Amy Hookah,Metal Hookah ,Zinc Alloy Hookah Fenghua Jade Motor Co., Ltd. , http://www.qiuzanhookah.com
The common damage to the bearing shell is wear, scratching, melting and peeling of the alloy layer, but sometimes there are some abnormal damage phenomena. 1. Abnormal grinding of bearing bushes (1) The bearing bushes of the bearing bushings are to be poured. 2. The selected bearing shell is not suitable, and the amount of interference is too large, so that it is pressed into the watts and deformed too much after tightening the watt cover. Therefore, attention should be paid to checking the free opening elastic tensor and the height of the protruding watts of the bearing pad during the inspection. If the free opening elastic tensor is too small, it should be re-selected. If the bearing is too high, you can repair a little at the end of the bearing without locating the key. (2) The side edges of the bearing bush are eccentrically worn. It often appears on the surface of the shoe that is working with the newly dressed crankshaft journal. This is due to the fact that the journal busbars are concave in the center due to improper grinding. In order to prevent this from happening, when testing the worn journal, in addition to measuring the diameter of both ends as required, the middle data of the journal should also be measured. When the technical requirements are not met, the crankshaft should be reground. The neck can't be cobbled by simply jotting the bearing. 2. Bearing erosion Corrosion of bearing bushes mainly occurs on copper-lead alloy bearing bushes without plating. The working surface of the entire bearing bush shows pinhole-like pits or pits, and the surface of the bush is black. The main reason is that the lubricating oil has seriously deteriorated or misused the lubricating oil. 3. There are wear marks and rust spots on the backing of the bearing. Sometimes there will be a large area of ​​dark areas on the backing of the bearing pad, and there will be obvious signs of friction along the circumferential direction. In severe cases, the bearing hole of the bearing pad will appear elliptic due to wear. The main cause of this fault is the lack of fit between the bearing shell and the seat hole or the wear of the locating key. At this time, under the effect of the periodic load, a slight misalignment in the circumferential direction is repeatedly generated between the bushing backing and the bearing seat hole, which causes the bush backing to generate heat and further oxidize and rust. Therefore, during installation, it is necessary to check the interference of the bearing bush (ie, the height of the bearing surface of the bearing bush) and the positioning of the bearing bushings. In addition, the tightening torque of the bearing cover bolt must be uniform and consistent. When the bearing seat hole is out of round due to wear or the hole neck becomes large, tin or zinc may be plated on the seat hole surface. 4. Cracking Cracking refers to the occurrence of subtle cracks on the surface of the bearing alloy, and the cracks are criss-cross and reticulate, with no regularity or fixed direction. Cracking is a kind of fatigue damage phenomenon of the bearing shell. If it is not processed, the oil penetrates into the crack during work, and a wedging effect is generated, which easily causes the alloy layer to fall off into pieces. Cause cracks: 1, the bearing temperature is too high. 2. Overload or out-of-round of the bearing bush, accompanied by a powerful impact force in the work. 3, uneven wear of the bearing, so that uneven load distribution. During the repair process, the thickness of the alloy layer and the bearing clearance of the bearing can still be ensured after grinding or scraping the crack layer with sandpaper. After eliminating the failure factors, the bearing can be installed and used again. Otherwise, the new part should be replaced after troubleshooting. . 5. After the holding of tiles in the holding tiles, corresponding measures should be taken according to the degree of holding. If the bearing bush forms several shallow grooves in the vicinity of the crankshaft hole, it can be scraped and used for a period of time. If the bushing alloy layer is mostly transferred or the whole piece falls off, it can no longer be used. The area of ​​contact between the scraped bearing alloy layer and the crankshaft journal is required to be above 75%. When testing the contact area between the bearing bush and the journal, the method of applying red oil is often used. However, if it is an aluminum alloy bush, because of its low hardness, it can show contact marks without applying red oil. Generally, the alloy layer of the aluminum alloy bearing bush is gray, and if the bright part of the bearing bush is exposed, it is the contact mark.