JP2007093544A - Axial direction vibration measuring method and vibration measuring apparatus of rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED To accurately measure the vibration characteristics in the axial direction of a rolling bearing 1.
An axial load is applied to an inner ring 3 via an elastic member 20 having a spring constant smaller than that of the rolling bearing 1 with respect to the rigidity in the axial direction of the rolling bearing 1. In this state, the vibration in the axial direction of the inner ring 3 is measured while rotating the outer ring 2. As a result, the member that is displaced together with the inner ring 3 can be lightened, the natural frequency can be increased, and the elastic member 20 can insulate the vibration of the inner ring 3 to solve the above problem.
[Selection] Figure 1

Description

  This invention measures the vibration in the axial direction of a rolling bearing incorporated in a rotating part of a rotating device that requires quietness in use, such as a rolling bearing for supporting a rotating main shaft of a rotating device such as a motor. Use for this purpose.

  Conventionally, the vibration of a rolling bearing for supporting a rotating member of various rotating devices is measured. For example, as shown in FIGS. 4 to 5, while applying an axial load to the outer ring 2 constituting the rolling bearing 1 (in a state where a preload is applied), the inner ring 3 is also rotated by the rotation main shaft 4, The vibration in the radial direction of the outer ring 2 is measured by the vibration pickup 5 that is in contact with or close to the outer peripheral surface of the outer ring 2. On the other hand, in the case of a rotating device that requires quietness when used, for example, a rolling bearing that supports a spindle of a motor or the like, a bracket (bearing housing portion) for supporting the rolling bearing is provided in the radial direction of the rolling bearing. Is often flat (thin plate). When the rolling bearing is supported by such a flat bracket, it is difficult to secure the supporting rigidity in the axial direction of the rolling bearing, and this rolling bearing may easily vibrate in the axial direction. For this reason, in the case of a rolling bearing used in such a state, it is important to suppress the vibration in the axial direction as well as the radial direction in order to ensure the quietness of the rotating device such as the motor. Become.

  In order to suppress the axial vibration of the rolling bearing in this way, the vibration of the rolling bearing in the axial direction is measured and the vibration is evaluated (for example, whether or not the vibration amount is within an allowable range). There is a need. For example, Patent Document 1 discloses a vibration measuring device 6 for measuring vibration in the axial direction of a rolling bearing 1 as shown in FIG. In this vibration measuring device 6, a shaft 8 to be measured is supported via a buffer member 9, such as an O-ring, inside a hollow main spindle 7 that is rotationally driven by an endless belt 14. Therefore, the shaft 8 to be measured rotates in synchronism with the hollow rotation main shaft 7 while allowing displacement in the axial direction inside the hollow rotation main shaft 7. When measuring the vibration of the rolling bearing 1, the inner ring 3 of the rolling bearing 1 is fitted on one end of the shaft 8 to be measured. Then, in a state where the outer ring 2 of the rolling bearing 1 is stopped by a jig (not shown) or the like (rotation is prevented), the hollow rotating main shaft 7 and the measured shaft 8 are rotated while the shaft of the measured shaft 8 is rotated. By detecting the amount of directional displacement by the detector 15, the amount of vibration in the axial direction of the inner ring 3 of the rolling bearing 1 is measured.

  Patent Document 2 describes a vibration measuring device 6a for measuring vibration in the axial direction of the rolling bearing 1 as shown in FIGS. The vibration measuring device 6a rotates the outer ring 2 by the rotation main shaft 4a while applying a predetermined axial load to the inner ring 3 constituting the rolling bearing 1 by the presser 10. In this state, the vibration acceleration of the inner ring 3 is measured by the detection sensor 11 provided continuously with the presser 10. In the case of the vibration measuring apparatus 6a described in Patent Document 2, the quality of the rolling bearing 1 is determined according to the magnitude of the vibration acceleration measured in this way (vibration acceleration is a predetermined value or more). If there is a defective product) Patent Document 3 describes a technique for measuring vibration of a rolling bearing in a state where the inner ring or outer ring of the rolling bearing is tilted (tilted with respect to the rotation center axis). Patent Document 4 describes a ball bearing inspection device capable of switching the direction of an axial load applied to a race.

