JP4078724B2 - Rolling bearing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a rolling bearing device used for a portion that swings at a high speed, such as a bearing for a swing arm for a magnetic disk device.
[0002]
[Prior art]
For example, in a conventional swing arm bearing device, as shown in Japanese Patent Application Laid-Open No. 8-184322, a thin portion is provided on the outer diameter surface of the shaft to which the bearing fits and the inner diameter surface of the housing, and an adhesive is applied to the thin portion. It is applied and fixed by adhesion.
[0003]
[Problems to be solved by the invention]
Recently, the magnetic disk device is required to have higher density, and in order to improve the control band of positioning, it is necessary to improve the main resonance due to the rigidity of the ball bearing. That is, in order to increase the rigidity of the ball bearing, conventionally, it has been necessary to press-fit or bond using a bearing having a specification whose internal specification is changed (groove R is small). For this reason, there was a problem of high cost of newly manufacturing a bearing having a different specification.
[0004]
Therefore, an object of the present invention is to provide a rolling bearing device for a swing arm that can be highly rigid without changing the internal specifications of the rolling bearing and that is low in cost.
[0005]
[Means for Solving the Problems]
In the swing arm rolling bearing device of the present invention, the bearing ring of the rolling bearing is press-fitted and fixed to the shaft member and the other member, respectively, and the axial length of at least one fitting portion of the bearing ring is determined as the raceway surface of the bearing ring. The length of the rolling bearing is less than half the width of the rolling bearing on the contact side of the rolling element.
[0006]
According to the present invention, when a rolling bearing is press-fitted into, for example, a housing, the outer ring or the inner ring is deformed by an interference force acting on the outer ring or the inner ring by shortening the axial length of the press-fitting portion. As a result, the groove R on the raceway surface is reduced, so that high rigidity can be achieved. Further, since the inner ring and the outer ring of the rolling bearing are press-fitted and fixed to the shaft member and the housing, respectively, it is not necessary to use an adhesive. Therefore, the problem of contamination of the magnetic disk surface due to the adhesive outgas is eliminated.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the rolling bearing device for swing arm according to the present invention, in the rolling bearing in which the inner ring is press-fitted and the outer ring is press-fitted and fixed to the housing, the outer diameter press-fitting portion of the outer ring is only on the contact side between the raceway and the rolling element. The axial length of the press-fitted portion is set to a length equal to or less than half the width of the rolling bearing. Thereby, the outer ring is deformed by the interference force acting on the outer ring by press-fitting, the groove R on the raceway surface of the outer ring is reduced, and the swing arm rolling bearing device can have high rigidity.
[0008]
In another embodiment of the swing arm rolling bearing device according to the present invention, in a rolling bearing in which the inner ring is press-fitted and the outer ring is press-fitted and fixed to the housing, the inner ring is press-fitted between the raceway surface and the rolling element. It is provided only on the contact side, and the axial length of the press-fitted portion is set to be half or less the width of the rolling bearing. As a result, the inner ring is deformed by the interference force acting on the inner ring by press-fitting, the groove R on the raceway surface of the inner ring is reduced, and the swing arm rolling bearing device can be made highly rigid.
[0009]
【Example】
Next, the apparatus in the present invention will be specifically described.
FIG. 1 is a sectional view showing a first embodiment of a rolling bearing device for a swing arm according to the present invention.
The swing arm rolling bearing device 1 includes a ball bearing 2, a shaft member 3, and a housing 4. The bearing rings of the ball bearing 2, that is, the inner ring 5 and the outer ring 6 are press-fitted and fixed to the shaft member 3 and the housing 4, respectively. The interference at the time of press-fitting is preferably 1 μm or more and 12 μm or less in diameter. If it is smaller than 1 μm, there is a fear of moving, and if it exceeds 12 μm, the deformation of the raceway is large, which causes torque fluctuation. The preload applying method may be a so-called resonance press-fitting method (resonance management) in which the inner ring 5 is press-fitted while being vibrated and the preload control is performed while measuring the resonance frequency on the outer ring 6 side. Since both the inner and outer rings 5 and 6 are press-fitted and fixed to the shaft member 3 and the housing 4, the problem of outgassing due to the adhesive is eliminated.
