油缸孔波纹的消除方法

在加工汽车起重机的油缸时,孔内壁容易产生波纹缺陷,成为生产上的技术关键。为了提高油缸孔内壁质量,拟定了油缸孔内壁的加工方法。一、现场加工工艺分析１．加工对象油缸内孔直径为　１１０～２００ｍｍ,油缸长度为６．５－９ｍ,油缸材质为４５钢和ＳＴＥ４７高强度进口钢,正火硬度分别为ＨＢ１８０－２２０、ＨＢ２２２－２６３,孔内壁表面粗糙度Ｒａ０．４μｍ,圆度为０．０２９ｍｍ,内孔公差为Ｈ８。２．油缸孔加工工装油缸孔加工采用一次镗－铰－滚压成形,工装是粗镗刀与镗杆用可调固定连接,精镗刀与镗杆是浮动连接,在加工…     

专用圆锥滚子轴承30214X2A／HA装配高超差分析

３０２１４Ｘ２Ａ／ＨＡ轴承用于某变速箱,其设计参数如下：外滚道尺寸Ｄ１＝１０６．３２＋０．０７　０ｍｍ,角度α＝１３°５０′;内滚道尺寸ｄ１＝８６．９３１　０－０．０５ｍｍ,角度β＝１０°２０′;滚子尺寸Δ＝１４．８　０－０．０２ｍｍ,滚子锥角φ＝１°４５′;挡边尺寸ａｏ＝４　０－０．０５ｍｍ;装配高Ｔ＝２６．５　０－０．５ｍｍ;其结构如图１所示。图１自１９９５年以来,加工３０２１４Ｘ２Ａ／ＨＡ轴承零件,合套检测时,常有３０～５０左右的零件装配高超差。为解决这一问题,进行以下分析。１　圆锥滚…     

产品之窗

·采用大型液晶显示和图标键·设置多种测量指令和创建反复操作程序、合格判定、统计演算等丰富功能·同类中唯一采用半浮上测定方式的产品性能参数：测量范围０～９２７（６００）ｍｍ分辨率０－０００１ｍｍ／０－００１ｍｍ／０－０１ｍｍ／０－１ｍｍ精度指示精度（２＋Ｌ／６００）μｍＬ＝任意测定长度（ｍｍ）反复精度平面０．５μｍ（２σ）孔１μｍ（２σ）直角度（前后）６μｍ（修正后）垂直度（前后）４μｍ（机械精度）测定力１Ｎ（自动定压功能）空气源内置压缩机”ＴＦＢＥ”快换式球型铣刀（专利产品）（ＳＵＰＥＲＢＡＬＬ…     

Z－0．036／7系列空压机的改进设计

Ｚ－０．０３６／７系列空压机的改进设计黄有祥福建压缩机总厂Ｚ－０．０３／７、Ｖ－０．０６／７系列空压机，配备电机功率分别为０．３７、０．７５ｋＷ，气缸直径５０ｍｍ，活塞行程３０ｍｍ。随着压缩机技术的发展以及用户对压缩机效率、能耗、噪声、运行安全可靠等...     

自动定心铣槽夹具的研制

自动定心铣槽夹具的研制沈阳冶金专科学校叶旭明，贾向义，曲贞江一、问题的提出在纺织器材中，有一种纺针，其结构如图１所示。从图中可知，纺针截面尺寸为０．５×３ｍｍ，需在０．５ｍｍ宽的纵向面上铣出一宽为０．２６ｍｍ的槽，该槽要求对称度允差０．０１ｍｍ．目前...     

齿轮设计中的理论误区

随着科学技术的发展,高精度齿轮在传动装置中得到了越来越广泛的应用。我公司作为一个以研制、生产大、中型、高精度、硬齿面齿轮装置为优势的企业,在承担的一项国家专项工程项目中,有９件齿轮精度均属３级,其中５件规格属大、中型,最大的一件齿轮顶圆直径为十Ｚ１７８ｍｍ,轴长２０８０ｍｍ,轴颈尺寸为邮７５（－０４８１／－０．５２０）。所有齿轮轴颈的形位公差均为３级,其圆柱度为（０．００３－０．００５）ｍｍ,全跳动为（０．００８－０．０１）ｍｍ。本文３级齿轮的研制生产在国内尚属首次,难度较大,但有我公司多年来生…     

偏心钉开口方法的改进

偏心钉是我厂量仪产品中的零件,如图１所示。加工时要在的小轴上加工０．３ｍｍ×７．５ｍｍ的槽口,按目前技术可用线切割、激光切割等方法。由于受设备所限,我厂一直用０．３ｍｍ的橡胶切断砂轮在工具磨上加工。在实际操作中存在下列问题不易解决：１．由于使用６．５外圆定位,偏心钉虽然夹在带Ｖ型槽的平口钳上,但所夹长度只有２．５ｍｍ,保证不了装夹的垂直度。２．由于两圆不同轴,所以圆的位置变动量大,切口时基本上是一件一校正。而且因０．３ｍｍ×１２５ｍｍ橡胶砂轮旋转时还有摆动,用目测法不易对准中心,当第一刀切偏后又…     

小尺寸刀具的真空化学热处理

小尺寸刀具的真空化学热处理目前涂层技术在小尺寸刀具（例如，直径０．０８～１，２ｍｍ的钻头、０．１～０．８ｍｍ厚的切槽铣刀及直径１．２～３．ｓｍｍ和长度５０～７０ｍｍ的加长旋转挫）上的应用很少，这与涂层装置的结构特点、加工成本和能耗高以及引起上述小刀具...     

薄壁套胶粘镶装工艺

薄壁套胶粘镶装工艺镶套件如图１所示，两动力头前后两轴承孔同轴度超差０．０６ｍｍ，且前轴承孔还存在０．０４～０．０５ｍｍ的椭圆度。由于前后两轴承孔同属薄壁套式座圈，若按传统工艺镶套（壁厚５ｍｍ）将造成箱体刚性严重下降，而电解镀覆技术又存在造价高、易剥离...     

家乐-5-5型多功能机在庆阳研制成功

由甘肃省庆阳地区汽车修配厂自行设计，制造的家乐－５－５型多功能机于１９９９年９月通过省级推广鉴定检测。该机具有体积小，重量轻，配套功能多，操作灵活方便之优点。适合于狭窄地段，山区梯田，果园，蔬菜大棚的耕作。可进行耕地、播种、施耕和除草等作业。该机主要技术性能有：配套动力：４－０５ｋＷ结构质量：１１０ｋｇ轮距：５２０ｍｍ理论速度：前进（两档）：９－６６．２ｋｍｈ倒退（两档）：６－４４．４ｋｍｈ作业速度：播种：４－３ｋｍｈ左右，耕地：２－５～３－０ｋｍｈ耗油量：耕地：０－０５Ｌｈｍ２，…     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.