What are the causes of crankshaft saffling? What is the cause of engine lava?

Answer: 1. Lack of oil, high temperature, blocked oil passage, and poor lubrication cause crankshaft shoeing.

2. The oil pressure is low or the oil pump fails, and the crankshaft is swayed due to poor lubrication.

3. The oil fails (the oil contains water or is too dirty), and the crankshaft is shoeed due to poor lubrication.

4. The speed is too high for a long time, overload operation, and poor lubrication cause crankshaft shoeing.

For some cars that have been used for a long time, or are not in good condition, it is common to hear about the phenomenon of engine slapping. Once this phenomenon occurs, the engine will be completely unable to run and the cylinder block must be disassembled for overhaul, which will cause huge damage to the engine and bring maintenance costs. So what exactly is a saga, what is the part of the "tile" that is pulled, what is the cause of the sva, and what are the signs of the engine before the sva?

Figuring out these issues will help us better protect the engine from happening. Tile is a colloquial name that gets its name from the fact that it is shaped like a tile on a roof. In fact, it is a sliding part between the crankshaft and the connecting rod, which, together with the oil, forms a plain bearing, like a rolling bearing on a two-stroke engine.

We know that there is no such thing as "rava" in two-stroke engines, mainly because two-stroke engines do not have tiles at all.

Reasons for Rava :

1. The engine oil itself has quality problems, poor load resistance and high temperature; Recommendation: Maintain the quality of the oil.

Second, the installation of large tile torque is wrong, too tight; Its contractual oil film is difficult to form; Recommendation: Use a torque wrench.

3. The opening difference of the main bearing is too large or too small; Inspect the crankshaft and main housing.

Fourth, the thrust bearing clearance is too large; Check the thrust bearings.

5. The oil pump is faulty or the flow rate is small; Check the oil pump.

Summary. Hello, this question can give you a perfect reply, wait for me to sort out the information, I'm typing, 2-3 minutes, don't finish.

Hello, this question can give you a perfect reply, wait for me to sort out the information, I'm typing, 2-3 minutes, don't finish.

Isuzu connecting rod bearing pulled 1 point crankshaft pad is not afraid of strain.

Hello, I am your exclusive technician, attentive, careful, dedicated to answering your car questions, for you to find the corresponding solutions and solutions to the problem of blindness! According to the reasons for your crankshaft sizing, the answers to the questions are as follows: First, the oil pressure is too low or the oil lubrication is not good. Second, the large tile on the crankshaft and the small tile on the crankshaft are caused by problems.

Auto Master is dedicated to serving you, and I hope my answer can help you!

The small vara is injured at 1 point, and the big tile is not afraid of injury.

The little vara hurts a little and needs to be replaced! Remove the tile and check it for strain!

Ask about custom messages].

1. The oil pressure is insufficient. If the oil pump gear is severely worn, the pump oil pressure is not enough. Or the oil pipeline leakage, the lack of oil pressure is not enough, and the oil is difficult to supply to the designated lubrication part, forming dry friction and slapping.

2. The oil passage of the engine is blocked by impurities, the oil is too dirty, the filter is blocked, the oil supply is not smooth, the oil circulation is not lubricated between the bearings, and the friction increases to form a shoe.

3.The engine working temperature is low, especially in winter, there is no preheating and heating, the oil is in a viscous state, and the oil can not be well circulated, so that the lubrication is reduced.

4.When the engine is replaced with bearings, the equipment is improper, and the gap between the bearings is large, which makes it difficult for the bearings to balance and form a layer of oil film, resulting in excessive friction and saddling.

5.The temperature is too high. There is a lack of oil or not enough oil, or the oil enters the fuel, or the oil and water mix, causing the oil to become thinner. Or water circulation leakage, water shortage, fan failure, etc., so that the engine working temperature is too high, resulting in the phenomenon of shoeing.

6.Vehicles are overloaded and loaded, etc., which can also cause Rava.

Speaking of the crankshaft of the automobile engine, we have to look at the force of the crankshaft of the automobile engine when it is working, it bears the force from the connecting rod, the centrifugal force of the rotating mass, the gas inertia force and the reciprocating inertia force of periodic changes. These forces overburden the crankshaft pads, which are also exposed to pressure, impact and friction.

Photo by Brother Choosing a Car) @2019

When it comes to automobile engine crankshaft bearings, we must first look at the force experienced by the crankshaft of the automobile engine when it is working. It is subjected to forces from the connecting rod and is affected by the centrifugal force of the rotating mass, the periodically varying gas inertial force, and the reciprocating inertial force. These forces overload the crankshaft pads, which are subjected to pressure, impact and enormous friction.

The reason for the tearing of the engine crankshaft is that from the above various unfavorable factors to the crankshaft bushing, it is necessary to have high quality requirements for the crankshaft and bushing. If the crankshaft and pads are not of good quality, there will be some failures. For example:

1.Insufficient oil pressure. If the oil pump gears are badly worn, the pump oil pressure is insufficient.

Or due to oil leakage and lack of oil in the oil pipeline, the oil pressure is insufficient, and it is difficult to supply oil to the designated lubrication part, resulting in dry friction hall. 2.The oil circuit is blocked by impurities, the oil is too early to call dirty, the filter is blocked, the oil supply is not smooth, the oil circulation is less than the lubrication between the bearings, the friction increases and the engine working temperature is low, especially in winter, there is no warm-up, the oil is in a viscous state, and the oil can not be well circulated, which reduces the degree of lubrication.

If you press the throttle hard, the temperature between the pads will rise instantaneously, causing the pad surface to be ablated. 4.The engine is not properly assembled when replacing the bearings, and the bearing clearance is large, which makes it difficult for the bearings to form a layer of oil film, resulting in excessive friction.

