Burning tile refers to the relationship between the main shaft of the crankshaft and the bearing bush. The bearing bush or the connecting rod journal and the connecting rod are lubricated due to lack of oil lubrication, or the gap is too small to cause the oil film to rupture. The bearing pad and the journal surface are in direct contact, and dry friction occurs. Caused by salary or even death.
1. the reason
(1) Lack of oil. The oil pump fails, the oil pressure of the bearing bush is insufficient; the oil passage is clogged, the filter or filter is dirty, blocked, and the bypass valve fails; the bearing assembly is too tight or the bearing bush is too short, the bearing housing rotates, the oil passage is blocked, etc., causing the bearing bush Burning tiles occur in the absence of lubricating oil.
(2) The clearance between the bearing bush and the journal is too large, the pressure of the oil film is small; the clearance of the bearing bush is too small, or the bearing of the bearing bush is too high, the alloy at the mouth of the tile is deformed, and the area of direct contact between the two friction surfaces in operation is much larger than the specified value, so that the friction The heat is sharply increased, etc., causing the bearing bush to burn out.
(3) The roundness and cylindricity of the crankshaft journal exceed the tolerance and the oil film cannot be formed.
(4) The crankshaft is bent or the main bearing bore bearing bush is not too strong.
(5) The engine is overloaded for a long time and the engine is overheated.
(6) No lubricant is applied to the surface during assembly.
2. Method of exclusion
After the tile is burned, the bearing pads must be replaced and the crankshaft journals must be ground. The bending of the crankshaft, the bending of the connecting rod and the concentricity of the main bearing housing bore of the crankshaft should be checked. If the allowable value is exceeded, corrections and repairs should be made.
3. prevention
It is to start from the cause of burning tiles, to ensure good lubrication work, and to strictly comply with technical standards and operating regulations to assemble the bearing bush.
