JP2014160521A - Swing arm, information recording and reproduction system, and assembly method for swing arm - Google Patents

Abstract

A swing arm, an information recording / reproducing apparatus, and a swing arm assembling method capable of improving quality are provided.
A swing arm 8A includes a rotating member 11 having a base portion 11a in which a through hole 12 is formed, and an arm portion 11b protruding from the base portion 11a, and the through hole 12 formed in the base portion 11a. And a bearing device 10 that supports the rotating member 11 so as to be rotatable about the axis of the through hole 12, and the shaft of the through hole 12 is formed on the inner peripheral surface 12 a of the through hole 12. A step portion 15 is provided at a central portion in the direction so as to protrude inward in the radial direction of the through hole 12. The bearing device 10 includes a shaft 20 inserted into the through hole 12, and the through hole. A pair of rolling bearings 31, 32 press-fitted between the inner peripheral surface of the shaft 12 and the outer peripheral surface of the shaft 20, and the pair of rolling bearings 31, 32 are axially arranged with respect to the stepped portion 15. Placed on both sides That.
[Selection] Figure 2

Description

  The present invention relates to a swing arm, an information recording / reproducing apparatus, and a method for assembling a swing arm.

2. Description of the Related Art Conventionally, information recording / reproducing apparatuses such as hard disk drives for storing and reproducing various types of information on a disk (magnetic recording medium) are known. In general, an information recording / reproducing apparatus includes a head gimbal assembly having a slider for recording / reproducing a signal on a disk, and a swing arm having the head gimbal assembly mounted on the tip side.
The swing arm includes a base having a through hole formed therein, a rotating member having a plurality of arm portions protruding from the base and spaced apart in the axial direction of the through hole, and a through hole formed in the base. And a bearing device that supports the rotating member so as to be rotatable about the axis of the through hole. The bearing device includes a shaft inserted into the through hole, and a pair of rolling bearings provided between the inner peripheral surface of the through hole and the outer peripheral surface of the shaft. By rotating the swing arm, the slider can be moved to a predetermined position on the disk, and signals can be recorded and reproduced.

By the way, in this swing arm, a pre-assembled bearing device is inserted into the through hole and fixed to the through hole.
Patent Document 1 discloses a configuration in which a bearing device is fixed to a through hole with an adhesive.
Patent Document 2 discloses a configuration in which an outer peripheral portion of a bearing device and a tolerance ring are provided, and the bearing device is fixed to the through hole by a tension generated in the tolerance ring by being inserted into the through hole.

JP 2003-269448 A JP 2001-208082 A

However, the conventional swing arm has the following problems.
In the configuration described in Patent Document 1, the thickness of the adhesive applied between the outer peripheral portion of the bearing device and the inner peripheral surface of the through hole and the degree of curing may differ in the circumferential direction. In the configuration described in Patent Document 2, the tension of the tolerance ring may vary in the circumferential direction due to manufacturing errors, residual stresses during manufacturing, and the like. For these reasons, the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing tends to vary from position to position along the circumferential direction of the through hole.
In addition, in both of these configurations, the bearing device may tilt because the insertion stroke for inserting the bearing device into the through hole is long. In this case as well, the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing tends to vary from position to position along the circumferential direction of the through hole.
As described above, if the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing varies from position to position along the circumferential direction of the through hole, there is a problem that torque waves are likely to occur. .

  In the conventional swing arm, when the bearing device is inserted into the through hole, the insertion stroke to the through hole is different between one rolling bearing and the other rolling bearing. The larger the insertion stroke, the more likely the rolling bearing is inclined with respect to the through hole, or the burr generated by the rolling bearing rubbing strongly with the inner peripheral surface of the through hole causes the inner surface of the through hole and the rolling bearing to The possibility of biting in between increases. As a result, the torque may be different between one rolling bearing and the other rolling bearing. Furthermore, there is a possibility that one rolling bearing and the other rolling bearing are misaligned and adversely affect the rolling characteristics of the swing arm.

In addition, when applying a preload to the rolling bearing in the conventional swing arm, the bearing device is inserted into the through hole after applying the preload to the rolling bearing. However, when the bearing device is inserted into the through hole, a compression force is applied to the rolling bearing in the axial direction, which may cause an unexpected torque increase. In addition, after the bearing device is inserted into the through-hole, the compression force is applied to the rolling bearing from the outer peripheral side to the radial inner side due to the hardening of the adhesive and the tension of the tolerance ring, which also increases the torque. There is a fear.
As described above, the conventional swing arm has room for improvement in terms of improving the quality.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a swing arm, an information recording / reproducing apparatus, and a method for assembling a swing arm that can improve quality.

In order to solve the above problems, the present invention proposes the following means.
The swing arm according to the present invention is disposed in a through-hole formed in the base, and a rotating member having a base portion in which a through-hole is formed, an arm portion protruding from the base portion, and the rotating member Is a swing arm for an information recording / reproducing device comprising a bearing device rotatably supported about the axis of the through-hole, and an axially central portion of the through-hole on the inner peripheral surface of the through-hole Is provided with a stepped portion projecting inward in the radial direction of the through hole, and the bearing device includes a shaft inserted into the through hole, an inner peripheral surface of the through hole, and an outer periphery of the shaft. And a pair of rolling bearings press-fitted between the surfaces, and the pair of rolling bearings are disposed on both sides in the axial direction with respect to the stepped portion.

