WO2016157572A1 - Roller bearing having insulation for prevention of electrolytic corrosion, and method for manufacturing same - Google Patents

Roller bearing having insulation for prevention of electrolytic corrosion, and method for manufacturing same Download PDF

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Publication number
WO2016157572A1
WO2016157572A1 PCT/JP2015/076506 JP2015076506W WO2016157572A1 WO 2016157572 A1 WO2016157572 A1 WO 2016157572A1 JP 2015076506 W JP2015076506 W JP 2015076506W WO 2016157572 A1 WO2016157572 A1 WO 2016157572A1
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Prior art keywords
alumina
zirconia
insulating
outer ring
thermal spray
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PCT/JP2015/076506
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French (fr)
Japanese (ja)
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中井　毅
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日本精工株式会社
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Priority claimed from JP2015075200A external-priority patent/JP2015212576A/en
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Publication of WO2016157572A1 publication Critical patent/WO2016157572A1/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
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/62—Selection of substances
    • 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
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/64—Special methods of manufacture
    • 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
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
    • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls

Definitions

  • the present invention relates to an insulating rolling bearing for electrolytic corrosion prevention in which a ceramic insulating layer is formed and a method for manufacturing the same.
  • an insulating rolling for preventing electric corrosion is formed by forming an insulating layer on the outer peripheral surface of the outer ring excluding the outer ring raceway constituting the rolling bearing so that no current flows through the bearing. Bearings are used.
  • a resin layer is also formed as an insulating layer, but it is formed by spraying ceramics from the viewpoint of insulation performance, durability, etc., and droplets of the ceramic material are sprayed from the spray nozzle to a surface other than the raceway surface, that is, Insulating layers having a predetermined thickness are formed by spraying on the outer peripheral surface and both end surfaces of the outer ring and the inner peripheral surface and both end surfaces of the inner ring (see, for example, Patent Documents 1 to 3).
  • the insulation structure can be maintained by impregnating the pores with a sealing agent such as synthetic resin after thermal spraying, curing the synthetic resin and performing sealing treatment. It has been broken.
  • the sealing agent cannot be infiltrated into all the voids, and the insulation resistance value and the breakdown voltage are reduced. Decrease significantly. Further, since the sealing agent also has a function of maintaining the toughness and adhesion of the insulating layer, the strength of the insulating layer and the adhesion with the base material are reduced unless the sealing agent penetrates sufficiently. In addition, cracks may develop starting from a portion having a high porosity. And depending on these causes, peeling may occur in some cases.
  • the insulating coating is made of a mixture of different types of ceramics.
  • different types of ceramic powders are mixed at a predetermined ratio and melted in an electric furnace, cooled and solidified to form an ingot, and the ingot is pulverized.
  • a thermal spray material classified into a predetermined particle size is used.
  • the different components are not uniformly dispersed, and some of the components exist as they are (see FIG. 3).
  • spraying using such a thermal spray material In the obtained sprayed coating, a large number of coarse lumps are dispersed, and a structure in which different components are separated from each other is formed, so that sufficient film strength and film characteristics may not be obtained.
  • an object of the present invention is to form an insulating film having an insulating property and a coating strength that are superior to those of conventional ones and in which there are few variations in an insulating rolling bearing for preventing electrolytic corrosion formed with a ceramic insulating layer.
  • the present invention provides the following insulating rolling bearing for preventing electric corrosion and a method for manufacturing the same.
  • a metal outer ring having an outer ring raceway formed on the inner peripheral surface, a metal inner ring disposed inside the outer ring and having an inner ring raceway formed on the outer peripheral surface, and between the outer ring raceway and the inner ring raceway.
  • Insulating rolling bearing for preventing electric corrosion comprising a plurality of rolling elements each made of metal and capable of rolling, wherein an insulating film is formed on at least one of the outer ring, the inner ring and the rolling elements.
  • the insulating coating contains alumina and zirconia as main components, and zirconia is 5% by mass or more and 40% by mass or less based on the total amount of alumina and zirconia, and the alumina contains ⁇ -alumina and ⁇ -alumina.
  • the zirconia contains at least one of monoclinic zirconia and cubic zirconia.
  • Insulating rolling bearing for preventing electric corrosion comprising a plurality of rolling elements each made of metal and capable of rolling, wherein an insulating film is formed on at least one of the outer ring, the inner ring and the rolling elements.
  • Alumina powder and zirconia powder are used as a raw material powder of a thermal spray material, and a thermal spray coating is formed by spraying a thermal spray material having a zirconia content of 5 mass% to 40 mass% of the total amount of the thermal spray material.
  • a method of manufacturing an insulating rolling bearing for preventing electrical corrosion comprising a plurality of rolling elements each made of metal and capable of rolling, wherein an insulating film is formed on at least one of the outer ring, the inner ring and the rolling elements.
  • the insulating coating formed in the present invention is a sprayed coating in which at least one of cubic zirconia and monoclinic zirconia is mixed in at least one of ⁇ -alumina and ⁇ -alumina, and has excellent insulating performance and variation. It is dense and excellent in film strength. Therefore, it is possible to obtain an insulating rolling bearing for preventing corrosion, which can maintain excellent insulating performance for a long time and has excellent durability.
  • the other component is infused into a lump of one component. It becomes an insulating film in which fine particles are dispersed. Therefore, this insulating film has no coarse particles, has a uniform structure, and is excellent in film strength and film characteristics.
  • FIG. 10 is a graph showing the results of Test 6.
  • 10 is a graph showing the results of Test 7. It is a X-ray-diffraction data of a thermal spray material and an insulating film. It is the electron micrograph which image
  • FIG. 10 is a graph showing the results of Test 8. It is a graph which shows the measurement result of the fracture toughness value of each thermal spray coating of Example 5 and Comparative Example 7 obtained in Test 9. It is a graph which shows the measurement result of the breakdown voltage value of each thermal spray coating of Example 5 and Comparative Example 7 obtained in Test 9. It is the electron micrograph which image
  • the structure of the electric rolling prevention insulating rolling bearing is not limited.
  • the electric rolling prevention insulating rolling bearing shown in FIG. 1 can be exemplified.
  • a plurality of rolling elements 5 are provided between the inner ring raceway 2 formed on the outer peripheral surface of the inner ring 1 and the outer ring raceway 4 formed on the inner peripheral surface of the outer ring 3,
  • An insulating coating 6 is formed on at least the outer peripheral surface of the outer ring 3 on the surface excluding the outer ring raceway surface.
  • a surface of the outer ring 3 other than the surface on which the outer ring raceway surface 4 is formed that is, the outer peripheral surface 7 of the outer ring 3, both axial end surfaces 8 and 8, and the outer peripheral surface 7 and both end surfaces 8 and 8 are continuous.
  • An insulating film 6 is formed over the curved portions 9 and 9.
  • the insulating coating 6 insulates the outer ring 3 from the housing when the outer ring 3 is fitted and supported in a metal housing. As a result, no current flows between the outer ring 3 and the housing, and no electrolytic corrosion occurs on other bearing components.
  • the insulating coating 6 is mainly composed of alumina and zirconia, and zirconia is 5% by mass or more and 40% by mass or less based on the total amount of alumina and zirconia. By setting the zirconia content within this range, the dense insulating coating 6 can be obtained at low cost.
  • the insulating coating 6 has the above composition, but structurally, at least one of cubic zirconia and monoclinic zirconia is mixed in ⁇ -alumina and ⁇ -alumina, and ⁇ -alumina and ⁇ -alumina are mixed. In addition, a mixture of both cubic zirconia and monoclinic zirconia is preferable.
  • a thermal spray material made of alumina containing zirconia is sprayed.
  • the thermal spray coating obtained by thermal spraying becomes the insulating coating 6.
  • ⁇ -alumina is formed in ⁇ -alumina, and monoclinic zirconia and cubic zirconia are mixed there.
  • unmelted ⁇ -alumina particles are reduced and fine ⁇ -alumina is formed, thereby reducing coarse pores along the boundary of unmelted ⁇ -alumina particles and improving film strength. .
  • the insulating coating 6 preferably includes both cubic zirconia and monoclinic zirconia in both ⁇ -alumina and ⁇ -alumina.
  • the alumina in the thermal spray material is high purity, Na 2 O 3 contained as impurities is 0.5 mass% or less, and Fe 2 O 3 is 0%. It is preferable to use high-purity alumina of 1% by mass or less. By using high-purity alumina, the wettability between particles is improved, and densification is further promoted during thermal spraying. As a result, the adhesion between the insulating coating 6 and the base metal is increased, and the insulating performance is improved. Will also be better. Most preferably, the alumina purity is 100%, that is, pure alumina. As the purity of alumina decreases, voids tend to increase.
  • alumina powder preferably high-purity alumina
  • zirconia powder produced by the Bayer method or the like are melted in an oxygen stream in an arc furnace, which is an electric furnace at 1500 ° C. or higher, and cooled. It is preferable to use an ingot obtained by pulverization and sizing. A dense thermal spray material can be obtained by such a manufacturing method. Further, the fineness of the insulating coating 6 is further improved by sizing so as to have an average distribution of 10 to 70 ⁇ m, preferably 20 to 40 ⁇ m.
  • the zirconia powder blended at the above ratio and the alumina powder are mixed while being pulverized, and the obtained mixed powder is dissolved in an electric furnace, cooled and solidified into an ingot, It is preferable to pulverize the ingot and classify it to the above particle size.
  • a mixing device for mixing while pulverizing a mixer filled with pulverizing media, for example, a bead mill, a ball mill, an attritor or the like can be used.
  • thermal spraying such a thermal spray material improves the fluidity of the powder, prevents the particles from being broken, and allows thermal spraying without entraining atmospheric oxygen in the thermal spray coating.
  • the number of vacancies is greatly reduced and becomes denser.
