WO2004081399A1 - 流体動圧軸受、モータ、および記録媒体駆動装置 - Google Patents
流体動圧軸受、モータ、および記録媒体駆動装置 Download PDFInfo
- Publication number
- WO2004081399A1 WO2004081399A1 PCT/JP2004/003193 JP2004003193W WO2004081399A1 WO 2004081399 A1 WO2004081399 A1 WO 2004081399A1 JP 2004003193 W JP2004003193 W JP 2004003193W WO 2004081399 A1 WO2004081399 A1 WO 2004081399A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- shaft
- dynamic pressure
- shaft body
- insertion hole
- liquid
- Prior art date
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/02—Parts of sliding-contact bearings
- F16C33/04—Brasses; Bushes; Linings
- F16C33/06—Sliding surface mainly made of metal
- F16C33/10—Construction relative to lubrication
- F16C33/1025—Construction relative to lubrication with liquid, e.g. oil, as lubricant
- F16C33/106—Details of distribution or circulation inside the bearings, e.g. details of the bearing surfaces to affect flow or pressure of the liquid
- F16C33/107—Grooves for generating pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C17/00—Sliding-contact bearings for exclusively rotary movement
- F16C17/02—Sliding-contact bearings for exclusively rotary movement for radial load only
- F16C17/026—Sliding-contact bearings for exclusively rotary movement for radial load only with helical grooves in the bearing surface to generate hydrodynamic pressure, e.g. herringbone grooves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C17/00—Sliding-contact bearings for exclusively rotary movement
- F16C17/10—Sliding-contact bearings for exclusively rotary movement for both radial and axial load
- F16C17/102—Sliding-contact bearings for exclusively rotary movement for both radial and axial load with grooves in the bearing surface to generate hydrodynamic pressure
- F16C17/107—Sliding-contact bearings for exclusively rotary movement for both radial and axial load with grooves in the bearing surface to generate hydrodynamic pressure with at least one surface for radial load and at least one surface for axial load
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/08—Structural association with bearings
- H02K7/085—Structural association with bearings radially supporting the rotary shaft at only one end of the rotor
Definitions
- the present invention relates to a liquid dynamic pressure bearing for rotatably supporting a shaft by a dynamic pressure of a liquid filled in a gap between the shaft supporting portion, a motor including the liquid dynamic pressure device, and a recording including the motor.
- the present invention relates to a medium drive device.
- the liquid dynamic pressure bearing 80 includes an outer peripheral surface of a disc-shaped thrust bearing member 82 of a shaft head 81, an end surface of a radial bearing cylindrical portion 83, and a sleeve 85.
- a dynamic pressure generating portion is formed that collects oil 91 in gaps R1 to R3 between the shaft body and the inner surface of the insertion hole 86 to generate thrust dynamic pressure and radial dynamic pressure.
- Oil reservoirs S1 to S4 are formed at the respective ends of the gaps R1 to R3.
- the liquid pressure of the oil 91 in the narrow gap R4 formed between the end face 83a of the opposing shaft body 81 decreases, and cavitation (bubbles) is generated. Also, when manufacturing the liquid dynamic pressure bearing 80, the oil 91 is injected after the air in the gap between the outer surface of the shaft body 81 and the inner surface of the sleeve 85 is injected. In some cases, bubbles may remain in the gap R4 located farthest from the open end 86b of the shaft body insertion hole 86 of the sleeve 85.
- the present invention has been made in view of the above-described circumstances, and has been made in consideration of the fact that bubbles existing in a gap between an end surface of a shaft and a closed end surface of a shaft support portion reach a gap where dynamic pressure is generated.
- the purpose of the present invention is to provide a liquid dynamic pressure bearing which can prevent the occurrence of the problem and maintain good bearing characteristics. Disclosure of the invention
- a liquid dynamic pressure bearing according to the present invention includes a shaft, a shaft support portion having a closed end, and having a shaft insertion hole for accommodating the shaft in rotation, the shaft and the shaft inserted. Comprising a liquid filled in a gap formed between the hole, the liquid, A dynamic pressure generating portion formed by at least one of the outer surface of the shaft body and the inner surface of the shaft body insertion hole; Alternatively, a recess is formed in any one of the center portions of the end faces of the shaft body facing the shaft body.
