4.1.1 Developments in Productivity
Huge increases in productivity have been achieved in recent decades due to advances in grinding wheel technology. These increases have only been possible by parallel developments in the machines and auxiliary equipment employed since the greatest gains have been from the grinding system.
Grinding wheels operating at low wheel speeds employed in the early twentieth century have progressed to advanced conventional abrasives and superabrasives operating at high wheel speeds in the present era. Over this period, material removal rates have increased for some grinding processes by a staggering 10 to 100 times. The grinding wheel technology that made such advances possible primarily involved the development of new abrasives as described in Chapter 5. In this chapter, mechanical design aspects of wheel design are introduced that affect grinding quality, performance, and safety. Essential information is given on wheel design for high-speed operation including design of segmented wheels.
4.1.2 System Development
New abrasives require new ways of working that reflect in new designs of grinding wheel assembly, truing, dressing, and conditioning techniques, coolant delivery and coolant formulation, and finally, new designs of machines capable of high wheel speeds and capable of delivering higher power to the grinding wheel. A variety of wheel designs have developed to cope with differing product geometries.
However, two other considerations gave rise to a new approach to wheel design:
• High wheel speeds must be designed for much greater wheel strength.
• Expensive, but hard-wearing, diamond and cubic boron nitride (CBN) superabrasives only need thin layers of abrasive to achieve a long wheel life.