According to this invention, since the pair of rolling bearings are arranged on both sides in the axial direction with respect to the stepped portion, the pair of rolling bearings can be inserted into the stepped portion from both sides in the axial direction. it can. Thereby, the distance by which a rolling bearing is press-fitted can be shortened, and a rolling bearing can be made hard to incline. Further, the shorter the press-fitting distance, the lower the possibility that the burr will bite. Therefore, the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing can be prevented from varying for each position along the circumferential direction of the through hole, and the axis of the pair of rolling bearings It becomes possible to suppress displacement, and generation of torque waves can be suppressed.
In addition, by inserting a pair of rolling bearings from both sides in the axial direction with respect to the stepped portion, it is possible to avoid an increase in the insertion stroke of one of the rolling bearings, and one rolling bearing and the other rolling bearing. Therefore, the insertion stroke into the through hole can be made the same. Thereby, it becomes possible to suppress that a torque differs by one rolling bearing and the other rolling bearing, and generation | occurrence | production of a torque wave can be suppressed reliably.
In addition, there is no need to fix the rolling bearing with an adhesive or a tolerance ring. In this respect as well, the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing is It is possible to suppress variation at each position along the direction. Thereby, generation | occurrence | production of a torque wave can be suppressed more reliably.
In addition, when preload is applied to the rolling bearing, it is possible to apply preload to the rolling bearing after the rolling bearing is press-fitted between the inner peripheral surface of the through hole and the outer peripheral surface of the shaft. Thereby, an unexpected torque increase can be suppressed after the preload is applied.

  Further, at least one of the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing is provided with a burr escape recess into which a burr formed by press-fitting the rolling bearing into the through hole enters. Also good.

  In this case, even if a burr is formed when the rolling bearing is press-fitted into the through hole, this burr is inserted into the burr escape recess to prevent the burr from being caught between the rolling bearing and the through hole. Can do. This also prevents the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing from varying at each position along the circumferential direction of the through hole, thereby suppressing the generation of torque waves. it can.

  Further, the burr escape recess may be formed such that, of the inner peripheral surface of the through hole, a connection portion with the stepped portion is recessed outward in the radial direction.

  In this case, the burr escape recess can be easily formed when the through hole is formed.

  In addition, a plurality of the arm portions are disposed in the base portion at intervals in the axial direction, and at least some of the stepped portions are located inside the axial direction of the plurality of arm portions, A slit portion that opens between the arm portions adjacent to each other in the axial direction may be formed in the base portion, and an end portion on the radially inner side of the slit portion may be located in the stepped portion.

  In this case, the magnetic recording medium can be inserted up to the slit portion by forming the slit portion at the base of the swing arm. As a result, the swing arm can be downsized, and the information recording / reproducing apparatus including the swing arm can be downsized.

  The bearing device may be provided with a hub cap that covers the rolling bearing from the side opposite the stepped portion along the axial direction, and the hub cap may apply a preload to the rolling bearing.

  In this case, since the hub cap applies preload to the rolling bearing, it is possible to apply preload to the rolling bearing by joining the hub cap to the shaft, and there is no need for additional work to apply preload. It can be. Thereby, simplification of manufacture of this swing arm can be achieved.

  Further, the shaft is formed with a recess opening in the axial end surface of the shaft, and the hub cap is joined to the shaft via an insertion portion provided in the hub cap and inserted into the recess. You may be allowed to.

  In this case, since the hub cap is joined to the shaft via the insertion portion, the recess of the shaft and the insertion portion of the hub cap are each formed long in the axial direction while maintaining the size of the shaft in the axial direction. can do. Accordingly, it is possible to ensure a long stroke in the axial direction when inserting the insertion portion into the recess, and to increase the insertion allowance for the recess of the insertion portion. As a result, the hub cap can be assembled to the shaft with high accuracy and firmly bonded while suppressing an increase in size of the bearing device.

  An information recording / reproducing apparatus of the present invention includes the swing arm as described above, a housing connected to the shaft, and a slider that is attached to the rotating member and records and reproduces information on a magnetic recording medium. It is characterized by that.

  According to this invention, since the swing arm is provided, the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing varies from position to position along the circumferential direction of the through hole. It is possible to suppress the displacement of the axial line of the two rolling bearings in the radial direction, and to suppress the generation of torque waves.

  The swing arm assembly method of the present invention includes a base having a through-hole formed therein, a rotating member having an arm projecting from the base, and a through-hole formed in the base. A bearing device that supports the moving member so as to be rotatable about the axis of the through hole. The bearing device includes a shaft that is inserted into the through hole, an inner peripheral surface of the through hole, and the shaft. A swing arm assembly method for forming a swing arm for an information recording / reproducing apparatus comprising a pair of rolling bearings press-fitted between the outer peripheral surfaces of the pair of rolling bearings, and each of the pair of rolling bearings in the through-holes And a press-fitting step of press-fitting from both sides of the through hole in the axial direction.

According to this invention, when the rolling bearing is press-fitted into the through hole from both sides in the axial direction, the force acting between the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing is reduced in the circumferential direction of the through hole. It is possible to suppress variations in positions along the axis, and to prevent the axial line of both rolling bearings from being displaced in the radial direction, thereby suppressing the generation of torque waves.
Further, according to this method, it is not necessary to fix the rolling bearing using an adhesive or a tolerance ring, and it is possible to reduce costs and reduce assembly man-hours by reducing the number of parts.

  Moreover, it is good also as what has a preload process which provides a preload to the said rolling bearing press-fit in the said through-hole.

