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WO1998019072A1 - Roulement et moteur - Google Patents

Roulement et moteur Download PDF

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Publication number
WO1998019072A1
WO1998019072A1 PCT/JP1997/003903 JP9703903W WO9819072A1 WO 1998019072 A1 WO1998019072 A1 WO 1998019072A1 JP 9703903 W JP9703903 W JP 9703903W WO 9819072 A1 WO9819072 A1 WO 9819072A1
Authority
WO
WIPO (PCT)
Prior art keywords
bearing
rotating shaft
rotor
lubricating oil
peripheral surface
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP1997/003903
Other languages
English (en)
Japanese (ja)
Inventor
Yasuhiro Taguchi
Eiichi Miyashita
Tadashi Komatsu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Epson Corp
Original Assignee
Seiko Epson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seiko Epson Corp filed Critical Seiko Epson Corp
Publication of WO1998019072A1 publication Critical patent/WO1998019072A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • F16C17/00—Sliding-contact bearings for exclusively rotary movement
    • F16C17/02—Sliding-contact bearings for exclusively rotary movement for radial load only
    • 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
    • F16C23/00—Bearings for exclusively rotary movement adjustable for aligning or positioning
    • F16C23/02—Sliding-contact bearings
    • F16C23/04—Sliding-contact bearings self-adjusting
    • F16C23/041—Sliding-contact bearings self-adjusting with edge relief
    • 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
    • F16C33/103—Construction relative to lubrication with liquid, e.g. oil, as lubricant retained in or near the bearing
    • F16C33/104—Construction relative to lubrication with liquid, e.g. oil, as lubricant retained in or near the bearing in a porous body, e.g. oil impregnated sintered sleeve
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K5/00—Casings; Enclosures; Supports
    • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
    • H02K5/167—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using sliding-contact or spherical cap bearings
    • 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
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/30—Angles, e.g. inclinations
    • 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
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
    • 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
    • F16C2380/00—Electrical apparatus
    • F16C2380/26—Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators
    • F16C2380/27—Motor coupled with a gear, e.g. worm gears

