Optics: measuring and testing – Dimension – Width or diameter
Reexamination Certificate
2002-04-26
2004-08-17
Stafira, Michael P. (Department: 2877)
Optics: measuring and testing
Dimension
Width or diameter
Reexamination Certificate
active
06778286
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for measuring distortion of a cylindrical body which is suitably used for measurement of radial distortion of a cylindrical body, such as an inner or outer ring of a bearing.
2. Description of the Related Art
In general, when an inner ring Ci or an outer ring Co of a ball bearing M shown in
FIG. 8
has a distortion in the radial direction, a raceway groove Cis or a groove Cos for guiding balls B exhibits waviness. When such a ball bearing M is used, axial vibration is generated, making smooth and stable rotation unattainable. Therefore, distortions of the inner ring Ci and the outer ring Co must be minimized. That is, when the inner ring Ci is rotated one turn with the position of its lower end surface Cid fixed, radial distortion Ed as measured at an upper end surface Ciu of the inner ring Ci ideally becomes zero. However, in actuality, some distortion Ed is present and must be reduced to a specified tolerance.
Incidentally, such distortion Ed has conventionally been measured by use of an electronic micrometer as disclosed in, for example, Japanese Patent Application Laid-Open (kokai) No. 8(1996)-261710.
FIG. 9
shows a conventional distortion measurement apparatus
60
capable of measuring distortion Ed by use of an electronic micrometer. The distortion measurement apparatus
60
has a holding plate
62
which is disposed on the top face of a base block
61
and has a V-shaped holding depression
62
s
. A peripheral surface of a lower end of a cylindrical body C (e.g., an inner ring Ci) is brought into contact with the holding depression
62
s
. A probe
63
s
of an electronic micrometer
63
is brought into contact with an upper portion of the peripheral surface of the cylindrical body C at a position diametrically opposite the holding depression
62
s
. During measurement, after a conical portion
64
of a rotation jig
65
is pressed against an inner edge of the cylindrical body C, an operator rotates the cylindrical body C over one turn, and obtains distortion Ed from variation measured by the electronic micrometer
63
. When the thus obtained distortion Ed falls outside the specified tolerance, the operator judges the cylindrical object to be defective.
However, such a conventional distortion measurement apparatus
60
has the following drawbacks.
First, because of mechanical contact involved in measurement, measurement error increases, especially in measurement of a small cylindrical body C, such as a small inner ring Ci whose outer diameter is not greater than several millimeters. Therefore, precise measurement cannot be performed with high reproducibility.
Second, since a major portion of measurement work must be performed manually by an operator, measurement requires time and labor, and stable, reliable measurement cannot be performed.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus for measuring distortion of a cylindrical body which eliminates mechanical contact and enables performance of precise measurement with high reproducibility.
Another object of the present invention is to provide an apparatus for measuring distortion of a cylindrical body which facilitates realization of fully-automated operation, eliminates manual operation, and enables stable, reliable measurement.
In order to achieve the above objects, an apparatus for measuring distortion of a cylindrical body according to the present invention includes: a stationary straight rail provided on a flat surface; a cylindrical-body transfer mechanism for rolling the cylindrical body such that a peripheral surface of one end of the cylindrical body remains in contact with the stationary straight rail; a reference pole disposed at a position separated a predetermined distance from the cylindrical body in a direction perpendicular to the rolling direction of the cylindrical body; a laser scan micrometer capable of simultaneously scanning the other end of the cylindrical body and the reference pole by means of laser beam projected toward the rolling direction to thereby measure a distance between the cylindrical body and the reference pole; and a control section for controlling the cylindrical-body transfer mechanism and the laser scan micrometer and for processing measurement data output from the laser scan micrometer to thereby obtain distortion. By virtue of the above-described configuration, radial distortion of the cylindrical body can be measured.
REFERENCES:
patent: 4410278 (1983-10-01), Makihira et al.
patent: 4483615 (1984-11-01), Bieringer et al.
patent: 5602646 (1997-02-01), Bernardin et al.
patent: 6449034 (2002-09-01), Marchand et al.
patent: 6531672 (2003-03-01), Malloy
patent: 8-261710 (1996-10-01), None
Sakaguchi Iwao
Takeshige Yoshio
Birch & Stewart Kolasch & Birch, LLP
Minebea Co. Ltd.
Stafira Michael P.
LandOfFree
Apparatus for measuring distortion of cylindrical body does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for measuring distortion of cylindrical body, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for measuring distortion of cylindrical body will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3312486