MODELING OF HEAT TRANSFER IN WORM GEARS

Sobolev Aleksandr Nikolaevich, Candidate of engineering sciences, associate professor, sub-department of machine tools, Moscow State Technological University "Stankin" (3a Vadkovskiy lane, Moscow, Russia), t-64@mail.ru
Kosov Mikhail Georgievich, Doctor of engineering sciences, professor, head of sub-department of basic machine construction, Moscow State Technological University “Stankin” (3a Vadkovskiy lane, Moscow, Russia), t-64@mail.ru 

62-233.3/.9:004.9 

Background. With improved methods of design and production technology worm gears have great potential of use in various machines instead of cylindrical gears. An important problem in the design of worm gears is the solution of thermal problems. The article analyzes the problems of calculation and modeling of temperature fields in the worm gears, including the use of computer-aided design.
Materials and methods. Solution of the problem of thermal design of worm gears can be carried on the basis of analytical methods or based on the finite element method (FEM).
Results. To solve the problems of heat transfer the authors developed computational models of two parametric designs of worm gear units with horizontal and vertical location of the worm. On the basis of numerical algorithms the surface area of the gear case can be accurately determined, including the area of the working chamber of the body, thereby improving the accuracy of calculations. The results of numerical simulations have shown that the air cooling fan improves heat dissipation when the fan is mounted on the shaft of the worm aas well as on the worm gear.
Conclusions. To improve the heat dissipation in worm gears it is possible to use special fans. The usage of finite element modeling eliminates the full-scale experiments with the manufacture of prototypes. Heat dissipation developed for the gear hull is better by 20 % (based on the simulation results) compared with the results of conventional calculations. A further way to improve the results of numerical simulation is to solve some problems of contact with the friction forces, in particular in the contact area of the worm wheel and the bearing assemblies.

worm gear, numerical modeling, gears, heat transfer. 

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