Definitions

  • the present invention relates to a bearing and a motor having the same, and more particularly to driving a big lens of a storage medium such as a DVD, and a lens for focusing and focusing in an optical device such as a camera or a video camera. Stepping mo used — relating to the evening. Background art
  • a small stepping motor with a lead screw installed on its rotating shaft is used for driving a lens for forcing singles.
  • characteristics such as low power consumption, long life, low noise, and low vibration, excellent responsiveness, and self-starting characteristics are required for reasons related to the application. You.
  • FIG. 8 is a cross-sectional view showing a conventional stepping motor bearing
  • FIG. 9 is an enlarged view of the bearing shown in FIG.
  • the right side in FIGS. 8 and 9 is referred to as “leading end”, and the left side is referred to as “proximal end”.
  • the conventional bearing 100 shown in these figures is a sliding bearing (sintered oil-impregnated bearing) which is formed of a sintered body and is used by impregnating (occluding) lubricating oil.
  • the bearing 100 has a rotating shaft support 101 that supports the rotating shaft 200 of the stepping motor.
  • an enlarged portion 102 On the distal end side of the rotating shaft support 101, an enlarged portion 102 whose inner diameter is larger than the inner diameter L14 of the rotating shaft support 101 is formed. 2 prevents the rotation shaft 200 from contacting the inner surface of the enlarged diameter portion 102.
  • the inner diameter L15 of the enlarged diameter portion 102 has a constant size from its distal end to its proximal end.
  • the lubricating oil impregnated in the bearing 100 is sucked out of the rotating shaft support 101 by a pump action based on the rotation of the rotating shaft 200. Also, the lubricating oil oozes out of the rotating shaft support 101 due to a decrease in viscosity of the lubricating oil due to frictional heat and thermal expansion. As a result, an oil film is formed on the bearing sliding surface (the joint surface between the bearing 100 and the rotating shaft 200), that is, the inner surface of the rotating shaft support 101, and the oil film forms the rotating shaft supporting portion. The friction between 101 and the rotating shaft 200 is reduced, and the rotating shaft 200 rotates smoothly.
  • the enlarged diameter portion 102 of the conventional bearing 100 is generally formed in this shape due to the ease of machining of the mold during the production of the bearing.
  • the lubricant flows excessively from the tip of the rotating shaft support portion 101 toward the enlarged diameter portion 102, thereby consuming lubricating oil and shortening the life of the bearing 100. .
  • the friction may cause the bearing 100 and the rotating shaft 200 to be scraped and clogged with wear powder, and the motor may not rotate.
  • the temperature of the lubricating oil rises due to frictional heat, and the lubricating oil is oxidized (deteriorated). As a result, the friction increases, the bearing 100 and the rotating shaft 200 are scraped, the wear powder is clogged, and the motor may not rotate.
  • the inner diameter L14 of the rotating shaft supporting portion 101 and the rotating shaft supporting portion 101 is increased, that is, the joint area between the bearing 100 and the rotating shaft 200 is increased, thereby reducing the surface pressure of the rotating shaft supporting portion 101 and the lubricating oil. It has been proposed to reduce the amount of runoff.
  • An object of the present invention is to provide a bearing and a bearing capable of suppressing the consumption of lubricating oil without increasing the frictional resistance of the rotating shaft, thereby improving the durability of the bearing.
  • An object of the present invention is to provide a motor having a bearing like a cat. Disclosure of the invention
  • a sliding bearing composed of a sintered body and impregnated with lubricating oil
  • a shaft supporting portion that supports the rotating shaft and has the same and smallest inner diameter along the axial direction, and a bearing that is formed integrally with the shaft supporting portion at one end of the shaft supporting portion and that fits and fixes a bearing Having a fixed part,
  • bearing fixing portion has a tapered portion whose inner diameter gradually increases in a direction away from the shaft supporting portion.
  • a sliding bearing composed of a sintered body and used by being impregnated with a lubricating oil
  • a shaft supporting portion that supports the rotating shaft and has the same and smallest inner diameter along the axial direction, and a bearing that is formed integrally with the shaft supporting portion at one end of the shaft supporting portion and that fits and fixes a bearing Having a fixed part,
  • the bearing fixing portion has a taper portion having an inner diameter gradually increasing in a direction away from the shaft support portion and having a taper angle such that an oil reservoir of the lubricating oil can be formed at an end on the shaft support portion side.
  • a bearing comprising:
  • a motor comprising a stator and a rotor, wherein the rotating shaft of the rotor is supported by the bearing according to (1) or (2).
  • a stator having at least one set of an inner yoke, an outer yoke, and a coil installed therebetween, a rotor rotatably inserted inside the stator, and a rotation axis of the rotor
  • the bearing according to the above (1) or (2), wherein the plurality of magnetic poles formed on the inner yoke and the plurality of magnetic poles formed on the outer yoke comprise: It is characterized by being alternately arranged along the outer peripheral surface.
  • a stator having at least one set of an inner yoke, an outer yoke, and a coil installed therebetween, a rotor rotatably inserted inside the stator, and a rotating shaft of the rotor.
  • a motor wherein a plurality of magnetic poles formed on the inner yoke and a plurality of magnetic poles formed on the outer yoke are alternately arranged along the outer peripheral surface of the rotor.
  • FIG. 1 is a plan view showing an embodiment in which the motor of the present invention is applied to a steering motor.
  • Fig. 2 is a sectional view taken along the line II-II in Fig. 1.
