WO2013042664A1 - Palier en métal fritté et procédé de fabrication de celui-ci - Google Patents

Palier en métal fritté et procédé de fabrication de celui-ci Download PDF

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Publication number
WO2013042664A1
WO2013042664A1 PCT/JP2012/073848 JP2012073848W WO2013042664A1 WO 2013042664 A1 WO2013042664 A1 WO 2013042664A1 JP 2012073848 W JP2012073848 W JP 2012073848W WO 2013042664 A1 WO2013042664 A1 WO 2013042664A1
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WIPO (PCT)
Prior art keywords
powder
sintered bearing
bearing according
copper
copper powder
Prior art date
Application number
PCT/JP2012/073848
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English (en)
Japanese (ja)
Inventor
容敬 伊藤
素直 清水
島津　英一郎
孝洋 奥野
Original Assignee
Ntn株式会社
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
Priority claimed from JP2012018713A external-priority patent/JP6038459B2/ja
Priority claimed from JP2012020858A external-priority patent/JP6038460B2/ja
Priority claimed from JP2012020855A external-priority patent/JP5972588B2/ja
Application filed by Ntn株式会社 filed Critical Ntn株式会社
Priority to CN201280045531.1A priority Critical patent/CN103813874B/zh
Priority to US14/346,447 priority patent/US10081056B2/en
Publication of WO2013042664A1 publication Critical patent/WO2013042664A1/fr
Priority to US16/106,528 priority patent/US11433455B2/en

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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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • 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
    • F16C33/1095—Construction relative to lubrication with solids as lubricant, e.g. dry coatings, powder
    • 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
    • F16C33/12—Structural composition; Use of special materials or surface treatments, e.g. for rust-proofing
    • F16C33/128—Porous bearings, e.g. bushes of sintered alloy
    • 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
    • F16C33/14—Special methods of manufacture; Running-in
    • F16C33/145—Special methods of manufacture; Running-in of sintered porous bearings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • 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
    • F16C2202/00—Solid materials defined by their properties
    • F16C2202/02—Mechanical properties
    • F16C2202/10—Porosity
    • 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
    • F16C2202/00—Solid materials defined by their properties
    • F16C2202/50—Lubricating properties
    • F16C2202/52—Graphite
    • 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
    • F16C2220/00—Shaping
    • F16C2220/20—Shaping by sintering pulverised material, e.g. powder metallurgy

