| Home>Bearing knowledge>Analysis and discrimination of crankshaft ablation |
Analysis and Discrimination of Crankshaft Ablation
Source: Bearing network time: 2018-02-08
| /*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089'; |
1. Poor oil quality
1) The quality of the oil is low. The selected oil quality grade and viscosity grade are lower; or the same trademark oil is used for blending; the performance of the oil is not up to the demand, and a lot of dust is mixed in the oil application process; The working temperature is too high to make the oil oxidize and change. The oil of oxidized bismuth is black and dull; the concentration is increased; the oil is rubbed with two fingers; the oil is found to have dust, impurities, etc. If the oil used is found to have the above appearance; replace.
2) The oil is thinned. Because some diesel engine fuel injection pumps are smooth and smooth, the pressure is smooth; once the fuel injection pump and the smooth oil passage seal are ineffective, the diesel oil enters the smooth oil chamber; the diesel engine will be diluted with the smooth oil. In addition, if the water jacket has cracks or Bottom hole; making cooling water into the oil will also make the oil thin.
You can check whether the upper part of the diesel engine (plane on the cylinder head, valve structure, cylinder head cover) can have water vapor or water droplets. If it is found that the oil capacity is added in the application, the concentration is decreased; the viscosity is decreased; and the oil smell is clarified. Diesel oil is mixed in the oil.
2. The oil inventory is not good, the oil pressure is low, the oil inventory is not good, and the oil pressure is low; it will constitute a lack of smooth oil flow of the diesel engine; thus, it cannot ensure a smooth oil film between the crankshaft journal and the bearing bush of the diesel engine.
You can check the amount of oil in the oil sump and the reading of the oil pressure gauge; further check the oil pipeline for abnormalities such as clogging and leakage.
3. The crankshaft journal and the bearing bush are too large or too small
1) The crankshaft journal and the bearing bush are too large; the diesel engine oil pressure is low; it can not be formed to meet the smooth oil film.
2) The crankshaft journal and the bearing bush are too close.
When the gap is too large or too small; the cylinder, bearing hole, bearing bush scale can be viewed with a micrometer and a cylinder table; the cooperation gap can be calculated; and the cooperative gap can also be directly measured by the feeler gauge.
4, the crankshaft or the cylinder's several scales are out of tolerance
1) The crankshaft radial runout is large; the gap between the journal and the bearing bush is small or no gap; the thickness of the smooth oil film is not good or there is no smooth oil film.
2) The coaxiality of the main bearing bore of the cylinder is too poor; the gap between the main journal and the bearing shell is too small or void; the thickness of the smooth oil film is not good or there is no smooth oil film.
3) The straightness of the cylinder and the main bearing hole is too poor; the gap between the journal pin and the main journal is too small or void; the thickness of the smooth oil film is not good or there is no smooth oil film.
In the case that the diesel engine is not used for a long time after the new machine or overhaul; it will often constitute the above-mentioned appearance. It is concluded that several scales of the excess position can be shaken by hand to crank the diesel engine crankshaft (rotational force); then the diesel engine mains are unloaded by cylinder. Bearing cap and connecting rod bearing cap; re-transform the crankshaft. According to its rotating crankshaft torque, æµ é’œ æµ é’œ 淳咛 淳咛 范 ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( (
5. The shape of the crankshaft main journal and the connecting rod journal is out of tolerance. The crankshaft main journal, the connecting rod journal or the main bearing bore of the cylinder, and the large spheroidal or taper difference of the connecting rod are large; the gap between the journal and the bearing bush will be broken. Continued (continuous) or tapered. It does not ensure a good smooth oil film.
After the new machine or overhaul, the diesel engine is not put into operation for a long time; it is easy to attack the above-mentioned appearance; the journal scale can be measured. If the journal is ablated, the adjacent journal can be measured (the adjacent corresponding journal is used according to the convention) Use the same equipment, the same cutting tool processing; then it can represent the shape error of the ablation journal).
6. The roughness of the crankshaft main journal and the connecting rod journal is poor due to the roughness; there are many metal peaks on the outer surface of the journal; it destroys the integrity and continuity of the smooth oil film between the journal and the bearing. Metal The ridges directly collide with the bearing pads; they constitute crankshaft ablation.
Frequent attacks occur after the new machine or overhaul. The diesel engine is not put into operation for a long time. If the measured journal is ablated, the roughness detector can be used to measure the adjacent corresponding journal (since the case is; the adjacent equipment is selected by the same equipment, The same cutting tool is processed; then the measured roughness can represent its ablation journal roughness).
7. When the crankshaft, flywheel and clutch dynamic balance exceeds the differential balance, the inertia force of the crankshaft is rotated at high speed; the cooperation gap between the crankshaft journal and the bearing bush is damaged; if the crankshaft and the bearing bush directly collide, the crankshaft burns. eclipse.
The problem usually occurs when the machine travels for 10,000km. After the crankshaft is ablated, the residual debris on the journal can be removed; the balance is checked from the head; the unbalance can basically indicate the ablation of the axicon.
8. Protection against improper protection If the diesel engine is not operated for a reasonable period of time, if it is not properly protected and protected in time, the components such as the oil pump pressure limiting valve will be worn out and deformed. The oil filter element will be blocked by oil and sludge; Pressure drop; causing crankshaft ablation.
Recommend to friends comments close window
| Bearing related knowledge |
| The development of China's bearing industry and the need for bearing equipment for numerical control equipment (1) Characteristics of polymer oil-impregnated bearings |
This article links to http://
Please indicate China Bearing Network http://
Previous:Installation and protection of rolling mill bearings (1)
The next part: Introduction to the "in-the-shelf packaging of rolling bearings"
The principle of capacitive type sensor is to use positive and negative probes filled with liquid medium to form a linear change with the liquid level, the change of capacitance (that is, the change of liquid level) into a standard electrical signal output. The core components of the product use highly integrated special capacitance measurement chip, through accurate temperature compensation and linear correction, with high precision, high stability and continuous measurement advantages, with a strong independence. We provide customers several capacitive oil level sensors to meet your needs. You can choose one product according your medium, range, output signal and etc. We also provide OEM services, you can get your suitable products if you have special requirements of the products.
Capacitive Fuel Level Sensor,Capacitive Oil Level Sensor,Capacitive Fuel Sensor,Capacitive Type Sensor
Xi'an Gavin Electronic Technology Co., Ltd , https://www.cngamicos.com