  • FIG. 3 is a sectional view showing the bearing of the motor shown in FIG.
  • Fig. 4 is an enlarged view of the bearing shown in Fig. 3.
  • FIG. 5 is a diagram schematically showing the bearing and the rotating shaft when the motor is driven in the present invention.
  • FIG. 6 is a sectional view showing another embodiment of the bearing of the present invention.
  • Fig. 7 is a diagram showing a timing chart showing the driving pattern of the steering motor in the endurance acceleration test.
  • FIG. 8 is a cross-sectional view showing a bearing of a conventional steering motor.
  • FIG. 9 is an enlarged view of the bearing shown in FIG.
  • FIG. 1 is a plan view showing an embodiment in which the motor of the present invention is applied to a stepping motor
  • FIG. 2 is a sectional view taken along the line II-II in FIG. 1
  • FIG. 3 is a bearing of the motor shown in FIG.
  • FIG. 4 is a cross-sectional view showing a bearing according to an embodiment of the present invention.
  • FIG. 4 is an enlarged view of the bearing shown in FIG.
  • the right side in FIGS. 1 and 2 is referred to as “proximal end”
  • the left side is referred to as “distal end”
  • the right side in FIGS. 3 and 4 is referred to as “distal end”
  • the left side is referred to as “proximal end j”.
  • the stepping motor 1 of this embodiment is a PM type stepping motor, which mainly includes a stator 2 and a rotation inside the stator 2.
  • Rotor 6 inserted as much as possible, bottom plate (cover) 7 fixed to the base end of stator 2, mounting plate 8 fixed to the tip of stator 2, bearings 9a, 9b, mounting It comprises a holder 10 fixed to the plate 8 and a lead screw 14 installed on the rotating shaft 61 of the rotor 6.
  • the bearing 9 a is a bearing of the present invention, that is, a sliding bearing (sintered oil-impregnated bearing) which is formed of a sintered body and is used by impregnating (occluding) lubricating oil. a will be described later in detail.
  • the stator 2 is prepared by preparing two sets of unit bodies each including a set of an inner yoke 3, an outer yoke 4, and a coil 5 installed therebetween, and these are combined with the bases 31 of the inner yokes 3. Are fixed so as to be joined. Since both units have almost the same structure, one (base end) unit will be representatively described below.
  • the outer yoke 4 is a bottomed cylindrical member made of a soft magnetic material, and has a bottom 41, a cylindrical outer peripheral portion 42 erected from the bottom 41, and a central portion of the bottom 41. And a plurality of magnetic poles 44 standing upright in the same direction from the edge of the opening 43 formed in the same direction.
  • Notches 4 5 are provided in the outer peripheral portion 42 at positions facing each other through the openings 43. And 4 6 are formed.
  • a notch 45 has a terminal portion 53 formed on a bobbin 51 to be described later inserted therethrough and protrudes outward, and a notch 46 has a positioning protrusion 5 4 formed on the pobin 51. Are fitted, whereby the bobbin 51 is positioned with respect to the outer yoke 4.
  • the number of the magnetic poles 44 is five, and each magnetic pole 44 is arranged at an equal distance from the rotation center (axis 60) of the rotor 6, that is, at equal angular intervals on a concentric circle. ing. Also, the width of each magnetic pole 44 gradually decreases in a direction away from the bottom 41.
  • a magnetic pole 34 of the inner yoke 3 described later is inserted between the adjacent magnetic poles 44 without contact.
  • the magnetic poles 34 and 44 face in opposite directions.
  • the inner yoke 3 is a member made of a soft magnetic material, and is erected from a disk-shaped (annular plate-shaped) base 31 and an edge of an opening 33 formed in the center of the base 31. And a plurality of magnetic poles 34.
  • the outer diameter of the base portion 31 is substantially the same as the outer diameter of the outer yoke 4 (more specifically, the outer diameter near the end 4 21 of the outer peripheral portion 42).
  • Notches 35 and 36 are formed on the outer periphery of the base 31 at positions facing each other via the opening 33.
  • the notch 35 has a terminal portion 53 formed on the pobin 51 passed therethrough and protrudes outward, and the notch 36 has a positioning projection 54 formed on the pobin 51 fitted therein.
  • the pobin 51 is positioned with respect to the inner yoke 3.
  • the number of the magnetic poles 34 is equal to the number of the magnetic poles 44, and each magnetic pole 34 is equidistant from the axis 60, that is, on the concentric circle, similarly to the magnetic pole 44. Are arranged at equal angular intervals. The width of each magnetic pole 34 gradually decreases in the direction away from the base 31.
  • the coil 5 is inserted into an annular space formed between the outer peripheral portion 42 and the magnetic poles 34, 44.
  • the coil 5 is obtained by applying a winding 52 to a bobbin 51 made of an insulating material such as a synthetic resin.
  • the terminal portion 53 formed on the bobbin 51 is formed by burying a pair of terminals 531 and 532 in the constituent material (synthetic resin) of the pobin 51 without contacting each other. Then, both ends of the winding 52 are electrically connected to terminals 531 and 532 of the terminal section 53 respectively.
  • the unit body as described above is fixed by, for example, welding so that the base portions 31, 31 of the inner yokes 3, 3 are joined to each other. It is preferable that the abutting surfaces 39 of the bases 31 and 31 'are joined as closely as possible, that is, in close contact. In this case, both units have a positional relationship such that the magnetic poles 34, 44 of one unit and the magnetic poles 34, 44 of the other unit are shifted by a half pole in the circumferential direction. It is fixed. With such a configuration, the number of steps in the stepping mode 1 is 20 steps in total. Note that the driving circuit of the stepping mode may further perform microstep driving.
  • the rotor 6 includes a rotating shaft 61 and a cylindrical permanent magnet 62 installed on the outer periphery of the rotating shaft 61.
