A rack is a special type of gear with teeth distributed on a strip. The gear rack is also divided into straight and helical gear racks, which are paired with straight and helical cylindrical gears for use respectively; The tooth profile of the rack is a straight line rather than an involute (which is a plane for the tooth surface), equivalent to a cylindrical gear with an infinite radius of the indexing circle.

Customized precision gear and rack machining

A rack is a type of strip component that matches a gear. It is equal to a segment of the circumference of a gear with an infinite diameter. On one side, there are many evenly distributed teeth that mesh with the gears, turning rotation into movement or turning movement into rotation.

(1) Due to the fact that the tooth profile of the rack is a straight line, each point on the tooth profile has the same pressure angle and is equal to the inclination angle of the tooth profile. This angle is called the tooth profile angle, with a standard value of 20 °. Currently, most positioning racks are helical teeth, with a tooth profile angle of 19 ° 31 ′ 42 ″.

(2) Any straight line parallel to the tooth crest line has the same tooth pitch and modulus.

(3) The straight line parallel to the tooth crest line and with a tooth thickness equal to the width of the tooth groove is called the indexing line (centerline), which is the reference line for calculating the size of the gear rack.

At present, automation equipment mainly consists of diagonal racks, which have characteristics such as high accuracy and high torque.