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Please feel free to contactus Parts Sea engineers or sales for help if you have no parts No.
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The crankshaft is mainly composed of the crankshaft front end (or free end), connecting rod journal, main journal, crank, balance block and crankshaft rear end flange (or power output end). The main shaft is pre-installed on the cylinder block, the connecting rod neck is connected to the large head hole of the connecting rod, and the small end hole of the connecting rod is connected to the cylinder piston. It is a typical crank slider mechanism.
The crankshaft of a car engine is installed inside the car's engine. Its main function is to convert the heat energy when the car engine's gasoline is burned into rotating mechanical kinetic energy through the connecting rod crank mechanism.
During the operation of the engine, the piston is exploded by the mixed compressed gas, pushing the piston to move linearly, and transmits the force to the crankshaft through the connecting rod, and the crankshaft converts the linear motion into rotational motion.
Therefore, the rotation of the crankshaft is the power source of the engine and the source power of the entire mechanical system.
Under large loads, bending moments and torques often change. The general damage forms are bending fatigue damage and journal wear. Therefore, crankshaft materials are required to have high rigidity, fatigue strength and good wear resistance.
The crankshaft needs to be made of very high-quality materials and undergo strict surface treatment processes. Generally, it is die forged from medium carbon steel and medium carbon alloy steel such as 45, 40Cr, 35Mn2, etc. In recent years, more and more ductile iron is used. After forging or casting, in order to improve the fatigue strength of the crankshaft and eliminate stress concentration, the surface of the journal needs to be shot peened, and the fillets must be rolled; in order to improve the surface hardness of the journal, it is also necessary to The surface is subjected to high-frequency quenching or nitriding treatment, and finally is finished. The crankshaft treated in this way has sufficient fatigue strength and rigidity to resist bending and torsion, and the journal has a large enough pressure-bearing surface and wear resistance.
The steel crankshaft mainly determines the quality of the crankshaft due to the steel material, and the processing technology and processing accuracy. Steel crankshafts generally use the fillet rolling process. The accuracy of the crankshaft industry is invisible to the naked eye.
Common forms of crankshaft damage include journal wear, cracks, ablation, bending, twisting, fracture, etc. Generally speaking, crankshafts that are severely ablated, cracked, or broken cannot be repaired and can only be scrapped; for crankshafts that are bent or twisted with excessive deformation, we can use pressure correction to repair them.
The fitting gap between the crankshaft journal and the bearing bush increases after wear: it may be because there is too little engine oil or there are hard abrasives in the oil, the engine oil has deteriorated and contains acidic substances, and the fitting gap between the journal and the bearing bush is too large or too small, making it difficult for the oil film to form , dry friction will cause early wear. When the crankshaft rotates, under the action of centrifugal force, the mechanical impurities in the engine oil are biased to one side of the oil hole and become abrasive, causing the journal to wear unevenly and produce taper.
Scratches or strains on the surface of the crankshaft journal: The lubricating oil in the oil pan is not replaced on time, causing large metal objects and other abrasive particles contained in the lubricating oil to mix into the gaps between the bearing bush and the journal, scoring and straining the friction surface. If the maintenance of the air filter is not done properly, the wear gap of the cylinder liner, piston and piston ring increases, and abrasive materials such as sand and impurities are sucked into the cylinder with the air and burned, then escape to the oil pan and circulate into the journal and bearing. In the matching gap.
Crankshaft deformation: The deformation of the crankshaft is usually bending deformation and torsional deformation. A crankshaft with excessive deformation will cause increased wear and tear of itself and connected parts, accelerated fatigue, crankshaft breakage and excessive mechanical vibration.
Crankshaft breakage: A crankshaft breakage also represents engine damage. Common breakage locations include the crank arm where two adjacent rounded corners of the journal meet, the oil hole of the connecting rod journal, etc.
Please feel free to contactus Parts Sea engineers or sales for help if you have no parts No.
tse@partssea.com | sales@partssea.com
The crankshaft is mainly composed of the crankshaft front end (or free end), connecting rod journal, main journal, crank, balance block and crankshaft rear end flange (or power output end). The main shaft is pre-installed on the cylinder block, the connecting rod neck is connected to the large head hole of the connecting rod, and the small end hole of the connecting rod is connected to the cylinder piston. It is a typical crank slider mechanism.
The crankshaft of a car engine is installed inside the car's engine. Its main function is to convert the heat energy when the car engine's gasoline is burned into rotating mechanical kinetic energy through the connecting rod crank mechanism.
During the operation of the engine, the piston is exploded by the mixed compressed gas, pushing the piston to move linearly, and transmits the force to the crankshaft through the connecting rod, and the crankshaft converts the linear motion into rotational motion.
Therefore, the rotation of the crankshaft is the power source of the engine and the source power of the entire mechanical system.
Under large loads, bending moments and torques often change. The general damage forms are bending fatigue damage and journal wear. Therefore, crankshaft materials are required to have high rigidity, fatigue strength and good wear resistance.
The crankshaft needs to be made of very high-quality materials and undergo strict surface treatment processes. Generally, it is die forged from medium carbon steel and medium carbon alloy steel such as 45, 40Cr, 35Mn2, etc. In recent years, more and more ductile iron is used. After forging or casting, in order to improve the fatigue strength of the crankshaft and eliminate stress concentration, the surface of the journal needs to be shot peened, and the fillets must be rolled; in order to improve the surface hardness of the journal, it is also necessary to The surface is subjected to high-frequency quenching or nitriding treatment, and finally is finished. The crankshaft treated in this way has sufficient fatigue strength and rigidity to resist bending and torsion, and the journal has a large enough pressure-bearing surface and wear resistance.
The steel crankshaft mainly determines the quality of the crankshaft due to the steel material, and the processing technology and processing accuracy. Steel crankshafts generally use the fillet rolling process. The accuracy of the crankshaft industry is invisible to the naked eye.
Common forms of crankshaft damage include journal wear, cracks, ablation, bending, twisting, fracture, etc. Generally speaking, crankshafts that are severely ablated, cracked, or broken cannot be repaired and can only be scrapped; for crankshafts that are bent or twisted with excessive deformation, we can use pressure correction to repair them.
The fitting gap between the crankshaft journal and the bearing bush increases after wear: it may be because there is too little engine oil or there are hard abrasives in the oil, the engine oil has deteriorated and contains acidic substances, and the fitting gap between the journal and the bearing bush is too large or too small, making it difficult for the oil film to form , dry friction will cause early wear. When the crankshaft rotates, under the action of centrifugal force, the mechanical impurities in the engine oil are biased to one side of the oil hole and become abrasive, causing the journal to wear unevenly and produce taper.
Scratches or strains on the surface of the crankshaft journal: The lubricating oil in the oil pan is not replaced on time, causing large metal objects and other abrasive particles contained in the lubricating oil to mix into the gaps between the bearing bush and the journal, scoring and straining the friction surface. If the maintenance of the air filter is not done properly, the wear gap of the cylinder liner, piston and piston ring increases, and abrasive materials such as sand and impurities are sucked into the cylinder with the air and burned, then escape to the oil pan and circulate into the journal and bearing. In the matching gap.
Crankshaft deformation: The deformation of the crankshaft is usually bending deformation and torsional deformation. A crankshaft with excessive deformation will cause increased wear and tear of itself and connected parts, accelerated fatigue, crankshaft breakage and excessive mechanical vibration.
Crankshaft breakage: A crankshaft breakage also represents engine damage. Common breakage locations include the crank arm where two adjacent rounded corners of the journal meet, the oil hole of the connecting rod journal, etc.