CENTRELESS GRINDING

THIS PRESENTATION ON CENTRELESS GRINDING REGARDING THE MANUFACTURING SUBJECT, THIS PPT PRESENTED AT B&B INSTITUTE OF TECHNOLOGY.

HOPE IT WILL HELPED THE ENGINEERING STUDENT.

1. WELCOME CENTERLESS GRINDING CREATED BY: HARSH S. DAVE ( 156050319###) B&B INSTITUTE OF TECHNOLOGY 1 UNDER GUIDE BY: PROF. Hitesh Soni

2. OBJECTIVE Definition of Centerless grinding. Describe the relationship between the three main components used in cenerless grinding. Describe advantages of centerless grinding. Describe the component of the centerless grinding. Describe how the regulating wheel determines workpiece rotational speed. Indentify Grinding wheel Imbalance FIGURE 2. The regulating wheel is anglead slightly to enable workpiece through feed. 2

3. Definition Of Centerless Grinding Centerless grinding is a machining process that uses abrasive cutting to removal material from a workpiece . 3

4. Centerless Grinding. 4 Common type of Cylindrical grinding. Three main parts are used. i ) Grinding wheel ii) Regulating wheel iii)Work Rest Blade This component hold the work piece horizontally. Rotate it & Grain its Surface. Each component plays the roll in the grinding process. FIGURE: A Typical centerless grinding configuration

5. How The Centerless Grinding Works. The work rest blade supports the part slightly. It is made of wear-resistant material. The regulating wheel rotates the Cylindrical parts. It is commonly made of plastic or rubber bond. The actual grinding is performed by Grinding wheel. Both the wheel must be periodically dressed and trued to maintain precise roundness of the workpiece FIG . Shows a typical machine built for Centerless Grinding. 5

6. The parts they Grind always must be round. However, Setup is fast And the process Can be automated. 6

7. Advantages Of Centerless Grinding It Enables Fast, accurate production of complicated hand-held parts or workpiece that require Tight Tolerances. Decrease grinding time. Automatic Feeding method. Reduce grinding wheel wear. Grinding of longer parts. Low Maintenance. 7 FIGURE: center less grinding is often used to produse small Parts such as bearings. Centerless grinding is often used to mass production small parts such as bolts , shafts, bearings, hubs or valves.

8. Main categories of centerless grinding. Generally, all centerless grinder fall under two main categories. i ) Angular-bed-grinders ii)Horizontal-bed-grinders On an angular-bed-grinder, the rotating regulating wheel rotates the part @ specific rate . Angular-bed-grinders are usually used to grind heavier workpieces or workpieces that require a fine surface finish. The horizontal-bed centerless grinder is the most common design. The parts being to rotate only after it touches the rotating grinding wheel. 8

9. Main Component Of machine. A cast iron bed supports the grinder and contains the grinding and regulating wheel head assembly and hydraulic reservoir. A wheel head contains the grinding wheel and grinding wheel spindle. A swivel plate is mounted to the bed and tilts or aling the regulating wheel parallel to the grinding wheel. A lower slide is attached to the swivel plate and moves the regulating wheel and workrest blade towards or away from the workrest blade. 9 FIG. The main component of centerless grinder

10. An upper slide is attached to the lower slide and moves the regulating wheel towards or away from the workrest blade. A regulating wheel housing is mounted to the upper slide and houses the regulating wheel houses the regulating wheel and regulating wheel spindle. A work rest is mounted to the lower slide and supports the work rest blade. 10

11. The Regulating Wheel & Workpiece Rotational Speed. During centerless grinding, the Regulating wheel plays a key role in the grinding of workpiece. Two key factors that the regulating wheel controls are rotational speed of the workpiece and the feed rate of the workpiece. The surface speed of the regulating wheel controls the rotational speed, or work speed , of the workpiece. During a centerless grinding operation, the regulating wheel rotates the workpiece by rotating against it, as shown in fig. 11 FIG: The regulating wheel rotates the workpiese by revolving against it a uniform rate.

12. Surface speed is the uniform rate at which the regulating wheel revolves against the workpiece. Surface speed rate is measured in revolutions per minute (RPM). Most regulating wheel revolves between 30 and 40 rpm. The work speed of the workpiece is approximately equal to the regulating wheel surface speed. 12

13. Detecting Grinding wheel Imbalance A simple method for detecting wheel imbalance is to take a wheel that has been mounted on a mandrel. It is set between two equal points, such as the balancing stand shown in fig. If the wheel stays at rest, even if it rotated to a new position, it is said to be static balance. If the wheel is then pushed along the stand, and it rotates smoothly, stopping only when it loses momentum, the wheel is said to be in dynamic balance. If the wheel is out of balance , it will rock back and forth before coming to rest with its heaviest side down. 13 FIG: Placing a grinding wheel on a balancing stand will determine if one side is heavier than another.

14. 14 Thank you!!! If you have any queries, I will try my best to Answer or assist you.