JP2001141440A - Spherical size measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate accuracy in the size of a spherical body by reexamining and redefining the conventional definitions of dimension size irregularities and diameter size variations and using the redefined dimension size irregularities and diameter size variations. SOLUTION: A first and second taper cones 4 and 5 are rotated in such a way that they are rotated in the opposite directions as rotating a drive roller 3 to measure the mean diameter size d0 of a rotator 2 in a state of no skew. Then the drive roller 3 is halted to rotate the first and second taper cones 4 and 5 in the same directions by the amount of the changes of the axes of rotation and to incline the taper cones 4 and 5 only by an angle of β with respect to the horizontal direction to form new axes of rotation, and a mean diameter size d0 is measured again at the location. By repeating the operations, the mean diameter size d0 of each cross section set at a few locations or more is acquired, and a candidate diameter size D, a diameter size irregularity Δd, and a diameter size variation ΔD, etc., are computed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for measuring the size of a sphere, and more particularly, to a method for measuring the size of a sphere for measuring the dimensional accuracy of a sphere such as a rolling element which is a component of a rolling bearing.

[0002]

2. Description of the Related Art Conventionally, the outer diameter of a sphere such as a rolling element of a rolling bearing has been measured by a dimension measuring device as shown in FIG.

[0003] That is, the dimension measuring device includes a support bar 1.
01 is erected on the base 102 and the support bar 10
From 1, a measuring head 104 provided with an electric micrometer 103 protrudes. The rolling element 106 is inserted or passed between the anvil 110 placed on the base 102 and the electric micrometer 103, and the distance between two points on the diagonal line of the rolling element 106 is measured by the electric micrometer 103. The absolute value of the diameter dimension is calculated by calculating the diameter dimension by comparing with the master ball.

Conventionally, the diameter is measured at several measurement points by rotating the rolling element 106 at a predetermined angle, and the average of the diameters of one sphere is represented by the representative diameter D. 'And the maximum value of each diameter dimension d'max
(Σ: standard deviation) (hereinafter, referred to as “variation 6σ”), which is the difference between the difference between the rolling element 106 and the minimum value d′ min or the control limit of the probability statistical variation, is referred to as “variation 6σ”. And Further, in the rolling bearing, a plurality of rolling elements 106 are incorporated as one set, and the difference between the maximum value D'max and the minimum value D'min of the representative diameter dimension D 'of each rolling element 106 or the representative diameter dimension D''Variation 6σ
Is the diameter difference Δ between the plurality of rolling elements 106.
D ′, and the maximum value of the diameter difference Δd ′ of each rolling element 106 is calculated as the diameter dimension difference ΔD′max between the plurality of rolling elements, and the dimensional accuracy between the plurality of rolling elements incorporated in the rolling bearing is calculated. Has been evaluated.

Incidentally, a hard disk drive (HD) mounted on a personal computer (personal computer) or the like.
D) In the rolling bearing, a non-repeat rotary component (non-repeatab) indicating a component other than vibration periodically generated by rotation.
le run out (hereinafter referred to as “NRRO”) is required to be highly accurate, and the sound generated from the rotating part is required to be small and to have low torque.

As a measure for improving the accuracy of NRRO from such a viewpoint, "swelling" of the race and the rolling element is considered.
Rolling bearings in which the component of (waviness) is small, especially the even-numbered mountain component of the rolling element has been already proposed (JP-A-8-247151 and JP-A-8-247153).

According to this prior art, for example, the rolling element 1
In the case where the number of “undulations” of 06 is an even number, FIG.
As shown in the figure, both ends of the diameter of the rolling element 106 are simultaneously located at the top or the bottom of the "undulation", and the difference between the diameter a between the top and the diameter b between the bottoms becomes large, which causes vibration. Become. On the other hand, if the number of undulations is odd,
As shown in FIG. 15 (b), one end of both ends of the diameter of the rolling element 106 is located at the top of the "undulation" and the other end is located at the bottom of the "undulation", so that the respective diameters r1, r2, r
There is almost no difference between the three and there is no influence on the rotation accuracy.