Definitions

  • a sintered bearing excellent in quietness may be used as a bearing for a small precision motor mounted on an information device such as a hard disk drive.
  • this type of sintered bearing is required to improve the limit PV value to PV> 200 MPa ⁇ m / min. Further, it is also necessary to reduce torque fluctuations (improvement of initial conformability), improve durability (improve seizure resistance), improve quietness (improve acoustic characteristics), and the like.
  • Patent Document 2 uses iron-based and copper-based raw material powder, the copper-based raw material powder is a flat powder, segregates copper on the surface side, and moves from the surface side toward the inside.
  • a sliding component in which the ratio of copper is reduced and the ratio of iron is increased is disclosed (claim 1).
  • the copper-based flat powder is segregated to the surface side, the surface side is covered with copper, and from the surface side to the inside
  • a bearing having a concentration gradient in which the ratio of iron is higher than copper is obtained (paragraph 0028).
  • JP 2001-107162 A Japanese Patent No. 3873275
  • Flat copper powder has the property of adhering to the mold forming surface during molding of raw material powder. Therefore, the green compact after molding contains a large amount of copper in the surface layer, while the core portion has a small copper content. Therefore, a surface layer with a high copper content and a base portion with a lower copper content are formed in the sintered body after sintering.
  • the base portion has high strength because the iron structure-copper structure and the copper structures are firmly bonded with a low melting point metal. Accordingly, the strength of the entire bearing is increased and the load resistance can be improved.
  • the base portion occupies most of the volume of the bearing. However, since the copper content in the base portion can be reduced, the amount of copper used in the entire bearing can be reduced and the cost can be reduced.
  • the sintered bearing according to the present invention is prepared by mixing raw material powder containing iron powder, flat copper powder, and low melting point metal powder, filling the mold, and adhering the flat copper powder to the mold surface.
  • the green compact can be compressed to form a green compact, and the green compact can be sintered.
  • the sintering temperature In order to sinter iron in the compacted powder without reacting with carbon, it is desirable to set the sintering temperature to 700 ° C. to 840 ° C. In this case, it is more desirable to sinter in an atmosphere containing no carbon.
  • the wear resistance of the bearing surface may be lowered when the surface layer is worn and the base portion is exposed.
  • the iron structure becomes a two-phase structure of a ferrite phase and a pearlite phase present at the grain boundary of the ferrite phase, and the hard pearlite phase supplements the wear resistance of the ferrite phase, thereby suppressing the bearing surface wear.
  • the pearlite is present at the grain boundaries of the ferrite phase (see FIG. 12).
  • the sintering temperature is 820 ° C. to 900 ° C. Desirably, the temperature is set to ° C. In this case, it is more desirable to sinter in an atmosphere containing carbon.
  • the ratio of the flat copper powder in the raw material powder is 8% by weight or more, a sufficient amount of the flat copper powder can be adhered to the molding surface.
  • the density of the flat copper powder is small, so that it is difficult to solidify when the green compact is formed. Therefore, the moldability of a green compact can be improved by adding copper powder normally and using it together with flat copper powder. Moreover, in order to reduce the aggressiveness with respect to the axis
  • the adhesion of the flat copper powder to the mold surface is further increased. If the ratio of the fluid lubricant to the flat copper powder is too small, the adhesion of the flat copper powder to the mold will be reduced, and the amount of flat copper powder on the mold forming surface will be insufficient. Moreover, when there is too much, flat same powder will adhere and the problem which aggregates will be produced. According to the verification by the present inventors, 0.1 wt% to 0.8 wt%, preferably 0.2 wt% to 0.7 wt% of a fluid lubricant is blended in a weight ratio with respect to the flat copper powder. It was found that the above problems can be solved.
  • fatty acids particularly linear saturated fatty acids are preferred.
  • This type of fatty acid is represented by the general formula C n-1 H 2n-1 COOH.
  • a foil-like solid lubricant powder is added to the raw material powder, the raw material powder is mixed, the primary mixing in which the flat copper powder and the solid lubricant powder are mixed, and then the iron powder and the low melting point It is desirable to divide into secondary mixing in which metal powder is added and mixed.
