Mike@kuake.biz
Piston function of diesel generator set
Article source:this site | Issuing time：2019-04-15
The function of the piston of a diesel generator set is to withstand the pressure of gas and transmit the force to the crankshaft through the connecting rod.
The working condition of the piston is very bad, it is under the action of high temperature and high pressure gas, it continuously makes high-speed reciprocating linear motion. Due to the periodically changing gas pressure and reciprocating inertial force, the piston bears a great mechanical load and thermal load, and the uneven temperature distribution will cause thermal stress. Therefore, the piston must have a lighter weight and sufficient strength and rigidity. The piston works under the conditions of high temperature, high pressure and high speed, and its lubrication conditions are poor, and the piston and the cylinder wall have serious friction. To reduce wear, the surface of the piston must be wear resistant.
The pistons of high-speed diesel engines are usually made of cast aluminum alloy. With the continuous strengthening of diesel engines, the number of pistons using wrought aluminum alloy or eutectic aluminum-silicon alloy is increasing, and high-pressure diesel engines mostly use cast iron pistons. The purpose is to increase the strength of diesel engines and reduce the coefficient of thermal expansion.
Top: The top is a part of the combustion chamber, and its structural shape is related to the form of the engine and combustion chamber. Small diesel engines mostly use flat-top pistons, which have the advantages of simple manufacturing and small heating area. In some diesel engines, in order to prevent the valve from colliding with the piston crown, a shallow valve avoidance dent is made on the top.
The large thermal load on the piston of a diesel engine often causes the piston to cause thermal fatigue and cracks. Therefore, some diesel engines can inject oil from the fuel injection hole on the small end of the connecting rod to cool the inner wall of the piston crown; some diesel engines have a special fuel injection mechanism in the body, which can play the same role.
Ring groove part: also known as leak-proof part or head. It is mainly to install the piston ring to prevent fuel or gas from leaking into the crankcase, and transfer the heat absorbed by the piston to the cylinder wall through the piston ring, and at this time prevent the lubricating oil from entering the combustion chamber. The piston head is machined with several ring grooves for installing piston rings. The bottom of the oil ring groove is drilled with many radial small holes, so that the oil ring scrapes the excess lubricating oil from the cylinder wall and flows back to the crankcase from the small holes.
Some diesel engines have small heat-insulating grooves between the piston crown and the first ring groove, or up to the following ring grooves. With the continuous strengthening of diesel engines, in order to improve the groove resistance of the first and second ring grooves, some diesel engines insert heat-resistant and wear-resistant austenitic cast iron guard rings on the ring grooves.
Piston pin seat: The pin seat is used to install the piston pin and mainly plays the role of transmitting air pressure. There are often ribs between the piston pin seat and the top to increase rigidity. The pin seat hole is provided with a ring groove for installing an elastic snap ring. The piston pin snap ring is used to prevent the piston pin from axially moving during operation, leaning out of the piston pin seat hole and damaging the cylinder block.
Skirt: The part below the lowest oil ring groove of the piston head is called the skirt. Its function is mainly guided by the movement of the piston in the cylinder, and it also bears side pressure. Due to the high gas pressure and high side pressure of diesel engines, the skirt is also relatively long to reduce pressure and wear per unit area.
Because the cylinder pressure of the diesel engine is very large, the skirt is required to have a large enough pressure bearing area, and it must be kept in the best fit with the cylinder wall under any circumstances. Therefore, the piston skirt is usually not cut, but the piston is axially made into a conical shape with a small upper and a large lower, and the skirt is made into an oval radially. Therefore, the assembly clearance between the piston and the cylinder wall of a diesel engine is larger than that of a gasoline engine. In order to ensure that the diesel engine has sufficient pressure and temperature at the end of compression, better sealing is required. Therefore, the diesel engine should have more sealing rings and oil scraper rings.
