1： Bearing grease rheology:
1. When the grease is not affected by external force, it can maintain a On Ina Bearing certain shape like a solid, that is, it will not lose automatically at rest.
2. Under the condition of extremely high shear stress (large shear speed), the flow of lubricating grease is like Newtonian fluid, and the viscosity can maintain a constant without changing with the change of shear speed.
3. Elastic deformation occurs On Ina Bearing when subjected to weak external force; After removing the external force, it can return to its original position and shape, showing the elastic properties of the solid.
4. When the applied external force is large enough, the grease deforms and flows, so it can no longer automatically return to its original position and shape. On Ina Bearing Therefore, the starting torque of the grease on the mechanical running parts is greater than that of the liquid lubricant.
The ambient temperature is high and the grease lubrication is not suitable. At present, the molybdenum disulfide grease used for forging the INA Bearing of mobile bomb is considered to be high-temperature resistant grease. We know that its base oil is petroleum products.
Add a small amount of high-temperature resistant molybdenum disulfide additive, and its temperature resistance limit is 120 ℃. Moreover, there are more than 30 oil filling points of the whole machine. This On Ina Bearing cumbersome oil filling operation cannot be realized for long-term operation and maintenance.
Therefore, it is necessary to pour the thin oil pot on the outside of the running bearing sleeve. It is difficult for the lubricating oil to enter the friction pair of the On Ina Bearing bearing, and most of the bearings are in the friction state.
It is measured that the working temperature of INA Bearing of forging machine can reach 200 ℃, which has far exceeded the temperature resistance limit of lubricating grease.
Under the premise of such high temperature, the base oil in the lubricating grease will become thin and evaporate gradually, and the remaining carbon slag, molybdenum disulfide and dust will be mixed into solid blocks and solidified on the cage of the movable bearing, which will not only lose its lubricating effect,
but also hinder the normal operation of the movable bearing and wear quickly. It will have to shut down for more than 2 weeks, remove the bearing, clean and replace the grease.
The self-lubricating ina bearing has wide service temperature, sufficient solid lubricating material content and average release. It On Ina Bearing has good self-lubricating function and bite, which can effectively protect the journal and achieve the purpose of lasting use.
1. Contact fatigue failure
Contact fatigue failure refers to the failure caused by alternating stress on the working surface of IKO imported bearing. Contact On Ina Bearing fatigue spalling occurs on the working surface of the bearing and is often accompanied by fatigue cracks.
It first occurs from the large alternating shear stress below the contact surface, and then extends to the surface to form different spalling shapes, such as pitting or pitting spalling, which is called shallow spalling.
Due to the gradual expansion of the spalling surface, it often expands to the deep layer, forming deep spalling. Deep spalling is the fatigue source of contact fatigue failure.
2. Wear failure
Wear failure refers to the failure caused by the continuous wear of the metal on the working surface caused by the relative sliding friction between the surfaces. Continuous wear will cause gradual damage to bearing parts, and eventually lead to the loss of dimensional accuracy of IKO imported bearings and other related problems.
Wear may affect the change of shape, the increase of fit clearance and the change of working surface morphology, may affect the lubricant or make it polluted to a certain extent, resulting in the complete loss of lubrication function, so that the bearing loses the rotation accuracy and even cannot operate normally.
Wear failure is one of the common failure modes of various bearings. According to the wear form, it can On Ina Bearing be divided into common abrasive wear and adhesive wear.
1) Instrument detection
It is only a convenient and reliable method to judge the running state of the bearing and whether it should be maintained or replaced by using a Ferrograph or SPM or a new vib05 detector.
For example, when using vibo5 detector, which is a newly designed machine state detection instrument based on microprocessor, it has the functions of vibration detection, IKO imported bearing state analysis and infrared temperature measurement.
It is easy to operate and On Ina Bearing automatically indicates the state alarm. It is very suitable for on-site equipment operation and maintenance personnel to detect the state of the equipment, find problems in time and ensure the normal and reliable operation of the equipment.
Using such an instrument can make full use of the working potential of the bearing, guarantee the bearing in time, and avoid faults. It is more suitable for young workers to make up for their lack of experience.
2) Manual detection
In places where the above instruments are not available, monitoring tools modified by equipment similar to medical stethoscope can be used for detection.
Experienced operators can also use tools such as round rods or wrenches to collide with the parts of the machine shell close to the bearing and use their ears to monitor the running sound of the bearing through the tools.
The normal running sound of IKO inlet shaft should be uniform, stable and not harsh, while the abnormal bearing running sound is intermittent, impact or harsh.
This method is suitable for experienced staff to operate, which mainly depends on the accumulation of staff experience.