JP2006052782A - Sliding bearing unit built in rfid tag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding bearing unit built in a RFID tag which can acquire information regarding a quality control, etc. from an exterior without removing a built-in apparatus by mounting the gap for the RFID for recording information, etc., regarding quality. <P>SOLUTION: A bearing member 8 is fixed to the inner peripheral surface of a housing 7 including a cylindrical side and a bottom. A shaft member 2 is inserted into the inner peripheral surface of the bearing member 8. The shaft member 2 is rotatably supported without contact by a dynamic pressure operation generated when the shaft member 2 and the bearing member 8 relatively rotate. The RFID tag 20 is mounted in the housing 7. Any of the information regarding respective parts of a unit for constituting the hydraulic bearing unit 1 and a lot number, a bearing gap, delivery inspection information, etc. of a completed product is recorded in the RFID tag 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sliding bearing unit having a built-in RFID tag, and more particularly to a sliding bearing unit having a built-in RFID (Radio Frequency Identification) tag for reading and writing data without contact.

  The slide bearing includes a dynamic pressure bearing having a groove in a bearing portion and a bearing having no groove. Such slide bearings are used in information equipment, for example, magnetic disk drive devices such as HDD and FDD, optical disk drive devices such as CD-ROM, CD-R / RW, and DVD-ROM / RAM, and magneto-optical disks such as MD and MO. It is used for spindle motors such as drive devices, polygon scanner motors of laser beam printers (LBP), or small motors such as electric devices such as axial fans.

A hydrodynamic bearing as an example of such a sliding bearing is, for example, as described in Japanese Patent Application Laid-Open No. 2002-61641, a fluid (oil) is filled in a gap between a shaft and a bearing, and is rotated. In addition, the rotation of the shaft is supported by utilizing the pressure (dynamic pressure) generated in the fluid. This mechanism not only has high impact resistance compared to ball bearing type bearings, but also minimizes shaft runout, so it has high rotational accuracy and can be used in the above-mentioned information equipment to increase capacity and speed. Can be realized. In addition, since the shaft rotates without contacting the bearing, the noise is high, and the bearing portion can be further downsized.
JP 2002-61641 A

  The hydrodynamic bearing described in Patent Document 1 is incorporated in a spindle motor or the like as described above. When a malfunction occurs, the hydrodynamic bearing history is confirmed, and the hydrodynamic bearing manufactured in the same lot is tracked. You may need to investigate. Since the hydrodynamic bearing is built into the spindle motor, it takes time unnecessarily to remove the hydrodynamic bearing, and there is a problem that the countermeasure cannot be taken immediately and the user is inconvenienced. .

  On the other hand, in recent years, traceability requirements for quality control have increased, and in the quality control of machine element products such as dynamic pressure bearings, material information, production information, inspection information, shipping information, inspection information, etc. can be immediately identified. It is hoped that.

  Therefore, an object of the present invention is to incorporate an RFID tag that can be used to obtain information on quality control from the outside without being removed from the built-in device by attaching an RFID tag that records information on quality and the like. It is to provide a plain bearing unit.

  The present invention comprises a housing including a substantially cylindrical side portion and a bottom portion, a bearing member fixed to the inner peripheral surface of the housing, and a shaft member inserted through the inner peripheral surface of the bearing member. For slide bearing units that are supported in the radial direction by rotation relative to the bearing member, at least one of the history information such as the lot number, bearing clearance, and shipping inspection information of each component that constitutes the slide bearing unit and the finished product The RFID tag for recording is attached to at least one of the components constituting the slide bearing unit.

  As a result, for example, a reader / writer or the like can read out information related to the sliding bearing unit without removing the sliding bearing unit from, for example, a motor in which the sliding bearing unit is incorporated. Further, if information after the plain bearing unit is incorporated in the motor is written in the RFID tag, the traceability from the motor to be incorporated and the apparatus in which the motor is incorporated becomes easy.