  • the rotating shaft 61 and the permanent magnet 62 are formed by pressing the rotating shaft 61 into the bore (shaft hole) of the permanent magnet 62, or by inserting the rotating shaft 61 into the bore of the permanent magnet 62. They are inserted (fitted) and fixed by gluing them together or by swaging.
  • the permanent magnet 62 is multipolarly magnetized (10 poles) in the radial direction. Also permanent A groove 63 is formed along the outer periphery at a substantially central portion in the longitudinal direction of the magnet 62, that is, near the base 31 of the inner yoke 3, so that the outer diameter of the permanent magnet 62 is smaller than that of other places. You. With such a configuration, the self-starting current can be improved, and the effect of improving the characteristics of the stepping motor becomes more remarkable.
  • the permanent magnet 62 a magnet having excellent magnetic properties is used.
  • a rare earth magnet containing a rare earth element and a transition metal as a basic component, or a rare earth element, a transition metal and a polon are used as a basic component.
  • Rare earth magnets are preferably used.
  • the form (kind) of the permanent magnet 62 may be any type such as a bonded magnet or a sintered magnet.
  • the magnetic poles 3 4 and 4 4 face each other on the outer peripheral surface of the permanent magnet 6 2 except for the groove 63. I do.
  • between the outer peripheral surface of the permanent magnet 62 and each of the magnetic poles 34, 44 is preferably about 0.05 to 0.25, more preferably 0.10 to 0.20.
  • a gap (gap) 15 of the size of a marauder is formed.
  • a bottom plate 7 is fixed to the base end of the stator 2 via a lead thrust spring 71 so as to shield the inner cavity of the stator 2.
  • the lead thrust spring 71 has a plate panel 72 at the center of a thin plate-shaped member, and the rotating shaft 61 is urged (preloaded) by the plate panel 72 in the distal direction.
  • a mounting plate 8 is fixed to the tip of the stator 2, and a holder 10 is fixed to the tip of the mounting plate 8 at the support portion 11.
  • the fixing between the stator 2 and the mounting plate 8 is preferably performed by welding such as plasma welding. Further, the fixing between the support portion 11 of the holder 10 and the mounting plate 8 is preferably performed by welding such as plasma welding or by screwing.
  • the holder 10 is a plate-shaped member, and has support portions 11 and 12 formed on the base end side and the front end side thereof, respectively, formed by being bent at right angles.
  • Circular openings 111 and 81 are formed in the support part 11 and the mounting plate 8, respectively, and the bearing 9a is press-fitted in the circular opening 111.
  • a circular opening 122 is formed in the support part 122, and a bearing 9b is press-fitted into the circular opening 122.
  • the holder 10 has a mounting hole 13 for mounting the holder 10 at a predetermined position.
  • the support portion 11 constitutes a support member that supports the stator 2 and into which the bearing 9a is fitted.
  • the rotating shaft 61 is extended to the vicinity of the support portion 12 in the distal direction, and is rotatably supported by the bearings 9a and 9b. In this case, a portion in the middle of the rotating shaft 61 is supported by the bearing 9a, and the tip of the rotating shaft 61 is supported by the bearing 9b.
  • the bearing 9b is a sliding bearing made of a synthetic resin, but is not limited to this.
  • a lead screw 14 is provided at a position between the bearings 9a and 9b of the rotating shaft 61.
  • a moving body (not shown) having an engagement portion that engages with the screw of the lead screw 14 is moved in the longitudinal direction of the rotating shaft 61. It moves a distance according to the amount of rotation of screw 14.
  • the movement of the moving body can be used for driving a lens for focusing and zooming of an optical system in various optical devices such as a camera, a video camera, and a copy machine.
  • the inner yoke 3 and the outer yoke 4 may be made of a soft magnetic material such as pure iron, or a metal material such as a zinc plated steel plate or an Fe—Cr alloy.
  • the bearing 9a shown in FIGS. 3 and 4 is a sliding bearing (sintered oil-impregnated bearing) which is made of a sintered body and is used by impregnating (occluding) lubricating oil.
  • the bearing 9 a has an inner peripheral surface 9 1 1 supporting the rotating shaft 61. And a bearing fixing portion 92 for fitting the bearing 9a into the circular opening 111 of the supporting portion 11 and fixing the same.
  • the diameter of the inner peripheral surface 911 is almost the same along the axial direction, that is, it is constant from the distal end to the proximal end of the inner peripheral surface 911, and is the smallest in the inner diameter of the bearing 9a. It has become.
  • the axial length L3 of the inner peripheral surface 911 is about 0.5 to 1 mm.
  • the clearance (clearance) between the inner peripheral surface 911 and the outer peripheral surface of the rotating shaft 61 is set in proportion to the dimension of L 3.
  • the bearing fixing portion 92 is formed integrally with the shaft support portion 91 on the distal end side of the shaft support portion 91.
  • the bearing fixing portion 92 has a tapered portion 93 in which a tapered surface 931 is formed on the inner peripheral side.
  • the inner diameter of the tapered portion 93 gradually increases in a direction away from the shaft support portion 91, that is, toward the distal end.
  • the tapered surface 931 is formed continuously from the tip of the inner peripheral surface 911 of the shaft support portion 91.
  • the inner diameter of the base end of the tapered portion 93 matches the inner diameter of the tip of the inner peripheral surface 911.
  • the gap between the tapered portion 93 and the rotating shaft 61 at the base end of the tapered portion 93 becomes small, and the motor drive is performed.
  • the lubricating oil that has flowed out of the tip of the inner peripheral surface 9 11 to the taper portion 9 3 due to its surface tension collects in a small gap between the tapered portion 9 3 and the rotating shaft 6 1.
  • the oil is retained by the oil reservoir on the inner peripheral surface 911 side by capillary action, and is then again permeated into the inner peripheral surface 911.