In this case, after press-fitting the rolling bearing into the through hole, the preload can be adjusted with high accuracy by applying a preload to the rolling bearing.
In addition, since a preload can be applied to the rolling bearing press-fitted between the inner peripheral surface of the through hole and the outer peripheral surface of the shaft, an unexpected increase in torque can be suppressed after the preload is applied.

  In the press-fitting step, the shaft in which the first rolling bearing that is one of the pair of rolling bearings is incorporated is inserted into the through-hole from one side in the axial direction with respect to the through-hole, and the first A step of press-fitting a rolling bearing into the through hole; and a step of press-fitting a second rolling bearing, which is the other of the pair of rolling bearings, into the through hole from the other side in the axial direction with respect to the through hole. You may do it.

  In this case, since the shaft incorporating the first rolling bearing is inserted into the through hole, the first rolling bearing can be smoothly press-fitted into the through hole, and the swing arm can be easily assembled.

  According to the assembly method of the swing arm, the information recording / reproducing apparatus, and the swing arm according to the present invention, the quality can be improved.

It is a perspective view of an information recording / reproducing apparatus. It is side surface sectional drawing in the AA of FIG. It is an expanded sectional view of the important section of the swing arm concerning the modification of a 1st embodiment. It is an expanded sectional view of the important section of the swing arm concerning other modifications of a 1st embodiment. It is side surface sectional drawing of the swing arm which concerns on 2nd Embodiment. It is an expanded sectional view of the important section of the swing arm concerning a 3rd embodiment. It is an expanded sectional view of the important section of the swing arm concerning a 4th embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
(Information recording / reproducing device)
1 is a perspective view of the information recording / reproducing apparatus, and FIG. 2 is a side sectional view taken along line AA of FIG. As shown in FIG. 1, the information recording / reproducing apparatus 1 is an apparatus that performs writing and reading on a disk (magnetic recording medium) D having a recording layer. The information recording / reproducing apparatus 1 scans and moves the swing arm 8A, the head gimbal assembly 4 supported on the front end side of the swing arm 8A, the slider 2 mounted on the front end of the head gimbal assembly 4, and the head gimbal assembly 4. An actuator (VCM: voice coil motor) 6, a spindle motor 7 that rotates the disk D, a control unit 5 that supplies a current modulated according to information to the slider 2, and a housing 9 that accommodates these components inside. And.

  The housing 9 is made of a metal material such as aluminum and has a box-like shape having an opening at the top, and has a rectangular bottom 9a in plan view and a peripheral wall that stands vertically from the peripheral edge of the bottom 9a ( (Not shown). On the inner side of the housing 9 surrounded by the peripheral wall, a recess for accommodating the above-described components is formed. The spindle motor 7 is attached to substantially the center of the bottom portion 9a, and the disc D is detachably fixed by fitting a center hole into the spindle motor 7.

A swing arm 8 </ b> A is arranged on the side of the spindle motor 7. The swing arm 8 </ b> A includes an arm main body (rotating member) 11 and a bearing device 10.
As shown in FIG. 2, the arm main body 11 protrudes in a direction perpendicular to the axial direction (hereinafter referred to as the axial direction) of the through-hole 12 from the base 11 a in which the through-hole 12 is formed and the axial direction. And a plurality of arm portions 11b arranged at intervals.

The bearing device 10 is disposed coaxially with the through hole 12 in the through hole 12 and supports the arm body 11 so as to be rotatable about the axis of the through hole 12, that is, around the central axis L <b> 1 of the bearing device 10.
As shown in FIG. 1, the base portion 11 a of the arm body 11 is connected to the actuator 6 described above. The arm portion 11b of the arm body 11 extends in parallel with the surface of the disk D, and the head gimbal assembly 4 is connected to the tip thereof. The head gimbal assembly 4 includes a suspension 3 and a slider 2 that is attached to the tip of the suspension 3 and is disposed to face the surface of the disk D. The slider 2 includes a recording element for writing (recording) information on the disk D and a reproducing element for reading (reproducing) information from the disk D.

In the information recording / reproducing apparatus 1 configured as described above, in order to record or reproduce information, first, the spindle motor 7 is driven to rotate the disk D around the central axis L2.
Further, the actuator 6 is driven to rotate the arm body 11 around the central axis L1. As a result, the slider 2 disposed at the tip of the head gimbal assembly 4 can be scanned and moved to each part of the surface of the disk D. Then, by driving the recording element or reproducing element of the slider 2, information can be recorded or reproduced on the disk D.

(First embodiment, swing arm)
As shown in FIG. 2, in the swing arm 8 </ b> A, a step portion 15 that protrudes inward in the radial direction of the through hole 12 is provided at the axial central portion of the inner peripheral surface 12 a of the through hole 12. It has been. In the step portion 15, an annular flat portion 15 a that is orthogonal to the axis of the through hole 12 is formed at portions facing the one side and the other side in the axial direction.
Further, on the inner peripheral surface 12a of the through hole 12, a burr that is continuously depressed over the entire circumference in the circumferential direction of the through hole 12 on the outer peripheral side of the stepped portion 15, that is, on the outer peripheral side of the flat portion 15a. A recess 18 is formed. The burr relief recess 18 is formed such that a burr formed by press-fitting a rolling bearing 30 (described later) into the through hole 12 enters.