That is, when the number of "undulations" is an odd number, the influence on the rotational accuracy is relatively small, but when the number of "undulations" is even, the difference between the diameter dimension a and the diameter dimension b is large. It is thought that the accuracy of NRRO can be improved by easily reducing the even-numbered peak component of the “swell” because it easily becomes a source of vibration or the like.

It is known that the component that has the greatest influence on the NRRO is the revolution period component of the rolling element 106 (= rotation component of the cage; hereinafter, referred to as “Fc component”). Fc of variation in diameter of 106
The effects on components have also been elucidated through various analyzes and experiments.

That is, for example, as shown in FIG.
When eight rolling elements 106 are incorporated between the outer ring 107 and the inner ring 108, the rolling elements 106 are numbered in descending order of the diameter dimension. 1 to No. As shown in FIG. 16A, when the rolling elements 106 having the smallest difference in diameter among the plurality of rolling elements are arranged diagonally to each other, as shown in FIG. Since the eccentricity of the center of the groove is small, the Fc component, which is the runout of the rolling element revolution synchronization, has a minimum value δmin.
On the other hand, as shown in FIG. 16B, when the rolling elements 106 having the largest difference in diameter between a plurality of rolling elements are arranged diagonally to each other, the center of the outer ring groove and the inner ring groove The eccentricity of the center becomes maximum and the Fc component becomes the maximum value δmax.

Therefore, when the rolling elements 106 are appropriately incorporated in a large number of rolling bearings, the probability density function of the Fc component shows a normal distribution as shown in FIG. The components have a relationship as shown in FIG.

That is, the larger the diameter difference ΔD ', the wider the distribution range of the normal distribution, and the larger the Fc component. Therefore, it is considered that the maximum value δmax and the minimum value δmin approach each other by reducing the diameter dimension difference ΔD ′, so that the Fc component can be reduced.

[0013]

As described above, the diameter dimension difference Δd 'is determined by the maximum value d'max and the minimum value d'min of the diameter dimension d' of the rolling element 106 and the diameter dimension d '.
Is calculated on the basis of the variation 6σ of the sphere, and thus represents the characteristics of the sphere in a stationary state. However, the rolling element 106 rolls while performing a skew motion over time during rotation.

That is, in a rolling bearing, FIG.
As shown in FIG.
07a and a rolling axis c (contact angle γ) so as to roll at two contact points between the raceway groove 108a of the inner ring 108 and the rolling element 10
Numeral 6 skews little by little with the passage of time, and rotates on the rotation axis c while sequentially changing the inclination of the rotation axis c.

Therefore, the Fc component is determined in a short time by the combination of the diameters d 'of the rolling elements 106 as shown in FIG. The diameter dimension changes due to the change in c, that is, the diameter dimension difference Δd '. That is, the Fc component is affected by the diameter dimension difference ΔD ′ and the diameter dimension non-uniformity Δd ′ that normalize the combination order of the rolling elements 106.

However, as described above, the diameter dimension difference Δ
When d ′ is calculated as the difference between the maximum value d′ max and the minimum value d′ min of the diameter dimension d ′ of the rolling element 106, the diameter dimension difference Δd ′ is determined by the circumscribed sphere to the outer ring 107 and the inner ring 108.
In the process of the skew motion in which the rotation axis c changes, the diameter difference Δd ′ calculated above is not directly related to the Fc component. there were.

The present invention has been made in view of the above problems, and has been reviewed and redefined the conventional definitions of the nonuniformity of the diameter and the mutual difference of the diameters, and the redefined nonuniformity of the diameter and the diameter It is an object of the present invention to provide a sphere size measuring method and a measuring device capable of evaluating the dimensional accuracy of a sphere using the mutual difference.

[0018]

As shown in FIG. 1, a rolling element 2 as a sphere incorporated in a rolling bearing has a microscopically irregular outer peripheral surface as shown in FIG. Is generally defined as the difference between the maximum value d'max and the minimum value d'min of the rolling element 2, that is, defined by equation (1).