  • the insulating performance of the insulating coating 6 is improved and the quality is stabilized.
  • the thickness of the insulating coating 6 is not limited, and is about 100 to 500 ⁇ m as in the conventional case.
  • thermal spraying is performed so that the porosity of the obtained thermal spray coating is 2% or more and 10% or less.
  • the porosity is in the range of 2% or more and 10% or less, the strength is high, the strength is not greatly different, and the variation is small.
  • the porosity around 5% is preferable because of higher strength.
  • the porosity is less than 2% or exceeds 10%, the strength decreases and the variation in strength also increases. In general, it is considered that the smaller the porosity, the denser and higher the thermal spray coating is. However, the film strength is low even when the porosity is less than 2%, and the film strength decreases as it approaches 0%. It is impossible to think from conventional knowledge.
  • the porosity can be controlled by the thermal spraying conditions.
  • the thermal spraying conditions are determined in advance by preliminary experiments so that the porosity is 2% or more and 10% or less, preferably around 5%. ).
  • the porosity can be controlled to 2% or more and 10% or less by plasma spraying in the atmosphere.
  • a sealing treatment may be performed in the same manner as in the past.
  • the insulating coating 6 by thermal spraying is dense and has fewer pores than before, so that the pores can be reliably filled by this sealing treatment, and excellent insulation performance is ensured. Can do.
  • an organic sealing agent containing an acrylic resin, an epoxy resin, a fluororesin, a phenol resin, a polyester resin, or a resin in which these are combined (ester-based, acrylic-based, epoxy-based, Methacrylate type, silicone type and polyester type) are preferred.
  • Test 1 On the outer peripheral surface of the outer ring constituting the single row deep groove type ball bearing of the identification number “6316” (outer diameter: 170 mm, inner diameter: 80 mm, width: 39 mm), the alumina purity is different as shown in Table 1, and zirconia is 20 A thermal spray material (average particle size: 25 ⁇ m) containing alumina is formed by plasma spraying, and then the spray coating is subjected to sealing treatment to prepare a test specimen. For comparison, a test specimen was prepared using an alumina-1% titania commercial thermal spray material as the thermal spray material. Moreover, as shown in FIG.
  • the test body before sealing treatment was cut
  • the porosity was determined by the procedure. (1) Using a digital microscope, capture a cross-sectional image of the test piece into a personal computer. (2) The captured image is binarized with an appropriate threshold (converted into two colors of black and white). (3) The area of the black part is counted as a pore, and the porosity is calculated from “black part area / measurement range area”. (4) This work is performed at 12 locations per test piece, and the average value is calculated.
  • the porosity is as low as 2% or less, and the purity of alumina is low It can be seen that the lower the porosity, the higher the porosity. Moreover, it turns out that the sprayed coating of an Example is dense also compared with a commercially available spraying material.
  • Test 2 The thermal spray material used in Test 1 was sprayed onto the SUJ2 block as the outer ring material, and the adhesion of the thermal spray coating was measured.
  • the method for measuring the adhesion force is shown in FIG. 6. After using a pair of SUJ2 blocks (base materials) on which a thermal spray coating is formed, the thermal spray coatings are bonded to each other with an epoxy adhesive and then pulled in opposite directions to form a thermal spray coating. The tensile force peeled from the base material was measured.
  • Test 3 The insulation resistance value of the outer ring of the test bearing produced in Test 1 was measured.
  • Fig. 8 shows how to measure the insulation resistance value.
  • An annular jig is attached to the outer circumference of the outer ring of the test bearing with tightening bolts, and the line of the insulation resistance measuring machine is connected to the inner diameter of the outer ring collar and the jig. The insulation resistance value was measured.
  • a ground wire was connected to the jig.
  • Test 4 The fracture toughness value of the specimen prepared in Test 1 was measured according to the IF method described in JIS R 1607-1990. The results are shown in FIG. 10, and it can be seen that the fracture toughness value is high by using high-purity alumina powder as in the Examples, and the fracture toughness value decreases as the purity of alumina decreases. Moreover, even if it compares with a commercially available spray material, it turns out that the thermal spray coating of an Example has a high fracture toughness value.
  • Test 5 As shown in Table 2, the zirconia content is different on the outer peripheral surface of the outer ring constituting the single row deep groove type ball bearing (outer diameter: 170 mm, inner diameter: 80 mm, width: 39 mm) of the identification number “6316”, and the remainder is A thermal spray material (Na 2 O 3 in alumina: 0.5 mass%, Fe 2 O 3 : 0.1 mass%, average particle size: 25 ⁇ m), which is alumina, is plasma sprayed, and then subjected to a sealing treatment and tested. The body was made. For comparison, a test specimen was prepared using an alumina-1% titania commercial thermal spray material as the thermal spray material. And the porosity of the sprayed coating was measured in the same manner as in Test 1.
  • Test 6 About the test body produced in Test 5, the adhesion of the sprayed coating was measured in the same manner as in Test 2. The results are shown in FIG. 12, which shows a good correlation with the porosity of Test 5, and the adhesion strength decreases as the porosity of the sprayed coating increases.
  • Test 7 The insulation resistance value of the test body prepared in Test 5 was measured in the same manner as in Test 3. The results are shown in FIG. 13, and the insulation resistance value is high when the zirconia content is in the range of 5 to 40% by mass as in the example, and the thermal spray coating of the example has an insulation resistance value even compared to the commercially available thermal spray material. Is high.
  • the thermal spray raw material used in Example 1 and the obtained thermal spray coating were analyzed by X-ray diffraction.
  • the X-ray diffraction pattern is shown in FIG. 14, where the horizontal axis indicates the diffraction angle (2 ⁇ ) and the vertical axis indicates the diffraction intensity.
  • the thermal spray material consists of ⁇ -alumina and monoclinic zirconia.
  • ⁇ -alumina and cubic zirconia are produced in the sprayed coating, and ⁇ -alumina and single crystal zirconia are formed. Mixed with oblique crystal-zirconia. It can also be seen from the diffraction intensity on the vertical axis that ⁇ -alumina decreases as ⁇ -alumina (portion enclosed by an ellipse) is generated.
  • FIG. 15 shows an electron micrograph of the thermal spray material used in Example 1 and the appearance of a commercially available thermal spray material. It can be seen that the thermal spray material of Example 1 is denser.
  • Test 8 The thermal spray material containing 20% zirconia and the balance being alumina is applied to the outer peripheral surface and both end surfaces of the outer ring constituting the single row deep groove ball bearing (outer diameter: 170 mm, inner diameter: 80 mm, width: 39 mm) of nominal number 6316. Then, plasma spraying was performed under different spraying conditions (see FIG. 1) to form films with different porosity. The film thickness of each film was fixed to 200 ⁇ m by processing and polishing. After thermal spraying, the porosity was determined in the same manner as in Test 1 above.
  • a sealing agent containing an acrylic resin was applied to the coating, dried and subjected to sealing treatment to obtain a test body, and the fracture toughness value of the coating was measured to examine the relationship with the porosity. Fracture toughness values were measured at five locations on the coating for each specimen.
  • the porosity when the porosity is less than 2% or exceeds 10%, the strength is lower than the porosity of 2% or more and 10% or less, and as the porosity approaches 0%, or the porosity The greater the rate, the greater the decrease in strength. Moreover, the difference between the minimum value and the maximum value is large, and the variation is large.
  • Example 5 is about twice as high as the thermal spray coating of Comparative Example 7.
  • an insulating coating is formed only on the outer ring of the bearing.
  • a similar insulating coating may be formed on the inner ring or the rolling element, and all of the outer ring, the inner ring and the rolling element may be formed.
  • An insulating film may be formed.
  • the insulating rolling bearing for preventing electric corrosion of the present invention is excellent in film strength and insulating properties of the insulating coating, it is useful as a bearing for supporting a rotating shaft of an electric motor, a generator or the like.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Rolling Contact Bearings (AREA)
  • Coating By Spraying Or Casting (AREA)

Abstract

Provided is a roller bearing having insulation for prevention of electrolytic corrosion in which at least one of rolling elements, an outer race, and an inner race which are made of metal is coated with an insulating coating film containing alumina and zirconia as main components, wherein zirconia is in the range of 5-40 mass% relative to the total amount of alumina and zirconia, alumina contains α-alumina and γ-alumina, and zirconia contains at least one of monoclinic zirconia and cubic zirconia.

Description

電食防止用絶縁転がり軸受及びその製造方法Insulated rolling bearing for preventing electrolytic corrosion and method for manufacturing the same
　本発明は、セラミックス製の絶縁層が形成された電食防止用絶縁転がり軸受及びその製造方法に関する。 The present invention relates to an insulating rolling bearing for electrolytic corrosion prevention in which a ceramic insulating layer is formed and a method for manufacturing the same.
　電動モータや発電機等、各種電気機器等の回転軸を支承する転がり軸受では、軸受自体に帰路電流やモータ軸電流等の電流が流れてしまう。転がり軸受に電流が流れた場合、電流の通路となる部分に電食が発生して、転がり軸受の寿命を著しく短縮してしまう。このような電食の発生を防止するため、例えば、転がり軸受を構成する外輪の外輪軌道を除いた外周面に絶縁層を形成して軸受に電流が流れないようにした電食防止用絶縁転がり軸受が使用されている。 In a rolling bearing that supports a rotating shaft of various electric devices such as an electric motor and a generator, a current such as a return current or a motor shaft current flows through the bearing itself. When a current flows through the rolling bearing, electrolytic corrosion occurs in a portion serving as a current path, and the life of the rolling bearing is remarkably shortened. In order to prevent the occurrence of such electric corrosion, for example, an insulating rolling for preventing electric corrosion is formed by forming an insulating layer on the outer peripheral surface of the outer ring excluding the outer ring raceway constituting the rolling bearing so that no current flows through the bearing. Bearings are used.
