外文翻譯----高速鉆床動(dòng)力學(xué)分析

1、附錄 附錄附錄 附錄 1： Kinematic and dynamic synthesis of a parallel kinematic high speeddrilling machineAbstractTypically, the term‘‘high speed drilling’’ is related to spindle capability of high cutting speeds. The suggested h

2、igh speed drilling machine (HSDM) extends this term to include very fast and accurate point-to-point motions. The new HSDM is composed of a planar parallel mechanism with two linear motors as the inputs. The paper is foc

3、used on the kinematic and dynamic synthesis of this parallel kinematic machine (PKM). The kinematic synthesis introduces a new methodology of input motion planning for ideal drilling operation and accurate point-to-point

4、 positioning. The dynamic synthesis aims at reducing the input power of the PKM using a spring element. Keywords: Parallel kinematic machine; High speed drilling; Kinematic and dynamic synthesis1. IntroductionDuring the

5、recent years, a large variety of PKMs were introduced by research institutes and by industries. Most, but not all, of these machines were based on the well-known Stewart platform [1] configuration. The advantages of thes

6、e parallel structures are high nominal load to weight ratio, good positional accuracy and a rigid structure [2]. The main disadvantages of Stewart type PKMs are the small workspace relative to the overall size of the mac

7、hine and relatively slow operation speed [3,4]. Workspace of a machine tool is defined as the volume where the tip of the tool can move and cut material. The design of a planar Stewart platform was mentioned in [5] as an

8、 affordable way of retrofitting non-CNC machines required for plastic moulds machining. The design of the PKM [5] allowed adjustable geometry that could have been optimally reconfigured for any prescribed path. Typically

9、, changing the length of one or more links in a controlled sequence does the adjustment of PKM geometry.The application of the PKMs with ‘‘constant-length links’’ for the design of machine tools is less common than the t

10、ype with ‘‘varying-length links’’. An excellent example of a ‘‘constant-length links’’ type of machine is shown in [6]. Renault-Automation Comau has built the machine named ‘‘Urane SX’’. The HSDM described herein utilize

11、s a parallel mechanism with constant-length links.Drilling operations are well introduced in the literature [7]. An extensive experimental study of highspeed drilling operations for the automotive industry is reported in

12、 [8]. Data was collected fromhundreds controlled drilling experiments in order to specify the parameters required for quality drilling. Ideal drilling motions and 2.1. Equations of motion of the PKM module with rigid lin

13、ksUsing complex-number representation of mechanisms [12], the kinematic equations of the tool unit (indicated as part 3 which includes the platform, the spindleand the tool) are developed as follows. The displacement of

14、the tool isandwhere b is the distance between point B and point C, r is the length of link AB (the lengths of link AB, CD and CE are equal). The velocity of the tool iswhereThe acceleration of the tool iswhereThe dynamic