Development Of Belt Grinding Machine For Blades

Blade elements of complex surfaces are key components of aero engine, turbine and so on. The manufacturing quality of blade surfaces has a great influence on the performance of the machine. Due to poor processing properties of the materials, some of the blades on special occasions are very difficult to machine. At present, blade processing is as follows: first blank is close-tolerance cast or precision forged; second deburring is done by hand-held grinder; finally blade is polished used to hand-held fibre disc sander. The processing is able to avoid machining complex blade surface by CNC machine, but blade had to polishing on manual at last process.Burr-removing is the last working procedure of blade machining. The craftwork of burr-removing is lag in China, mostly on manual. It is low efficient, cost much, difficult to ensure precision and consistency.In order to substitute manual burr-removing, improve efficiency and the working environment for workers, a belt grinding machine for blades is designed to burr-removing. The belt grinding machine grinds blades by abrasive belt and has the following advantages: economy, high efficiency and strong adaptability. The application of free-form belt grinding makes the machine structure simplified. The pressure distribution on the Surfaces of blades is evenly at the contact points that improve the surfaces precision of blades. The belt grinding machine is able to improve the processing efficiency, precision and improve the environment of works. The following is details of this paper.The structure configuration of belt grinding machine is determined based on the requirement of burr-removing and the process of grinding the blades, then the overall structure of the belt grinding machine is designed. Air-operated special fixture and special center are designed based on the shape of blades. The belt grinding tool system is designed to meet the requirement of burr-removing. Three-dimensional solid model of the machine tool is verified by mechanical virtual assembly, interference checking and motion simulation. It is feasible in theory.The key parts of belt grinding machine are analyzed by static analysis to ensure that they are meet the strength and stiffness requirements in the course of processing.Simplified machine model is built to carry out modal analysis and harmonic analysis. The results show that operating frequency of the machine tool avoids machine's natural frequency and resonance does occur when the machine is running. Within the operating frequency of the machine, the bed fixed or not has little effect on amplitude and stress of the machine tool. It indicates that the machine can also carry out the grinding operation without fixing the bed. Rotating parts have a great effect on reliability and machining precision of the machine. Therefore, it is vitally necessary to ensure machining and assembly precision of the rotating parts by means of losing the eccentric mass of the rotating parts.Driving wheel and carrier of belt grinding tool system is shape or parameter optimized to reduce the mass of the parts improving the structure of the parts and the dynamic performance of the machine.