Gear rack is a particular gear whose teeth are distributed on the strip.
1. The basic concept:
The rack is also divided into a spur gear rack and a helical gear rack, which are paired with a spur gear and a helical gear, respectively; the tooth account of the rack is normally a straight line instead of an involute (planar for the tooth surface) , equal to the indexing circle radius is usually infinite cylindrical gear.
2. The main features:
(1) Because the tooth profile of the rack is right, each point on the tooth profile gets the same pressure position and is equal to the inclination position of the tooth profile. This angle is named the tooth angle and the standard value is 20°.
(2) The same rack and pinionpitch and modulus are given on the direct lines parallel to the top line.
(3) A series parallel to the top line of the tooth and having a tooth thickness add up to the width of the tooth groove is named a dividing series (middle line), which really is a reference range for calculating the size of the rack.
3. The main parameters:
Groove width, high tooth suggestion, high root elevation, 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 collection, the tooth direction is qualified, the tooth pitch is poor, and the circumferential section error is out of tolerance.
(2) If the installation distance after 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 type of the rack are skilled.
5. Processing methods:
Gear rack and pinion machining method:
(1) hobbing
(2) gear shaping
(3) shaving
(4) grinding teeth
(5) molars