JPH08200358A - Preloaded radial ball bearing and method of manufacturing the same - Google Patents

Abstract

PURPOSE: To apply a proper pre-load to balls without using parts troublesome for machining. CONSTITUTION: A pair of auxiliary rings 15, 15 are outwardly coupled on the outer periphery of a shaft 14, and an inner ring raceway track 2b is formed across both auxiliary rings 15, 15. When the interval between both auxiliary rings 15, 15 is narrowed after balls 7, 7 are fitted, a proper pre-load is applied to the balls 7, 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A radial ball bearing to which a preload is applied and a method of manufacturing the same according to the present invention are applicable to, for example, a linear carriage roller of a hard disk drive (HDD), a spindle motor, or a video tape recorder (VTR).
The present invention relates to radial ball bearings that support rotating parts by incorporating them into various thin motors such as pinch rollers and various precision rotating parts.

[0002]

2. Description of the Related Art Radial ball bearings are used to support spindles of VTRs and HDDs. The radial ball bearings used for such precision rotating parts have whirling motions (motions in the direction perpendicular to the axis). Also, it is necessary to apply a predetermined preload to prevent axial runout. In order to apply a preload to the radial ball bearings, a pair of radial ball bearings that are independent of each other are generally used, and the inner ring or the outer ring of the pair of radial ball bearings is pressed to the opposite side in the axial direction. In addition, a structure for applying a preload to a single radial ball bearing is also known, for example
It is conventionally known as described in JP-A-116016 and JP-A-6-173957.

First, FIG. 14 shows an actual flat plate 4-116016.
The structure described in the publication is shown. The shaft 1 functions as an inner ring. A deep groove type inner ring raceway 2 is formed on the outer peripheral surface of the shaft 1. The outer ring 3 is a pair of outer ring elements 4
It is configured by connecting and fixing a and 4b. Conical concave surfaces 5 are formed on the inner peripheral surfaces of the outer ring elements 4a and 4b, respectively.
a and 5b are formed so as to face each other. The conical concave surfaces 5a and 5b are formed on the outer ring elements 4a and 4b.
The V-groove-shaped outer ring raceway 6 is formed in the state of being connected to each other. A plurality of balls 7, 7 are rollably mounted between the outer ring raceway 6 and the inner ring raceway 2. In the case of such a structure,
If the shapes and sizes of the outer ring elements 4a and 4b are properly regulated, a preload can be applied to the balls 7 and 7.

Next, FIG. 15 is a schematic view of Japanese Patent Laid-Open No. 6-173957.
The structure described in the publication is shown. On the outer peripheral surface of the inner ring 8, an inner ring raceway 2a having a trapezoidal cross section is formed.
The outer ring 3a is composed of an outer ring body 9 and an auxiliary wheel 10.
A male screw 11 is formed on the outer peripheral surface of the auxiliary wheel 10, and the male screw 11 is formed on the inner peripheral surface of the outer ring main body 9.
The outer ring body 9 and the auxiliary wheel 10 are coupled to each other by screwing the outer ring 3 into the outer ring 3a. An outer ring raceway 6a having a trapezoidal cross section is formed on the inner peripheral surface of the outer ring 3a. A plurality of balls 7, 7 rotatably held by a cage 13 are provided between the outer ring raceway 6a and the inner ring raceway 2a. In the case of such a structure, a preload can be applied to the balls 7, 7 by adjusting the axial position of the auxiliary wheel 10 with respect to the outer ring body 9 based on the screw engagement of the male screw 11 and the female screw 12.

[0005]

In the case of the conventional preloaded radial ball bearing configured as described above, the manufacturing of the constituent members is troublesome, and the preloaded radial ball bearing is not manufactured. It is difficult not only to increase the manufacturing cost but also to give the balls 7, 7 an accurate preload as desired.