Δd ′ = d′ max−d′min (1) On the other hand, in a rolling bearing, the rotation speed Nb of the rolling element 2 when the outer ring is rotating and the inner ring is stopped is determined by the rotation speed of the outer ring. Ne, where dm is the pitch circle diameter (PCD) of the rolling bearing, and is expressed by equation (2).
Is known to be represented by Equation (3).

[0020]

(Equation 1)

Here, γ is the contact angle of the rolling element 2.

Therefore, equation (4) is established from equation (2), and equation (5) is established from equation (3).

Nb> Ne (4) Ne> Nc (5) Therefore, Expression (6) is established from Expressions (4) and (5).

Nb> Nc (6) That is, the conventional diameter difference Δd ′ is a value that governs the rotation speed Nb of the rolling element 2 and the rotation speed Nb of the cage.
Is not a value that governs the rotation speed N of the rolling element 2
b is considerably higher than the rotation speed Nc of the cage.

Therefore, when the distance between two points is measured and the diameter difference Δd ′ is calculated as in the conventional case, the diameter difference Δd ′ represents the characteristic of the rolling element 2 in the stationary state, and In order to directly evaluate the effect of the Fc component, which is the rotational component of the cage, on the rolling bearing without directly relating the effect of the Fc component in the course of the skew movement of the rolling element 2 with the passage of time. It is considered necessary to review the calculation method (definition) for the nonuniform diameter.

[0026] As a result of the present inventors have made intensive studies, the plane of rotation of the rolling elements, that is, "deviation" from the average diameter d ₀ of the rolling element 2 was measured so as to pass through a section dominated the vibration,
Therefore, it was found that the Fc component was most affected.

[0027] That is, for each rolling element 2, at each cross-section of more than a few points to calculate the average diameter d _0, representative diameter D of the rolling elements 2 average value of the individual average diameter d ₀ of the calculated and then, the maximum value dmax and a minimum value of the average diameter d ₀ dmi
The influence of the Fc component during the skew movement can be directly evaluated by setting the difference from n (or the variation 6σ) as the diameter dimension difference Δd. Then, based on the newly defined representative diameter dimension D and diameter dimension difference Δd, the diameter dimension difference ΔD between the plurality of rolling elements 2 and the diameter dimension difference ΔDmax for the plurality of rolling elements 2 are redefined. Thus, the characteristics of the rolling elements 2 during the skew motion can be appropriately evaluated.

Therefore, the sphere size measuring method according to the present invention is a sphere size measuring method for measuring dimensional accuracy between a plurality of spheres, wherein the dimensional size is measured in one section of each sphere and the dimensional size is measured. Calculate the average diameter in one cross section of the individual spheres based on
A plurality of cross sections are set for each of the individual spheres, the average diameter in each cross section is calculated, and the average value of the average diameters is used as the representative diameter of each sphere, and the average diameter is calculated. The difference 6σ (σ is a standard deviation) obtained by statistically processing the difference between the maximum value and the minimum value or the average diameter is regarded as the diameter of each sphere, and further calculated for a plurality of spheres. The difference between the maximum value and the minimum value of each representative diameter or the variation 6σ obtained by statistically processing the representative diameter is defined as the diameter difference between the plurality of spheres, and the diameter of each sphere is different. The method is characterized in that the maximum value is set to be the same as the diameter of the plurality of spheres, and the accuracy of the diameter between the spheres is measured.

Specifically, in FIG. 1 described above, the diameter d of the rolling element 2 at the angle θ is represented by Expression (7).

[0030]

(Equation 2)

Here, d ₀ indicates the average diameter and φn indicates the phase.

Therefore, when the equation (7) is integrated between 0 and π, the second term on the right side becomes “0”, and the equation (8) is established.

[0033]

(Equation 3)

Therefore, the average diameter d ₀ in one section of the rolling element 2 is given by the following equation (9).

[0035]

(Equation 4)

Then, as described above, the second right side of the equation (7)
Since the term becomes “0” by semicircular integration, the average diameter dimension d ₀ indicates the diameter dimension d in the cross section.

