小型数控车床纵向进给机构的设计

小型台式数控车床Z轴进给系统设计,是以步进电动机、减速装置、滚珠丝杠副组成的开环控制系统,控制定位精度为±0.01 mm.主要阐述的是滚珠丝杠副、导轨副、轴承等的选择计算,确保机械部件的高精度、高刚度、高强度,使之满足数控系统的要求;并计算选择步进电机,确保伺服系统能够实现转矩、速度、位置的精确控制.     

中日数控机床滚珠丝杠副精度等级标准差异现状分析

采用JIS B 1192—1997《日本工业标准题录：机械卷J51系列机床零部件部分》与我国GB/T 17587.3—1998《滚珠丝杠副第3部分：验收条件和验收检验》技术指标对比分析法,分析了两国对精密丝杠的3个检测项目：有效行程内允许行程变动量,任意300 mm行程内允许的行程变动量以及2π弧度内允许的行程变动量。分析结果表明：我国1级精度标准的精密丝杠比日本同级别的丝杠平均低1.4μm,我国滚珠丝杠公称直径在125～200 mm范围内缺少丝杠支撑轴径端面1级圆跳动精度标准,螺母外径在250～500 mm范围内缺少1级、2级精度圆跳动精度标准。我国目前尚缺少中大直径滚珠丝杠精度等级标准规范,依赖于国外标准。     

产品创新引领市场 夯实基础降本增效

产品创新,生产装备必须至臻 公司在近几年来,先后在CIMT2009北京中国国际机床展上,推出中空冷却滚珠丝杠副和螺母旋转型滚珠丝杠副;2010年南京中国数控机床展上推出直径160mm、L=14m无拼接重载研磨滚珠丝杠副为国内首创;55HRC和165HRC高刚度、重载型精密滚动直线导轨副     

滚珠丝杠副性能指标的测试与研究

精度指标与性能指标是滚珠丝杠副两大指标,目前国产滚珠丝杠副普遍存在着性能指标落后精度指标.为满足高档数控机床对滚珠丝杠副的要求,山东博特公司研制开发了多种滚珠丝杠副综合性能测量仪器,开展了滚珠丝杠副速度、加速度、温升、热位移、噪声、静刚度、摩擦力矩等性能指标的测量与研究.     

数控机床滚珠丝杠副的系统刚度分析与研究

为提高滚珠丝杠的静态和动态稳定性.以南京工艺装备制造有限公司内循环垫片预紧法兰螺母FFZD型滚珠丝杠副为研究对象,分析了数控机床滚珠丝杠副的系统刚度,这对于丝杠的精度、寿命、疲劳等特性具有一定的借鉴意义.文中分别分析了滚珠丝杠的拉压刚度、支撑轴承刚度、轴向刚度在预紧前后发生的变化.分析结果表明:预紧后比预紧前的滚珠丝杠轴向刚度最大可高出47％.最后得出结论:螺母位置决定滚珠丝杠系统刚度的大小.当螺母朝着丝杠两端移动时,则丝杠系统刚度会随着自身直径增大而明显增大,而当螺母朝着丝杠中点位置移动时,则此时丝杠系统刚度会随自身直径增大而变化不明显.     

机床数控化改造中滚珠丝杠的选型及定位误差计算

数控机床进给传动系统的传动精度和刚度主要取决于滚珠丝杠螺母副的传动精度及其支撑结构的刚度，丝杠的直径、支撑、预紧影响系统刚度，丝杠螺母及其支撑部件之间的间隙影响传动精度。因此，在机床数控化改造中，应主要解决滚珠丝杠的选型及预紧计算。本文以M28125轴承磨床数控化改造为例，着重介绍纵向滚珠丝杠的选型计算。     

滚珠丝杠副在工业中的应用

北京霹西自动化技术有限公司是专营滚珠丝杠副以及采用滚珠丝杠和齿形带为基本构件的直线运动单元的专业公司。十余年来,为客户提供德国NEFF公司生产的冷轧或磨削滚珠丝杠,直径从16～80mm,导程5～50mm,各类丝杠最大长度可     

滚珠丝杠副的选型计算与应用

在数控机床的设计中,为了满足数控机床高进给速度、高定位精度、高平稳性和快速响应的要求,必须合理选择滚珠丝杠副。滚珠丝杠的选择主要包括精度、尺寸规格（包括导程与公程直径）、承载能力、支承方式等几个方面的内容。除此之外,还应对其进行必要的校核计算,如对细长而又承受压缩载荷的滚珠丝杠应作压杆稳定性核算;对转速较高,支承距离大的滚珠丝杠副应作临界转速校核;对精度要求高的滚珠丝杠应作刚度校核等。     