First, in the case of the structure of the first conventional example shown in FIG. 14, since the preload applied to the balls 7, 7 is determined by the size and shape of the outer ring elements 4a, 4b, an appropriate preload is applied. In order to achieve this, the outer dimensions of the outer ring elements 4a and 4b must be finished extremely accurately. It is not preferable to finish the outer ring elements 4a and 4b having a complicated shape with high precision because the manufacturing cost of the outer ring elements 4a and 4b is increased. Incidentally, these outer ring elements 4a, 4
If the preload applied to each of the balls 7, 7 due to the dimensional error of b is insufficient, whirling motion and axial wobbling are likely to occur in the rotary support portion incorporating the radial ball bearing. On the other hand, if the preload becomes excessive, the resistance of the rotation supporting portion becomes large, which causes problems such as increased energy loss and heat generation.

Further, in the case of the structure of the second example shown in FIG. 15, it is necessary to form an internal thread 12 on the inner peripheral surface of the outer ring main body 9 or an external thread 11 on the outer peripheral surface of the auxiliary wheel 10. .
The work of forming a screw on a component of a small radial ball bearing, such as being incorporated in a rotation supporting portion of an HDD or a VTR, is troublesome and also causes a high manufacturing cost. Further, the work of screwing the small-diameter female screw 12 and the male screw 11 together and further tightening them to give a preload is troublesome, and the assembling work becomes troublesome, which causes a rise in manufacturing cost.

Further, in any structure, in order to maintain the applied preload, it is necessary to bond the two parts constituting the outer rings 3, 3a to each other. Such a bonding work is troublesome and also causes a high manufacturing cost. JP-A-6-34423
Although Japanese Patent Publication No. 3 discloses a structure and method for applying an appropriate preload to a double row radial ball bearing, it does not consider applying a single preload to a single row radial ball bearing. The preloaded radial ball bearing and the manufacturing method thereof according to the present invention have been invented in view of such circumstances.

[0009]

Of the radial preloaded radial ball bearings and the manufacturing method thereof according to the present invention, the invention of the preloaded radial ball bearing according to claim 1 is the first circumferential surface. Formed on the first peripheral surface and a second member having a second peripheral surface that is arranged concentrically with the first peripheral surface and that faces the first peripheral surface. Deep groove type first orbit, a deep groove type second orbit formed in a portion of the second peripheral surface facing the first orbit, the second orbit and the first And a plurality of balls rotatably provided between the plurality of balls, and a preload is applied to the plurality of balls between the first track and the second track.

In particular, in the preloaded radial ball bearing of the present invention, at least one auxiliary wheel is provided in the first member in the axial direction larger than the axial load due to the preload. It is mated and fixed with mating strength that exerts force,
The peripheral surface of the auxiliary wheel constitutes a part of the first peripheral surface, and at least one half of the first track is formed on the peripheral surface of the auxiliary wheel.

According to the invention of the method for manufacturing a preloaded radial ball bearing described in claim 2, the preloaded radial ball bearing according to claim 1 is manufactured.
The distance between at least one half of the first orbit and the other half of the first orbit formed on a part of the first circumferential surface of the auxiliary wheel is Insert the plurality of balls between the first track and the second track in a state of being larger than the interval required to apply preload, and evenly distribute the balls in the circumferential direction. After the disposition, the auxiliary wheel is axially moved with respect to the first member, so that the distance between the one half and the other half of the first track is set to a length required for preloading.

[0012]

According to the preloaded radial ball bearing of the present invention and the method of manufacturing the same as described above, a single-row radial ball bearing can be obtained without requiring particularly complicated parts or troublesome machining. Preload can be applied. Further, since complicated work such as screwing work and bonding work of fine screws is unnecessary, it is possible to contribute to the efficiency of the assembly work.

[0013]

FIG. 1 shows a first embodiment of the present invention. On the outer peripheral surface, which is the first peripheral surface, of the shaft 14, which is the first member, the pair of auxiliary wheels 15, 15 have sufficient fitting strength, that is, the reaction force of the preload applied to the balls 7, 7. Based on each auxiliary wheel 15,
It is externally fitted and fixed with a fitting strength that generates a holding force larger than the axial force applied to 15. These pair of auxiliary wheels 1
The end faces 5 and 15 facing each other are not brought into contact with each other, and a gap 1 having a width dimension of δ ₀ is provided between these end faces.
6 is interposed. The inner ring raceway 2b, which is the first raceway, is provided on a part of the outer peripheral surfaces of the auxiliary wheels 15 and 15 which are also the first peripheral surface.
It is formed by straddling between 15 members.

