| Internal cycloid gear pump has the merits of small size, light weight, strongsuction, low noise, small flow pulsation etc, and it is widely used in small and mediumpower engine. However, due to the tooth profile’s complex shape, modeling and processingare often difficult. In addition, flow pulsation and volume efficiency are the two importantto evaluate the oil pump, oil pump design parameters and oil pump internal fluid flowcharacteristics are closely related to how superior they are. A high quality oil pump shouldhave the characteristics of high volume efficiency and low flow pulsation. According to theabove question, this paper makes intensive study by using the method of combiningtheoretical analysis with experimental simulation, and provides a new method for oil pumpdesign.Firstly, the forming principle of cycloid pump rotor tooth profile curve isanalyzed, and the basic structure parameters of rotor are determined. Based on3dmodeling software UG, rotor pump’s rotor parameterized modeling module is developed,and the process of how to further develop the UG by using the vb.net language isintroduced in detail.The main factors influencing volume efficiency is leaking. Based on the theoryof fluid mechanics aperture leak, this paper establishes the mathematical model of rotorpump end leakage and radial leakage, and theoretically analyzes the phenomenon of rotorpump clearance leaking. Besides, according to the rotor pump instantaneous flow, thegenerating mechanism and influencing factors of rotor pump flow pulsation are analyzed.According to the theoretical analysis, the oil pump software was designed. Throughinputting the basic parameters such as displacement etc., all relevant design parameters ofinternal and external rotor can conveniently obtained, so as to realize the visualization ofrotor profile in the interface. Combining with the development UG module, oil pump parametric design can be fully realized.With the target of Minimum displacement of oil pump unit volume, the oil pumpdeveloped in this paper is optimal designed. According to the optimization results, themodel is builded by using the developed UG module, then the oil pump internal fluid3dmodel is derived. rotor pump fluid characteristics is analyzed by using Pumplinx which ispump software, and based on the result analyses, the change of rotor pump internalpressure fluctuations, the reason of clearance leakage and the influence factors are obtained.Analyzing the oil pump cavitation phenomenon forming conditions with high speed, andthe problem of volume efficiency changing with engine speed is well explained.Finally, building the oil pump comprehensive performance test-bed and finishingthe pump comprehensive performance test. Based on the test result, oil pump flowcharacteristic and volume efficiency changes are analyzed. The accuracy of the simulationresults is verified by comparing the numerical calculation results and the simulation results.Meanwhile, durability test is taken in the durability test-bed, and the experimental resultsshow that the design prototype completely reaches the standard service life, whichvalidates the feasibility of design procedure and develop method. |
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