| Gear pump is gear in the world, as an important industrial application of hydraulic components. It has a simple structure, small size, light weight; pollution sensitivity is small, easy maintenance, low price and so on, which determine its hydraulic system to occupy a pivotal importance. However, due to the existence of ordinary gear pump radial force balance, flow ripple, noise and other defects, it can’t change displacement has been greatly limited the scope of use. The subject comprehensives general structural characteristics of the gear pump design external multi-gear variable gear pump, reducing the shortcomings of the hazards.In this paper, through the common external gear pump and variable gear pump working principle and flow characteristics of the analysis and comparison, and the smallest gear pumps and flow pulsation minimum for two-goal, we establish a variable gear pump mathematical model optimized the structure, and then use optimization software to analyze the optimal solution obtained.Then for the existence of radial gear pump fluid pressure, the phenomenon of trapped oil analysis and calculation, we can see the variable pump driving wheel completely balance the radial hydraulic pressure. When the same displacement, the tip diameter of the pump reduces about one-third than the average, the driven wheel radial force also lessens about one-third, and pump size decreases, the force improves, which not only to extend the working life of the gear, but to solve the gear pump of high pressure to provide effective measures. While designing the main parts, the variable structure and material selection, it shows that the minimum engagement variable axial width not less than one-third of tooth width, the maximum displacement is about three times than the minimum displacementAfter that we utilize the finite element analysis software for multi-gear variable pump for static analysis, and to draw the stress under a given load, displacement and factor of safety contours, etc., to observe and analyze the results, forecast to assess whether to meet the job requirements, which improving the reliability of the structural.Followed by analysis of the common external pump and multi-gear variable pump geometry flow, instantaneous flow and flow characteristics, obtained by theoretical analysis of instantaneous flow more than larger, flow pulsation decreased significantly, greatly improve traffic quality. After simulation, verify the authenticity of the conclusions.To further explore the multi-gear variable pump, by using of virtual prototyping simulation technology for kinematic simulation and gear meshing force dynamics simulation. The initial establishment of the structure using three-dimensional software model, earned the angular velocity simulation results with the contact force diagrams, and observations. While the ordinary external pump for virtual motion simulation, through comparative analysis, we found that the pulse of angular velocity is lower, contact force fluctuations is smaller and peak drops, flow pulsation is reducing, it significantly reduced the impact and vibration damage to the hydraulic system to verify the feasibility of this structure, but also to shorten the product design cycle, improve the work efficiency.Finally, to capture the internal gear pump changes the flow field leakage, we apply finite element analysis software to simplify three-dimensional model of this pump for flow field simulation. Focusing on major leaks including end clearance and radial clearance, and came to2MPa pressure, different end clearance, radial clearance and the relationship between the leakage flow, for in-depth study of the internal gear pump flow has laid a solid foundation.Figure [80] table [13] reference [76]... |
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