内燃式水平对动空气压缩机平衡设计及多工况动力学仿真研究

发布时间：2018-06-02 07:45

本文选题：内燃式空气压缩机 + 平衡　；参考：《青岛大学》2017年硕士论文

【摘要】：内燃式水平对动空气压缩机将内燃机与空气压缩机组合成一个整体,并通过内燃机产生的热能来转化为空气压缩机的气体压力能,是一种新型的压气装置。目前存在的双拐对称布置的内燃式水平对动空气压缩机方案,记为方案1,由于存在惯性力系中的不平衡力矩成分,仍会引起些许整机的振动问题。因此,针对内燃式水平对动空气压缩机的动不平衡问题,提出了一种三拐对称布置的内燃式水平对动空气压缩机方案,记为方案2。并针对这两种方案,进行了分析及对比研究,主要的研究内容如下:应用解析法分别对两种方案进行了计算分析,结果表明:在添加平衡块的前提下,方案1有旋转惯性力、旋转惯性力矩、一阶往复惯性力达到了平衡状态,而相比方案1,方案2不仅有以上惯性力和力矩达到了平衡状态,其一阶往复惯性力矩也达到了平衡状态。故方案2的内燃式水平对动空气压缩机处于外部平衡状态,其综合平衡性能要优于方案1的。应用逐个平衡法在方案2曲轴的每个曲拐的每个曲柄臂上安装了一块平衡块。经计算分析,确定了方案2曲轴两端的每个平衡块质量为0.153,偏心距为15.92;中间的每个平衡块质量为0.276,偏心距为17.38。应用ADAMS分别对两种方案的虚拟样机进行仿真分析,结果表明:三种工况(曲轴平均转速分别为1500、2000、2400)下方案1的最大主轴承平均受力载荷为2228N,而方案2的最大主轴承平均受力载荷为为1956N。按照轴承平均载荷最小这一平衡目标可知,方案2的平衡性能要优于方案1的。应用ANSYS Workbench对方案2曲轴进行了有限元静力学分析和模态分析。其中,有限元静力学分析结果表明:曲轴的最大等效应力位于曲柄销与曲柄臂连接圆角处,其最大值为305.09,小于曲轴材料球墨铸铁QT700-2的许用应力,证明了曲轴的设计满足强度设计的要求;曲轴的变形主要分布在平衡块处,其最大变形量为0.417,属于小变形,证明了曲轴的设计满足刚度设计要求。模态分析结果表明:曲轴最大振幅的部位出现在曲柄销、曲轴端面以及平衡块上;曲轴约束模态的固有频率相比其自由模态的较大,其最低固有频率为628.42,明显高于内燃式水平对动空气压缩机在实际工作时的基频(曲轴平均转速为2400,对应的基频为40),使曲轴有效地避免了共振现象的发生,证明了曲轴的动态性能满足设计要求。
[Abstract]:The internal combustion horizontal counteraction air compressor combines the internal combustion engine and the air compressor into a whole and converts the heat energy generated by the internal combustion engine into the gas pressure energy of the air compressor. It is a new type of pressure device. The scheme of internal combustion horizontal counteracting air compressor with symmetrical arrangement of double crutches is recorded as scheme 1. Due to the existence of unbalanced torque in the inertial force system, the vibration problem of the whole machine will still be caused. Therefore, aiming at the dynamic unbalance of the internal combustion horizontal counteracting air compressor, this paper puts forward a scheme of the internal combustion horizontal counteracting air compressor arranged symmetrically with three turns, which can be described as scheme 2. The main contents are as follows: the analytical method is used to calculate and analyze the two schemes respectively. The results show that: under the premise of adding balance block, scheme 1 has rotary inertia force. The rotational inertia torque and the first order reciprocating inertia force reach the equilibrium state. Compared with the scheme 1, scheme 2 not only has the above inertia force and torque to achieve the equilibrium state, but also the first order reciprocating inertia moment has reached the equilibrium state. Therefore, the internal combustion horizontal compressor of scheme 2 is in external equilibrium state, and its comprehensive balance performance is better than that of scheme 1. A balance block is mounted on each crank arm of each crank of the crankshaft of scheme 2 using the method of balancing one by one. Through calculation and analysis, it is determined that the mass of each balancing block at both ends of the crankshaft in scheme 2 is 0.153, the eccentricity is 15.92, and the mass of each balancing block in the middle is 0.276 and the eccentricity is 17.38. The virtual prototype of the two schemes is simulated and analyzed by ADAMS. The results show that under the three conditions (the average speed of crankshaft is 1500g / 2000 / 2400), the average load of the main bearing is 2228Nin the first scheme, and the average load of the main bearing in the second scheme is 1956N. According to the balance goal of minimum average load of bearing, the balance performance of scheme 2 is better than that of scheme 1. The finite element static analysis and modal analysis of scheme 2 crankshaft are carried out by ANSYS Workbench. The results of finite element static analysis show that the maximum equivalent stress of the crankshaft is at the corner of the crank pin and the crank arm, and its maximum value is 305.09, which is less than the allowable stress of the crankshaft ductile iron QT700-2. It is proved that the design of crankshaft meets the requirement of strength design, and the deformation of crankshaft is mainly distributed at the balance block, and its maximum deformation is 0.417, which belongs to small deformation. It is proved that the design of crankshaft meets the requirement of rigidity design. Modal analysis results show that the position of maximum amplitude of crankshaft appears on crank pin, crankshaft end face and balance block, and the natural frequency of crankshaft restrained mode is larger than that of free mode. The minimum natural frequency is 628.42, which is obviously higher than that of the internal combustion horizontal counteracting air compressor in actual operation (the average speed of crankshaft is 2400 and the corresponding fundamental frequency is 40), which makes the crankshaft avoid resonance phenomenon effectively. It is proved that the dynamic performance of the crankshaft meets the design requirements.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH45

【参考文献】