WO2024034529A1 - Resin insulated rolling bearing - Google Patents

Resin insulated rolling bearing Download PDF

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Publication number
WO2024034529A1
WO2024034529A1 PCT/JP2023/028523 JP2023028523W WO2024034529A1 WO 2024034529 A1 WO2024034529 A1 WO 2024034529A1 JP 2023028523 W JP2023028523 W JP 2023028523W WO 2024034529 A1 WO2024034529 A1 WO 2024034529A1
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WO
WIPO (PCT)
Prior art keywords
bearing
outer ring
resin
rolling bearing
ring
Prior art date
Application number
PCT/JP2023/028523
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French (fr)
Japanese (ja)
Inventor
隼人 川口
朋久 魚住
泰人 藤掛
慎太郎 田中
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Ntn株式会社
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Publication of WO2024034529A1 publication Critical patent/WO2024034529A1/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
    • 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
    • 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
    • F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
    • F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
    • F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
    • F16C35/07—Fixing them on the shaft or housing with interposition of an element

Definitions

  • This invention relates to a resin insulated rolling bearing.
  • Electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles) are known as vehicles that use an electric motor as a driving force for driving. These electric vehicles use an inverter that converts the DC power of the battery into AC power in order to supply AC power to the electric motor. frequency is set high.
  • the electric potential difference generated between the main shaft of the electric motor and the motor housing makes it easier for current to flow through the rolling bearing that supports the main shaft of the electric motor.
  • sparks are generated between the raceway surface of the rolling bearing and the rolling elements, and the sparks may cause gradual damage to the raceway surface (electrolytic corrosion).
  • insulated rolling bearings are generally used for the rolling bearings that support the main shaft of the electric motor and the shaft of the reducer of electric vehicles.
  • An insulated rolling bearing consists of an outer ring, an inner ring disposed coaxially inside the outer ring in the radial direction, a plurality of rolling elements installed between the outer ring and the inner ring, and an outer ring provided on the outer circumference of the outer ring and on the axial end faces on both sides of the outer ring.
  • Those with an insulating layer and an insulating layer are widely used.
  • the applicant of the present application has already proposed an insulated rolling bearing using a resin film as an insulating layer (Patent Document 1).
  • Patent Document 1 when a resin film is used as an insulating layer of an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, the specifications of the resin film (film thickness, It is unclear how to set the capacitance, electrical resistance, etc.), and for this reason, in the past, it has been preferable to use insulated rolling bearings that use a sufficiently thick resin film with excellent electrolytic corrosion resistance. It was common.
  • the inventors of the present application have discovered that the specifications are excessive compared to the specifications necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric motor of an electric vehicle. We focused on the possibility that unnecessary costs were being incurred.
  • the inventors when using a resin-insulated rolling bearing as an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, the inventors have developed a resin coating that is necessary and sufficient to ensure the electrical corrosion resistance of the resin-insulated rolling bearing. We considered how to set the specifications.
  • the electrical corrosion resistance of resin-insulated rolling bearings is determined by the current density flowing through the contact area between the raceway surface and the rolling elements due to the AC voltage applied to the bearing, and the total passage of the rolling elements at a fixed position on the raceway surface. They discovered that it is possible to evaluate the electrolytic corrosion resistance of resin-insulated rolling bearings that support the main shaft of an electric vehicle's electric motor based on the relationship between the number of cycles and the integrated value of the AC voltage frequency. We have discovered the conditions that must be met to ensure a sufficient resin film.
  • the problem to be solved by this invention is to provide a resin insulated rolling bearing with specifications necessary and sufficient to ensure the electrical corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric motor of an electric vehicle.
  • the present invention provides a resin insulated rolling bearing having the following configuration.