- the shaft supporting portion rotatably supports the shaft by the dynamic pressure generated in the dynamic pressure generating portion.
- the liquid in the gap between the closed end face of the shaft support portion and the end face of the shaft (hereinafter, referred to as the closed end face side gap) is collected in the dynamic pressure generation section, so that the closed end face side is closed.
- the hydraulic pressure in the gap between the two decreases, causing cavitation (bubbles).
- the recess by forming the recess, the amount of liquid that can be stored in the gap on the closed end face side can be increased, so that a decrease in the liquid pressure due to the generation of dynamic pressure is suppressed, and the generation of cavitation (bubbles) is suppressed. be able to. Furthermore, by forming the concave portion, the distance between the closed end face of the shaft body insertion hole and the end face of the shaft body is widened, so that the viscous resistance of the liquid generated when the shaft body rotates is reduced.
- the shaft body has a thrust shaft portion formed in a flange shape at a central portion in the axial direction, and a radial shaft portion formed in a cylindrical shape on both axial sides of the thrust shaft portion. And a supporting portion, wherein the shaft support portion forms a closed end side of the shaft insertion hole, and a small-diameter cylindrical portion for rotatably inserting the radial shaft portion; A large-diameter cylindrical portion forming an open end side for rotatably inserting the thrust shaft portion, and an upper cover for closing an open end of the shaft body insertion hole and forming a cabillary seal with the support portion
- the thrust shaft portion and the radial shaft portion respectively constitute the dynamic pressure generating portion, and the outer peripheral surface of the radial shaft portion and the small diameter opposed to the outer peripheral surface from the concave portion.
- a connection groove extending toward a gap between the cylindrical portion and the inner peripheral surface is provided.
- the liquid dynamic pressure bearing when the shaft body rotates, the gap between the outer peripheral surface of the radial shaft portion and the inner peripheral surface of the small-diameter cylindrical portion (hereinafter referred to as “the liquid force s”) and the dynamic pressure generating groove are formed. This is called the gap on the peripheral surface.)
- the liquid pressure near the peripheral edge of the gap between the closed end face of the small-diameter cylindrical portion and the end face of the shaft (hereinafter, referred to as the closed end face-side gap) decreases, and the clearance at this peripheral edge decreases. Bitation (bubbles) occurs.
- the fluid pressure at the center of the gap on the closed end face side is lower than the fluid pressure at the gap on the peripheral face side. As a result, it moves toward the center of the gap on the closed end face side, and is housed in the recess.
- a plurality of bubbles are accommodated in the recess along the connection groove, they are connected to each other and grow into a large-sized bubble.
- the shaft body is formed by an inner surface of the shaft body insertion hole facing a shaft body corner formed by an outer circumferential surface of the radial shaft portion and an axial surface of the thrust shaft portion adjacent to the outer circumferential surface.
- a step is formed at the corner of the insertion hole to widen the gap between the shaft and the shaft support.
- the liquid dynamic pressure bearing when the shaft body rotates, the liquid force s and the dynamic pressure generating groove cause the clearance on the peripheral surface side of the radial shaft portion and the surface of the thrust shaft portion. And the small-diameter cylindrical portion is gathered in the gap between the end face on the open end side. At this time, since the liquid pressure in the gap between the corner of the shaft body and the corner of the insertion hole decreases, a cavity (bubble) is generated in this gap. Even if a force such as a liquid flow from the gap to the dynamic pressure generating section acts on the bubble, the movement of the bubble is hindered by the step formed at the corner of the insertion hole. Therefore, the bubbles can be prevented from reaching the dynamic pressure generating portion.
- the liquid dynamic pressure bearing is characterized in that the support portion, the radial shaft portion and the thrust shaft portion are integrally formed.
- the rigidity of the shaft body can be improved.
- the diameter of the thrust shaft part is increased, so that the axial dynamic pressure generated in the thrust shaft part can be easily increased. Vibration can be easily prevented.
- the motor according to the present invention is characterized by including the liquid dynamic pressure bearing, and a driving unit for rotating the shaft with respect to the shaft support.
- the shaft can be rotated stably.