  • a fluid lubricant is adhered to the flat copper powder before the primary mixing, the adhesion to the foil-like solid lubricant and further the adhesion of the flat copper powder to the mold surface are increased. If the ratio of the fluid lubricant to the flat copper powder is too small, the adhesion of the flat copper powder to the mold will be reduced, and the amount of flat copper powder on the mold forming surface will be insufficient. Moreover, when there is too much, flat copper powder will adhere and the problem which aggregates arises. According to the verification by the present inventors, 0.1 wt% to 0.8 wt%, preferably 0.2 wt% to 0.7 wt% of a fluid lubricant is blended in a weight ratio with respect to the flat copper powder. It was found that the above problems can be solved.
  • fatty acids particularly linear saturated fatty acids are preferred.
  • This type of fatty acid is represented by the general formula C n-1 H 2n-1 COOH.
  • the density of the flat copper powder is small, so that it is difficult to solidify when the green compact is formed. Therefore, the moldability of a green compact can be improved by adding copper powder normally and using it together with flat copper powder. This normal copper powder can be uniformly dispersed in the raw material powder by adding and mixing during secondary mixing.
  • FIG. 5 is an enlarged sectional view of a region Q in FIG. 4. It is an organization chart showing the pearlite structure in steel. It is an expanded sectional view of the area
  • the bearing 1 of the present invention is formed by filling raw material powder mixed with various powders in a mold, compressing this to form a green compact, and then sintering the green compact.
  • Copper powder As the copper powder, two types of foil-like flat copper powder and normal copper powder are used.
  • the flat copper powder is flattened by stamping raw material copper powder made of water atomized powder or the like.
  • “length” and “thickness” refer to the geometric maximum dimension of each flat copper powder 3 as shown in FIG.
  • the apparent density of the flat copper powder is 1.0 g / cm 3 or less. If the flat copper powder has the above size and apparent density, the adhesion of the flat copper powder to the mold forming surface is increased, so that a large amount of flat copper powder can be attached to the mold forming surface.
  • Fluid lubricant In order to attach the flat copper powder to the molding surface, a fluid lubricant is previously attached to the flat copper powder. This fluid lubricant only needs to be attached to the flat copper powder before filling the raw material powder into the mold, and is preferably attached to the raw copper powder before mixing the raw material powder, more preferably at the stage of crushing the raw material copper powder. Let The fluid lubricant may be attached to the flat copper powder by means such as supplying the fluid lubricant to the flat copper powder and stirring it after mixing and before mixing with other raw material powders.
  • the blending ratio of the fluid lubricant to the flat copper powder should be 0.1% by weight or more, and aggregation due to the adhesion of the flat copper powders In order to prevent this, the blending ratio is 0.8 wt% or less. Desirably, the lower limit of the blending ratio is 0.2% by weight or more, and the upper limit is 0.7% by weight.
  • the fluid lubricant fatty acids, particularly linear saturated fatty acids are preferred. This type of fatty acid is represented by the general formula C n-1 H 2n-1 COOH. This fatty acid has a Cn in the range of 12 to 22, and for example, stearic acid can be used as a specific example.
  • the low melting point metal powder is a metal powder having a melting point lower than the sintering temperature.
  • a metal powder having a melting point of 700 ° C. or lower for example, a powder of tin, zinc, phosphorus or the like is used.
  • tin is preferred because it causes less transpiration during sintering. Since these low melting point metal powders have high wettability with respect to copper, liquid phase sintering proceeds by blending with the raw material powder, and the bond strength between the iron structure and the copper structure or between the copper structures is enhanced.
  • the strength of the metal structure increases as the blending amount of the low melting point metal increases, but when the flat copper powder is used as in the present invention, if the amount of the low melting point metal is too large, the flat copper powder becomes spherical as described above, There is a problem that the copper area on the bearing surface is reduced.
  • a low melting point metal of about 10% by weight with respect to copper.
  • the ratio of the melting point metal is less than 10% by weight (desirably 8.0% by weight or less).
  • the raw material powder blended with each of the above powders is copper powder of 18 wt% to 40 wt%, low melting point metal powder (for example, tin powder) of 1 wt% to 4 wt%, solid lubricant powder (for example, graphite powder) Is preferably blended in an amount of 0.5 to 2.5% by weight, with the balance being iron powder.