  • a resin insulated rolling bearing comprising an insulating resin film provided on the outer circumference of the outer ring and the axial end face of the outer ring, or the inner circumference of the inner ring and the axial end face of the inner ring,
  • the diameter of the rolling element is Dw (mm)
  • the number of the rolling elements is z (pieces)
  • the pitch diameter of the rolling element is dp (mm)
  • the distance between the inner circumference of the inner ring and the outer circumference of the outer ring is
  • the capacitance including the resin film is C (F)
  • the electrical resistance including the resin film between the inner periphery of the inner ring and the outer periphery of the outer ring is R ( ⁇ )
  • the general usage conditions of an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle that is, the frequency of the AC voltage applied to the bearing is 20kHz or less, the voltage is 1V or less, and the rotation speed of the inner ring is
  • the frequency of the AC voltage applied to the bearing is 20kHz or less
  • the voltage is 1V or less
  • the rotation speed of the inner ring is
  • the dynamic equivalent radial load acting on the bearing is below 30000 min -1 and the dynamic equivalent radial load acting on the bearing is below the basic rated load
  • the rotational speed corresponds to the basic rated life or less, and the specifications of the resin coating are necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric motor of the electric vehicle.
  • the resin film is provided on the outer periphery of the outer ring and on the axial end surface of the outer ring,
  • the thickness of the resin film is thin, the change in the thickness of the resin film due to temperature changes is small, and when the resin film expands at high temperatures, excessive interference between the outer ring and the motor housing may occur.
  • the resin insulated rolling bearing of the present invention satisfies the general usage conditions of an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, namely, the frequency of the AC voltage applied to the bearing is 20 kHz or less, the voltage is 1 V or less, and the inner ring
  • a sectional view showing a resin insulated rolling bearing according to an embodiment of the invention Diagram showing the results of electrolytic corrosion test Diagram schematically showing the electrolytic corrosion test circuit for an insulating film simulated bearing Diagram schematically showing the electrolytic corrosion test circuit for standard bearings
  • FIG. 1 shows a resin insulated rolling bearing 1 according to an embodiment of the invention.
  • the resin insulated rolling bearing 1 includes an outer ring 2, an inner ring 3 disposed coaxially inside the outer ring 2 in the radial direction, a plurality of rolling elements 4 incorporated between the outer ring 2 and the inner ring 3, and the plurality of rolling elements 4. It has an insulating resin film 8 provided on the outer periphery 6 of the outer ring 2 and the end surfaces 7 on both sides in the axial direction.
  • an outer ring raceway surface 9 with which the rolling elements 4 roll and come into contact, and outer ring shoulders 10 located on both sides of the outer ring raceway surface 9 in the axial direction are formed on the inner periphery of the outer ring 2.
  • an inner ring raceway surface 11 with which the rolling elements 4 come into rolling contact is formed on the outer periphery of the inner ring 3 .
  • the rolling elements 4 are balls here.
  • the outer ring raceway surface 9 and the inner ring raceway surface 11 are both inner surfaces of grooves having an arcuate cross section.
  • the outer ring 2, the inner ring 3, and the rolling elements 4 are all made of metal (for example, bearing steel).
  • the outer circumference 6 of the outer ring 2 is a cylindrical surface whose outer diameter does not change along the axial direction and is constant. End surfaces 7 on both sides of the outer ring 2 in the axial direction are planes perpendicular to the axial direction.
  • a chamfered portion 13 having an arcuate cross section is formed between the outer periphery 6 of the outer ring 2 and the end surfaces 7 on both sides of the outer ring 2 in the axial direction.
  • the resin film 8 includes an outer circumferential covering part 8a that covers the outer periphery 6 of the outer ring 2, a chamfer covering part 8b that covers the chamfered part 13 of the outer ring 2, and an end face covering part 8c that covers the axial end faces 7 on both sides of the outer ring 2. It is made up of.
  • the thickness of the outer peripheral covering portion 8a is set to 50 ⁇ m or less.
  • the film thicknesses of the chamfered covering portion 8b and the end face covering portion 8c are also set to 50 ⁇ m or less.
  • the thickness of the outer periphery coating portion 8a and the thickness of the end surface coating portion 8c are the same.
  • the resin film 8 can generally have a withstand voltage of 0.01 kV/ ⁇ m or more when a resin based on epoxy resin or a resin based on polyamideimide resin is used.
  • FIG. 2 shows the results of an electrolytic corrosion test conducted by the inventors of the present application.
  • the test conditions for this electrolytic corrosion test are as follows.