- a recording medium driving device includes the motor, and a hub that rotatably supports a thin recording medium is attached to the shaft.
- FIG. 1 is a sectional view showing a recording medium driving device according to a first embodiment of the present invention.
- FIG. 1 is a sectional view showing a recording medium driving device according to a first embodiment of the present invention.
- FIG. 2 is an enlarged cross-sectional view illustrating a liquid dynamic bearing in the recording medium driving device of FIG.
- FIG. 3 shows an essential part of the liquid dynamic pressure bearing of FIG. 2, and (a) is an enlarged sectional view showing a concave portion and a connecting groove formed in a closed end face of a shaft body insertion hole, and (b) () Is a cross-sectional view taken along line A_A of (a).
- FIG. 4 is a schematic diagram showing the behavior of bubbles generated in a gap between the end face of the shaft and the closed end face of the shaft insertion hole in the liquid dynamic pressure bearing of FIG.
- FIGS. 5A and 5B show a liquid dynamic bearing of a recording medium drive according to a second embodiment of the present invention.
- FIG. 5A is an enlarged sectional view
- FIG. It is an expanded sectional view showing the state where it did.
- FIG. 6 is an enlarged cross-sectional view showing a concave portion and a connecting groove formed in a closed end face of a shaft insertion hole in a liquid dynamic pressure bearing of a recording medium driving device according to another embodiment.
- FIG. 7 is an enlarged cross-sectional view showing a main part of a liquid dynamic pressure bearing of a recording medium driving device according to another embodiment, showing a concave portion and a connecting groove formed on a closed end face of a shaft body insertion hole
- (b) is a sectional view taken along the line BB of (a).
- FIG. 8 is an enlarged cross-sectional view illustrating a liquid dynamic pressure bearing of a recording medium driving device according to another embodiment.
- FIG. 9 is a sectional view showing an example of a conventional liquid dynamic pressure bearing. BEST MODE FOR CARRYING OUT THE INVENTION
- the liquid dynamic pressure bearing according to this embodiment is applied to a recording medium drive for rotating a disk-type recording medium such as a magnetic recording medium formed in a thin disk shape.
- the recording medium driving device 60 includes a liquid dynamic pressure shaft. It comprises a receiver 1, a hub 31 for fixing a disk-type recording medium 55, and a driving means 40 for rotating the hub 31.
- the liquid dynamic pressure bearing 1 has a shaft 3 formed in a cylindrical shape having a substantially cross-shaped cross section, and a shaft insertion hole 5 a having a substantially cross-shaped cross section for rotatably housing the shaft 3.
- a sleeve (shaft support portion) 5 having the following, and an oil (liquid) 7 filled in a gap between the shaft insertion hole 5 a and the shaft 3.
- the shaft body 3 includes a thrust shaft portion 9 formed in a flange shape at a central portion in the axial direction, and a substantially cylindrical support portion 11 and a radial shaft projecting from both sides in the direction of the center axis A1. Part 13 is provided.
- the shaft 3 is formed by turning, and the thrust shaft 9, the support 11 and the radial shaft 13 are formed integrally. .
- a plurality of dynamic pressure generating grooves 15 having a shape called a helix bone are formed on the outer peripheral surface (outer surface) 13 a of the radial shaft portion 13.
- a plurality of spiral dynamic pressure generating grooves are formed on the front surface (outer surface) 9a and the back surface (outer surface) 9b of the thrust shaft portion 9.
- These dynamic pressure generating grooves collect oil 7 and generate dynamic pressure when the shaft body 3 is rotated around the central axis A 1, and the shaft 5 is rotatably supported by the sleep 5. That is, the dynamic pressure of the oil 7 generated in the dynamic pressure generating groove 15 of the radial shaft portion 13 acts as a radial bearing of the shaft body 3 and is generated in the dynamic pressure generating groove of the thrust shaft portion 9.
- the dynamic pressure of the oil 7 serves as a bearing in the direction of the central axis A 1 of the shaft 3.
- the oil 7 and the dynamic pressure generating groove form a dynamic pressure generating part 26.
- a recess is formed at the radially inner peripheral edge of the thrust shaft 9 from the front surface 9a and the back surface 9b in the direction of the center axis A1.
