JP2011204317A - Rolling bearing device and pivot device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have sufficient joint strength, to improve productivity, to reduce occurrence of outgassing, and to prevent occurrence of fluctuation of resonance frequency and fluctuation of torque.SOLUTION: A rolling bearing device is equipped with: inner rings 3a, 3b, and an outer ring, coaxially arranged; and a plurality of rolling elements which are arranged keeping interval in the circumferential direction in a circular type space between these inner rings 3a and 3b, the device is also equipped with: a two rolling bearings arranged keeping interval in the axis direction; and a sleeve having a fitting hole fitting shafts 13 fitted to each inner ring 3a, 3b of the two rolling bearings and each outer ring, the sleeve is provided so as to attach a swing arm to the sleeve, a chamfering part in which corner parts are chamfered is provided at the inner periphery edge of the inner rings 3a, 3b, and the rolling bearing is laser-welded with the shaft 13 by a welding range W having diameter dimension being larger than chamfering dimension in the diameter direction of the chamfering part.

Description

  The present invention relates to a rolling bearing device and a pivot device.

  Generally, a rolling bearing device is composed of a rolling bearing having an inner ring and an outer ring arranged coaxially, an inner cylinder fitted to the inner ring of the rolling bearing, and an outer cylinder fitting the outer ring of the rolling bearing. The cylinder and the outer cylinder are supported by a rolling bearing so as to be relatively rotatable (see, for example, Patent Document 1 and Patent Document 2). In the rolling bearing device described in Patent Document 1, a shaft (inner cylinder), an inner ring, a housing (outer cylinder), and an outer ring are joined by an adhesive, respectively. In the rolling bearing device described in Patent Document 2, the shaft and the inner ring are anaerobic. It is joined by a sex adhesive.

Japanese Patent Laid-Open No. 11-182543 JP 2000-346085 A

  However, the anaerobic adhesive has many outgas components and has a disadvantage that the curing time is long and the productivity is low. In addition, when the shaft and the inner ring and the housing and the outer ring are joined together by an adhesive as in the conventional rolling bearing device, the rigidity of the adhesive fluctuates due to a temperature change, and this changes the preload, thereby changing the resonance frequency (resonance) and There is an inconvenience that the torque fluctuates. In addition, even when laser welding is performed, if there is a gap between the workpieces due to chamfering or the like, the welding area becomes large, and the position is displaced due to thermal contraction when the melted portion is cured, resulting in a decrease in torque. There is.

  The present invention has been made in view of the above-described circumstances, and has rolling strength that has sufficient bonding strength, improves productivity, reduces outgassing, and prevents occurrence of resonance frequency fluctuation and torque fluctuation. An object is to provide a bearing device and a pivot device.

In order to achieve the above object, the present invention provides the following means.
The present invention relates to a rolling bearing device for swingably supporting a swing arm of a hard disk, and is arranged in an annular space between an inner ring and an outer ring arranged coaxially and an annular space between the inner ring and the outer ring. A plurality of rolling elements arranged at intervals, and two rolling bearings arranged at intervals in the axial direction, and a first member fitted to each inner ring of the two rolling bearings, or A second member having a fitting hole for fitting each of the outer rings, wherein the outer ring or the inner ring is provided so that the swing arm can be mounted, and at least one of an inner peripheral edge of the inner ring and an outer peripheral edge of the outer ring A chamfered portion is formed by chamfering a corner portion, and at least one of the inner peripheral edge of the inner ring and the outer peripheral edge of the outer ring having the chamfered portion has a diameter dimension larger than a radial chamfer dimension of the chamfered section. Providing a rolling bearing device that is laser welded to the first member or the second member by a contact range.

  According to the present invention, if the swing arm is attached to the inner ring or the outer ring of the two rolling bearings, the swing arm can be swingably supported using the two rolling bearings as fulcrums. In this case, at least one portion of the fitting portion between each inner ring and the first member or the fitting portion between each outer ring and the second member is formed by the chamfered portion with the inner ring and the first member or outer ring and the second member. The members can be fitted together smoothly and without being damaged, and the disturbance of the torque group due to the deterioration of the rotation accuracy can be prevented.