  Preferably, a recess is formed on the surface of the housing, and an RFID tag is attached to the recess and then sealed with resin. By mounting the RFID tag on the surface of the housing, information can be read from the RFID tag in a non-contact manner even when the plain bearing unit is incorporated in a motor or the like.

  Preferably, the housing is formed by resin or metal injection molding. Injection molding can be performed with a metal such as MIM.

  Preferably, the housing includes a gate portion, and a recess is formed by additionally processing the gate portion, and the RFID tag is provided.

  According to the present invention, by mounting an RFID tag on the housing, information relating to the sliding bearing unit is read out by, for example, a reader / writer without removing the sliding bearing unit from, for example, a motor in which the sliding bearing unit is incorporated. It becomes possible. Thereby, the acquisition of the information regarding the sliding bearing unit can be accelerated. Moreover, since it does not take time to remove the sliding bearing unit and consumes time unnecessarily, it is possible to take measures immediately and to eliminate the possibility of inconvenience the user.

  FIG. 1 is a schematic cross-sectional view showing the structure of a spindle motor having a hydrodynamic bearing device as an example of a slide bearing unit incorporating an RFID tag according to an embodiment of the present invention. The spindle motor shown in FIG. 1 is used in a disk drive device such as an HDD. The hydrodynamic bearing device 1 rotatably supports a shaft member 2 in a non-contact manner, and a disk hub 3 is mounted on the shaft member 2.

  The disk hub 3 is rotationally driven by a spindle motor including a stator 4 and a rotor 5, and the rotor 5 is disposed on the inner peripheral surface of the disk hub 3. The hydrodynamic bearing device 1 is attached to the inner peripheral surface of the casing 6, and the stator 4 is disposed on the outer peripheral surface of the casing 6 so as to have a predetermined gap in the radial direction with respect to the rotor 5.

  The disk hub 3 holds one or more disks D such as magnetic disks. When the stator 4 is energized, the rotor 5 is rotated by the exciting force between the stator 4 and the rotor 5, whereby the disk hub 3 and the shaft member 2 are rotated together.

  2 is a cross-sectional view of the dynamic pressure bearing device shown in FIG. 1, and FIG. 3 is an example of a dynamic pressure groove pattern of the dynamic pressure bearing portion included in the dynamic pressure bearing device shown in FIG.

  In FIG. 2, the hydrodynamic bearing device 1 includes a shaft member 2, a housing 7, and a cylindrical bearing member 8 fixed to the inner peripheral surface of the housing 7. The housing 7 is formed of a resin including a substantially cylindrical side portion and a bottom portion. The shaft member 2 includes a shaft portion 2a and a flange portion 2b provided integrally with or separately from the shaft portion 2a.

  The bearing member 8 is made of, for example, a porous material, in particular, a sintered metal, and an oil-impregnated bearing is obtained by impregnating the internal pores with lubricating oil or lubricating grease. Although not shown, a dynamic pressure groove is formed in a region of the inner peripheral surface of the bearing member 8 that serves as a radial bearing surface. When the shaft member 2 rotates, a dynamic pressure action is generated in the radial bearing gap, and the shaft portion 2a of the shaft member 2 is non-contacted freely in the radial direction by the lubricating oil or lubricating oil film formed in the radial bearing gap. Supported by The dynamic pressure groove may be formed on the outer peripheral surface of the shaft portion 2 a of the shaft member 2.

  A dynamic pressure groove 2c as shown in FIG. 3 is formed under the bearing member 8 and in a region serving as a thrust bearing surface on the inner surface of the housing 7. When the shaft member 2 rotates, a dynamic pressure action is generated in the thrust bearing gap between the upper surface of the flange portion 2 b and the lower end surface of the bearing member 8 and between the lower end surface of the flange portion 2 b and the inner surface of the housing 7. It is supported in a non-contact manner so as to be rotatable in the thrust direction. The thrust bearing surface may be provided on the upper end surface of the housing.