　絶縁層として、樹脂層も形成されているが、絶縁性能や耐久性等からセラミックスを溶射して形成することが行われており、溶射ノズルからセラミックス材料の溶滴を軌道面以外の面、即ち、外輪の外周面及び両端面、内輪の内周面及び両端面に噴射して所定厚さの絶縁層を形成している（例えば、特許文献１～３参照）。 A resin layer is also formed as an insulating layer, but it is formed by spraying ceramics from the viewpoint of insulation performance, durability, etc., and droplets of the ceramic material are sprayed from the spray nozzle to a surface other than the raceway surface, that is, Insulating layers having a predetermined thickness are formed by spraying on the outer peripheral surface and both end surfaces of the outer ring and the inner peripheral surface and both end surfaces of the inner ring (see, for example, Patent Documents 1 to 3).
　また、セラミックス材料を溶射して形成した絶縁層には多数の空孔が発生しており、空孔の分布にもバラツキがある。このような空孔があると、絶縁性能が悪化し、大気中の水分が空孔に侵入すると、更に劣化が進行する。絶縁性能が悪化してそのままでは使用できないため、溶射後に空孔内に合成樹脂等の封孔剤を含浸させ、合成樹脂を硬化させて封孔処理を行うことにより絶縁構造を維持することが行われている。 In addition, a large number of holes are generated in the insulating layer formed by spraying a ceramic material, and the distribution of the holes also varies. If there are such vacancies, the insulation performance deteriorates, and further deterioration proceeds when moisture in the atmosphere enters the vacancies. Since the insulation performance deteriorates and cannot be used as it is, the insulation structure can be maintained by impregnating the pores with a sealing agent such as synthetic resin after thermal spraying, curing the synthetic resin and performing sealing treatment. It has been broken.
日本国特許第４７９５８８８号公報Japanese Patent No. 4795888 日本国特許第４９２００６６号公報Japanese Patent No. 4920066 日本国特許第４８２６４２７号公報Japanese Patent No. 4826427
　しかしながら、封孔処理を行っても、溶射して得た絶縁層の空孔の発生量が多いと、空孔の全てに封止剤を浸透させることはできず、絶縁抵抗値及び破壊電圧が大きく低下する。また、封孔剤は絶縁層の靭性や密着力を維持する働きもあるため、封孔剤が十分に浸透しないと絶縁層の強度及び母材との密着力が低下する。また、空孔率が大きい箇所を起点にして亀裂が進展することもある。そして、これら原因により、場合によっては剥離に至ることがある。 However, even if the sealing treatment is performed, if the amount of generated voids in the insulating layer obtained by thermal spraying is large, the sealing agent cannot be infiltrated into all the voids, and the insulation resistance value and the breakdown voltage are reduced. Decrease significantly. Further, since the sealing agent also has a function of maintaining the toughness and adhesion of the insulating layer, the strength of the insulating layer and the adhesion with the base material are reduced unless the sealing agent penetrates sufficiently. In addition, cracks may develop starting from a portion having a high porosity. And depending on these causes, peeling may occur in some cases.
　また、絶縁被膜が異種のセラミックスの混合物からなる場合もあるが、従来では、異種のセラミックス粉末をそのまま所定割合で混合して電気炉で溶解し、冷却凝固してインゴットとし、インゴットを粉砕して所定の粒径に分級した溶射材料を使用している。しかし、従来の溶射材料は、異種の成分同士が均一に分散せずに、一部、各成分が単体のまま存在しており（図３参照）、このような溶射材料を用いて溶射すると、得られる溶射被膜において、粗大な塊が多数分散するなど、異種の成分同士が分離した組織を形成して十分な膜強度や膜特性が得られないことがある。 In some cases, the insulating coating is made of a mixture of different types of ceramics. Conventionally, different types of ceramic powders are mixed at a predetermined ratio and melted in an electric furnace, cooled and solidified to form an ingot, and the ingot is pulverized. A thermal spray material classified into a predetermined particle size is used. However, in the conventional thermal spray material, the different components are not uniformly dispersed, and some of the components exist as they are (see FIG. 3). When spraying using such a thermal spray material, In the obtained sprayed coating, a large number of coarse lumps are dispersed, and a structure in which different components are separated from each other is formed, so that sufficient film strength and film characteristics may not be obtained.
　そこで本発明は、セラミックス製の絶縁層を形成した電食防止用絶縁転がり軸受において、絶縁特性及び被膜強度が従来よりも優れ、かつ、バラツキの少ない絶縁膜を形成することを目的とする。 Therefore, an object of the present invention is to form an insulating film having an insulating property and a coating strength that are superior to those of conventional ones and in which there are few variations in an insulating rolling bearing for preventing electrolytic corrosion formed with a ceramic insulating layer.
　上記課題を解決するために本発明は、下記の電食防止用絶縁転がり軸受及びその製造方法を提供する。
（１）内周面に外輪軌道を形成した金属製の外輪と、この外輪の内側に配置され、外周面に内輪軌道を形成した金属製の内輪と、これら外輪軌道と内輪軌道との間に転動自在に設けられた、それぞれが金属製である複数個の転動体とを備え、前記外輪、前記内輪及び前記転動体の少なくとも１つに絶縁被膜が形成された電食防止用絶縁転がり軸受において、
　前記絶縁被膜が、アルミナとジルコニアとを主成分とし、かつ、ジルコニアがアルミナとジルコニアとの総量に対し５質量％以上４０質量％以下であり、前記アルミナはα－アルミナとγ－アルミナを含有し、前記ジルコニアは単斜晶ジルコニアと立方晶ジルコニアの少なくとも一方を含有することを特徴とする電食防止用絶縁転がり軸受。
（２）γ－アルミナとα－アルミナとの比率が、Ｘ線回折ピーク比で、γ－アルミナ：α－アルミナ＝１：９以上７：３以下であることを特徴とする上記（１）記載の電食防止用絶縁転がり軸受。
（３）前記絶縁被膜の空孔率が２％以上１０％以下であることを特徴とする上記（１）または（２）記載の電食防止用絶縁転がり軸受。
（４）前記絶縁層の空孔が、合成樹脂で封孔されていることを特徴とする上記（１）～（３）の何れか１項に記載の電食防止用絶縁転がり軸受。
（５）内周面に外輪軌道を形成した金属製の外輪と、この外輪の内側に配置され、外周面に内輪軌道を形成した金属製の内輪と、これら外輪軌道と内輪軌道との間に転動自在に設けられた、それぞれが金属製である複数個の転動体とを備え、前記外輪、前記内輪及び前記転動体の少なくとも１つに絶縁被膜が形成された電食防止用絶縁転がり軸受を製造する方法において、
　アルミナ粉末とジルコニア粉末とを溶射材の原料粉末とし、かつ、ジルコニアの含有量が前記溶射材全量の５質量％以上４０質量％以下である溶射材料を溶射して溶射被膜を形成することを特徴とする電食防止用絶縁転がり軸受の製造方法。
（６）前記溶射被膜を形成した後、合成樹脂を含有する封孔剤により封孔処理することを特徴とする上記（５）記載の電食防止用絶縁転がり軸受の製造方法。
（７）前記アルミナ粉末が、Ｎａ２Ｏ３：０．５質量％以下、Ｆｅ２Ｏ３：０．１質量％以下の高純度アルミナであることを特徴とする上記（５）または（６）記載の電食防止用絶縁転がり軸受の製造方法。
（８）前記アルミナ粉末とジルコニア粉末とを粉砕しながら混合して混合粉末とし、前記混合粉末を１５００℃以上の電気炉にて酸素気流中で溶解し、冷却して得たインゴットを粉砕し、１０～７０μｍに整粒して得た溶射材料を溶射することを特徴とする上記（５）～（７）の何れか１項に記載の電食防止用絶縁転がり軸受の製造方法。 In order to solve the above problems, the present invention provides the following insulating rolling bearing for preventing electric corrosion and a method for manufacturing the same.
(1) A metal outer ring having an outer ring raceway formed on the inner peripheral surface, a metal inner ring disposed inside the outer ring and having an inner ring raceway formed on the outer peripheral surface, and between the outer ring raceway and the inner ring raceway. Insulating rolling bearing for preventing electric corrosion, comprising a plurality of rolling elements each made of metal and capable of rolling, wherein an insulating film is formed on at least one of the outer ring, the inner ring and the rolling elements. In
The insulating coating contains alumina and zirconia as main components, and zirconia is 5% by mass or more and 40% by mass or less based on the total amount of alumina and zirconia, and the alumina contains α-alumina and γ-alumina. The zirconia contains at least one of monoclinic zirconia and cubic zirconia.
(2) The above description (1), wherein the ratio of γ-alumina to α-alumina is X-ray diffraction peak ratio and is γ-alumina: α-alumina = 1: 9 to 7: 3 Insulating rolling bearing for preventing electric corrosion.
(3) The insulating rolling bearing for preventing electrolytic corrosion according to (1) or (2) above, wherein the insulating coating has a porosity of 2% to 10%.
(4) The insulating rolling bearing for electrolytic corrosion prevention according to any one of (1) to (3) above, wherein the holes of the insulating layer are sealed with a synthetic resin.
(5) A metal outer ring having an outer ring raceway formed on the inner peripheral surface, a metal inner ring disposed inside the outer ring and having an inner ring raceway formed on the outer peripheral surface, and between the outer ring raceway and the inner ring raceway. Insulating rolling bearing for preventing electric corrosion, comprising a plurality of rolling elements each made of metal and capable of rolling, wherein an insulating film is formed on at least one of the outer ring, the inner ring and the rolling elements. In the method of manufacturing
Alumina powder and zirconia powder are used as a raw material powder of a thermal spray material, and a thermal spray coating is formed by spraying a thermal spray material having a zirconia content of 5 mass% to 40 mass% of the total amount of the thermal spray material. A method of manufacturing an insulating rolling bearing for preventing electrical corrosion.