  Moreover, even if there is a gap due to the chamfered portion in the fitting portion by laser welding with a welding range having a larger diameter than the chamfered portion in the radial direction of the chamfered portion, the inner ring and the first member or the outer ring and the second member Can be joined with a sufficient melting amount to ensure the joining strength.

  Further, by joining the fitting portions by laser welding, it is possible to prevent outgassing as in the case of joining using an anaerobic adhesive, and it is possible to shorten the joining time and improve productivity. Further, it is possible to avoid a preload change caused by a change in the rigidity of the adhesive due to a temperature change as in the case where an adhesive is used, and to stabilize the resonance frequency and torque.

  In the said invention, it is good also as the said welding range by the said laser welding having a diameter dimension smaller than 200 micrometers.

  If the amount of material to be welded is too large, thermal shrinkage when the melted portion is cured may increase, and the materials to be welded may be misaligned. By making the diameter dimension (spot diameter) of the welding range by laser welding smaller than 200 μm, it is possible to limit the melting amount and suppress the positional deviation between the inner ring and the first member or the outer ring and the second member. As a result, even when preload is applied to the two rolling bearings, it is possible to prevent the preload from being lost due to the displacement of the fitting portion, and to obtain a desired torque.

  Moreover, in the said invention, it is good also as a diameter dimension of the welding range by the said laser welding being 150-100 micrometers.

  If the spot diameter by laser welding is too small with respect to the chamfer dimension in the radial direction of the chamfered portion, the welded materials cannot be joined with a sufficient amount of melting, and the joining strength may not be ensured. By setting the spot diameter by laser welding to 150 to 100 μm, it is possible to suppress misalignment due to thermal contraction of the melted portion and to secure the bonding strength of the fitting portion.

  In the above invention, a spacer portion sandwiched in the axial direction is provided between one of the outer rings or the inner rings, and the other inner ring or the outer ring is relative to the inner ring or the outer ring adjacent in the axial direction. Alternatively, laser welding may be performed on the first member or the second member in a state where the first member or the second member is pressed in the direction of approaching each other.

  With this configuration, a gap corresponding to the length of the spacer portion is formed between the other inner rings or the outer rings by the spacer portion sandwiched between the outer rings or the inner rings. Alternatively, the state in which the preload is applied to the two rolling bearings can be easily and stably maintained by laser welding with the first member or the second member in a state where the outer rings are relatively close to each other in the axial direction. be able to.

  The present invention comprises a base member, the swing arm, and the rolling bearing device of the present invention, wherein the first member or the second member is fixed to the base member, and the outer ring or the inner ring Provided is a pivot device to which a swing arm is attached.

  According to the present invention, with the two rolling bearings of the rolling bearing device, with respect to the base member fixed to the first member or the second member, the swing arm mounted on the outer ring or the inner ring is stabilized with the resonance frequency. It can be swung with torque.

  The present invention relates to a rolling bearing device for swingably supporting a swing arm of a hard disk, and is arranged in an annular space between an inner ring and an outer ring arranged coaxially and an annular space between the inner ring and the outer ring. A plurality of rolling elements arranged at intervals, two rolling bearings arranged at intervals in the axial direction, a first member fitted to each inner ring of the two rolling bearings, A second member having a fitting hole for fitting each outer ring of two rolling bearings, wherein the first member or the second member is provided so that the swing arm can be mounted, At least one of the inner peripheral edge and the outer peripheral edge of the outer ring is provided with a chamfered portion, and at least one of the inner peripheral edge of the inner ring and the outer peripheral edge of the outer ring having the chamfered portion is the chamfered portion. Radial chamfer Providing a rolling bearing device that is laser welded to the first member or the second member by welding range with diameter larger than the dimension.

  According to the present invention, a plurality of rolling elements roll in an annular space between each inner ring and each outer ring of the two rolling bearings, so that the first member and each outer ring fitted to each inner ring are The fitted second member is relatively rotated about the axis of the two rolling bearings. Therefore, if the swing arm is attached to the first member or the second member, the swing arm can be swingably supported using the two rolling bearings as fulcrums.

