Description of the principle and characteristics of precision gear hobbing

Just follow what I shared before2Machining methods of large cylindrical gears, Now continue to share the description of the principle and characteristics of precision gear hobbing in Fancheng method. They are as follows for reference.

Precision gearThe gear hobbing has high precision and needs to be carried out on a gear hobbing machine. The following is the gear hobbing principle, hob and characteristics description:

XNUMX. Hobbing principle and hob:

Gear hobbing is based on the principle of forming-similar to the meshing of a worm and a worm gear to process gears.

The tool used is called a hob. The contour shape of the hob is similar to that of a worm. It is formed by the intersection of the spiral groove formed on the cylindrical surface of the tool and the groove cut perpendicular to the direction of the spiral groove to form a cutting edge. The cutting edge is similar To the tooth profile of the rack.

The rack can be correctly meshed with any gear with the same module and any number of teeth, so when hobbing a gear with the same module and any number of teeth, the required tooth profile can be obtained.

If the cutting edge is made from the rack, it is like a planer to make up and down reciprocating cutting motions. When the rack moves one pitch, the index circle of the tooth blank also rotates through the arc length of a circumferential pitch, and the cutting can be correct. The tooth shape comes.

However, when the rack is used as a cutter to cut gears, there is a contradiction between the number of teeth of the cut gear and the limited length of the rack.

The teeth of the rack cutter are regularly distributed on the spiral surface of the cylinder to obtain the shape of the hob.

5. Five characteristics of gear hobbing:

1. Continuous cutting, high productivity.

2. Compared with milling teeth, not only the tooth profile accuracy is high, but also the indexing accuracy is high.

3. Wide range of applications, not only can roll straight teethCylindrical gear, It can also roll helical cylindrical gears, worm gears, etc.

4. Generally, internal gears and multi-connected gears that are too close together cannot be processed.

5. Hobbing method can process cylindrical gears with the same modulus and different numbers of teeth with the hob of the same modulus.

The above is the relevant instructions for precision gear hobbing, including but not limited to, the gear shaping related content will be updated next time, so stay tuned!