What are the characteristics of gear hobbing, gear shaping, and gear shaving?

Writer： admin Time：2024-03-12 15:26:13 Browse：42℃

Features of gear hobbing:

1. High productivity.

2. The tooth profile accuracy of hobbing is lower than that of slotting, and the number of tangent lines forming the tooth profile envelope is only related to the number of chip grooves in the hob and the number of basic worm heads. It cannot be increased or decreased by changing the processing conditions.

3. When machining worm gears, only gear hobbing can be used.

Features of gear shaping processing:

1. When cutting gears with a larger modulus, the gear shaping speed is constrained by the inertia of the reciprocating motion of the gear shaping cutter spindle and the rigidity of the machine tool; The cutting process also incurs time loss due to idle travel, so the productivity is not as high as that of gear hobbing. Only when machining gears with small modulus, multiple teeth, and narrow tooth width, can the productivity of gear hobbing be higher than that of hobbing.

2. The number of tangent lines that form the tooth profile envelope is determined by the magnitude of the circumferential feed rate and can be selected. When inserting gears, the cutting of the gear cutter along the tooth direction is continuous, and the tooth surface roughness is relatively fine.

3. The tooth alignment error during gear shaping mainly depends on the parallelism error between the spindle rotation axis of the gear shaping machine and the worktable rotation axis. Due to the high frequency of reciprocating motion during the operation of the gear cutter, there is significant wear between the spindle and the sleeve, resulting in a relatively large tooth orientation error of the gear cutter.

4. When machining gears with shoulder and double or multiple gears with narrow empty tool slots, only gear hobbing can be used.

Shaving processing characteristics:

1. The machining accuracy of gear shaving is generally 6-7 levels, and the surface roughness Ra is 0.8-0.4 μ m. Used for precision machining of unhardened gears.

2. The productivity of gear shaving is high, and it usually only takes 2-4 minutes to process a medium-sized gear. Compared with gear grinding, it can increase the productivity by more than 10 times.

3. Due to the fact that gear shaving is a free meshing process, the machine tool does not have a developed motion transmission chain, resulting in a simple structure and easy adjustment of the machine tool.