Introduction:
Centreless grinding is a machining process that uses abrasive cutting to remove material from a workpiece. It differs from centered grinding operations in that no spindle or fixture is used to locate and secure the workpiece. Instead, the workpiece is supported between two wheels - the grinding wheel and the regulating wheel. The axial feed rate is an important parameter in centreless grinding, as it determines the rate at which material is removed from the workpiece.

Factors influencing the axial feed rate:

1. Grinding wheel diameter:
The grinding wheel diameter plays a significant role in determining the axial feed rate. A larger grinding wheel diameter will result in a higher feed rate, as there is a larger contact area between the grinding wheel and the workpiece. This increased contact area allows for more material to be removed per revolution of the grinding wheel.

2. Regulating wheel diameter:
The regulating wheel diameter also affects the axial feed rate. A larger regulating wheel diameter will result in a higher feed rate, as it increases the speed at which the workpiece is fed through the grinding zone. This is because a larger regulating wheel diameter increases the peripheral speed of the workpiece, leading to a higher feed rate.

3. Speed of grinding wheel:
The speed of the grinding wheel is another parameter that influences the axial feed rate. A higher speed of the grinding wheel will result in a higher feed rate, as it increases the rate at which material is removed from the workpiece. This is because a higher speed of the grinding wheel leads to a higher cutting velocity, resulting in a higher feed rate.

4. Speed of regulating wheel:
Similarly, the speed of the regulating wheel also affects the axial feed rate. A higher speed of the regulating wheel will result in a higher feed rate, as it increases the rate at which the workpiece is fed through the grinding zone. This is because a higher speed of the regulating wheel leads to a higher peripheral speed of the workpiece, resulting in a higher feed rate.

Conclusion:
In summary, the parameters that influence the axial feed rate in centreless grinding are the grinding wheel diameter and the speed of the regulating wheel. A larger grinding wheel diameter and a higher speed of the regulating wheel will result in a higher feed rate. These parameters should be carefully considered and optimized to achieve the desired material removal rate and surface finish in centreless grinding operations.