[0010]
The axial length a of the fitting portion 4a of the housing 4 that is press-fitted into the outer diameter portion of the outer ring 6 is less than half the width L of the ball bearing 2 on the contact side between the raceway surface of the outer ring 6 and the ball 7. It is a length. Since the outer ring 6 is deformed by the interference force caused by the press-fitting, the groove R is reduced and high rigidity can be achieved.
[0011]
In order to prevent a change in the preload of the ball bearing, it is desirable that the shaft member 3 and the housing 4 have the same thermal expansion coefficient, and austenitic stainless steels, ferritic stainless steels, or austenitic stainless steels. A combination of ferritic stainless steel is preferred. In particular, ferritic stainless steel is suitable for the material of the shaft member 3 and the housing 4 because it has good corrosion resistance and machinability.
[0012]
FIG. 2 is a sectional view showing a second embodiment of the rolling bearing device for swing arm according to the present invention. The difference from the first embodiment is that the axial length of the fitting portion of the inner diameter portion of the inner ring is set to a length less than half the width of the ball bearing on the contact surface between the raceway surface and the ball.
The swing arm rolling bearing device 11 includes a ball bearing 12, a shaft member 13, and a housing 14. The inner ring 15 and the outer ring 16 of the ball bearing 12 are press-fitted and fixed to the shaft member 13 and the housing 14, respectively. Since both the inner and outer rings 15 and 16 are press-fitted and fixed to the shaft member 13 and the housing 14, the problem of outgassing due to the adhesive is eliminated.
Further, the axial length b of the fitting portion 13a of the shaft member 13 press-fitted into the inner diameter portion of the inner ring 15 is less than half the width L of the ball bearing 12 on the contact side between the raceway surface of the inner ring 15 and the ball 17. It is a length. Since the inner ring 15 is deformed by the interference force due to the press-fitting, the groove R becomes small and high rigidity can be achieved.
[0013]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
According to the present invention, the bearing ring of the rolling bearing is press-fitted and fixed to the shaft member and the housing, respectively, and the axial length of at least one fitting portion of the bearing ring of the rolling bearing is determined on the contact side between the raceway surface and the ball, By making the length less than half of the width of the rolling bearing, the rigidity can be increased without changing the internal specifications of the rolling bearing, and the cost can be reduced.
Further, since the race ring is press-fitted and fixed without using an adhesive, there is no outgas due to the adhesive, which is optimal for a rolling bearing for a swing arm of a magnetic disk device.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a first embodiment of a rolling bearing device for a swing arm according to the present invention.
FIG. 2 is a sectional view showing a second embodiment of the rolling arm rolling bearing device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 11 ... Rolling bearing apparatus 2 for swing arms 2, 12 ... Ball bearing 3, 13 ... Shaft member 4, 14 ... Housing 5, 15 ... Inner ring 6, 16 ... Outer ring 7 , 17 ... Ball 4a ··· Fit portion 13a ··· Fit portion L ··· Ball bearing width a, b ··· Axial length of fit portion

Claims (1)

The bearing ring of the rolling bearing is press-fitted and fixed to the shaft member and the other member, respectively, and at least one fitting part of the bearing ring is provided only on the contact side between the raceway surface of the bearing ring and the rolling element, and the fitting part The axial length of the bearing ring is set to be less than half the width of the rolling bearing on the contact side between the raceway surface of the raceway and the rolling element, and the raceway is press-fitted into the shaft member and the other member, respectively. The interference when the diameter is set to 1 μm or more and 12 μm or less to reduce the groove R on the raceway surface on the contact side of the raceway with the rolling element, and without using an adhesive. A rolling bearing device for a swing arm characterized by being press-fitted and fixed.

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