What is the reason for the failure of the hydraulic retaining wheel bearing of the cement kiln?

The cause of damage may be the gap caused by vibration and the generation of stress.

At present, in view of the bearing damage, especially the wear and tear of some bearing positions and bearing chambers, the traditional disassembly repair welding brush plating method is often time-consuming and labor-intensive, and the thermal stress generated by the repair welding is difficult to eliminate, and the accuracy after repair often does not meet the requirements, and polymer composite materials are generally used for on-site rapid repair.

Cement rotary kiln belongs to the category of building materials equipment and is a kind of lime kiln. It belongs to the category of building materials and equipment, and is a kind of lime kiln. Rotary kilns can be divided into cement rotary kilns, metallurgical chemical rotary kilns and lime rotary kilns according to different materials processed.

The hydraulic retaining wheel is used to control the axial movement of the rotary kiln body, so that the wheel belt and the supporting wheel can be evenly worn on the full width, and at the same time, the straightness of the kiln centerline can be ensured, so that the large and small gears are well meshed and the power consumption can be reduced [1]. With the large-scale rotary kiln equipment, the influence of hydraulic retaining wheel on the stable operation of rotary kiln is becoming increasingly prominent. After the problem of the retaining wheel device, the rotary kiln will reduce production and slow down the operation, and the kiln will be stopped for maintenance.

Now the causes of the failure of the hydraulic retaining wheel of the rotary kiln are analyzed from four aspects: design, manufacturing and assembly, installation and commissioning, use and maintenance, hoping to help the designers, manufacturers, installation companies and manufacturers of rotary kilns. 1. Design problems: Because the design institute improves and optimizes the design and the equipment production is not synchronized, it will cause the same problem to occur repeatedly in the production process of the equipment manufacturer. (1) Lubrication of retaining wheel bearings.

The main bearing of the retaining wheel of some design institutes is lubricated with extreme pressure lithium grease, and the bottom bearing is lubricated with thin oil. Because the main bearing bears a large alternating stress, when the lubrication condition is poor, the main bearing is easy to be damaged due to the lack of lubricating oil, resulting in the failure of the hydraulic wheel retaining device. Some manufacturers increase the oil level of the lubricating oil, so that the main bearing is also lubricated with thin oil, the lubrication effect is better than grease lubrication, and the temperature of the main bearing is also lower [2].

2) a design institute rotary kiln retaining wheel adopts a double row radial roller bearing and a thrust spherical roller bearing, due to the large spacing between the two bearings, resulting in the rigidity of the retaining wheel shaft is not enough, and the retaining wheel bearing is subjected to huge alternating stress, and fatigue fracture occurs at the shaft diameter transition.

The hydraulic retaining wheel bearings of the rotary kiln belong to the design of slow speed and high load, and are currently imported bearings such as FAG or SKF, with a design service life of 50,000 hours.

But from the actual situation, due to the change of kiln working conditions caused by the hydraulic retaining wheel from time to time there is a large load (hydraulic pressure more than 12MPa), so it may be damaged in about 3 4 years of use, due to the influence of noise and other aspects of the site, it is difficult to judge at the beginning of the failure, when the retaining wheel appears no rotation and other abnormal phenomena, the bearing has been seriously damaged, and generally has caused damage to the shaft and the shaft sleeve, so that the inner ring of the bearing and the main shaft, the outer ring of the bearing and the sleeve are stuck, and the difficulty of maintenance work such as assembly and disassembly is increased, so that the kiln shutdown time will be greatly prolonged. According to the normal maintenance time, the replacement of hydraulic wheel bearings can be completed in 1 2 shifts, but after the bearing spindle or shaft sleeve is stuck, it will take 3 to 4 days to resume production.

According to these circumstances, we arrange to check the clearance, raceway, rollers, etc. of hydraulic retaining wheel bearings that have been used for 20,000 hours when planning maintenance, and replace them once problems are found.

In order to minimize the abnormal downtime of the kiln, we arrange the dismantling and cleaning of the relief valve, reversing valve and other components during each kiln shutdown planned maintenance, and replace the rubber seals regularly, so as to avoid the failure of the kiln shutdown caused by damage to these components to the greatest extent.

The main fault is still the mechanical part, the electrical part is relatively stable, and the occasional stroke failure occurs.