In the rolling bearing for HDD, the diameter of the rolling element 2 is small (for example, 2 m in diameter).
m), rotating the rolling element 2 a plurality of times coaxially (for example, 5 to 10
It is desirable that the value obtained by the rotation) be an average diameter d ₀ . Therefore, equation (9) can be rewritten as equation (10).

[0038]

(Equation 5)

Here, m is the number of rotations when the rolling element 2 is rotated.

Next, the rolling element 2 is skewed to set several or more cross sections, and the average diameter d ₀ (diameter d) of each cross section is measured.

More specifically, the rotation axis of the rolling element 2 is defined as the II axis, and the angle between the projection of the II axis on the xy plane and the x axis in the xyz coordinate axis of FIG. If the angle formed with the z-axis is θz, the II axis is a parameter of the angles θx and θz.

Accordingly, the angles θx and θz are 0 °
Any combination between 180 ° (0 to π radians) is possible. The angles θx and θz are determined, the diameter d is measured in n cross sections, and the average diameter d _{0 is} calculated from the diameter d.
Can be calculated.

Conventionally, as shown in FIG. 3, the diameter d is defined as the distance between two points, that is, the diameter d ', assuming that the xy plane is the rotation axis plane A and the meridian measurement trajectory B is drawn. However, in order to obtain a diameter dimension d at each cross-section by setting several or more cross-sections and passing through each cross-section as in the present invention, measurement of the diameter dimension d in three dimensions is required. In order to achieve this, it is necessary to obtain the diameter d by drawing a hand-shaped measurement trajectory C as shown in FIG.

Then, the average value d ₀ ave of the average diameters d ₀ at n locations becomes the representative diameter D of the rolling elements 2. That is, the representative diameter dimension D of the rolling element 2 is given by the following equation (1).
It becomes like 1).

D = d ₀ ave = Σd ₀ / n (11) Then, the difference between the maximum value dmax and the minimum value dmin of the average diameter dimension d ₀ at n locations is defined as the diameter dimension difference Δd, and For each of the rolling elements 2, a representative diameter dimension D is calculated in the same manner as described above, and then the difference between the maximum value Dmax and the minimum value Dmin of the representative diameter dimension D or the variation 6σ obtained by statistical processing is calculated as the diameter dimension. The difference ΔD is redefined as the mutual difference, and the maximum value of the diameter inequality Δd for each rolling element 2 is defined as the diameter inequality ΔDmax for a plurality of rolling elements 2. These newly defined representative diameter dimensions D, The diameter dimension difference Δd of the rolling elements 2, the diameter dimension difference ΔD between the plurality of rolling elements, the diameter dimension difference Δ of the plurality of rolling elements
Dmax is calculated, so that even if the rotation axis sequentially changes with time due to skew motion, it is possible to appropriately evaluate the Fc component in the rolling bearing.

In order to draw a hand-shaped measurement trajectory,
The rolling element 2 is supported by the first and second tapered members and the driving roller.
And then rotate the drive roller to rotate the first and second
At the same speed so that they are in opposite directions.
Roll the rotating shaft of the rolling element 2 in a state where skew does not occur.
(The y-axis in FIG. 2), the diameter dimension d, that is, the average diameter dimension d
₀After that, the drive roller is stopped, and the first and the second are stopped.
Rotation axis change of the second taper member in the same direction and at the same speed
Turn the taper member by an angle
A new rotation axis is formed by inclining by β degrees,
And the average diameter dimension d as described above.₀Measure (diameter dimension d)
You.

By repeating such an operation, the average diameter d at each cross section set at several places or more is obtained.
₀ (diameter dimension d), and based on the average diameter dimension d ₀ , data affecting the Fc component such as the representative diameter dimension D, the diameter dimension difference Δd, and the diameter dimension difference ΔD can be obtained. .

