Three identification method for bearing fault
Bearing as a mechanical equipment on the precision parts, how to improve the productivity of the plant, the first mechanical equipment performance must be the best, and the relationship between the use of mechanical equipment performance, one of the largest - bearing. So the factory in the production process, must be on the mechanical equipment in the bearing for a good inspection. For the sake of safety, the Chinese bearing network shared bearing fault three identification method, we want to help.
1, through the sound recognition
To identify the sound through the need to have a wealth of experience. Must be trained to achieve the recognition of bearing sound and non bearing sound. To this end, should be as far as possible from the person to carry out this work. The sound of a bearing can be heard clearly on the shell with a listening device or an audio stick.
2, through the working temperature of recognition
The method belongs to the method of comparison and identification, which is limited to the situation that is not changed in the running state. To this end, the need for continuous temperature records. When the failure occurs, the temperature will not only increase, but also the irregular changes. The method and the method of sound recognition are appropriate.
3. Identification of the state of lubricant.
Analysis on lubricant sampling, through its pollution level, whether mixed with foreign body or metal powder to judge. This method is especially effective for the bearing or large bearing which is not close to the observation.
Teach you how to lock the bearings
Bearings are generally divided into two kinds of lock method:
1 attached to the bearing of the screw
Just to extend the inner part of the inner ring of the screw lock, you can put the export bearing seat, staring at the screw with six angle wrench to lock. Please select the appropriate size of the six angle wrench.
2 attached fair lock sleeve bearing
A fair lock sleeve has a concave, which is equal to its inner hole, and a part of the inner ring of the bearing seat is fair. First put on the inner ring on the inner ring, the direction of the axis of the rotation, the fast rotation of the fair bearing sleeve know the card, with a six angle wrench lock screw.
Advantages of ceramic bearings
First, because the ceramic is almost not afraid of corrosion, so the ceramic rolling bearings suitable for corrosive media in the harsh conditions of the work.
Second, due to the low density of ceramic ball rolling ball, the weight is much lighter, so the centrifugal effect on the outer ring can be reduced by 40%, and the service life is prolonged.
Third, the ceramic heat expansion and cold contraction effect is smaller than the steel, so the bearing clearance must, allows the bearing on the temperature changes more intense work.
Fourth, because the elastic modulus of ceramic is higher than that of the steel, it is not easy to deform, so it is advantageous to improve the working speed and achieve higher precision.
In summary, as a result of ceramic bearings in the application has so many advantages, so the major imported bearing manufacturers such as: SKF bearings, FAG bearings, FAG bearings are involved in this field and the introduction of the corresponding products.
High temperature bearing installation key points
One, check. The bearing body, bearing and sealing ring carefully examined, anti-corrosion oil removal, macroscopic examination again to the bearing of the bearing seat, surface and bearing seat is bright and clean, smooth, should not dent, crack, rust, burr and other stress concentration caused by defects, after the examination should be on the component surface cast black lead powder (note to use compressed air blowing have been to many black powder), to prevent corrosion.
Two, matching number. In order to prevent the bearing bite and reduce wear bearing materials, should be better than the 1 level low bearing body, low hardness HB20 ~ 50. In order to prevent the bearing body and the bearing base of the random matching, the hardness difference is too big or too small, the bearing block and the bearing base should be matched and numbered according to the value of hardness test. Number should be used in the steel digital to fight in the bearing body, bearing seat is not easy to damage the position of the position, the force and not easy to destroy the end.
Three, sealing ring inspection and grinding. Modern large size units, high temperature of bearing using spherical sealing ring can greatly eliminate the bearing body of the additional bending stress, in the installation process is important to grasp is sealing ring and the bearing seat bearing surface and the sealing ring and the cylinder / flange bearing surface contact check, mainly Tu Hongdan and the feeler to check the gap in two ways, such as the discovery of uneven contact, received permission to use grinding bearing bearing surface and the cylinder and flange bearing surfaces method processing. The inspection also should be carried out in the sealing ring and bearing block for many times to check, if can offset the contact deviation, it can greatly reduce the processing workload.