By the way, the vibration in the axial direction of the rolling bearing is considered as a vibration model (natural vibration system) with the rolling bearing 1 as a spring as shown in FIG. Can do. In this case, assuming that the axial spring constant of the rolling bearing 1 is K and the mass of the outer ring 2 or the inner ring 3 is M, the natural frequency F in the axial direction of the rolling bearing can be expressed by the following equation (1).
F = 1 / (2π) · √ (K / M) --- (1)
Here, in the state where the axial displacement of the inner ring 3 constituting the rolling bearing 1 is prevented and the axial displacement of the outer ring 2 is allowed (free), the vibration of the outer ring 2 in the axial direction is prevented. When obtaining, the mass M is the mass of the outer ring 2. In this case, the natural frequency F obtained from the expression (1) is the natural frequency in the axial direction of the outer ring mass system. On the other hand, when the vibration of the inner ring 3 is obtained in a state where the displacement of the outer ring 2 in the axial direction is prevented and the displacement of the inner ring 3 in the axial direction is allowed (free), M is the inner ring 3. Mass. In this case, the natural frequency F obtained from the equation (1) is the natural frequency in the axial direction of the inner ring mass system.

  Further, FIG. 10 shows the vibration spectrum of the outer ring mass system of the ball bearing, that is, when the axial vibration of the outer ring is measured in the state where the inner ring constituting the ball bearing is prevented from being displaced in the axial direction. It represents the vibration characteristics of ball bearings. FIG. 3 shows the measurement results of a ball bearing having an identification number 6200 (inner diameter 10 mm, outer diameter 30 mm, width 9 mm). The same result can be obtained even for the case of about 30 mm). As is clear from such a diagram, it can be seen that a clear resonance peak appears at a predetermined frequency (frequency), that is, about 1.5 KHz. The frequency (frequency) of this resonance peak is the natural frequency (resonance frequency) of the outer ring mass system axial direction. Further, in the frequency region higher than the natural frequency (resonance frequency), the vibration spectrum is rapidly attenuated. Therefore, it can be seen that it is difficult to obtain vibration measurement sensitivity (vibration is reduced) in a frequency region higher than the natural frequency (1.5 KHz).

  On the other hand, when evaluating the acoustic performance of a rotating device such as a motor, it is important to measure the vibration (sound) of the rolling bearing in a high frequency region of 4 to 5 KHz. In order to measure vibration in such a high frequency region (to obtain measurement sensitivity), in other words, to vibrate the rolling bearing to such an extent that the vibration characteristics can be sufficiently evaluated, the axial direction of the rolling bearing is not limited. It is preferable to increase the natural frequency F. In order to increase the natural frequency F in this way, it is conceivable to increase the spring constant K or decrease the mass M, as is apparent from the above equation (1). When the spring constant K is increased, it is conceivable to increase the axial load La applied to the rolling bearing. However, if the load La in the axial direction is increased in this way, the load applied to the rolling bearing during actual operation and the load La applied during vibration measurement are greatly shifted, reducing the reliability of the measurement results. There is a possibility of causing damage to the rolling bearing. On the other hand, in order to reduce the mass M, it is conceivable to measure the vibration of the inner ring 3 having a smaller mass than the outer ring 2 (vibration of the inner ring mass system). However, in the case of the prior art described in Patent Documents 1 and 2 described above, there is a possibility that the vibration characteristics cannot be measured accurately even when the vibration of the inner ring 3 is measured in this way.

  That is, when actually measuring the vibration in the axial direction, the mass M in the above formula (1) is the vibration of the bearing ring of the rolling bearing 1 (if the vibration of the inner ring 3 is measured, the vibration of the inner ring and the outer ring 2 is measured. In this case, not only the mass of only the outer ring 2) but also the mass of the entire member (the entire system to be measured) including this race ring (inner ring 3 or outer ring 2) that is displaced (vibrated) with this race ring. For this reason, when the vibration measurement is performed with the technique described in Patent Document 1 described above, that is, with the vibration measuring device 6 shown in FIG. 6, the mass M is not only the mass of the inner ring 3 but also the inner ring 3. This is a value obtained by adding the mass of the shaft 8 to be measured which is a member that is displaced together with the inner ring 3 to the mass. For this reason, the mass M is considerably larger than the mass of the single inner ring 3 alone, and the natural frequency F is accordingly reduced. As the natural frequency F becomes smaller in this way, it becomes difficult to obtain measurement sensitivity in the high frequency region (no vibration). For example, when vibration is measured in the high frequency range of 4 to 5 KHz, the measured value is smaller than the actual vibration amount (vibration amount of the inner ring 3 alone), and the vibration characteristics of the rolling bearing 1 are accurately measured. It may not be possible.