  The bearing device 10 is disposed between the shaft 20 inserted into the through hole 12, the inner peripheral surface 12 a of the through hole 12, and the outer peripheral surface 20 a of the shaft 20, and a pair of rolling elements arranged side by side in the axial direction. The bearing 30 (the 1st rolling bearing 31 and the 2nd rolling bearing 32), and the hub cap 80A joined to the shaft 20 and covering the rolling bearing 31 from the outside in the axial direction are provided. The shaft 20, the rolling bearing 30 and the hub cap 80 </ b> A are coaxially arranged on a common shaft, and this common shaft is the central axis L <b> 1 of the bearing device 10.

  In the present application, the inner side in the axial direction of the pair of rolling bearings 31 and 32 (the other rolling bearing side when viewed from one of the pair of rolling bearings 31 and 32) is referred to as “the inner side in the axial direction”. The outer side of the rolling bearings 31 and 32 in the axial direction (the opposite side of the other rolling bearing as viewed from one of the pair of rolling bearings 31 and 32, the side opposite to the stepped portion along the axial direction) Called "outside".

  The shaft 20 is formed in a substantially cylindrical shape from a metal material such as aluminum or stainless steel, and is connected to the housing 9 (see FIG. 1). A flange 25 is formed on one axial side of the shaft 20. Further, the shaft 20 is formed with a concave portion 27 that opens on an end face in the axial direction of the shaft 20. The concave portion 27 penetrates the shaft 20 in the axial direction, and opens individually on both end surfaces of the shaft 20 in the axial direction. The recess 27 is arranged coaxially with the central axis L1. On the inner surface 25a facing the inner side in the axial direction of the flange 25, a ring-shaped convex part 26 protruding toward the inner side in the axial direction is formed along the outer peripheral part of the shaft 20.

The 1st rolling bearing 31 and the 2nd rolling bearing 32 as the rolling bearing 30 are the same shape, and are arrange | positioned by the surface object.
The rolling bearing 30 includes an inner ring 36 fixed to the shaft 20, an outer ring 40 that abuts on the flat surface portion 15 a of the stepped portion 15, a plurality of rolling elements 35 disposed between the inner ring 36 and the outer ring 40, and rolling elements. A retainer 50 that holds the roller 35 in a rollable manner, and a shield (outer shield 60 b) that is disposed on both sides in the axial direction of the rolling element 35 and seals the gap between the inner ring 36 and the outer ring 40.

The inner ring 36 and the outer ring 40 are formed in a substantially cylindrical shape from a metal material.
A rolling groove 38 is formed at the axial center of the outer peripheral surface of the inner ring 36. The rolling groove 38 is formed over the entire circumference of the inner ring 36.
An outer ring main body 45 is formed near the center of the outer ring 40 in the axial direction. A rolling groove 48 is formed at the center in the axial direction of the outer ring 40 on the inner peripheral surface of the outer ring main body 45. The rolling groove 48 is formed over the entire circumference of the outer ring main body 45.
The rolling element 35 is formed in a spherical shape from a metal material. The rolling element 35 is disposed inside each rolling groove 38, 48 and rolls along each rolling groove 38, 48.

  Here, an outer shield holding portion 40b for holding the outer shield 60b is formed outside the outer ring main body portion 45 in the axial direction. On the other hand, a spacer holding portion 40 a that holds a spacer protrusion 72 described later is formed on the inner side of the outer ring main body portion 45 in the axial direction.

  The outer diameter of the outer ring 40 is the same for the entire axial direction of the outer ring 40. On the other hand, the inner diameter of the outer ring 40 is formed such that the inner diameter of the outer ring main body 45 is minimized. The inner diameter of the spacer holding portion 40 a and the inner diameter of the outer shield holding portion 40 b are equal and are formed larger than the inner diameter of the outer ring main body portion 45.

  The outer shield 60 b is disposed on the inner side in the radial direction of the contact portion 63 and the contact portion 63 that contacts the side surface in the axial direction of the outer ring main body 45, and seals the gap between the inner ring 36 and the outer ring 40. A portion 61 and a connecting portion 62 that connects the contact portion 63 and the sealing portion 61 are provided. Further, the outer shield 60 b includes a claw portion 65 erected from the outer periphery of the contact portion 63 in the direction opposite to the rolling element 35. For example, a plurality of claw portions 65 are formed at equal angular intervals in the circumferential direction of the outer shield 60b.

  When the outer shield 60b is press-fitted between the inner ring 36 and the outer ring 40, the claw portion 65 comes into contact with the inner peripheral surface of the outer shield holding portion 40b of the outer ring 40, and the claw portion 65 faces inward in the radial direction of the outer shield 60b. Bends (elastically). Thereby, the outer shield 60b is held on the inner peripheral surface of the outer shield holding portion 40b.

In such a bearing device 10, the first rolling bearing 31 and the second rolling bearing 32 as the rolling bearing 30 are accommodated in the through hole 12 and arranged on both sides in the axial direction with respect to the step portion 15. Yes. Here, the step portion 15 formed on the inner peripheral surface of the through hole 12 has an inner diameter slightly larger than the outer diameter of the inner ring 36 of the rolling bearing 30. Thereby, the rolling bearing 30 is accommodated in the through-hole 12 in a state where only the outer ring 40 is in contact with the flat portion 15 a of the step portion 15.
The shaft 20 is inserted into the inner rings 36 of the first rolling bearing 31 and the second rolling bearing 32 as the rolling bearing 30, and the first rolling bearing 31 is covered from the outside in the axial direction by the flange 25. . At this time, the shaft 20 is disposed in a state where the ring-shaped convex portion 26 of the flange 25 is in contact with the side surface of the inner ring 36 of the first rolling bearing 31. Thus, an axial gap is provided between the outer peripheral portion of the inner surface 25 a of the flange 25 and the outer ring 40 of the first rolling bearing 31.