[0048]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a perspective view showing one embodiment of the method for measuring the size of a sphere according to the present invention. The rolling element 2 as an object to be measured is rotatable in the direction of arrow D at a rotation speed N1. Drive roller 3 and a first tapered cone 4 rotatable in the direction of arrow E (forward and reverse directions) at a rotation speed N2.
And a second taper cone 5 rotatable in the direction of arrow F at a rotation speed N3.

That is, on the xyz coordinate axes (orthogonal coordinate axes) with the center O of the rolling element 2 as the origin O, the first and second tapered cones 4 and 5 define the center line u between the tapered cones 4 and 5 and the inclination angle α. And x
And a pair of upper and lower tracing styluses (first and second tracing styluses 6 and 7) are arranged on the z-axis so as to be able to touch the rolling elements 2 lightly. Has been established.

In the present measuring method, first, the diameter d of the rolling element 2 in a state where no skew motion occurs is measured.

That is, the driving roll 3 is rotated at the rotation speed N1 in the direction of arrow D, and the second taper cone 5 is rotated.
At the rotation speed N3 in the direction of arrow F (clockwise),
Further, when the first taper cone 4 is rotated in the opposite direction (counterclockwise) to the second taper cone 5 and at the same rotation speed as the second taper cone 4 (N3 = -N2), the rolling element 2 moves around the y-axis. It rotates by m rotations. Then, by measuring the diameter d of the cross-sectional shape in the first and second measuring element 6, the average diameter d ₀ of the cross section from the formula (10) is calculated.

Next, the rolling element 2 is skewed.

That is, the rotation of the drive roll 3 is stopped (N1 = 0), the second taper cone 5 is rotated at a rotation speed N3 in the direction of arrow F, and the first taper cone 4 is rotated.
Is rotated in the same direction as the second taper cone 5 and at the same rotation speed as the first taper cone 4 (N3 = N2) by the angle θz around the z-axis to skew the rolling element 2 (No. 1 skew operation).

Then, the diameter d is measured in the same manner as described above in a state where the rolling element 2 is rotated around the z axis by the angle θz and skewed.

As a result, as shown in FIG. 6, in the first time, the rolling element 2 can measure the diameter d in the cross-sectional shape 2 'with the y axis as the rotation axis, and in the second time, the rolling element 2 rotates by the angle θz. It is possible to measure the diameter d in the cross-sectional shape 2 ″ using the y ′ axis as the rotation axis.

Next, the drive roll 3 is rotated in the direction of arrow D, and the second taper cone 5 is rotated in the direction of arrow F (clockwise).
3, the first taper cone 4 is further rotated in the same direction (clockwise) as the second taper cone 5 and at the same speed as the second taper cone 5 to rotate the rolling element 2 a plurality of times. Due to the effect of the inclination angle β of the second taper cones 4 and 5 with respect to the x-axis, the rotation axis is shifted by θx in the xy plane with respect to the first measurement state (second skew operation).

Therefore, by combining the first skew operation and the second skew operation, the rotation axis of the rolling element 2 can be three-dimensionally changed. In this case, the inclination angle β is small (for example, 5 ° to 10 °).
°), the angle θx and the angle θz can be adjusted almost independently.

Such measurement is performed for several or more cross-sectional shapes to calculate an average diameter dimension d _{0, and} an average value of the average diameter dimension d ₀ is calculated as a representative diameter dimension D of the rolling element 2. the difference with the diameter disparity Δd an average diameter of a maximum value dmax and minimum value dmin of d _0, a plurality of rolling elements 2
, The representative diameter dimension D is calculated in the same manner as described above. Then, the maximum value D of the calculated representative diameter dimension D
Difference between max and minimum value Dmin or variation obtained by statistical processing 6
σ is a diameter dimension difference ΔD, and the maximum value of the diameter dimension non-uniformity Δd of each rolling element 2 is defined by a plurality of rolling elements 2.
直径 Dmax.

Then, the newly defined representative diameter dimension D, the diameter dimension difference Δ for each rolling element 2
d, the diameter difference ΔD between the plurality of rolling elements, and the dimensional difference ΔDmax for the plurality of rolling elements, so that even if the rotation axis sequentially changes with the passage of time due to the skew motion, the Fc component of the rolling bearing Reasonable evaluation becomes possible.