  Further, in the case of the technique described in Patent Document 2 described above, that is, in the case of the vibration measuring device 6a shown in FIGS. 7 to 8, the detection sensor 11 constituted by a piezoelectric conversion element presses the pressing element 10. It attaches to the arm 13 which comprises the pressurizing means 12 for this. For this reason, the free movement of the detector 11 may be hindered. That is, there is a possibility that the detector 11 that should move integrally with the inner ring 3 that is the object to be measured cannot measure the inherent vibration of the inner ring 3 with high accuracy due to the restraint of the arm 13.

Japanese Utility Model Publication No. 56-25245 JP-A-5-126628 JP 2004-361390 A JP 2000-292314 A Akio Igarashi, “Introductory Course, Rolling Bearings 7 Vibration and Acoustics of Rolling Bearings”, Magazine “Lubrication”, Japan Lubrication Society (now Tribology Society), 1971, Vol. 16, No. 4, p. 307 Rolling Bearing Engineering Editorial Committee, “Rolling Bearing Engineering”, first edition, Yokendo Co., Ltd., July 10, 1975, p. 140-142

  The axial direction vibration measuring method and vibration measuring apparatus of the present invention are invented to accurately measure the axial direction vibration characteristics of the rolling bearing in view of the above-described circumstances.

The rolling bearing according to the present invention has a plurality of rolling bearings between the inner ring raceway provided on the outer peripheral surface of the inner ring and the outer ring raceway provided on the inner peripheral surface of the outer ring. The rolling element is provided.
The axial vibration measurement method of the rolling bearing according to claim 1 relates to an elastic member (for example, synthetic resin, etc.) having a smaller (axial) spring constant than the rolling bearing with respect to the rigidity in the axial direction of the rolling bearing. The outer ring is rotated while an axial load is applied to the inner ring via a polymer made of a polymer material such as elastomer such as rubber, or a spring element such as a leaf spring or a coil spring. In this state, the vibration in the axial direction of the inner ring is measured.
This measurement is performed in a state in which the inner ring is prevented from rotating (stationary) and the outer ring is prevented from displacement in the axial direction. The elastic member has, for example, an axial spring constant of a rolling bearing for use in a motor of about 2 N / μm to 20 N / μm, and therefore is smaller than this value, more preferably a sufficiently small value (for example, 1/2 The spring constant is preferably 1/10 or less, more preferably 1/100 or less), for example, 0.02 to 2 N / μm, and more preferably about 0.02 to 1 N / μm.

Further, when the vibration measuring method described in claim 1 is carried out, it is preferable that the member that is displaced (vibrated) together with the inner ring (for example, between the inner ring and the elastic member) as described in claim 2. The vibration in the axial direction of the inner ring is measured by vibration detection means provided integrally with the pressing piece held between the two.
In addition, as described in claim 3, by changing the weight of the member displaced together with the inner ring, the natural frequency (resonant frequency) of the entire member displaced together with the inner ring including the inner ring is set to a desired value. In the adjusted state, the vibration in the axial direction of the inner ring is measured.

  According to a fourth aspect of the present invention, the axial vibration measuring device of the rolling bearing is smaller than the rolling bearing in terms of load applying means for applying an axial load to the inner ring and rigidity in the axial direction of the rolling bearing. An elastic member having a spring constant, vibration detecting means for detecting vibration of the inner ring, and rotation driving means for rotating the outer ring are provided. Then, the outer ring is rotated by the rotation driving unit while an axial load is applied to the inner ring through the elastic member by the load applying unit. At this time, the inner ring is in a state in which rotation is prevented (stationary), and the outer ring is in a state in which displacement in the axial direction is prevented. In this state, the vibration in the axial direction of the inner ring is measured by the vibration detecting means.