The working condition of the piston is very bad, it is under the action of high temperature and high pressure gas, it continuously makes high-speed reciprocating linear motion. Due to the periodically changing gas pressure and reciprocating inertial force, the piston bears a great mechanical load and thermal load, and the uneven temperature distribution will cause thermal stress. Therefore, the piston must have a lighter weight and sufficient strength and rigidity. The piston works under the conditions of high temperature, high pressure and high speed, and its lubrication conditions are poor, and the piston and the cylinder wall have serious friction. To reduce wear, the surface of the piston must be wear resistant.
The pistons of high-speed diesel engines are usually made of cast aluminum alloy. With the continuous strengthening of diesel engines, the number of pistons using wrought aluminum alloy or eutectic aluminum-silicon alloy is increasing, and high-pressure diesel engines mostly use cast iron pistons. The purpose is to increase the strength of diesel engines and reduce the coefficient of thermal expansion.
Top: The top is a part of the combustion chamber, and its structural shape is related to the form of the engine and combustion chamber. Small diesel engines mostly use flat-top pistons, which have the advantages of simple manufacturing and small heating area. In some diesel engines, in order to prevent the valve from colliding with the piston crown, a shallow valve avoidance dent is made on the top.
The large thermal load on the piston of a diesel engine often causes the piston to cause thermal fatigue and cracks. Therefore, some diesel engines can inject oil from the fuel injection hole on the small end of the connecting rod to cool the inner wall of the piston crown; some diesel engines have a special fuel injection mechanism in the body, which can play the same role.
Ring groove part: also known as leak-proof part or head. It is mainly to install the piston ring to prevent fuel or gas from leaking into the crankcase, and transfer the heat absorbed by the piston to the cylinder wall through the piston ring, and at this time prevent the lubricating oil from entering the combustion chamber. The piston head is machined with several ring grooves for installing piston rings. The bottom of the oil ring groove is drilled with many radial small holes, so that the oil ring scrapes the excess lubricating oil from the cylinder wall and flows back to the crankcase from the small holes.
Some diesel engines have small heat-insulating grooves between the piston crown and the first ring groove, or up to the following ring grooves. With the continuous strengthening of diesel engines, in order to improve the groove resistance of the first and second ring grooves, some diesel engines insert heat-resistant and wear-resistant austenitic cast iron guard rings on the ring grooves.
Piston pin seat: The pin seat is used to install the piston pin and mainly plays the role of transmitting air pressure. There are often ribs between the piston pin seat and the top to increase rigidity. The pin seat hole is provided with a ring groove for installing an elastic snap ring. The piston pin snap ring is used to prevent the piston pin from axially moving during operation, leaning out of the piston pin seat hole and damaging the cylinder block.
Skirt: The part below the lowest oil ring groove of the piston head is called the skirt. Its function is mainly guided by the movement of the piston in the cylinder, and it also bears side pressure. Due to the high gas pressure and high side pressure of diesel engines, the skirt is also relatively long to reduce pressure and wear per unit area.
Because the cylinder pressure of the diesel engine is very large, the skirt is required to have a large enough pressure bearing area, and it must be kept in the best fit with the cylinder wall under any circumstances. Therefore, the piston skirt is usually not cut, but the piston is axially made into a conical shape with a small upper and a large lower, and the skirt is made into an oval radially. Therefore, the assembly clearance between the piston and the cylinder wall of a diesel engine is larger than that of a gasoline engine. In order to ensure that the diesel engine has sufficient pressure and temperature at the end of compression, better sealing is required. Therefore, the diesel engine should have more sealing rings and oil scraper rings.
In the electrical age, no matter what dangerous place, as long as there is human civilization, electricity is inseparable. Fujian Quark Motor is powered by the brand and cooperated with the self-developed silent protection assembly process, so that the power generation unit can always guarantee power supply whether it is in the alpine or subtropical zone.
Quark Motor specializes in producing diesel generator sets，Volvo diesel generator set，Yuchai diesel generator set，Cummins diesel generator set，Shangchai diesel generator set，400kw Cummins diesel generator setWait for a full range of diesel generator sets, consultDiesel generator set manufacturers,to understandingdiesel generator set offer, welcome to inquire; we are a manufacturer of diesel generator sets, and we will solve your power problems in all aspects!24-hour hotline：400-966-0200,website：en.kuake.biz
闽公网安备 35098102351072号