  • Test method As shown in Fig. 3, a capacitor 33 with a capacitance of 6.5 nF and an electric resistance of 200 ⁇ are used in a test circuit that applies an AC voltage between the inner ring and outer ring of a standard bearing 32 using an AC power supply 31.
  • a resin insulated rolling bearing 1 using a resin film 8 of polyamideimide resin having a film thickness of about 25 ⁇ m as an insulating layer was simulated by incorporating a resistor 34 having a thickness of about 25 ⁇ m (insulating film simulated bearing). Furthermore, a similar test was conducted on the standard bearing 32 using the test circuit shown in FIG. 4 (standard bearing). Then, the standard bearing is operated in the testing device 35, and the operation is stopped when the bearing vibration becomes twice the initial vibration due to electrolytic corrosion, and the bearing vibration becomes 10 times the initial vibration based on the vibration data during the test. The time it took was calculated (Figure 2). Note that the plots of 5V for the insulation coating simulated bearing and 20V for the standard bearing are estimated from the test time ratio of the standard bearing/insulation coating simulation bearing at 10V.
  • the area to the right and above the line graph of the "insulation film simulated bearing” is an area where the electrical corrosion resistance of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of the electric vehicle cannot be ensured.
  • OK region 1 and OK region 2 are regions where the specifications are excessive compared to the specifications necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of the electric vehicle.
  • the OK region 1 is a region where the frequency exceeds 1.6 ⁇ 10 10 (times ⁇ Hz) and falls below 1.3 ⁇ 10 12 (times ⁇ Hz) on the horizontal axis. Further, it is a region of 9.8 ⁇ 10 ⁇ 6 (A/mm 2 ) or more on the vertical axis.
  • OK region 2 is a region where the frequency exceeds 1.6 ⁇ 10 10 (times ⁇ Hz) on the horizontal axis and falls below 9.8 ⁇ 10 ⁇ 6 (A/mm 2 ) on the vertical axis.
  • the integrated value (horizontal axis), which is the total number of passes of the rolling elements 4 at a fixed position on the raceway surface multiplied by the frequency of the AC voltage, is the frequency of the AC voltage applied to the bearing 1, f (Hz), and the frequency of the AC voltage applied to the bearing 1.
  • the rotation speed of bearing 3 is Ni (min -1 )
  • the diameter of rolling element 4 is Dw (mm)
  • the number of rolling elements 4 is z (pieces)
  • the pitch diameter of rolling element 4 is dp (mm)
  • the diameter of bearing 1 is
  • the operating time is h (min)
  • the current density (vertical axis) flowing through the contact area between the raceway surface and the rolling elements 4 due to the AC voltage applied to the bearing 1 is determined by the capacitance of the bearing 1 (specifically, the inner circumference of the inner ring 3 and the outer ring C (F) is the electrical resistance of the bearing 1 (specifically, the resin between the inner circumference of the inner ring 3 and the outer circumference 6 of the outer ring 2).
  • the electrical resistance (including the coating 8) is R ( ⁇ ), the frequency of the AC voltage applied to the bearing 1 is f (Hz), and the area of the contact part (contact ellipse) between the raceway surface and the rolling elements 4 is A ( mm 2 ) and the AC voltage applied to the bearing 1 is V 0 (V), it can be determined by the following equation.
  • the frequency f (Hz) of the AC voltage applied to the bearing 1 is 20 kHz or less
  • the rotation speed Ni of the inner ring 3 is 1000 to 30000 min -1.
  • the basic The area A of the contact ellipse when a dynamic load rating is applied is 25 mm 2
  • the AC voltage V 0 (V) applied to the bearing 1 is 1V or less.
  • the pair of X and Y defined by the following equations (1) and (2) satisfies 1.6 ⁇ X ⁇ 130 and Y ⁇ 2.45 ⁇ 10 ⁇ 4 (that is, 1.6 ⁇ X and 0 ⁇ Y ⁇ 2.45 ⁇ 10 ⁇ 4 (that is, within OK region 2 of FIG. 2) )
  • the specifications of the resin film 8 are set as follows.
