JP3429797B2 - Spindle motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor. 2. Description of the Related Art Conventionally, in a spindle motor in which a flange on which a stator is externally fitted is attached to a shaft, one end of the flange has an outer diameter substantially the same as the outer diameter of the stator. A thin flexible circuit board is fixed to a surface of the outer flange on the side of the stator, and a land is formed on a surface of the circuit board facing the stator. The coil lead wire was soldered to the land at the narrow space between the two. However, in the conventional spindle motor as described above, since the soldering work is performed in a narrow space between the stator and the flexible circuit board, there is a problem that the workability is deteriorated. And soldering failure. In addition, there is a possibility that the raised soldered portion may come into contact with the coil wire of the stator. Although the outer flange of the flange has a large diameter (similar to the outer diameter of the stator), it is cut from a thick cylindrical body while leaving the outer flange. When the outer flange portion is large in diameter, the volume of the portion to be removed by cutting becomes large. This causes a problem that the material is wasted and the material cost is increased. Therefore, the present invention solves such a problem, and can easily and reliably connect the lead wire of the stator coil to the land portion of the flexible circuit board. It is an object of the present invention to provide a spindle motor that can be used. SUMMARY OF THE INVENTION A spindle motor according to the present invention includes a flange having a cylindrical portion externally fitted near one end of a shaft and a low outer flange formed at one end of the cylindrical portion. A stator externally fitted to the cylindrical portion of the flange;
A stator corresponding surface portion facing one end surface of the stator with a small clearance, and an inner peripheral edge of the stator corresponding surface portion;
Is formed integrally in a straight line at the cylindrical portion of the flange.
A reinforcing plate comprising a cylindrical portion to be fitted over and further fixed to the flange as an engagement with the low outer flange portion of the flange,
A flexible circuit board having an annular surface portion fixed to the outer surface of the stator corresponding surface portion of the reinforcing plate and a band-shaped lead portion extending radially outward from the annular surface portion;
A land portion is formed on the outer surface of the annular surface portion of the flexible circuit board, and an end of a coil lead wire of the stator is connected to the land portion beyond the outer peripheral edge of the reinforcing plate. [0007] The coil lead wire of the stator is drawn out, and the outer peripheral edge of the reinforcing plate and the outer peripheral edge of the annular surface portion of the flexible circuit board are passed over. The soldering work of the end of the lead wire can be easily performed on the outer surface side where there is no obstacle. Further, since the soldered portion is on the outer surface side of the annular surface portion of the flexible circuit board, it does not contact the coil wire of the stator. Furthermore, it does not come into contact with the rotating rotor magnet, hub, or the like, and is not damaged. When the low outer flange portion of the flange is formed by cutting, the volume of the portion to be removed by cutting becomes small, and waste of material can be reduced. The present invention will be described below in detail with reference to the drawings showing embodiments. FIG. 1 is a sectional view of an embodiment of a spindle motor according to the present invention. In FIG. 1, reference numeral 1 denotes a shaft, and a shaft hole of the shaft 1 is opened at one end and the other end, respectively. 2a and 2b, and are fixed to a frame (not shown) with screws or the like. Reference numeral 10 denotes a hub on which a magnetic disk or the like is mounted.
A bush 11 also serving as a yoke is fitted inside the hub 10. The bush 11 is pivotally supported on the shaft 1 via bearings 12,12. As a result, the hub 10 is connected to the shaft 1
Is rotatably held around the axis of the shaft. On the inner peripheral portion of the hub 10 corresponding to the other end of the shaft 1, a magnetic fluid sealing device 13 for preventing grease or the like from flowing out is provided on the bearings 12, 12. Bearings 12, 12
A labyrinth cap 14 for preventing grease or the like from flowing out is mounted in the cylinder of the bush 11 on the side opposite to the side where the magnetic fluid sealing device 13 is attached. An annular rotor magnet 15 is fixed in the cylinder at one end of the bush 11. In this spindle motor, the flange 3 composed of the cylindrical portion 6 fixed to the outside of the shaft 1 near one end and the low outer flange portion 7 formed at one end of the cylindrical portion 6 is formed. The stator 4 is fixed to the cylindrical portion 6 of the flange 3 so as to be fitted externally. As shown in FIG. 2, the stator 4 comprises a stator core 8 and a stator coil 9 wound therearound.
