HOW TO CHOOSE A TOOL FOR GEAR MACHINING?

Gear-cutting tools are tools used to machine the teeth of various cylindrical gears, bevel gears, and other toothed workpieces (see Gears). Gear cutters are divided into cylindrical gear cutters and beveled gear cutters according to the object to be treated. Bevel gear cutters are classified into 3 categories based on the type of gear being machined: straight bevel gear cutters, arc-tooth bevel gear cutters, and extended external bevel gear cutters. Cylindrical gear cutting tools can be divided into two types based on processing principles, namely, gear shaping tools and spread gear cutting tools.

Forming a gear cutter when the front angle is 0 °, the tooth shape of this type of cutter is the same as the groove shape in the end face of the cut straight tooth gear.

There are four main types of forming gear cutters.

① Disk gear milling cutter: used in a single piece, small batch, or repair production processing straight or helical cylindrical gears.

② Finger gear cutter: used for processing large modulus of straight, helical, and herringbone gears.

③ Gear broach: commonly used in mass production of internal gears.

④ Gear inserting cutter head: mainly used for machining straight-toothed external meshing cylindrical gears under mass production conditions. When processing helical gears with disk-shaped or finger-shaped gear cutters, the shape of the gear within the normal cross-section and the cutter tooth shape is slightly different from the shape of the tooth anywhere is not formed by a cutter tooth cut, it is cut by several cutter teeth of the cutter and enveloped by the cutter.

Gear Processing

Spreading gear cutting tool When a gear is machined with a spreading gear cutting tool, the gear to be machined and the cutter are rotated according to the desired transmission speed ratio, and the tooth shape of the gear is formed by successive envelopes of the tooth shapes of each neighboring cutter. These tools are commonly used as gear hobs, gear cutters, comb cutters, shaving cutters, etc. and are used to handle a variety of internal and external meshing straight and helical involute gears, non-involutional arc gears, cycloid gears, etc.

Spreading gear cutting tools have a wide range of applications in the processing of involute gears in the form of gear cutting tools. For example, the same tool can be used to process the module and pressure angle of the same involute gears with different numbers of teeth, can also be used in standard gear hob processing of different displacement coefficients of the dislocation of the gear. In addition, the machining accuracy and productivity of transmission gear tools are also higher, and therefore they are widely used in production.