  In this case, at least one portion of the fitting portion between each inner ring and the first member and the fitting portion between each outer ring and the second member is formed by the chamfered portion with the inner ring and the first member or the outer ring and the second member. The members can be fitted together smoothly and without being damaged, and the disturbance of the torque group due to the deterioration of the rotation accuracy can be prevented. Also, laser welding is performed in a welding range in which the diameter dimension is larger than the chamfer dimension in the radial direction of the chamfered portion, thereby joining the inner ring and the first member or the outer ring and the second member with a sufficient amount of melting to ensure the bonding strength. be able to.

  Further, by joining the fitting portions by laser welding, generation of outgas can be prevented and the joining time can be shortened and the productivity can be improved. Further, it is possible to avoid a change in preload due to a change in the rigidity of the adhesive due to a temperature change, and to stabilize the resonance frequency and torque.

In the said invention, it is good also as the said welding range by the said laser welding having a diameter dimension smaller than 200 micrometers.
By comprising in this way, the amount of fusion | melting can be restrict | limited and the position shift of an inner ring | wheel and a 1st member or an outer ring | wheel and a 2nd member can be suppressed. Accordingly, when preload is applied to the two rolling bearings, it is possible to prevent the preload from being lost due to the displacement of the fitting portion and obtain a desired torque.

Moreover, in the said invention, it is good also as a diameter dimension of the welding range by the said laser welding being 150-100 micrometers.
By comprising in this way, the position shift by the thermal contraction of a fusion | melting part can be suppressed, and the joining strength of a fitting part can be ensured.

In the above invention, a spacer portion sandwiched in the axial direction is provided between one of the outer rings or the inner rings, and the other inner ring or the outer ring is relative to the inner ring or the outer ring adjacent in the axial direction. Alternatively, laser welding may be performed on the first member or the second member in a state where the first member or the second member is pressed in the direction of approaching each other.
By comprising in this way, the state which applied the pre-load to two rolling bearings can be maintained easily and stably.

  The present invention includes a base member, the swing arm, and the rolling bearing device of the present invention, wherein one of the first member and the second member is fixed to the base member, A pivot device in which the swing arm is mounted on a second member or the first member is provided.

  According to the present invention, the first member and the second member are relatively rotated by the two rolling bearings of the rolling bearing device, so that the base member is fixed to the first member or the second member. On the other hand, the swing arm mounted on the other side can be swung with a stable resonance frequency and torque.

  According to the present invention, there is an effect that it has sufficient joint strength, improves productivity and reduces outgas generation, and can prevent occurrence of resonance frequency fluctuation and torque fluctuation.

It is a longitudinal cross-sectional view of the pivot apparatus which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view of the rolling bearing apparatus of FIG. It is a longitudinal cross-sectional view of the fitting part of the inner ring | wheel and the shaft before the laser welding of FIG. It is a longitudinal cross-sectional view of the state which laser-welded the fitting part of FIG. It is a top view which shows the welding range of FIG. It is a figure which shows the relationship between the chamfering dimension of a chamfering part, and the deviation | shift amount of a fitting part. It is a figure which shows the relationship between the chamfering dimension of a chamfering part, and the spot diameter of a welding range.

Hereinafter, a rolling bearing device and a pivot device according to an embodiment of the present invention will be described with reference to the drawings.
The pivot device 50 according to the present embodiment is used in a hard disk drive device, for example, as shown in FIG. The pivot device 50 includes a base housing (base member) 51, a swing arm 53, and a rolling bearing device 10 that supports the swing arm 53 in a swingable manner with respect to the base housing 51.

A recess 52 for attaching the rolling bearing device 10 is formed on the lower end surface of the base housing 51.
The swing arm 53 has a cylindrical main body 55 having a bearing fitting hole 54 into which the rolling bearing device 10 is fitted, and a plurality of (here, five) arranged in multiple stages along the axial direction of the cylindrical main body 55. Arm portions 57 and a magnetic head (not shown) provided at the tip of each arm portion 57 for writing magnetic information on a hard disk (not shown) and reading recorded magnetic information.