5.The temperature is too high. There is a lack of oil or insufficient oil quantity, or the oil enters the fuel, or the oil and water mix, making the oil thinner.

Or leakage of water circulation, lack of water, fan failure, etc. The operating temperature of the engine is too high, resulting in lava phenomenon. 6.

There is a shortage of oil or the oil pump is not working.

With mild lava, the engine can be operated, and the noise increase or shaking of the engine can be intuitively distinguished; If the crankshaft is locked and the crankshaft is severely staggered, the engine will not be able to rotate and work normally.

It depends on the severity of the lava, if it is just at the beginning, you can only change the bearing, if it is a period of time, the bearing has been relatively thin, it means that the crankshaft is looser when the engine is running for a period of time, which may cause the cylinder or piston to wear and even lead to the cylinder, so that the engine will have to be overhauled, which will be more expensive. In addition, it should be noted that the tiling is usually caused by insufficient lubrication due to insufficient oil, if the tiling is serious, it is best to check whether the lubrication system is normal and whether the oil supply is sufficient, otherwise the same problem may occur even after changing the bearings.

It's the crankshaft bearing.

Overview of crankshaft bearings.

The pads that are installed on the fixed brackets of the crankshaft and cylinder block and play the role of bearings are usually called crankshaft pads. General diesel engine crankshaft pad clearance: gasoline engine crankshaft pad clearance, the limit wear does not exceed.

Assembly requirements for crankshaft bearings.

The notches of the two tiles of the notch should be facing the same side, if the connecting rod bearing is special on both sides, the marking on the side of the connecting rod should be seen.

Bearing length. The new bearing is fitted into the housing bore and each end of the upper and lower pieces should be higher than the bearing seat plane. In order to ensure that the bearing pad and the seat hole are closely fitted, and the heat dissipation effect is improved. The best rule of thumb for checking the length of the bearing is:

The bearing is installed, the bearing cover is installed, one end bolt is tightened according to the specified torque value, and the gasket with thickness is inserted between the other end cover and the bearing seat plane, when the torque of the bolt at the end reaches 10-20N·m, if the gasket can not be extracted, the bearing length is too long, and one end of the non-positioning protrusion should be filed; If the gasket can be extracted, it means that the bearing length is suitable; If the gasket cannot be pulled out without screwing to the specified torque value, it means that the bearing is too short and should be re-selected.

The back is smooth and protruding.

There should be no spots on the back of the bearing, the surface roughness Ra is, the tenon can prevent the bearing from rotating, play a positioning role, if the tenon is too low, the ideal height can be impacted with the tip, if the tenon is damaged, the bearing should be re-selected.

Elasticity is suitable without mute.

After the new bearing is put into the bearing seat, the radius of curvature of the bearing is required to be greater than the radius of curvature of the housing hole, and when the bearing is installed in the housing hole, the elastic force of the bearing bearing itself can be used to closely fit the bearing housing hole to facilitate heat dissipation. Check whether the bearing has a dumb sound, you can knock on the back of the bearing to listen, there is a mute sound indicating that the alloy and the bottom plate are not firmly combined, and should be re-selected.

The mating clearance of the bearing journal should be appropriate.

When selecting bearings, the mating clearance must be checked. During the inspection, the pads and journals are measured with a cylinder gauge and a micrometer, the difference of which is the mating clearance. The inspection method of the mating clearance of the bearing is as follows:

For the connecting rod bearing, apply a thin layer of engine oil on the bearing, put the connecting rod on the corresponding journal, tighten the bolt according to the specified torque value, and then shake the connecting rod by hand, which can rotate 1 1 2 turns, and pull the connecting rod along the axis direction, without a feeling of clearance, that is, it meets the requirements; For the crankshaft bearing, apply engine oil on the surface of the crane bearing of each journal, install the crankshaft and tighten the bolt according to the specified torque value, and pull the crankshaft with both hands, so that the crankshaft can rotate 1 2 times, and the rotation is light, uniform and no blockage.

Crankshaft bearings are generally divided into two types: bearings and flanging bearings. Playing the role of bearing and lubrication, the flanging bearing can not only support and lubricate the crankshaft, but also play the role of axial positioning of the crankshaft.

Crankshaft pads refer to the pads that are installed on the fixed brackets of the crankshaft and cylinder block and play the role of bearing and lubrication.

It is quite a bearing when combined with oil, turning the linear motion of the piston into the circular motion of the crankshaft.

A bearing is a type of bearing.

Bearings are divided into sliding bearings and rolling bearings, sliding bearings are bearing pads, and rolling shaft bearings are the kind with balls.

There are two kinds of bearings, one is the bearing that is divided into two halves, which is called the bearing. The other is unified, called axle sleeve.

The bearings are made of babbitt, which is oil-impregnated and wear-resistant.

The speed is low, the load is large, and most of them use sliding bearings, that is, bearings;

The speed is high, the load is small, and most of them use rolling bearings.

For example, the axles of trains are matched with bearings.

As long as there is a rotating place, there will be a bearing, and there will be lubrication of the bearing.

The most important bearing on the engine is on the crankshaft. On the crankshaft, there is a crankshaft journal that supports the operation of the crankshaft, and a connecting rod shaft diameter that connects the connecting rods. These journals are equipped with bearings.

The running shaft and the fixed tile rub against each other, and sufficient lubricating oil must be supplied. The shaft is separated from the pad, and only the oil film between the two is rubbed.

Between the connecting rod and the piston pin, on the valve camshaft, on the rocker shaft. There are bearings.