基于超磁致伸缩的滚珠丝杠副螺母智能预紧技术及应用研究

发布时间：2018-03-29 14:04

本文选题：超磁致伸缩　切入点：滚珠丝杠副螺母预紧　出处：《山东大学》2017年博士论文

【摘要】：在轴向工作载荷作用下滚珠丝杠副滚珠与滚道处产生的弹性变形,或滚珠丝杠副中存在的轴向间隙,会直接影响滚珠丝杠副的定位或传动精度,并使得滚珠丝杠副的刚度降低。为了消除滚珠丝杠副的轴向间隙,提高其轴向刚度,在滚珠丝杠副承载时,在滚珠丝杠和螺母之间加一预紧结构,并在双螺母之间施加初始载荷,使两者之间产生一定的轴向压力(即预紧力)使得双螺母之间产生轴向变位,以达到减小轴向间隙,提高刚度的目的。预紧力太小,起不到减小间隙和提高刚度的作用,而预紧力过大会使空载摩擦力矩急剧增大,滚动磨损加剧,滚珠丝杠副寿命降低。因此预紧力大小必须控制在一定范围之内。针对目前传统的滚珠丝杠预紧法不能实现预紧力的及时调整问题,深入研究利用功能材料实现滚珠丝杠预紧的机理方法,以提供较大预紧力,并且实现预紧力的准确自动调整,成为精密滚珠丝杠副定位或传动的一个关键科学和技术问题。本文围绕将超磁致伸缩材料(Giant Magnetostrictive Material,简写为GMM)应用于滚珠丝杠螺母预紧这条主线,进行了滚珠丝杆副的预紧力与轴向刚度分析,预紧结构的建模,多物理场参量的检测,超磁致伸缩结构的建模,以及预紧力和静态刚度实验。(1)滚珠丝杠副的轴向刚度取决于丝杠特征,预加载荷和工作条件。鉴于滚珠与滚道之间的摩擦力远小于滚道压力,因此忽略摩擦力的作用。通过分析螺母所受的轴向工作载荷及预紧力与滚道法向力之间的关系以及滚道接触点处的法向变形与螺母相对于丝杠的轴向位移之间的关系,对双螺母定位预紧滚珠丝杠副的刚度进行了分析。(2)从自身结构特点、能量分布、电磁场分析等几个方面对基于超磁致伸缩的三种滚珠丝杠副螺母预紧结构进行了对比,确定了附加铰链-杠杆机构的单个圆柱形GMM构成的预紧结构,对GMM的磁路结构进行了计算和仿真分析,了解GMM磁路中磁场的分布情况,并对预紧用的机械结构进行了多体静力学分析,以保证结构的许用应力、应变及变形。该结构实现了 GMM的机械应变到滚珠丝杠螺母预紧力的传递,预紧力可方便地通过调节GMM的激励电流而进行调整。(3)超磁致伸结构中圆柱形GMM被放置在一个体积有限的腔体空间内,在有限腔体中放置检测线圈获取GMM的磁参量(B,H)时,检测线圈产生的感应磁场与GMM原有的驱动磁场会产生互感,为了尽可能减小互感的影响,获得较为准确的GMM的磁参量,在单线圈获取GMM的B-H曲线基础上,提出了利用亥姆霍兹线圈原理,设计多线圈用于GMM磁参量的检测的方法,并对检测过程进行了仿真分析,结果表明,反串两个亥姆霍兹线圈,在其中间放置检测线圈的检测方法,可以有效减小检测线圈与驱动线圈的互感,比较适用于有限腔体空间内GMM磁通量的检测。(4)以圆柱形GMM为研究对象,对由其构成的超磁致伸缩结构进行设计优化,确定超磁致伸缩结构参数。主要包括GMM几何形状,驱动方式,驱动线圈结构以及预压应力等几个方面。为了提高GMM中磁场的均匀性与线性度,主要考虑驱动方式的优化方法。分析结果表明:在圆柱形GMM上以交替分布的方式施加恒定的偏置磁场,优化磁轭结构,提高了超磁致伸缩材料磁场的均匀性与线性。在准动态条件下,分析超磁致伸缩结构的输出力的特征,通过空载位移和力输出实验,对超磁致伸缩结构的输入输出特性进行了验证。(5)利用所设计的超磁致伸缩结构进行了预紧力的调整和滚珠丝杠静态刚度实验。结果表明,在一定驱动电流范围内,超磁致伸缩结构具有一定的线性工作区,在该工作区内超磁致伸缩结构的压磁方程近似认为是线性的,容易实现预紧力的及时调整。基于超磁致伸缩的滚珠丝杠预紧结构,通过预紧力的调节,可以有效提高滚珠丝杠副的轴向接触刚度,与理论上分析滚珠丝杠副接触刚度的结果是一致的。本文构建了一种附加铰链杠杆的基于超磁致伸缩的滚珠丝杠副螺母预紧系统,提出了一种较为准确的基于亥姆霍兹线圈原理检测GMM中磁场的方法,以及GMM驱动方式的优化方法。本研究实现了将GMM的机械应变转换为滚珠丝杠螺母预紧力,并及时调整滚珠丝杠螺母预紧力的目标,为GMM应用于滚珠丝杠预紧提供了理论和实验基础。
[Abstract]:The effect of axial deformation under the working load of ball screw ball and raceway generated at the elastic, or the existence of ball screw in the axial clearance, will directly affect the ball screw positioning or transmission accuracy, and makes the ball screw stiffness decreased. In order to eliminate the axial clearance of ball screw, the axial rigidity the degree of ball screw bearing, a pre tightening structure between the ball screw and nut, and the initial load is applied between the double nut, causing a certain axial pressure between the two (i.e. preload) makes the axial displacement of the double nut, so as to reduce the axial clearance, improve the stiffness of the. The preload is too small, not to reduce the gap and improve the rigidity of the role, and the pretightening force of Congress to make the no-load friction torque increases rapidly, rolling wear intensifies, reduce the ball screw life. Therefore the pretightening force must be controlled In a certain range. For the timely adjustment problems of ball screw preload method can not be achieved by traditional pretightening force, in-depth study on the realization mechanism of ball screw tightening method using functional materials, to provide a larger preload, accurate automatic adjustment and preload, a precision ball screw positioning or drive a key problem of science and technology. This paper will focus on the giant magnetostrictive material (Giant Magnetostrictive Material, abbreviated as GMM) is applied to the ball screw nuts of the main line, analyzed the stiffness of the ball screw vice pretightening force and axial preload, modeling structure, detection of multi physical field parameters. Modeling of giant magnetostrictive structures, as well as the pretightening force and static stiffness test. (1) the ball screw axial stiffness depends on screw characteristics, pre load and working conditions. In view of the friction between the ball and the raceway The raceway is much smaller than the pressure, thus neglecting friction effect. Through the analysis of the nut by working load and axial pre tightening force and roll to the relation between force and raceway contact points to deformation