Introduction and installation of self-aligning roller bearings
Source: Zhonghua Bearing Network
The self-aligning roller bearing has a double row of rollers. The outer ring has a common spherical raceway, and the inner ring has two raceways and is tilted at an Angle relative to the bearing axis.
This kind of ingenious construction makes it self-aligning, so it is not easy to be affected by the Angle of the shaft and bearing box on the error or bending of the shaft, and it is suitable for the occasion of the error caused by the installation error or deflection of the shaft.
The bearing can bear radial load as well as bi-directional axial load.
There are two kinds of internal holes of self-aligning roller bearing, cylindrical and conical, the taper of conical taper hole is 1:30 and 1:12. This kind of conical internal hole bearing is equipped with a fixed set sleeve or a detuning sleeve, so that the self-aligning ball bearing with conical internal hole can be conveniently and rapidly assembled on the optical shaft or step machine shaft.
The types of self-aligning roller bearings are: self-aligning roller bearings (20000CC type);
Taper hole self-aligning roller shaft bearing (type 20000CCK);
Self-aligning roller bearing (20000CC/W33 type);
Taper bore self-aligning roller bearing (20000CCK/W33 type);
Self-aligning roller bearing mounted on a set sleeve (type 20000CCK H);
There are 6 kinds of self-aligning roller bearings (20000CCK/ W33H type) mounted on the compact sleeve.
Installation of self-aligning roller bearings
A self-aligning roller bearing is fitted with a drum roller bearing between an inner ring with two raceways and an outer ring with a spherical raceway.
The curvature center of the raceway surface of the outer ring is consistent with the bearing center, so it has the same tuning function as the automatic aligning ball bearing.
When deflection occurs in the shaft and shell, the load can be automatically adjusted and the axial load in two directions.
Large radial load capacity, suitable for heavy load, impact load.
The inner diameter of the inner ring is a taper bore bearing, which can be installed directly.
Or use a fixed sleeve, remove the barrel and install it on the cylindrical shaft.
The cage is made of steel plate stamping cage, polyamide forming cage and copper alloy car.
For self-aligning bearings, the use of an intermediate mounting ring prevents inclination and rotation of the outer ring when the bearing with shaft is loaded into the box shaft hole.
It should be remembered that some sizes of self-aligning ball bearings have balls that protrude from the side of the bearing, so the middle mounting ring should be recessed to prevent damage to the ball bearings.
A large number of bearings are usually installed mechanically or hydraulically.
For separable bearings, the inner and outer rings can be installed separately, which simplifies the installation process, especially if both inner and outer rings need interference fit.
When the shaft with the inner ring in place is loaded into the bearing box with the outer ring, attention must be paid to check whether the inner and outer rings are correctly aligned to avoid scratches on the bearing raceway and rolling parts.
If cylindrical and needle roller bearings have an inner ring without a flange or an inner ring with a flanged edge on one side, a mounting sleeve is recommended.
The outer diameter of the sleeve shall be equal to the inner ring raceway diameter F, and the machining tolerance standard shall be D10.
Pressed outer ring needle roller bearing is best installed with mandrel.
Attention to installation and use of self-aligning roller bearings
The preload of the self-aligning roller bearing is carried out at room temperature, but in the working state, the drive shaft generated by the micro-stretching temperature rise of the system, the preload of the bearing will change, therefore, set the preload, you should take this factor into account.
It requires the ability to size, speed, and other conditions set for the proper use of the self-aligning roller bearing preload to ensure transmission for life.
If the preload is too large, power consumption, or even lead to overheating.
If the pretension force is too small, the body load, the shaft rolling, the gap between the outer ring under the action, produces the runout, runs, transmission accuracy, to reduce the noise increase, affects the gear meshing, severely damaged when the teeth and bearings.
According to different self-aligning roller bearing assembly, such as: directly by the axial compression of the inner ring of the bearing bearing pretighten nut rotation, inner ring and outer ring, to eliminate the gap, to achieve the purpose of bearing preload.
Achieve common use: far beyond the preloaded bearing, nut at the end, and then back to 1/4 turn.
Assembly method. The advantages of this method are less investment, simplicity, practicality, and consistent superior quality under the premise of tapered roller bearings. It can all be used.
1. Heating method Of electric heating plate: put the bearing on the electric heating plate with the temperature of 100℃ for a few minutes. This method is the most simple, for example, several times of rolling can make the bearing evenly heated, and the efficiency is high.
2, the electric furnace heating method will be placed in the closed automatic temperature control electric furnace heating, heating uniform, temperature control accurate, fast heating, suitable for a lot of heating bearing occasions;
3, induction heating method using the induction heater can quickly, reliably and cleanly adjust the self-aligning roller bearing to the required temperature, this is particularly suitable for the occasion of the inner ring tight match, because only the inner ring is heated, and the outer ring is less heated, so that it can be more easily mounted on the shaft, and easy to be loaded into the seat hole
4 or the light bulb heating heating method using 50 w bulb spherical roller bearings, can guarantee the heating temperature about 100 ℃, the smaller the bearing can be directly on the bulb, larger bearings taper enclosure may be placed on a light bulb, conical cover can prevent heat losses, light bulbs and uniform heating cone cover can be adjusted up and down, in a certain heating range that can adapt to different size of bearing using infrared light bulb, pay attention to the direction of light bulbs should be down, in order to avoid this kind of bulb of infrared radiation is bad for the eyes can be energy-saving bulb heating method is suitable for small and often do not need;
To heat the bearing, the bulb can also be used for lighting, in addition to any other equipment is not required;
5 oil, heating method which is widely used in the traditional heating method, the bottom of the tank from 50 to 70 mm in a metal mesh, bearing on the Internet, large bearing to hoist hooks in the bearing should not be placed directly on the bottom of the channel, in case of contact with the bottom of the channel bearing parts of the local heat is too high, or the bottom of the channel deposition of dirt into the bearing oil tank heating method of the key points are as follows, should use no corrosive thermal stability good mineral oil, transformer oil, it is best to oil and the capacity of the container should be kept clean oil tank should be heated and spherical roller bearing and the size of the oil, if the container is too small, in continuous operation, one into the bearing oil temperature will drop quickly,
It doesn't work very well.