  • low melting point metal powder for example, tin powder
  • solid lubricant powder for example, graphite powder
  • the compounding ratio of the copper powder is 18% by weight or more, which is the total of both.
  • the proportion of the copper powder exceeds 40% by weight, the content of the iron structure in the base portion is insufficient, and the strength is reduced.
  • the usage-amount of copper powder becomes excessive and the cost merit by using flat copper powder becomes scarce.
  • the blending amount of the copper powder in the raw material powder is 18 wt% or more and 40 wt% or less.
  • the compounding quantity of the flat copper powder in raw material powder shall be 8 to 40 weight%, desirably 8 to 20 weight%.
  • the ratio of the low melting point metal powder is less than 1% by weight, the strength of the bearing cannot be secured, and if it exceeds 4% by weight, the problem of spheroidizing the flat copper powder occurs as described above.
  • the ratio of the solid lubricant powder is less than 0.5% by weight, the friction reducing effect on the bearing surface cannot be obtained, and if it exceeds 2.5% by weight, the strength is reduced.
  • the low melting point metal powder is blended in an amount of 1 to 4% by weight and the solid lubricant powder is blended in an amount of 0.5 to 2.5% by weight.
  • the blending ratio of the low melting point metal powder to the copper powder is preferably less than 10% by weight (desirably 8% by weight or less).
  • FIG. 13 shows a particularly preferable blending ratio of various raw material powders described above.
  • the copper powder is usually 8% by weight to 12% by weight
  • the flat copper powder is 10% by weight to 15% by weight
  • the low melting point metal powder is 1.0% by weight to 2.0% by weight
  • the flat copper powder 3 and the graphite powder 4 adhere to each other and overlap in layers due to the fluid lubricant or the like adhering to the flat copper powder, and the apparent density of the flat copper powder increases. Therefore, it becomes possible to uniformly disperse the flat copper powder in the raw material powder during the secondary mixing. If a lubricant is added separately during the primary mixing, the adhesion between the flat copper powder and the graphite powder is further promoted, so that the flat copper powder can be more uniformly dispersed during the secondary mixing.
  • a powdery lubricant can be used in addition to the same or different fluid lubricant as the fluid lubricant.
  • the above-mentioned forming aid such as metal soap is generally powdery and has a certain degree of adhesion, which can be promoted by adhesion of flat copper powder and graphite powder.
  • the apparent density of the flat copper powder 3 is the smallest.
  • the flat copper powder 3 is a foil shape having the above-mentioned length L and thickness t, and the area of the wide surface per unit weight is large. Therefore, the flat copper powder is easily affected by the adhesive force due to the fluid lubricant adhering to the surface thereof, and further by the coulomb force.
  • the flat copper powder 3 After filling the raw material powder into the mold 6, it is enlarged in FIG. 5.
  • the flat copper powder 3 adheres to the entire area of the molding surface 61 in a layered state in which the wide surface faces the molding surface 61 and a plurality of layers (about 1 to 3 layers) overlap.
  • an endothermic gas obtained by mixing liquefied petroleum gas (butane, propane, etc.) and air and thermally decomposing with a Ni catalyst is used as the sintering atmosphere.
  • the endothermic gas may cause carbon to diffuse and harden the surface, resulting in the same problem.
  • FIG. 7 schematically shows the metal structure near the surface of the sintered bearing 1 (region P in FIG. 1) that has undergone this manufacturing process.
  • the copper structure is hatched, and the dotted pattern is added to the graphite.
  • the green compact 9 is formed in a state in which the flat copper 3 is adhered in a layered manner on the mold forming surface 61, and the layered flat copper 3 is sintered.
  • a surface layer S1 having a high copper concentration is formed on the entire surface including the bearing surface 1a of the bearing 1.
  • the wide surface of the flat copper 3 may have adhered to the molding surface 61, so that most of the copper structure of the surface layer S1 is flat and oriented so that the wide surface faces the surface.
  • the thickness of the surface layer S1 corresponds to the thickness of the flat copper adhering in a layered manner to the mold forming surface 61, and is about 1 ⁇ m to 6 ⁇ m.
  • the area of the copper structure is larger than the area of the iron structure, specifically, 60% or more of the copper structure is the copper structure.
  • the base portion S2 inside the heel surface layer S1 is basically covered with the surface layer S1. As shown in FIG. 8, the copper content in the base portion S2 is less than the copper content in the surface layer S1, and the copper content rapidly decreases when the surface layer S1 moves to the base portion S2. is doing. Further, the copper content (% by weight) in each part of the base part S2 is uniform in each part.
