings clean
Even the tiny dust invisible to the naked eye will bring adverse effects to ina bearings. Therefore, keep the surroundings clean so that dust will not invade ina bearings.
Use with care.
Strong impact on INA Bearing in use will produce scars or indentation and induce accidents. In serious cases, it will cause cracks and fractures, which must be paid attention to.
Use ina bearing special tool.
Special tools must be used and cannot be replaced at will.
Avoid rust of INA Bearing.
When operating ina bearings, hand sweat can cause rust. Pay Problems Needing attention to operate with clean hands, wear gloves as much as possible, and pay attention to corrosive gases.
Whether ina bearing is installed correctly directly affects the accuracy, service life and performance of bearing. Problems Needing Therefore, the design and assembly department should fully study the installation of INA Bearing and carry out it according to the operation standards. Operation standard items are usually as follows:
Clean INA Bearing and related parts
Check the size and accuracy of relevant parts
Check ina bearing after installation
When unpacking the bearing, it is hoped that the ina can be installed again. During general grease lubrication, the bearing is not cleaned, but directly filled with grease. In case of oil lubrication, it is generally not necessary to clean.
However, ina bearings for instrument or high-speed use Problems Needing should be cleaned with clean oil to remove the rust inhibitor coated on ina bearings. INA Bearing with rust inhibitor removed is easy to rust, so it cannot be placed at will.
In addition, ina bearings sealed with grease can be used directly without cleaning.
The installation method of INA Bearing varies according to the bearing structure, fit and conditions. Since it is generally shaft rotation, the inner ring needs interference fit. Cylindrical bore ina bearings are usually pressed in with a press or hot installed. In the case of tapered hole, it is directly fixed on the tapered shaft or installed with a set sleeve.
Clearance fit is often used when installing to ina bearing seat. When there is interference in the outer ring, it is usually pressed in by press or installed by cold shrinkage method after cooling.
Dry ice is used as the coolant. In the case of cold contraction installation, the moisture in the air will condense on the surface of the bearing. Therefore, anti rust measures need to be taken.
3. Operation inspection
After the ina bearing is installed, in order to check whether the installation is correct, the operation inspection shall be carried out. Small machinery can be rotated by hand to confirm whether it rotates smoothly. The inspection items include poor operation caused by foreign matters, scars and indentation,
unstable torque caused by poor installation and poor processing of mounting base, excessive torque caused by too small clearance, installation error and sealing friction, etc. If there is no abnormality, the power operation can be started.
Large machinery cannot rotate manually, so the power shall be cut off immediately after no-load start, and the machinery idles. Check whether there is vibration, noise, contact of rotating parts, etc. after confirming that there is no abnormality, enter the power operation.
Power operation, starting from no-load and low speed, slowly increase to the rated operation under the specified conditions.
During the test run, the inspection items are whether there is abnormal sound, ina bearing temperature change, lubricant leakage or discoloration, etc. If any abnormality is found, stop the operation immediately, check the machinery, and remove the bearing for inspection if necessary.
Ina bearing temperature can generally be inferred from the external temperature of the bearing pedestal. However, it is more accurate to directly measure the temperature of ina bearing outer ring with oil hole.
The temperature of INA Bearing increases gradually from the beginning of operation, and the temperature is usually stable after 1 ~ 2 hours. If ina bearing is not installed properly, the temperature will rise sharply, resulting in abnormal high temperature.
The reasons include too much lubricant, too small clearance of INA Bearing, poor installation, excessive friction of sealing device, etc. In the case of high-speed rotation, the wrong selection of INA Bearing Structure and lubrication mode is also the reason.
The rotating sound of ina bearing is checked with stethoscope, and there are strong metal noise, abnormal sound, irregular sound and other indications of abnormality. The reasons are poor lubrication, poor accuracy of shaft or ina bearing seat, bearing damage, foreign matter intrusion, etc.
Ina bearings need to be removed during regular maintenance and replacement. After disassembly, if you want to continue to use or need to check and investigate, disassembly should be as careful as installation.
Pay attention not to damage the bearing and parts, especially the interference fit bearing, which is difficult to operate, so it should be considered in advance in the design stage to facilitate disassembly. It is also very important to design and make disassembly tools according to needs.
During disassembly, the disassembly method and sequence shall be studied according to the drawings, and the matching conditions of INA Bearing shall be investigated, so that the disassembly operation can be carried out smoothly.