  • sufficient oil is constantly supplied to the inner peripheral surface 911, smooth rotation is ensured by low friction, and the durability of the bearing 9a is also improved.
  • the taper angle 0 of the tapered portion 93 is preferably about 0.5 to 30 °.
  • the taper angle S exceeds 30 °, the above-mentioned lubricating oil holding ability at the base end of the tapered portion 93 decreases, and if the taper angle S is less than 0.5 °, the positioning accuracy is measured.
  • the accuracy is low, for example, when press-fitting the bearing 9a, the taper portion 93 is distorted, the rotating shaft 61 comes into contact with the taper portion 93, and the bearing 9a and the rotating shaft 61 are displaced. As a result, the load caused by the friction increases, which degrades the responsiveness and self-starting characteristics of the stepping motor 1.
  • the ratio L between the average inner diameter of the taper portion 93 (the average inner diameter of the bearing fixing portion 92) L8 and the outer diameter of the bearing fixing portion 92 (the outer diameter of the end of the bearing 9a) L6 8 / L 6 is preferably about 0.4 to 0.6.
  • a step 96 is formed on the outer peripheral portion of the base end of the bearing fixing portion 92.
  • the outer diameter L6 on the distal end side of the bearing 9a is set smaller than the outer diameter L5 on the proximal end side.
  • the step 96 can be used as an index indicating the axial direction of the bearing 9a, and when the bearing 9a is pressed into the circular opening 111, the bearing can be used.
  • the direction of 9a can be easily determined, and the bearing 9a can be reliably installed in an appropriate direction.
  • the composition of the sintered body (hereinafter, simply referred to as “sintered body”) constituting the bearing 9 a as described above is not particularly limited, and may be appropriately determined according to the purpose and application.
  • the bearing 9a can be made of, for example, a sintered body obtained by sintering copper-based or iron-based metal powder. It is preferable that the sintered body contains a solid lubricant. Examples of the solid lubricant include the following 1 to 4.
  • low melting point metals such as Sn, Pb, Cd and In, oxides of heavy metals (PbO etc.), metal sulfides, metal phosphorus Oxide film, etc.
  • one or more of the solid lubricants can be used in combination.
  • the content of M o S 2 in the sintered body is preferably about 3 to 7 wt%.
  • a plurality of pores are formed in the sintered body for impregnating (occluding) lubricating oil. These holes communicate with each other so that the lubricating oil can circulate.
  • the porosity (effective porosity) of the sintered body is preferably about 15 to 25 vol%.
  • the porosity of the sintered body is almost equal to the oil content when the sintered body is impregnated with lubricating oil.
  • the porosity of the sintered body exceeds the above range, the strength decreases when the thickness of the bearing 9a is small, and if the porosity is less than the above range, the oil content is small, so the inner peripheral surface 9 When the surface pressure of 11 is high, the durability of the bearing 9a decreases.
  • the size of the holes in the inner peripheral surface 911 and the size of the holes in the taper portion 93 are almost the same. It is preferable that they coincide.
  • the lubricating oil can easily flow out from the inner peripheral surface 9 1 1 to the tapered portion 9 3. If the average diameter of the holes of the inner peripheral surface 9 11 and the taper portion 9 3 is almost the same, the lubricating oil will be subjected to hydraulic pressure fluctuation due to rotation and sliding of the rotating shaft 61. Since the circulation is performed around 9 11, the consumption of the lubricating oil can be further suppressed.
  • the size of the inner peripheral surface 911 and the size of the hole in the tapered portion 93 can be made substantially the same by performing sizing (recompression) on almost the entirety of the production. Also, the size of the holes can be freely set by appropriately setting the sizing conditions such as the pressure.
  • the lubricating oil to be impregnated into the sintered body is not particularly limited, and may be appropriately determined according to the purpose, application, performance, and the like.
  • examples of the lubricating oil include paraffinic and naphthenic mineral oils, esters, polyolefins, polyol esters, alkyl-substituted diphenyl ethers, polyphenyl ethers, fluorine Oils, synthetic oils such as silicone oils and the like can be used, but among them, it is preferable to use synthetic oils from the viewpoint of a wide operating temperature range and a long life.
  • the working temperature range of the oil used as the lubricating oil is preferably about ⁇ 50 to 150 ° C.
  • the viscosity of the oil used as the lubricating oil is preferably about 10 to 200 cst (40 ° C.), particularly preferably about 32 to 100 cst (40 ° C.).
  • [1] Prepare a mixed powder or alloy powder having a predetermined metal composition and an additive such as a solid lubricant, and, if necessary, a molding aid such as a molding lubricant such as zinc stearate. Is added and mixed and kneaded to obtain a kneaded material (compound).
  • the obtained kneaded material is compression-molded by a predetermined mold to obtain a molded body having a shape corresponding to the shape of the bearing 9a.
  • the molding conditions are, for example, molding pressure l to 3 ton / cm, and in the case of iron, for example, the molding pressure may be about 2 to 5 ton / cm2.
  • the obtained compact is sintered in a non-oxidizing atmosphere (reducing gas, inert gas or vacuum) to obtain a sintered body.
  • a non-oxidizing atmosphere reducing gas, inert gas or vacuum
  • the sintering conditions are, for example, a temperature of about 750 to 800 ° C for about 20 to 60 minutes when the metal composition is copper-based, and a temperature of about 1000 to 1200 ° C for an iron-based metal composition. It should be about 20 to 60 minutes.
  • the obtained sintered body is subjected to sizing (recompression) using a predetermined die (finish die), thereby giving appropriate dimensional accuracy and surface finishing, especially the surface of the inner peripheral surface. Finish and adjust the size of the holes.