  • the area ratio of the copper structure to the iron structure is 60% or more over the entire surface of the surface layer S1 including the bearing surface 1a. Therefore, the initial conformability and quietness of the sintered bearing 1 can be improved. Further, since all the iron structure contained in the bearing 1 is the ferrite phase ⁇ Fe, even if the surface layer S1 is worn and the iron structure of the base portion S2 appears on the surface, the bearing surface can be softened, Aggressiveness against the axis 2 can be weakened.
  • the base portion S2 inside the surface layer S1 has a hard structure having a small copper content and a high iron content compared to the surface phase S1.
  • the iron content is increased in the base portion S2 that occupies most of the bearing 1, the amount of copper used in the entire bearing 1 can be reduced, and compared with a copper-based sintered bearing. Significant cost reduction can be achieved.
  • the iron structure is the ferrite phase ⁇ Fe. Even in a reduced state, the aggressiveness against the shaft 2 can be weakened, and the durability as a bearing can be ensured. This durability is sufficiently obtained if the content of the copper structure in the base portion S2 is at least 10% by weight or more.
  • the initial conformability, the limit PV value, and the amount of wear are compared between the product of the present invention and the conventional bronze-based sintered bearing and copper-iron-based sintered bearing. A test was conducted.
  • composition (weight ratio) of each bearing in the comparative test was as follows. Invention product: Iron: 80.2%, Copper: 18.0% (flat copper powder 8%), Tin: 1.0%, Graphite 0.8% Bronze bearings: Copper: 88.8%, Tin: 9.9%, Graphite: 1.3% Copper-iron sintered bearings: Iron: 77.2%, Copper: 20.0%, Tin: 2.0%, Graphite 0.8%
  • FIG. 9 shows the results of the initial conformability characteristic measurement test
  • FIG. 10 shows the results of the limit PV value measurement test
  • FIG. 11 shows the results of the wear amount test.
  • the iron structure is entirely formed of a soft ferrite phase.
  • the surface layer is worn due to the use conditions of the bearing (for example, when used at a high surface pressure).
  • the wear resistance of the bearing surface may be insufficient.
  • the iron structure is a two-phase structure consisting of a ferrite phase and a pearlite phase
  • the hard pearlite phase contributes to the improvement of wear resistance, and the wear of the bearing surface under high surface pressure is suppressed and the bearing life is extended. It can be improved (second embodiment). Due to the diffusion of carbon, as shown in FIG. 6, when the proportion of pearlite ⁇ Fe becomes excessive and the proportion is the same level as that of ferrite ⁇ Fe, the aggressiveness of the pearlite against the shaft increases remarkably and the shaft is likely to wear. In order to prevent this, as shown in FIG.
  • the pearlite phase ( ⁇ Fe) is suppressed to the extent that it exists (is scattered) at the grain boundary of the ferrite phase ( ⁇ Fe).
  • the “grain boundary” here means both the grain boundary formed between the ferrite phases and between the ferrite phase and other particles, as well as the crystal grain boundary 10 in the ferrite phase ( ⁇ Fe).
  • the pearlite phase existing at the former grain boundary is represented by ⁇ Fe1
  • the pearlite phase present at the latter grain boundary is represented by ⁇ Fe2.
  • the ratio of the pearlite phase ⁇ Fe ( ⁇ Fe1 + ⁇ Fe2) to the ferrite phase ⁇ Fe is preferably 5 to 20% in an area ratio in an arbitrary cross section of the base portion S2.
  • the growth rate of pearlite mainly depends on the sintering temperature. Therefore, in order for the pearlite phase to be present at the grain boundary of the ferrite phase in the above-described manner, the sintering temperature is raised to about 820 ° C. to 900 ° C. (see FIG. 14) than in the first embodiment, and the furnace Sintering is performed using a gas containing carbon as the inner atmosphere, such as natural gas or endothermic gas (RX gas). As a result, carbon contained in the gas diffuses into iron during sintering, and pearlite phase ⁇ Fe can be formed. When sintered at a temperature exceeding 900 ° C., carbon in the graphite powder reacts with iron.
  • Other configurations, such as the composition of the raw material powder and the manufacturing procedure, are the same as those in the first embodiment, and a duplicate description is omitted.
  • the present invention is not limited to a perfect circle bearing, and the outer circumference of the bearing surface 1a and the shaft 2 is exemplified.
  • the present invention can be similarly applied to a fluid dynamic pressure bearing in which a dynamic pressure generating portion such as a herringbone groove or a spiral groove is provided on the surface.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Powder Metallurgy (AREA)
  • Sliding-Contact Bearings (AREA)

