Motor and rotary drive device

Abstract

To provide a structure in which machining oil used for finishing a sleeve and a case in a motor hardly penetrates between the case and a sleeve component.SOLUTION: A spindle motor 3 includes a sleeve 40 formed in a tubular shape extending in an axial direction, a case 50 formed in a tubular shape extending in the axial direction and disposed on an outer side in a radial direction orthogonal to the axial direction so as to be in contact with an 41b of an outer peripheral surface of the sleeve 40, and a protruding portion 42 provided on at least one of the sleeve 40 and the case 50 at a contact portion 70 between the sleeve 40 and the case 50.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a motor and a rotary drive device. [Background technology]

[0002] A type of spindle motor with a rotating shaft is known (see, for example, Patent Document 1). In this type of spindle motor, the shaft is supported by the inner circumferential surface of a cylindrical sleeve part press-fitted into a cylindrical case. Lubricating oil is filled between the sleeve part and the shaft, and when the shaft rotates, it functions as a fluid dynamic bearing.

[0003] The end of the sleeve component faces the rotor hub and the flange of the shaft, which are rotating components, so high surface accuracy is required. Therefore, the sleeve component is subjected to finishing after being press-fitted into the case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-200583 Summary of the Invention [Problem to be solved by the invention]

[0005] During the finishing process, processing oil is used in the processing area. Processing oil can seep into the gap between the case and the sleeve component, and can leak out over time. If the leaked processing oil passes through the upper end surface of the sleeve and mixes with the lubricating oil filled between the sleeve component and the shaft, it can deteriorate the lubricating oil.

[0006] An object of the present invention is to provide a structure in which processing oil used during finish processing of the sleeve and case in a motor is less likely to seep into the gap between the case and sleeve components. [Means for solving the problem]

[0007] In order to solve the above problems, there is provided a motor comprising a first member formed in a cylindrical shape extending in an axial direction, a second member formed in a cylindrical shape extending in the axial direction and arranged radially outwardly perpendicular to the axial direction so as to contact the outer peripheral surface of the first member, and a protrusion provided on at least one of the first member and the second member at a contact portion between the first member and the second member, wherein the contact portion has a first region intersecting the axial direction, the protrusion is provided in the first region, and the first member is press-fitted into the second member. [Effects of the Invention]

[0008] According to the present invention, the processing oil used in finishing the sleeve and case of the motor is less likely to seep into the gap between the case and sleeve components. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a hard disk drive device 1. [Figure 2] FIG. 2 is a partial cross-sectional view of the spindle motor 3. [Figure 3] FIG. 3 is an enlarged view of part III in FIG. 2. [Figure 4] FIG. 10 is a partial cross-sectional view of a spindle motor 3 according to a modified example. [Figure 5] FIG. 5 is an enlarged view of a portion V in FIG. [Figure 6] FIG. 10 is a partial cross-sectional view of a spindle motor 3 according to a modified example. [Figure 7] FIG. 10 is a partial cross-sectional view of a spindle motor 3 according to a modified example. [Figure 8] FIG. 8 is an enlarged view of part VIII in FIG. 7. [Figure 9] FIG. 10 is a partial cross-sectional view of a spindle motor 3 according to a modified example. [Figure 10] FIG. 10 is an enlarged view of the X portion of FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, although the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0011] Fig. 1 is a perspective view showing the configuration of a hard disk drive device 1. Fig. 2 is a partial cross-sectional view showing an example of a spindle motor 3 used in the hard disk drive device 1.

[0012] 2 and other figures, the direction parallel to the central axis of shaft 80 (described later) is referred to as the axial direction, the direction around the central axis of shaft 80 as the circumferential direction, and the direction perpendicular to the axial direction as the radial direction. For the sake of explanation, the axial direction is referred to as the up-down direction, and the rotating part 20 side relative to the stationary part 10 is referred to as the top, and the stationary part 10 side is referred to as the bottom.

[0013] <Hard disk drive> The hard disk drive device 1 (an example of a rotary drive device) includes a housing 2, a spindle motor 3, a recording disk 4, and a bearing device 5.

[0014] The housing 2 includes a case 6 and a cover 7. The case 6 has a box-like shape that is roughly rectangular and has one open side and a bottom. The cover 7 is a plate-like member that closes the open side of the case 6. The cover 7 is fastened to the case 6 using screws 7A. A sealing means (not shown) is provided between the case 6 and the cover 7, and thus the cover 7, together with the case 6, form the housing 2 having a sealed internal space S.

[0015] The internal space S of the housing 2 is filled with air or helium gas, which has a lower density than air. In addition to air or helium gas, the internal space S may also be filled with, for example, nitrogen gas or a mixed gas of helium and nitrogen. The internal space S accommodates a spindle motor 3, a recording disk 4, and a bearing device 5.

