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Classification of gears

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Time:2024-01-12 15:43


Gears are generally divided into three categories

There are a wide variety of gears, and their classification is usually based on the gear shaft. It is generally divided into three types: parallel axis, intersecting axis and staggered axis.

1) Parallel shaft gears: including spur gears, helical gears, internal gears, racks and helical racks.

2) Intersecting shaft gears: straight bevel gears, spiral bevel gears, zero-degree bevel gears, etc.

3) staggered shaft gear: staggered shaft helical gear, worm and worm gear, hypoid gear, etc.

3.1 parallel shaft gear

1) Spur gear

Cylindrical gears whose tooth line is parallel to the axis line. Because it is easy to process, it is widely used in power transmission.

2) Rack

A linear rack gear that meshes with a spur gear. It can be regarded as a special case when the pitch diameter of the spur gear becomes infinite.

3) Internal gear

A gear that meshes with a spur gear and is machined with gear teeth on the inner side of the ring. Mainly used in planetary gear transmission mechanism and gear coupling and other applications.

4) Helical gear

Cylindrical gears with helical lines. Because of its higher strength and smooth operation than spur gears, it is widely used. Axial thrust is generated during transmission.

5) Helical rack

A strip gear that meshes with a helical gear. This corresponds to the case when the pitch diameter of the helical gear becomes infinite.

6) Herrer gear

The tooth line is a gear composed of two helical gears with left and right hand. There is an advantage that no thrust is generated in the axial direction.

3.2 intersecting shaft gear

1) Straight bevel gear

Bevel gears whose tooth lines are consistent with the generatrix of the pitch cone line. Among bevel gears, it is of the type that is relatively easy to manufacture. Therefore, as a transmission with a wide range of bevel gears.

2) Spiral bevel gear

Bevel gears with a curved line with a helix angle. Although it is more difficult to manufacture than a straight bevel gear, it is also widely used as a gear with high strength and low noise.

3) Zero degree bevel gear

Curved bevel gears with a helix angle of zero degrees. Because of the characteristics of both straight and curved bevel gears, the force on the tooth surface is the same as that of straight bevel gears.

3.3 staggered shaft gear

1) Cylindrical worm gear pair

Cylindrical worm pair is a general term for cylindrical worm and worm wheel meshing with it. The quiet operation and the large transmission ratio that can be obtained in a single pair are its remarkable features, but the disadvantage of low efficiency.

2) staggered shaft helical gear

The name of the cylindrical worm gear pair when driving between staggered shafts. It can be used in the case of helical gear pairs or helical gear and spur gear pairs. Although the operation is smooth, it is only suitable for use under light load conditions.

3.4 other special gears

1) Face gear

A disc-shaped gear that can mesh with a spur gear or a helical gear. Transmission between orthogonal and staggered shafts.

2) Drum worm gear pair

The general term for the drum-shaped worm and the worm gear that meshes with it. Although it is difficult to manufacture, it can transmit large loads compared with cylindrical worm pairs.

3) Hypoid gear

Conical gears that drive between staggered shafts. The large and small gears are processed eccentrically, which is similar to the arc gear, and the meshing principle is very complicated.