Papers by Author: Ru Sheng Lu

Abstract: Based on features of any shape of wire with complex geometric patterns, a method for modelling 3D wire is proposed, and the machining simulation of the 3D wire and collision detection between the wire and the machine are introduced. By using double buffering technology, we obtain smooth animation during the off-line machining simulation. The computational cost of a collision detection algorithm is decided not only by the complexity of the basic interference test used, but also by the number of times every test is applied. To simplify the collision detection algorithm, an approximate method of representing wire model and machine model by using line segments and planes is applied.

Abstract: In order to describe the forming grinding principle of screw rotor, the mathematical model of screw rotor’s helical groove and forming grinding wheel are established by differential geometry theory and numerical analysis method. And the contact line equation is derived. To optimize the traditional method of calculating forming grinding wheel by known rotor end section profile, a numerical analysis method (Accumulated Chord Length Parameter Method) has been presented in detail. This method can improve the efficiency and reliability of the calculation of forming grinding wheel axial profile. Taking the asymmetry linear screw rotor (female) as an example, this paper calculates the grinding wheel axial profile and draws it using special designed software. The simulation examples are done by CAD (Computer Aided Design) based on the secondary development technology of UG. This study provides a precise 3D model which can be used in areas such as finite element analysis and virtual testing experiments.

Abstract: Upon studying the form grinding principle of helical groove and the conjugate movement between the grinding wheel and screw rotor, the equation of their contact line is firstly derived. The problem of smoothing the profile of grinding wheel is then solved by using the point selection smoothing method which is concludes from the theory of complex curves and numerical analysis. Finally, with the help of computer, the simulation processing is done with the final result shows that this design method is reliable. It can not only reduce the time for design and the number of trial samples but also provides a 3D model which can be used in virtual test of screw rotor.

Abstract: On the basis of analyzing the geometric characteristics of the helical groove, the interfer -ometry method for its processing is discussed. This paper establishes a mathematical model of the helical groove, using differential geometry theory and numerical analysis. This research analyzes the impact of machine adjustment parameters (i.e. setting angle) on the geometry specification (i.e. Rake angle) of the helical groove. The simulation examples are done by CAD (Computer Aided Design), and the reasonable adjustment of machine parameters will be obtained by computer simulation and statistical analysis. This will reduce the time for design, the number of trial samples, and production costs. This study provides a precise 3D helical cutter model which can be used in areas such as finite element analysis (FEA) and virtual cutting tests.