The hub cap 80A covers the second rolling bearing 32 from the outside in the axial direction (the side opposite to the step portion 15 in the axial direction). The hub cap 80A is formed in a flat plate shape facing the axial direction. The outer diameter of the hub cap 80 </ b> A is equal to the outer diameter of the second rolling bearing 32. A through hole 81 into which the shaft 20 is inserted is formed at the center of the hub cap 80A. The shaft 20 is inserted and fixed in the through hole 81.
The hub cap 80A is fixed to the shaft 20 by press-fitting the shaft 20 into the through hole 81 or by adhering the shaft 20 to the shaft 20 inserted into the through hole 81.
Here, a preload can be applied to the first rolling bearing 31 and the second rolling bearing 32 by the hub cap 80 </ b> A and the shaft 20. By applying the preload, rattling between the inner ring 36 and the outer ring 40 and the rolling element 35 can be suppressed. In the illustrated example, the inner surface 80a of the hub cap 80A is formed by connecting a radially outer relief surface 83 and a radially inner pressing surface 84 via a step surface 85. The flank 83 is formed in an annular shape coaxial with the central axis L1. The pressing surface 84 is provided on a portion of the inner surface 80a of the hub cap 80A that is located on the radially inner side of the clearance surface 83 and on the radially outer side of the through hole 81. The pressing surface 84 is located on the inner side in the axial direction than the flank 83. The step surface 85 is located on the outer side in the radial direction from the inner ring 36 and on the inner side in the radial direction from the outer ring 40.
In the hub cap 80A, the pressing surface 84 presses the inner ring 36 of the second rolling bearing 32 toward the inner side in the axial direction. The pressing surface 84 is separated from the end surface of the shaft 20 in the axial direction. Further, the flank 83 is separated from the end surface of the outer ring 40 in the axial direction.

(How to assemble the swing arm)
The swing arm 8A provided with the bearing device 10 as described above is assembled as follows.
First, the first rolling bearing 31 is incorporated into the shaft 20. At this time, the shaft 20 and the inner ring 36 of the first rolling bearing 31 may be joined by press-fitting or bonding.
Next, the shaft 20 incorporating the first rolling bearing 31 is press-fitted into the through hole 12 of the arm body 11 from one side in the axial direction, and the first rolling bearing 31 is brought into contact with the flat portion 15 a of the step portion 15.
Next, the second rolling bearing 32 is press-fitted into the through hole 12 from the other side in the axial direction and brought into contact with the flat surface portion 15 a of the step portion 15.
Subsequently, the hub cap 80 </ b> A is attached by inserting the shaft 20 into the through hole 81. At this time, it is also possible to apply preload to the first rolling bearing 31 and the second rolling bearing 32 via the ring-shaped convex portion 26 and the pressing surface 84 by pressing the hub cap 80A inward in the axial direction. When the hub cap 80A is bonded to the shaft 20, an adhesive is applied to at least one of the shaft 20 and the hub cap 80A, and a predetermined preload is applied to the first rolling bearing 31 and the second rolling bearing 32. Allow the adhesive to cure.
Thereby, the assembly of the swing arm 8A provided integrally with the bearing device 10 is completed.

As described above, according to the assembly method of the swing arm 8A and the swing arm 8A according to the present embodiment, the first rolling bearing 31 and the second rolling bearing 32 as the pair of rolling bearings 30 are Therefore, the pair of first rolling bearing 31 and second rolling bearing 32 can be inserted into the step portion 15 from both sides in the axial direction. Thereby, the distance by which each of the 1st rolling bearing 31 and the 2nd rolling bearing 32 is press-fit can be shortened, and the 1st rolling bearing 31 and the 2nd rolling bearing 32 become difficult to incline. Further, the shorter the press-fitting distance, the lower the possibility that the burr will bite. Therefore, the force acting between the inner peripheral surface of the through hole 12 and the outer peripheral surfaces of the first rolling bearing 31 and the second rolling bearing 32 is prevented from varying at each position along the circumferential direction of the through hole 12. It is possible to prevent the axial lines of the first rolling bearing 31 and the second rolling bearing 32 from being displaced.
Further, by inserting the pair of first rolling bearing 31 and second rolling bearing 32 from both sides in the axial direction with respect to the stepped portion 15, either one of the first rolling bearing 31 and the second rolling bearing 32 is inserted. An increase in stroke can be avoided, and the first and second rolling bearings 31 and 32 can have the same insertion stroke into the through hole 12. Thereby, it can suppress that a torque differs with the 1st rolling bearing 31 and the 2nd rolling bearing 32. FIG.
Further, it is not necessary to fix the first rolling bearing 31 and the second rolling bearing 32 by using an adhesive or a tolerance ring, and in this respect also, the inner peripheral surface of the through hole 12, the first rolling bearing 31 and the second rolling bearing 31 are not required. It is possible to suppress the force acting between the outer peripheral surface of the rolling bearing 32 from being varied for each position along the circumferential direction of the through hole 12 and to suppress the generation of torque waves as described above. .