  • the resin insulated rolling bearing 1 of the above embodiment meets the general usage conditions of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of an electric vehicle, that is, the frequency of the AC voltage applied to the bearing 1.
  • the voltage is 20 kHz or less
  • the voltage is 1 V or less
  • the rotational speed of the inner ring 3 is 30,000 min -1 or less
  • the dynamic equivalent radial load acting on the bearing 1 is less than the basic rated load
  • the bearing vibration will be 10 times the initial vibration due to electrolytic corrosion.
  • the total number of revolutions of the bearing 1 until the size of It is necessary and sufficient to ensure the electrolytic corrosion resistance of the supported insulated rolling bearing 1, and is low cost.
  • the thickness of the resin film 8 is set to 50 ⁇ m or less, so the change in the thickness of the resin film 8 due to temperature changes is small, and the resin insulated rolling bearing 1 in the high temperature state Prevents the expansion of the film 8 from creating an excessive interference between the outer ring 2 and the motor housing 21, and on the other hand, prevents the creation of an excessive gap between the outer ring 2 and the motor housing 21 when the temperature is low. can do. Therefore, when used as an insulated rolling bearing that supports the main shaft 20 of an electric motor of an electric vehicle, the fitting gap between the outer ring 2 and the motor housing 21 can be appropriately set.
  • the resin insulated rolling bearing 1 which has the resin film 8 on the outer periphery 6 of the outer ring 2 and the axial end faces 7 on both sides of the outer ring 2 has been described as an example.
  • the same can be applied to a resin insulated rolling bearing having a resin film 8 only on the directional end face 7, and also a resin insulated rolling bearing having a resin film 8 on the inner periphery of the inner ring 3 and the axial end face on both sides or one side of the inner ring 3.
  • rolling bearings the same applies to rolling bearings.
  • the resin insulated rolling bearing 1 in which the inner circumference of the outer ring 2 is not provided with a resin film has been described as an example, but the present invention adds a resin film 8 to the inner circumference of the outer ring 2.
  • the resin film 8 may be additionally provided on the outer periphery of the inner ring 3.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rolling Contact Bearings (AREA)
  • Mounting Of Bearings Or Others (AREA)

Abstract

When a diameter of a rolling element (4) is Dw (mm), the number of rolling elements (4) is z (pieces), a pitch circle diameter of the rolling elements (4) is dp (mm), capacitance is C (F), and electrical resistance is R (Ω), a pair of X and Y defined by the following formulas (1), (2) satisfy 1.6 < X < 130, and Y ≥ 2.45×10-4, or 1.6 < X, and 0 < Y < 2.45×10-4.

Description

樹脂絶縁転がり軸受Resin insulated rolling bearing
　この発明は、樹脂絶縁転がり軸受に関する。 This invention relates to a resin insulated rolling bearing.
　走行用の原動機として電動モータを使用する自動車として、ＥＶ（バッテリー式電気自動車）やＨＥＶ（ハイブリッド電気自動車）などの電気自動車が知られている。これらの電気自動車では、電動モータに交流電力を供給するために、バッテリの直流電力を交流電力に変換するインバータが使用され、電動モータの高効率化を図るために、電動モータに供給する交流電力の周波数が高く設定される。 Electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles) are known as vehicles that use an electric motor as a driving force for driving. These electric vehicles use an inverter that converts the DC power of the battery into AC power in order to supply AC power to the electric motor. frequency is set high.
　ここで、電動モータに供給される交流電力の周波数が高くなると、電動モータの主軸とモータハウジングとの間に生じる電位差によって、電動モータの主軸を支持する転がり軸受に電流が流れやすくなる。そして、転がり軸受に電流が流れると、転がり軸受の軌道面と転動体の間にスパークが発生し、そのスパークによって軌道面の損傷が次第に進行する現象（電食）が生じることがある。 Here, when the frequency of the AC power supplied to the electric motor increases, the electric potential difference generated between the main shaft of the electric motor and the motor housing makes it easier for current to flow through the rolling bearing that supports the main shaft of the electric motor. When current flows through the rolling bearing, sparks are generated between the raceway surface of the rolling bearing and the rolling elements, and the sparks may cause gradual damage to the raceway surface (electrolytic corrosion).
