高速螺母驱动型滚珠丝杠副动力学特性研究

发布时间：2018-03-22 23:05

本文选题：螺母驱动型滚珠丝杠副　切入点：进给系统　出处：《山东大学》2013年博士论文　论文类型：学位论文

【摘要】：数控机床的大型化和高速化,不但要求机床主轴转速不断提高,而且进给速度也要求越来越快。常规的滚珠丝杠副,尤其是大型、重型高档数控机床用的大行程丝杠副,自身重量较螺母大得多,因此丝杠旋转惯性力很多,导致发热、变形和能耗严重,变形的丝杠在旋转过程中又会产生振动和噪声,降低了设备的工作精度。这是目前一个亟待解决的问题。因此本研究根据运动的相对性,提出新型“螺母驱动型滚珠丝杠副”,把传统的“丝杠驱动方式”改为“螺母驱动方式”。本研究借助于数学建模、力学分析、计算分析软件和实验研究等方法,在构建滚动体运动学、接触模型及进给系统结构动力学模型基础上,对螺母驱动型滚珠丝杠副高速传动性能进行研究,研究内容主要包括： 1.根据运动学理论,对高速螺母驱动型滚珠丝杠副滚动体运动学进行分析。求解了滚珠滚动速度与驱动螺母轴转速之间的运动关系,推导出滚动体公转和自转角速度,求取双螺母内滚动体接触点位置及滑动速度。理论分析得出相同驱动速度时螺母驱动型滚珠丝杠副滚动体公转和自转角速度低于传统的丝杠驱动型滚珠丝杠副滚动体公转和自转角速度。 2.根据Hertz接触理论,对高速螺母驱动型滚珠丝杠副滚动体接触特性进行分析。建立了轴向载荷、惯性效应、位移约束联合作用下的高速螺母驱动型滚珠丝杠副接触分析模型,应用迭代法求解非线性方程组,分析了不同转速和轴向力等工况下滚珠丝杠副接触参数的变化规律。根据理论计算求取系统进给加速度。结果表明滚珠丝杠副高速运动时,螺母组件内接触角、法向载荷以及弹性变形随转速和轴向载荷的变化而变化。与丝杠驱动型相比采用相同额定转矩电机驱动,螺母驱动型滚珠丝杠副降低了传动系统转动惯量,进而降低系统驱动能耗,螺母驱动型滚珠丝杠副可获得更高进给加速度,更具有高速性。 3.对预紧力可调的双螺母驱动型滚珠丝杠副进给系统进行结构动力学分析,首先建立滚珠丝杠副结构动力学模型。分析了预紧力的变化对固有频率的影响规律,主要设计参数的变化对系统低阶固有频率的影响。结果表明,进给系统固有频率具有时变性。与传统的丝杠驱动型相比,采用螺母驱动型滚珠丝杠副,提高了进给系统低阶固有频率,可使系统具有更宽的通频带,提高系统的速度环增益和位置环增益,从而提高整个系统的快速响应能力和加工精度。 4.建立了摩擦力矩的分析模型,分析了滚珠丝杠副摩擦力矩的产生机理。研究轴向载荷、轨道制造误差等对摩擦力矩的影响,分析了摩擦力知低频波动的原因。运用弹流动力润滑理论分析滚珠丝杠副的润滑状态。结果表明轴向载荷、滚道波纹度是对摩擦力矩波动性影响很大。 7.研制了螺母驱动型滚珠丝杠副并实际应用,借助超长轴键槽铣削机床对螺母驱动型滚珠丝杠副和丝杠驱动型滚珠丝杠副进行了振动响应实验和温升测试实验。实验研究表明螺母驱动型滚珠丝杠副系统第一阶固有频率大于丝杠驱动型滚珠丝杠副第一阶固有频率,在相同工作环境下丝杠驱动型滚珠丝杠副传动机构丝杠温升总体大于螺母驱动情况下丝杠的温升。本研究为高速精密滚珠丝杠副的设计、制造提供了理论和技术支持,为研制开发具有完全自主知识产权的高速精密滚珠丝杠副指出了一条切实可行的途径,对提高我国数控机床的制造水平有较大的理论意义和实际应用价值。
[Abstract]:Large scale and high speed CNC machine tool, not only requires the spindle speed increases, and the feed speed is faster and faster. The conventional ball screw, especially large, Heavy CNC machine tools with large stroke screw, nut weight itself is much larger, so the screw rotation inertia force, causing fever the deformation and energy consumption, serious deformation of the screw will generate vibration and noise in the rotation process, reduces the operation precision of the equipment. It is an urgent problem to be solved at present. Therefore this research based on the relativity of motion, a new type of ball screw nut drive ", the traditional" screw drive "to" drive nut. "
This study applies mathematical modeling, mechanical analysis, calculation and analysis method of software and experimental research, in the construction of the rolling body kinematics, contact dynamics model and based on the structure model of the feed system, the performance of ball screw nut driving type high speed transmission is studied, the main contents of the study include:
1. according to the kinematics theory of high speed ball screw nut drive type rolling body kinematics analysis. To solve the motion relationship between the rolling speed and driving screw shaft speed, roller revolution and rotation velocity is derived for the double nut rolling contact point position and sliding velocity. The theoretical analysis shows that the same drive speed nut driven ball screw roller revolution and rotation rate lower than the traditional screw driven ball screw roller revolution and rotation.
2. according to the Hertz contact theory of high speed ball screw nut driven rolling contact characteristics were analyzed. The establishment of axial load, inertial effect, type of ball screw nut with contact analysis model of high speed displacement constraints drive, using iterative method to solve nonlinear equations, analyzed the variation of contact parameters of ball the screw speed and the axial force in different conditions. According to the theoretical calculation for the system acceleration. The results show that the deputy high speed ball screw, nut assembly inner antennae, normal load and elastic deformation change with speed and axial load change. Compared with the same type and screw drive rated torque motor drive, drive nut type of ball screw drive system reduces the moment of inertia, thereby reducing the energy consumption of driving system, type of ball screw can obtain higher feed drive nut Degree, more high speed.
3. of the double nut with adjustable preload type ball screw drive side feed system structure dynamics analysis, firstly, the ball screw structure dynamics model. Analyzed the influence of variation of pretightening force on the natural frequency of the influence of the main design parameters of the low order natural frequencies of the system. The results show that the feed system the natural frequency is time-varying. Compared with the traditional screw driven by ball screw nut drive type, improve the low order natural frequency feed system, the system has a wider bandwidth, improve the system speed loop gain and position loop gain, so as to improve the ability of quick response and processing precision of the whole system.
4. establish the analysis model of friction torque, analyzes the produce mechanism of ball screw friction torque. On axial load, the impact of rail manufacturing errors of the friction torque, analyzes the reasons that low frequency fluctuation of friction. By using the theory of Elastohydrodynamic Lubrication Analysis of lubrication of ball screw. The results show that the axial load, raceway waviness is a great influence on the friction torque fluctuation.
7. developed driven ball screw nut and the practical application, with long shaft keyway milling machine for nut driven ball screw and screw driven ball screw vibration test and temperature rise test. Experimental results show that the type of ball screw nut driving system of the first order natural frequency is greater than the screw type ball screw drive Deputy First Order natural frequency, in the same working environment type screw driven ball screw drive mechanism screw nut drive temperature is greater than the overall situation of the screw temperature rise.
This study for the design of high speed and high precision ball screw, provides theoretical and technical support for manufacturing, research and development with independent intellectual property rights of high speed and high precision ball screw points out a feasible way, has great theoretical significance and practical application value to improve the level of NC manufacturing.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH113;TG659

【参考文献】