Industry News

There are various forms of tooth profiles, among which the involute tooth profile is the most common. There are two major types of machining methods commonly used for involute tooth profiles, namely, the forming method and the generating method.

1. Gear milling

 Milling gear teeth using disc-shaped modular milling cutters or finger-type milling cutters belongs to the forming method of machining. The cross-sectional shape of the milling cutter teeth corresponds to the shape between gear teeth. This method has low machining efficiency and accuracy, and is only suitable for single-piece or small-batch production.

2. Form grinding

 It also belongs to the forming method of machining, but is rarely used due to the difficulty in dressing the grinding wheel.

3. Gear hobbing

 It belongs to the generating method of machining, and its working principle is equivalent to the meshing of a pair of helical gears. The prototype of a gear hob is a helical gear with a large helix angle. Due to the small number of teeth (usually tooth number z = 1), the teeth are very long, forming a worm with a small helix angle around the shaft. After being slotted and shaved, it becomes a hob with cutting edges and clearance angles.

4. Gear shaving

 In mass production, gear shaving is a commonly used finishing method for non-hardened tooth surfaces. Its working principle involves the free meshing motion between the shaving cutter and the gear being processed. By utilizing the relative sliding motion between the two, very fine chips are shaved off the tooth surface to enhance its precision. Gear shaving can also create drum-shaped teeth, which serve to improve the position of the tooth surface contact area.

5. Gear shaper

 Gear shaper is a commonly used gear cutting process utilizing the generating method, besides hobbing. During gear shaper, the gear shaper cutter and the workpiece are equivalent to the meshing of a pair of cylindrical gears. The reciprocating motion of the gear shaper cutter is the main motion of gear shaper, while the circular motion of the gear shaper cutter and the workpiece in a certain proportional relationship is the feed motion of gear shaper.

 This picture is not intuitive enough, but it's not a problem for our editor. The schematic diagram below should be clear to everyone at a glance.

6. Generating gear grinding

 The cutting motion of generating gear grinding is similar to hobbing, and it is a method of tooth profile finishing, especially for hardened gears, often being the only finishing method. Generating gear grinding can be performed using a worm wheel grinding wheel, or a conical grinding wheel or a disc grinding wheel.