  As shown in FIG. 2, the rolling bearing device 10 is fitted to the first rolling bearing 1 </ b> A and the second rolling bearing 1 </ b> B arranged coaxially with an interval in the axial direction, and the rolling bearings 1 </ b> A and 1 </ b> B. A shaft (first member) 13 and a sleeve (second member) 23 having a fitting hole 25 into which the rolling bearings 1A and 1B are fitted.

  The first rolling bearing 1A includes an inner ring 3a and an outer ring 5a that are arranged coaxially, and a plurality of rolling elements 7 that are built in an annular space between the inner ring 3a and the outer ring 5a with a circumferential interval therebetween. And. The second rolling bearing 1B has the same configuration as that of the first rolling bearing 1A, and includes an inner ring 3b and an outer ring 5b, and a plurality of rolling elements 7. Each rolling element 7 is held so as to be able to roll in a state of being arranged at equal intervals by a retainer (not shown).

  These rolling bearings 1A and 1B have, for example, an outer dimension of about 9.525 mm and an inner diameter of about 6.35 mm. Deep groove or angular inner ring raceways are provided on the outer peripheral surfaces of the inner rings 3a and 3b of the rolling bearings 1A and 1B, respectively, and deep groove or angular outer ring raceways are provided on the inner peripheral surfaces of the outer rings 5a and 5b, respectively. Is provided.

  Further, as shown in FIG. 3, chamfered portions 4a and 4b formed by chamfering corner portions in the circumferential direction are formed on the inner peripheral edges of the inner rings 3a and 3b, respectively. The chamfered portions 4a and 4b preferably have, for example, a radial chamfer dimension of about 10 to 100 μm. By doing in this way, it is possible to fit the inner rings 3a, 3b and the shaft 13 smoothly and without damage by the chamfered portions 4a, 4b.

  For example, if the chamfered dimensions of the chamfered portions 4a and 4b are 5 μm or less, burrs from cutting remain on the inner peripheral edges of the inner rings 3a and 3b, and the inner rings 3a and 3b and the shaft 13 cannot be smoothly fitted to each other and are damaged. May end up. Note that the chamfered dimensions of the chamfered portions 4a and 4b may be smaller than 10 μm as long as the inner rings 3a and 3b and the shaft 13 can be smoothly and accurately fitted without being damaged.

  A shaft 13 is fitted to these inner rings 3a and 3b. As shown in FIGS. 4 and 5, the fitting portion between the inner rings 3a and 3b and the shaft 13 is formed by laser welding around the portion where the chamfered portions 4a and 4b of the inner rings 3a and 3b and the outer peripheral surface of the shaft 13 intersect. It is joined. A symbol W indicates a welding range by laser welding.

  The welding range W has a substantially circular shape centered around the boundary between the chamfered portions 4 a and 4 b of the inner rings 3 a and 3 b and the outer peripheral surface of the shaft 13. Further, the welding range W has a diameter dimension larger than the chamfer dimension in the radial direction of the chamfered portions 4a and 4b of the inner rings 3a and 3b. Hereinafter, the diameter of the welding range W is referred to as a spot diameter.

  The spot diameter of the welding range W is set according to the chamfered dimensions of the chamfered portions 4a and 4b described above, and is preferably smaller than 200 μm, for example, about 100 to 150 μm. The fitting portions between the inner rings 3a and 3b and the shaft 13 are laser-welded at a plurality of locations (for example, three locations) with a welding range W at intervals in the circumferential direction.

  The outer rings 5a and 5b are fitted in the fitting holes 25 of the sleeve 23, respectively. In these fitting portions, for example, the inner peripheral surface of the fitting hole 25 and the outer peripheral surfaces of the outer rings 5a and 5b are joined by an adhesive. Examples of the adhesive include an anaerobic adhesive and a thermosetting adhesive.

  The shaft 13 is a substantially cylindrical member. For example, a shaft having a diameter of about 6.3 mm or less is used. One end of the shaft 13 in the axial direction is provided with a flange-like flange portion 15 projecting radially outward over the entire circumference and a male thread forming projection 17 projecting in the axial direction. A screw hole 19 extending in the axial direction is formed at the other end of the shaft 13 in the axial direction.

