Gear rack is a particular gear whose teeth are distributed about the strip.
1. The basic concept:
The rack can be split into a spur gear rack and a helical gear rack, which are paired with a spur gear and a helical gear, respectively; the tooth profile of the rack is usually a straight line rather than an involute (planar for the tooth surface) , equal to the indexing circle radius is definitely infinite cylindrical gear.
2. The main features:
(1) Since the tooth profile of the rack is right, each point about the tooth profile gets the same pressure angle and is add up to the inclination angle of the tooth profile. This angle is called the tooth position and the typical value is 20°.
(2) The same pitch and modulus are provided on the right lines parallel to the top line.
(3) A range parallel to the very best type of the tooth and having a tooth thickness add up to the width of the tooth groove is called a dividing line (middle line), which really is a reference line for calculating the size of the rack.
3. The main parameters:
Groove width, high tooth suggestion, high root height, tooth elevation, tooth thickness, root radius, etc.
4. The choice of parameters:
(1) Whether the gear is beating, the entire tooth depth, the normal normal range, the tooth direction is qualified, the tooth pitch is poor, and the circumferential section mistake has gone out of tolerance.
(2) Whether the installation distance following the gears and racks are installed is appropriate.
(3) The rack and gear meshing clearance should be 0.25* modulus.
(4) Whether the full tooth depth, runout, and common normal line of the rack are certified.
5. Processing methods:
Gear rack and pinion machining technique:
(1) hobbing
(2) gear shaping
(3) shaving
(4) grinding teeth
(5) molars