双变量对称式液压变压器的特性分析

发布时间：2018-03-22 13:31

本文选题：液压变压器　切入点：双变量对称式结构　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：液压变压器作为恒压网络二次调节技术的关键液压元件,对液压系统的柔性控制、高效节能具有重要意义。由于其恒功率调节特性,备受国内外学者关注,但是仍存在一些不足之处。现有技术中存在的轴向力和径向力分布不均匀现象,严重影响了配流盘的平衡,将会导致烧盘现象的发生;同时还会产生噪声,降低了液压变压器的使用寿命。为了解决上述问题,设计了一种双变量对称式液压变压器。建立其数学模型,并通过CFD仿真验证该模型的正确性。对双变量对称式液压变压器的系统构成进行了相关介绍,依据其结构特性,根据两侧斜盘倾角是否相同、两侧缸体是否完全对称及存在偏角大小情况,还有配流盘转角和缸体转角等因素的不同组合情况,对双变量对称式液压变压器的平均流量、瞬时流量、流量脉动、平均扭矩、瞬时扭矩和变压比等特性进行建模仿真分析。通过分析得出了它们与各影响因素之间的对应关系,瞬时流量的影响因素有配流盘转角、缸体偏角和两侧斜盘倾角等,配流盘转角影响其跳跃量,缸体偏角影响其跳跃现象发生的时刻,斜盘倾角影响其幅值大小。当不考虑缸体偏角时,流量脉动率仅与配流盘转角及柱塞数有关;当考虑缸体偏角时,流量脉动率还与两侧斜盘倾角对应关系有关。通过调节相关量实现对流量特性的控制。液压变压器变压比与配流盘旋转角度、T口压力以及摩擦扭矩等因素有关,随着配流盘转角的增大,变压比增大;对于T口压力的变化,变压比大于1时二者正相关,小于1时二者负相关;而随着摩擦转矩的增大,变压比减小。通过前期仿真分析得到的这些结论将为后续进一步的研究及仿真分析提供基础。在后续研究中,对液压变压器内部流场进行分析,通过数值仿真试验可知,斜盘倾角只改变瞬时流量的幅值,对其变化趋势没有影响,而缸体偏角改变瞬时流量周期内的变化阶段。通过对以上角度的合理选取可以改善液压变压器的脉动现象。数值仿真试验数据符合所建立的数学模型,故而验证了该数学模型的正确性。
[Abstract]:As a key hydraulic component in the secondary regulation technology of constant voltage network, hydraulic transformer is of great significance to the flexible control of hydraulic system and high efficiency and energy saving. Because of its constant power regulation characteristic, it has attracted the attention of scholars at home and abroad. However, there are still some shortcomings. The uneven distribution of axial and radial forces in the prior art has seriously affected the balance of the distribution disk, which will lead to the occurrence of the phenomenon of burning the disk, and also produce noise. The service life of hydraulic transformer is reduced. In order to solve the above problems, a kind of double variable symmetrical hydraulic transformer is designed, and its mathematical model is established. And the correctness of the model is verified by CFD simulation. The system structure of the bivariate symmetrical hydraulic transformer is introduced. According to its structural characteristics and whether the inclination angle of the two sides of the inclined disk is the same or not, Whether the two sides of the cylinder block is completely symmetrical or not and whether the deflection angle exists, as well as the different combinations of factors such as the rotating angle of the distributor and the cylinder block, etc., for the average flow rate, instantaneous flow rate, flow pulsation, average torque of the two-variable symmetrical type hydraulic transformer, The characteristics of instantaneous torque and variable-pressure ratio are modeled and simulated. The corresponding relations between them and the influencing factors are obtained. The influence factors of instantaneous flow rate are the rotating angle of the distribution disk, the deviation angle of the cylinder block and the inclination angle of the two sides of the inclined disk, etc. The angle of flow distribution plate affects the jump, the angle of cylinder block affects the time when the jump occurs, and the angle of inclination of inclined disk affects the amplitude. When the angle of cylinder block deviation is not considered, the rate of flow pulsation is only related to the angle of flow distribution disc and the number of plunger. When the cylinder block deflection angle is considered, The flow pulsation rate is also related to the corresponding relationship between the obliquity angle of the two sides of the inclined disk. The flow characteristic is controlled by adjusting the correlation quantity. The variable voltage ratio of the hydraulic transformer is related to the rotating angle of the distributor and the friction torque, and so on. With the increase of the rotating angle of the distribution disc, the VV ratio increases; for the variation of the T port pressure, the VV ratio is positively correlated with the change of the T port pressure, and is negatively correlated with the variation of the T port pressure, and is negatively correlated with the friction torque. These conclusions will provide a basis for further research and simulation analysis. In the follow-up study, the flow field of hydraulic transformer is analyzed, and the numerical simulation results show that, The tilting angle only changes the amplitude of instantaneous flow, and has no effect on the trend of change. The variation stage of cylinder block deflection angle is changed in the instantaneous flow period. The pulsation phenomenon of hydraulic transformer can be improved by reasonable selection of the above angles. The numerical simulation results agree with the established mathematical model. Therefore, the correctness of the mathematical model is verified.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137.5

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