  • sizing be performed on almost the entire sintered body so that the size of the inner peripheral surface 911 and the size of the pores in the taper portion 93 are substantially the same.
  • the sintered body is impregnated with a predetermined lubricating oil (oil impregnation). This is usually done under reduced pressure.
  • the lubricating oil is impregnated into the pores of the bearing 9a by being connected to each other in a mesh form by capillary action (capillary action).
  • the operation of the bearing 9a when driving the steering motor 1 will be briefly described.
  • the lubricating oil impregnated in the bearing 9 a is sucked out of the shaft support portion 91 by a pumping operation described below based on the rotation of the rotating shaft 61, and also based on frictional heat.
  • the oil oozes out of the shaft support 91 due to a decrease in the viscosity of the lubricating oil and thermal expansion.
  • an oil film is formed on the bearing sliding surface (the joint surface between the bearing 9 a and the rotating shaft 61), that is, on the inner peripheral surface 911 of the shaft support portion 91, and the oil film forms an inner peripheral surface. Friction between the rotating shaft 61 and the rotating shaft 61 is reduced, and the rotating shaft 61 rotates smoothly.
  • FIG. 5 is a view schematically showing the bearing 9a and the rotating shaft 61 when the stepping motor 1 is driven.
  • the rotating shaft 61 starts rotating clockwise in FIG. 5 (rotation)
  • the inner peripheral surface 9 11 1 in FIG. A force acts on the space between the shaft 61 and the lubricating oil to collect.
  • lubricating oil is sucked from a portion of the inner peripheral surface 911 of the shaft supporting portion 91 to which no load is applied from the rotating shaft 61.
  • This lubricating oil adheres to the outer peripheral surface of the rotating shaft 61 and is transported along the inner peripheral surface 911 from the upper side in FIG. 5 to the lower side in FIG. 5, that is, the clockwise direction in FIG.
  • the oil wedge (oil film) 21 generated by the flow of the lubricating oil prevents the inner peripheral surface 9 11 of the shaft support 9 1 from contacting the outer peripheral surface of the rotating shaft 6 1, and the rotating shaft 6 1 is smooth.
  • the hydraulic pressure distribution is as shown in FIG.
  • the lubricating oil permeates the bearing 9a, and in the low oil pressure part, the lubricating oil is sucked out as described above. That is, a pump action occurs, and the lubricating oil circulates.
  • the lubricating oil may flow from the tip of the inner peripheral surface 911 to the tapered portion 93, but the bearing 9a has a tapered portion 93. Therefore, even if the lubricating oil flows out from the tip of the inner peripheral surface 911 to the tapered portion 93, the lubricating oil is generated by capillary action in the gap between the tapered portion 93 and the rotating shaft 61. However, it is sucked into the inner peripheral surface 911 side and again permeates into the inside of the shaft support portion 91. As a result, the consumption of the lubricating oil is suppressed, sufficient oil is always supplied to the inner peripheral surface 911 of the shaft support portion 91, and smooth rotation due to low friction is ensured.
  • the taper portion 93 is formed in the bearing fixing portion 92, the responsiveness of the stepping motor 1 due to an increase in frictional force and self-starting It is possible to suppress the consumption of the lubricating oil impregnated in the bearing 9a without deteriorating the characteristics and the like, and as a result, there is always enough oil on the inner peripheral surface 9 11 of the shaft support 9 1 Supplied, smooth rotation due to low friction is prevented, and the durability of the bearing 9a is also improved.
  • the tapered portion 93 is formed continuously from the distal end of the inner peripheral surface 911, the gap between the base end of the taper portion 93 and the rotating shaft 61 is increased. Even if the lubricating oil flows out of the tip of the inner peripheral surface 911 to the taper portion 93, the lubricating oil can be reduced to the tapered portion 93 and the rotating shaft 61. Due to the capillary phenomenon in the gap between the shaft support portion 91 and the shaft support portion 91, it is surely sucked and held. Next, another embodiment of the bearing of the present invention will be described.
  • FIG. 6 is a sectional view showing another embodiment of the bearing of the present invention.
  • the right side in FIG. 6 is referred to as “distal end”, and the left side is referred to as “base end”.
  • description of common points with the above-described bearing 9a will be omitted, and main differences will be described.
  • a step 97 is formed between the taper portion 93 and the inner peripheral surface 911.
  • the inner diameter of the base end of the tapered portion 93 (the minimum inner diameter of the tapered portion 93) L9 is larger than the diameter L7 of the distal end of the inner peripheral surface 911.
  • the step 97 also contributes to effectively forming a lubricating oil reservoir at the base end of the taper portion 93.
  • the height (L 9 -L 7) / 2 of the step 97 that can effectively exhibit such a function is preferably 0.1 mm or less (for example, about 0.1 restaurant).
  • the tapered portion is formed by the step 97.
  • the contact between the inner peripheral surface of the rotating shaft 61 and the inner peripheral surface of the rotating shaft 61, in particular, the inner peripheral surface of the base end of the tapered portion 93 can be prevented.
  • a bearing 9c may be used instead of the bearing 9a.
  • the bearing 9c and the stepping motor 1 having the bearing 9c similar to the bearing 9a and the stepping motor 1 described above, the response of the stepping motor 1 due to an increase in frictional force, the self-starting characteristic, etc. It is possible to suppress the consumption of the lubricating oil impregnated in the bearing 9c without causing deterioration, so that a sufficient amount of oil is always supplied to the inner peripheral surface 911 of the shaft support section 91. As a result, smooth rotation is ensured due to low friction, and the durability of the bearing 9c is also improved.