[0016] The spindle motor 3 (an example of a motor) rotatably supports a plurality of recording disks 4. The detailed structure of the spindle motor 3 will be described later.

[0017] A plurality of recording disks 4 are provided and supported by the spindle motor 3 so that the disk surfaces face each other. A gap is formed between each of the recording disks 4.

[0018] The bearing device 5 swingably supports a plurality of swing arms 8 that are disposed in the gaps between the respective recording disks 4.

[0019] The swing arm 8 has a magnetic head 9 at its tip. The magnetic head 9 applies magnetism to the recording disk 4 and reads magnetism from the recording disk 4. When the swing arm 8 swings, the magnetic head 9 moves over the recording disk 4.

[0020] When the spindle motor 3 rotates, the recording disk 4 also rotates. In this state, when the swing arm 8 swings, the magnetic head 9 moves over the rotating recording disk 4. The magnetic head 9 then applies magnetism to the recording disk 4 and records data on the recording disk 4. The magnetic head 9 also reads magnetism from the recording disk 4 and reads out the data stored on the recording disk 4.

[0021] <Spindle motor> Next, we will explain the detailed configuration of the spindle motor 3. Figure 2 is a partial cross-sectional view showing the configuration of the spindle motor 3. The spindle motor 3 includes a stationary part 10 and a rotating part 20 that rotates relative to the stationary part 10 via a bearing mechanism.

[0022] (Stationary part) The stationary portion 10 includes a base plate 30 , a bearing sleeve 40 , a case 50 , and a stator core 60 .

[0023] The base plate 30 is a metal member and has a through hole 31, a circumferential groove 32, and a circumferential wall 33 formed therein.

[0024] The through hole 31 is a hole for fixing the case 50. The through hole 31 is provided so as to pass through the base plate 30 in the axial direction. The through hole 31 is cylindrical, and the inner diameter of the cylinder is approximately the same as or larger than the outer diameter of the case 50.

[0025] The circumferential groove portion 32 is formed radially outward of the through hole 31. The circumferential groove portion 32 is an annular groove provided so as to be coaxial with the central axis of the through hole 31 when viewed in the axial direction.

[0026] The circumferential wall portion 33 is formed as an annular wall surface portion that protrudes axially upward from the bottom surface of the circumferential groove portion 32 when viewed in the axial direction. The diameter of the circumferential wall portion 33 is larger than the diameter of the through hole 31.

[0027] The bearing sleeve 40 (an example of a first member) rotatably supports the shaft 80. The bearing sleeve 40 is a cylindrical brass member extending in the axial direction. The outer circumferential surface of the bearing sleeve 40 is machined. The bearing sleeve 40 has a main body 41, a protrusion 42, and a through hole 43.

[0028] The main body 41 is a cylindrical member extending in the axial direction. The main body 41 has an inner circumferential surface 41a, an outer circumferential surface 41b, and an upper end portion 44. The inner circumferential surface 41a faces the shaft 80, and the outer circumferential surface 41b faces the case 50.

[0029] The protrusion 42 is a member provided radially outward from the main body 41. As shown in Figures 3 and 4, the protrusion 42 protrudes radially outward from the outer circumferential surface of the main body 41. The protrusion 42 is provided radially outward from the upper end 44, and is provided around the entire circumferential circumference of the upper end 44. The outer diameter of the outer circumferential surface of the protrusion 42 is tapered, decreasing from top to bottom. The taper angle θ of the outer diameter of the outer circumferential surface of the protrusion 42 (the angle at which it intersects with the axial direction; see Figure 3) is preferably 30 degrees or more and 60 degrees or less. The outer circumferential surface of the protrusion 42 may be tapered, flat, or curved.

[0030] The through hole 43 is a hole formed on the radially inner side of the main body portion 41. The through hole 43 is formed so as to penetrate the main body portion 41 in the axial direction when viewed in the axial direction.

[0031] The case 50 (an example of a second member) holds the bearing sleeve 40 and is fixed to the base plate 30. The case 50 is a cylindrical member made of iron, such as stainless steel, that extends in the axial direction. The outer circumferential surface of the case 50 is machined. The bearing sleeve 40 is press-fitted into the inside of the case 50. In other words, the case 50 is disposed radially outside the bearing sleeve 40. The case 50 has a case main body 51, a through hole 52, a lower end recess 53, and an upper end recess 54.

[0032] The case main body 51 is a cylindrical member extending in the axial direction. The case main body 51 has an inner peripheral surface 51a and an outer peripheral surface 51b. The inner peripheral surface 51a faces and contacts the outer peripheral surface 41b of the main body 41, and the outer peripheral surface 51b faces the inner peripheral surface of the through hole 31 of the base plate 30.

