Bearings are common parts and important parts in mechanical equipment, and the use of bearings is also very extensive. In order to make more money, there are many black-hearted merchants who use the old to recharge, and recycle some used or unused old bearings to buy them as new bearings after processing. This kind of refurbished bearings is still very different from good bearings. It is not as good as a good bearing. Based on the knowledge of bearing knowledge, China Bearing Network will share with you the difference between a refurbished bearing and a good bearing, and how to identify whether the bearing is a refurbished bearing when buying a bearing.
Differences between refurbished bearings and good bearings:
1. The size of the refurbished bearing has changed. Small outer diameter and large inner diameter can be measured with a ruler.
2. Check the bearing surface accuracy and whether it is smooth. Refurbished bearings are rough.
3. The refurbished bearing is rotated unevenly by hand.
4. Observe that the gap between the cage and the rolling element of the refurbished bearing is larger than the normal gap.
5. Look at the bead refurbished bearing beads of different sizes, and there will be wear and deformation.
6. Look at the slideway. The refurbished bearing slideway has irregular wear and deformation.
A good way to identify refurbished bearings:
1. Refurbished bearings are generally limited by the technology and equipment of small bearing manufacturers, so the bearing accuracy is low, the bearing surface is rough, the chamfer size is uneven, and some have black skin and pitting.
2. The materials used for some inferior bearings are ordinary steel, carbon steel, malleable steel and iron pipes, etc., and the appearance of these materials is mostly white, and the color of special bearing steel is greenish. But just looking at the color can't fully conclude that the hardness needs to be done. Ordinary steel has low hardness.
3. Some small manufacturers have simple dipping technology, and the bearing is not uniformly heated, and there will be slight deformation.
4. Rotate the bearing to see whether the bearing rotates evenly and whether the sound is continuous and no noise.
5. Looking at the cage, the bearing cage of the regular manufacturer is regular and free of burrs, the rivet head of the riveted bearing cage is the same size, and the processing technology and equipment of the informal manufacturer are simple, so the cage is rough, and some riveted structure cages are unevenly divided. With or against the offset, the size of the rivet pier head is different or the rivet is offset.
6. Look at the packaging. The regular manufacturers have the same packaging, and the fonts on the packaging are clear. Some counterfeit bearings have inconsistent packaging, or are simple and irregular.
7. Look at the font on the end face of the bearing. The original bearing is very clear and uniform regardless of the steel font or the laser font. The laser font has a certain depth. The counterfeit bearing font has broken marks. After the font is wiped with gauze, it will leave a faint trace of the font.
8. Look at the certificate. Regular manufacturers have the certificate and the size of the certificate is the same. Most of the certificate paper is oil-proof paper. The fonts are clear, some manufacturers have query information on the certificate, the certificate is counterfeit, the font is blurred, the paper is ordinary paper, and the size of the certificate is different. It is recommended to keep the formal manufacturer's certificate for comparison and reference.
9. Some imported bearings are different from domestic ones in terms of anti-rust oil. Imported bearings are not without anti-rust agent but can not see traces. The bearing surface is clear, while some counterfeit imported bearings are coated with domestic anti-rust agent and feel sticky in the hand. Gooey, will taste a smell of anti-rust oil.
10. Understand and understand the normal products of some regular manufacturers in the bearing typing specifications, such as: bearing model, trademark, year code. And some fake bearing fonts are engraved, even if some fonts are blurred by laser.
11. If possible, it is best to visit the bearing manufacturer or brand dealer in person.