Chain maintenance
Methods and steps
1. The sprocket should be installed on the shaft without skew and swing. The end faces of the two sprockets in the same transmission assembly should be located in the same plane. When the sprocket center distance is less than 0.5 meters, the deviation is allowed to be 1 mm; when the sprocket center distance is more than 0.5 meters, the deviation is allowed to be 2 mm. However, there is no friction on the side of the sprocket teeth. If the two wheels are offset too much, it is easy to cause chain derailment and accelerated wear. When replacing the sprocket, you must pay attention to checking and adjusting the offset.
2. The tightness of the chain should be appropriate. Too tight increases power consumption and the bearings are easy to wear; too loose The chain is easy to jump and derail. The tightness of the chain is: when it is lifted or pressed down from the middle of the chain, the center distance between the two sprockets is about 2-3cm.
3. If the new chain is too long or stretched after use, it is difficult to adjust. The chain links can be removed depending on the situation, but they must be an even number. The chain links should pass through the back of the chain, the locking plate is inserted outside, and the opening of the locking plate should face the opposite direction of rotation.
4. When the sprocket is seriously worn, the new sprocket and the new chain should be replaced at the same time to ensure good meshing. Do not replace the new chain or the new sprocket alone. Otherwise, it will cause poor meshing and accelerate the wear of the new chain or the new sprocket. When the sprocket tooth surface is worn to a certain extent, it should be turned over in time (referring to the sprocket used on the adjustable surface). To extend the service life.
5. The old chain cannot be mixed with some new chains, otherwise it is easy to produce impact in the transmission and break the chain.
6. The chain should be filled with lubricating oil in time during work. The lubricating oil must enter the matching gap between the roller and the inner sleeve to improve working conditions and reduce wear.
7. When the machine is stored for a long time, the chain should be removed and cleaned with kerosene or diesel, and then coated with engine oil or butter and stored in a dry place to prevent rust.
Appearance inspection of the chain
1. Whether the inner/outer chain pieces are deformed, cracked, or corroded
2. Whether the pins are deformed or rotated, or corroded
3. Whether the rollers are cracked, damaged, or excessively worn
4. Whether the joints are loose or deformed
5. Whether there are abnormal sounds or abnormal vibrations during operation, and whether the chain is in good lubrication condition
Inspection method
The chain length accuracy should be measured according to the following requirements:
1. The chain is cleaned before measurement
2. The chain to be measured is surrounded by two sprockets, and the upper and lower sides of the chain to be measured should be supported
3. Before measurement, the chain should be kept under the minimum tensile load of one-third and stay for 1 minute
4. During measurement, apply Add the specified measuring load to tighten the chain on both sides, and ensure normal engagement between the chain and the sprocket
5. Measure the center distance between the two sprockets
Measure the chain elongation:
1. To remove the clearance of the entire chain, measure under a certain degree of pulling tension on the chain
2. When measuring, in order to minimize the error, measure at 6-10 sections
3. Measure the inner L1 and outer L2 dimensions between the rollers of the sections to find the judgment dimension L=(L1+L2)/2
4. Find the elongation length of the chain, which is compared with the limit value of the chain elongation in the previous item
Chain structure: It consists of inner chain links and outer chain links. It is composed of five small parts: inner chain plate, outer chain plate, pin shaft, sleeve, and roller. The quality of the chain depends on the pin shaft and sleeve.
Precautions
Before the rear derailleur is connected, the chain should be adjusted to the state of the smallest wheel to the smallest wheel. In this way, the chain is looser and easier to operate, and it is not easy to "bounce" after cutting.
After cleaning and oiling the chain, slowly reverse the chainring. The chain links coming out of the rear derailleur should be able to be straightened. If some chain links still maintain a certain angle, it means that they are not moving smoothly and are deadlocked, and should be adjusted. If any damaged chain links are found, they must be replaced in time. For chain maintenance, it is recommended to strictly distinguish between the three types of pins and use connecting pins.
When using a chain breaker, pay attention to the straightness so that it is not easy to distort the thimble. Use tools carefully to protect the tools and achieve good results. Otherwise, the tools are easily damaged, and damaged tools are more likely to damage parts. That is a vicious cycle.
