What should I do if the crankshaft is too tight when the engine is assembled?

with ink. The oil is applied to the crankshaft, close it first, see the height of the tile, scrape it and try it until it can basically turn easily.

Car engines.

Crankshaft piston how to fit the tile.

Engine crankshaft and connecting rod pads, first use an outer diameter micrometer.

Detect the diameter and degree of roundness of the crankshaft wear and whether it is out of limit. If the size of the crankshaft is a rotary shaft.

The neck is within the specified range, and then determine whether the degree of wear requires grinding shafts. Depending on the size of the shaft, determine what pads to use.

Such as standard bearings, which level of bearings to increase.

Determining the bearing is part of the assembly process. The assembly process is as follows:

1. Apply oil to the crankshaft journal.

2. Install the optional bearing pad at the required position and position.

3. Add a clearance adjustment pad before installing on the crankshaft.

4. The corresponding crankshaft is installed, and the bolts are slightly tightened.

5. Rotate the crankshaft left and right. (If you can't turn the crankshaft, the bolt is too tight, loosen the bolt some.) 6. Remove the bearing and check the bearing to eat the matching surface.

7. After many times of scraping the tile, the crankshaft and the bearing have eaten the joint surface to the bottom of the tile, and the eating surface has reached more than 80%.

8. Tighten according to the standard bolt torque, and rotate the crankshaft to detect the tightness.

9. If it is a set of tiles for replacement, the tightness is required to be consistent.

10. After the detection is correct, the tile is completed.

1. The crankshaft is difficult to rotate or cannot rotate after assembly.

1) During assembly, the relevant mating surfaces are not coated with oil or grease is mistakenly applied, so that the movement resistance increases.

2) The bearing and journal fit too tightly. Generally, it is due to the fact that the new tile is not scraped with the tile cover and the upper and lower tiles are reversed, the tile installation height is too large, the pad is mistakenly added to the back of the tile, and the connecting rod bolt or the bolt of the main bearing cover is too tight, etc., so that the tile is deformed and partially locked with the crankshaft journal.

3) Due to the installation of thrust plates and other reasons, the crankshaft has no axial intersection, and the crank and the outer edge of the spindle bearing collide.

4) The relevant shafts (such as camshafts, speed regulating shafts, starting shafts, etc.) are too tightly matched with the bushing: the crankshaft and the oil seal are too tightly fitted, etc.

5) The single-cylinder diesel engine is less or missing to install the gasket between the oil pump and the body, when the pump body bolt is tightened, the oil pump rotor shaft is dead under the balance shaft 6) The gasket of the gear chamber cover of the single-cylinder diesel engine is too thin, and the starting shaft shoulder and the gear chamber cover are seriously rubbed; Or the end face shoulder of the starting shaft bushing is too thick, and the end face shoulder of the starting gear collides with the end face of the starting gear after installation.

7) The casing of the flywheel generator of the single-cylinder diesel engine collides with the casing on the flywheel, which increases the rotational resistance.

8) During assembly, the piston ring is broken or the piston pin circlip comes out, and it is stuck between the cylinder liner and the piston; Or the end clearance of the enlarged piston ring is too small, and the carbon deposits in the ring groove are not removed when the new ring is replaced.

9) There is a foreign object jam port between the flywheel and the flywheel housing of the multi-cylinder engine.

10) The parts are unqualified, such as the main journal of the crankshaft or the main bearing seat hole of the body is different shafts: the connecting rod big head touches the crank: the connecting rod small head touches the piston pin, etc.

Bearings can be inspected and scraped using the coloring method. When inspecting by coloring method, the bearings should be cleaned first, and the bearings should be free of defects such as shelling, cracks, hard spots, and dense sand holes.

Because the new bearing needs to be scraped and matched, it can not be used immediately, the purpose of the bearing grinding and scraping is to form a circular geometric shape of the tile lining, so that there is a wedge-shaped gap between the bearing and the shaft strength, so as to ensure that when the shaft is rotated, a wedge-shaped oil film can be formed between the friction surfaces, so that the shaft diameter rises and leaves the tile lining, and operates under the buoyancy of the oil film, so as to reduce the friction with the tile lining and reduce its wear and power consumption.