[0033] The through hole 52 is a hole formed radially inward of the case main body 51. When viewed in the axial direction, the through hole 52 is formed so as to penetrate the case main body 51 in the axial direction. The bearing sleeve 40 is inserted into the through hole 52. The through hole 52 is continuous with the lower end recess 53.

[0034] The lower end recess 53 is a recess provided at the lower end of the case main body 51. The lower end recess 53 is a cylindrical space provided so as to be coaxial with the central axis of the through hole 52 when viewed in the axial direction. The lower end recess 53 opens downward. The diameter of the lower end recess 53 is larger than the diameter of the through hole 52. A counter plate 55 is attached to the lower end recess 53.

[0035] The counter plate 55 is a disk-shaped lid that is inserted into the lower end recess 53 from below the case main body 51. The counter plate 55 closes the lower end recess 53.

[0036] The upper-end recess 54 is a recess provided at the upper end of the case main body 51. The upper-end recess 54 is provided coaxially with the center axis of the through hole 52 when viewed in the axial direction and is connected to the through hole 52. The upper-end recess 54 is tapered at the upper end of the case main body 51, with the inner diameter decreasing from top to bottom. That is, the inner diameter of the inner circumferential surface of the upper-end recess 54 is tapered from top to bottom. The taper angle θ (the angle intersecting the axial direction; see FIG. 3 ) of the inner diameter of the inner circumferential surface of the upper-end recess 54 is smaller than the taper angle of the outer diameter of the outer circumferential surface of the protrusion 42. The taper angle of the inner diameter of the inner circumferential surface of the upper-end recess 54 is preferably 30 degrees or more and 60 degrees or less. The inner circumferential surface of the upper-end recess 54 may be tapered, flat, or curved.

[0037] The relationship between the base plate 30, the bearing sleeve 40, and the case 50 will now be described. The bearing sleeve 40 is press-fitted into the case body 51 from above in the axial direction so that the outer peripheral surface 41b of the main body 41 faces the inner peripheral surface 51a of the case body 51. At this time, the bearing sleeve 40 is press-fitted until the outer peripheral surface of the protrusion 42 contacts the upper-end recess 54 of the case body 51. Here, because the taper angle of the inner diameter of the inner peripheral surface of the upper-end recess 54 is smaller than the taper angle of the outer diameter of the outer peripheral surface of the protrusion 42, the protrusion 42 and the upper-end recess 54 first contact each other at their radially outermost locations. When the bearing sleeve 40 is further press-fitted downward, a force is generated that causes the outer peripheral surface of the protrusion 42 to press against the inner peripheral surface of the upper-end recess 54 in the axial direction. Therefore, the bearing sleeve 40 is press-fitted into the case 50 while the protrusion 42 deforms the upper-end recess 54. As a result, the protrusion 42 and the upper end recess 54 form a contact area from the outside to the inside in the radial direction. In this way, the bearing sleeve 40 and the case 50 are joined together.

[0038] By press-fitting the bearing sleeve 40 into the case 50, a contact portion 70 is formed between the two components. The contact portion 70 has a first region 71 where the protrusion 42 and the upper-end recess 54 are in contact in a direction intersecting the axial direction, and a second region 72 where the main body 41 and the case main body 51 are in contact in the axial direction. The first region 71 and the second region 72 are continuous at a lower end 71b of the first region 71 and an upper end 72a of the second region 72.

[0039] When the bearing sleeve 40 is joined to the case 50, the lower end of the main body 41 is spaced axially upward from the upper surface of the counter plate 55. A shaft flange 82 of the shaft 80, which will be described later, is disposed between the lower end of the main body 41 and the upper surface of the counter plate 55.

[0040] In the case of a bearing sleeve and case of a conventional structure, after the bearing sleeve is press-fitted into the case, the upper and lower end surfaces of the bearing sleeve and case are subjected to a finishing process (e.g., grinding). Therefore, the processing oil used during the finishing process can seep into the gap at the joint between the bearing sleeve and the case. However, in this embodiment, the bearing sleeve 40 has the protrusion 42 pressing against the upper-end recess 54 in the axial direction, deforming it. Therefore, the gap at the joint between the protrusion 42 and the upper-end recess 54 is extremely small. Therefore, when the upper end surfaces of the bearing sleeve 40 and the case 50 are finished using processing oil, the processing oil is less likely to seep into the gap at the joint between the protrusion 42 and the upper-end recess 54.

[0041] The case 50 to which the bearing sleeve 40 is joined is inserted into the through hole 31 so that the outer peripheral surface 51b of the case main body 51 faces the inner peripheral surface of the through hole 31 in the base plate 30. The case 50 is inserted into the through hole 31 with adhesive applied to one or both of the outer peripheral surface 51b and the inner peripheral surface of the through hole 31, and is fixed to the through hole 31 as the adhesive hardens.