Further, when implementing the vibration measuring apparatus according to the fourth aspect, it is preferable that, as described in the fifth aspect, a member that is displaced together with the inner ring (for example, sandwiched between the inner ring and the elastic member). The vibration detecting means is provided integrally with the pressing piece.
Further, as described in claim 6, the weight of the member displaced together with the inner ring can be adjusted to a desired value. In this case, preferably, the vibration in the axial direction of the inner ring is measured in a state where the natural frequency (resonance frequency) of the entire member including the inner ring and displaced with the inner ring is adjusted to a desired value.

According to the axial-direction vibration measuring method and vibration measuring apparatus of the present invention configured as described above, the vibration characteristics in the axial direction of the rolling bearing can be accurately measured.
That is, since the vibration of the inner ring, which is lighter than the outer ring, is measured, the natural frequency (resonance frequency) can be increased as compared with the case of measuring the vibration of the outer ring. Further, only an axial load is applied to the inner ring via an elastic member, and the inner ring is not rotated. For this reason, the member that is displaced (vibrated) together with the inner ring can also be configured to be lighter than the case of the vibration measuring device described in, for example, Patent Document 1 (because it is not necessary to transmit rotation). Can increase the frequency (can approach the natural frequency of the inner ring alone). As the natural frequency can be increased in this way (close to the natural frequency of the inner ring alone), the sensitivity in the high frequency region can be secured (the inner ring can be accurately evaluated even in the high frequency region). For example, the acoustic characteristics in a high frequency region of 4 to 5 KHz can be measured with high accuracy. Moreover, since the elastic member has a small spring constant with respect to the rigidity in the axial direction of the rolling bearing, vibration insulation of the inner ring can be achieved by the elastic member. In other words, the elastic member can allow movement (displacement, vibration) of the inner ring while applying an axial load to the inner ring. For this reason, the inherent vibration of the inner ring can be accurately measured.

Moreover, if the structure described in Claims 2 and 5 is adopted, the mass of the entire member displaced together with the inner ring can be further reduced. Therefore, the natural frequency (resonance frequency) can be further increased (closer to the natural frequency of the inner ring alone), and the vibration characteristics can be measured with high accuracy even in the high frequency region.
Further, if the configuration described in the third and sixth aspects is adopted, a rotating device such as a motor incorporating a rolling bearing is adjusted by adjusting the weight of a member (for example, a pressing piece) that is displaced (vibrated) together with the inner ring. The vibration of the rolling bearing can be measured in a state matched to the natural frequency (resonance frequency) of the bearing. For this reason, even if this rolling bearing is not incorporated in the rotating device, the vibration of the rolling bearing can be accurately measured in the same state as that incorporated in the rotating device.

  1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1, 2, 4, and 5. FIG. A rolling bearing 1 to be measured by the vibration measuring device 6b of this example includes an outer ring 2, an inner ring 3, and a plurality of rolling elements 16,16. The rolling elements 16 and 16 are provided between the inner ring raceway 17 provided on the outer peripheral surface of the inner ring 3 and the outer ring raceway 18 provided on the inner peripheral surface of the outer ring 2 so as to be able to roll. Thus, relative rotation between the outer ring 2 and the inner ring 3 is allowed. The vibration measuring device 6b of this example is for measuring the vibration of the rolling bearing 1 in the axial direction (left-right direction in FIG. 1), and includes a load applying means 19, an elastic member 20, and vibration detection. Means 21 and rotational drive means 22 are provided.

  Of these, the load applying means 19 is for applying a predetermined axial load (a load to be pressed to the right in FIG. 1) to the inner ring 3, and is constituted by a pressing device 23 and a pressing piece 24. . Of these, the pressing device 23 is configured by, for example, a hydraulic actuator, an air actuator, or a spring member such as a compression coil spring or a leaf spring, and generates a predetermined pressing force. The pressing device 23 may be of any type other than the hydraulic type, air pressure (pneumatic) type, and spring pressure type as long as it can apply a predetermined axial load to the inner ring 3. is there. The pressing piece 24 presses the inner ring 3 through the elastic member 20 by the pressing device 23. The elastic member 20 has a spring constant smaller than that of the rolling bearing 1 with respect to the rigidity of the rolling bearing 1 in the axial direction. As those having such characteristics, for example, those made of a polymer material such as synthetic resin and elastomer such as rubber, or spring elements such as leaf springs and coil springs can be employed.