滚珠丝杠副的特性和技术动向

滚珠丝杠副是精密、高效的传动元件,本文介绍了此种丝杠副的技术特性。其传动效率高达85%-90%,为普通丝杠副的2-4倍;使用寿命为滑动丝杠副的4-10倍;而且进给精度和重复定位精度高、同步性好。本文还介绍了国内外生产的滚珠丝杠副向高精度化、规格多样化(微型化和大型化)、转速高速化和产品标准化发展的情况。     

微型滚珠丝杠副的设计与制造

通常滚珠丝杠副的名义直径小于16mm以下时,称为微型滚珠丝杠副。当丝杠名义直径小于10mm时,则制造更加困难,关键是螺母的内孔小,滚道无法进行磨削。在滚珠循环结构设计上,采用螺旋槽式自体内循环和导管式外循环两种结构,我们都进行了研制,比较了他们的制造工艺和产品优劣。螺旋槽式结构紧凑,回珠孔加工精度要求高,孔中心对螺母滚道中心位置度误差不大于0.03mm。当孔位与滚道接触平滑,总装时,仍发现滚珠运动不畅,产品总体性能不好。插管式外循环结构,除导管不易制造外,螺母制造大体与螺旋槽式相同(见图1)。     

Design of high-precision ball screw based on small-ball concept

This paper addresses a design method of ball screws for high-precision feed drives of machine tools. The torque fluctuation of a ball screw influences position deviation, which deteriorates the contorting accuracy. The torque fluctuation comes from the load change of the contacting balls between the nut and the screw shaft during ball circulation. In order to decrease the load change, a ball screw that employs smaller balls was designed and evaluated in the measurement tests. The experimental results showed that the designed ball screw could decrease both the torque fluctuation and position deviation.     

小型数控雕刻机控制系统设计

小型数控雕刻机采用常见的开环数控系统。开环数控系统通常由步进电动机控制,其原理是通过数控装置发出进给脉冲,经功率放大后,驱动步进电动机转动1个步距角,再经减速齿轮带动丝杠旋转,并通过丝杠和螺母副传动,使工作台产生相应的位移。开环控制系统的精度较低,速度也较低;但是其结构简单,易于调试,目前在简易型、经济型数控系统中采用。数控雕刻机在机械加工工业上有着重要的地位,其相关性研究已成为国内外的热点。     

Haptic controlled three-axis MEMS gripper system

In this work, we describe the development and testing of a three degree of freedom meso/micromanipulation system for handling micro-objects, including biological cells and microbeads. Three-axis control is obtained using stepper motors coupled to micromanipulators. The test specimen is placed on a linear X-stage, which is coupled to one stepper motor. The remaining two stepper motors are coupled to the Y and Z axes of a micromanipulator. The stepper motor-micromanipulator arrangement in the Y and Z axes has a minimum step resolution of ～0.4?μm with a total travel of 12 mm and the stepper motor-X stage arrangement has a minimum resolution of ～0.3?μm with a total travel of 10 mm. Mechanical backlash error is ～0.8?μm for ～750?μm of travel. A MEMS microgripper from Femtotools? acts as an end-effector in the shaft end of the micromanipulator. The gripping ranges of the grippers used are 0-100?μm (for FT-G100) and 0-60?μm (for FT-G60). As the gripping action is performed, the force sense circuit of FT-G100 measures the handling force. This force feedback is integrated to a commercially available three degree of freedom haptic device (Novint Falcon) allowing the user to receive tactile feedback during the microscale handling. Both mesoscale and microscale controls are important, as mesoscale control is required for the travel motion of the test object whereas microscale control is required for the gripping action. The haptic device is used to control the position of the microgripper, control the actuation of the microgripper, and provide force feedback. A LABVIEW program was developed to interlink communication and control among hardware used in the system. Micro-objects such as SF-9 cells and polystyrene beads (～45?μm) are handled and handling forces of ～50?μN were experienced.     