[0042] The stator core 60 is a member formed by laminating multiple annular electromagnetic steel plates in the axial direction when viewed in the axial direction. The stator core 60 is placed inside the circumferential groove portion 32 and fixed by a method such as adhesive. The stator core 60 has multiple pole teeth (salient poles) that extend radially outward and are arranged along the circumferential direction. Coils 61 are wound around the pole teeth. The stator core 60 generates magnetic flux when a current flows through the coils 61.

[0043] (rotating part) The rotating part 20 has a shaft 80 , a rotor hub 90 , and a rotor magnet 100 .

[0044] The shaft 80 is a member that serves as the rotating shaft of the spindle motor 3. The shaft 80 is rotatably supported inside the bearing sleeve 40. The shaft 80 has a columnar shaft portion 81 and a shaft flange portion 82. The shaft 80 has the shaft portion 81 and the shaft flange portion 82 integrated together.

[0045] The shaft portion 81 is a cylindrical shaft member. A shaft flange portion 82 is integrally formed with a lower shaft end portion 83 of the shaft portion 81. The shaft portion 81 is disposed inside the bearing sleeve 40 so that the shaft end portion 83 with the shaft flange portion 82 is on the lower side. In other words, the outer peripheral surface of the shaft portion 81 is surrounded by the inner peripheral surface 41a of the main body portion 41. The outer peripheral surface of the shaft portion 81 and the inner peripheral surface 41a face each other with a small gap between them. A radial dynamic pressure generating groove 84 is formed on the outer peripheral surface of the shaft portion 81.

[0046] The radial dynamic pressure generating grooves 84 are provided on the outer peripheral surface of the shaft portion 81. In this embodiment, the radial dynamic pressure generating grooves 84 are formed in a continuous row in the circumferential direction on the outer peripheral surface of the shaft portion 81, and are formed in two rows spaced apart in the axial direction.

[0047] The shaft flange portion 82 is an annular flange member that expands radially when viewed in the axial direction. The shaft flange portion 82 is joined to the shaft end portion 83 and is integral with the shaft portion 81. The outer diameter of the shaft flange portion 82 is smaller than the inner diameter of the case main body portion 51. Thrust dynamic pressure generating grooves 85 are formed on the upper and lower surfaces of the shaft flange portion 82, respectively.

[0048] The thrust dynamic pressure generating groove 85 is provided on the upper and lower surfaces of the shaft flange portion 82. The thrust dynamic pressure generating groove 85 is provided in an annular shape so as to be coaxial with the central axis of the shaft flange portion 82 when viewed in the axial direction.

[0049] When the shaft 80 is supported by the bearing sleeve 40, the shaft flange portion 82 is disposed between the lower end of the main body portion 41 and the upper surface of the counter plate 55. The upper surface of the shaft flange portion 82 faces the annular surface 46, which is the axially lower end surface of the main body portion 41, across a small gap. The lower surface of the shaft flange portion 82 faces the upper surface of the counter plate 55 across a small gap. The side surface of the shaft flange portion 82 faces the inner circumferential surface 51a of the case main body portion 51 across a small gap. By disposing the shaft flange portion 82 between the annular surface 46 and the counter plate 55, axial movement of the shaft 80 is prevented.

[0050] Lubricating oil is filled between the shaft 80 and the bearing sleeve 40 and between the shaft 80 and the case 50. Specifically, the lubricating oil is filled between the outer peripheral surface of the shaft portion 81 and the inner peripheral surface 41a of the main body portion 41, between the upper surface of the shaft flange portion 82 and the annular surface 46, between the lower surface of the shaft flange portion 82 and the upper surface of the counter plate 55, and between the side surface of the shaft flange portion 82 and the inner peripheral surface 51a of the case main body portion 51.

[0051] The rotor hub 90 is a member that rotates together with the shaft 80. The rotor hub 90 is attached to the upper end of the shaft 80 and is connected to the shaft 80. The rotor hub 90 has a disk portion 91, a cylindrical portion 92, and an outer edge portion 93.

[0052] The disk portion 91 is a disk-shaped member that is coaxial with the central axis of the shaft 80 when viewed in the axial direction. The disk portion 91 has a rotor hub through hole 94. The rotor hub through hole 94 is provided at the center of the disk portion 91 when viewed in the axial direction. The disk portion 91 is fixed to the shaft 80. Specifically, the upper end of the shaft 80 is inserted into the rotor hub through hole 94, and the disk portion 91 is fixed by a method such as press-fitting or adhesive bonding, thereby fixing the disk portion 91 to the shaft 80.

[0053] The cylindrical portion 92 is a cylindrical member having a thickness in the radial direction. The cylindrical portion 92 is arranged so as to be coaxial with the center axis of the rotor hub through hole 94 when viewed in the axial direction, and protrudes axially downward. The cylindrical portion 92 is arranged on the outer edge of the disc portion 91. The inner diameter of the cylindrical portion 92 is larger than the outer diameter of the bearing sleeve 40. The inner circumferential surface of the cylindrical portion 92 faces the outer circumferential surface of the bearing sleeve 40 with a gap therebetween.