(6) The method for producing an insulating rolling bearing for preventing electric corrosion according to (5) above, wherein after the sprayed coating is formed, sealing treatment is performed with a sealing agent containing a synthetic resin.
(7) The above (5) or (6), wherein the alumina powder is high-purity alumina of Na 2 O 3 : 0.5% by mass or less and Fe 2 O 3 : 0.1% by mass or less. The manufacturing method of the insulation rolling bearing for electric corrosion prevention of description.
(8) The alumina powder and the zirconia powder are mixed while being pulverized to form a mixed powder, the mixed powder is dissolved in an oxygen stream in an electric furnace at 1500 ° C. or higher, and cooled to crush the ingot obtained. The method for producing an insulating rolling bearing for preventing electrolytic corrosion according to any one of the above (5) to (7), wherein a thermal spray material obtained by adjusting the particle size to 10 to 70 μm is sprayed.
　本発明で形成する絶縁被膜は、γ－アルミナ及びα－アルミナの少なくとも一方に、立方晶ジルコニア及び単斜晶ジルコニアの少なくとも一方が混在した溶射膜であり、優れた絶縁性能を有するとともに、バラツキもなく、緻密で膜強度にも優れる。そのため、優れた絶縁性能を長期間維持でき、耐久性に優れた電食防止用絶縁転がり軸受が得られる。 The insulating coating formed in the present invention is a sprayed coating in which at least one of cubic zirconia and monoclinic zirconia is mixed in at least one of γ-alumina and α-alumina, and has excellent insulating performance and variation. It is dense and excellent in film strength. Therefore, it is possible to obtain an insulating rolling bearing for preventing corrosion, which can maintain excellent insulating performance for a long time and has excellent durability.
　また、アルミナ粉末とジルコニア粉末とを粉砕しながら混合した混合粉末を溶解、冷却して得たインゴットを整粒した溶射材料を溶射することにより、一方の成分の塊の中に、他方の成分の微細な粒子が分散した絶縁被膜となる。そのため、この絶縁被膜は、粗大粒子が無く、組織が均一で、膜強度及び膜特性により優れたものとなる。 In addition, by spraying a sprayed material obtained by sizing an ingot obtained by melting and cooling a mixed powder obtained by pulverizing alumina powder and zirconia powder, the other component is infused into a lump of one component. It becomes an insulating film in which fine particles are dispersed. Therefore, this insulating film has no coarse particles, has a uniform structure, and is excellent in film strength and film characteristics.
本発明の電食防止用絶縁転がり軸受の一例を示す断面図である。It is sectional drawing which shows an example of the insulated rolling bearing for electric corrosion prevention of this invention. 本発明の製造方法で得られた溶射材料を撮影した電子顕微鏡写真である。It is the electron micrograph which image | photographed the thermal spray material obtained with the manufacturing method of this invention. 従来の製造方法で得られた溶射材料を撮影した電子顕微鏡写真である。It is the electron micrograph which image | photographed the thermal spray material obtained with the conventional manufacturing method. 絶縁被膜の気孔率の測定方法を説明するための模式図である。It is a schematic diagram for demonstrating the measuring method of the porosity of an insulating film. 試験１の結果を示すグラフである。6 is a graph showing the results of Test 1. 絶縁被膜の密着力の測定方法を説明するための模式図である。It is a schematic diagram for demonstrating the measuring method of the adhesive force of an insulating film. 試験２の結果を示すグラフである。6 is a graph showing the results of Test 2. 絶縁抵抗の測定方法を説明するための模式図である。It is a schematic diagram for demonstrating the measuring method of insulation resistance. 試験３の結果を示すグラフである。10 is a graph showing the results of Test 3. 試験４の結果を示すグラフである。10 is a graph showing the results of Test 4. 試験５の結果を示すグラフである。10 is a graph showing the results of Test 5. 試験６の結果を示すグラフである。10 is a graph showing the results of Test 6. 試験７の結果を示すグラフである。10 is a graph showing the results of Test 7. 溶射材料及び絶縁被膜のＸ線回折データである。It is a X-ray-diffraction data of a thermal spray material and an insulating film. 市販溶射材及び実施例１で用いた溶射材料の外観を撮影した電子顕微鏡写真である。It is the electron micrograph which image | photographed the external appearance of the commercially available thermal spray material and the thermal spray material used in Example 1. FIG. 試験８の結果を示すグラフである。10 is a graph showing the results of Test 8. 試験９で得られた、実施例５及び比較例７の各溶射被膜の破壊靭性値の測定結果を示すグラフである。It is a graph which shows the measurement result of the fracture toughness value of each thermal spray coating of Example 5 and Comparative Example 7 obtained in Test 9. 試験９で得られた、実施例５及び比較例７の各溶射被膜の破壊電圧値の測定結果を示すグラフである。It is a graph which shows the measurement result of the breakdown voltage value of each thermal spray coating of Example 5 and Comparative Example 7 obtained in Test 9. 試験９で得られた、実施例５及び比較例７の各溶射被膜の断面組織を撮影した電子顕微鏡写真である。It is the electron micrograph which image | photographed the cross-sectional structure | tissue of each thermal spray coating of Example 5 and Comparative Example 7 obtained by Test 9. FIG.
　以下、本発明に関して図面を参照して詳細に説明する。 Hereinafter, the present invention will be described in detail with reference to the drawings.
　本発明において、電食防止用絶縁転がり軸受の構造には制限はなく、例えば図１に示す電食防止用絶縁転がり軸受を例示することができる。図示される電食防止用絶縁転がり軸受では、内輪１の外周面に形成した内輪軌道２と、外輪３の内周面に形成した外輪軌道４との間に複数の転動体５を設けるとともに、外輪軌道面を除く表面のうち、少なくとも外輪３の外周面に絶縁被膜６が形成されている。好ましくは、外輪３の外輪軌道面４を形成した面以外の面、即ちその外輪３の外周面７、軸方向の両端面８，８、並びに外周面７と両端面８，８とを連続する湾曲部９，９にかけて絶縁被膜６が形成されている。このような電食防止用絶縁転がり軸受では、外輪３を金属製のハウジングに内嵌支持した状態では、絶縁被膜６が外輪３とハウジングとを絶縁する。その結果、外輪３とハウジングとの間に電流が流れなくなり、他の軸受構成部材に電食が発生しなくなる。 In the present invention, the structure of the electric rolling prevention insulating rolling bearing is not limited. For example, the electric rolling prevention insulating rolling bearing shown in FIG. 1 can be exemplified. In the illustrated insulating rolling bearing for preventing electric corrosion, a plurality of rolling elements 5 are provided between the inner ring raceway 2 formed on the outer peripheral surface of the inner ring 1 and the outer ring raceway 4 formed on the inner peripheral surface of the outer ring 3, An insulating coating 6 is formed on at least the outer peripheral surface of the outer ring 3 on the surface excluding the outer ring raceway surface. Preferably, a surface of the outer ring 3 other than the surface on which the outer ring raceway surface 4 is formed, that is, the outer peripheral surface 7 of the outer ring 3, both axial end surfaces 8 and 8, and the outer peripheral surface 7 and both end surfaces 8 and 8 are continuous. An insulating film 6 is formed over the curved portions 9 and 9. In such an electric rolling prevention insulating rolling bearing, the insulating coating 6 insulates the outer ring 3 from the housing when the outer ring 3 is fitted and supported in a metal housing. As a result, no current flows between the outer ring 3 and the housing, and no electrolytic corrosion occurs on other bearing components.
　絶縁被膜６は、アルミナとジルコニアとを主成分とし、かつ、ジルコニアがアルミナとジルコニアとの総量に対し５質量％以上４０質量％以下である。ジルコニア含有量をこの範囲にすることにより、低コストで、かつ、緻密な絶縁被膜６が得られる。 The insulating coating 6 is mainly composed of alumina and zirconia, and zirconia is 5% by mass or more and 40% by mass or less based on the total amount of alumina and zirconia. By setting the zirconia content within this range, the dense insulating coating 6 can be obtained at low cost.
　また、絶縁被膜６は上記組成からなるが、構造的には、γ－アルミナ及びα－アルミナに、立方晶ジルコニア及び単斜晶ジルコニアの少なくとも一方が混在しており、γ－アルミナとα－アルミナに、立方晶ジルコニアと単斜晶ジルコニアの両方が混在したものが好ましい。 The insulating coating 6 has the above composition, but structurally, at least one of cubic zirconia and monoclinic zirconia is mixed in γ-alumina and α-alumina, and γ-alumina and α-alumina are mixed. In addition, a mixture of both cubic zirconia and monoclinic zirconia is preferable.