  In the shaft 13, the protrusion 17 is fitted in the recess 52 on the lower end surface of the base housing 51, and a screw (not shown) is inserted into the screw hole 19 from the outside of the base housing 51, whereby the base housing 51 is rotated on the rotation axis C. The upper end surface of 51 is fixed with screws.

  Further, the shaft 13 is fitted with the first rolling bearing 1A and the second rolling bearing 1B in order from the flange portion 15 side, and the end surface of the inner ring 3a of the first rolling bearing 1A abuts against the flange portion 15. It has been. Hereinafter, a fitting portion between the shaft 13 and the inner ring 3a of the first rolling bearing 1A is referred to as a “first fitting portion 29A”, and a fitting portion between the shaft 13 and the inner ring 3b of the second rolling bearing 1B is referred to. This is referred to as “second fitting portion 29B”.

  Further, the inner rings 3a and 3b of the rolling bearings 1A and 1B are joined to the shaft 13 in a state where they are pressed in directions approaching each other. As a result, a preload is applied to the rolling bearings 1A and 1B, and the inner rings 3a and 3b and the outer rings 5a and 5b and the rolling elements 7 are brought into contact with no gap.

  The sleeve 23 is a substantially cylindrical member, and its outer peripheral surface is fitted in the bearing fitting hole 54 of the swing arm 53. The fitting hole 25 of the sleeve 23 is provided with a convex portion (hereinafter referred to as a “spacer portion”) 27 that protrudes inward in the radial direction at substantially the center in the axial direction.

  The fitting hole 25 is fitted with the first rolling bearing 1A on one side in the axial direction and the second rolling bearing 1B on the other side across the spacer portion 27, and the end faces of the outer rings 5a and 5b facing each other. Are abutted against the spacer portion 27. Hereinafter, a fitting portion between the fitting hole 25 and the outer ring 5a of the first rolling bearing 1A is referred to as a “third fitting portion 29C”, and the fitting hole 25 and the outer ring 5b of the second rolling bearing are fitted. The joint portion is referred to as “second fitting portion 29D”.

Hereinafter, a method for manufacturing the rolling bearing device 10 and the pivot device 50 configured as described above will be described.
First, the shaft 13 is fitted to the inner ring 3 a of the first rolling bearing 1 </ b> A, and the end surface of the inner ring 3 a is abutted against the flange portion 15 of the shaft 13. Then, laser welding is performed around the portion where the chamfered portion 4a of the end surface opposite to the end surface abutted against the flange portion 15 of the inner ring 3a intersects with the outer peripheral surface of the shaft 13, and the first fitting portion 29A is joined. To do.

  Here, for example, if the spot diameter of the welding range W is made smaller than the chamfer dimension of the chamfered portion 4a, a sufficient amount of melting of the inner ring 3a and the shaft 13 cannot be obtained, and the fitting portion cannot be joined. In the rolling bearing device 10 according to the present embodiment, by making the chamfer dimension of the chamfered portion 4a of the inner ring 3a about 10 to 100 μm, the assemblability is good and the disturbance of the torque group due to the deterioration of the rotation accuracy is prevented. Can do. Further, by setting the spot diameter of the welding range W to about 100 to 150 μm, which is larger than the chamfer dimension of the chamfered portion 4a, regardless of the gap by the chamfered portion 4a between the outer peripheral surface of the shaft 13 and the inner peripheral edge of the inner ring 3a, The inner ring 3a and the shaft 13 can be joined with a sufficient amount of melting to ensure the joining strength.

  Next, an adhesive is applied to the fitting hole 25 of the sleeve 23 or the outer peripheral surface of the outer ring 5b of the second rolling bearing 1B. Then, the outer ring 5 b is fitted into the fitting hole 25, and the end surface of the outer ring 5 b is abutted against the spacer portion 27 of the fitting hole 25.