  After the opening at the top of the bearing member 8 is sealed with a seal washer 9 made of metal or resin, lubricating oil or lubricating grease is injected, and air check and oil amount confirmation are performed so that there is no residual air inside the shaft member 8. Is called.

  In addition, the shape of the dynamic pressure groove formed on the radial bearing surface and the thrust bearing surface can be arbitrarily selected, and a herringbone type, a spiral type, a step type, a multi-arc type or the like is selected, or Any combination of these may be used.

  A recess 10 is formed on the back surface of the housing 7, and an RFID tag 20 is attached to the recess 10 and sealed with an adhesive 11. The adhesive 11 can be simply processed by using an ultraviolet curing type. The RFID tag 20 records information about history such as lot numbers, bearing gaps, and shipping inspection information of each part of the unit constituting the hydrodynamic bearing device 1 and a finished product.

  The housing 7 can be formed by resin or metal injection molding. Injection molding can also be performed with metal by MIM (powder injection molding) or the like.

  FIG. 4 is a cross-sectional view showing another example of the pivot type dynamic pressure bearing device, and FIG. 5 shows a dynamic groove pattern of the dynamic pressure bearing portion included in the dynamic pressure bearing device shown in FIG. It is an example.

  The hydrodynamic bearing device 1 shown in FIG. 2 described above is provided with the flange portion 2b, whereas the hydrodynamic bearing device 1a shown in FIG. A bearing member 18 that supports the shaft portion 12 a of the shaft member 12 and a seal washer 19 are provided. As shown in FIG. 5, a dynamic pressure groove 18 a is formed on the inner peripheral surface of the bearing member 18. In addition, although not shown, a dynamic pressure groove is formed on the lower end surface of the shaft member 12 and the bottom portion of the housing 17 facing the shaft member 12. A recess 10 is formed on the back surface of the housing 17, and an RFID tag 20 is attached to the recess 10 and sealed with an adhesive 11.

  When the shaft member 12 rotates, a dynamic pressure action is generated in the gap between the bottom of the housing 17 and the lower end surface of the bearing member 8 and between the shaft member 12 and the inner peripheral surface of the bearing member 18, and the radial direction And it is supported in a non-contact manner so as to be rotatable in the thrust direction. Also in this example, the RFID tag 20 records information relating to the history such as each part of the unit constituting the hydrodynamic bearing device 1a and the lot number of the finished product, bearing clearance, and shipping inspection information.

  FIG. 6 is a circuit diagram showing the configuration of the RFID tag. As shown in FIG. 6, the RFID tag 20 includes a planar antenna 21, a transmission / reception circuit 23, a CPU 24, a power supply circuit 25, and a memory 26 disposed on a substrate 22. The memory 26 is composed of a non-volatile memory that keeps stored information even when the power is turned off, and information can be rewritten.

  By bringing the reader / writer 28 close to the planar antenna 21 of the RFID tag 20, a high frequency signal is supplied from the reader / writer 28, and the power supply circuit 25 of the RFID tag 20 converts the high frequency signal into electric power to transmit / receive the circuit. 23, the CPU 24, and the memory 26 to activate them so that necessary information can be written into the memory 26 and the written information can be read out.

  In this embodiment, the memory 26 is written with information on history such as lot numbers, bearing gaps, shipping inspection information, etc., of each part of the unit constituting the hydrodynamic bearing device 1 and the finished product. Moreover, you may make it write the date information etc. which inspected the hydrodynamic bearing apparatus 1. FIG.

  As described above, according to this embodiment, by attaching the RFID tag 20 to the housings 7 and 17, the hydrodynamic bearing devices 1 and 1a are removed from, for example, a motor in which the hydrodynamic bearing devices 1 and 1a are incorporated. For example, the reader / writer 28 can read information related to the hydrodynamic bearing devices 1 and 1a. Thereby, the acquisition of the information regarding the hydrodynamic bearing devices 1 and 1a can be accelerated. Moreover, since it does not take time to remove the hydrodynamic bearing devices 1 and 1a and consumes time unnecessarily, it is possible to take measures immediately and eliminate the possibility of causing trouble for the user. .