　本発明では、絶縁被膜６を形成するために、ジルコニアを含有するアルミナからなる溶射材料を溶射する。溶射して得られる溶射被膜が、絶縁被膜６となる。その際、α－アルミナ中にγ－アルミナが生成し、そこへ単斜晶ジルコニアや立方晶ジルコニアが混在する。そして、未溶融のα－アルミナ粒子が少なくなり、微細なγ－アルミナが生成することにより、未溶融のα－アルミナ粒子の境界部に沿った粗大な空孔が減少し、膜強度が向上する。また、絶縁被膜６のγ－アルミナとα－アルミナの比率をＸＤＲ分析にてピーク比から算出すると、分析角度:２θ=４０°－５０°にて、（γ－アルミナ／（γ－アルミナ＋α－アルミナ））×１００）の式から両者の比を求めれば、γ－アルミナとα‐アルミナの比率は、γ－アルミナ：α－アルミナ＝１：９以上７：３以下であることがわかる。γ－アルミナとα－アルミナの比率が、γ－アルミナ：α－アルミナ＝１：９未満もしくは７：３を越えると、被膜強度が低くなる。更に、結晶系が異なる単斜晶ジルコニアや立方晶ジルコニアが混在することにより、内部応力が作用して膜強度がより向上する。そのため、上記のように、絶縁被膜６は、γ－アルミナとα－アルミナの両方に、立方晶ジルコニアと単斜晶ジルコニアの両方が混在することが好ましい。 In the present invention, in order to form the insulating coating 6, a thermal spray material made of alumina containing zirconia is sprayed. The thermal spray coating obtained by thermal spraying becomes the insulating coating 6. At that time, γ-alumina is formed in α-alumina, and monoclinic zirconia and cubic zirconia are mixed there. Then, unmelted α-alumina particles are reduced and fine γ-alumina is formed, thereby reducing coarse pores along the boundary of unmelted α-alumina particles and improving film strength. . Further, when the ratio of γ-alumina and α-alumina in the insulating coating 6 is calculated from the peak ratio by XDR analysis, the analysis angle is 2θ = 40 ° -50 °, and (γ-alumina / (γ-alumina + α- If the ratio of both is obtained from the formula of alumina)) × 100), the ratio of γ-alumina and α-alumina is found to be γ-alumina: α-alumina = 1: 9 to 7: 3. When the ratio of γ-alumina to α-alumina is less than γ-alumina: α-alumina = 1: 9 or exceeds 7: 3, the coating strength is lowered. Furthermore, when monoclinic zirconia and cubic zirconia having different crystal systems are mixed, internal stress acts to further improve the film strength. Therefore, as described above, the insulating coating 6 preferably includes both cubic zirconia and monoclinic zirconia in both γ-alumina and α-alumina.
　また、絶縁被膜６の緻密性を向上させるために、溶射材料中のアルミナは高純度であることが好ましく、不純物として含有するＮａ２Ｏ３が０．５質量％以下、Ｆｅ２Ｏ３が０．１質量％以下の高純度アルミナを用いることが好ましい。純度の高いアルミナを使用することにより、粒子同士の濡れ性が向上して溶射の際に緻密化がより促進され、その結果、絶縁被膜６と母材金属との密着性が高まり、絶縁性能にも優れるようになる。尚、最も好ましくはアルミナ純度が１００％、即ち純アルミナである。アルミナの純度が低くなるほど、空孔が増加する傾向となる． In order to improve the denseness of the insulating coating 6, it is preferable that the alumina in the thermal spray material is high purity, Na 2 O 3 contained as impurities is 0.5 mass% or less, and Fe 2 O 3 is 0%. It is preferable to use high-purity alumina of 1% by mass or less. By using high-purity alumina, the wettability between particles is improved, and densification is further promoted during thermal spraying. As a result, the adhesion between the insulating coating 6 and the base metal is increased, and the insulating performance is improved. Will also be better. Most preferably, the alumina purity is 100%, that is, pure alumina. As the purity of alumina decreases, voids tend to increase.
　更に、溶射材料は、バイヤー法等で製造したアルミナ粉末（好ましくは高純度アルミナ）とジルコニア粉末とを、１５００℃以上の電気炉であるア－ク炉にて酸素気流中で溶解し、冷却して得たインゴットを粉砕し、整粒したものを用いることが好ましい。このような製法により緻密な溶射材料が得られる。また、粉砕に際し、１０～７０μｍ、好ましくは２０～４０μｍの平均分布となるように整粒することにより、絶縁被膜６の緻密性がより向上する。 Further, as the thermal spray material, alumina powder (preferably high-purity alumina) and zirconia powder produced by the Bayer method or the like are melted in an oxygen stream in an arc furnace, which is an electric furnace at 1500 ° C. or higher, and cooled. It is preferable to use an ingot obtained by pulverization and sizing. A dense thermal spray material can be obtained by such a manufacturing method. Further, the fineness of the insulating coating 6 is further improved by sizing so as to have an average distribution of 10 to 70 μm, preferably 20 to 40 μm.
　また、溶射材料を電気炉に投入する前に、アルミナ粉末とジルコニア粉末とを混合・粉砕することが好ましい。具体的には、上記割合で配合されるジルコニア粉末と、アルミナ粉末とを、粉砕しながら混合し、得られた混合粉末を電気炉に投入して溶解し、冷却凝固してインゴットとし、その後、インゴットを粉砕して上記の粒径に分級することが好ましい。粉砕しながら混合する混合装置としては、粉砕メディアを充填した混合機、例えばビーズミルやボールミル、アトライター等を用いることができる。 Further, it is preferable to mix and pulverize the alumina powder and the zirconia powder before putting the sprayed material into the electric furnace. Specifically, the zirconia powder blended at the above ratio and the alumina powder are mixed while being pulverized, and the obtained mixed powder is dissolved in an electric furnace, cooled and solidified into an ingot, It is preferable to pulverize the ingot and classify it to the above particle size. As a mixing device for mixing while pulverizing, a mixer filled with pulverizing media, for example, a bead mill, a ball mill, an attritor or the like can be used.
　図２はこのような製造方法で作製した溶射材料（アルミナ：ジルコニア＝８：２）を撮影した電子顕微鏡写真であるが、粉砕しながら混合することにより、母材となるアルミナの塊の中に微細なジルコニア粒子が多数分散した溶射材料になる。これに対し、従来のように、ジルコニア原料粉末とアルミナ原料粉末とを、混合粉砕せず、そのまま電気炉に投入した場合には、図３に示すように、ジルコニア単体の塊とアルミナ単体の塊とが混在した溶射材料になる。 FIG. 2 is an electron micrograph of a thermal spray material (alumina: zirconia = 8: 2) produced by such a manufacturing method. By mixing while pulverizing, it is contained in an alumina lump as a base material. It becomes a thermal spray material in which many fine zirconia particles are dispersed. On the other hand, when the zirconia raw material powder and the alumina raw material powder are not mixed and pulverized and put into an electric furnace as they are, the zirconia single body mass and the alumina single body mass as shown in FIG. It becomes a thermal spray material mixed with.
　このような溶射材料を溶射すれば、粉末の流動性が改善され、粒子が壊れることがなく、大気中の酸素を溶射被膜に巻き込むことがなく溶射が可能になるので、得られる被膜中に発生する空孔が大幅に減少してより緻密になる。その結果、絶縁被膜６の絶縁性能が向上して品質的に安定する。 Spraying such a thermal spray material improves the fluidity of the powder, prevents the particles from being broken, and allows thermal spraying without entraining atmospheric oxygen in the thermal spray coating. The number of vacancies is greatly reduced and becomes denser. As a result, the insulating performance of the insulating coating 6 is improved and the quality is stabilized.
　尚、溶射方法には制限はなく、例えばプラズマ溶射法を採用することができる。また、絶縁被膜６の厚さにも制限はなく、従来と同様に１００～５００μｍ程度である。 In addition, there is no restriction | limiting in the spraying method, For example, a plasma spraying method can be employ | adopted. Further, the thickness of the insulating coating 6 is not limited, and is about 100 to 500 μm as in the conventional case.
　但し、本発明では、得られる溶射被膜の空孔率が２％以上１０％以下になるように溶射する。後述する実施例にも示すように、空孔率が２％以上１０％以下の範囲では、強度が高く、しかも強度に大きな差が無く、バラツキも小さくなる。また、空孔率５％付近がより高強度であり、好ましいといえる。 However, in the present invention, thermal spraying is performed so that the porosity of the obtained thermal spray coating is 2% or more and 10% or less. As shown in the examples described later, when the porosity is in the range of 2% or more and 10% or less, the strength is high, the strength is not greatly different, and the variation is small. Moreover, it can be said that the porosity around 5% is preferable because of higher strength.
　これに対し空孔率が２％未満または１０％を超えると、強度が低下し、更に強度のバラツキも大きくなる。一般的には空孔率が少ないほど溶射被膜が緻密で高強度になると考えられるが、空孔率が２％より小さくても膜強度が低く、しかも０％に近づくにつれて膜強度が低下していくことは、従来の知識からは考えられないことである。 On the other hand, if the porosity is less than 2% or exceeds 10%, the strength decreases and the variation in strength also increases. In general, it is considered that the smaller the porosity, the denser and higher the thermal spray coating is. However, the film strength is low even when the porosity is less than 2%, and the film strength decreases as it approaches 0%. It is impossible to think from conventional knowledge.
　空孔率は溶射条件で制御することができ、空孔率が２％以上１０％以下、好ましくは５％付近になるような溶射条件を予め予備実験により求めておき、実際の製品製造（溶射）に反映させればよい。例えば、ジルコニア－アルミナ系セラミックスからなり、１０～５０μｍに整粒した溶射材料を用いる場合、大気中にてプラズマ溶射することにより、空孔率２％以上１０％以下に制御することができる。 The porosity can be controlled by the thermal spraying conditions. The thermal spraying conditions are determined in advance by preliminary experiments so that the porosity is 2% or more and 10% or less, preferably around 5%. ). For example, when using a sprayed material made of zirconia-alumina ceramic and sized to 10 to 50 μm, the porosity can be controlled to 2% or more and 10% or less by plasma spraying in the atmosphere.
　また、溶射後に、従来と同様にして封孔処理を施してもよい。上記のように溶射による絶縁被膜６は緻密で、従来に比べて空孔が極めて少なくなっているため、この封孔処理により確実に空孔を埋めることができ、優れた絶縁性能を確保することができる。封孔剤としては、取扱性等から、アクリル樹脂、エポキシ樹脂、フッ素樹脂、フェノール樹脂、ポリエステル樹脂、あるいはこれらを複合した樹脂を含有する有機系封孔剤（エステル系、アクリル系、エポキシ系、メタクリレート系、シリコーン系、ポリエステル系）が好ましい。 Further, after thermal spraying, a sealing treatment may be performed in the same manner as in the past. As described above, the insulating coating 6 by thermal spraying is dense and has fewer pores than before, so that the pores can be reliably filled by this sealing treatment, and excellent insulation performance is ensured. Can do. As the sealing agent, from the viewpoint of handling properties, an organic sealing agent containing an acrylic resin, an epoxy resin, a fluororesin, a phenol resin, a polyester resin, or a resin in which these are combined (ester-based, acrylic-based, epoxy-based, Methacrylate type, silicone type and polyester type) are preferred.
