Encyclopedia Of Gear Classification And Parameter Calculation | PTJ Blog

# Encyclopedia Of Gear Classification And Parameter Calculation

2020-03-21

## Classification Of Gears

 Gears can be divided into three categories: cylindrical gears, bevel gears, worms and worm gears.

Classification of gears -PTJ CNC MACHINING Shop

## Types And Characteristics Of Cylindrical Gears

Cylindrical spur gears: the two axes of the large and small gears are parallel to each other; the line of the gear tooth length is parallel to the gear axis; when the external gear meshes, the two gears rotate in opposite directions; when the internal gear meshes, the two gears rotate in the same direction; The tooth profile can be made into normal teeth, short teeth, and can be displaced.

Cylindrical Helical Gear:The two axes of the large and small gears are parallel to each other; when the external gear drives, the two gears rotate in opposite directions; when the internal gear drives, the two gears rotate in the same direction; the tooth shape can be made into normal teeth, short teeth, and can be displaced; gears The tooth length direction line is inclined at an angle with the gear axis; the meshing transmission is smoother than the spur gear transmission, and the transmitted force is larger.

Helical gear: The two axes of the large and small gears can be parallel, staggered and perpendicular to each other in space; the rotation directions of the large and small gears can be the same or opposite; the angles of rotation of the large and small gears can be equal or different; When the rotation angle of the gear reaches a certain level, it becomes a taper.

Gears and racks: The gears that mesh with the racks can be spur gears or helical gears, and have the characteristics of spur gears or helical gears; rack and pinion transmissions change rotation into linear movement or change movement into rotation ; Racks are formed when the gear diameter is infinite

## Types And Characteristics Of Bevel Gears

Types And Characteristics Of Bevel Gears -PTJ CNC MACHINING Shop

Straight bevel gears: the two axes of the large and small gears intersect at the vertex of the bevel; when the large gear pitch cone angle is equal to 90 °, it becomes a flat production gear; when it is greater than 90 °, it becomes an internal meshing bevel gear.

Helical bevel gear: the tooth line is oblique, tangent to a circle, the tooth line does not intersect the cone top; the rotation angles of the large and small gears are equal, and the directions are opposite; the transmission is smoother than the straight bevel gear.

Spiral bevel gear: smooth transmission, large transmission force, suitable for off-speed transmission; large and small gears have the same rotation angle, opposite directions; the two gear axes intersect at the vertex of the bevel; arc bevel gear is divided into arc tooth, extension Cycloidal teeth, quasi involute teeth

## Types And Characteristics Of Worms And Worm Wheels

Types And Characteristics Of Worms And Worm Wheels -PTJ CNC MACHINING Shop

Archimedes worm: the tooth profile on the axial section of the worm is straight

Straight worm: the tooth profile on the tangent plane of the worm spiral line is straight

Involute worm: the tooth shape on the plane parallel to the worm axis and tangent to the base cylinder is linear

Arc worm and worm gear: efficiency is low, good oil film formation; large load capacity; complex manufacturing and assembly; also known as spherical worm gear pair; tooth shape is divided into: original type and modified plow.

The purpose of the correction is to make it easier for the worm gear to form an oil film in the transmission

## Gear Size Parameter Calculation Formula Chart

1.Calculation of internal gear modulus gear

2. Parameter calculation of spur gear

3. Parameter calculation of helical modular gear

4. Calculation of gear parameters

5. Calculation of spur pitch gear parameters

6. Parameter calculation of helical pitch gear

7. Calculation of rack parameters

## Gear Drive

The type of gear transmission is divided according to whether the axis position of each gear is fixed during transmission. The gear train is divided into two basic types: planetary gear train and fixed shaft gear train.

Fixed axis gear trains include flat fixed axis gear trains and space fixed axis gear trains. The geometric axis positions of all gears are fixed during transmission.

The planetary gear train can be divided into epicyclic gear train and differential gear train according to the degree of freedom. The epicyclic gear train has one degree of freedom, and the differential gear train has two degrees of freedom.

Reprint Statement: If there are no special instructions, all articles on this site are original. Please indicate the source for reprinting:https://www.cncmachiningptj.com/，thanks！

Our Services
Case Studies
Material List
Parts Gallery
﻿