[0054] The outer edge portion 93 is an annular member. The outer edge portion 93 is provided at the lower end of the cylindrical portion 92. The outer edge portion 93 protrudes radially outward from the cylindrical portion 92 and is formed in a flange shape. A plurality of recording disks 4 are placed above the outer edge portion 93 and radially outward from the cylindrical portion 92 (see FIG. 1).

[0055] The rotor magnet 100 is an annular member having a magnetic pole structure magnetized with polarities inverted as N, S, N, S... along the circumferential direction when viewed in the axial direction. In this embodiment, the rotor magnet 100 is attached to the inner peripheral surface of an annular yoke 101 attached to the lower end of the outer edge portion 93. The rotor magnet 100 is located at approximately the same position as the stator core 60 in the axial direction, and is located between the stator core 60 and the inner peripheral surface of the circumferential groove portion 32 in the radial direction.

[0056] The yoke 101 suppresses leakage of magnetic flux from the rotor magnet 100. Alternatively, the cylindrical portion 92 or the outer edge portion 93 may be disposed between the stator core 60 and the inner peripheral surface of the circumferential groove portion 32, and the annular yoke 101 may be attached to the inner peripheral surface of the cylindrical portion 92 or the inner peripheral surface of the outer edge portion 93. In this case, the rotor magnet 100 is attached to the inner peripheral surface of the yoke 101 so as to face the stator core 60.

[0057] <Spindle motor operation> When the coil 61 is energized, a magnetic attractive force and a magnetic repulsive force are alternated between the magnetic poles of the rotor magnet 100 and the pole teeth of the stator core 60. As a result, the rotating part 20 rotates relative to the stationary part 10 with the shaft 80 as the rotation axis.

[0058] The shaft 80 rotates relative to the bearing sleeve 40. At this time, the lubricating oil is pressurized by the radial dynamic pressure generating grooves 84, generating dynamic pressure in the lubricating oil. The generated dynamic pressure supports the shaft 80 in a radially non-contact state relative to the bearing sleeve 40.

[0059] As the shaft 80 rotates, the shaft flange portion 82 also rotates. At this time, the lubricating oil is pressurized by the thrust dynamic pressure generating grooves 85, generating dynamic pressure in the lubricating oil. The generated dynamic pressure supports the shaft 80 in a non-contact state in the axial direction relative to the bearing sleeve 40 and the counter plate 55.

[0060] <Modification> The spindle motor 3 may be a combination of the modifications described below.

[0061] (1) Variation 1 As shown in FIGS. 4 and 5, the bearing sleeve 40 may have a recess 148 .

[0062] The recess 148 is a recess provided in the main body portion 41. The recess 148 is provided on the outer peripheral surface 41b of the main body portion 41, extending in the circumferential direction. The recess 148 is provided in the contact portion 70 when the bearing sleeve 40 is press-fitted into the case 50. In particular, the recess 148 is preferably provided in the lower end portion 71b of the first region 71, which is connected to the upper end portion 72a of the second region 72.

[0063] The recess 148 may be provided in the first region 71 and the second region 72. Fig. 6 shows an example in which the recess 148 is provided in the second region 72. Furthermore, although the example in which the recess 148 is provided in the main body portion 41 of the bearing sleeve 40 has been described, the recess 148 may also be provided in the case 50.

[0064] By providing the recess 148 in the contact portion 70, even if processing oil infiltrates the contact portion 70, the processing oil that has infiltrated is retained in the recess 148. Therefore, the processing oil is less likely to seep out onto the upper end surfaces of the bearing sleeve 40 and the case 50.

[0065] Furthermore, since the recess 148 is provided in the bearing sleeve 40 or the case 50, the protrusion 42 is more likely to deform. In particular, since the recess 148 is provided in the lower end 71b of the first region 71 that is connected to the upper end 72a of the second region 72 (the portion where the first region 71 and the second region 72 are connected), the protrusion 42 is more likely to deform. As a result, the force with which the protrusion 42 presses the inner circumferential surface of the upper-end recess 54 in the axial direction becomes stronger. Therefore, the gap at the joint between the protrusion 42 and the upper-end recess 54 becomes smaller.

[0066] (2) Variation 2 The protrusion 42 and the upper end recess 54 may be a protrusion 142 and an upper end recess 154 as shown in FIGS.

[0067] The protrusion 142 is a member provided on the upper end and radially outer side of the main body 41. The protrusion 142 protrudes radially outward from the outer circumferential surface of the upper end 44 of the main body 41. The protrusion 142 is provided around the entire circumferential circumference of the upper end 44.