  In the above description, the RFID tag 20 is mounted on the back surfaces of the housings 7 and 17. However, the present invention is not limited to this, and the RFID tag 20 is mounted on the surfaces of the seal washers 9 and 19. Also good.

  If a heat-resistant RFID tag 20 is used, lubricating oil or lubricating grease is injected into the bearing members 8 and 18 by embedding the RFID tag 20 in the housing after injection molding of the housings 7 and 17. At this time, oil or the like does not adhere to the RFID tag 20.

  Furthermore, in the above-described embodiment, the housings 7 and 17 have side portions and bottom portions, and the upper portions of the bearing members 8 and 18 are sealed with the seal washers 9 and 19, but the lower portions have gates that are open. Using a housing, a bowl-shaped portion surrounding the periphery of the shaft members 2 and 12 is formed as the bearing members 8 and 18, the shaft member and the bearing member are inserted from the gate at the lower part of the housing, and the gate of the housing is formed with a resin washer. You may make it seal. In that case, a recess may be formed on the back surface of the resin washer, and the RFID tag 20 may be attached thereto and sealed with resin.

  The present invention can also be applied to a hydrodynamic bearing device having a structure in which the housings 7 and 17 and the bearing members 8 and 18 are integrated.

  Furthermore, the present invention can also be applied to a slide bearing that does not have a dynamic pressure groove.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The slide bearing unit incorporating the RFID tag of the present invention can be used as a bearing for a spindle motor or the like used in information equipment.

It is a schematic sectional drawing which shows the structure of the spindle motor which has a hydrodynamic bearing apparatus of an example of the slide bearing unit which incorporated the tag for RFID in one Embodiment of this invention. It is sectional drawing of the dynamic pressure bearing apparatus shown in FIG. It is an example of the dynamic pressure groove pattern of the dynamic pressure bearing part contained in the dynamic pressure bearing apparatus shown in FIG. It is sectional drawing which shows the pivot type fluid dynamic bearing apparatus of the other example of a fluid dynamic bearing apparatus. It is an example of the dynamic pressure groove pattern of the dynamic pressure bearing part contained in the dynamic pressure bearing device shown in FIG. It is a circuit diagram which shows the structure of the tag for RFID.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Dynamic pressure bearing apparatus, 2, 12 Shaft member, 2a, 12a Shaft part, 2b Flange part, 2c, 18a Dynamic pressure groove, 7, 17 Housing, 8, 18 Bearing member, 9, 19 Seal washer, 10 Recessed part, 11 Adhesive, 20 RFID tag, 21 planar antenna, 22 substrate, 23 transceiver circuit, 24 CPU, 25 power supply circuit, 26 memory, 28 reader / writer.

Claims (4)

The housing includes a substantially cylindrical side portion and a bottom portion, a bearing member fixed to the inner peripheral surface of the housing, and a shaft member inserted through the inner peripheral surface of the bearing member, the shaft member and the In the sliding bearing unit supported in the radial direction by relative rotation with the bearing member,
RFID tags for recording at least one of the parts constituting the slide bearing unit and history information such as the lot number of the finished product, bearing clearance, and shipment inspection information, and at least the parts constituting the slide bearing unit. A plain bearing unit with a built-in RFID tag, characterized by being attached to either.   2. The slide bearing incorporating the RFID tag according to claim 1, wherein a concave portion is formed on a surface of the housing, and the RFID tag is attached to the concave portion and then sealed with a resin. unit.   3. The plain bearing unit incorporating the RFID tag according to claim 1, wherein the housing is formed by injection molding of resin or metal.   4. The sliding bearing unit with a built-in RFID tag according to claim 3, wherein the housing includes a gate portion, the recess is formed by additionally processing the gate portion, and the RFID tag is provided.

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