　以下に実施例を挙げて本発明を更に説明するが、本発明はこれにより何ら制限されるものではない。 Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.
（試験１）
　呼び番号「６３１６」の単列深溝型の玉軸受（外径：１７０ｍｍ、内径：８０ｍｍ、幅：３９ｍｍ）を構成する外輪の外周面に、表１に示すようにアルミナ純度が異なり、ジルコニアを２０％含有し、残部がアルミナである溶射材料（平均粒度：２５μｍ）をプラズマ溶射して溶形成し、その後、溶射被膜に封孔処理を施して試験体を作製した。また、比較のために、溶射材としてアルミナ－１％チタニア市販溶射材を用いて試験体を作製した。また、図４に示すように、封孔処理前の試験体を切断して２０ｍｍ×１０ｍｍ×５ｍｍ（２０×１０の面に被膜）のテストピースを採取し、断面研摩後に溶射被膜の断面について下記手順にて気孔率を求めた。
（１）デジタルマイクロスコープでテストピースの断面の画像をパソコンに取り込む。
（２）取り込んだ画像を適切な閾値で２値化（黒と白の２色に変換）する。
（３）黒色部分の面積を気孔としてカウントし、「黒色部面積／測定範囲面積」から気孔率を算出する。
（４）１テストピースにつき、１２箇所でこの作業を実施し、その平均値を算出する。 (Test 1)
On the outer peripheral surface of the outer ring constituting the single row deep groove type ball bearing of the identification number “6316” (outer diameter: 170 mm, inner diameter: 80 mm, width: 39 mm), the alumina purity is different as shown in Table 1, and zirconia is 20 A thermal spray material (average particle size: 25 μm) containing alumina is formed by plasma spraying, and then the spray coating is subjected to sealing treatment to prepare a test specimen. For comparison, a test specimen was prepared using an alumina-1% titania commercial thermal spray material as the thermal spray material. Moreover, as shown in FIG. 4, the test body before sealing treatment was cut | disconnected, the test piece of 20mmx10mmx5mm (coating on the surface of 20x10) was extract | collected, and after the cross-sectional polishing, about the cross section of a sprayed coating The porosity was determined by the procedure.
(1) Using a digital microscope, capture a cross-sectional image of the test piece into a personal computer.
(2) The captured image is binarized with an appropriate threshold (converted into two colors of black and white).
(3) The area of the black part is counted as a pore, and the porosity is calculated from “black part area / measurement range area”.
(4) This work is performed at 12 locations per test piece, and the average value is calculated.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　結果を図５に示すが、気孔率が小さいほど被膜が緻密であることを示す。実施例のようにＮａ２Ｏ３が０．５質量％以下，Ｆｅ２Ｏ３が０．１質量％以下の高純度アルミナ粉末を用いることにより気孔率が２％以下と低く、アルミナの純度が低くなるほど気孔率が増大することが分かる。また、市販溶射材に比べても、実施例の溶射被膜が緻密であることが分かる。 The results are shown in FIG. 5, and the smaller the porosity, the denser the coating. By using high-purity alumina powder with Na 2 O 3 of 0.5% by mass or less and Fe 2 O 3 of 0.1% by mass or less as in the examples, the porosity is as low as 2% or less, and the purity of alumina is low It can be seen that the lower the porosity, the higher the porosity. Moreover, it turns out that the sprayed coating of an Example is dense also compared with a commercially available spraying material.
（試験２）
　試験１で用いた溶射材料を用いて外輪材料であるＳＵＪ２ブロックに溶射し、溶射被膜の密着力を測定した。密着力の測定方法を図６に示すが、溶射被膜を形成した一対のＳＵＪ２ブロック（母材）を用い、溶射被膜同士をエポキシ系接着剤で接着した後、互いに反対方向に引張り、溶射被膜が母材から剥離する引張力を測定した。 (Test 2)
The thermal spray material used in Test 1 was sprayed onto the SUJ2 block as the outer ring material, and the adhesion of the thermal spray coating was measured. The method for measuring the adhesion force is shown in FIG. 6. After using a pair of SUJ2 blocks (base materials) on which a thermal spray coating is formed, the thermal spray coatings are bonded to each other with an epoxy adhesive and then pulled in opposite directions to form a thermal spray coating. The tensile force peeled from the base material was measured.
　結果を図７に示すが、実施例のように高純度アルミナ粉末を用いることによりＳＵＪ２との密着力が高く、アルミナの純度が低くなるほど密着力が低下することが分かる。また、市販溶射材に比べても、実施例の溶射被膜は密着力が高いことが分かる。 The results are shown in FIG. 7, and it can be seen that the use of high-purity alumina powder as in the example increases the adhesion with SUJ2, and the lower the purity of alumina, the lower the adhesion. Moreover, even if it compares with a commercially available spray material, it turns out that the thermal spray coating of an Example has high adhesive force.
（試験３）
　試験１で作製した試験軸受の外輪について、絶縁抵抗値を測定した。絶縁抵抗値の測定方法を図８に示すが、試験軸受の外輪の外周に、円環状の治具を締付けボルトにて取り付け、絶縁抵抗測定機のライン線を外輪ツバ内径と、治具に接続して絶縁抵抗値を測定した。また、治具にはアース線を接続した。 (Test 3)
The insulation resistance value of the outer ring of the test bearing produced in Test 1 was measured. Fig. 8 shows how to measure the insulation resistance value. An annular jig is attached to the outer circumference of the outer ring of the test bearing with tightening bolts, and the line of the insulation resistance measuring machine is connected to the inner diameter of the outer ring collar and the jig. The insulation resistance value was measured. A ground wire was connected to the jig.
　結果を図９に示すが、実施例のように高純度アルミナ粉末を用いることにより絶縁抵抗値が高く、アルミナの純度が低くなるほど絶縁抵抗値が低下することが分かる。また、市販溶射材に比べても、実施例の溶射被膜は絶縁抵抗値が高いことが分かる。 The results are shown in FIG. 9, and it can be seen that by using high-purity alumina powder as in the examples, the insulation resistance value is high, and the lower the purity of alumina, the lower the insulation resistance value. Moreover, even if it compares with a commercially available spray material, it turns out that the thermal spray coating of an Example has a high insulation resistance value.
（試験４）
　試験１で作製した試験体について、ＪＩＳ　Ｒ　１６０７－１９９０記載のＩＦ法に準じて破壊靭性値を測定した。結果を図１０に示すが、実施例のように高純度アルミナ粉末を用いることにより破壊靭性値が高く、アルミナの純度が低くなるほど破壊靭性値が低下することが分かる。また、市販溶射材に比べても、実施例の溶射被膜は破壊靭性値が高いことが分かる。 (Test 4)
The fracture toughness value of the specimen prepared in Test 1 was measured according to the IF method described in JIS R 1607-1990. The results are shown in FIG. 10, and it can be seen that the fracture toughness value is high by using high-purity alumina powder as in the Examples, and the fracture toughness value decreases as the purity of alumina decreases. Moreover, even if it compares with a commercially available spray material, it turns out that the thermal spray coating of an Example has a high fracture toughness value.
（試験５）
　呼び番号「６３１６」の単列深溝型の玉軸受（外径：１７０ｍｍ、内径：８０ｍｍ、幅：３９ｍｍ）を構成する外輪の外周面に、表２に示すようにジルコニア含有量が異なり、残部がアルミナである溶射材料（アルミナ中のＮａ２Ｏ３：０．５質量％、Ｆｅ２Ｏ３：０．１質量％、平均粒度：２５μｍ）をプラズマ溶射し、その後、封孔処理を行い、試験体を作製した。また、比較のために、溶射材としてアルミナ－１％チタニア市販溶射材を用いて試験体を作製した。そして、試験１と同様にて溶射被膜の気孔率を測定した。 (Test 5)
As shown in Table 2, the zirconia content is different on the outer peripheral surface of the outer ring constituting the single row deep groove type ball bearing (outer diameter: 170 mm, inner diameter: 80 mm, width: 39 mm) of the identification number “6316”, and the remainder is A thermal spray material (Na 2 O 3 in alumina: 0.5 mass%, Fe 2 O 3 : 0.1 mass%, average particle size: 25 μm), which is alumina, is plasma sprayed, and then subjected to a sealing treatment and tested. The body was made. For comparison, a test specimen was prepared using an alumina-1% titania commercial thermal spray material as the thermal spray material. And the porosity of the sprayed coating was measured in the same manner as in Test 1.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　結果を図１１に示すが、実施例のようにジルコニア含有量が５～４０質量％の範囲であれば気孔率が低くなることが分かる。また、市販溶射材に比べても、実施例の溶射被膜が緻密であることが分かる。 The results are shown in FIG. 11, and it can be seen that the porosity decreases when the zirconia content is in the range of 5 to 40% by mass as in the examples. Moreover, it turns out that the sprayed coating of an Example is dense also compared with a commercially available spraying material.
（試験６）
　試験５で作製した試験体について、試験２と同様にして溶射被膜の密着力を測定した。結果を図１２に示すが、試験５の気孔率と良い相関を示しており、溶射被膜の気孔率が高まれば密着力も低下する。 (Test 6)
About the test body produced in Test 5, the adhesion of the sprayed coating was measured in the same manner as in Test 2. The results are shown in FIG. 12, which shows a good correlation with the porosity of Test 5, and the adhesion strength decreases as the porosity of the sprayed coating increases.
