Manufacturers wish to increase grinding rates for several reasons: • To increase output from each grinding machine • To increase output by each machine operator • To reduce cost per part An experimental investigation of high removal-rate centerless grinding applied to steel and cast iron allowed process limit charts to be defined [Rowe, Bell, and […]
Рубрика: Handbook of Machining with Grinding Wheels
Theory of the Formation of the Workpiece Profile
Dall [1946], in the first analytical approach to predicting roundness, used two basic parameters, the tangent angle в and the top workrest angle у shown in Figure 19.4. He calculated the magnitude of the error reproduced on the workpiece as a result of one already occurring at its point of contact either with the workrest […]
AVOIDING CRITICAL FREQUENCIES
19.14.1 Vibration Frequencies at Threshold Conditions Figure 19.59 shows a stability threshold plotted against vibration frequency rn for n = 25.0 to n = 26.1. The vibration frequency for a dynamic stability threshold mainly lies just above the natural frequency (O0 of the main machine vibration mode. Figure 19.59 has four distinct zones. These are […]
Grinding Wheel Wear
9.1 THREE TYPES OF WHEEL WEAR 9.1.1 Introduction As a result of process forces during grinding, a grinding wheel is subject to modification by a process of wheel wear. Wear leads to changed process conditions and quality deviations in the component. Figure 9.1 shows three different types of grinding wheel wear: profile deviation, roundness deviation, […]
GRINDING FLUID NOZZLES
10.9.1 Basic Types of Nozzle System The performance and characteristics of the cooling lubricant nozzle for the supply liquid lubricant have a major influence on the grinding result. A number of different nozzles have been developed in order to meet the requirements of various applications. Some of these nozzles are described in greater detail in […]
Contact-Based Workpiece Sensors for Surface Integrity
The best way to investigate the influence of any cutting or grinding process on the physical properties of the machined workpiece would be to directly measure on the generated surface. Until now only very few sensors are available to meet this demand. Two techniques are explained that have the highest potential for this purpose. The […]
Cobalt-Based Alloys
The third group of alloys is cobalt based. These alloys display the best high-temperature corrosion resistance but have the lowest grindability and are the most expensive. They are, therefore, used in just the hottest part of the engine. However, one area where expense is not so important and where strength and corrosion resistance are critical […]
GUIDEWAYS
15.3.1 Introduction Guideways are the elements or surfaces that carry and guide the moving elements such as workpiece holder/drives and wheel and dresser heads. Guideways can be divided into two categories— sliding and rolling element. Guideways of either type are often known simply as slideways. Their selection is dependent on many factors such as speed, […]
Hydrodynamic Spindle Bearings for Large Wheels
To improve damping characteristics, part finish, and wheel roundness, a number of Japanese machine tool builders, in particular, have revisited the use of hydrodynamic spindle bearings [Shigiya 2 n. d., Okuma n. d.,Toyo n. d., Kondo 1998]. Hydrodynamic bearings were popular in older grinding machines due to their reliability, good accuracy, and long life. The […]
Double-Barrel Plunge-Form Dresser
Figure 15.52 shows a double-barrel infeed carrier with hydraulic-mechanical compensator for plunge form dressing used on a Cincinnati 480 30° plunge centerless grinder. It replaced a hydrostatic single-point dresser unit and was equipped with a DFW-HHD heavy-duty hydraulic spindle. FIGURE 15.52 Hydraulic-mechanical compensator plunge infeed system for centerless grinder. 15.18.6 Triple-Barrel Infeed Carrier with Hydraulic-Mechanical […]