The reason for the connection between the hollow shaft of the mill and the broken flange of the bolt and the handling of the Wang Guoying Guo Hongyuan Henan Province Qiligang Cement Plant 452370 mill is the main equipment of the cement enterprise, occupying an important position in the cement production, the central drive mill hollow shaft and The barrel flange coupling bolt breaks when it occurs. The bolt-breaking problem occurred in the center-center drive mill of our factory. It is understood that such bolt breaks have also occurred in Other cement plants. The hollow shaft of the central drive mill and the flange of the cylinder flange are the most critical parts of the mill. They play an important role in supporting the mill barrel, the whole weight of the grinding body and the material, and the transmission torque of the mill. It must be stopped and repaired, and the maintenance period is long and difficult, which seriously affects production. Now combined with the situation of our factory, the analysis and treatment of the breakage of the hollow shaft of the central drive mill and the flange of the cylinder flange are briefly summarized.
When the bolt breaks, the hollow shaft of the grinding head and the flange of the cylinder flange are connected to the bolt, and the bolt is broken. Because there is no spare part, the load is temporarily reduced, and the fitting is actively prepared. After a few months, when the bolt was stopped and replaced, it was found that the two bolts adjacent to the bolt were broken. In addition, several bolts that were not adjacent were also broken. The bolts were mainly hinged bolts. Followed by ordinary connecting bolts, most of the bolts break at the weak part of the joint of the head and roots, and the individual bolts break in the middle of the thread. The fracture is grayish white, with a small crescent shape, the section is bright and flat, and the plastic deformation marks are not obvious. It is a typical bolt material that suffers from fatigue due to excessive load and causes the fracture at the most severe stress concentration. Year, 13.2, 7+1. For example, 1 powder throwing Leng Bing Yin raw material throwing also found that the hollow shaft and the cylinder flange connection bolt break, most of the broken bolts with, 3.5 melon; 1 dried raw willow, 1 condition The buckle has a cut surface of 45 with the fracture, and the section is bright and grayish white. The bolt surface has obvious crush marks. In 1999, during the repair and 3.81 cement grinding process, it was found that the hollow shaft of the strip and the flange of the cylinder flange were broken. According to the running condition of the mill and the center line of the mill and the main reducer measured by the weft gauge, it is found that the deviation of the center line of the mill and the main reducer exceeds the allowable deviation range, which is greatly broken with the breakage of the joint bolt. Analysis of the cause The deviation of the center line deviation between the mill and the main reducer is the main cause of bolt breakage.
The hollow shaft of the central drive mill and the flange of the cylinder flange are subjected to alternating loads during the operation of the mill. If the deviation between the center line of the mill and the main reducer exceeds the allowable range, the torque of the mill increases, and the load on the bolts increases. During the running period, the bolts are fatigue cracked.
Bolts with large bolt load and uneven load are prone to breakage.
There is no stopping device at the time of manufacture. When the bolt is tightened, the bolt is not tightened evenly, and the bolt is unevenly stressed. In the installation and maintenance, the torque wrench is not used as required, the bolts are tightened, and the tightening torque is achieved. Instead, the self-made soil wrench is used to lengthen the steel pipe, and several people are tightened at the same time to clamp the tightening torque. Due to the feeling and experience, it is not guaranteed that the tightening torque of the bolt is even and tight, which does not guarantee evenly the bolt. At the same time, after the grinding machine is running for a fixed time, it can be tightened several times to meet the requirements. However, so far, normative installation and maintenance have not attracted widespread attention, and stress concentration is a common cause of stagnation.
Stress concentration is common in broken bolts. Mainly now, when machining bolts, the rounded corners of the bolts are only too small, even without rounded feet, resulting in stress concentration. When turning the crepe, the feed is unreasonable, the roots of the threads protrude sharply, resulting in stress concentration, and the hinge bolts are installed. When hammering is required, if the hammering point is not correct, the bolt head is skewed, causing the unilateral force to be applied, and the stress concentration at the root of the bolt is intensified. When the boring hole is machined, the boring chamfering is not performed, and the boring hole is not plucked. The edge of the circumference of the back cover protrudes, which aggravates the stress concentration at the root of the bolt. Compared with the defects of the processing method and method of the bolt hole, the axis of the hinge hole is not perpendicular to the end surface of the end cap, which causes the bolt head to be unilaterally stressed. The stress at the root of the stalk is concentrated. In the above aspects, the stress concentration of the bolts is generated or aggravated, resulting in the fracture of the Guigui.