一种微位移促动器的设计和检测

设计制造了一套微位移促动器并进行了检测。比较了常用的实现高精度、大行程的微位移机构的工程方法,并结合大天区面积多目标光纤光谱天文望远镜(LAMOST)微位移调节机构的实现原理,采用步进电机驱动减速器、精密丝杆型式,及高精度的杠杆缩放结构,实现了高精度、大行程的微位移促动器。根据该传动机构的特点,对机构的误差进行了分析,通过计算机查表校正丝杆的传动误差。双频激光干涉仪的检测结果表明该微位移促动器在行程范围内灵敏度达到了201 nm±48 nm,步长为10 μm,单向精度达到了标准偏差237 nm。     

An improved accuracy-measuring method in manufacturing the lead screw of grating ruling engine

A measuring method was studied to further improve the manufacturing accuracy of the lead screw. Firstly, factors that can axially displace the screw shaft were analyzed and a relationship between factors and axial displacement was given. The axial displacement of the screw shaft was measured using a laser interferometer, and results show that the variation amplitude of the screw-shaft axial displacement was about 80 nm while the variation period was consistent with the rotation period of the screw shaft. Next, two methods of measuring the manufacturing accuracy of the lead screw were considered: a traditional method that measures the absolute position of the nut and an improved method that measures the displacement between the nut and screw shaft. A No. 4 screw shaft was manufactured under the guidance of results obtained using the improved measuring method. Experimental measurements were then made; results show that the pitch displacement errors obtained using the traditional and improved measuring methods were 0.6 and 0.4 μm, respectively, indicating that the improved measuring method is more exact. Finally, an echelle grating ruled by a grating ruling engine that used the No. 4 screw shaft as a macro-positioning element was introduced. Its excellent parameters indirectly show that the improved measuring method has better accuracy.     

数控电火花机床滚珠丝母的改造

数控电火花机床上的滚珠丝母损坏后,丝杠完好,厂家不单独提供丝母,只能成套购买,造成资金浪费。为解决这一问题,对滚珠丝母进行了改造,保证了机床精度,节约了资金。     

基于蠕滑理论的精密滚珠丝杠副摩擦力研究

考虑不同相位角处滚珠所受离心力及摩擦力的影响,建立了双螺母预紧式滚珠丝杠副多自由度动力学模型,该模型不再基于所有滚珠受力相等和运动相同的假设,使用蠕滑力模型来表征滚珠与滚道接触界面间的摩擦力;利用经验模态分解（EMD）包络分析方法进行了滚珠丝杠副振动信号撞击频率的提取,与理论计算结果进行对比,对动力学模型进行了验证;分析了丝杠转速、轴向载荷、滚道曲率比和导程对滚珠丝杠副摩擦力的影响规律。     

数控轴承磨床进给传动系统刚度分析

通过分析数控磨床进给滚珠丝杠刚度的影响因素，提出了选用滚动体数目多且增大接触角的大刚度丝杠专用轴承；应用大直径螺栓并严控制其伸出长度；预紧螺母预紧力约为最大轴向载荷的1／3等改进磨床进给伺服机构性能的建议。     

High-precision radius measurement of ball indenter

To solve the problem of calibrating the radius of a ball indenter in a hardness tester, a laser confocal radius measurement and calibration method for the ball indenter is proposed without separating the ball from the body of the indenter. The laser confocal radius measurement and calibration method uses the maximum of the confocal axial intensity curve to precisely identify the cat’s eye and confocal position of the test ball indenter. The distance between these two positions is then measured to achieve high-precision radius measurement. The theoretical analyses and experimental results indicate that the radius measurement uncertainty of the ball indenter with a diameter of 1.5875 mm is within 0.12 μm.     

几何误差和倾覆力矩对双螺母滚珠丝杠副载荷分布的影响#br#

建立了一种考虑几何误差（滚珠尺寸误差、丝杠导程误差和滚道齿形误差）和倾覆力矩的双螺母滚珠丝杠副载荷分布模型;通过试验测得4010型滚珠丝杠副的力与位移变形曲线,验证了理论模型的正确性;通过仿真分析研究了轴向外载荷、几何误差和倾覆力矩对双螺母滚珠丝杠副载荷分布的影响。研究结果表明：轴向外载荷一定时,倾覆力矩会导致双螺母滚珠丝杠副的载荷分布迅速变差;滚珠尺寸误差和滚道齿形误差会使双螺母滚珠丝杠副中滚珠的受载显著增大或减小;由于丝杠轴向误差累计的作用,导程误差会使双螺母滚珠丝杠副中一侧螺母受载增大,另一侧螺母受载减小;在误差大小一定的情况下,导程误差对载荷分布的影响程度大于尺寸误差和齿形误差,即双螺母滚珠丝杠副的载荷分布对导程误差的敏感度更高。