Advanced Engineering Research (Dec 2016)
On design of worm gears with cylindrical worms
Abstract
The work objective is to introduce the visualization of the project main parameters into the design methodology to accelerate the adoption of constructive solutions while maintaining the geometric dimensions accuracy and their reference to the technical requirements. The task methodology provides the usability of programming, and the parameter analysis of worm gears that determine their performance. The calculation results are formed in arrays which serve as the basis for constructing two types of charts. For obtaining graphs of the functions of center distance from the transmitted torque, the most used formulas for the design calculation of worm gears on the contact endurance for the averaged values of the load ratios, gear ratios and the initial parameters of the gearing are used. The data are divided into three groups of materials with the appropriate allowable stresses, and into two kinds of worm profiles (line and not line). To gain the functionality of sliding velocities from the center distance, the velocities for lists of standard center distances and gear ratios are calculated. The results are a group of charts based on center distance up to 500 mm covering the entire standardized range from torques up to 20,000 Nm. The second group of graphs (dependences of sliding speeds from the center distance) is made for gear ratios up to 80, with rotational speed of worm 750, 1000 and 1500 rpm. The recommendations for selection by standard depending on the set rotation frequency of the worm are developed. The work performed allows concluding that graphs of the mutual dependence between parameters, geometry, loads, and kinematics of the worm gears create a range of rendering capabilities for a good scope of the main parameters selection. Depending on the application area, the graph parameters can be extended or stretched to the desired range without changing the principle of construction. The application of the described graphs allows a developer to reduce significantly the calculations cycle of slip speed and spacing under the contact endurance condition closed on the properties of the chosen transfer materials.
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