Abstract: A reference block 30 attached to a housing 20a is moved together with a main spindle 20 to a measurement start position A1, and the reference block 30 is so moved in a Z-axis direction as to across air injected from an air injection nozzle 25, so that a thermal displacement of the main spindle 20 is calculated based on change in pressure measured in the movement. The outer circumference of a tool mounted on the main spindle 20 is brought close to a leading end face of the air injection nozzle 25, and the air is injected to the outer circumference of the tool while rotating the tool at a predetermined position, and the air pressure is measured so that the rotational deflection of the tool is calculated based on the change in the measured pressure.

Abstract: A reference block 30 attached to a housing 20a is moved together with a main spindle 20 to a measurement start position A1, and the reference block 30 is so moved in a Z-axis direction as to across air injected from an air injection nozzle 25, so that a thermal displacement of the main spindle 20 is calculated based on change in pressure measured in the movement. The outer circumference of a tool mounted on the main spindle 20 is brought close to a leading end face of the air injection nozzle 25, and the air is injected to the outer circumference of the tool while rotating the tool at a predetermined position, and the air pressure is measured so that the rotational deflection of the tool is calculated based on the change in the measured pressure.

Abstract: A taper correcting apparatus for a grinding machine comprises: workpiece supporting means for supporting a workpiece in parallel with a grinding wheel spindle; a cutting and feeding device which moves back and forth a cylindrical grinding wheel with respect to said workpiece; a wheel slide which is attached to a bed so as to be movable back and forth with respect to said workpiece; a pair of grinding wheel bearing pedestals which rotatably support ends of said grinding wheel spindle via bearings with respect to said wheel slide, respectively; a first grinding wheel bearing pedestal support which is fixed to said wheel slide, and which clampingly supports one of said grinding wheel bearing pedestals; a second grinding wheel bearing pedestal support which is attached so as to be rotatable about a round shaft, and which clampingly supports another one of said grinding wheel bearing pedestals, said round shaft being attached below said grinding wheel spindle to said wheel slide in parallel with the center line of