渐开线外啮合齿轮泵的分析与设计

发布时间：2018-04-22 07:23

本文选题：齿轮泵 + 有限体积法　；参考：《西华大学》2012年硕士论文

【摘要】：齿轮泵在液压系统中的地位很重要，是保证液压系统正常工作的动力源。相对于其它结构的泵，齿轮泵结构简单、重量轻、价格低、制造简单、维护方便、转速变化范围大，并且系统对油液的污染不敏感，所以在机械系统中应用非常广泛。现代机械工程对齿轮泵也提出很多新要求，如压强高、排量大、脉动低、噪音低等，所以对齿轮泵的性能分析与改进成为了很重要的课题。本文对齿轮泵的流量特征、径向啮合力进行理论分析和数值计算，为齿轮泵的设计提供必要的理论依据。 1．根据渐开线形成原理得到齿廓方程、啮合线方程。并对齿轮啮合重合度、啮合滑动进行了分析。 2．分别计算了齿轮泵齿间区的流量、齿轮啮合区域的流量，最后就得到了齿轮泵的流量。在时间和转速确定的情况下，得到齿轮泵的流速。外啮合齿轮泵的结构对其内部的流场有很大的影响，采用fluent有限体积法求解计算模型，就不同中心距和转速情况下外啮合齿轮泵内部流场的变化特点进行对比。结果表明：（1）在齿轮泵的吸油口压强比压油口压强低，且流体压力呈周期性变化，在齿轮的啮合齿对间形成了困油；（2）中心距越小（大），出口处的平均速度越大（小），进出口压力差越大（小），困油区压力越高（低）；（3）出口流速和转速呈线性正比关系。设计时选用稍大的中心距可降低困油区压力。 3．通过理论分析可以知道齿轮周围的压力是周向变化的，齿轮受到的液压径向力是不对称的，并通过数值模拟得到了验证。由于两齿轮的啮合，齿轮间具有相互作用的啮合力，通过计算得到齿轮受到的啮合力和扭矩。通过有限元法，利用ansys软件，对齿轮啮合接触应力进行数值分析，得到了齿轮的应力分布情况，，为齿轮的设计提供参考。 4．围绕齿轮泵设计的参数进行讨论，只要确定了齿数Z、模数m、齿厚b，就能基本确定齿轮泵的结构，并讨论了齿轮泵设计中最关键的步骤。分析了困油的主要形成原因，并给出了困油的解决方法，即设计卸油槽。根据齿轮泵径向力的计算方法给出相关的减少径向力的方法。以流量脉动为优化对象，建立了设计参数优化模型。
[Abstract]:Gear pump plays an important role in hydraulic system and is the power source to ensure the normal operation of hydraulic system. Compared with other pumps, gear pump has simple structure, light weight, low price, simple manufacture, convenient maintenance, wide range of rotational speed change, and the system is insensitive to oil pollution, so it is widely used in mechanical system. Modern mechanical engineering also put forward a lot of new requirements for gear pump, such as high pressure, large displacement, low pulsation, low noise and so on, so the performance analysis and improvement of gear pump has become a very important subject. In this paper, the flow characteristics and radial meshing force of gear pump are theoretically analyzed and numerically calculated, which provides the necessary theoretical basis for the design of gear pump. 1. According to the involute formation principle, the tooth profile equation and meshing line equation are obtained. The degree of meshing overlap and the meshing slip of gears are analyzed. 2. The flow rate between teeth and gear meshing area is calculated, and the flow rate of gear pump is obtained. The velocity of gear pump is obtained when the time and speed are determined. The structure of external gear pump has great influence on its internal flow field. The fluent finite volume method is used to solve the calculation model, and the variation characteristics of internal flow field of external gear pump under different center distance and speed are compared. The results show that the inlet pressure of the gear pump is lower than that of the oil inlet, and the fluid pressure changes periodically. The smaller the center distance between the meshing teeth of the gears is, the larger the average velocity at the outlet is (small) and the greater the pressure difference between the inlet and outlet (small, the higher the pressure in the trapped oil area (low)). A slightly larger center distance can be used to reduce the pressure in the oil-trapped area. 3. Through theoretical analysis, it can be known that the pressure around the gear is circumferential and the hydraulic radial force on the gear is asymmetric, which is verified by numerical simulation. Because of the meshing of two gears, there is an interactive meshing force between the gears, and the meshing force and torque of the gears are calculated. By means of finite element method and ansys software, the meshing contact stress of gears is numerically analyzed, and the stress distribution of gears is obtained, which provides a reference for the design of gears. 4. The design parameters of gear pump are discussed. As long as the number of teeth Z, modulus m and tooth thickness b are determined, the structure of gear pump can be basically determined, and the most important steps in gear pump design are discussed. The main reasons of oil trap are analyzed, and the solution of oil trap is given, that is, the design of unloading tank. According to the calculation method of gear pump radial force, the method of reducing radial force is given. The optimization model of design parameters is established with flow pulsation as the optimization object.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH325

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