There is no electrical failure, only mechanical failure, electrical appliances are generally the stroke limit switch has a problem, and the others are mechanical hydraulic control

What is the matter with the squeaky sound in the hydraulic retaining wheel of the rotary kiln - use the earpiece to slowly listen to which part is issued, if the sound is louder near the bearing, it is estimated that it is the problem of the bearing, and pay attention to the pressure fluctuation of the retaining wheel, which is normal at 2-5MPa, and it should be paid attention to when it is big. But don't worry, as long as you observe carefully, there is enough time for you to observe slowly, because the damage of the bearing requires a process, and it is important to pay attention to whether the lower thrust bearing at the bottom of the retaining wheel and the end cover bolt are broken.

And do I need to add lithium grease in the guide shaft frequently? ——It is best to add it often, according to the requirements of the manual, generally a week or half a month.

If you are often oiled and maintained, pay attention to dust. The resounding is a quality problem, and the technology of many companies that produce support wheels cannot meet the requirements.

If the rotary kiln is too long, multiple gear wheels are required. It also has a lifespan. It is best to replace it to a certain lifespan.

The working principle of the hydraulic retaining wheel.

The hydraulic retaining wheel device is mainly composed of a retaining wheel, an oil cylinder, an oil station and the like, as shown in the figure (shown: the pressure oil produced by the speed regulating motor 1 drives the fuel injection pump 2, passes the check valve 4, the speed regulating valve 5, the solenoid spool valve 6, enters the oil cylinder 7, and the cylinder body moves up by pushing the retaining wheel 8 and the roller ring by the piston. When the cylinder moves up to the upper limit position, the travel switch 11 sends out a signal, and the drive motor 1 stops, and the solenoid spool valve 6 changes the working position; Because the oil cylinder is a single mode of action, the cylinder body moves down by the sliding force generated by its own weight at this moment, pushes the stop wheel to reset the piston, and the pressure oil in the oil cylinder flows back to the oil tank through the solenoid slide valve 6, the speed regulating valve Qiao 15.

When the cylinder moves to the lower limit position, the travel switch 12 sends out a signal, starts the driving motor 1 to work again, makes the solenoid slide valve 6 reversible, and the retaining wheel starts to push the cylinder to move up again, repeats the above-mentioned process. The speed of cylinder moving up and down is controlled by two independent speed regulating valves 5 and 15 respectively. The oil that exceeds the pressure set value flows back to the oil tank 18 through the relief valve 16 during the operation of the hydraulic system.

The oil transfer pump 3 overcomes the resistance of the fine filter 17, and the oil is supplied to the fuel injection pump.

Due to the self-weight of the rotary kiln and the inclination angle, after its rotation, there is a downward movement (downward) along the direction of the rotary kiln cylinder. Assuming that there is no hydraulic stopper, such an unrestricted downward movement of the equipment will not operate normally. That's where the hydraulic stopover wheel comes in.

When the cylinder is lowered to the lower limit position, the oil pump is started and the cylinder is pushed up (up) by oil pressure. When the cylinder reaches the upper limit, the oil pump is shut down. The barrel is due to its own weight and with an angle of inclination.

Downlink! The rotary kiln moves again and again. This is the role of the hydraulic retaining wheel in the rotary kiln.

If you think it will work for you, give some bonus points! Hehe.

SKF bearings are optional. I'm SKF China Sales ****. Helped many customers solve related problems.

Adjust the supporting wheel to the upper push wheel, but how to adjust I don't have a specific operating standard is very rare, our workshop master, with experience to adjust. If the roller is not adjusted well, it will vibrate and heat up. If it's a new kiln in Handan, you can ask about it.

The kiln angle is too large and needs to be adjusted.

Retaining wheels are divided into two types according to their functions:

A kind of ordinary retaining wheel is used to indicate the axial movement of the kiln body, as a non-ferrous metal signal device in Dashan, Henan. So, how to disassemble such composite roller bearings? What are the commonly used disassembly methods?

For those who use these products regularly, knowing this will help to improve production efficiency. The fundamental requirements of the bearing for data are largely determined by the operating function of the bearing.

Another copper-based brass guide plate guide sleeve is made of high-strength brass material rolled by continuous casting and extrusion, which has a dense structure and few impurities to ensure excellent wear resistance; If inferior materials are used, the composition and mechanical properties cannot be guaranteed, and the organizational structure is poor, which directly affects the service life of the guide plate guide sleeve and the grinding parts. These special conditions are when rolling.

Orbit & Roll) is a smooth film layer that effectively separates and limits the damage that appears to be caused by non-ferrous metal contaminants in the mountains of Henan.

Do not rotate is also called the rest wheel, see how your kiln retaining wheel and the wheel belt are connected, the kiln rotates a circle of retaining wheel intermittently, indicating that your kiln cylinder is bent, or the contact surface between the supporting wheel and the wheel belt is poor, 2kiln channeling and so on.