During the operation of the bearing, certain vibration is always unavoidable. With the extension of the use time, bearing vibration will be very sensitive to bearing damage, such as peeling, indentation, rust, cracks, wear, etc., which will be reflected in the bearing vibration measurement. Generally, we can use a special bearing vibration measuring device to measure the magnitude of vibration.

Generally, there are two main types of bearings on bicycles: bearing and bead stop. In addition, there is another weird thing about a rolling pin, so I won't discuss it here.
This problem is mainly focused on the hub. Bearings in these places have requirements for lubricity and strength of axial force and radial force at the same time. In places like the rotation point of the shock absorber of the frame, the main consideration is the radial force, so almost all of them are bearing.
Traditionally, the hub that is independently embedded in the bearing assembly is called "Peilin", and the two ends of the hub are driven into the pan bowl, the balls are discharged into the pan bowl, and the bearing driven by the rotation of the ball is called the "ball stop". .
In layman's terms, the bearing can be dismantled as a whole and become the ring-shaped "ball bearing" that everyone usually sees.

Deep groove ball bearings (GB/T 276—1994) originally listed radial ball bearings are the most widely used rolling bearing. It is characterized by low frictional resistance and high speed. It can be used on parts that bear radial load or a combined load that acts on both radial and axial directions. It can also be used on parts that bear axial load, such as low-power motors, Automobile and tractor gearboxes, machine tool gearboxes, general machines, tools, etc. And bearing noise is inevitable, so many choose low-noise deep groove ball bearings when selecting bearings. Are the installation and adjustment of low-noise deep groove ball bearings the same as the bearings used in normal times? The editor is here today to share with you about the correct installation and adjustment of low-noise deep groove ball bearings.

As a member of many reducers, planetary reducers are widely used in major machinery industries due to their small size, light weight, high precision, and long life. Its interior is composed of single-stage or multi-stage planetary gear trains, with compact structure, small volume and high transmission efficiency. Then, abnormal noise is the most common and frequent problem of planetary reducer due to heavy load and harsh use environment. The structure of the planetary reducer is mainly divided into several parts: connecting plate, coupling, lower cover, sun gear, planetary gear, inner gear ring, upper cover and planetary support. The following is to find the reason from the inside of the reducer. Explain the common reasons for zu separately:

1. The gear meshing gap is too large

This situation is common in abnormal noises that only appear after a period of use. The newly assembled planetary reducer has a good gear meshing. After a period of use, the abnormal noise is particularly loud. The reason is that the manufacturer uses unqualified gears. The low price causes the gears to have insufficient hardness, severe wear, or planetary carrier deviation. It is recommended Purchase B&R planetary gearboxes.

2. Parts damaged and dropped. Planetary reducers often receive large load impacts. Under the continuous action of the load, the bearings, gears and other parts are damaged and dropped. The damaged parts fall into the body and cause abnormal noise. It is necessary to clean the fallen parts of the parts in the body in time, and replace the damaged parts.

3. Large bearing clearance

This abnormal noise is periodic and increases with the increase of the speed. The bearing is mainly composed of inner ring, outer ring, rolling element and cage. Large bearing clearance means that the gap between the roller and the inner and outer rings is too large. During operation, the rolling elements collided with the inner and outer rings, causing abnormal noise.

4. Gear tooth side lash is too large

This kind of abnormal noise often occurs at the moment the reducer starts, and disappears during continuous operation. (In order to form a lubricating oil film between the meshing tooth profiles and avoid jamming due to the frictional heating and expansion of the gear teeth, there must be a gap between the tooth profiles. This gap is called the tooth side gap) ww. femander. com If the gap is too large, a strong impact force will occur at the moment of contact between the gear teeth, and an abnormal impact will occur. Under normal circumstances, the planetary reducer will have noise. If the sound is particularly loud, it will exceed The noise value marked by the manufacturer is an abnormal noise, which may be caused by a large tooth backlash. If the noise cannot be tolerated, it is recommended to replace the planetary reducer of other brands.

5. The difference between the parts

The planetary gear reducer is assembled by humans. Concentricity deviations may occur between the various parts. In ancient countries, if the deviation exceeds the allowable range, abnormal noises will occur. The reason for the abnormal noises is the effect of unbalanced forces. Due to the uneven distribution of the work load Uniformity and unbalanced work force will affect the service life of the reducer. It is recommended to dismantle and reassemble.

6. Gear toothing

This kind of abnormal noise is particularly loud, and the impact sound is generally "click...", and it is periodic. It is recommended to replace the gear and the ring gear.

7. Insufficient lubricating oil

Since the reducer is often installed inside the equipment, oil leakage cannot be detected in time. This is because there may be no lubricating oil protection between the gears and the gears, the gears will accelerate wear and abnormal noises.

There are many kinds of abnormal noises of planetary reducer. If such a situation is found, you should first stop, check the equipment, and deal with it in time. This completely solves the problem of abnormal noise of planetary reducer, avoids further damage to the reducer, and restarts. produce.

When the stress of high temperature bearing parts exceeds the fracture limit stress of the material, fractures and local fractures occur inside or on the surface. This phenomenon of discontinuity or fracture of the material is called crack.

There is a kind of hair-like cracks on the surface or under the surface of the material called hairline. When the hairline expands to a certain extent, the phenomenon that part of the material is completely separated from the part matrix is ​​called fracture.

The cracks are generally linear, with variable directions, a certain length and depth (width), and sharp roots and edges. Cracks are divided into internal cracks and surface cracks, as well as visible and invisible to the naked eye. For invisible cracks to the naked eye, non-destructive testing methods are required for observation. The hairline is generally in the shape of a thin line, and the direction is intermittently distributed along the rolling direction of the steel, with a certain length and depth, sometimes single or several.

The causes of cracks are more complex, and there are many influencing factors, such as raw materials, forging, stamping and folding, heat treatment, grinding, and local excessive stress. The reason for the formation of hairline is the bubbles or inclusions generated in the smelting process of steel, which exist on the surface of the material after being deformed by rolling. For cracks that are not visible to the naked eye, non-destructive testing methods are required for observation.

The preventive measures for cracks mainly include the control of raw material defects such as non-metallic inclusions, surface slag inclusions, folding, microscopic pores, shrinkage holes, bubbles, etc. in manufacturing. Control processing stress, such as internal stress (thermal stress and structural stress), grinding stress, stamping stress, etc. generated during heat treatment and quenching. In use, pay attention to abnormal knocks (bumps) during the bearing installation process and excessive local stress caused by poor installation. In addition, it is necessary to ensure lubrication, enhance the sealing effect, control the inflow of external impurities, and avoid contact between the bearing and corrosive substances.