共查询到17条相似文献,搜索用时 171 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
目前国内的履带式作业机如东方红履带拖拉机、各种履带式推土机等大部分采用转向离合器作为转向机构.行星转向机构的应用仅见于前苏联履带式拖拉机,该驱动桥具有零件数目少、零件耐磨性高、故障少、对传动系实现一定速比的降速等优点,有不少可取之处,文中针对前苏联ДТ-75 МЛ履带拖拉机对履带驱动桥行星转向机构的工作原理进行了理论分析,为国内行星转向机构履带驱动桥的开发提供一些技术参考. 相似文献
11.
在介绍了采用CATIA软件对割缝筛管进行参数化建模和应力分析方法的基础上,结合实际完成了某割缝筛管的建模与有限元分析,并将分析结果与国外实验数据作了比较。结果表明,采用CATIA软件作为建模和有限元分析工具,将割缝筛管的三维建模与有限元分析两项工作在一个系统中完成,可以避免接口传递可能产生的数据误差,提高了割缝筛管设计与分析的质量和效率。 相似文献
12.
鉴于目前对客车安全性、舒适性、行驶平稳性等综合性能要求的日益提高,从分析客车结构动态性能出发,针对分析过程中有限元模型建立这一最关键阶段,在现有客车有限元建模技术的基础上,讨论了建立客车整车有限元模型的方法。由几何模型转化成有限元模型,并对部件问的连接进行有效模拟,完成整车有限元模型的建立,为进行动态结构分析奠定了基础。 相似文献
13.
14.
15.
Based on electromagnetic flux leakage (EMFL), a nondestructive testing (NDT) technique for the detection of gas pipe wall thickness is presented, and its principle and feasibility is evaluated by means of equivalent magnetic circuit analysis and finite element analysis. An online NDT device adopting this technique is developed, and its structure and working principle are introduced in detail. This device is composed of a detector array with 32 pipe wall thickness sensors that employ a Hall element as the element for sensing the magnetic flux density, and it can be adapted to pipe diameters from Ø400mm to Ø650 mm. On the basis of the experimental investigation for this device, the influences of some factors on thickness measurement, namely the excitation current, excitation coil turns, gap distance, concentrator of the magnetic field, magnetization time, and number of sensors in the detector array, are revealed and the optimal excitation voltage for the sensors of the detector array is selected. The measuring calibration is given to establish the relationship between the pipe wall thickness and the output voltage of the sensors. The results show that the proposed EMFL for measuring the wall thickness of ferromagnetic pipe is feasible, the technical parameters of the sensor are important for improvement of measurement precision and resolution, and the developed device has precision, resolution, and a linear output curve. Carried by the developed gas pipeline inspection robot through a universal joint, this NDT device can move inside the gas pipeline and monitor the state of the pipe wall. 相似文献
16.
17.
A. Noorul Haq T. Tamizharasan 《The International Journal of Advanced Manufacturing Technology》2006,30(9-10):808-816
As a means to overcome the limitations of cutting fluids in machining, more and more attention is being paid to the internal cooling of cutting tools. The elevated cutting zone temperature in hard turning causes the instant boiling of coolant in the cutting zone, which pulls down the tool life and surface finish, by making thermal distortions and hence in most of the hard turning operations, the coolant is not used at all. The absence of coolant also reduces the tool life and surface finish to some extent. As an alternative solution to the direct application of coolant in the metal cutting zone to improve tool life and surface finish, the heat pipe cooling system is introduced in this investigation. A parametric study is conducted to analyze the effects of different heat pipe parameters such as diameter of heat pipe, length of heat pipe, magnitude of vacuum in the heat pipe and material of heat pipe. All these parameters are varied to three levels. In this analysis, it is assumed that the single point cutting tool is subjected to static heating in the cutting zone which verifies the analysis and feasibility of using heat pipe cooling in turning operations. The heat pipe parameters are optimized by using Taguchi’s Design of Experiments and a confirmation test is conducted by employing the heat pipe fabricated with the best values of parameters. The results of the confirmation test are compared with the previous experimental results. The comparison shows that the use of a heat pipe in hard turning operations reduces the temperature field by about 5%, improves tool life by reducing tool wear and improves surface finish significantly. The result of this analysis is applicable to define controlling parameters of heat pipes for optimal design and set-up for various related studies. The finite element analysis also shows that the temperature drops greatly at the cutting zone and that the heat flow to the tool is effectively removed when a heat pipe is incorporated. 相似文献