Centreless grinding: factors affecting axial feed rate Which parameters primarily influence the axial feed rate of the workpiece in centreless through-feed grinding?

Introduction / Context:
In centreless through-feed grinding, work does not rely on centers or chucks. The regulating wheel imparts rotation and axial feed, while the grinding wheel removes material. Understanding what drives feed rate is essential for productivity and roundness control.

Given Data / Assumptions:

• Through-feed setup with a work-rest blade.
• Steady-state grinding with properly dressed wheels.

Concept / Approach:
Axial feed rate in through-feed depends on the regulating wheel kinematics and geometry. The axial component of the regulating wheel’s surface velocity, created by tilting its axis by a small angle relative to the grinding wheel axis, pushes the work along.

Step-by-Step Solution:
Diameter of regulating wheel affects surface speed for a given RPM.Regulating wheel speed directly sets tangential velocity and thus axial component.Inclination angle determines the proportion of tangential speed resolved in the work-axis direction → higher angle, higher feed.

Verification / Alternative check:
Feed per minute ≈ V_reg * sin(theta), where V_reg is regulating wheel peripheral speed and theta is the inclination angle; diameter influences V_reg for fixed RPM.

Why Other Options Are Wrong:

• Focusing only on grain size ignores the kinematic origin of feed; grain size affects finish and forces, not the primary feed mechanism.

Common Pitfalls:
Confusing grinding wheel speed with feed control; in centreless grinding, the regulating wheel governs feed and rotation.

Final Answer:
All of the above