[0068] The upper-end recess 154 is a recess provided at the upper end of the case main body 51. The upper-end recess 154 is a cylindrical space provided so as to be coaxial with the central axis of the through-hole 52 when viewed in the axial direction. The upper-end recess 154 opens upward. The diameter of the upper-end recess 154 is larger than the diameter of the through-hole 52 and is approximately the same as or smaller than the outer diameter of the protrusion 142. The inner circumferential surface of the upper-end recess 154 may be tapered, with the inner diameter increasing from bottom to top. In this case, the inner diameter of the upper end of the upper-end recess 154, where the inner diameter is largest, is approximately the same as or smaller than the outer diameter of the protrusion 142.

[0069] Next, the relationship between the bearing sleeve 40 and the case 50 will be described. The bearing sleeve 40 is press-fitted into the case body 51 from above in the axial direction so that the outer peripheral surface 41b of the body 41 faces the inner peripheral surface 51a of the case body 51. At this time, the bearing sleeve 40 is press-fitted until the lower surface of the protrusion 142 contacts the bottom surface of the upper-end recess 154. Here, because the inner diameter of the upper-end recess 154 is approximately the same as or smaller than the outer diameter of the protrusion 142, the bearing sleeve 40 is press-fitted into the case body 51 while the protrusion 142 deforms the upper-end recess 154 or while the protrusion 142 itself is deformed. For this reason, the gap at the joint between the protrusion 142 and the upper-end recess 154 is extremely small. Furthermore, because the lower surface of the protrusion 142 contacts the bottom surface of the upper-end recess 154, a force is generated that presses the lower surface of the protrusion 142 against the bottom surface of the upper-end recess 154 in the axial direction. Therefore, the gap between the lower surface of the protrusion 142 and the bottom surface of the upper end recess 154 is also very small. In this manner, the bearing sleeve 40 and the case 50 are joined together.

[0070] By press-fitting the bearing sleeve 40 having the protrusion 142 into the case 50 having the upper-end recess 154, a contact portion 70 is formed between the two components. The contact portion 70 has a first region 71 where the protrusion 142 and the bottom surface of the upper-end recess 154 are in contact in a direction intersecting the axial direction, and a second region 72 where the main body portion 41 and the case main body portion 51 are in contact in the axial direction. The first region 71 and the second region 72 are continuous at the inner end 71b of the first region 71 and the upper end 72a of the second region 72. The outer end 71a of the first region 71 is also continuous at the lower end 72b of the second region 72.

[0071] (3) Variation 3 The protruding portion 142 described in the second modification may further have an axial protruding portion 142a as shown in FIGS.

[0072] The axial protruding portion 142a is a member provided on the lower surface of the protruding portion 142. The axial protruding portion 142a protrudes in the axial direction from the lower surface of the protruding portion 142. The axial protruding portion 142a is provided around the entire circumferential circumference of the protruding portion 142. The axial length (i.e., height) of the axial protruding portion 142a is approximately the same as or longer than the axial length of the upper end recess 154 minus the axial length of the protruding portion 142.

[0073] Next, the relationship between the bearing sleeve 40 and the case 50 will be described. The bearing sleeve 40 is press-fitted from the axially upper side into the case body 51 so that the outer peripheral surface 41b of the body 41 faces the inner peripheral surface 51a of the case body 51. At this time, the bearing sleeve 40 is press-fitted until the axial protrusion 142a provided on the lower surface of the protrusion 142 comes into contact with the bottom surface of the upper-end recess 154. Here, because the lower surface of the axial protrusion 142a comes into contact with the bottom surface of the upper-end recess 154, a force is generated that causes the lower surface of the axial protrusion 142a to press against the bottom surface of the upper-end recess 154 in the axial direction. As a result, the gap between the lower surface of the axial protrusion 142a and the bottom surface of the upper-end recess 154 becomes very small. In this manner, the bearing sleeve 40 and the case 50 are joined together.

[0074] A contact portion 70 is formed between the two components by press-fitting the bearing sleeve 40, which has the protrusion 142 and the axial protrusion 142a, into the case 50, which has the upper end recess 154. The contact portion 70 has a first region 71 where the axial protrusion 142a and the upper end recess 154 are in contact in a direction intersecting the axial direction, and a second region 72 where the main body portion 41 and the case main body portion 51 are in contact in the axial direction. In this modification, the first region 71 and the second region 72 are separated from each other in the radial direction.

[0075] (4) Variation 4 Case 50 may have a shape that does not have upper end recess 54 and upper end recess 154. That is, case main body 51 is provided with through hole 52. Note that inner circumferential surface 51a formed by providing through hole 52 in case main body 51 may be parallel to the axial direction, or may have a tapered shape in which the inner diameter increases or decreases from one end to the other end in the axial direction (for example, from the upper end to the lower end).

