Recognizing Code: 

Such as double-gear 2610-2B is the outer 26 teeth, within 10 teeth, aperture 2mm tight fit 

A tight with small 0.05mm aperture than standard 
B said loose with than the standard aperture 0.05mm 

Calculate the gear diameter: 

(Number of teeth +2) * modulus = gear diameter 

Gear modulus of the package: 0.5 
Aperture: 1.5, 2, 2.5,3 

Modulus: 0.5 

Aperture 1.5, 2,2.5,3 

The mainshaft gears :8-1 .5 ??A 18-2.5A18-3A 82A 10-2A-2A 16-2A 9-2A 12-2A 

Crown teeth: C202.5A C24102Ac24102b C30102B 
C20-3A C28-2AC30-3A C3610-2B C2810-2A C20-2A 

The monolayer Gear: 202A 262A282A402A522.5A 563A24-2.5A 36-2A 38-2A 
38-3A 44-2A 44-2.5A 48-2A 46-2.5A 50-3A56-2A 422A 30-2A 

Double gear:18102A 48122.5A 4610-2B 4810-2B 2610-2B 2210-2B 
3212-2B 2810-2B 3808-2B 2810-2B 3210-2B2808-2B 
3412-2B 3610-2B 5010-2B 
4410-2B 5610-2A 3010-2B 2410-2B 

Worm: 6 * 6 (diameter 6mm * length 6mm), 6 * 8 (a diameter of 6mm, and a length of 8mm) 

Gear basic knowledge 

Tooth 
Referred to as teeth, the gear for engaging the convex portion, the convex portion is generally radially arranged paired gear tooth to contact each other, can constant engagement running gear; 

Alveolar 
The space between two adjacent teeth on the gear; face is a cylindrical gear or cylindrical worm, perpendicular to the plane of the axis of the gear or worm 

Normal plane 
Refers to a plane perpendicular to the tooth line 

Addendum circle 
Where the tooth top round 

Dedendum circle 
Refers to the bottom of the channel where the circle 

Base circle 
The formation of the occurrence of involute line for pure rolling circle 

Pitch circle 
Is calculated at the end face of the reference circle of the gear geometry. 

Each of the tooth (teeth) ─ ─ gear for engaging the raised portion. Generally, these convex portions are arranged radially. Paired gear tooth contact with each other, resulting in constant engagement operation of the gear. 

Alveolar the ─ ─ gear on the space between two adjacent teeth. 

Gear 
End face ─ ─ the cylindrical gear or cylindrical worm perpendicular to the plane of the axis of the gear or worm. 
Law face ─ ─ gear, the normal plane is perpendicular to the plane of the tooth line. 
Addendum circle ─ ─ teeth located at the top of the circle. 
Root circle ─ ─ circle where the bottom of the groove. 
Form involute base circle ─ ─ occurred lines on pure rolling circle. 
The pitch circle ─ ─ calculate the reference circle of the gear geometry to the face-to-face, in a the dividing circle on modulus and pressure angle spur gear are standard values. 
Tooth surface ─ ─ teeth of the side surface located between the cylindrical surface of the cylindrical surface of the addendum and the dedendum. 
Tooth profile ─ ─ tooth surface by a specified surfaces (cylindrical gear plane) cut cut line. 
Dentate line ─ ─ tooth surface with a dividing line of intersection of the cylindrical surface. 
The end face of the pitch pt ─ ─ two adjacent ipsilateral long end face sub-degree arc tooth profile. 
The modulus m ─ ─ pitch divided by pi π supplier, measured in millimeters. 
Diametral pitch p ─ ─ modulus of reciprocal, the inches. 
Tooth thickness s ---- in the end face of a tooth on both sides of the length of the sub-degree arc tooth profile. 
Slot width e ─ ─ alveolar in the end face of a sub-degree arc length between both sides of the tooth profile. 
Addendum hɑ ─ ─ radial distance between the tip circle of the pitch circle. 
Tooth root high Hf the ─ ─ indexing the radial distance between the circle and root circle. 
Total depth h ─ ─ addendum circle and dedendum circle between the radial distance. 
Tooth width b - tooth along the axial dimensions. 
Face pressure angle ɑt ─ ─ acute angle over-end round tooth profile and indexing the radial line through the point of intersection of the tangent of the folder tooth profile. 

Standard Rack: only the size of the base circle, tooth, the whole tooth height, crown height and tooth thickness dimensions are in line with the standard specifications of the rack gear, cutting out the rack according to their standard gear specifications called benchmark rack. 
The reference pitch circle (Standard Pitch Circle): used to determine the various dimensions of the reference circle of the gear. Modulus is the number of teeth x 

Standard Pitch Line: rack on a particular section of line or tooth thickness measured along this line, half of the pitch.

Action Pitch Circle: occlusal role of a spur gear, each with a tangent rolling circle. 

Standard Pitch: benchmark, with the benchmark rack pitch equal to the selected standard pitch. 

Pitch Circle: two gears with heart online occlusal contact points of each gear, left the track called the pitch circle. 

Pitch Diameter: pitch circle diameter. 

Working Depth: a spur gear tooth crown height., Also known as tooth height. 

Addendum: the addendum circle of the pitch circle radius.

Backlash: two teeth bite, the tooth surface and tooth surface gap. 

Clearance: two teeth bite, the gap between a gear addendum circle with another gear bottom. 

Pitch Point: a pair of gears with pitch circle tangent point. 

itch: two adjacent interdental corresponding point arc distance. 

Normal Pitch: involute gear along a particular cross section measured by the same vertical pitch.