（試験７）
　試験５で作製した試験体について、試験３と同様にして絶縁抵抗値を測定した。結果を図１３に示すが、実施例のようにジルコニア含有量が５～４０質量％の範囲であれば絶縁抵抗値が高く、市販溶射材に比べても、実施例の溶射被膜は絶縁抵抗値が高いことが分かる。 (Test 7)
The insulation resistance value of the test body prepared in Test 5 was measured in the same manner as in Test 3. The results are shown in FIG. 13, and the insulation resistance value is high when the zirconia content is in the range of 5 to 40% by mass as in the example, and the thermal spray coating of the example has an insulation resistance value even compared to the commercially available thermal spray material. Is high.
　また、実施例１で用いた溶射原料、並びに得られた溶射被膜について、Ｘ線回折により分析した。Ｘ線回折パタ－ンを図１４に示すが、横軸が回折角度（２θ）、縦軸が回折強度を示している。これより横軸の回折角度から溶射原料はα－アルミナと単斜晶ジルコニアから成っており、プラズマ溶射することにより、溶射被膜にはγ－アルミナと立方晶ジルコニアが生成し、α－アルミナと単斜晶－ジルコニアと混在する。また、縦軸の回折強度からγ－アルミナ（楕円で囲んだ部分）の生成に伴い、α－アルミナが減少することが分かる。 Further, the thermal spray raw material used in Example 1 and the obtained thermal spray coating were analyzed by X-ray diffraction. The X-ray diffraction pattern is shown in FIG. 14, where the horizontal axis indicates the diffraction angle (2θ) and the vertical axis indicates the diffraction intensity. From the diffraction angle on the horizontal axis, the thermal spray material consists of α-alumina and monoclinic zirconia. By plasma spraying, γ-alumina and cubic zirconia are produced in the sprayed coating, and α-alumina and single crystal zirconia are formed. Mixed with oblique crystal-zirconia. It can also be seen from the diffraction intensity on the vertical axis that α-alumina decreases as γ-alumina (portion enclosed by an ellipse) is generated.
　尚、γ－アルミナとα－アルミナの比率をＸＤＲ分析にてピーク比から算出すると、分析角度:２θ=４０°－５０°にて、（γ－アルミナ／（γ－アルミナ＋α－アルミナ））×１００）の式から両者の比を求めれば、γ－アルミナとα－アルミナの比率は、γ－アルミナ：α－アルミナ＝１：９以上７：３以下であることがわかる。γ－アルミナとα－アルミナの比率が、γ－アルミナ：α‐アルミナ＝１：９未満もしくは７：３を越えると、被膜強度が低くなる。 When the ratio of γ-alumina and α-alumina is calculated from the peak ratio by XDR analysis, the analysis angle is 2θ = 40 ° -50 °, (γ-alumina / (γ-alumina + α-alumina)) × 100), the ratio of γ-alumina and α-alumina is found to be γ-alumina: α-alumina = 1: 9 to 7: 3. When the ratio of γ-alumina to α-alumina is less than γ-alumina: α-alumina = 1: 9 or exceeds 7: 3, the coating strength is lowered.
　また、実施例１で用いた溶射材料、並びに市販溶射材の外観を撮影した電子顕微鏡写真を図１５に示すが、実施例１の溶射材料の方が緻密であることがわかる。 Further, FIG. 15 shows an electron micrograph of the thermal spray material used in Example 1 and the appearance of a commercially available thermal spray material. It can be seen that the thermal spray material of Example 1 is denser.
（試験８）
　ジルコニアを２０％含有し、残部がアルミナである溶射材料を、呼び番号６３１６の単列深溝玉軸受（外径：１７０ｍｍ、内径：８０ｍｍ、幅：３９ｍｍ）を構成する外輪の外周面及び両端面に、溶射条件を変えてプラズマ溶射し（図１参照）、空孔率の異なる被膜を形成した。被膜の膜厚は、加工研磨により、何れも２００μｍ一定とした。溶射後、上記試験１と同様にして空孔率を求めた。 (Test 8)
The thermal spray material containing 20% zirconia and the balance being alumina is applied to the outer peripheral surface and both end surfaces of the outer ring constituting the single row deep groove ball bearing (outer diameter: 170 mm, inner diameter: 80 mm, width: 39 mm) of nominal number 6316. Then, plasma spraying was performed under different spraying conditions (see FIG. 1) to form films with different porosity. The film thickness of each film was fixed to 200 μm by processing and polishing. After thermal spraying, the porosity was determined in the same manner as in Test 1 above.
　次いで、被膜に、アクリル系樹脂を含有する封孔剤を塗布、乾燥して封孔処理を施して試験体とし、被膜の破壊靭性値を測定して空孔率との関係を調べた。破壊靭性値は、各試験体とも被膜の５か所について測定した。 Next, a sealing agent containing an acrylic resin was applied to the coating, dried and subjected to sealing treatment to obtain a test body, and the fracture toughness value of the coating was measured to examine the relationship with the porosity. Fracture toughness values were measured at five locations on the coating for each specimen.
　結果を図１６に示すが、一点鎖線は各空孔率における５つの測定値の中で最低値をプロットしたものであり、実線は各空孔率における５つの測定値の中で最高値をプロットしたものである。図示されるように、空孔率が２％以上１０％以下の範囲であれば、高強度であり、かつ、最低値と最高値との差が小さく、強度のバラツキの無い被膜が得られることがわかる。また、空孔率５％付近が最も破壊靭性値が大きく、好ましいことがわかる。 The results are shown in FIG. 16, where the alternate long and short dash line plots the lowest value among the five measured values at each porosity, and the solid line plots the highest value among the five measured values at each porosity. It is a thing. As shown in the drawing, when the porosity is in the range of 2% or more and 10% or less, a coating having high strength and a small difference between the minimum value and the maximum value and having no strength variation can be obtained. I understand. It can also be seen that a fracture toughness value of about 5% in the porosity is the largest and preferable.
　これに対し、空孔率が２％未満または１０％を超えると、空孔率２％以上１０％以下に比べて強度が低下しており、空孔率が０％に近づくほど、あるいは空孔率が大きくなるほど、強度の低下が大きくなっている。また、最低値と最高値との差も大きく、バラツキが大きくなっている。 On the other hand, when the porosity is less than 2% or exceeds 10%, the strength is lower than the porosity of 2% or more and 10% or less, and as the porosity approaches 0%, or the porosity The greater the rate, the greater the decrease in strength. Moreover, the difference between the minimum value and the maximum value is large, and the variation is large.
（試験９）
（実施例５）
　アルミナ粉末と、ジルコニア粉末とを、アルミナ：ジルコニア＝８：２の割合で混合した混合粉末を、ビーズミル混合機に投入し、湿式にて粉砕しながら混合した。得られたスラリー状の混合物から水分を蒸発気化して、乾燥粉末を得た。次いで、乾燥粉末を電気炉にて溶解し、冷却凝固してインゴットを得た。そして、インゴットを粉砕して１０～５０μｍに分級して溶射材料とした。 (Test 9)
(Example 5)
A mixed powder obtained by mixing alumina powder and zirconia powder in a ratio of alumina: zirconia = 8: 2 was put into a bead mill mixer and mixed while being pulverized in a wet manner. Water was evaporated from the resulting slurry mixture to obtain a dry powder. Next, the dried powder was melted in an electric furnace and cooled and solidified to obtain an ingot. The ingot was pulverized and classified to 10 to 50 μm to obtain a thermal spray material.
（比較例７）
　アルミナ粉末と、ジルコニア粉末とを、アルミナ：ジルコニア＝８：２の割合にて、混合・粉砕することなくそのまま電気炉に投入し、実施例５と同様にして溶解、冷却凝固して得たインゴットを粉砕して１０～５０μｍに分級して溶射材料とした。 (Comparative Example 7)
An ingot obtained by mixing alumina powder and zirconia powder at a ratio of alumina: zirconia = 8: 2 directly into an electric furnace without mixing and pulverizing, melting and cooling and solidifying in the same manner as in Example 5. Was pulverized and classified to 10 to 50 μm to obtain a thermal spray material.
（溶射被膜の評価）
　実施例５及び比較例７の各溶射材料を用い、プラズマ照射により鋼表面に膜厚３００μｍの溶射被膜を形成した。そして、各溶射被膜の破壊靭性値を測定して膜強度を評価した。結果を図１７に示すが、実施例５の溶射被膜は、比較例７の溶射被膜よりも約３倍近く高強度であることがわかる。 (Evaluation of thermal spray coating)
Using each thermal spray material of Example 5 and Comparative Example 7, a thermal spray coating having a film thickness of 300 μm was formed on the steel surface by plasma irradiation. And the fracture toughness value of each sprayed coating was measured to evaluate the film strength. The results are shown in FIG. 17, and it can be seen that the thermal spray coating of Example 5 is nearly three times stronger than the thermal spray coating of Comparative Example 7.
　また、各溶射被膜の破壊電圧値を測定して膜特性（絶縁性）を評価した。結果を図１８に示すが、実施例５の溶射被膜は、比較例７の溶射被膜よりも約２倍強も高性能であることがわかる。 Also, the breakdown voltage value of each sprayed coating was measured to evaluate the film characteristics (insulating properties). The results are shown in FIG. 18, and it can be seen that the thermal spray coating of Example 5 is about twice as high as the thermal spray coating of Comparative Example 7.
　更に、各溶射被膜の断面の電子顕微鏡写真で撮影した。図１９に示すが、比較例７の溶射被膜では粗大なジルコニアが数多く点在しているのに対し、実施例５の溶射被膜では粗大なジルコニアが見られず、均一な組織であることがわかる。 Furthermore, an electron micrograph of the cross section of each sprayed coating was taken. As shown in FIG. 19, the sprayed coating of Comparative Example 7 is dotted with many coarse zirconia, whereas the sprayed coating of Example 5 shows no uniform zirconia and a uniform structure. .