Four, installation. In front of the bearing body final installation and fastening and deal with the bearing body of careful examination last, removal of debris and ash, especially in the bearing seat between the debris, and the cylinder, valve planted wire holes were carefully cleaned to remove all debris and water. Bearing body, bearing seat should not affect the performance and reliability of damage, the installation of the bearing body, bearing seat, sealing ring direction. Bearing of the bearing seat in place should be coated with MoS2 high temperature anti bite lubricant, but the bite proof agents should not be used for containing nickel alloy steel bearing body (instead of copper graphite lubricant). Cold tightening and thermal fastening are from the cylinder sag the widest part (central) began, in order to symmetrical two ends of, due to tight first bearing body tightening force after fastening bearing adjacent body will reduce, so cold tightening and thermal fastening should tighten 2 times. The heating position of the bearing body is the central hole of the bearing body, avoiding the bearing block and the bearing seat of the direct heating bearing body.
How to ensure that the bearing does not produce a large defo
In order to ensure that the bearing in the installation does not produce a large deformation, must do the following five points:
1, the installation of roundness and squareness of shaft and hole shoulder according to the corresponding precision bearings to requirements;
2, not only to calculate the amount of interference with the rotating ring, but also the accurate calculation of ring with appropriate amount;
The rotating ring of burning of interference within the possible range should be made smaller. As long as the thermal expansion of the working temperature is ensured, and the influence of the centrifugal force at the highest speed, it is not caused by the movement or sliding of the surface. Ferrule is fixed according to the load size and bearing size selected minimum clearance fit or interference fit, because too loose or too tight is not conducive to maintain the original precise shape.
3, the bearing under the condition of high speed operation, high working temperature should be special attention to the support of rotating rings can not be too loose, to prevent the emergence of the eccentric vibration, and fixed rings with no gaps, to prevent the ring under the load deformation and vibration excitation.
4, on the fixed ring take peccadillo fit conditions is both sides of the surface of the match has very high shape precision and low roughness, otherwise the result of difficult installation and removal more difficult. In addition, there is a need to consider the influence of spindle thermal elongation.
5, to use a pair of double contact ball bearing spindle. Because it is half load lighter, with the amount of interference such as too large, is the internal axial preload will obviously on the high side, will adversely affected. Use of double row short cylindrical roller bearings and tapered roller bearings spindle, its load is relatively large, so it is also relatively large surplus.
Angular contact bearings accuracy test
After the angular contact ball bearings into the spindle mounting accuracy of calibration sequence is as follows (in shaft diameter 60-100mm lathe for example):
(1) Measure the shaft and the bearing hole size to determine with precision bearings, with the following requirements:
Take the inner ring and the shaft interference fit, the amount of interference 0 ~ + 4μm (at light load, when precision is 0); take the outer ring and the bearing hole gap with the clearance amount 0 ~ + 6μm (but at the free end of the bearing When using angular contact ball bearings, but also increase the gap); shaft and housing bore surface roundness error in 2μm or less, face parallelism bearing cage used in 2μm or less, the external end face of the inner shaft shoulder end of beating 2μm or less; retaining shoulder of the housing bore axis of beating 4μm or less; cover front side facing the axis of the spindle runout in 4μm or less.
(2) the fixed end of the front bearing mounted on the shaft
After the bearings were cleaned thoroughly washed with clean kerosene, grease lubrication, the first containing 3% to 5% of the grease into the bearing organic solvents for degreasing, then the quantity of oil gun grease filled within the bearing (accounting bearing space volume of 10% to 15%); heating the bearing temperature elevation 20 ~ 30 ℃, an oil press the bearing onto the shaft; the adapter sleeve bears on the shaft and bearing a suitable pressure against the axial end face of it The spring scale tape volumes on the bearing outer ring, the pre-load starting torque measurement methods specified check whether there is a significant change (even when the bearing is correct, but the fit or deformation of the holding frame, the preload there; Positioning Change possible).
(3) the bearing - the shaft assembly into the housing bore
Heated seat hole makes temperature 20 ~ 30 ℃, with continuous pressure gently bearing - the shaft assembly into the housing bore; before adjusting cap, the amount of fastening the front cover of 0.02 ~ 0.05μm, to the outer face of the bearing housing reference, the dial gauge header conflict on the journal surface, the axis of rotation measured beating error of 10μm the following requirements; the dial gauge positioned on the shaft, the back seat of the interior surface of the header conflict, the rotation axis front and rear seat to measure the bearing bore concentricity.
(4) The free end of the bearing may be selectively placed in a position to offset the bias, attached to the rear bearing support position, as much as possible to offset the roundness and concentricity deviation deviation between each other.