Patent ID: 6729936
Filing Date: 2004-05-04
Classification: B24B

Abstract:
An apparatus for measuring a circularity deviation of a cylinder of an object intended to be integrally rotated about a rotation axis, the cylinder being eccentric as either intended or not with the rotation axis, the apparatus comprising:a first measuring device for measuring a circumferential surface of the cylinder at each measuring point â€œpâ€  thereon in a three-point contact method; a motion controlling mechanism for permitting the first measuring device to be moved along a circumference of the cylinder, which circumference lies on a cross section of the cylinder perpendicular to the rotation axis, in contact with the circumferential surface of the cylinder, during rotation of the cylinder about the rotation axis; a circularity deviation calculating device for calculating the circularity deviation of the cylinder, on the basis of a relative position â€œxâ€  of the rotation axis relative to the apparatus for measuring the circularity deviation, a rotating angle &PSgr; of the cylinder about the rotation axis, and an output â€œyâ€  of the first measuring device, wherein the first measuring device includes a plurality of sensors each for measuring the cylinder, such that the plurality of sensors are arranged at different phase angles &THgr; about an original point O defined to be located at or near a center of the circumference of the cylinder.