When the engine starts, if the transmission is placed in the neutral position and the starting switch is pressed, the starter makes a sound and the crankshaft cannot rotate when the starting system is intact, it is a mechanical failure.

The reason why the crankshaft does not rotate.

The starter is poorly engaged with the flywheel teeth. Ring gears and starter gears can collide when the engine is started, causing tooth damage or wear on one side of the tooth. If the teeth are damaged or worn more than three times in a row, it will be difficult for the starter gear and ring gear teeth to mesh.

Sticky cylinder. When the engine temperature is too high, the engine is stopped and the engine is turned off, the heat is difficult to dissipate, and the piston ring at high temperature is adhered to the cylinder, and it cannot be started after cooling.

The crankshaft is locked. Due to the failure of the lubrication system or the lack of oil, the sliding bearing is dry, so that the crankshaft is finally locked and cannot be started.

The plunger of the fuel injection pump is stuck.

Diagnosis and repair method of crankshaft not rotating.

If the flywheel has more than three teeth in a row, and they are exactly opposite the starter teeth, the two gears will not be able to mesh. In this state, simply pry the flywheel at an angle with a spudger and press the start button to start smoothly. For damaged flywheel teeth, welding can generally be used to repair them.

When the ring gear is loose, it can be confirmed from the starter mounting port of the flywheel housing. If the ring gear is loose, it must be replaced with a new part. During installation, the ring gear should be heated in a heating box, and then pressed on the flywheel while it is hot, and then it can be fastened to the flywheel after cooling.

When the unilateral wear of the ring gear teeth is serious, the ring gear can be pressed down, and the front and rear end faces can be turned over, and then installed on the flywheel for use.

After checking that the gear mesh is normal and the flywheel does not rotate when starting, it should be regarded as an internal fault of the engine, such as crankshaft locking, piston sticking to the cylinder, clutch stagnation, etc., which should be further observed. You can first check whether the clutch is damaged and stuck, and then check whether the plunger of the fuel injection pump is stuck and whether there are foreign objects inside the engine.

If the crankshaft of the engine is not able to rotate, then there is a problem with the mechanical parts, it may be that the shaft and the tile are bursting to death, or the torque of the screws was too hard and too big last week. Then there is the state hail crankshaft, which is not concentric, etc., and the rest will be disassembled and checked.

Engine crankshaft.

Mounting with camshafts.

The location is not reasonable, it is recommended that you re-disassemble and put it back on:

1. The most important component in the engine. It withstands the grinding force of the connecting rod and converts it into torque output through the crankshaft and drives other accessories on the engine to work;

2. The crankshaft is subjected to the centrifugal force of the rotating mass.

The inertial force of a gas that varies periodically.

The joint action of the reciprocating inertial force makes the crank bearing subject to the action of bending torsional load. Therefore, the crankshaft is required to have sufficient strength and rigidity, and the surface of the journal needs to be wear-resistant, uniform and balanced;

3. In order to reduce the mass of the crankshaft and the centrifugal force generated during movement, the crankshaft journal is often made hollow. Oil holes are made on each journal surface to allow oil to be introduced or withdrawn to lubricate the journal surface. To reduce stress concentration.

The connection of the main journal, the crank pin and the crank arm is connected by a transition arc;

4. The function of the crankshaft counterweight (also known as counterweight) is to balance the rotational centrifugal force and its moment, and sometimes it can also balance the reciprocating inertia force and its moment. When these forces and moments are in equilibrium, the counterweight can also be used to reduce the load on the main bearing;

5. The number, size and placement position of the counterweight should be considered according to the number of cylinders of the engine, the arrangement of cylinders and the shape of the crankshaft. The counterweight is generally cast or forged with the crankshaft, and the counterweight of high-power diesel engines is manufactured separately from the crankshaft and then bolted together.

Hello, I will solve your doubts for you, I hope it can help you. The camshaft and crankshaft are installed relative to the position of the New Year's Eve is unreasonable because the timing mark is not good or the belt is loose, the timing mark is good or the belt is tightened.

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It is recommended to go to a special maintenance point for adjustment, or clean the solenoid valve of the engine, it should be that the solenoid valve is blocked, and it is good to clean it.

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Dear, these are no problems, you need to find professional after-sales personnel for maintenance.

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