  Subsequently, an adhesive is applied to the outer peripheral surface of the outer ring 5 a of the first rolling bearing or the fitting hole 25 of the sleeve 23. Then, in a state where the shaft 13 fitted to the first rolling bearing 1A is fixed so that the flange portion 15 faces vertically downward, the sleeve 23 fitted with the second rolling bearing 1B is fitted.

  Specifically, the shaft 13 is fitted to the inner ring 3b of the second rolling bearing 1B fitted into the sleeve 23, and the outer ring 5a of the first rolling bearing 1A fitted with the shaft 13 is fitted to the first rolling bearing 1B. The end portion of the outer ring 5 a is abutted against the spacer portion 27 by being fitted to the fitting portion 29 </ b> A.

In this state, the second fitting portion 29B is joined by laser welding.
Here, a gap corresponding to the length of the spacer portion 27 is formed between the inner rings 3a and 3b by the spacer portion 27 sandwiched between the outer rings 5a and 5b of the rolling bearings 1A and 1B. A preload is applied to the rolling bearings 1A and 1B by pressing the inner ring 3b toward each other.

  In this case, since the inner ring 3a of the first rolling bearing 1A is abutted against the flange portion 15 of the shaft 13, the inner ring 3b of the second rolling bearing 1B is pressed in the axial direction against the inner ring 3a. It is possible to apply a preload to both the rolling bearings 1A and 1B simply by making them.

  Thus, laser welding is performed around a portion where the chamfered portion 4b of the inner ring 3b intersects with the outer peripheral surface of the shaft 13 while the inner ring 3b is pressed in the axial direction. Thereby, the 2nd fitting part 29B is joined and the state by which the preload was applied to rolling bearing 1A, 1B is maintained.

  In this case, for example, if the spot diameter of the welding range W is made too large with respect to the chamfer dimension of the chamfered portion 4b (for example, if the spot diameter is 200 μm or more), the melting amount of the inner ring 3b and the shaft 13 is necessary for joining. As shown in FIG. 6, the heat shrinkage when the melted molten portion is cured increases, and the positional deviation between the inner ring 3 b and the shaft 13 increases.

  In the rolling bearing device 10 according to the present embodiment, the chamfer dimension of the chamfered portion 4b of the inner ring 3b is set to about 10 to 100 μm, and the spot diameter of the welding range W is set to about 100 to 150 μm. First, the inner ring 3b and the shaft 13 are joined with a sufficient melting amount to ensure the joining strength, and the thermal contraction when the melted molten part is cured is reduced, thereby suppressing the positional deviation between the inner ring 3b and the shaft 13. Can do. Accordingly, it is possible to prevent the preload from being lost and to apply a stable preload. Further, as shown in FIG. 7, the assemblability is good, the disturbance of the torque group due to the deterioration of the rotation accuracy is prevented, and a stable torque and resonance can be obtained.

  Subsequently, when the other third fitting portion 29C and the fourth fitting portion 29D are joined with an adhesive, the rolling bearing device 10 is completed. For example, when an anaerobic adhesive is used as the adhesive, the adhesive is cured by being left for a predetermined time, and the fitting portions 29C and 29D are joined. When a thermosetting adhesive is used as the adhesive, the adhesive is cured by applying predetermined heat, and the fitting portions 29C and 29D are joined.

  In the rolling bearing device 10 manufactured as described above, a plurality of rolling elements 7 roll in an annular space between the inner rings 3a and 3b and the outer rings 5a and 5b of the two rolling bearings 1A and 1B. Thus, the shaft 13 fitted to each inner ring 3a, 3b and the sleeve 23 fitted to each outer ring 5a, 5b are relatively rotated around the axis of the rolling bearing 1A, 1B.

  Then, the swing arm 53 is attached to the sleeve 23, the projection 17 of the shaft 13 is fitted into the recess 52 on the lower end surface of the base housing 51, and the rolling bearing device 10 is fixed. Hereinafter, the operation of the pivot device 50 will be described.

  When a driving unit (not shown) such as a voice coil motor is operated, a swing arm 53 that fits the sleeve 23 against the base housing 51 to which the shaft 13 of the rolling bearing device 10 is fitted causes the rolling bearing device 10 to move. It is swung around the rotation axis C as a fulcrum. Thereby, each magnetic head is reciprocated on each hard disk.

