Causes and solutions of bearing damage of hot oil pump
First, the thermal oil pump bearing overload-overload.
Solution: reduce load or redesign--if the system is constantly overloaded, try to re-select the bearing; short-term system overload and impact load can be solved by improving lubrication and special bearing treatment.
Hot oil pump
Second, the bearing of the hot oil pump bears excessive temperature and overheating-this is a performance. Just like "fever."
The sign is that the raceway, the ball and the cage change color, from gold to blue-mild lubricant discoloration, and even adhere to the raceway or roller. Severe bearing parts are blue and discolored. Heavy metal flow occurs in bearing components.
The temperature exceeds 400F to anneal the raceway and rolling element materials-this means the effect of high temperature on the mechanical properties of the bearing.
Reduced hardness leads to lower bearing load and early failure-bearing raceway or roller hardness lower than HRC58, life will be reduced.
Solution: The bearing operation must have a lubricant above a certain operating viscosity; temperature rise will reduce the viscosity of the lubricant and even affect its basic chemical properties.
Third, the false cloth dent of the heat transfer oil pump bearing-"false Brinell indentation".
The oval wear dents produced at each ball position are smooth, with obvious boundaries, and there is grinding around them--the shape is not always necessary. Such damage generally has no grinding marks in the indentation.
Solution: Vibration isolation and use of anti-friction additives-generally caused by flutter during transportation.
Fourth, heat transfer oil pump bearing Brinell hardness indentation-"true Brinell indentation".
occurs when the load exceeds the elastic limit of the raceway-generally caused by radial impact load.
The dent on the raceway increases vibration (noise)
Solution: Any static overload and severe impact will produce cloth dents-this kind of damage generally still has grinding marks in the indentation.
Fifth, normal fatigue failure-fatigue damage.
The fatigue failure of the hot oil pump bearing refers to the cracks on the raceways and rolling elements, and subsequent material fragments fall off-including fatigue cracking and fatigue peeling.
This kind of fatigue occurs gradually, once it starts, it expands rapidly, and is accompanied by a significant increase in vibration-hardened steel generally expands rapidly, which is easy to cause instantaneous damage. Carburized steel will have a longer period of development.
Solution: Replace bearings, and design bearings with longer fatigue life-choose bearings with higher dynamic load ratings, bearing steels with higher purity, and so on.
Sixth, hot oil pump reverse load-abnormal load.
Angular contact bearing is designed to only accept axial load in one direction
When the direction is opposite, the elliptical contact area of the outer ring is flattened
The result is increased stress, increased temperature, and increased vibration and early bearing failure
Seventh, the internal contamination of the heat transfer oil pump bearing is foreign matter.
Pollution is one of the main reasons for bearing failure
The sign of contamination is a little mark on the surface of the raceway and rolling elements, resulting in increased vibration and wear
Solution: Clean the environment, tools, and standardize operations. Storage and transportation of new bearings.
Eighth, the lubricating oil in the bearing of the heat transfer oil pump fails-lubrication failure.
The discoloration (blue, brown) of the raceways and rollers of the heat transfer oil pump bearings is a sign of lubrication failure, and then the raceways, rollers and cages wear out, leading to overheating and serious failures. --In the early days, there were slight glass-like scratches on the surface of the raceway.
The normal operation of rolling bearings depends on the existence of a good oil film between the components
Failure is often caused by insufficient lubrication and overheating-there can be two reasons for wrong lubrication (too much lubricant, too little, too silk, too thin) and ineffective lubrication (wrong lubrication method, oil cut, not timely replacement) .
Ninth, the heat transfer oil pump is out of alignment for a long time-eccentric load.
The sign of misalignment is that the wear marks produced by the balls on the raceway are not parallel to the edge of the raceway.
If the misalignment exceeds 0.001in/in, abnormal temperature rise of the bearing and bearing seat will occur, and cage ball wear--different bearing types have different allowable eccentric loads. Generally, self-aligning bearings have the best eccentric load capacity. However, other bearings can achieve the purpose of increasing a certain eccentric load capacity by optimizing the geometric dimensions of the raceway.
Tenth, corrosion-a kind of foreign matter entering, water.
The symptom is the appearance of reddish-brown areas on raceways, rollers, cages or other locations-early rust color, usually black.
The reason is that the bearing is in contact with corrosive fluids and gases
In severe cases, corrosion causes early fatigue failure of bearings
Solution: Eliminate corrosive fluids and use integral sealed bearings as much as possible-sealed bearings are not the first choice. Every bearing has its sealing system, the key is to make it effective.