15 is opposed with a minute gap. An annular reinforcing plate 5 which is viewed from the axial direction is fixed to the lower outer flange 7 of the flange 3 so as to be engaged with the lower outer flange 7. More specifically, the reinforcing plate 5 is opposed to one end surface of the stator 4 with a small clearance C, and has an annular stator corresponding surface portion 16 whose inner peripheral portion is in close contact with the lower outer flange portion 7 of the flange 3. And a cylindrical portion 17 which is formed integrally with the inner peripheral edge of the stator corresponding surface portion 16 as an orthogonal shape and which is press-fit into the cylindrical portion 6 of the flange 3 so as to be fitted externally. The outer diameter of the stator corresponding surface portion 16 of the reinforcing plate 5 is set to be substantially the same as or slightly larger than the outer diameter of the stator 4. An insulating paper (not shown) is attached to a surface of the reinforcing plate 5 on a side facing the stator 4. A flexible circuit board 18 is adhered to the outer surface of the stator corresponding surface portion 16 of the reinforcing plate 5. (Returning to FIG. 1) More specifically, the flexible circuit board 18 has an annular surface portion 19 fixed to the outer surface of the stator corresponding surface portion 16, and a belt-like shape extending radially outward from the annular surface portion 19. A lead 22 is provided, and a connector 22 is fixed to the tip of the strip-shaped lead 20. In the reinforcing plate 5, a step 21 is formed in a portion corresponding to a continuous portion between the annular surface portion 19 of the flexible circuit board 18 and the strip-shaped lead portion 20 by press working. The step portion 21 separates the base of the strip-shaped lead portion 20 from the bush 11 so as not to hit the rotating bush 11. As shown in FIG. 2, a land 23 is formed on the outer surface of the annular surface portion 19 of the flexible circuit board 18, and the coil lead wire end 24 of the stator 4 is connected to the land portion.
23, it connects beyond the outer peripheral edge of the reinforcing plate 5. As shown in FIGS. 2 and 3, land portions 23 are provided at a plurality of locations on the outer surface of the annular surface portion 19 of the flexible circuit board 18.
... are formed. That is, the flexible circuit board 18
Are composed of two flexible films and a wiring pattern 27 made of copper foil interposed between the two flexible films.
The base end of the connector 22 is a land 23 and the tip is the connector 22.
Connected to. Further, each land portion 23 of the annular surface portion 19
.. Are formed in the vicinity of the outer periphery, and a notch 26 is formed in a portion of the reinforcing plate 5 corresponding to the slit 25 of the annular surface portion 19 of the flexible circuit board 18. Is formed. Then, as shown in FIG.
Then, the coil lead wire end 24 is drawn out to the outer surface side through the coil lead wire end 24 to the notch 26, and the coil lead wire end 24 is electrically connected to the land 23 by soldering. With this configuration, the coil lead wire end 24 can be soldered to the land 23 on the outer surface side of the annular surface 19 of the flexible circuit board 18,
Soldering work can be facilitated. In addition, even when the clearance C between the reinforcing plate 5 and the stator 4 is set small, it is possible to prevent a defect such as a short circuit. In this spindle motor, the stator 4 is externally fitted to the cylindrical portion 6 of the flange 3 before assembly is completed.
Land portion of flexible circuit board 18 fixed to reinforcing plate 5
The coil lead wire end 24 can be connected to 23 as described above. As described above, there is an advantage that the production can be made extremely easy by being made into a subunit. As shown in FIG. 5, the flange 3 is formed by cutting and removing a portion A indicated by an imaginary line from a cylindrical material. The height dimension H is low (8 of the outer flange of the conventional flange).
(Approximately 1/3 to 1/3), whereby the cut portion A is reduced. Therefore, material waste can be reduced, and material costs can be reduced. This has the advantage that it can be manufactured at low cost. In the examples shown in FIGS. 3 and 4, the slit portion 25 has a keyhole shape in which a cut is made linearly in the radial direction and a circular hole is formed at the tip. Any shape can be used as long as the end portion 11 can be inserted and held. For example, a circular hole may be omitted and only a straight cut may be used. Next, as shown in FIG. 6, the tip of the strip-shaped lead 20 of the flexible circuit board 18 is
Are formed at the left and right ends of the base of the turning piece 30 so that the turning piece 30 can be easily turned.
31, 31 are formed. The folded piece 30 is formed with lands 28 for connector connection, and each of the lands 28 is provided with a hole 29 for inserting a connector pin therethrough. When the folded piece 30 is folded as shown by the arrow B in the drawing and overlapped with a portion adjacent to the folded piece 30 in the strip-shaped lead portion 20, the folded portion in the adjacent portion is folded. Holes 32 for inserting connector pins are also provided through portions of the piece 30 corresponding to the holes 29. Thus, as shown in FIG.