  In addition, since the burr escape recess 18 is formed on the outer peripheral side of the stepped portion 15, even if a burr is formed when the first rolling bearing 31 and the second rolling bearing 32 are press-fitted into the through hole 12, This burr can enter the burr escape recess 18 to prevent the burr from being caught between the first rolling bearing 31 and the second rolling bearing 32 and the through hole 12. Also by this, the force acting between the inner peripheral surface of the through-hole 12 and the outer peripheral surfaces of the first rolling bearing 31 and the second rolling bearing 32 varies from position to position along the circumferential direction of the through-hole 12. And the occurrence of torque waves can be suppressed.

In addition, since the preload can be applied later to the first rolling bearing 31 and the second rolling bearing 32 inserted into the through hole 12 by the hub cap 80A, the preload can be controlled with high accuracy, and the preload can be controlled. After the application, an unexpected torque increase can be suppressed.
Further, the first rolling bearing 31 and the second rolling bearing 32 are fixed by being sandwiched between the step portion 15, the flange 25 of the shaft 20, and the hub cap 80 </ b> A in the axial direction. Therefore, the first rolling bearing 31 and the second rolling bearing 32 do not need to be fixed to the through hole 12 with strong tension in the radial direction, and may be lightly press-fitted into the through hole 12. As a result, even when the first rolling bearing 31 and the second rolling bearing 32 are preloaded, it is possible to prevent the preload from being influenced by the force acting from the radially outer peripheral side, and the preload can be accurately performed. I can control it.
Further, since the hub cap 80A applies preload to the first rolling bearing 31 and the second rolling bearing 32, it is possible to apply preload to the rolling bearing 30 by joining the hub cap 80A to the shaft 20. Thus, it is possible to eliminate the need for a separate preload operation. Thereby, simplification of manufacture of this swing arm 8A can be achieved.

  In addition, since the shaft 20 in which the first rolling bearing 31 is incorporated is inserted into the through hole 12, the first rolling bearing 31 can be smoothly press-fitted into the through hole 12, and the swing arm 8A can be mounted. Easy to assemble.

  In the present embodiment, only the outer shield 60b is provided as a shield, but the present invention is not limited to this. For example, in addition to the outer shield, an inner shield provided inside the outer ring main body in the axial direction may be provided. In this case, since the gap between the inner ring and the outer ring is closed, it is possible to prevent the grease filled in the gap from flowing out. As a result, the rolling bearing does not burn and smooth rotation is not impossible, and the performance of the rolling bearing can be ensured. Further, it is possible to prevent the leaked grease from adhering to the surface of the magnetic recording medium and causing a writing error or a reading error. Furthermore, since the gap between the inner ring and the outer ring is closed, it is possible to prevent dust from entering the gap. Thereby, smooth rotation of the rolling bearing does not become impossible, and the performance of the rolling bearing can be ensured. For example, the inner shield may be formed in the same shape as the outer shield.

(Modification of the first embodiment)
In the method of assembling the swing arm 8A shown in the first embodiment, the hub cap 80A is pressurized inward in the axial direction so that preload is applied to the first rolling bearing 31 and the second rolling bearing 32. However, it is not limited to this.
Prior to mounting the hub cap 80A, the hub cap 80A may be mounted after applying a predetermined preload to the second rolling bearing 32 disposed in the through hole 12 via a jig or the like. In this case, the second rolling bearing 32 is fixed to the through hole 12 by press fitting or adhesion.
Furthermore, in the configuration in which a predetermined preload is applied to the second rolling bearing 32 through a jig or the like and the second rolling bearing 32 is fixed to the through-hole 12 by press-fitting or bonding, a hub cap is provided. The mounting of 80A may be omitted.

Moreover, in the said 1st Embodiment, although the burr | flash relief recessed part 18 was formed so that it might be depressed in the radial direction outer side from the internal peripheral surface 12a of the through-hole 12, it does not restrict to this.
For example, as shown in FIG. 3, the burr escape recess 18 may be formed on the flat portion 15 a of the step portion 15 so as to be continuous with the inner peripheral surface 12 a of the through hole 12 toward the inner side in the axial direction.
Further, as shown in FIG. 4, the burr relief recess 18 is a surface that is located on the inner side in the axial direction and faces the flat portion 15 a of the step portion 15 in the outer ring 40 of the first rolling bearing 31 and the second rolling bearing 32. You may form in the outer peripheral edge part so that it may dent in the radial inside.

(Second Embodiment)
FIG. 5 is a side sectional view of the swing arm according to the second embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.
In the swing arm 8B according to the present embodiment, the step portion 15 is positioned inside the range where the plurality of arm portions 11b of the arm body 11 are provided in the axial direction. The base portion 11a of the arm body 11 is formed with a slit portion 96 that opens into a space S formed between the arm portions 11b and 11b that face each other in the axial direction. The slit portion 96 extends toward the radially inner peripheral side of the base portion 11 a, and the inner peripheral end portion 96 b is formed up to the vicinity of the inner peripheral side end portion 15 b of the stepped portion 15.

In the information recording / reproducing apparatus 1 (see FIG. 1) provided with such a swing arm 8B, the torque wave can be prevented and the preload can be controlled with high accuracy and the quality can be improved as in the first embodiment. it can.
Furthermore, in the information recording / reproducing apparatus 1 provided with the swing arm 8B of the present embodiment, it is possible to have a layout in which the disc D is inserted not only to the space S between the arm portions 11b and 11b but also to the slit portion 96. . Thereby, the swing arm 8B can be shortened, and the information recording / reproducing apparatus 1 can also be reduced in size.
In addition, by shortening the swing arm 8B, the swing speed of the swing arm 8B can be increased, and the operation of the information recording / reproducing apparatus 1 can be increased.