Further, around the both auxiliary wheels 15 and 15,
The outer ring 3b which is the second member is attached to the shaft 14 and the auxiliary wheel 1.
It is arranged concentrically with 5 and 15. A second groove, a deep groove type outer ring raceway 6b, is formed on the inner peripheral surface of the outer ring 3b, which is the second circumferential surface. And this outer ring track 6
A plurality of balls 7, 7 rotatably held by a cage 13a are provided between b and the inner ring raceway 2b. still,
The shield plates 17, 17 are provided on the inner peripheral surfaces of both ends of the outer ring 3b.
Of the shield plates 17 and 17 are brought close to the outer peripheral surfaces of the end portions of the auxiliary wheels 15 and 15 to seal the ball 7 and 7 installation portions.

According to the structure of the present invention configured as described above, the pitch between the pair of auxiliary wheels 15 and 15 is adjusted while changing the width dimension δ ₀ of the gap 16 to adjust each ball 7 By changing the contact position between the rolling surfaces of the balls 7 and 7 and the inner ring raceway 2b, the preload applied to the balls 7 can be adjusted. Next, a manufacturing method for realizing the structure as shown in FIG. 1 will be described with reference to FIGS.

First, as shown in FIG. 2, simple cylindrical auxiliary wheel elements 18, 18 on which the inner ring raceway 2b is not yet formed are externally fitted and fixed to the shaft 14. At this time, the width dimension δ ₁ of the gap 16a existing between the end faces of the auxiliary wheel elements 18, 18 is the width dimension δ ₀ of the gap 16 between the end faces of the auxiliary wheels 15, 15 at the time of completion. Larger than (Fig. 1) (δ
₁ > δ ₀ ).

When the pair of auxiliary wheel elements 18, 18 are externally fitted and fixed on the outer peripheral surface of the shaft 14 in this way, as shown in FIG. An inner ring raceway 2b is formed on a part of the outer peripheral surfaces of the elements 18, 18 so as to bridge the both auxiliary wheel elements 18, 18. Thus, after the auxiliary wheel elements 18, 18 are externally fitted to the shaft 14, the inner ring raceways 2b are formed on both auxiliary wheel elements 18, 18, so that the auxiliary wheels 15, 15 (FIG. 1, 3, 4, 5) is fitted onto the shaft 14, the shape accuracy and dimensional accuracy of the inner ring raceway 2b are improved. That is,
The auxiliary wheels 15 and 15 having the inner ring raceway 2b formed in advance are attached to the shaft 14
When the outer ring is fitted to the inner ring raceway 2b, the shape accuracy and dimensional accuracy of the outer peripheral surface of the shaft 14 affect the accuracy of the inner ring raceway 2b. On the other hand, as in the illustrated embodiment, the auxiliary wheel elements 18, 18 are attached to the shaft 1
When the inner ring raceway 2b is formed after the outer ring is fitted on the outer ring 4, the shape accuracy and the dimensional accuracy of the outer peripheral surface of the shaft 14 do not affect the accuracy of the inner ring raceway 2b, and the shape accuracy and the dimensional accuracy of the inner ring raceway 2b are increased.

In this way, the auxiliary wheel 1 is provided on the outer peripheral surface of the shaft 14 with each half of the inner ring raceway 2b on each outer peripheral surface.
When the outer ring 5 and the outer ring 15 are fitted, the shaft 14 and the auxiliary wheels 15 and 15 are inserted inside the outer ring 3b having a cylindrical shape, as shown in FIG. Then, a plurality of balls 7, 7 are inserted between the outer ring raceway 6b formed on the inner peripheral surface of the outer ring 3b and the inner ring raceway 2b. In this work, the shaft 14 and the auxiliary wheels 15, 15 and the outer ring 3b are eccentric, and the outer ring raceway 6b is moved.
The width dimension in the diametrical direction (vertical direction in FIG. 4) of the gap 19 extending in the circumferential direction between the inner ring raceway 2b and the inner ring raceway 2b is partially increased, and the gap 19 extends from the portion having the increased width dimension into the gap 19. , By inserting a predetermined number of balls 7, 7.