  In the case of this example, the elastic member 20 is cylindrical (ring-shaped). Then, both end edges in the axial direction of such a cylindrical elastic member 20 are in contact with the side surface of the pressing device 23 and the one side surface of the pressing piece 24 over the entire circumference. It is sandwiched between the pressing piece 24. In addition, the elastic member 20 is not only a member that is in contact with both sides of the pressing device 23 and the pressing piece 24 over the entire circumference (cylindrical member), for example, a cylindrical member in the circumferential direction. It can also be configured by arranging a plurality (for example, three).

  The vibration detection means 21 detects the vibration of the inner ring 3 and is constituted by a vibration sensor 25 such as a piezoelectric acceleration sensor (acceleration pickup). In the case of this example, the vibration sensor 25 is provided integrally with the pressing piece 24, and the pressing piece 24 and the vibration sensor 25 vibrate (displace) together with the inner ring 3 during measurement as described later. As described above, the pressing piece 24 and the vibration sensor 25 that are displaced together with the inner ring 3 are light in weight as described above. In addition, the inner ring 3 itself (inner ring 3 alone) measures vibrations. This is preferable in terms of increasing the number and improving the measurement sensitivity in the high frequency region. For this reason, in the case of the present embodiment, the pressing piece 24 is made of a material having a small specific gravity and a high rigidity, such as an aluminum alloy, a titanium alloy, or a ceramic. In the case of the illustrated example, the pressing piece 24 is constituted by a flange portion 26 that contacts the side surface of the inner ring 3 and a fitting portion 27 that fits inside the inner ring 3. However, in order to further reduce the weight of the pressing piece 24, it is possible to omit the fitting portion 27 and use only the flange portion 26.

  Further, the vibration sensor 25 may be a non-contact type sensor such as a laser Doppler type vibration detector instead of a contact type sensor such as a piezoelectric acceleration sensor. If comprised in this way, the mass for the said vibration sensor 25 minutes can also be reduced, and the further weight reduction of the member displaced (vibrated) with the said inner ring | wheel 3 can be achieved. As described above, such weight reduction is preferable in terms of measuring the vibration of the inner ring 3 itself (inner ring 3 alone) and increasing the natural frequency to improve measurement sensitivity in a high frequency region. In any case, the output signal of the vibration sensor 25 is sent to a measurement circuit (not shown) to perform signal processing according to the purpose such as measurement display of vibration amount, pass / fail judgment of vibration level, vibration spectrum analysis, and the like.

  The rotation drive means 22 is for rotating the outer ring 2 and is constituted by a rotation main shaft 28 that is driven to rotate by a drive source such as a motor (not shown). The rotating main shaft 28 is provided with a concave portion 29 for fitting the outer ring 2 into the axial front end portion (left end portion in FIG. 1) without rattling. At the time of vibration measurement, the outer ring 2 is fitted in the recess 29 and rotates at a predetermined rotational speed. In such a measurement, since it is not preferable that the vibration of the rotation main shaft 28 is detected as the vibration of the inner ring 3, the rotation main shaft 28 is assumed to be highly rigid.

  When vibration in the axial direction of the rolling bearing 1 is measured by the vibration measuring device 6b of the present example configured as described above, the outer ring 2 of the rolling bearing 1 is fitted in the recess 29 of the rotating main shaft 28. The pressing piece 24 is abutted against the end face of the inner ring 3. Then, while the inner ring 3 is pressed to the right in FIG. 1 by the pressing device 23 via the elastic member 20 (while an axial load is applied), the rotation of the inner ring 3 is prevented (stationary state). ) To rotate the rotary spindle 28. Then, based on the rotation of the rotating main shaft 28, the outer ring 2 is rotated in a state in which displacement in the axial direction is prevented. In this state, the vibration sensor 25 measures the vibration of the inner ring 3 in the axial direction.