30 is folded back and adhered to a portion adjacent to the folding piece 30 in the strip-shaped lead portion 20 and adhered, and from the surface (lower surface) opposite to the surface (upper surface) on the side where the lands 28 are exposed. The above hole
Insert the connector pins 33 ... into the holes 32 ... and the holes 29 ...
22 is attached, and the distal ends of the connector pins 33 are projected toward the lands 28. Then, this tip is connected to the lands 28 by soldering. The reason why the strip-shaped lead portion 20 is constructed in this manner is that the connector 22 is attached to the lower surface side of the flexible circuit board 18 as shown in FIG. That is, in the state where the folding piece 30 is not folded (the state shown in FIG. 6), the lands 28 are exposed on the lower surface side. The connector 22 faces and the land 28
Cannot be soldered to the connector pins 33. However, as shown in FIG. 7, if the folding piece 30 is folded, the lands 28 are exposed on the upper surface side. 28 ... side and connector pin 33
Can be easily soldered to the lands 28. In addition, the strength of the portion to which the connector 22 is attached is increased, and effective reinforcement can be performed. FIG. 8 shows a modification of the folding piece 30. As shown in FIG. In this case, the folding piece 30 is formed on one of the left and right sides of the strip-shaped lead part 20 and is configured to fold the folding piece 30 around the one side as shown by an arrow C. Conversely, when the connector 22 is mounted on the upper surface of the strip-shaped lead portion 20, it is not necessary to turn the base end as described above, and the holes 32 can be omitted. The present invention can be freely modified in design other than the above-described embodiment without departing from the scope of the invention. For example, the outer diameter of the annular surface 19 of the flexible circuit board 18 and the outer diameter of the stator corresponding surface 16 of the reinforcing plate 5 are reduced, and the slits 25 and the notches 26 are omitted. The coil lead wire end 24 may be formed so as to extend beyond the outer peripheral edges of the annular surface 19 and the stator corresponding surface 16. The present invention is configured as described above.
The following effects are obtained. In the spindle motor in which the flange 3 to which the stator 4 is fixed is fitted to the shaft 1, the coil lead wire end 24 of the stator 4 is easily fitted to the land 23 of the flexible circuit board 18. And it can connect reliably. This facilitates manufacture and prevents occurrence of defective products. Further, the waste of the material of the flange 3 can be reduced, the material cost can be saved, and the whole can be made inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged sectional front view showing one embodiment of the present invention. FIG. 2 is an enlarged sectional view of a main part. FIG. 3 is a bottom view of a main part. FIG. 4 is an enlarged perspective view of a main part. FIG. 5 is a cross-sectional view illustrating a main part. FIG. 6 is an enlarged perspective view illustrating a main part. FIG. 7 is an enlarged perspective view illustrating a main part. FIG. 8 is an enlarged perspective view showing a modification of the flexible circuit board. [Description of Signs] 1 Shaft 3 Flange 4 Stator 5 Reinforcement plate 6 Cylindrical portion 7 Low outer flange portion 16 Stator corresponding surface portion 18 Flexible circuit board 19 Annular surface portion 20 Band-shaped lead portion 23 Land portion 24 Coil lead wire end C Clearance

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 3/50 H02K 3/04 H02K 5/22

Claims (1)

(1) A flange (3) comprising a cylindrical portion (6) externally fitted near one end of the shaft (1) and a low outer flange portion (7) formed at one end of the cylindrical portion (6). a stator 4 which is fitted onto the cylindrical portion 6 of the flange 3, the stator corresponding surface portion 16 及 opposed with a slight clearance C between one end face of the stator 4
And formed integrally in a straight line on the inner peripheral edge of the stator corresponding surface portion 16.
Cylindrical portion fitted to the cylindrical portion 6 of the flange 3
A reinforcing plate 5 is fixed to the flange 3 becomes a further locking shape in the Teisototsuba portion 7 of the flange 3 to 17, an annular surface portion which is secured to the outer surface of the stator corresponding surface portion 16 of the reinforcing plate 5 19 and a flexible circuit board 18 having a band-shaped lead portion 20 extending radially outward from the annular surface portion 19. A land portion 23 is provided on the outer surface of the annular surface portion 19 of the flexible circuit board 18. A spindle motor formed and connected with the coil lead wire ends 24 of the stator 4 to the lands 23 beyond the outer peripheral edge of the reinforcing plate 5.