- a concave portion is formed that sinks inward in the radial direction from the outer peripheral surface 13a.
- the sleeve 5 is a bottomed cylindrical sleeve body 1 having a shaft body insertion hole 5a.
- the sleeve body 17 is provided with a small-diameter cylindrical portion 21 and a large-diameter cylindrical portion 23, and the small-diameter cylindrical portion 21 and the large-diameter cylindrical portion 23 are integrally formed by turning. It is.
- the small-diameter cylindrical portion 21 has a hole 22 that forms the closed end side of the shaft insertion hole 5a, and the radial shaft portion 13 can be inserted into the hole 22. .
- the oil 7 is collected in the gap R 3 between the inner peripheral surface 2 2 b of the hole 22 and the outer peripheral surface 13 a of the radial shaft portion 13, and the dynamic pressure is reduced. appear. '
- the closed end surface (inner surface) of the hole 22 facing the end surface 1 3 b of the radial shaft portion 13 2 b has a concave portion 2 5 sinking in the direction of the center axis A 1 in the center portion. Is formed. Further, a plurality of connection grooves 27 extending radially outward from the peripheral edge of the recess 25 to the peripheral edge of the closed end face 22a are formed in the closed end face 22a. The depth and width of the connecting groove 27 are smaller and smaller than the depth of the concave portion.
- the large-diameter cylindrical portion 23 has a through hole 24 that forms the open end side of the shaft body insertion hole 5a, and the through hole 24 includes a thrust shaft portion. 9 can be inserted.
- the concave portion 25 When the concave portion 25 is formed at the center of the closed end face 22a, machining of the shaft body insertion hole 5a of the sleeve 5 becomes easy. In other words, when forming the shaft body ⁇ 'insertion hole 5a, while the sleep 5 is rotated around the center axis A1, the closed end face 22a is formed by face milling, but the closed end face 22a is formed. in Since the cutting speed in the central part is low, it is difficult to finish the closed end face 22a with high accuracy. On the other hand, when the concave portion 25 is formed in advance, the closed end face 22 a may be formed only on the peripheral edge of the oil portion 25, so that the closed end face 22 a can be easily finished with high accuracy. It becomes.
- the upper plate 19 is formed in a substantially disk shape, and has a through hole 20 for inserting the support portion 11 in the direction of the center axis A1.
- the through hole 20 constitutes a shaft body insertion hole 5a together with the hole 22 of the small diameter cylindrical portion 21 and the through hole 24 of the large diameter cylindrical portion 23.
- a capillar seal is provided between the upper plate 19 and the support portion 11, and the capillar seal allows the gap between the shaft body 3 and the shaft body insertion hole 5a to be removed. To prevent leakage.
- the hub 31 has a bottom wall portion 33 formed in a substantially disk shape, and a substantially cylindrical cylindrical wall portion protruding from the periphery of the bottom wall portion 33 in the direction of the central axis A1. It consists of 3 and 5.
- a through-hole 33 a is formed in the center of the bottom wall 33, and the through-hole 33 a is formed in the support portion 11 of the shaft 3 outside the shaft insertion hole 5 a. This is for fitting the end 11a protruding into the hole.
- the hub 31 is arranged so as to cover the liquid dynamic bearing 1.
- the driving means 40 includes an annular permanent magnet 42, and a core 44 and a coil 46 arranged at positions facing the outer peripheral surface 42 a side of the permanent magnet 42.
- the permanent magnet 42 is attached to the outer peripheral surface 35a of the cylindrical wall 35 of the hub 31.
- the core 44 is fixed to an inner peripheral surface 51 a of a stator 51 formed in a shallow cylindrical shape. 'Here, the stator 51 is fixed integrally with the sleep 5. That is, a hole 51 c is formed at the center of the bottom wall 51 b of the stator 51, and the sleeve 5 is connected to the sleeve 5 by fitting the closed end side of the sleeve 5 into the hole 51 c.
- the stator 51 is fixed to each other.
- the shaft body 3 and the hub 31 rotate with respect to the sleeve 5 and the stator 51 by applying an alternating magnetic field generated in the core 44 and the coil 46 to the permanent magnet 42. It has become.
- the liquid dynamic pressure bearing 1 and the driving means 40 constitute a motor 45.
