Nevertheless, the design still has problems with bore expansion albeit now directed to a movement on a keyed tapered arbor. For the very highest wheel speeds, OEMs and wheel makers are designing 1-pc integral hub, plain body 1-pc integral hub, turbine body profile wheels to bolt directly to the motor spindle. Several examples for both […]
Рубрика: Handbook of Machining with Grinding Wheels
Origin of Diamond
Diamond is created by the application of extreme high temperatures and pressures to graphite. Such conditions occur naturally at depths of 120 miles in the upper mantle or in heavy meteorite impacts. Diamond is mined from Kimberlite pipes that are the remnant of small volcanic fissures typically 2 to 50 m in diameter where magma […]
GRAIN SIZE DISTRIBUTIONS
Several national and international standards define particle size distributions of abrasive grains. All are based on sizing by sieving in the sizes typical of most regular grinding applications. 5.8.1 The ANSI Standard In the case of the ANSI standard [B74.16 1995], mesh size is defined by a pair of numbers that corresponds to sieves with […]
PHENOLIC RESIN BONDS
6.10.1 Introduction Phenolic bonds represent the largest market segment for conventional grinding wheels after vitrified bonds, and dominate the rough-grinding sector of the industry for snagging and cutoff applications. The bonds consist of thermosetting resins and plasticizers, which are cured around 150 to 200°C. The bond type was originally known as “Bakelite” and for this […]
Dressing Conditions for Disc Dressers
Traverse rates should be calculated from actual geometry of the disc. For discs of a given tip radius, r, and depth of dress, ad, simple geometry gives the effective contact width as bd = 2[(2r — ad)ad]J. The same rules for overlap factor, Ud, as a function of bd apply as for stationary tools. Dress […]
Four Basic Grinding Operations
Four basic grinding processes are illustrated in Figure 1.2. The figure shows examples of peripheral grinding of flat surfaces and cylindrical surfaces. The figure also shows examples of face grinding of nonrotational flat surfaces and face grinding of rotational flat surfaces. Face grinding of rotational flat surfaces can be carried out on a cylindrical grinding […]
Heat Convection by Coolant and Chips
A note of caution should be sounded for deep grinding where the long contact length allows substantial convective cooling from the grinding coolant. Also in high-rate grinding with low specific energy, the heat taken away by the grinding chips reduces maximum temperature very substantially [Rowe and Jin 2001]. Allowance can be made for convective cooling […]
Grinding Wheels
4.1 INTRODUCTION 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 […]
CFRP Wheel Hubs
The current limit for steel-cored vitrified CBN wheels due to stresses in the abrasive layer from core expansion is considered to be 200 m/s. This will vary somewhat depending on the particular bond and layer depth. However, for speeds of 160 m/s and greater the steel is sometimes replaced with a material of comparable elastic […]
The Shape and Structure of Diamond
The principal crystallographic planes of diamond are the cubic (100), dodecahedron (011), and octahedron (111). The relative rates of growth on these planes are governed by the temperature and pressure conditions, together with the chemical environment during both growth and, in the case of natural diamond, possible dissolution during its travel to the earth’s surface. […]