FIG. 7 is a plan view of a sphere size measuring device used in the above measuring method, and FIG. 8 is a front view of FIG.

7 and 8, the drive roll 3 is fitted on the rotating shaft 8a of the drive roll spindle 8, and the drive roll spindle 8 is connected to a servomotor 10 via a coupling 9. In addition, the position of the drive roller 3 is set in the vertical direction (in FIG. 8,
A wedge-shaped roller position adjusting mechanism 26 that adjusts the position (indicated by an arrow G) is additionally provided.

The first taper cone 4 is fitted on a rotation shaft 11 a of a taper cone spindle 11, and the taper cone spindle 11 is connected to a servo motor 13 via a coupling 12.

Similarly, the second taper cone 5 is fitted on a rotation shaft 14 a of a taper cone spindle 14, and the taper cone spindle 14 is connected to a servo motor 16 via a coupling 15.

The tapered cone spindles 11 and 14 are the first
A cone position adjusting function (not shown) is provided so that the second taper cones 4 and 5 can reciprocate in the directions of arrows H and I, and a tilt angle adjusting function (not shown) capable of adjusting the tilt angle α. ) Is attached. In this embodiment, the inclination angle β of the taper cone with respect to the x-axis is fixed (for example, 5 °), and the first and second tracing styluses 6 and 7 are mounted on the measuring heads 19 and 23. At the same time, arm portions 22 and 25 are connected to the measuring heads 19 and 23, and the measuring heads 19 and 23 are coupled to a slide 17 so as to be able to reciprocate in the direction of arrow J, and the slide 17 is connected to a servomotor ( 9 and is supported by a porous air bearing 18 symmetrical with respect to the center of the rolling element 2 as shown in FIG.

Further, the measuring heads 19 and 23 have
As shown in FIG. 0, a Z-shaped parallel spring mechanism 21 and an elastic torque transmitting mechanism 34 are provided, and the position of the measuring heads 19 and 23 in the vertical direction is adjusted by an elastic driving method.

In the contact portion of the rolling element 2 between the first and second tracing styluses 6 and 7, high precision flatness and parallelism are required, and as shown in FIG. Second
Diamond tips 6a and 7a are formed at the tips of the measuring elements 6 and 7, respectively.

Further, since the rolling element 2 used for the rolling bearing for HDD has a small diameter of about 2 mm, as shown in FIG. 12, it is rolled by a suction pipe 35 connected to a vacuum pump (not shown). The rolling element 2 is sucked while the moving element 2 is being sucked.
Is transported to a predetermined position. In this case, since the diameter of the rolling element 2 is small as described above, it is sensitive to a temperature change. Therefore, it is preferable to cover the entire structure with a heat insulating transparent member or use a material having a small coefficient of thermal expansion.

In the spherical dimension measuring apparatus thus configured, the rolling element 2 sucked by the suction pipe 35 is transported to a predetermined position, and the first and second tapered cones 4 and 5 are moved in the directions indicated by arrows H and H, respectively. Move in the direction of arrow I to adjust the position of the first and second taper cones 4, 5,
Further, the roller position adjusting mechanism 26 is operated to drive the driving roller 3.
Adjust the position of. Then, the measuring heads 19 and 23 are adjusted in the direction of arrow J and in the vertical direction, and the position is adjusted so that the first and second tracing styluses 6 and 7 can come into contact with the rolling elements 2.

Thereafter, by controlling the operations of the first and second taper cones 4 and 5 and the driving roller 3, the rolling element 2 is skewed little by little, and as described above, the hand-shaped measurement locus The diameter dimension d can be measured in the measurement cross section while drawing.

The present invention is not limited to the above embodiment.

FIG. 13 is an enlarged view of a main part showing another embodiment of the sphere size measuring device. In this other embodiment, FIG.
The above-mentioned inclination angle α is set to “0”, and the first and second tapered cones 4 and 5 are replaced by first and second tapered disks 41 and 42. By controlling the driving of the second taper disks 41 and 42 and the driving roller 3, it is possible to obtain a hand-shaped measurement trajectory in several or more cross-sectional shapes, and to achieve a dimensional accuracy appropriately corresponding to a skew motion. An assessment can be made.