- a step 33 b for supporting the disk-type recording medium 55 is formed on the periphery of the bottom wall 33 of the knob 31. By fitting a central hole 55a formed in the center of the disk-type recording medium 55 into this step portion 33b, the disk-type recording medium 55 is centered together with the shaft 3 and the hub 31. It can rotate around axis A1.
- the hub 31 having the stepped portion 33b and the motor 45 constitute a recording medium driving device 60.
- the sleeve 5 rotatably supports the shaft body 3 by the dynamic pressure generated in the dynamic pressure generating groove.
- the oil 7 is collected in the gap R 3 where the dynamic pressure generating part 26 is located, so that the hydraulic pressure of the oil 7 around the gap R 3 is reduced, as shown in FIG.
- the gap R 4 between the closed end face 22 a of the small-diameter cylindrical section 21 and the end face 13 b of the radial shaft section 13, and cavitation (bubbles) 7 1, 7 2 are generated near the periphery of the gap R 4. I do.
- the liquid dynamic pressure bearing 1 since the air bubbles 7 1 and 7 2 generated in the gap R 4. and in the vicinity of the periphery thereof can be prevented from reaching the dynamic pressure generating section 26, The shaft 3 can be prevented from swaying, and the bearing characteristics of the liquid dynamic bearing 1 can be prevented from deteriorating.
- the space at the center of the gap R 4 is expanded, so that the oil at the center of the gap R 4 is similar to the oil reservoirs S 1 and S 2. Cuts and generation of bubbles can be suppressed, and the viscous resistance of the oil 7 generated when the shaft body 3 rotates is reduced, so that the shaft body 3 can be rotated efficiently with small energy.
- the rigidity of the shaft body 3 can be improved, and the reliability of the liquid dynamic bearing 1 can be improved.
- the dynamic pressure generated in the thrust shaft 11 can be easily increased by increasing the diameter of the thrust shaft 11 and the shaft 3 vibrates in the direction of the center axis A1. Can be easily prevented You.
- the shaft 3 can be rotated stably, so that when recording is written on the disk-type recording medium 55, It is possible to prevent a problem when reading a record from the recording medium 55.
- FIG. 5 shows a second embodiment according to the present invention.
- the embodiment shown in this figure has the same basic configuration as the fluid dynamic bearing 1 shown in FIGS.
- the shape of the small diameter cylindrical portion 21 of the sleeve 5 is different.
- the small-diameter cylindrical portion 21 in FIG. 5 will be described, and the same portions as those in FIG. 1 to FIG.
- a step portion 28 a is formed in a peripheral portion (a corner portion of an insertion hole) on an open end side of a hole 22 formed in the small-diameter cylindrical portion 21.
- the stepped portion 28 a is formed on the back surface 9 b located on the radially inner peripheral portion of the thrust shaft portion 9 and the center axis A 1 end of the radial shaft portion 13 located on the thrust shaft portion 9 side.
- a roll reservoir S2 is formed. Therefore, the oil reservoir S 2 is formed to be wider than the gaps R 2 and R 3 where the dynamic pressure generating part 26 is located.
- the oil reservoir S 2 is formed to be larger than the gaps R 2 and R 3 where the dynamic pressure generating portion 26 is located, the bubbles 73 generated in the oil reservoir S 2 are separated from the dynamic pressure generating portion 26. It can grow larger than the gaps R 2 and R 3 with gaps.
- the steps 73a and the recesses 28b, 28c are formed, so that the bubbles 73 in the oil reservoir S2 generate dynamic pressure. Since it can be prevented from reaching the part 26, the shaft body 3 can be prevented from swaying and the bearing characteristics of the liquid dynamic bearing 1 can be prevented from deteriorating.
- the step portion 28a and the concave portions 28b, 28c are formed in order to form the reservoir S2.
- the present invention is not limited to this. It is only necessary that one of the step portion 28a and the concave portions 28b and 28c be formed. Therefore, for example, only the step portion 28a may be formed.
- connection groove 27 is formed to have a shape extending radially outward.
