Casting,Forming,andForging-ASMInternational.PDFVIP

© 2005 ASM International. All Rights Reserved. Gear Materials, Properties, and Manufacture (#05125G) CHAPTER 6 Casting, Forming, and Forging GEAR MANUFACTURE depends on ma- For example, cast tooth internal gears (Fig. 3) chinery available, design specifications or are produced in several sizes up to 1633 kg requirements, cost of production, and type of (3600 lb). They are heat treated to strength lev- material from which the gear is to be made. els of 689 MPa (100 ksi) and machining is not There are many methods for manufacturing required on these gears. In circumstances where gears including: machining is necessary, the machining expense is reduced by casting close to final shape. • Metal removal processes (hobbing, shaping, Another example of a cast tooth gear is the milling, shaving, grinding, honing, and lap- pinion gear produced from cast high-manganese ping) as discussed in Chapter 5 (Hadfield) steel for an electric mining shovel • Various casting processes for both produc- shown in Fig. 4. It was not necessary to machine tion of gear blanks and near-net shape gears the gear teeth. • Stamping and fine blanking Specific Casting Processes. Most casting • Cold drawing and extrusion