and nuts with respect to the relationship between the axial displacement of double screw, nut ball screw preload the stiffness was analyzed. (2) the distribution of energy from the structure features, the electromagnetic field analysis of several aspects of the magnetostrictive three ball screw nut tightening structure based on the comparison, determine the pre tightening structure of single cylindrical GMM additional hinge - lever mechanism consisting of the magnetic structure of GMM the analysis and simulation, to understand the distribution of magnetic field in the magnetic circuit of the GMM, and the mechanical structure of the preload are analyzed by multibody statics, in order to ensure the structure of the allowable stress, strain and deformation of the structure is realized. Transfer to the mechanical strain of ball screw nut GMM pre tightening force, pre tightening force can be adjusted conveniently by regulating the excitation current of GMM. (3) super magnetostrictive structure of cylindrical GMM is placed in a limited volume of cavity space, magnetic parameters of the detection coil placed in finite cavity to obtain GMM (B, H), the driving magnetic field induced magnetic field and the original GMM detection coil produces transformer, in order to minimize the influence of mutual inductance, magnetic parameters to obtain more accurate GMM, in the B-H curve based single coil to obtain GMM, proposed by the Helmholtz coil principle, design method for detecting coil GMM magnetic parameters, and the testing process is simulated. The results show that as the two Helmholtz coil, detection method of placing detection coil in the middle, can effectively reduce the detection coil and drive the movable coil transformer, Comparison of detection for GMM flux limited space inside the cavity. (4) cylindrical GMM as the research object, the optimization design of giant magnetostrictive structure composed of the magnetostrictive, determine the structure parameters. Including GMM geometry, drive mode, the drive coil structure, pre stress and other aspects in order to. To improve the GMM magnetic field uniformity and linearity, mainly consider the driving way of optimization methods. The analysis results show that the bias magnetic field in the cylindrical GMM in alternating distribution of applied constant, optimization of magnetic yoke structure, improve the super magnetostrictive material of magnetic field uniformity and linearity. The quasi dynamic conditions, characteristics analysis of the output force of the magnetostrictive structure, the load displacement and force output experiment, the input and output characteristics of giant magnetostrictive structure was verified. (5) the design of ultra magnetostriction structure Adjust the preload and the ball screw static stiffness test. The results showed that in a certain range of driving current, the magnetostrictive structure has a linear region of piezomagnetic equation of magnetostrictive structure in the work area is approximately linear, easy to adjust the preload ball. Screw tightening structure based on magnetostrictive, by adjusting the pretightening force, can effectively improve the axial contact stiffness of the ball screw, and the theoretical analysis results of ball screw contact stiffness is consistent. This paper constructs a magnetostrictive ball screw nut tightening system based on an additional hinge chain lever, puts forward a method of magnetic field detection of GMM based on the principle of Helmholtz coil is more accurate, and the GMM driving mode optimization method. This research realized the mechanical strain of GMM for ball screw The pretightening force of the nut and the timely adjustment of the pre tightening force of the ball screw nut provide the theoretical and experimental basis for the application of GMM to the ball screw pretightening.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TH132

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