　このように、原料粉末を粉砕しながら混合することにより、膜強度や膜特性がより良好になる。 Thus, by mixing the raw material powder while pulverizing, the film strength and film characteristics become better.
　尚、上記した本実施形態では軸受の外輪だけに絶縁被膜を形成した例を挙げたが、内輪または転動体にも同様の絶縁被膜を形成してもよく、外輪、内輪及び転動体の全てに絶縁被膜を形成してもよい。 In the above-described embodiment, an example in which an insulating coating is formed only on the outer ring of the bearing has been described. However, a similar insulating coating may be formed on the inner ring or the rolling element, and all of the outer ring, the inner ring and the rolling element may be formed. An insulating film may be formed.
　本発明を詳細にまた特定の実施態様を参照して説明したが、本発明の精神と範囲を逸脱することなく様々な変更や修正を加えることができることは当業者にとって明らかである。
　本出願は、２０１５年４月１日出願の日本特許出願（特願２０１５－０７５２００）に基づくものであり、その内容はここに参照として取り込まれる。 Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application filed on April 1, 2015 (Japanese Patent Application No. 2015-075200), the contents of which are incorporated herein by reference.
　本発明の電食防止用絶縁転がり軸受は、絶縁被膜の膜強度や絶縁特性に優れるため、電動モータや発電機等の回転軸を支承する軸受として有用である。 Since the insulating rolling bearing for preventing electric corrosion of the present invention is excellent in film strength and insulating properties of the insulating coating, it is useful as a bearing for supporting a rotating shaft of an electric motor, a generator or the like.
１　内輪
２　内輪軌道
３　外輪
４　外輪軌道
５　転動体
６　絶縁被膜
７　外輪の外周面 DESCRIPTION OF SYMBOLS 1 Inner ring 2 Inner ring track 3 Outer ring 4 Outer ring track 5 Rolling element 6 Insulation coating 7 Outer ring outer peripheral surface

Claims (8)

  1. 　内周面に外輪軌道を形成した金属製の外輪と、この外輪の内側に配置され、外周面に内輪軌道を形成した金属製の内輪と、これら外輪軌道と内輪軌道との間に転動自在に設けられた、それぞれが金属製である複数個の転動体とを備え、前記外輪、前記内輪及び前記転動体の少なくとも１つに絶縁被膜が形成された電食防止用絶縁転がり軸受において、
    　前記絶縁被膜が、アルミナとジルコニアとを主成分とし、かつ、ジルコニアがアルミナとジルコニアとの総量に対し５質量％以上４０質量％以下であり、前記アルミナはα－アルミナとγ－アルミナを含有し、前記ジルコニアは単斜晶ジルコニアと立方晶ジルコニアの少なくとも一方を含有することを特徴とする電食防止用絶縁転がり軸受。     A metal outer ring having an outer ring raceway formed on the inner peripheral surface, a metal inner ring disposed inside the outer ring and having an inner ring raceway formed on the outer peripheral surface, and freely rollable between the outer ring raceway and the inner ring raceway. A plurality of rolling elements each made of metal, and at least one of the outer ring, the inner ring and the rolling elements, an insulating corrosion bearing for preventing electric corrosion in which an insulating film is formed,
    The insulating coating contains alumina and zirconia as main components, and zirconia is 5% by mass or more and 40% by mass or less based on the total amount of alumina and zirconia, and the alumina contains α-alumina and γ-alumina. The zirconia contains at least one of monoclinic zirconia and cubic zirconia.
  2. 　γ－アルミナとα－アルミナとの比率が、Ｘ線回折ピーク比で、γ－アルミナ：α－アルミナ＝１：９以上７：３以下であることを特徴とする請求項１記載の電食防止用絶縁転がり軸受。 2. The electrolytic corrosion prevention according to claim 1, wherein the ratio of γ-alumina to α-alumina is γ-alumina: α-alumina = 1: 9 or more and 7: 3 or less as an X-ray diffraction peak ratio. Insulated rolling bearing.
  3. 　前記絶縁被膜の空孔率が２％以上１０％以下であることを特徴とする請求項１または２記載の電食防止用絶縁転がり軸受。 The insulating rolling bearing for preventing electrolytic corrosion according to claim 1 or 2, wherein a porosity of the insulating coating is 2% or more and 10% or less.
  4. 　前記絶縁層の空孔が、合成樹脂で封孔されていることを特徴とする請求項１～３の何れか１項に記載の電食防止用絶縁転がり軸受。 The insulated rolling bearing for preventing electrolytic corrosion according to any one of claims 1 to 3, wherein the holes in the insulating layer are sealed with a synthetic resin.
  5. 　内周面に外輪軌道を形成した金属製の外輪と、この外輪の内側に配置され、外周面に内輪軌道を形成した金属製の内輪と、これら外輪軌道と内輪軌道との間に転動自在に設けられた、それぞれが金属製である複数個の転動体とを備え、前記外輪、前記内輪及び前記転動体の少なくとも１つに絶縁被膜が形成された電食防止用絶縁転がり軸受を製造する方法において、
    　アルミナ粉末とジルコニア粉末とを溶射材の原料粉末とし、かつ、ジルコニアの含有量が前記溶射材全量の５質量％以上４０質量％以下である溶射材料を溶射して溶射被膜を形成することを特徴とする電食防止用絶縁転がり軸受の製造方法。     A metal outer ring having an outer ring raceway formed on the inner peripheral surface, a metal inner ring disposed inside the outer ring and having an inner ring raceway formed on the outer peripheral surface, and freely rollable between the outer ring raceway and the inner ring raceway. And a plurality of rolling elements each made of metal, and an insulating rolling bearing for preventing electric corrosion in which an insulating film is formed on at least one of the outer ring, the inner ring, and the rolling elements. In the method
    Alumina powder and zirconia powder are used as a raw material powder of a thermal spray material, and a thermal spray coating is formed by spraying a thermal spray material having a zirconia content of 5 mass% to 40 mass% of the total amount of the thermal spray material. A method of manufacturing an insulating rolling bearing for preventing electrical corrosion.
  6. 　前記溶射被膜を形成した後、合成樹脂を含有する封孔剤により封孔処理することを特徴とする請求項５記載の電食防止用絶縁転がり軸受の製造方法。 6. The method of manufacturing an insulating rolling bearing for preventing electrolytic corrosion according to claim 5, wherein after the thermal spray coating is formed, sealing treatment is performed with a sealing agent containing a synthetic resin.
  7. 　前記アルミナ粉末が、Ｎａ２Ｏ３：０．５質量％以下、Ｆｅ２Ｏ３：０．１質量％以下の高純度アルミナであることを特徴とする請求項５または６記載の電食防止用絶縁転がり軸受の製造方法。 The alumina powder, Na 2 O 3: 0.5 wt% or less, Fe 2 O 3: claim 5 or 6 for preventing electrolytic corrosion of wherein a is 0.1 wt% or less of a high-purity alumina Insulated rolling bearing manufacturing method.
  8. 　前記アルミナ粉末とジルコニア粉末とを粉砕しながら混合して混合粉末とし、前記混合粉末を１５００℃以上の電気炉にて酸素気流中で溶解し、冷却して得たインゴットを粉砕し、１０～７０μｍに整粒して得た溶射材料を溶射することを特徴とする請求項５～７の何れか１項に記載の電食防止用絶縁転がり軸受の製造方法。 The alumina powder and the zirconia powder are mixed while being pulverized to form a mixed powder, and the mixed powder is dissolved in an oxygen stream in an electric furnace at 1500 ° C. or higher, cooled, and the ingot obtained by pulverization is pulverized to 10 to 70 μm. The method for producing an insulating rolling bearing for preventing electrolytic corrosion according to any one of claims 5 to 7, wherein a thermal spray material obtained by adjusting the particle size is sprayed.
PCT/JP2015/076506 2015-04-01 2015-09-17 Roller bearing having insulation for prevention of electrolytic corrosion, and method for manufacturing same WO2016157572A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112553558A (en) * 2020-11-20 2021-03-26 中机凯博表面技术江苏有限公司 Preparation method of bearing surface insulating coating
CN115142005A (en) * 2021-04-15 2022-10-04 浙江福腾宝家居用品有限公司 Cooking utensil and preparation method thereof

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JP2006291350A (en) * 2005-04-07 2006-10-26 Sulzer Metco Ag Material and method for thermal coating, surface layer, and compressor provided with surface layer made from the material
JP2007198519A (en) * 2006-01-27 2007-08-09 Nsk Ltd Insulating roller bearing for preventing electric corrosion
JP2008082413A (en) * 2006-09-27 2008-04-10 Ntn Corp Insulated rolling bearing
JP2014190393A (en) * 2013-03-27 2014-10-06 Nsk Ltd Rolling body

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006291350A (en) * 2005-04-07 2006-10-26 Sulzer Metco Ag Material and method for thermal coating, surface layer, and compressor provided with surface layer made from the material
JP2007198519A (en) * 2006-01-27 2007-08-09 Nsk Ltd Insulating roller bearing for preventing electric corrosion
JP2008082413A (en) * 2006-09-27 2008-04-10 Ntn Corp Insulated rolling bearing
JP2014190393A (en) * 2013-03-27 2014-10-06 Nsk Ltd Rolling body

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112553558A (en) * 2020-11-20 2021-03-26 中机凯博表面技术江苏有限公司 Preparation method of bearing surface insulating coating
CN115142005A (en) * 2021-04-15 2022-10-04 浙江福腾宝家居用品有限公司 Cooking utensil and preparation method thereof

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