  For example, by operating the swing arm 53 at a high speed, each magnetic head is instantaneously moved to data recorded at a predetermined position on each hard disk, and reading of magnetic information recorded on the hard disk and writing of magnetic information are performed. It can be performed.

  As described above, according to the rolling bearing device 10 and the pivot device 50 according to the present embodiment, the fitting portions 29A and 29B are laser-welded by the welding range W in which the spot diameter is larger than the chamfer dimension of the chamfered portions 4a and 4b. Thus, the inner rings 3a, 3b and the shaft 13 can be joined with a sufficient amount of melting regardless of the gaps between the chamfered portions 4a, 4b, and the joining strength can be ensured.

  Further, compared to the case where all the fitting portions 29A, 29B, 29C, and 29D are joined with an adhesive, the outgas generation is reduced, and the joining time is shortened and the productivity can be improved. In addition, according to laser welding, it is possible to avoid a change in preload due to a change in the rigidity of the adhesive due to a change in temperature as in the case of joining with an adhesive, and to stabilize resonance and torque. Therefore, the swing arm 53 can be swung with stable resonance and torque with respect to the base housing 51.

  In the present embodiment, the chamfered portions 4a and 4b are formed only on the inner peripheral edges of the inner rings 3a and 3b, but at least one of the inner peripheral edges of the inner rings 3a and 3b and the outer peripheral edges of the outer rings 5a and 5b. One has a chamfered portion, and at least one of the inner peripheral edge of the inner rings 3a and 3b and the outer peripheral edge of the outer rings 5a and 5b having the chamfered part may be laser-welded to the shaft 13 or the sleeve 23.

  For example, chamfered portions are formed on the outer peripheral edges of the outer rings 5a and 5b, the outer rings 5a and 5b and the fitting hole 25 of the sleeve 23 are joined by laser welding, and the inner rings 3a and 3b and the shaft 13 are joined by an adhesive. It is good. Further, chamfered portions are formed on all of the inner peripheral edges of the inner rings 3a and 3b and the outer peripheral edges of the outer rings 5a and 5b, and all the fitting portions 29A, 29B, 29C, and 29D are joined by laser welding, or laser welding is performed. It is good also as joining together using an adhesive.

Moreover, in this embodiment, although three places were laser-welded in the circumferential direction of fitting part 29A, 29B, for example, two or less places of the circumferential direction or four or more places of the circumferential direction are laser-welded. It is good as well.
In this embodiment, the swing arm 53 is attached to the sleeve 23 and the shaft 13 is fixed to the base housing 51. For example, the swing arm is attached to the shaft 13 and the sleeve 23 is fixed to the base member. It is good to do. Further, for example, the outer rings 5a and 5b may be directly fitted into the bearing fitting holes of the swing arm without using the sleeve 23. Further, for example, when the sleeve 23 is fixed to the base member, the swing arm may be directly fitted to the inner rings 3 a and 3 b without using the shaft 13.

  In the present embodiment, the rolling bearings 1A and 1B having an outer dimension of about 9.525 mm and an inner diameter of about 6.35 mm have been described as examples. However, as the rolling bearing, for example, the outer dimension is about 8 mm. Examples include those having an inner diameter of about 5 mm, those having an outer dimension of about 7 mm and an inner diameter of about 4 mm, and those having an outer dimension of about 5 mm and an inner diameter of about 2.5 mm.

Further, the present embodiment may be modified as follows.
For example, in the same fitting portions 29A, 29B, 29C, and 29D, laser welding may be further performed in a welding range having a spot diameter different from that of the first laser welding. For example, first, the inner rings 3a and 3b or the outer rings 5a and 5b are laser-welded with a spot diameter of laser light that does not cause a position shift due to thermal contraction, and then the same position as the first welding position, May be laser-welded at a position shifted in the circumferential direction with a spot diameter (laser power higher than the initial laser power) larger than the spot diameter by the initial laser welding.