[0076] (5) Variation 5 The shape of the protruding portion 42 of the bearing sleeve 40 press-fitted into the case 50 of the fourth modification may be, for example, such that the protruding portion 42 is provided from the upper end to the lower end of the case main body 51, or from the upper end to near the lower end. The outer diameter of the protruding portion 42 is larger than the maximum diameter of the through hole 52 (the hole diameter at the upper end of the through hole 52). It is also conceivable that the outer diameter of the outer peripheral surface of such protruding portion 42 is tapered, decreasing from top to bottom. In this case, the minimum diameter of the outer diameter of the outer peripheral surface of the protruding portion 42 (the outer diameter at the lower end) is larger than the maximum diameter of the through hole 52.

[0077] (6) Variation 6 When press-fitting the bearing sleeve 40 into the case 50, an adhesive may also be used. For example, the bearing sleeve 40 may be press-fitted into the case 50 with adhesive applied to one or both of the outer circumferential surface 41b of the bearing sleeve 40 and the inner circumferential surface 51a of the case 50. By press-fitting the bearing sleeve 40 into the case 50 in this manner, an adhesive layer is formed at the contact portion 70.

[0078] (7) Variation 7 In the above embodiment and modified examples, examples have been described in which a protrusion is provided on the bearing sleeve 40 and a recess that pairs with the protrusion is provided on the case 50. It is sufficient that the protrusion is provided on at least one of the bearing sleeve 40 and the case 50. Therefore, the protrusion may be provided on the case 50 and a recess that pairs with the protrusion may be provided on the bearing sleeve 40.

[0079] (8) Variation 8 In the above embodiment and modified examples, an example of a hard disk drive 1 including a spindle motor 3 has been described. The motor is not limited to the spindle motor 3, and the above configuration may be applied to any motor. Furthermore, the rotation drive device is not limited to the hard disk drive 1, and the above motor may be applied to any rotation drive device such as a fan, a LiDAR (Light Detection and Ranging) sensor, or a projector.

[0080] <Effects> (Aspect 1) The spindle motor 3 of this embodiment comprises a bearing sleeve 40 formed in a cylindrical shape extending in the axial direction, a case 50 formed in a cylindrical shape extending in the axial direction and arranged radially outwardly perpendicular to the axial direction so as to contact the outer peripheral surface 41b of the bearing sleeve 40, and a protrusion 42 provided on at least one of the bearing sleeve 40 and the case 50 at a contact portion 70 between the bearing sleeve 40 and the case 50, the contact portion 70 having a first region 71 intersecting the axial direction, the protrusion 42 being provided in the first region 71, and the bearing sleeve 40 being press-fitted into the case 50.

[0081] In the spindle motor 3 described above, the bearing sleeve 40 is press-fit into the case 50, and the protrusion 42 of the bearing sleeve 40 is provided in a first region 71 of the contact portion 70 between the bearing sleeve 40 and the case 50 that intersects with the axial direction, so that the protrusion 42 presses the case 50 in the axial direction. This makes the gap between the contact portion 70 between the bearing sleeve 40 and the case 50 extremely small. As a result, when the upper end surfaces of the bearing sleeve 40 and the case 50 are finish-machined using machining oil, the machining oil is less likely to seep into the gap at the contact portion 70. In other words, in the motor of the above aspect, the machining oil used during finish-machining of the sleeve and case is less likely to seep into the gap between the case and sleeve components.

[0082] Furthermore, with the spindle motor 3 in the above aspect, the processing oil used in the finish processing is less likely to infiltrate the gaps in the contact portions 70, and the processing oil that has infiltrated the gaps in the contact portions 70 is less likely to come out of the gaps. This means that the processing oil is less likely to mix with the lubricating oil in the fluid dynamic bearing filled between the bearing sleeve 40 and the shaft 80. As a result, the lubricating oil is less likely to deteriorate, and the life of the spindle motor 3 can be extended.

[0083] (Embodiment 2) In embodiment 1, the first member is the bearing sleeve 40 and the second member is the case 50.

[0084] According to the spindle motor 3 described above, the processing oil used in the finish processing of the bearing sleeve 40 and the case 50 is less likely to enter the gaps in the contact portions 70 .

[0085] (Embodiment 3) In embodiment 1 or 2, contact portion 70 is the portion where outer peripheral surface 41b contacts inner peripheral surface 51a of case 50, and in first region 71, the outer diameter of outer peripheral surface 41b and the inner diameter of inner peripheral surface 51a are tapered toward one side in the axial direction.

[0086] According to the above-described spindle motor 3, the outer diameter of the outer peripheral surface 41b and the inner diameter of the inner peripheral surface 51a are tapered so as to become smaller toward one side in the axial direction, so that the lower surface of the protruding portion 42 of the bearing sleeve 40 is pressed against the inner peripheral surface 51a of the case 50. Therefore, the gap between the contact portion 70 of the bearing sleeve 40 and the case 50 becomes very small.

