When milling a helical cylindrical rack, the tool number should be selected according to the number of equivalent teeth, so do you know what is the equivalent number of teeth of a helical cylindrical rack? The small circle gear below the gear shaft will introduce it to you.

gearbox gear shaft

According to the geometric relationship, the intersection of the normal plane at a certain point on the tooth line of the helical spur gear and the indexing cylindrical surface is an ellipse. The maximum curvature radius of this ellipse is used as the indexing circle radius of an imaginary spur gear, and the normal module and normal tooth profile angle of this helical gear are used as the module and tooth shape of the imaginary spur gear. angle, the imaginary spur gear is called the equivalent gear of the helical spur gear. The so-called equivalent number of teeth of the helical cylindrical gear refers to the equivalent number of teeth of the helical cylindrical gear.