共查询到9条相似文献,搜索用时 0 毫秒
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风能是一种干净的可再生能源,利用风能进行发电不需要燃料、不会产生辐射或空气污染,具有广阔的发展前景。研究和推广小型风力发电机对于解决边远山区的生产、生活用电,推动生态环境建设等领域的发展将发挥积极作用。但是,目前市场上的小型风力发电机价格一般都较高,因此如何降低成本,研发实用型的小型风力发电机是科技人员急需解决的课题。本文主要针对家庭中的照明和一些小型电器的用电,设计出一种实用型的风力发电装置。 相似文献
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研究了一种新型的五自由度混联机械手,该机械手由一个三自由度并联机构和一个二自由度旋转头串接而成。在建立三自由度并联机构全雅可比矩阵的基础上,考察机构外力、外力矩对支链驱动力及约束力的映射关系,提出在给定载荷下,支链驱动力及约束力全域最大值均值最小的机构传动性能评价指标。给定机构期望工作空间,并以全局条件数、速度、精度为机构的操作性能指标,研究三自由度并联机构的尺度综合问题。通过单调性分析得到机构尺度参数对上述各指标的影响规律图谱,获得其优化设计区域,根据实际设计要求确定了参数变量。最后给出一组算例,验证了该尺度综合方法的有效性。 相似文献
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A New Tool-Path Generation Method Using a Cylindrical End Mill for 5-Axis Machining of a Spatial Cam with a Conical Meshing Element 总被引:2,自引:2,他引:0
R. S. Lee J. N. Lee 《The International Journal of Advanced Manufacturing Technology》2001,18(9):615-623
The geometry of a spatial cam is normally generated using a form-milling cutter and a special multi-axis machine and software.
The general purpose CAD/CAM software can generate the cutter location file of this class of product only by the sculpturing
method. Because of the limited choice of cutting tool when using the generating method, this paper presents a new toolpath
generating method which combines the advantages of the generating and sculpturing methods for machining a spatial cam. In
the machining process, the cutter location is derived for rough and finish machining using a cylindrical end mill. The guidelines
for choosing cutter diameter for the machining process are discussed. To avoid interference, the principal curvatures and
the principal induced normal curvatures are analysed. The mathematical errors including chordal deviation and scallop height
are used as the basis for generating appropriate tool-paths. Cutting simulation of a solid model was performed to verify the
proposed tool-path generation method. 相似文献
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A novel hybrid perfusion manipulator (HPM) with five degrees of freedom (DOFs) is introduced by combining the 5PUS-PRPU (P, R, U, and S represent prismatic, revolute, universal, and spherical joint, respectively) parallel mechanism with the 5PRR reconfigurable base to enhance the perfusion efficiency of the large-scale spherical honeycomb thermal protection layer. This study mainly presents the dimensional synthesis of the proposed HPM. First, the inverse kinematics, including the analytic expression of the rotation angles of the U joint in the PUS limb, is obtained, and mobility analysis is conducted based on screw theory. The Jacobian matrix of 5PUS-PRPU is also determined with screw theory and used for the establishment of the objective function. Second, a global and comprehensive objective function (GCOF) is proposed to represent the Jacobian matrix’s condition number. With the genetic algorithm, dimensional synthesis is conducted by minimizing GCOF subject to the given variable constraints. The values of the designed variables corresponding to different configurations of the reconfigurable base are then obtained. Lastly, the optimal structure parameters of the proposed 5-DOF HPM are determined. Results show that the HPM with the optimized parameters has an enlarged orientation workspace, and the maximum angle of the reconfigurable base is decreased, which is conducive to improving the overall stiffness of HPM. 相似文献