What are the causes of crankshaft journal wear? How do I check the wear of the crankshaft shaft diam

The radial clearance between the crankshaft journal and the bearing is small, which allows the crankshaft to rotate freely without openness and radial runout. If the radial clearance between the journal and the bearing changes, it will often cause early wear and damage of the crankshaft journal and the shaft, which will increase the engine working vibration, increase the noise, increase the fuel consumption and increase the accident. Damage to the crankshaft journal and bearing can take the form of scratches, wear, fatigue peeling, corrosion, and burning.

Excessive wear and tear is mainly caused by improper use of the car and untimely maintenance. For example, when the wear of the mating gap between the journal and the bearing increases, and the bearing cannot be repaired and replaced in time, the oil supply pressure decreases, which increases the shock load and leads to accelerated wear. Failure to clean and replace the engine oil on time will also cause abnormal wear and tear on the shaft journal.

It should be the poor oil quality, poor lubrication, low oil pressure, crankshaft bearing damage, and repeated parking of the vehicle are all reasons.

Torsional fatigue and flexural fatigue.

In the end, there must be a problem with the oil.

CrankshaftThe diameter of the journal and connecting rod journal is measured as follows. The diameter of the crankshaft journal and the connecting rod journal can be measured with an outside micrometer. Each journal measures two sections, each section measures the diameter of 23 positions, Qi Defeat records the diameter value of each measurement, and finally calculates the journal of the crankshaftRoundnessError andThe cylindricity is high and the tremor is highError.

The calculation method is similar to that for measuring cylinders. If any of the journals is severely damaged or the amount of uneven wear exceeds the limit values, the crankshaft is reground or replaced with a new one.

Crankshaft diameter considerations.

The lateral quantity of the crankshaft journal mainly includes the cylindricity, diameter, radial circular runout of the main journal, etc. The crankshaft controls the bus straightness of the journal and bearing on the joint working surface during work.

Parallelism is more important than controlling roundness, so the cylindrical tolerance is commonly used to control the roundness error of the journal at the same time, and the roundness tolerance is not specified.

Measuring the cylindricity of the journal also uses an outer diameter micrometer to measure the six values of the large diameter and the small diameter on the three cross-sections of the two ends of the journal (completely avoiding the journal fillet) and the middle (avoiding the oil hole), and mark the lower position, where the difference between the large diameter and the small diameter is 1 2, that is, the cylindricity error of the journal. The cylindricity error in the same direction, in which one end is quietly covered and the other end is small, or the two ends are large and the middle is small, is a local abrasion of the bearing.

should be strictly restricted.

The wear of the crankshaft shaft diameter is usually measured with an outer diameter micrometer. Two cross-sections are measured for each trapped shaft diameter, and the diameter of 2-3 points is measured for each cross-section, and the diameter value of each measurement is recorded. Finally, the roundness error of each shaft diameter of the crankshaft is calculated to make the large cylindricity error.

Summary. The reasons for the wear of the crankshaft journal are as follows:1

Poor lubrication: The crankshaft journal needs to be adequately lubricated when rotating at high speeds, and if the lubrication is poor, the friction will increase, resulting in journal wear. 2.

Poor oil quality: Using a poor quality oil or using it for too long can cause additives and lubricants in the oil to break down and lose their lubricating properties, which can lead to journal wear. 3.

Excessive loads: Crankshaft journals are subjected to enormous loads when rotating at high speeds, which can lead to journal wear if they are exceeded. 4.

Bad usage habits: Long-term high-speed driving, frequent rapid acceleration, sudden braking and other bad usage habits will lead to crankshaft journal wear. 5.

Bearing failure: Bearing failure can lead to journal wear as the bearing loses support and protection for the journal. 6.

Poor material quality: Poor material quality and insufficient hardness of the crankshaft journal can also lead to journal wear.

Hello, there are several reasons for crankshaft journal wear, which leads to this situation.

The cause of crankshaft shaft wear.

The reasons for the wear of the crankshaft sideboard journal are as follows:1Poor lubrication:

The crankshaft journal needs to be adequately lubricated when rotating at high speeds, and if the lubrication is poor, friction will increase, leading to journal wear. 2.Poor oil quality:

Using a poor-quality oil or an oil that has been used for too long can cause additives and lubricants in the oil to break down and lose their lubricating properties, which can lead to journal wear. 3.Overload:

The crankshaft journal is subjected to a huge load when rotating at high speeds, which can lead to journal wear if it exceeds its tolerance range. 4.Bad usage habits:

Long-term high-speed driving, frequent rapid acceleration, sudden braking and other bad habits will lead to crankshaft journal wear. 5.Bearing failure:

Bearing failure can lead to journal wear because the bearing loses support and protection for the journal. 6.Poor quality of materials:

Poor material quality and insufficient hard finish of the crankshaft journal can also lead to journal wear.

You send it out. **Can't open.

At the end of compression, the pressure of the gas in the cylinder mainly depends on which two.

The gas pressure in the cylinder depends mainly on two factors: the volume of the combustion chamber and the position of the pistons. Empty belt When the piston moves upwards, the volume of the combustion chamber decreases and the gas is compressed, which increases the pressure of the gas.

As the piston dissolves and moves downward, the volume of the combustion chamber increases and the gas is stretched, which reduces the pressure of the gas. Therefore, the gas pressure in the cylinder depends on the volume of the combustion chamber and the position of the piston.

Wear and tear on the engine crankshaft can be caused by:

Poor lubrication: When the lubricating oil is insufficient or the quality is not good, the crankshaft surface will be worn. This wear usually manifests itself as wear marks and corrosion.

Abrasive contamination: During operation, the introduction of external grinding hole scrapers (e.g. dust, metal chips, etc.) may cause wear on the crankshaft surface.

Incorrect installation: If the crankshaft is not installed correctly or the installation is unbalanced, it can also lead to wear.

Overheating: When an engine overheats, the crankshaft is also affected, which can lead to surface wear.

The pattern of crankshaft wear usually increases with the time of use. When the surface of the crankshaft begins to wear out, friction and heat increase, leading to faster wear. If the crankshaft is not repaired or replaced in a timely manner, it can cause more serious damage to the entire engine, eventually leading to engine failure.

Therefore, measures such as changing the lubricating oil regularly, keeping the engine clean, and installing engine components correctly can extend the life of the crankshaft.

The main cause of crankshaft wear is poor lubrication, or it can be caused by the engine running at high speeds for a long time. The crankshaft is a very important component in the engine. The crankshaft and connecting rod are the components that convert the up and down motion of the piston into rotary motion.

The small head of the connecting rod is connected to the piston, and the large head of the connecting rod is connected to the crankshaft.

The crankshaft will rotate, the crankshaft will be connected to the flywheel, and the flywheel will be connected to the gearbox, so that the power will be transmitted from the crankshaft to the gearbox, and from the gearbox to the half shaft, and from the half shaft to the wheel.

Under normal conditions, there is no significant wear on the crankshaft. If there is obvious wear and tear, it is caused by poor lubrication.

There is oil in the engine. When the engine is running, the oil will be short-lived to form a layer of oil film on the surface of each component in the engine, which can avoid the friction caused by direct contact between the parts.

If the oil does not form a stable film, it will exacerbate engine wear.

The performance of the engine oil will deteriorate after a long period of use, and the oil needs to be changed regularly.

If you don't change the oil for a long time, it will increase the wear and tear of the engine.

Replace the oil filter element with each oil change. The oil filter is used to filter the oil. If there is no oil filter, the oil will be very dirty after using it for a period of time, which will also affect the normal lubrication of the oil.

Millions of car purchase subsidies.