When a predetermined number of balls 7, 7 are inserted into the gap 19 in this manner, the shaft 14 and the auxiliary wheel 15 are moved while moving the predetermined number of balls 7, 7 in the circumferential direction. ,
The balls 15 and the outer ring 3b are concentric with each other and the balls 7, 7 are arranged at equal intervals in the circumferential direction. Along with this, retain each ball 7, 7 in the cage 1.
3a so that the balls 7, 7 stay at positions at equal intervals in the circumferential direction. Further, the shield plates 17, 17 are attached to the inner peripheral surfaces of both ends of the outer ring 3b. In this state, each ball is still 7,
No preload was applied to 7. Therefore, each of these balls 7,
When moving 7 in the circumferential direction, the rolling surfaces of the balls 7, 7 and the inner ring raceway 2b and the outer ring raceway 6b will not be scratched or otherwise damaged.

Finally, the pair of auxiliary wheels 15 and 1
By axially displacing one or both of 5 with respect to the shaft 14, the pair of auxiliary wheels 15, 15 are brought closer to each other, and a preload is applied to the balls 7, 7. In this state, the width dimension of the gap 16 between the end faces of the auxiliary wheels 15 and 15 is δ ₀ (FIG. 1). In this way, a pair of auxiliary wheels 1
The operation of bringing the balls 5 and 15 closer to each other and adjusting the preload of the balls 7 and 7 to a predetermined value is performed by using a device as shown in FIG.

The components of the single-row radial ball bearing are shown in FIG.
When assembled to the state shown in Fig. 5, one end of the shaft 14 (the lower end of Fig. 5) is inserted into the circular hole 21 formed in the holder 20, and the end face of the holder 20 is moved to one side (Fig. 5).
A lower end) of the auxiliary wheel 15. A pressing piece 23 is attached to the other end (upper end in FIG. 5) of the shaft 14. Then, by the pushing device 22, these holders 2
By narrowing the distance between 0 and the pressing piece 23, the one auxiliary wheel 15 is pushed into the shaft 14 and the pair of auxiliary wheels 1
Pre-load is applied to each of the balls 7, 7 by narrowing the interval between the balls 5, 15.

Between the holder 20 and the base plate 24, and between the pressing piece 23 and the pushing device 22, the pushing arm 2 is provided.
Piezoelectric elements 26a and 26b are sandwiched between the piezoelectric elements 5 and 5, respectively. Each of the piezoelectric elements 26a and 26b has sufficient rigidity in the pushing direction of the auxiliary wheel 15 (vertical direction in FIG. 5). In addition, these piezoelectric elements 26a, 26
b is, in accordance with the signal sent from the signal generator 27,
Driven by amplifier 28.

For example, the signal generator 27 outputs a signal for detecting the resonance frequency of the radial ball bearing, as well as a signal for pushing the auxiliary wheel 15 into the shaft 14, that is, a signal for reducing the stick slip. . The pair of piezoelectric elements 26a and 26b are driven with opposite phases and the same amplitude. That is, when one piezoelectric element 26a is expanded, the other piezoelectric element 26b is contracted by the same amount. This is because the auxiliary wheel 15 causes the shaft 14 to move in accordance with the vibration of the rolling bearing device by the piezoelectric elements 26a and 26b.
This is to prevent the shaft 14 and the auxiliary wheel 15 from vibrating sufficiently in the axial direction by preventing the shaft 14 and the auxiliary wheel 15 from being pushed into (the pressing work is performed by the piezoelectric elements 26a and 26b extending at the same time). On the other hand, a stylus of a vibration sensor 29 is abutted against the end surface of the outer ring 3b, and the output of the vibration sensor 29 is input to the controller 31 via the FFT converter 30. The controller 31 controls the pushing arm 25 by the pushing device 22.
Regulate the amount of displacement.