  • the steering motor 1 shown in FIG. 1 having the bearing 9a shown in FIG. 3 was manufactured by the method described above.
  • the bearing 9a was sized for substantially the entirety (the inner peripheral surface 911 and the tapered portion 93).
  • the conditions of the stepping motor, bearing and lubricating oil are as follows.
  • the bearing density, effective porosity (oil content), and compressive strength were measured in accordance with JIS Z 2505, JIS Z 2506, and JIS Z 2507, respectively.
  • Axial length LI 2.4 mm
  • Axial length L2 on the tip side from step 96 1.3 dragons
  • the axial length L3 of the inner peripheral surface 9 1 1 0.8 mm
  • Diameter L7 of inner peripheral surface 9 1 1 2.0 mm
  • Average inner diameter of tapered section 93 L8 2.08
  • Lubricating oil Synthetic oil
  • a stepping motor similar to that of Example 1 was manufactured by the same method except that the bearing 9a was replaced with the bearing 9c shown in FIG.
  • the conditions of the bearing are as follows.
  • the conditions of the stepping motor and the lubricating oil are the same as in the first embodiment.
  • Axial length L2 on the tip side from step 96 1.3 mm 98/19072
  • the axial length L3 of the inner peripheral surface 9 1 1 0.8 mm
  • Diameter L7 of inner peripheral surface 9 1 1 2.0 mm
  • Average inner diameter of taper part 9 3 L8 2.28 mm
  • the minimum inner diameter of the tapered portion 9 3 L9 2.2 mm
  • a stepping motor similar to that of Example 1 was manufactured by the same method except that the bearing 9a was replaced with the bearing 100 shown in FIG. In this case, for the bearing 100, only the rotating shaft support 101 was sized.
  • the conditions of the bearing are as follows. The conditions of the stepping motor and the lubricating oil are the same as in the first embodiment.
  • Axial length of rotating shaft support 101 1 L 12 0.5
  • the size of the pores in the enlarged diameter section 102 300 m
  • a steering motor similar to that of Comparative Example 1 was manufactured by the same method except that the axial length L12 of the rotating shaft support 101 was changed to 0.8.
  • the stepping motors of Examples 1 and 2 were all normal at the end of 100,000 cycles, and thus proved to have a long bearing life and high durability.
  • the stepping motor of Comparative Example 1 has a short bearing life and low durability.
  • the stepping motor of Comparative Example 2 has a large frictional resistance at the rotating shaft support portion, and therefore has poorer self-starting characteristics and responsiveness than Examples 1 and 2 and Comparative Example 1.
  • each constituent element of a motor has the same configuration. Anything that can produce a function can be appropriately replaced.
  • two units are used as the stator 2 in order to improve the stability (balance) in the structure and the magnetic circuit.
  • one unit or three or more units are used. It may be used.
  • the use of the motor is not limited to the lens drive for focusing and focusing of the optical system in the various optical devices described above, but also for the drive of a pickup lens of a storage medium such as a DVD. Anything is acceptable.
  • the PM type stepping motor has been described.
  • the motor of the present invention is not limited to this, and may be, for example, a VR type or hybrid type stepping motor.
  • the bearing of the present invention is not limited to the illustrated structure.
  • the bearing fixing portion may have a portion having a constant inner diameter at a part (for example, a tip portion) thereof.
  • the bearing fixing portion has the tapered portion whose inner diameter gradually increases in the direction away from the shaft support portion, the frictional resistance of the rotating shaft is reduced. Without increasing the friction (without deteriorating the motor's responsiveness and self-starting characteristics due to an increase in frictional force), it is possible to suppress the consumption of the lubricating oil impregnated in the bearing. Sufficient oil is supplied to the inner peripheral surface of the support, ensuring smooth rotation due to low friction and improving the durability of the bearing You.
  • the taper angle 0 of the taper portion is 0.5 to 30 °, the lubricating oil that has flowed out to the tapered portion is surely sucked and held on the shaft support portion side by capillary action. can do.
  • the gap between the base end portion of the taper portion and the rotating shaft can be further reduced. Even if the lubricating oil flows out from the inner peripheral surface of the shaft support to the tapered portion, the lubricating oil can be reliably sucked and held on the shaft support by the capillary action.
  • a lubricating oil sump can be effectively formed at the base end of the taper portion, and the lubricating oil can be formed. From the oil reservoir, it is sucked and held on the shaft support part side by capillary action, and again penetrates into the shaft support part, so that sufficient oil is always supplied to the inner peripheral surface of the shaft support part and the circle due to low friction As well as ensuring smooth rotation, the durability of the bearing is further improved.
  • the bearing is fitted (press-fitted) into a predetermined hole and fixed, even if the inner diameter of the tapered portion is reduced, the step difference causes the inner peripheral surface of the taper portion, particularly the base end of the tapered portion. The contact between the inner peripheral surface of the portion and the outer peripheral surface of the rotating shaft can be prevented.
  • the motor of the present invention is suitable for use in driving a pickup lens of a storage medium such as a DVD (Digital Video Disc), and for driving a lens for focusing and zooming in an optical device such as a camera or a video camera.
  • a pickup lens of a storage medium such as a DVD (Digital Video Disc)
  • a lens for focusing and zooming in an optical device such as a camera or a video camera.
  • Example 1 Example 2
  • Example 3 Motor stop No occurrence No occurrence 5% Motor self-starting characteristic failure No occurrence 10% Abnormal noise No occurrence No occurrence 20%
  • Abnormal occurrence of wear powder No occurrence No occurrence 100%

