Study on Minimum Teeth without Undercutting of Involute Gears with 14.5 Degree Pressure Angle

Abstract

Study on minimum teeth without undercutting for considering the rack cutter’s addendum c*m of a kind of gear with 14.5 degree pressure angle, and the gear standard No is B436-1940 and used in UK. Based on the generating method, reasons for undercut phenomena is analyzed, and the numbers of minimum teeth without undercutting of the involute spur gear, involute helical cylindrical gear and involute spur bevel gear are theoretically analyzed and figured out. The correct number of minimum teeth without undercutting of gear with 14.5 degree pressure angle is given, and also illustrated the validity of theoretical derivation.

New Insights Into the Minimum Teeth Number and Modification Coefficient of Standard Involute Gears Without Undercutting

“…During the study of the minimum number of teeth of standard involute gear teeth without undercutting, the concept of 'rack cutter has been mistakenly regarded as rack in the study of the minimum number of teeth without undercutting in many textbooks' is promoted for the first time [32] by the researchers. In the studies of involute spur gear undercutting with different pressure angles based on the VB programme and the neural network method, undercutting of involute gear with different pressure angles, namely, 14.5°, 22.5°, and 25°, are discussed [33][34][35][36][37]. Researchers from all over the world are dedicated to the gear design and manufacturing research and a significant amount of important findings have been acquired.…”

“…In traditional theories, undercutting occurs when the rack addendum goes beyond the mesh limit point, but the actual gear machining process is ignored. In practice, the c (the height fillet portion, c= c * m) must be added on the cutter top to generate the radial clearance portion [36]. Therefore, in the actual manufacturing process of involute gears, the limit meshing point is not the intersection point of the meshing line and the addendum line of the cutter, but the crossover point of the meshing line and the top line of the fillet portion of the rack-shaped cutter, as shown in Fig.…”

Simulation and Analysis about Different Pressure Angle in Involute Gears Based on Neural Network

“…Yet, due to the largest part of undercutting is in rolling circle and there is non involute in the base circle. So in theory, the undercutting value calculation is quite troublesome [1][2].…”