The reliability of auto water pump
2009
Automotive water pump has already begun to study the current domestic, automotive water pump reliability and life is first.
1, due to high speed automobile engine, and the operating conditions change greatly, high coolant temperature (90 degrees, limit 110 degrees), increased the difficulty of the design of automotive cooling pump.
2, auto cooling pumps, domestic pumps manufacturers pay little attention to the efficiency, in order to reduce costs, the general efficiency of the pump are about 30%. I know the Japanese Honda, Mazda car cooling pumps are 42-46% efficient. For the open impeller efficiency is already very high, manufacturing processes are also very good.
3, auto cooling water pump should be said that one of the special application of centrifugal pumps. Its design philosophy and principles and pump the same, but taking into account the cylinder block structure, process, and the special requirements of automotive engines, we can see that the design of automotive water pump centrifugal pump design methods and general method is not the same impeller width wide , vortex shell design is not in full accordance with the ordinary volute design. The current structure of foreign enterprises with the impeller is more pressing than the impeller, low cost, high efficiency; leaf structure varied, there arc blades, a straight blade, but also post-curved blades and so on.
4, for the reliability of automotive water pump first thing to consider is the axial force balance and cavitation. When these two points in the design must be rigorous calculations, we usually use CFD calculations and projections.
5, because imports are generally 0.98MP the system pressure, cavitation performance improvement, the easiest way is to increase the import of the impeller, of course, leaves the layout and import placed Angle on Cavitation Performance of a larger impact.
6, shaft seal, bearing in order to better reliability, generally adopts the imported. The reliability of these vulnerable components even more important.
7, for general requirements for automotive water pump pressure difference 140kp, according to our experience, manufacturers have designed 200kp above, this point is not taking into account the requirements of the system characteristic curve of pipeline? Or the design of a conservative? If you can down 14KPa, this can reduce the shaft power, improve engine efficiency.
8, to study and design of automotive water pumps, need to test out the cars cooling system characteristic curve, in order to design sound science.