  By doing in this way, it can fix with high precision, maintaining the shape of inner ring 3a, 3b or outer ring 5a, 5b substantially by the first laser welding. Next, when laser welding is performed with high laser power, even when a force that relatively changes the inner rings 3a and 3b and the shaft 13 or the outer rings 5a and 5b and the sleeve 23 acts due to thermal contraction of the welded portion. Further, it is possible to join with high joining strength while suppressing the displacement of the fitting portion by the fixing force of the welded part by the first laser welding.

DESCRIPTION OF SYMBOLS 1A 1st rolling bearing 1B 2nd rolling bearing 3a, 3b Inner ring 4a, 4b Chamfer part 5a, 5b Outer ring 7 Rolling body 10 Rolling bearing apparatus 13 Shaft (1st member)
23 Sleeve (second member)
25 Fitting hole 50 Pivot device 51 Base housing (base member)
53 Swing arm

Claims (10)

A rolling bearing device for swingably supporting a swing arm of a hard disk,
The inner ring and the outer ring arranged coaxially, and a plurality of rolling elements arranged in the annular space between the inner ring and the outer ring at intervals in the circumferential direction, are arranged with an interval in the axial direction 2 With two rolling bearings,
A first member fitted to each inner ring of the two rolling bearings, or a second member having a fitting hole for fitting each outer ring;
The outer ring or the inner ring is provided so that the swing arm can be mounted,
At least one of the inner peripheral edge of the inner ring and the outer peripheral edge of the outer ring is provided with a chamfered portion, and at least one of the inner peripheral edge of the inner ring and the outer peripheral edge of the outer ring having the chamfered portion is the A rolling bearing device that is laser-welded to the first member or the second member by a welding range having a diameter dimension larger than a chamfer dimension in a radial direction of a chamfered portion.   The rolling bearing device according to claim 1, wherein the welding range by the laser welding has a diameter smaller than 200 μm.   The rolling bearing device according to claim 1, wherein a diameter dimension of a welding range by the laser welding is 150 to 100 μm. A spacer portion sandwiched in the axial direction between one of the outer rings or the inner rings,
The other inner ring or the outer ring is laser welded to the first member or the second member in a state of being pressed in a direction relatively close to the inner ring or the outer ring adjacent in the axial direction. The rolling bearing device according to any one of claims 1 to 3.   A base member, the swing arm, and the rolling bearing device according to any one of claims 1 to 4, wherein the first member or the second member is fixed to the base member, and the outer ring Alternatively, a pivot device in which the swing arm is attached to the inner ring. A rolling bearing device for swingably supporting a swing arm of a hard disk,
The inner ring and the outer ring arranged coaxially, and a plurality of rolling elements arranged in the annular space between the inner ring and the outer ring at intervals in the circumferential direction, are arranged with an interval in the axial direction 2 With two rolling bearings,
A first member fitted to each of the inner rings of the two rolling bearings;
A second member having a fitting hole for fitting the outer rings of the two rolling bearings;
The first member or the second member is provided so that the swing arm can be mounted,
At least one of the inner peripheral edge of the inner ring and the outer peripheral edge of the outer ring is provided with a chamfered portion, and at least one of the inner peripheral edge of the inner ring and the outer peripheral edge of the outer ring having the chamfered portion is the A rolling bearing device that is laser-welded to the first member or the second member by a welding range having a diameter dimension larger than a chamfer dimension in a radial direction of a chamfered portion.   The rolling bearing device according to claim 6, wherein the welding range by the laser welding has a diameter smaller than 200 μm.   The rolling bearing device according to claim 6 or 7, wherein a diameter of a welding range by the laser welding is 150 to 100 µm. A spacer portion sandwiched in the axial direction between one of the outer rings or the inner rings,
The other inner ring or the outer ring is laser welded to the first member or the second member in a state of being pressed in a direction relatively close to the inner ring or the outer ring adjacent in the axial direction. The rolling bearing device according to any one of claims 6 to 8.   A base member, the swing arm, and the rolling bearing device according to claim 6, wherein one of the first member and the second member is fixed to the base member. A pivot device in which the swing arm is attached to the other second member or the first member.

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