Abstract

Le but de la présente invention est de proposer un palier en métal fritté capable de réduire la quantité de cuivre nécessaire et d'abaisser les coûts de production, tout en présentant d'excellentes caractéristiques de rodage initial et un faible niveau de bruit ainsi qu'une durabilité élevée. On remplit un moule avec une poudre de matériau de départ comprenant de la poudre de fer, une poudre de cuivre plat, une poudre métallique à bas point de fusion et du graphite; et on forme un comprimé en cru dans un état où la poudre de cuivre plat a été déposée sur la face de moulage de la matrice. Le fer à l'intérieur du comprimé en cru est par la suite fritté sans réagir avec le carbone, moyennant quoi une structure en fer se forme dans une phase de ferrite et on obtient un palier en métal fritté. Le palier (1) en métal fritté comporte une partie de base (S2) dans laquelle la teneur en cuivre est uniforme et une couche de surface (S1) recouvrant la surface de la partie de base (S2) et ayant une teneur en cuivre plus forte que la partie de base (S2).
PCT/JP2012/073848 2011-09-22 2012-09-18 Palier en métal fritté et procédé de fabrication de celui-ci WO2013042664A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN201280045531.1A CN103813874B (zh) 2011-09-22 2012-09-18 烧结轴承及其制造方法
US14/346,447 US10081056B2 (en) 2011-09-22 2012-09-18 Sintered bearing and method for manufacturing same
US16/106,528 US11433455B2 (en) 2011-09-22 2018-08-21 Sintered bearing and method for manufacturing same

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP2011207802 2011-09-22
JP2011-207802 2011-09-22
JP2012018713A JP6038459B2 (ja) 2011-09-22 2012-01-31 焼結軸受
JP2012-018713 2012-01-31
JP2012020858A JP6038460B2 (ja) 2012-02-02 2012-02-02 焼結軸受の製造方法
JP2012-020855 2012-02-02
JP2012-020858 2012-02-02
JP2012020855A JP5972588B2 (ja) 2012-02-02 2012-02-02 焼結軸受の製造方法

Related Child Applications (2)

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US14/346,447 A-371-Of-International US10081056B2 (en) 2011-09-22 2012-09-18 Sintered bearing and method for manufacturing same
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JP2014219097A (ja) * 2013-04-09 2014-11-20 Ntn株式会社 焼結軸受の製造方法
US20160138651A1 (en) * 2013-07-22 2016-05-19 Ntn Corporation Sintered bearing and method of manufacturing same
US10536048B2 (en) 2013-03-25 2020-01-14 Ntn Corporation Method for manufacturing sintered bearing, sintered bearing, and vibration motor equipped with same

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JP2010077474A (ja) * 2008-09-25 2010-04-08 Hitachi Powdered Metals Co Ltd 鉄系焼結軸受およびその製造方法
JP2011094167A (ja) * 2009-10-27 2011-05-12 Diamet:Kk 鉄銅系焼結摺動部材およびその製造方法

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JP2010077474A (ja) * 2008-09-25 2010-04-08 Hitachi Powdered Metals Co Ltd 鉄系焼結軸受およびその製造方法
JP2011094167A (ja) * 2009-10-27 2011-05-12 Diamet:Kk 鉄銅系焼結摺動部材およびその製造方法

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Publication number Priority date Publication date Assignee Title
US10536048B2 (en) 2013-03-25 2020-01-14 Ntn Corporation Method for manufacturing sintered bearing, sintered bearing, and vibration motor equipped with same
JP2014219097A (ja) * 2013-04-09 2014-11-20 Ntn株式会社 焼結軸受の製造方法
JP2019031738A (ja) * 2013-04-09 2019-02-28 Ntn株式会社 焼結軸受の製造方法
US20160138651A1 (en) * 2013-07-22 2016-05-19 Ntn Corporation Sintered bearing and method of manufacturing same
US9989092B2 (en) * 2013-07-22 2018-06-05 Ntn Corporation Sintered bearing and method of manufacturing same

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