When manufacturing the radial ball bearing to which a preload is applied, when the auxiliary wheel 15 is pushed into the shaft 14 to apply an appropriate preload to the balls 7 and 7, the radial ball is detected by the vibration sensor 29. While measuring the resonance frequency of the bearing, pressure oil is fed to the pushing device 22 to hold the holder 2
The auxiliary wheel 15 is displaced with respect to the shaft 14 by pressing the shaft 14 with the pushing arm 25 while holding the end surface of the auxiliary wheel 15 by 0. Then, when the resonance frequency substantially matches the preset frequency, the feeding of the pressure oil into the pushing device 22 is stopped, and the press-fitting operation is completed. In this state, a single row radial ball bearing to which an appropriate preload is applied is completed. The resonance frequency when an appropriate preload is applied to the radial ball bearing can be obtained by measuring the resonance frequency of the radial ball bearing to which an appropriate preload is applied by a separately known method. Since this work needs to be performed only once, it is performed by a method that can obtain an accurate measurement value even if it is troublesome, such as repeating trial and error.

If the rolling bearing is efficiently vibrated by the pair of piezoelectric elements 26a and 26b as in the illustrated embodiment, the resonance frequency can be reliably detected with a small amount of vibration energy. Further, the pair of piezoelectric elements 26a, 2
Since the vibration for reducing the stick slip is also applied to the rolling bearing device by 6b, the auxiliary wheel 15
The force required to push in is stable. It should be noted that such vibration for reducing the stick slip may be applied only to the piezoelectric element 26b between the pressing piece 23 and the pushing arm 25.

Incidentally, in order to regulate the amount of press-fitting of the auxiliary wheel 15 into the shaft 14, a method as shown in FIG. 5 and the application of this method as a reference are described in the above-mentioned JP-A-6-344233. Also, other methods as shown in the following items can be adopted.

The vibration sensor for detecting the vibration of the rolling bearing device is omitted, and an impedance detector for detecting the impedance of the signal sent from the amplifier to each piezoelectric element is provided instead. When the auxiliary wheel is pushed into the shaft, a signal for detecting the resonance frequency and a signal for reducing the stick slip are output from the signal generator, and the pushing operation is performed while vibrating the piezoelectric elements in accordance with the both signals. When the resonance frequency of the rolling bearing device changes as the pushing operation progresses, the impedance of the signal changes.
Therefore, with this impedance reaching a predetermined value,
Stop pushing the auxiliary wheel by the pushing device.

When pushing the auxiliary wheel, the vibration of the rolling bearing device is measured by a laser Doppler vibrometer.
Non-contact detection is possible. The vibration of the rolling bearing device detected by the laser Doppler vibrometer is sent to the controller via the FFT converter to control the pushing device for pushing the auxiliary wheel.

A signal for detecting the resonance frequency of the rolling bearing device and a signal for reducing the stick slip are added only to the piezoelectric element between the pressing piece and the pushing arm, and the vibration of the rolling bearing device is detected by the other piezoelectric element. To do. The detected value of the other piezoelectric element is passed through an amplifier and an FFT converter,
Input to the controller.

A pair of piezoelectric elements is provided between the substrate and the holder, and between the pressing piece and the pushing arm, respectively.
Hold a total of 2 pairs. Of these 2 to 4 piezoelectric elements, one in each pair, two piezoelectric elements in total vibrate in the axial direction based on the energization, and the other two piezoelectric elements vibrate in the direction perpendicular to the axis. Then, a signal for reducing stick-slip is applied from the signal generator to the two piezoelectric elements that vibrate in the axial direction through the amplifier, and the two piezoelectric elements that vibrate in the perpendicular direction pass through the amplifier from the signal generator. Then, a signal for detecting the resonance frequency is added.

