The Optimization Design And Research Of Profile Of Pre-shaving Hob With The Capacity Of Ensuring Bigger Under Cutting Thickness

The current pre-shaving hob addendum lobe including flat type and round type. Gear cutter designers generally design it by serial design method. Due to not fully take into account the influence of gear tooth number, tooth thickness reduction, precision machining allowance and other factors, resulting in tool addendum lobe is too large and too long. When used for processing gears, it will make gear undercutting thickness too large and effective involute length too short, thereby affecting the gear meshing overlap coefficient and tooth carrying capacity.Or the effective involute length is enough, but gear undercutting thickness remains small after shaving. Under the precondition of satisfying the tooth root bending fatigue strength, properly increasing the gear undercutting thickness can effectively reduce the erosion to the gear pair caused by lubricating oil extrusion, and effectively reduce the oil temperature of the gear box. It has a good effect on reducing gear box energy consumption, noise and the gear loss. In addition, the applicabilityof current pre-shaving hob for modified gear and common normal process dimension in hobbing process is debatable. In the pre-shaving hob design process, there are many variables and complex operations. It will cost a lot of time if calucated by hand. The calculation accuracy and efficiency are low. It is not conducive to the practical application of engineering. So it's necessary to research and develop pre-shaving hob CAD system.This paper carried on research for the above problems and get the corresponding conclusion.(1) This paper analyzes the deficiencies of normal profile of current standard pre-shaving hob and the problems of design and calucation methods of normal profile dimensions, and elaborates the consequences of designing pre-shaving hob by serial design method.(2) we proposed that the design of pre-shaving hob should base on Concurrent Engineering Techniques. Improving the normal profile of pre-shaving hob by analyzing the influence factors of tool design and manufacturing, hobbing-shaving process and processing systems. And then get the new form of addendum lobe profile.(3)Establishing optimization design model of pre-shaving hob to match the tool addendum lobe profile dimensions reasonably.(4) Deriving the tooth profile curve parameter equation according to the tooth profile meshing theory, and then check the effective involute length based on Matlab mapping.(5) In order to reduce the workload of engineering and technical personnel, improve the design quality and design efficiency ofpre-shaving hob, and create practical value for engineering application,the pre-shaving hob accurate design CAD system with friendly man-machine interface is developed based on MATLAB GUI, which has the function of accurate operation and series design.