[0073]

As described above in detail, the method for measuring the size of a sphere according to the present invention measures the diameter of one section of each sphere and averages the diameter of one section of each sphere based on the diameter. Calculate the diameter, then set several or more cross sections for each of the individual spheres, calculate the average diameter in each cross section, and calculate the average value of the average diameters as the representative diameter of the individual spheres And a variation 6σ (σ is a standard deviation) obtained by statistically processing the difference between the maximum value and the minimum value of the average diameter dimension or the average diameter dimension.
Are the diameters of the individual spheres, the diameter inequality directly reflects the Fc component, and even if the rotation axis of the sphere changes with the passage of time, the diameter of the sphere changes due to the diameter inequality. Appropriate evaluation of the effects of vibration is possible. Therefore, while the effect of the Fc component is evaluated in a short time by the difference between the diameters, it can be appropriately evaluated in a long time due to the difference in the diameters.

[Brief description of the drawings]

FIG. 1 is an external view showing an example of a rolling element as an object to be measured.

FIG. 2 is a diagram for explaining a measurement method of the present invention.

FIG. 3 is a diagram showing a conventional measurement trajectory.

FIG. 4 is a diagram showing a measurement trajectory according to the present invention.

FIG. 5 is a perspective view showing one embodiment of a method for measuring the dimensional accuracy of a sphere according to the present invention.

FIG. 6 is a diagram for explaining details of the measurement method of the present invention.

FIG. 7 is a plan view showing an embodiment of a dimensional accuracy measuring device for performing the dimensional accuracy measuring method.

FIG. 8 is a front view of FIG. 7;

FIG. 9 is a view as viewed in the direction of arrows XX in FIG. 8;

FIG. 10 is a front view showing details of a measurement head driving mechanism.

FIG. 11 is an enlarged view of a main part showing details of a contact part of a tracing stylus.

FIG. 12 is a diagram for explaining a method of mounting a rolling element on a dimensional accuracy measuring device.

FIG. 13 is a front view showing another embodiment of the dimensional accuracy measuring device for performing the dimensional accuracy measuring method.

FIG. 14 is a front view of a conventional sphere size measuring device.

FIG. 15 is a diagram for explaining the relationship between the number of undulations and the variation in dimensional accuracy.

FIG. 16 is a view showing the relationship between the outer diameter of a rolling element and an Fc component.

FIG. 17 is a distribution diagram (a) of the arrangement order (combination order) of each rolling element with respect to a large number of rolling elements, and a characteristic diagram (b) showing a relationship between a diameter difference between conventional diameters and an Fc component.

FIG. 18 is a diagram for explaining the relationship between the rolling of a rolling element and a rotating shaft in a rolling bearing.

[Explanation of symbols]

 2 rolling elements (spheres)

Claims (1)

[Claims] 1. A sphere size measuring method for measuring dimensional accuracy between a plurality of spheres, wherein a diameter of one cross section of each sphere is measured, and one cross section of the individual sphere is measured based on the diameter. , And then set several or more cross sections for each of the individual spheres, calculate the average diameter in each cross section, and calculate the average value of the average diameter as a representative of the individual spheres. In addition to the diameter dimension, the difference between the maximum value and the minimum value of the average diameter dimension or the variation 6σ (σ is standard deviation) obtained by statistically processing the average diameter dimension is regarded as the diameter dimension of each sphere, Further, the difference between the maximum value and the minimum value of each representative diameter dimension calculated for the plurality of spheres or the variation 6σ obtained by statistically processing the representative diameter dimension is calculated as the diameter dimension difference between the plurality of spheres. And before The maximum value of the diameter disparity of each sphere as the diameter disparity between the plurality of spheres, sphere dimension measuring method characterized by measuring the accuracy regarding the diameter between the respective spheres each other.