SKF bearings installed standards

SKF bearings installed standards

When it is mounted to the housing, generally there is more clearance fit and the outer ring has an amount of interference. Usually, it is press-fitted with a press, or there is also a shrink-fitting method that is installed after cooling. When dry ice is used as the coolant and the shrink-fit installation is installed, the moisture in the air will condense on the surface of the SKF bearing. Therefore, proper rust prevention measures are needed.
1. Installation of cylindrical bore bearings (1) Method of press-fitting with presses Small SKF bearings are widely used for press- fitting presses. The pad is inserted into the inner ring and is pressed silently against the inner ring with a press and closely contacts the shaft stop shoulder. To install the inner ring with a pad on the outer ring is a cause of indentation and crushing on the raceway. Therefore, it must be prohibited.
When operating, apply oil on the mating surface. If you have to use a mallet to beat the installation, you must put padding on the inner ring. This practice has often been the cause of SKF's imported bearing operations, so it is limited to the use of small amounts of interference and cannot be used for large amounts of interference, or for medium to large SKF bearings.
For non-separable SKF bearings such as deep groove ball bearings, where the inner ring and the outer ring are required to be installed in an interference amount, pads are used, and the inner ring and the outer ring are simultaneously pressed with a screw or oil pressure. The self-aligning ball bearing outer ring is easy to tilt, even if it is not an interference fit, it can be mounted on the pad.
Such as cylindrical roller bearings, tapered roller bearings, such as the separation of SKF bearings, the inner ring, outer ring can be installed on the shaft and the shell, the inner ring and the outer ring are installed when combined, the key It is a matter of stabilizing the two so that the two centers do not deviate from each other. Pressing in and pushing them in will cause a race on the raceway surface.
(2) Hot-loading method Large-size SKF bearings require a lot of force when they are pressed in, so they are difficult to press. Therefore, the SKF bearing is heated in the oil to expand it, and then the hot charging method to the shaft is widely used. Using this method, SKF bearings can be added without adding undue force to complete the operation in a short time.
The heating temperature of SKF imported bearings is based on the SKF imported bearing size and the required amount of interference. Hot installment related matters are as follows:
(a) Do not heat SKF bearings above 120°C;
(b) In order to prevent SKF bearings from directly contacting the bottom of the tank, it is advisable to place the SKF bearings on a metal mesh table or to suspend the SKF bearings.
(c) Heat the SKF bearings to a temperature 20°C to 30°C above the desired temperature so that the inner ring does not cool during operation and is difficult to install;
(d) After installation, bearings imported from SKF cool down and shrink in the width direction, so they must be tightened with a shaft nut or other suitable method.
(__ To prevent gaps between the inner ring and the SKF bearing bearing shoulder.
2. Installation of conical bore SKF bearings Cone bore SKF bearings are used to directly fix the inner ring to the conical shaft, or to install the sleeve onto the cylindrical shaft. Large-scale self-aligning SKF bearings are installed with hydraulic pressure.
3. Operation Check After the installation of SKF bearings is completed, in order to check whether the installation is correct, it is necessary to check the operation. The small machinery can be rotated by hand to confirm whether the rotation is smooth. The inspection item is caused by the unsmooth operation due to foreign materials, scars, and indentations, uneven rotation torque caused by improper mounting of the mounting seat, excessive clearance, and installation error, and large torque due to seal friction. . If there is no abnormality, you can start power running.
Since the large machinery cannot be manually rotated, the power is turned off immediately after the start of the no-load operation, inertial operation is performed, vibrations or sounds are detected, and the rotating parts are in contact with each other. After confirming that there is no abnormality, the power is turned on.
The power operation starts from the no-load low speed and gradually increases to the predetermined conditional rated operation. The test items during the test run include abnormal sound, SKF bearing temperature transfer, lubricant leakage, and discoloration. If any abnormality is found in the test run, the operation shall be suspended immediately, the machine shall be inspected, and if necessary, the SKF bearing bearing inspection shall be dismantled.
SKF imported bearing temperature check is generally known from the outer shell surface. However, the use of oil holes to directly measure the bearing outer ring temperature is more accurate. The temperature of SKF bearings began to gradually increase. If there is no abnormality, it is usually stable after 1~2 hours. If bearing or installation is not good, SKF's imported bearing temperature will rise sharply and cause abnormally high temperatures. The reasons such as excessive lubricant, SKF bearing clearance is too small, poor installation, sealing device friction and so on. In the case of high-speed rotation, the selection of the lubrication method for the SKF bearings is also the cause.