Research On Heavy Load Gear Modification

The field and the scope of the mechanical product application is more and morewidely, at the same time, people’s requirements for the product’s performance is alsohigher. As one of the most traditional driving part—gear is progress towards thedirection of High-speed overload and low-speed overload. So, the gear designer haspaid more and more attention to the transmission stability and bearing capacity of theoverload gear. Gear designer commonly take a appropriate profile modification andaxial modification for the gear to ensure a good transmission performance and a longservice life. According to profile modification and axial modification, this article didsome works as follows:At first, bearing stiffness of the Gear axle is obtained by Finite element iterationmethod. considering in the influence of the bearing stiffness and the elasticdeformation of the gear axle, gear mesh stiffness can be obtained by Ishikawa formula.And at the same time this paper deduced the equivalent tooth shape geometry size ofthe internal gear so that the Ishikawa formula can be used in internal meshing. On thatbasis, the elastic deformation at the moment when the gear engagement into themeshing is regard as the largest amount of the profile modification, and figure out theamount with the Ishikawa method thus the largest amount of the profile modificationunder the bearing stiffness and gear axle elastic deformation influence is worked out.in order to get the largest drum-shaped size, this paper considered both the contactdeformation on the tooth thickness direction and Meshing skewed degrees thatresulted by the gear axle and elastic deformation and the Space geometric factors. Onthe other side, get the drum center under the principle that get the best gear strengthand ensure the inter-mesh two teethes aren’t intercrosses but tangents.Based on the calculation method of the largest profile modification amount, thelargest drum-shaped size and the drum center, a gear modification calculate softwareis designed with VISUAL C++, modify the output gear of the pitch Reducer forMegawatt Wind Turbine by this software, then fixed the modification program of theoutput gear. Modeling the modified gear in SOLIDWORKS then input it intoABAQUS and ADAMS for CAE analysis，so, the stress distribution cloud, gearcontact area and revolving speed of the matching ring gear changes with the meshingtime can be compared between the modified and unmodified gears. After the CAE analysis, a test-bed is fixed for the contact figure test, the reliability of the modifiedgear is verified.