Causes and solutions of the most popular fracture

Causes and solutions to the fracture of the imprint connecting rod

js2102 split double-sided offset printing machine, mainly engaged in book printing. Its advantage is that it can complete the double-sided printing of books and periodicals at one time, and the speed is fast. It is an important machine and equipment for book printing

js2102 printing machine during a normal printing, the operator found that the machine could not operate normally, and sometimes the car did not move. After I went, I first asked the electrician to check the electrical appliances and the main engine motor, and there was nothing wrong. Then I used the crank to shake the car manually, and I obviously felt that the machine was too heavy. Also check the transmission belt of the main engine motor. It is found that the belt is too loose. After adjusting the tightness of the belt, press the running switch and the machine will run. After 2 minutes, the machine will stop automatically (like biting)

open the protective cover of the oil tank on the operating surface, feel it with your hand, and find that all parts are normal, while the lower rubber roller bearing sleeve is hot. It is preliminarily judged that the heating may be caused by the lack of oil in the roller bearing

check 1: first pull out the eccentric bearing sleeve of the drum and check the oil circuit. No blockage of the oil circuit and seizure of the bearing sleeve are found. Open the oil pump smoothly. In order to prevent the roller bearing sleeve from slightly tight fit with the roller shaft, I used a scraper to scrape the bearing sleeve, which has many beneficial conditions for the export of China's extruder industry. After being installed, it ran, and then it still stopped after 2 minutes. Touching the bearing sleeve by hand is still hot

inspection 2: open the oil tank protective cover on the transmission surface, feel the inner side of the transmission gear of the lower rubber drum slightly warm by hand. Considering that the eccentric bearing sleeves on both sides of the drum are not synchronized, it will also cause the bearing seizure phenomenon. If the machine moves horizontally, it will also cause this phenomenon, so I use water like a level gauge to check, and the machine level is also normal

inspection 3: loosen and unscrew the set screw on the transmission gear of the drum transmission surface when the rubber testing machine is often used, pull out the small bag packaging for other condiments, and then pull out the position pin, and use the special pulling code (pulling the bearing sleeve tool) to pull out the transmission gear. It was found that the imprinted connecting rod on the eccentric bearing sleeve of the drum inside the transmission gear on the transmission surface of the lower rubber drum was broken

analysis: the reason for the heating of the eccentric bearing sleeve and the seizure failure during the operation of the machine is that the eccentric bearing sleeve of the drum on the operating surface has been completely released from pressure (the eccentric sleeve has been released from pressure in place) after the normal printing of the machine. The transmission surface is not completely off pressed (not in place) because the imprinted connecting rod is broken during off pressing. This will cause the eccentric sleeves at both ends of the lower rubber drum not to be in the same position, which will increase the load of the main motor of the machine, increase the current, manually shake the car too heavy, and finally stop the machine after being bitten due to the heating of the bearing sleeve

after finding out the fault, replace the new imprinted connecting rod, adjust the eccentric bearing sleeve at both ends of the drum, and operate after startup. Everything is normal

there are several reasons for this situation:

1. During long-term normal printing, the machine frequently imprints and disengages, causing excessive fatigue of the imprinting connecting rod, resulting in the fracture of the connecting rod

2. The pressure of the embossing cylinder is too heavy, which makes the connecting rod fatigue

3. When feeding paper, the electric teeth are out of control and do not work, causing a stack of paper (varying in number) to leak down at the same time, causing the drum to die. At this time, the embossing connecting rod can also be broken due to excessive force

4. the eccentric bearing sleeve of the drum is seized due to lack of oil

5. During the normal high-speed operation of the imprint cylinder, it is also easy to cause the fracture of the imprint connecting rod by squeezing screws, wrenches, etc

there are clamps at both ends of the operating spline. More attention should be paid to the above aspects to avoid the fracture of the imprinted connecting rod