Creep feed grinding apparatus

A creep feed grinding apparatus comprising:

• a chuck table having a holding surface for holding a workpiece under suction thereon;
• a grinding unit having a spindle rotatable about a longitudinal axis thereof and a grinding wheel mounted on a lower end of the spindle, the grinding wheel including an annular base and a plurality of grindstones disposed in an annular array on a surface of the annular base, the grinding wheel including an annular track having an outside diameter larger than a diameter of the chuck table, the grindstones being in the annular track;
• a moving mechanism for moving the chuck table and the grinding unit relative to each other along a X-direction, which is perpendicular to the longitudinal axis of the spindle;
• and
• a bottom surface state adjusting mechanism for adjusting states of bottom surfaces of the grindstones by cleaning, correcting or cleaning and correcting the bottom surfaces of the grindstones that are held in contact with the workpiece on the holding surface when the grinding unit grinds the workpiece in a creep feed grinding mode, the bottom surface state adjusting mechanism having a longitudinal axis and being positioned below the annular track so that the longitudinal axis of the bottom surface adjusting mechanism is transverse to the bottom surfaces of the grindstones,
• wherein the bottom surface adjusting mechanism is positioned outside of a relative movement area of the chuck table in which the chuck table and the grinding unit are moved in the X-direction by the moving mechanism between a first position in which the chuck table is separated from the grinding wheel and a second position in which the chuck table is completely under the grinding wheel and the grindstones are contacting the workpiece, and the bottom surface adjusting mechanism is outside of the chuck table in the first position and the second position.