According to the vibration measuring device 6b of this example configured as described above, the vibration characteristics in the axial direction of the rolling bearing 1 can be measured with high accuracy.
That is, as the vibration of the rolling bearing 1, the vibration of the inner ring 3 that is lighter than the outer ring 2 is measured. Therefore, the natural frequency (resonance frequency) is set as compared with the case of measuring the vibration of the outer ring 2. Can be big. Further, only an axial load is applied to the inner ring 3 via the elastic member 20, and the inner ring 3 is not rotated. For this reason, for example, compared to the vibration measuring device 6 (see FIG. 6) as described in Patent Document 1, the member that is displaced (vibrated) together with the inner ring 3 can be configured to be lighter, and the natural frequency can also be seen from this surface. Can be increased (can approach the natural frequency of the single inner ring 3). As the natural frequency can be increased in this way (close to the natural frequency of the single inner ring 3), the sensitivity in the high frequency region can be secured (the inner ring can be accurately evaluated even in the high frequency region). 3 can be vibrated), for example, acoustic characteristics in a high frequency region of 4 to 5 KHz can be measured with high accuracy. In addition, since the elastic member 20 has a small spring constant with respect to the rigidity in the axial direction of the rolling bearing, the elastic member 20 can insulate the inner ring 3 (and the pressing piece 24) from vibration. That is, the elastic member 20 can allow the inner ring 3 (and the pressing piece 24) to move (displace, vibrate) while applying an axial load to the inner ring 3. Further, since the pressing piece 24 is also lightweight, the pressing piece 24 is also displaced (vibrated) integrally with the inner ring 3. Therefore, the vibration of the inner ring 3 can be detected by the vibration sensor 25 provided integrally with the pressing piece 24 without being attenuated or distorted, and the inherent vibration of the inner ring 3 can be accurately measured.

In the case of this example, since the vibration sensor 25 is integrally provided on the pressing piece 24 that is a member that is displaced together with the inner ring 3 as described above, the mass of the member that is displaced together with the inner ring 3 can be further reduced. Therefore, the natural frequency (resonance frequency) can be further increased (closer to the natural frequency of the single inner ring 3), and the vibration characteristics can be measured with high accuracy even in the high frequency region.
FIG. 2 shows the result (vibration spectrum) of the vibration measurement of the ball bearing (inner diameter: 10 mm, outer diameter: 30 mm, width: 9 mm) of the reference number 6200 with the vibration measuring device 6b of this example. As apparent from comparing the diagram of FIG. 2 with the diagram of FIG. 10 described above, according to the vibration measuring apparatus 6b of this example, the natural frequency (resonance frequency) can be increased by about 50%. . In addition, for vibration (acoustic) up to about 5 KHz, which is important in evaluating the acoustic performance of a rotating device such as a motor, for example, a comparison was made between a frequency region higher than the resonance frequency and a flat characteristic portion below this resonance frequency. In this case, in the case of the conventional measuring apparatus, the high-frequency region is reduced by about 20 dB compared to the flat portion, but in the case of this example, the reduction is only about 10 dB.

  FIG. 3 shows a second example of an embodiment of the present invention corresponding to claims 1 to 6. In the case of this example, the weight of the pressing piece 24a, which is a member that is displaced together with the inner ring 3 (see FIG. 1), can be adjusted to a desired value. Therefore, in the case of the present embodiment, the weight 30 can be attached to and detached from the distal end portion (the right end portion in FIG. 3) of the fitting portion 27 of the pressing piece 24a. The weight 30 is made of a material having a large specific gravity, such as a lead alloy, and is coupled and fixed to the distal end portion of the fitting portion 27 by screwing, adhesion, pressure bonding, or the like. In this way, by making the weight of the pressing piece 24a variable, the natural frequency of the entire member (the pressing piece 24a and the vibration sensor 25) including the inner ring 3 and displaced (vibrates) together with the inner ring 3 is desired. The vibration in the axial direction of the inner ring 3 is measured in a state adjusted to this value.