Next, FIGS. 6 to 7 show a second embodiment of the preloaded radial ball bearing according to the present invention. In the case of this embodiment, the outer ring raceway 6 formed on the inner peripheral surface of the outer ring 3c.
The cross-sectional shape of c is not a single circular arc but a compound curved surface whose center of the radius of curvature changes midway. The rolling surfaces of the balls 7, 7 and the outer ring raceway 6c are brought into contact with each other at two places. In the case of the radial ball bearing to which the preload is applied according to the present invention, the rolling surfaces of the balls 7 and the inner ring raceway 2b inevitably come into contact with each other at two places. Therefore, in the case of the present embodiment, a rolling bearing of each of the balls 7, 7 is a so-called four-point contact ball bearing in which the inner ring raceway 2b and the outer ring raceway 6c contact each other at two places, that is, four places in total. . Other configurations and manufacturing methods are similar to those of the above-described first embodiment.

Next, FIG. 8 shows a third embodiment of the present invention. In the case of this embodiment, the shaft 14a which is the first peripheral surface
The outer peripheral surface of is composed of a large-diameter portion 32 and a small-diameter portion 33, and the auxiliary wheel 15 forming one half of the inner ring raceway 2b is externally fitted to the small-diameter portion 33 of these. The other half of the inner ring raceway 2b is formed at the end of the large diameter portion 32. In the case of the present embodiment, the auxiliary wheel 15 is axially displaced with respect to the small diameter portion 33, so that the balls 7, 7 are given a necessary preload. Other configurations and manufacturing methods are similar to those of the second embodiment described above.

Next, FIG. 9 shows a fourth embodiment of the present invention. In this embodiment, the outer ring 3d is the first member and the inner ring 8a is the second member. Then, a pair of auxiliary wheels 15a, 15a are fitted in the holding cylinder 34, and an outer ring track 6d is formed on the inner peripheral surface of each of the auxiliary wheels 15a, 15a which is the first peripheral surface. In the case of the present embodiment, the preload is applied to the plurality of balls 7, 7 by changing the distance between the auxiliary wheels 15a, 15a. Further, the inner ring raceway 2c on the outer peripheral surface of the inner ring 8a is adapted to come into contact with the rolling surfaces of the balls 7, 7 at two points each by changing the curvature in the middle. Other configurations and manufacturing methods are the same as those in the first embodiment described above.

Next, FIGS. 10 to 13 show a fifth embodiment of the present invention. In this embodiment, the present invention is applied to a so-called full ball bearing in which a cage is not provided to increase the number of balls 7, 7. To assemble the structure of this embodiment, balls 7 and 7
Even if the auxiliary wheels 15 and 15 and the outer ring 3b are eccentric during the insertion work, all the balls 7 and 7 cannot be inserted. Therefore, the insertion work of the balls 7 and 7 is performed as follows. First, as shown in FIGS. 2 to 3, a pair of auxiliary wheels 15 and 15 fitted onto the shaft 14 are provided.
The inner ring raceway 2b is formed in the
A groove 35 is formed on the outer peripheral surface of the end portion of the auxiliary wheel 15 (on the right side of 2 and 13).
To form. Then, by locking the tool in the groove 35, the one auxiliary wheel 15 is moved away from the other auxiliary wheel 15 (the left side of FIGS. 10, 12, and 13) as shown in FIG. Then, as shown in FIG. 13, the other auxiliary wheel 15 is
The outer ring 3b is positioned around the
A plurality of balls 7, 7 are inserted between 5 and the outer ring 3b. Next, the one auxiliary wheel 15 is replaced with the other auxiliary wheel 15,
After bringing the balls 7 and 7 close to each other so as not to fall off, a preload is applied to the balls 7 and 7 by a method as shown in FIG. 5, for example. The assembling method in which the recessed groove 35 is formed to widen the distance between the pair of auxiliary wheels 15 and 15 at one time is not limited to this embodiment, but can be applied to each of the above-described embodiments.