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Sliding-Contact Bearings (AREA)
  • Motor Or Generator Frames (AREA)

Abstract

L'invention se rapporte à un roulement qui limite la consommation d'huile lubrifiante sans augmenter le moment de frottement d'un arbre rotatif, prolongeant ainsi la durée de vie de ce dernier, ainsi qu'à un moteur utilisant un roulement de ce type. Le moteur comprend principalement un stator, un rotor, une plaque de fond, une plaque de montage, une paire de roulements, un support et une vis de commande liée à l'arbre rotatif du moteur. Chaque roulement (9a) représente un palier de glissement qui comprend un boîtier fritté et que l'on utilise lorsqu'il est imprégné d'huile lubrifiante; il comprend un appui de l'arbre (91) possédant une surface périphérique intérieure (911) destinée à soutenir l'arbre rotatif du rotor, et une partie de montage (92) destinée à fixer le roulement (9a) à l'appui du support. Le diamètre de la surface périphérique intérieure (911) est sensiblement constant dans la direction axiale; il est le plus petit des diamètres intérieurs du roulement (9a). La portion de montage (92) comprend une partie concentrique (93) possédant une surface concentrique (931), formée sur son côté périphérique intérieur.
PCT/JP1997/003903 1996-10-25 1997-10-27 Roulement et moteur Ceased WO1998019072A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP8284481A JPH10131967A (ja) 1996-10-25 1996-10-25 軸受けおよびモータ
JP8/284481 1996-10-25

Publications (1)

Publication Number Publication Date
WO1998019072A1 true WO1998019072A1 (fr) 1998-05-07

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Application Number Title Priority Date Filing Date
PCT/JP1997/003903 Ceased WO1998019072A1 (fr) 1996-10-25 1997-10-27 Roulement et moteur

Country Status (2)

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JP (1) JPH10131967A (fr)
WO (1) WO1998019072A1 (fr)

Cited By (1)

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WO2002005846A1 (fr) * 2000-07-05 2002-01-24 Green Cross Vaccine Co., Ltd. Vaccin a combinaison quadrivalente renfermant les anatoxines diphterique et tetanique, l'antigene de surface de la coqueluche et de l'hepatite b et son procede de preparation

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Publication number Priority date Publication date Assignee Title
JP3399368B2 (ja) * 1998-06-29 2003-04-21 セイコーエプソン株式会社 スクリュー付きモータ
JP2000139057A (ja) * 1998-10-30 2000-05-16 Nidec Copal Corp リードスクリュウ付きモータ
DE10025499A1 (de) * 2000-05-23 2001-11-29 Bosch Gmbh Robert Kalibrierte Gleitlagerbuchse und Kalibrierwerkzeug zur Herstellung der Gleitlagerbuchse
JP2004036842A (ja) * 2002-07-05 2004-02-05 Mitsuba Corp 回転軸の軸受構造
JP2004257490A (ja) * 2003-02-26 2004-09-16 Oiles Ind Co Ltd 給脂軸受
KR100646406B1 (ko) * 2005-11-04 2006-11-14 주식회사 만도 벨트식 전동장치를 구비한 자동차의 전기식 동력 보조조향장치
JP2009050149A (ja) * 2007-07-26 2009-03-05 Nidec Sankyo Corp モータ
JP2008059747A (ja) * 2007-10-12 2008-03-13 Clarion Co Ltd ディスクプレーヤ
JP5322813B2 (ja) * 2009-07-14 2013-10-23 京セラドキュメントソリューションズ株式会社 滑り軸受、該滑り軸受を組み込んだ定着ユニット、該定着ユニットを組み込んだ画像形成装置及び滑り軸受を組み込んだシート材搬送ユニット
JP6815110B2 (ja) * 2016-07-13 2021-01-20 日本電産サンキョー株式会社 モータ装置および枠体の製造方法

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JPS4736736Y1 (fr) * 1966-04-20 1972-11-07
JPS5793622U (fr) * 1980-11-29 1982-06-09
JPS6360247B2 (fr) * 1983-08-22 1988-11-24
JPS6430922A (en) * 1987-07-23 1989-02-01 Mitsubishi Metal Corp Sintered oil-contained bearing
JPS6430923A (en) * 1987-07-23 1989-02-01 Mitsubishi Metal Corp Sintered oil-contained bearing

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4736736Y1 (fr) * 1966-04-20 1972-11-07
JPS5793622U (fr) * 1980-11-29 1982-06-09
JPS6360247B2 (fr) * 1983-08-22 1988-11-24
JPS6430922A (en) * 1987-07-23 1989-02-01 Mitsubishi Metal Corp Sintered oil-contained bearing
JPS6430923A (en) * 1987-07-23 1989-02-01 Mitsubishi Metal Corp Sintered oil-contained bearing

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002005846A1 (fr) * 2000-07-05 2002-01-24 Green Cross Vaccine Co., Ltd. Vaccin a combinaison quadrivalente renfermant les anatoxines diphterique et tetanique, l'antigene de surface de la coqueluche et de l'hepatite b et son procede de preparation

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