[0087] (Embodiment 4) In embodiment 3, the taper angle of the outer peripheral surface 41b and the inner peripheral surface 51a is 30 degrees or more and 60 degrees or less.

[0088] According to the above-described spindle motor 3, the taper angle of the outer peripheral surface 41b and the inner peripheral surface 51a is between 30 degrees and 60 degrees, so that the lower surface of the protruding portion 42 of the bearing sleeve 40 is easily pressed against the inner peripheral surface 51a of the case 50. Therefore, the gap at the contact portion 70 between the bearing sleeve 40 and the case 50 becomes very small.

[0089] (Embodiment 5) In embodiment 3 or 4, the contact portion 70 further has a second region parallel to the axial direction, and the contact portion 70 further includes a recess 148 provided in at least one of the bearing sleeve 40 and the case 50, the lower end 71b of the first region 71 being connected to the upper end 72a of the second region 72, and the recess 148 being provided in the lower end 71b.

[0090] According to the above-described spindle motor 3, the recess 148 is provided at the lower end 71b of the first region 71 where the first region 71 and the second region 72 are connected, and therefore the protrusion 42 is easily deformed. As a result, the force with which the protrusion 42 presses the inner circumferential surface of the upper-end recess 54 in the axial direction becomes stronger, and the gap at the contact portion 70 between the bearing sleeve 40 and the case 50 becomes smaller.

[0091] (Embodiment 6) In embodiment 1 or 2, a recess 148 is further provided in at least one of the bearing sleeve 40 and the case 50 at the contact portion 70 between the bearing sleeve 40 and the case 50 .

[0092] According to the spindle motor 3 described above, since the recess 148 is provided in the contact portion 70, even if processing oil enters the contact portion 70 during finish processing, the entering processing oil remains in the recess 148. Therefore, the processing oil is less likely to seep out onto the upper end surfaces of the bearing sleeve 40 and the case 50.

[0093] (Embodiment 7) In any of Embodiments 1 to 6, the contact portion 70 has an adhesive layer.

[0094] According to the above-described spindle motor 3, the contact portion 70 has an adhesive layer, which significantly reduces the gap at the contact portion between the outer peripheral surface 41b of the bearing sleeve 40 and the inner peripheral surface 51a of the case 50. Therefore, processing oil used in the finish processing of the bearing sleeve 40 and the case 50 is less likely to infiltrate into the gap at the contact portion 70.

[0095] (Eighth Embodiment) The hard disk drive device 1 includes the spindle motor 3 according to any one of the first to seventh embodiments.

[0096] According to the above hard disk drive device 1, the lubricating oil in the fluid dynamic bearing used in the spindle motor 3 is less likely to deteriorate, and the life of the spindle motor 3 is longer. Therefore, the life of the hard disk drive device 1 is extended. [Explanation of symbols]

[0097] 1...hard disk drive device (rotary drive device), 3...spindle motor (motor), 40...bearing sleeve (first member), 41b...outer peripheral surface, 42, 142...protruding portion, 50...case (second member), 51a...inner peripheral surface, 70...contact portion, 71...first region, 71b...lower end portion (one end portion), 72...second region, 72a...upper end portion (other end portion), 142a...axial protruding portion (protruding portion), 148...recess

Claims

1. a first member formed in a cylindrical shape extending in an axial direction; a second member formed in a cylindrical shape extending in the axial direction and disposed radially outward of the first member in contact with an outer circumferential surface of the first member, the second member being orthogonal to the axial direction; a protrusion provided on at least one of the first member and the second member at a contact portion between the first member and the second member; Equipped with the contact portion has a first region intersecting the axial direction, the protrusion is provided in the first region, The first member is press-fitted into the second member. Motor.

2. The motor of claim 1 , wherein the first member is a sleeve and the second member is a case.

3. the contact portion is a portion where the outer circumferential surface and the inner circumferential surface of the second member come into contact with each other, The motor according to claim 1 , wherein in the first region, an outer diameter of the outer circumferential surface and an inner diameter of the inner circumferential surface are tapered so as to become smaller toward one side in the axial direction.

4. The motor according to claim 3 , wherein the taper angles of the outer peripheral surface and the inner peripheral surface are equal to or greater than 30 degrees and equal to or less than 60 degrees.

5. The contact portion further has a second region parallel to the axial direction, The contact portion further includes a recess provided in at least one of the first member and the second member, one end of the first region in the axial direction is connected to the other end of the second region in the axial direction, The recess is provided at the one end. The motor according to claim 3.

6. The motor according to claim 1 , further comprising a recess provided in at least one of the first member and the second member in the contact portion.

7. The motor of claim 1 , wherein the contact portion includes an adhesive layer.

8. A rotary drive device comprising the motor according to any one of claims 1 to 7.

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