- the present invention is not limited to this, and at least the connection groove 27 may be formed from the peripheral edge of the recess 25. What is necessary is just to form in the shape which reaches the peripheral part of the closed end face 22a. Therefore, as shown in FIG. 6, for example, the connection groove 27 may be formed in a spiral shape extending from the periphery of the concave portion 25 to the periphery of the closed end face 22a.
- the direction in which the connecting groove 27 formed spirally from the peripheral edge of the concave portion 25 is preferably opposite to the rotation direction D of the shaft 3.
- connection groove 27 is made to reach the peripheral edge of the closed end face 22a.
- the present invention is not limited to this, as long as it reaches at least the gap R3. Therefore, the connecting groove 27 may be formed from the peripheral portion of the concave portion 25 to just before the peripheral portion of the closed end face 22a.
- the connecting groove 27 is formed on the closed end face 22a together with the concave part 25.
- the present invention is not limited to this.
- a radial shaft portion facing the closed end face 22a 1 in the case 3 also good c this configuration as formed on the end face 1 3 b of, as the bubble 71 generated in the vicinity of the peripheral edge portion of the gap R 4 can accommodate easily the recess 2 5, connecting grooves 2 7
- the concave portion 25 is formed at the center of the closed end face 22a, but is not limited to this, and is formed at the center of the end face 13b of the radial shaft portion 13 facing the closed end face 22a. You may do it.
- a concave portion 25 may be formed at both the center of the closed end face 22a and the end face 13b.
- the processing of the end surface 13 b of the radial shaft portion 13 becomes easy.
- the end face 13b is formed with high precision because the end face 13b is formed by face milling while rotating the sleeve 5 around the central axis A1. It will be difficult.
- the concave portion 25 is formed in advance, the end surface 13b may be formed only on the peripheral portion of the concave portion 25, and thus the end surface 13b can be easily finished with high accuracy.
- the dynamic pressure generating groove forming the dynamic pressure generating part 26 in the axial direction is Although it is described that the shaft 9 is formed on the front surface 9a and the back surface 9b, the present invention is not limited to this. 21 may be formed on the end face in the axial direction. Also, the dynamic pressure generating groove 15 constituting the radial dynamic pressure generating portion 26 is formed on the outer peripheral surface 13 a of the radial shaft portion 13, but the present invention is not limited to this. It may be formed on the inner peripheral surface 22 b of the small-diameter cylindrical portion 21 facing the outer peripheral surface 13 a of 13.
- the shaft body 3 is constituted by the thrust shaft portion 9, the substantially cylindrical support portion 11 protruding to both sides in the direction of the center axis A 1, and the radial shaft portion 13.
- the present invention is not limited to this.
- the radial shaft portion 13 may be configured to protrude from the surface 9a of the thrust shaft portion 9 toward the open end of the sleeve 5. Good.
- the dynamic pressure generating section 26 is formed at the peripheral portion except for the above. For this reason, when the shaft body 3 rotates with respect to the sleeve 5, the oil 7 is collected at the periphery of the gap R4, and cavitation (bubbles) is generated at the center of the gap R4.
- the bubble is subjected to dynamic pressure. Can be prevented from reaching the generating part 26.
- the effect of preventing the movement to the dynamic pressure generating part 26 is not only caused by the bubbles generated as the hydraulic pressure decreases, but also in the production of the liquid dynamic bearing 1. It is also effective for bubbles remaining in the gap R4 when the oil 7 is injected.
- the core 44 and the coil 46 are arranged to face the outer peripheral surface 42a of the annular permanent magnet 42.
- the present invention is not limited to this.
- the driving means 40 for rotating the shaft 3 and the hub 31 by the permanent magnet 42, the core 44 and the coil 46 may be used. Therefore, the core 44 and the coil 46 may be arranged at positions facing the inner peripheral surface side of the permanent magnet 42. In this configuration, the permanent magnet 42 may be fixed to the inner peripheral surface of the hub 31, and the core 44 and the coil 46 may be fixed to the outer peripheral surface of the sleeve 5 facing this inner peripheral surface. Ray.
