When the Yuchai generator is working, why is the oil pressure gauge indicating that the oil pressure value is too high, and what is the solution?
The engine lubrication system is based on the principle of the pressure generated by the oil pump. The oil in the lubrication system can generate pressure mainly because the oil has resistance to the oil pressure section in the system. The pressure is related to the flow resistance of the oil in the system. When the flow resistance in the system is large, the oil pressure is high, and when the flow resistance of the oil in the system is small, the oil pressure is low.
In addition, the oil pressure display device is abnormal and the displayed oil pressure value is inaccurate (that is, the oil pressure is too high), making it mistakenly believe that the oil pressure of the lubrication system is too high.
Common reasons for the increase in the oil flow resistance of Yuchai generators are:
1. Yuchai generator oil viscosity is too large
The viscosity of Yuchai generator oil indicates the internal friction resistance when the oil flows. The oil viscosity is related to the engine temperature. When the engine temperature is low, the oil viscosity is high; otherwise, the oil viscosity is small. When the oil viscosity is large, the fluidity is poor, but the sealing performance is good, and the leakage is small. If the oil viscosity exceeds the specified value, the oil flow resistance in the lubrication system will increase, and the pressure will increase at the same time. It can be seen from this that when the engine temperature is low or the viscosity of the oil itself is high (due to the improper selection of the oil grade, that is, the oil grade is not suitable for the ambient temperature, such as the selection of oil with high viscosity in summer in winter), the oil pressure will be high.
2. The clearance of the pressure lubrication part of Yuchai generator is too small or the oil fine filter is blocked
It can be seen from the lubricating oil circuit that the flow resistance of the oil circulation circuit of the lubrication system is equal to the sum of the reciprocal of the oil flow resistance of the parallel branch circuit. The camshaft journals, connecting rod journals, crankshaft journals, rocker shafts, etc. of the pressure lubricated parts, if the matching clearance of these lubricating parts is too small, the filter element of the fine filter is dirty and the oil circuit is blocked, and the pressure limiting valve is adjusted. If the pressure is too high, the flow resistance of the lubricating oil circuit will increase and the pressure will increase.
3. Improper adjustment of pressure limiting valve of Yuchai generator
The pressure limiting valve is limited by the balance spring and ball valve (or cone valve) to limit the oil pressure, so that the oil pressure does not exceed the specified value of the technical documents. When the oil pressure exceeds the specified value, the valve will be pushed open to release the pressure in the system against the elastic force of the spring. When the oil pressure is lower than the elastic force of the spring, the valve will be closed under the action of the spring, thereby limiting the pressure within the specified range. From this point of view, the oil pressure of the lubrication system depends on the size of the spring force. If the adjusted spring force is too large, the oil pressure in the system will be too high.
Diagnosis and exclusion
1. If the engine is newly put into use or after warranty, the oil pressure is obviously too high, indicating that the clearance between the journal of the pressure lubrication part and the bearing (tile) is too small, or the adjustment pressure of the pressure limiting valve is too high, it should be carefully Check the clearance between the journal and the bearing at the pressure lubrication part. If the gap is too small, it should be adjusted or scraped to avoid burning out the matching pair due to too small gap.
2. If the oil pressure is too high in the Yuchai generator that has been used for a long time, it means that the oil filter is blocked and should be cleaned.
3. If the oil pressure is too high when the diesel engine is at low temperature, when the engine temperature rises, the oil pressure is normal, indicating that the reason for the high oil pressure is that the temperature of the diesel engine is too low.
The engine lubrication system is based on the principle of the pressure generated by the oil pump. The oil in the lubrication system can generate pressure mainly because the oil has resistance to the oil pressure section in the system. The pressure is related to the flow resistance of the oil in the system. When the flow resistance in the system is large, the oil pressure is high, and when the flow resistance of the oil in the system is small, the oil pressure is low.
In addition, the oil pressure display device is abnormal and the displayed oil pressure value is inaccurate (that is, the oil pressure is too high), making it mistakenly believe that the oil pressure of the lubrication system is too high.
Common reasons for the increase in the oil flow resistance of Yuchai generators are:
1. Yuchai generator oil viscosity is too large
The viscosity of Yuchai generator oil indicates the internal friction resistance when the oil flows. The oil viscosity is related to the engine temperature. When the engine temperature is low, the oil viscosity is high; otherwise, the oil viscosity is small. When the oil viscosity is large, the fluidity is poor, but the sealing performance is good, and the leakage is small. If the oil viscosity exceeds the specified value, the oil flow resistance in the lubrication system will increase, and the pressure will increase at the same time. It can be seen from this that when the engine temperature is low or the viscosity of the oil itself is high (due to the improper selection of the oil grade, that is, the oil grade is not suitable for the ambient temperature, such as the selection of oil with high viscosity in summer in winter), the oil pressure will be high.
2. The clearance of the pressure lubrication part of Yuchai generator is too small or the oil fine filter is blocked
It can be seen from the lubricating oil circuit that the flow resistance of the oil circulation circuit of the lubrication system is equal to the sum of the reciprocal of the oil flow resistance of the parallel branch circuit. The camshaft journals, connecting rod journals, crankshaft journals, rocker shafts, etc. of the pressure lubricated parts, if the matching clearance of these lubricating parts is too small, the filter element of the fine filter is dirty and the oil circuit is blocked, and the pressure limiting valve is adjusted. If the pressure is too high, the flow resistance of the lubricating oil circuit will increase and the pressure will increase.
3. Improper adjustment of pressure limiting valve of Yuchai generator
The pressure limiting valve is limited by the balance spring and ball valve (or cone valve) to limit the oil pressure, so that the oil pressure does not exceed the specified value of the technical documents. When the oil pressure exceeds the specified value, the valve will be pushed open to release the pressure in the system against the elastic force of the spring. When the oil pressure is lower than the elastic force of the spring, the valve will be closed under the action of the spring, thereby limiting the pressure within the specified range. From this point of view, the oil pressure of the lubrication system depends on the size of the spring force. If the adjusted spring force is too large, the oil pressure in the system will be too high.
Diagnosis and exclusion
1. If the engine is newly put into use or after warranty, the oil pressure is obviously too high, indicating that the clearance between the journal of the pressure lubrication part and the bearing (tile) is too small, or the adjustment pressure of the pressure limiting valve is too high, it should be carefully Check the clearance between the journal and the bearing at the pressure lubrication part. If the gap is too small, it should be adjusted or scraped to avoid burning out the matching pair due to too small gap.
2. If the oil pressure is too high in the Yuchai generator that has been used for a long time, it means that the oil filter is blocked and should be cleaned.
3. If the oil pressure is too high when the diesel engine is at low temperature, when the engine temperature rises, the oil pressure is normal, indicating that the reason for the high oil pressure is that the temperature of the diesel engine is too low.
4. If the oil pressure is significantly too high after changing the oil, it means that the oil grade is not properly selected. For example, the oil with higher viscosity is selected in winter, that is, the oil pressure will be too high, and the oil that is suitable for the season should be replaced. The higher the oil grade (the larger the number), the lower the viscosity, and vice versa.