(Third embodiment)
FIG. 6 is an enlarged cross-sectional view of a main part of a swing arm according to the third embodiment. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.
In the swing arm 8C of the present embodiment, the hub cap 80C is provided with an insertion portion 82 to be inserted into the concave portion 27 of the shaft 20, instead of providing the through hole 81. The insertion portion 82 projects from the hub cap 80C toward the inside in the axial direction. The insertion portion 82 is disposed coaxially with the central axis L <b> 1 and is press-fitted into the recess 27. Thereby, the hub cap 80 </ b> C is joined to the shaft 20 via the insertion portion 82.

  In the hub cap 80 </ b> C, an axial gap is provided between the inner surface 80 a facing the inner side in the axial direction and the end surface of the shaft 20. The hub cap 80 </ b> C applies a preload to the rolling bearing 30. The hub cap 80 </ b> C applies a preload to the second rolling bearing 32 by pressing the inner ring 36 toward the inner side in the axial direction of the second rolling bearing 32.

  In the illustrated example, the inner surface 80 a of the hub cap 80 </ b> C is formed by connecting a radially outer relief surface 91 and a radially inner pressing surface 92 via a step surface 93. The flank 91 is formed in an annular shape coaxial with the central axis L1. The pressing surface 92 is provided on a portion of the inner surface 80a of the hub cap 80C that is located on the inner side in the radial direction than the flank 91. The pressing surface 92 is located on the inner side in the axial direction than the flank 91. The step surface 93 is located on the outer side in the radial direction from the inner ring 36 and on the inner side in the radial direction from the outer ring 40.

  In the hub cap 80C, the pressing surface 92 presses the inner ring 36 of the second rolling bearing 32 toward the inner side in the axial direction. The pressing surface 92 is separated from the end surface of the shaft 20 in the axial direction. The flank 91 is spaced apart from the end surface of the outer ring 40 in the axial direction.

As described above, according to the swing arm 8C according to the present embodiment, the torque wave can be prevented, the preload can be controlled with high accuracy, and the quality can be improved, as in the first embodiment.
Furthermore, according to the swing arm 8C according to the present embodiment, since the hub cap 80C is joined to the shaft 20 via the insertion portion 82, the shaft 20 is maintained in the axial direction while maintaining the axial size of the shaft 20. Each of the recessed portion 27 and the insertion portion 82 of the hub cap 80C can be formed long in the axial direction. Therefore, it is possible to ensure a long stroke in the axial direction when inserting the insertion portion 82 into the concave portion 27 and to increase the insertion allowance for the concave portion 27 of the insertion portion 82. As a result, the hub cap 80C can be assembled to the shaft 20 with high accuracy and firmly bonded while suppressing an increase in size of the bearing device 10.

  Since the recess 27 penetrates the shaft 20 in the axial direction, the hub cap 80C is inserted into the shaft 20 by press-fitting the insertion portion 82 into the recess 27 from the other side in the axial direction, for example, as in this embodiment. In the configuration to be fixed, when the hub cap 80C is desired to be detached from the shaft 20 after the insertion portion 82 is press-fitted into the recess 27, the insertion portion 82 can be pushed away from one side in the axial direction. . Therefore, the hub cap 80C can be detached from the shaft 20 without affecting the quality of the rolling bearing 30, and the yield of the bearing device 10 can be improved.

(Fourth embodiment)
FIG. 7 is an enlarged cross-sectional view of a main part of a swing arm according to the fourth embodiment. In the fourth embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  In the swing arm 8D according to the fourth embodiment, the rolling element 35 is exposed from the inner side in the axial direction through the space between the inner ring 36 and the outer ring 40 with respect to the hub cap 80C, and is not provided with a shield. In the illustrated example, the outer shield of the second rolling bearing 32 and the outer shield of the first rolling bearing 31 are not provided. Accordingly, the rolling elements 35 of the first rolling bearing 30 are exposed from the inner side in the axial direction through the space between the inner ring 36 and the outer ring 40 with respect to the flange 25 of the shaft 20.

  As described above, according to the swing arm according to the present embodiment, the rolling element 35 is exposed from the inner side in the axial direction through the space between the inner ring 36 and the outer ring 40 with respect to the hub cap 80C. As in the third embodiment, the configuration is such that the rolling bearing 30 is provided with a shield that is arranged outside the rolling element 35 in the axial direction and seals the gap between the inner ring 36 and the outer ring 40 (see FIG. 6). In comparison, the rolling bearing 30 can be formed smaller in the axial direction. Thereby, size reduction of the bearing apparatus 10 can be achieved.

  In the present embodiment, the pressing surface 92 presses the inner ring 36 of the second rolling bearing 32 toward the inner side in the axial direction, and the pressing surface 92 contacts the inner ring 36 from the outer side in the axial direction. The size of the step surface 93 of the hub cap 80C in the axial direction can be minimized by dimensional management. That is, since the pressing surface 92 is in contact with the inner ring 36 from the outside in the axial direction, the axial distance between the flank 91 and the rolling bearing 30 is set based on the axial size of the step surface 93. Can do. Therefore, by appropriately designing the size of the stepped surface 93 in the axial direction, the clearance surface 91 can be reliably separated from the end surface of the outer ring 40 in the axial direction, and the distance between the two can be kept to a minimum. As a result, the gap between the inner ring 36 and the outer ring 40 can be reliably sealed in the hub cap 80C and the flange 25, and the function of the shield can be substituted with high accuracy in the hub cap 80C.

