高压内啮合齿轮泵关键技术研究

发布时间：2019-04-24 03:14

【摘要】：内啮合齿轮泵具有结构紧凑、运转平稳、压力高、噪声低、无困油、自吸性好、转速范围广等突出优点而被广泛用于各类工程机械。而高压化是内啮合齿轮泵发展趋势。但随着压力增加，将导致零件之间摩擦发热、油液泄漏及零件的变形量增加。本文对影响内啮合齿轮泵高压化的关键技术问题进行了分析研究。内啮合齿轮泵中的内齿轮受到高压油的液压力和齿轮啮合力的作用，内齿轮外壁对泵体产生较大压力，增加了内齿轮与泵体内壁之间的摩擦,使内齿轮与泵体发生胶合失效。本文运用静压支撑理论，通过对内齿轮及泵体的受力理论分析及FLUENT数值模拟，，得到使内齿轮达到受力平衡的静压支撑槽的位置及角度等关键参数，根据参数进行样机实验，实验结果验证了其可行性。内齿轮泵在高压情况下齿轮的径向端面和轴向端面都会出现较大泄漏。为减少高压内啮合齿轮泵径向泄漏量，需进行径向补偿。通过对月牙块受力随齿轮转动角度变化作动态分析，优化得到使用于径向补偿的上下两月牙块分别贴紧内外齿轮齿顶形成径向密封的情况下，上下月牙块对内外齿轮压力最小的上下月牙块高压区端面角度和密封小棒安装角度等参数。轴向泄漏采用浮动侧板进行轴向补偿。而浮动侧板两侧受到的压油腔内高压油和背压室高压油对其作用力的力矩不平衡，浮动侧板由此将发生歪斜、侧翻，加剧齿轮泵齿轮轴向端面与浮动侧板间磨损，从而降低齿轮泵的寿命。此外，浮动侧板两侧的作用力将决定浮动侧板与外齿轮和内齿轮间的轴向间隙和由其产生的泄漏，直接影响泵的容积效率。本文通过计算得到使浮动侧板所受轴向力和力矩平衡的背压室边界极角和背压室边界内外圆半径。内啮合齿轮泵内部零件之间有配合间隙，在高压条件下，流体由此产生泄漏，并且对与之接触的零件表面产生流体摩擦阻力，流体泄漏量和流体摩擦阻力都与零件表面粗糙度相关。通过分析粗糙度对流体泄漏和摩擦阻力的影响，得到使流体在两表面之间泄漏量、流体摩擦阻力最小的最优粗糙度。高压油对外齿轮径向齿面的油压力会使外齿轮产生变形，影响外齿轮尺寸，对内啮合齿轮泵的流量产生影响。通过计算外齿轮由高压油产生的变形量，将外齿轮段挠度变形看做外齿轮产生的变位系数，得到外齿轮挠度变形前后齿轮泵流量之差。
[Abstract]:With the advantages of compact structure, stable operation, high pressure, low noise, no oil trap, good self-priming and wide rotating speed range, internal meshing gear pump is widely used in all kinds of construction machinery. High pressure is the development trend of internal meshing gear pump. However, with the increase of pressure, friction heat between parts, oil leakage and deformation of parts will increase. In this paper, the key technical problems affecting the high pressure of internal meshing gear pump are analyzed and studied. The inner gear in the internal gear pump is affected by the hydraulic pressure of the high pressure oil and the meshing force of the gear. The inner gear and the outer wall of the pump produce a greater pressure on the pump body, which increases the friction between the inner gear and the pump body, and makes the internal gear and the pump body glued to failure. Based on the theory of static pressure support and the theoretical analysis of internal gear and pump body and the numerical simulation of FLUENT, the key parameters such as the position and angle of static pressure support groove to achieve the force balance of internal gear are obtained in this paper, and the prototype experiment is carried out according to the parameters. The experimental results show that this method is feasible. Under high pressure, both radial and axial end faces of the inner gear pump will appear large leakage. In order to reduce the radial leakage of high pressure internal meshing gear pump, radial compensation should be carried out. Based on the dynamic analysis of the force of the crescent mass with the rotation angle of the gear, the radial seal is obtained when the upper and lower two-month pieces used for radial compensation are respectively attached to the top of the inner and outer gears to form a radial seal. The upper and lower crescent mass has the lowest pressure on the inner and outer gears, such as the end angle of the high pressure area of the upper and lower crescent mass and the installation angle of the sealing rod. Axial leakage is compensated by floating side plate. On both sides of the floating side plate, the torque of the high pressure oil in the pressure chamber and the high pressure oil in the back pressure chamber is unbalanced, so the floating side plate will be skewed and turned over, which aggravates the wear between the axial face of the gear pump gear and the floating side plate. Thus reducing the life of gear pump. In addition, the force on both sides of the floating side plate will determine the axial clearance between the floating side plate and the outer gear and the inner gear, and the leakage will directly affect the volume efficiency of the pump. In this paper, the polar angle of the back pressure chamber boundary and the radius of the inner and outer circles of the back pressure chamber boundary to balance the axial force and torque of the floating side plate are obtained by calculation. There is a fit gap between the internal parts of the internal meshing gear pump. Under high pressure conditions, the fluid leakage occurs and a fluid friction resistance is produced on the surface of the part with which it is in contact. The fluid leakage and friction resistance are related to the surface roughness of the parts. By analyzing the influence of roughness on fluid leakage and friction resistance, the optimum roughness is obtained, which makes the fluid leak between two surfaces and the friction resistance of fluid is minimized. The oil pressure of high pressure oil on the radial tooth surface of the outer gear causes the deformation of the outer gear, affects the size of the outer gear, and affects the flow rate of the internal meshing gear pump. By calculating the deformation of the outer gear caused by the high pressure oil, the deflection of the outer gear segment is regarded as the displacement coefficient of the outer gear, and the difference of the flow rate of the gear pump before and after the deflection deformation of the outer gear is obtained.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH325

【参考文献】