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

1, high productivity.

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

3, processing worm gear, can only use hobbing.

Machining characteristics of gear shaper;

1. When cutting large module gears, the gear shaping speed is restricted by the reciprocating inertia of the gear shaper cutter spindle and the rigidity of the machine tool; The cutting process also has time loss, so the productivity is not as high as hobbing. Only when machining gears with small modulus, many teeth and narrow tooth width, the productivity of gear shaping is higher than that of hobbing.

2. The number of tangents forming the tooth envelope is determined by the circumferential feed and can be selected. The gear shaper cutter cuts continuously along the tooth direction during gear shaping, and the tooth surface roughness is fine during gear shaping.

3. The tooth orientation error in the process of gear shaping is mainly determined by the parallelism error between the spindle axis of the gear shaper and the axis of the workbench. Because the frequency of reciprocating motion of gear shaper cutter is high and the wear between spindle and sleeve is large, the tooth direction error of gear shaper cutter is large.

4. When machining gears with shoulders and double gears or multiple gears with narrow empty cutter slots, only gear shapers can be used.

Characteristics of shaving:

1, the shaving accuRacy is generally 6 ~ 7, and the surface roughness ra is 0.8 ~ 0.4 micron, which is used for finishing non-quenched gears.

2. High shaving productivity. Generally, it only takes 2 ~ 4 minutes to process a medium-sized gear. Compared with gear grinding, the productivity can be increased by more than 10 times.

3. Because the shaving process is free meshing, the machine tool has no generating motion transmission chain, the machine tool structure is simple, and the machine tool is easy to adjust.

Extended data

Gear hobbing machines are widely used in automobile, tractor, machine tool, construction machinery, mining machinery, metallurgical machinery, petroleum, instrumentation, aircraft and spacecraft and other machinery manufacturing industries.

Gear machining machine tool is a toothed machine tool for machining all kinds of toothed parts such as cylindrical gears and bevel gears. There are many kinds of gear processing machine tools, including small machine tools for processing gears with a diameter of several millimeters, large machine tools for processing gears with a diameter of more than ten meters, and a large number of high-precision machine tools for processing precision gears with efficient machine tools.

In ancient times, gears were formed by hand filing. 1540, when making clocks and watches in toliano, Italy, a tooth cutting device using a rotary file was made; 1783, René, France, manufactured a gear processing machine tool using a milling cutter, with accessories for cutting gears in the rack. About 1820, White of England made the first machine tool that can process both cylindrical gears and bevel gears.

Machine tools with this performance developed again in the second half of the19th century.

1835, Whitworth, England obtained the patent of worm gear hobbing machine; 1858, Schiller obtained the patent of cylindrical gear hobbing machine; After many improvements, it was not until 1897 that the hobbing machine with differential mechanism was manufactured in Puffarth, Germany, that the machining problem of helical gears was successfully solved. After the gear shaper cutter was made, Fellows of America made the gear shaper cutter in 1897.

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