In the case of this example, by adjusting the weight of the pressing piece 24a which is a member that is displaced together with the inner ring 3, for example, the natural vibration of a rotating device such as a motor incorporating the rolling bearing 1 (see FIG. 1). The vibration of the rolling bearing 1 (inner ring 3) can be measured in a state matched to the number (resonance frequency). For this reason, even if this rolling bearing 1 is not incorporated in the rotating device, the vibration of the rolling bearing 1 can be measured with high accuracy in the same state as that incorporated in the rotating device.
Other configurations and operations are the same as those in the first example described above, and thus overlapping illustrations and descriptions are omitted.

Sectional drawing which shows the 1st example of embodiment of this invention. The diagram which shows the result of having measured the vibration of the axial direction of a ball bearing with the apparatus shown in FIG. The principal part front view which shows the 2nd example of embodiment of this invention. The front view which shows the measuring apparatus for measuring the vibration of the radial direction of the conventional rolling bearing. The figure seen from the left of FIG. Sectional drawing which shows the 1st example of the measuring apparatus for measuring the vibration of the axial direction of the conventional rolling bearing. The front view which shows the 2nd example. The expanded sectional view equivalent to the A section of Drawing 7 at the time of measurement. The vibration model figure for demonstrating the vibration characteristic of the axial direction of a rolling bearing. The diagram which shows the result of having measured the vibration of the axial direction of the ball bearing with the conventional measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Outer ring 3 Inner ring 4, 4a Rotation main shaft 5 Vibration pick-up 6, 6a, 6b Vibration measuring device 7 Hollow rotation main shaft 8 Measuring shaft 9 Elastic member 10 Presser 11 Detection sensor 12 Pressurizing means 13 Arm 14 Endless belt 15 Detector 16 Rolling element 17 Inner ring raceway 18 Outer ring raceway 19 Load applying means 20 Elastic member 21 Vibration detecting means 22 Rotating drive means 23 Pressing device 24, 24a Pressing piece 25 Vibration sensor 26 Flange part 27 Fitting part 28 Rotating spindle 29 Concave part 30 Weight

Claims (6)

  An axial vibration measurement method for a rolling bearing comprising a plurality of rolling elements between an inner ring raceway provided on an outer peripheral surface of an inner ring and an outer ring raceway provided on an inner peripheral surface of an outer ring, comprising: With regard to the rigidity in the axial direction, the vibration in the axial direction of the inner ring is measured while the outer ring is rotated while applying an axial load to the inner ring through an elastic member having a smaller spring constant than that of the rolling bearing. A method for measuring vibration in the axial direction of a rolling bearing, characterized by:   2. The method of measuring axial vibration of a rolling bearing according to claim 1, wherein vibration in the axial direction of the inner ring is measured by vibration detecting means provided integrally with a member that is displaced together with the inner ring.   By changing the weight of the member displaced with the inner ring, the vibration in the axial direction of the inner ring is measured in a state where the natural frequency of the entire member including the inner ring and the member displaced with the inner ring is adjusted to a desired value. A method for measuring vibration in the axial direction of the rolling bearing according to claim 1.   An axial vibration measuring device for a rolling bearing comprising a plurality of rolling elements provided between an inner ring raceway provided on an outer peripheral surface of an inner ring and an outer ring raceway provided on an inner peripheral surface of an outer ring. A load applying means for applying a load; an elastic member having a spring constant smaller than that of the rolling bearing with respect to the rigidity in the axial direction of the rolling bearing; a vibration detecting means for detecting vibration of the inner ring; A rotation driving means for rotating the outer ring, the axial force is applied to the inner ring via the elastic member by the load applying means, and the outer ring is rotated by the rotation driving means. An axial vibration measurement apparatus for a rolling bearing, characterized by measuring the axial vibration of the inner ring by a detecting means.   The apparatus for measuring vibration in the axial direction of a rolling bearing according to claim 4, wherein a vibration detecting means is integrally provided on a member that is displaced together with the inner ring.   6. The vibration measuring apparatus in the axial direction of a rolling bearing according to claim 4, wherein the weight of the member displaced together with the inner ring can be adjusted to a desired value. 7.

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