The hardness of the bolt after heat treatment is insufficient, causing the bolt to break.
The material of these bolts is 4, and the hardness after the quenching and tempering treatment is required to reach HB277302.43.2X7+1.8m. The broken bolt surface of the grinding and drying raw material mill has obvious crushing marks, and the bright broken bolts are quenched and tempered. Hardness; 5, to meet the requirements.蹿阼 Received a powerful change! The variable fatigue treatment measures the center line deviation between the mill and the main reducer. The deviation between the center line of the mill and the main reducer is within the allowable range, preventing the mill from vibrating during operation and making it run smoothly.
Re-trim and ream the bolt holes. And ensure that the axis of the hinge bolt hole and the axis of the mill end cover prevent the bolt head from being unilaterally stressed and reduce stress concentration.
Replace the new one. Choose the skill level. Reputable manufacturers add new bolts, choose 4, materials, bold hinge bolt diameter, electric original, 58 oil increased to 358.51 匪, strict processing technology and quality requirements, emphasizing 1 quality buried, reducing snail roots and蟛4 roots; force centralized installation, measure the hinge bolt holes to prepare corresponding hinge bolts, prevent single-sided stress, reduce stress concentration, properly tighten and lock nuts in 33.51 unloading raw material grinding end cover A welding stopper is added around the bolt hole on the back to prevent the bolt from being tightened when the bolt is tightened. Since there is no torque to pull the private, the length of the steel pipe for the self-made wrench, the force and operation method are strictly regulated. After the back nut and the lock nut of the double nut locking device are tightened, the lock nut is slightly loosened to ensure the lock locking effect of the nut, and after the grinding machine is running for 8 hours, the tightening is re-tightened until the twist Until the tightening torque is constant, the bolts are kept in a good tight state, preventing the bolts from loosening and breaking, and ensuring the normal operation of the bolts.
After treatment, the center of the transmission mill of our factory is stable. The hollow shaft and the flange flange of the cylinder are not re-inquiring, which improves the operation rate of the mill. Sino-Australian joint venture Shanghai Aoenka Electric Co., Ltd. saves energy and saves worry. New 1 Ge energy-saving device 1 series static phase-in phaser Hai'ao Enka Electric Appliance Co., Ltd. is a company specializing in the production of new generation of energy-saving products series static phase advancer. Since it was put into the market in 1993, the product quality is stable and the reputation is good. It is trusted by the majority of users in the national cement, textile, coal mine and other industries. In particular, Zhejiang, Jiangsu, Anhui, Guangxi, Shandong, Hebei, Hubei, Gansu, Fujian, Guangzhou, Xinjiang and other regions have been widely used.
Series, ± phase phaser full-range reactive power random on-site compensation device, from the structural design to the electrical performance parameter matching can completely replace the rotary camera. It adopts cabinet structure, has frequency conversion technology and easy to adjust parameters, is not afraid of dust, has long service life and convenient maintenance. It is suitable for power factor compensation of high and low voltage wound-wound motors of different specifications. When the stator current is reduced, the power factor can be increased to above 0.98, and the energy saving effect can be up to 3. The Hall current sensor signal is used for sampling. The function of over-pressure loss protection and automatic conversion does not affect normal production, and is an ideal energy-saving product for motor users.
The series of static 1 phase phaser produced by the company. Yes, the minimum power of the wirewound motor is 1胤. The most human power is 20, also, the phaser model is adapted to the motor motor power, rotor current
Gabion Basket are made of hexagonal Galvanized/PVC/Zinc-Al double-twisted steel wire mesh. Double twisted hexagonal mesh Gabion& Reno Mattresses are commonly used for channel linings, river training, soil retention, slope stabilization.
Some of the advantage offered by Gabion Baskets are flexibility, durability, strength, permeability, ecology, reliability, longevity, low cost and an aesthetic.
Gabion Baskets
Gabion Baskets,Military Gabion Basket,Gabion Stone Baskets,Professional Gabion Baskets
Hebei Giant Metal Technology Co., Ltd. , https://www.wiremesh.pl