Dissertation > Excellent graduate degree dissertation topics show

Study on Novel Gantry Hybrid Grinding and Polishing Machine Tool for Blade Finishing

Author: LiRuiQing
Tutor: ZhaoJi
School: Jilin University
Course: Mechanical Manufacturing and Automation
Keywords: Hybrid Machine Tool Blade grinding and polishing 3 - RPS parallel mechanism Finite Element Analysis Modal
CLC: TG580.6
Type: Master's thesis
Year: 2011
Downloads: 90
Quote: 0
Read: Download Dissertation

Abstract

With the extensive application of the turbine, turbine and aero engine axial turbomachinery, leaves as one of the important parts, leaf quality directly affects the performance of the steam turbine, turbine and aircraft engine. Blades with the complexity of the design process, by the space complex surface, poor working conditions, high accuracy requirements. Blade design, materials, mechanical processing, heat treatment and surface spray process demanding any minor defects in the design and manufacture will affect the work efficiency, or even the entire unit damage. With mature and widely used commercial CAD software, blade design capability has been greatly improved. However, in the manufacturing process, the low degree of automation of the finishing process of grinding and polishing, requires a lot of manual to achieve the blade surface accuracy and surface quality requirements, not only takes a lot of labor, and the quality is often guaranteed by the experience of processors. To raise the blade surface grinding and polishing finishing degree of automation, improve the efficiency of blade development, shorter blade design production cycle, to reduce the impact of human factors on the blade accuracy and surface quality, the research group has developed a new hybrid grinding and polishing machine, and application blade grinding and polishing work fully combines the advantages of parallel institutions and traditional tandem machine, not only can take full advantage of the parallel mechanism of high rigidity, high-precision, high flexibility and flexible features, and two mobile series beams and bed free degrees, effectively solve the problem of parallel kinematic space and reasonable distribution of sports stroke, to adapt to the characteristics of the blades workpiece. Through grinding and polishing tool along the Z axis of the X axis linear motion and the motion platform 3-RPS move around the X-axis of rotation and is rotated around the Y axis with three degrees of freedom of movement, to drive the blade movement to form a composite motion, bag Le blades Four DOF section line, then through the feed motion of the series of the bed along the Y axis, may be capable of processing to the entire surface of the blade. -Hybrid blade grinding and polishing machine research group first proposed, and applied for two patents, one invention patent CN101148021 another for utility model patents CN201109062. Key projects funded under the Science and Technology Development Plan of Jilin Province, conducted a study of new mixed-linked-blade grinding and polishing machines, including the required degree of freedom machine, degrees of freedom allocation, the configuration of the transmission chain, core components and machine overall structural design is now The completed machine design and development work and machining assembly into the machine commissioning phase. Establishes a 3-RPS parallel mechanism independent degrees of freedom, and the 3-RPS parallel mechanism kinematics and dynamics analysis to establish the model of the the parallel mechanism independent degrees of freedom between the driver, deputy position, velocity, acceleration, and other positive and negative solution Lagrangian method to establish a dynamic model of the parallel mechanism; structural design combined with 3-RPS parallel mechanism and kinematic analysis, solving a different position and attitude angle space. According to the the blade structural features, the machine tool the machine motion planning and trajectory planning motion assigned to the machine each active degree of freedom, blade grinding and polishing machine hybrid simulation analysis. Simulation process, the changes due to the curvature of the blade at the edge of a larger machine tools, grinding and polishing processing be an impact. In order to reduce the impact, the interpolation processing of the machining point of the blade at the edge, increasing the data points at the edge of the blade, reducing the movement step. The smooth interpolation processing, the simulation process of grinding and polishing of the entire blade spiral, produce no significant impact. At the same time, the simulation analysis also shows that the servo motor power requirements fully meet the the blades grinding and polishing process. Local machine details and the combination of surface treatment, the establishment of a finite element model of the 3-RPS parallel mechanism and machine tool, and the use of finite element analysis software ANSYS analysis machine static and dynamic performance. Machine static performance better ,3-RPS parallel mechanism and machine tool stiffness; complete machine tool modal analysis using finite element and experimental method, the natural frequency of the machine are two ways to get close to. The completed machine X, the experimental study of the precision of the Y-axis of motion detection experiments and blade grinding and polishing single factor. Detection experiments of precision machine tools, machine tool X, Y movement axis positioning accuracy and repeatability of positioning accuracy and straightness detection. Blade grinding and polishing abrasive belt size, belt speed and feed rate of single factor experiments, the experimental results show that the abrasive belt size blade grinding and polishing effect the greatest impact, the greater the higher the speed abrasive belt abrasive belt granularity the grinding and the feed speed is lower, the better, and allows the blade to achieve a lower surface roughness.

Related Dissertations

CLC: > Industrial Technology > Metallurgy and Metal Craft > Metal cutting and machine tools > Grinding and grinding machine > General issues > Grinding process
© 2012 www.DissertationTopic.Net Mobile