- the present invention by forming a concave portion and a connecting groove, or by forming a step portion, a gap near the closed end face side, a bubble near the peripheral edge thereof, a corner portion of the insertion hole, or the like. Since it is possible to prevent the air bubbles in the gap located at the position from reaching the dynamic pressure generating portion, it is possible to prevent the shaft from swaying and prevent the bearing characteristics of the liquid dynamic pressure bearing from deteriorating. In addition, since the viscous resistance of the liquid generated when the shaft rotates is reduced by forming the recess, the shaft can be efficiently rotated with small energy.
- the rigidity of the shaft body is improved by integrally forming the shaft body, the reliability of the liquid dynamic pressure bearing can be improved, and the diameter of the thrust shaft portion can be increased to increase the shaft diameter. It is possible to easily prevent the body from vibrating in the axial direction.
- liquid dynamic pressure bearing when the liquid dynamic pressure bearing is provided in the motor, stable rotation of the shaft body can be realized with a constant driving force, so that the driving force of the driving means can be easily controlled and the energy required for the driving force can be improved. Labor saving can be easily achieved.
- the shaft when the liquid dynamic pressure bearing is provided in the recording medium driving device, the shaft can be rotated stably, so that when recording is performed on the recording medium or when recording is read from the recording medium. Can be prevented.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Power Engineering (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
- Sliding-Contact Bearings (AREA)
- Motor Or Generator Frames (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2003-070223 | 2003-03-14 | ||
JP2003070223A JP2006177375A (ja) | 2003-03-14 | 2003-03-14 | 液体動圧軸受、モータ、および記録媒体駆動装置 |
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WO2004081399A1 true WO2004081399A1 (ja) | 2004-09-23 |
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PCT/JP2004/003193 WO2004081399A1 (ja) | 2003-03-14 | 2004-03-11 | 流体動圧軸受、モータ、および記録媒体駆動装置 |
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WO (1) | WO2004081399A1 (ja) |
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WO2018106611A1 (en) * | 2016-12-08 | 2018-06-14 | Cr Flight | High current and rpm-capable slip ring assembly |
WO2019147587A1 (en) | 2018-01-23 | 2019-08-01 | Cr Flight, Llc | Counter-rotating electric motor system for high efficiency operation of a hybrid or electric vehicle |
WO2019147588A1 (en) | 2018-01-23 | 2019-08-01 | Cr Flight, Llc | Hybrid vehicle counter-rotating motor adapted driveline and retro-fit system |
Citations (5)
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JPH10339320A (ja) * | 1997-06-09 | 1998-12-22 | Sankyo Seiki Mfg Co Ltd | 動圧軸受装置 |
JPH11187611A (ja) * | 1997-12-18 | 1999-07-09 | Seiko Instruments Inc | スピンドルモータ、及びスピンドルモータを回転体の駆動源とする回転体装置 |
JP2001140862A (ja) * | 1999-11-16 | 2001-05-22 | Seiko Instruments Inc | 流体動圧軸受及びスピンドルモータ |
JP2001248635A (ja) * | 2000-03-03 | 2001-09-14 | Matsushita Electric Ind Co Ltd | 動圧流体軸受装置 |
JP2001254727A (ja) * | 2000-03-10 | 2001-09-21 | Koyo Seiko Co Ltd | スラスト動圧軸受 |
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2003
- 2003-03-14 JP JP2003070223A patent/JP2006177375A/ja not_active Withdrawn
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2004
- 2004-03-11 WO PCT/JP2004/003193 patent/WO2004081399A1/ja active Application Filing
Patent Citations (5)
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JPH10339320A (ja) * | 1997-06-09 | 1998-12-22 | Sankyo Seiki Mfg Co Ltd | 動圧軸受装置 |
JPH11187611A (ja) * | 1997-12-18 | 1999-07-09 | Seiko Instruments Inc | スピンドルモータ、及びスピンドルモータを回転体の駆動源とする回転体装置 |
JP2001140862A (ja) * | 1999-11-16 | 2001-05-22 | Seiko Instruments Inc | 流体動圧軸受及びスピンドルモータ |
JP2001248635A (ja) * | 2000-03-03 | 2001-09-14 | Matsushita Electric Ind Co Ltd | 動圧流体軸受装置 |
JP2001254727A (ja) * | 2000-03-10 | 2001-09-21 | Koyo Seiko Co Ltd | スラスト動圧軸受 |
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JP2006177375A (ja) | 2006-07-06 |
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