Reasons for unstable speed of diesel generator and generator traveling
The speed of the diesel generator set is unstable during operation, and the reasons for the decrease in speed and traveling are as follows. The following reasons are briefly analyzed by Jiangsu Lide Power Equipment Co., Ltd.
柴油发电机 在怠速运转时忽快忽慢，但规律性不强，并有抖动，且柴油发电机在急减速、换挡或带负荷时易熄火，此现象多属调速器有故障而引起的。 It means that the diesel generator is running slowly and idly at idle speed, but the regularity is not strong and there is jitter, and the diesel generator is liable to flame out during rapid deceleration, gear shifting or load. This phenomenon is mostly due to the failure of the governor Caused. There are several reasons for this.
1 ）飞球磨损 ( 1 ) Flying ball wear
At idle speed, the opening degree of the flying ball is the smallest, and the spring sliding sleeve excessively stretches toward the flying ball due to the wear of the small rollers of the flying ball, causing random direct collisions with the flying ball body, resulting in unstable idle speed. At this time, if you touch the refueling joystick with your hand, you will feel a slight impact.
2 ）怠速弹簧弹性变差或调整不当 ( 2 ) Poor elasticity or improper adjustment of the idle spring
When the diesel generator is running, the increase in load will reduce the speed. If the idling spring or starting spring becomes soft, the fuel supply tooth bar cannot move quickly to the fuel increase direction to increase the rotation speed, and in severe cases, the diesel generator will automatically stop.
3 ）稳速弹簧调整不当 ( 3 ) Improper adjustment of steady speed spring
During idling operation, because the flying ball has a small centrifugal force, the speed control force is also small. If the diesel generator suddenly decelerates, the adjustment movement of the fuel supply rod may exceed the idle position, causing the diesel generator to stall. In order to prevent this situation, behind the governor cover is a stabilizing spring that pushes the oil supply gear rod toward the idle position. If the spring is too soft or adjusted to the side, it will weaken or fail to stabilize the speed and make the idle operation unstable. .
4 ）低压油路供油不畅或含有水和空气 ( 4 ) Poor oil supply in low-pressure oil circuit or containing water and air
This will make the fuel supply amount large and small, especially in low speed areas, which will cause the diesel generator to work unstable.
5 ）喷油泵支承凸轮的凸轮轴锥轴承磨损过大 ( 5 ) The camshaft tapered bearing of the injection pump supporting cam is too worn
, 使柴油发电机转速不稳 . In this case, the camshaft will cause irregular movement in the axial direction , which will make the diesel generator's speed unstable .
6 ）喷油泵供汩不匀，供油不正时或喷油不良 ( 6 ) Uneven supply of fuel injection pump, improper fuel supply or poor fuel injection
In the case of low-speed operation, if the oil supply is uneven or the fuel supply is not correct, it will have a greater impact on the stability of the speed, but this instability is well-regulated.
Law, and the period is short.
7 ）气缸压缩力不足 ( 7 ) Insufficient compression force of the cylinder
When the cylinder compression force decreases, the degree of decline of each cylinder may not be the same. Even if the fuel supply of the injection pump is balanced, the combustion situation may still be different, resulting in unstable speed at low speeds.
“游车”，是指柴油发电机在低速和中速的范围内出现周期较长且较有规律的时快时慢现象，这是调速反应过分滞后于实际转速变化的结果。 The so-called "touring car" refers to the phenomenon that the diesel generator has a longer and more regular time in the range of low and medium speeds. This is the result of the speed regulation response lagging too much behind the actual speed change. There are several reasons for this.
1 ）调速器内部杠杆因连接销孔磨损而松旷 ( 1 ) The internal lever of the governor is loose due to the wear of the connecting pin hole
In this case, the two-way speed-regulating movement that increases or decreases the fuel supply amount causes excessive change in direction lag. When the engine is running, the speed response must lag behind the actual speed change.
But the hysteresis cannot be too large, otherwise it will produce a large adjustment amplitude. “游车”现象。 The adjustment amplitude is too large, that is, when the speed has been increased or decreased due to the increase or decrease of the fuel supply, the fuel will continue to increase or decrease until the speed exceeds the governor's adjustment range, and its strong feedback signal passes the governor The reaction of reverse regulation was achieved, and as a result, the speed regulation response exceeded the predetermined range, which caused the phenomenon of "travel" where the rotation speed was repeatedly raised and lowered near a certain value .
2 ）供油齿杆不够灵活 ( 2 ) The fuel supply rack is not flexible enough
The fuel supply rod of the fuel injection pump must be kept absolutely flexible to ensure the sensitivity of the speed response. Pull the drag resistance test of the rack with a sensitive spring scale, corresponding
IV 、 VI 、 VIII 缸喷油泵的拉动阻力应分别不大于 60 、 90 、 130 、 150g 。 The pull resistance of the fuel injection pumps of cylinders II, IV , VI and VIII should not be greater than 60 , 90 , 130 , 150g, respectively . Due to rust, deformation of the plunger and coupling after tightening, damage to the engagement between the ring gear and the toothed rod after the plunger spring is broken, severe wear of the end sleeve of the toothed rod, and the angle of the fork of the fork-type oil quantity adjustment mechanism Incorrect, the installation of the thrust swashplate of the domestic fuel injection pump governor and the poor installation or poor cooperation of the ball seat will affect the flexibility of the fuel supply rack. “游车”现象（若供油齿杆完全不能移动，出现故障现象将视齿杆停留位置不同而有所区别；例如，柴油发电机不能启动、不能熄火、转速不受控制、飞车等） When the resistance that affects the flexibility has not reached the level where the fuel supply rack cannot be moved at all, a “car traveling” phenomenon will occur (if the fuel supply rack is completely unable to move, a failure phenomenon will depend on the rack stay position Different; for example, diesel generators cannot start, cannot stall, uncontrolled speed, speeding, etc.)
3 ）稳速弹簧调整不当 ( 3 ) Improper adjustment of steady speed spring
“游车”，是因为稳速弹簧与供油齿杆不能共同灵活的起作用。 This is similar to the improper adjustment of the steady speed spring when the idling speed is unstable. The reason why this situation appears as "parking" is because the steady speed spring and the fuel supply rack cannot work together flexibly.
The above are some of the problems and solutions in the process of using diesel generators by Reed Power Equipment Co., Ltd. for many years. The company is a diesel generator manufacturer. It mainly provides Cummins generators, Diesel generator sets and Volvo generator sets have also received direct authorization from many diesel engine manufacturers.
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