Abstract: This article will analyze and explore the main strategies for preventing damage to sliding bearings, hoping to provide some help and suggestions for relevant personnel to better avoid damage to the sliding shaft.
Keywords: injury prevention; Sliding bearings; Mechanical vehicles
Introduction
When a sliding bearing is in working condition, friction occurs between the bearing shell and the journal due to contact with each other, resulting in various situations such as wear, heat, and seizure on its surface. The specific damage content includes corrosion of the bearing surface, corrosion of the journal surface, pulling of the journal surface, micro wear of the back of the bearing, pulling up of the bearing surface, peeling of the bearing surface, burning of the bearing, and wear of the bearing. Therefore, Studying the main strategies for preventing damage to sliding bearings has certain practical significance.
1. Reasonably assemble and repair bearings
Staff should strengthen the work of hinge fitting bearings, improve the quality of hinge fitting, and ensure that there are no spots on the back of the bearings, exhibiting smooth characteristics and having very complete positioning protrusions. The opening amount of the bearing should be reasonably set to ensure that after assembling the bearing, the bearing shell can tightly fit the bearing seat hole using elastic force. The protrusion of the upper and lower bearing shells of the bearing seat should be determined based on the actual situation, so that they can tighten the bearing cover bolts according to the torque requirements, so that the bearing seat and bearing are closely matched, forming a large amount of frictional self shrinking force. If the bearing is very tight and has strong heat dissipation, its wear and erosion prevention effect will be better [1]. At the same time, during the assembly process of bearings, it is necessary to strengthen the inspection of crankshaft bearings and journals, strictly follow the repair specifications and process inspection, avoid various problems such as bearing bolts not meeting the requirements, uneven torque, and non-standard installation caused by incorrect installation methods, and prevent bearing damage caused by stress concentration, bending deformation, and other situations.
2. Proper use of bearings
Firstly, when in low speed and heavy load conditions, try not to let the engine work for a long time as much as possible. Under low speed and heavy load conditions, the bearings of the engine will reach a state of boundary lubrication, especially after the engine reduces the speed to the vibration point. Due to the influence of vibration waves caused by vibration, different metals are prone to contact each other. To ensure a longer service life of the bearings, it is necessary to control the speed as much as possible when the engine is in low speed and heavy load conditions.
Secondly, if the bearing is very lacking in lubricating oil, excessive and extensive wear may occur, and sometimes it can also lead to shoe burning. From this, we can see that when using machinery, workers need to regularly inspect the oil level of the oil pan, and if the height is not enough, it needs to be added. When using machinery, workers need to conduct regular checks on the quality of lubricating oil. Generally speaking, during the use of lubricating oil, it will gradually deteriorate, mainly due to fuel dilution and mechanical impurities pollution. When lubricating oil depreciates, it will greatly reduce its lubrication effect and bring varying degrees of harm to machinery. This requires staff to regularly conduct comprehensive and detailed inspections of the quality of lubricating oil, and replace it if necessary.
3. Timely adjustment and inspection of bearings
The inspection of bearings mainly includes disassembly inspection and non disassembly inspection. Among them, non disassembly inspection refers to auscultation work based on the experience of staff or corresponding equipment and the sound emitted without dismantling the machine. If the bearing is damaged, there will be abnormal sounds during its operation, resulting in knocking sounds. For the main bearing, the knocking sound is relatively heavy, which will become louder and louder with the increase of load and speed, especially when the accelerator increases instantaneously, and the engine will vibrate. After the gap increases, the tiles burn, and the alloy falls off to a certain extent, there will be knocking sounds regardless of the load and speed. When determining the source of the bearing noise, the staff mostly make judgments based on their own experience, or make the front and rear cylinders of the bearing cut off. If the sound decreases at this time, it indicates that the noise emitted by the bearing is [2]. At the same time, compared with the knocking sound from the main bearing, the knocking sound of the connecting rod bearing is slightly lighter. When listening from the outside of the engine body, it is like the sound of a refractory brick being knocked by a small hammer. It is firm and short. To enhance the effect of auscultation, the staff can use the machine stethoscope.
Disassembly inspection is usually carried out simultaneously with bearing technical repair and maintenance, or after specific problems are identified through non disassembly inspection. The staff can effectively identify the condition of bearing damage through disassembly inspection work. When checking the clearance of the connecting rod bearing on the vehicle, the engine oil should be drained first, the connecting rod end cover and oil pan should be removed, and then the bearing should be taken out. If the wear reducing alloy does not have cracks, detachment, or burning, the impurity layer on its surface should be scraped off with the help of a scraper, and the oil holes and grooves should be corrected to show the new wear reducing alloy layer. Then, it should be reinstalled according to the disassembly steps, and the gap should be adjusted and checked.
4. Adjusting the design process
When designing and selecting bearings, consideration should be given to their thermal balance and temperature rise control should be done well. When in a frictional state, the bearing will experience some power consumption due to the friction generated inside the lubricating oil, which is prone to temperature rise when converted to heat. After the lubricating oil changes the clearance and reduces viscosity, the babbitt alloy in the bearing will soften, and in severe cases, safety accidents such as burning the bearing and holding the shaft may occur. It is not difficult to see from this that when designing the structure of the bearing, the oil inlet hole should be located at the top of the upper bearing shell, allowing lubricating oil to enter through the non load bearing area. When opening the oil groove, the oil inlet hole should be taken as the center and carried out horizontally or longitudinally along the inner surface of the bearing shell. This can make the lubricating oil distribute more evenly on the journal and play a controlling role in temperature rise.
According to the actual working condition of the bearing, the bearing material should have strong plasticity, mechanical strength, anti gluing ability, corrosion resistance, wear resistance, thermal conductivity, and small coefficient of thermal expansion and coefficient of friction. From this, we can see that babbitt alloy is a good choice for bearing material. If Babbitt alloy is used, it can work better when the load is stable, and cavitation is prone to occur when the load is unstable, so it is not suitable for application to high-power generators. In contrast, low tin lead based alloys and high tin lead based alloys have higher hardness, strength, cavitation resistance, and fatigue resistance, and can have good results when applied to high-power engines.
Epilogue
In summary, studying the main strategies for preventing damage to sliding bearings is of great significance. Relevant personnel should, based on the specific causes of sliding bearing damage, effectively eliminate sliding bearing faults through various methods such as reasonable assembly and maintenance of bearings, correct use of bearings, timely adjustment and inspection of bearings, and adjustment of design processes, so as to extend the service life of bearings and create more benefits.
More about Marginal Material Specification Sheet–MG-6:
Material specification sheet – MG-6 is Ball and roller bearing steel according to EN ISO 683-17. Ball and roller bearing steel for balls and rollers of any dimension,rings and discs up to 30mm effective thickness.