It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific materials and structures described in the embodiments are merely examples, and can be changed as appropriate.
For example, the relief surface is formed on the inner surface of the hub cap, but the present invention is not limited to this. For example, by forming the inner surface of the hub cap flush and pressing the inner ring against the inner surface, the end surface on the outer side in the axial direction of the outer ring is positioned more on the inner side in the axial direction than the end surface of the inner ring. You may employ | adopt the structure which does not press an outer ring | wheel on an inner surface.
Further, for example, the specific configuration of the information recording / reproducing apparatus is not limited to the configuration of the embodiment. Further, the specific shape of the shaft of the bearing device is not limited to the shape of the embodiment. In the embodiment, the outer shield of the rolling bearing is fixed to the outer ring, but may be fixed to the inner ring. Further, in the embodiment, the recess penetrates the shaft in the axial direction, but it does not have to penetrate. In the embodiment, the insertion portion is press-fitted into the recess, but the present invention is not limited to this. For example, the insertion portion may be loosely fitted in the recess, and the outer peripheral surface of the insertion portion and the inner peripheral surface of the recess may be bonded. Moreover, while forming an external thread in the outer peripheral surface of an insertion part, forming an internal thread in the internal peripheral surface of a recessed part, you may screw an insertion part in a recessed part. Further, in the embodiment, a plurality of arm portions are disposed on the base portion at intervals in the axial direction. However, the present invention is not limited to this, and for example, one arm portion may be provided.

DESCRIPTION OF SYMBOLS 1 Information recording / reproducing apparatus 2 Slider 8A-8D Swing arm 9 Housing 10 Bearing apparatus 11 Arm main body (rotating member)
11a Base portion 11b Arm portion 12 Through hole 12a Inner peripheral surface 15 Stepped portion 18 Burr relief recess 20 Shaft 20a Outer peripheral surface 25 Flange 30 Rolling bearing 31 First rolling bearing 32 Second rolling bearing 35 Rolling element 36 Inner ring 40 Outer ring 80A Hub cap 80C Hub cap 82 Insertion part 96 Slit part D Disk (magnetic recording medium)

Claims (10)

A rotating member having a base portion formed with a through hole and an arm portion protruding from the base portion;
A swing arm for an information recording / reproducing apparatus, comprising: a bearing device disposed in a through hole formed in the base and supporting the rotating member so as to be rotatable about an axis of the through hole;
On the inner peripheral surface of the through hole, a stepped portion protruding toward the inner side in the radial direction of the through hole is provided in the central portion of the through hole in the axial direction.
The bearing device includes a shaft inserted into the through hole, and a pair of rolling bearings press-fitted between an inner peripheral surface of the through hole and an outer peripheral surface of the shaft,
The pair of rolling bearings are arranged on both sides in the axial direction with respect to the stepped portion. The swing arm according to claim 1,
At least one of the inner peripheral surface of the through hole and the outer peripheral surface of the rolling bearing is provided with a burr escape recess into which a burr formed by press-fitting the rolling bearing into the through hole enters. Swing arm characterized by that. The swing arm according to claim 2,
The burr escape recess is a swing arm characterized in that, of the inner peripheral surface of the through hole, a connection portion with the stepped portion is recessed outward in the radial direction. The swing arm according to any one of claims 1 to 3,
A plurality of the arm portions are disposed on the base portion at intervals in the axial direction,
At least some of the stepped portions are located on the inner side in the axial direction of the plurality of arm portions,
The base is formed with a slit portion that opens between the arm portions adjacent in the axial direction,
An end of the slit portion on the inner side in the radial direction is located in the stepped portion. The swing arm according to any one of claims 1 to 4,
The bearing device includes a hub cap that covers the rolling bearing from the opposite side of the step along the axial direction.
The hub arm is a swing arm in which a preload is applied to the rolling bearing. The swing arm according to claim 5,
The shaft is formed with a recess opening in the axial end surface of the shaft,
The swing arm is characterized in that the hub cap is joined to the shaft via an insertion portion provided in the hub cap and inserted into the recess. A swing arm according to claim 1;
A housing connected to the shaft;
A slider mounted on the rotating member, for recording and reproducing information on a magnetic recording medium;
An information recording / reproducing apparatus comprising: A rotating member having a base portion formed with a through hole and an arm portion protruding from the base portion;
A bearing device that is disposed in a through hole formed in the base and supports the rotating member so as to be rotatable around an axis of the through hole;
The bearing device is for an information recording / reproducing apparatus comprising: a shaft inserted into the through hole; and a pair of rolling bearings press-fitted between an inner peripheral surface of the through hole and an outer peripheral surface of the shaft. A swing arm assembly method for forming a swing arm,
A method for assembling a swing arm, comprising a step of press-fitting the pair of rolling bearings into the through-holes from both sides in the axial direction of the through-holes. A method for assembling a swing arm according to claim 8,
A swing arm assembling method comprising a preloading step of applying a preload to the rolling bearing press-fitted into the through hole. A method for assembling a swing arm according to claim 8 or 9,
The press-fitting process includes
The shaft incorporating the first rolling bearing, which is one of the pair of rolling bearings, is inserted into the through hole from one side in the axial direction with respect to the through hole, and the first rolling bearing is inserted into the through hole. Press-fitting process;
And a step of press-fitting a second rolling bearing, which is the other of the pair of rolling bearings, into the through-hole from the other side in the axial direction with respect to the through-hole.

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