[0035]

As described above, the preloaded radial ball bearing and the manufacturing method thereof according to the present invention are constructed and operate as described above. Therefore, it is easy to manufacture each component member and the preloaded radial ball bearing is manufactured. There is no increase in manufacturing cost, and it is possible to apply an accurate preload to the ball as desired. As a result, a high-performance preloaded radial ball bearing that does not generate vibration during operation can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing an initial step in manufacturing the structure of the first embodiment.

FIG. 3 is a sectional view showing a step that follows.

FIG. 4 is a sectional view showing the next step also.

FIG. 5 is a sectional view showing a final step of the same.

FIG. 6 is a sectional view showing a second embodiment of the present invention.

FIG. 7 is an enlarged view of part A in FIG.

FIG. 8 is a sectional view showing a third embodiment of the present invention.

FIG. 9 is a sectional view showing the fourth embodiment.

FIG. 10 is a sectional view showing the fifth embodiment.

11 is a view seen from the side of FIG. 10 with the shield plate omitted.

FIG. 12 is a sectional view showing an intermediate step in manufacturing the structure of the fifth embodiment.

FIG. 13 is a sectional view showing a step that follows.

FIG. 14 is a sectional view showing a first example of a conventional structure.

FIG. 15 is a sectional view showing the second example.

[Explanation of symbols]

 1 shaft 2, 2a, 2b, 2c inner ring raceway 3, 3a, 3b, 3c, 3d outer ring 4a, 4b outer ring element 5a, 5b conical concave surface 6, 6a, 6b, 6c, 6d outer ring raceway 7 ball 8, 8a inner ring 9 outer ring Main body 10 Auxiliary wheel 11 Male screw 12 Female screw 13, 13a Cage 14, 14a Shaft 15, 15a Auxiliary wheel 16, 16a Gap 17 Shield plate 18 Auxiliary wheel element 19 Gap 20 Holder 21 Circular hole 22 Pushing device 23 Pressing piece 24 Substrate 25 Pushing arm 26a, 26b Piezoelectric element 27 Signal generator 28 Amplifier 29 Vibration sensor 30 FFT converter 31 Controller 32 Large diameter part 33 Small diameter part 34 Holding tube 35 Recessed groove

Claims (2)

[Claims] 1. A first member having a first peripheral surface, and a second member arranged concentrically with the first member and having a second peripheral surface facing the first peripheral surface. , A deep groove type first orbit formed on the first peripheral surface, and a deep groove type second orbit formed on a portion of the second peripheral surface facing the first orbit. , Comprising a plurality of balls rollably provided between the second track and the first track, the plurality of balls between the first track and the second track In a preloaded radial ball bearing formed by applying a preload, at least one auxiliary wheel in the first member exerts an axial holding force larger than an axial load based on the preload. The auxiliary wheel is fitted and fixed with a fitting strength to form a part of the first peripheral surface, and at least one half of the first track is A preloaded radial ball bearing characterized in that it is formed on the peripheral surface of this auxiliary wheel. 2. A first member having a first peripheral surface, and a second member arranged concentrically with the first peripheral surface and having a second peripheral surface facing the first peripheral surface. , A deep groove type first orbit formed on the first peripheral surface, and a deep groove type second orbit formed on a portion of the second peripheral surface facing the first orbit. , Comprising a plurality of balls rollably provided between the second track and the first track, the plurality of balls between the first track and the second track In a method for manufacturing a preloaded radial ball bearing, which comprises applying a preload, at least one auxiliary wheel is provided on the first member,
Formed on a part of the first peripheral surface that constitutes the peripheral surface of the auxiliary wheel, which is fitted and fixed with a fitting strength that exerts a holding force in the axial direction larger than the axial load based on the preload. With the distance between at least one half of the first track and the other half of the first track set larger than the interval required to apply preload to the ball, the first track and By inserting the plurality of balls between the second track and evenly arranging the plurality of balls in the circumferential direction, by pushing the auxiliary wheel axially with respect to the first member A method for manufacturing a radial ball bearing to which a preload is applied so that a distance between one half and the other half of the first orbit is set to a length required to apply the preload.