　そこで、電食を防止するため、一般に、電気自動車の電動モータの主軸や減速機の軸を支持する転がり軸受には、絶縁転がり軸受が使用されることがある。絶縁転がり軸受は、外輪と、外輪の径方向内側に同軸に配置される内輪と、外輪と内輪の間に組み込まれる複数の転動体と、外輪の外周および外輪の両側の軸方向端面に設けられた絶縁層とを有するものが広く使用される。そして、そのような絶縁転がり軸受として、本願の出願人は、樹脂皮膜を絶縁層として用いた絶縁転がり軸受を既に提案している（特許文献１）。 Therefore, in order to prevent electrolytic corrosion, insulated rolling bearings are generally used for the rolling bearings that support the main shaft of the electric motor and the shaft of the reducer of electric vehicles. An insulated rolling bearing consists of an outer ring, an inner ring disposed coaxially inside the outer ring in the radial direction, a plurality of rolling elements installed between the outer ring and the inner ring, and an outer ring provided on the outer circumference of the outer ring and on the axial end faces on both sides of the outer ring. Those with an insulating layer and an insulating layer are widely used. As such an insulated rolling bearing, the applicant of the present application has already proposed an insulated rolling bearing using a resin film as an insulating layer (Patent Document 1).
特開２０２２－０４２１６２号公報JP2022-042162A
　特許文献１のように、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の絶縁層として樹脂皮膜を用いる場合、絶縁転がり軸受の耐電食性を確保するには、樹脂皮膜の仕様（膜厚、静電容量、電気抵抗など）をどのように設定すればよいかが不明であり、そのため従来においては、耐電食性に優れた膜厚の十分に大きい樹脂皮膜を用いた絶縁転がり軸受を採用するのが一般的であった。 As in Patent Document 1, when a resin film is used as an insulating layer of an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, the specifications of the resin film (film thickness, It is unclear how to set the capacitance, electrical resistance, etc.), and for this reason, in the past, it has been preferable to use insulated rolling bearings that use a sufficiently thick resin film with excellent electrolytic corrosion resistance. It was common.
　この従来の絶縁転がり軸受の樹脂皮膜に関し、本願の発明者らは、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の耐電食性を確保するのに必要十分な仕様に対して過剰な仕様となっており、無用のコストが発生している可能性に着目した。 Regarding the resin coating of the conventional insulated rolling bearing, the inventors of the present application have discovered that the specifications are excessive compared to the specifications necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric motor of an electric vehicle. We focused on the possibility that unnecessary costs were being incurred.
　そこで、発明者らは、電気自動車の電動モータの主軸を支持する絶縁転がり軸受として樹脂絶縁転がり軸受を使用する場合に、その樹脂絶縁転がり軸受の耐電食性を確保するのに必要十分な樹脂皮膜の仕様をどう設定すればよいかを検討した。その検討の結果、樹脂絶縁転がり軸受の耐電食性は、軸受に印加される交流電圧により軌道面と転動体の間の接触部を流れる電流密度と、軌道面の定位置での転動体の総通過回数に交流電圧の周波数を積算した積算値との関係に基づいて評価することができることを発見し、その関係に基づいて、電気自動車の電動モータの主軸を支持する樹脂絶縁転がり軸受の耐電食性を確保するのに必要十分な樹脂皮膜の満たすべき条件を見出した。 Therefore, when using a resin-insulated rolling bearing as an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, the inventors have developed a resin coating that is necessary and sufficient to ensure the electrical corrosion resistance of the resin-insulated rolling bearing. We considered how to set the specifications. As a result of the study, the electrical corrosion resistance of resin-insulated rolling bearings is determined by the current density flowing through the contact area between the raceway surface and the rolling elements due to the AC voltage applied to the bearing, and the total passage of the rolling elements at a fixed position on the raceway surface. They discovered that it is possible to evaluate the electrolytic corrosion resistance of resin-insulated rolling bearings that support the main shaft of an electric vehicle's electric motor based on the relationship between the number of cycles and the integrated value of the AC voltage frequency. We have discovered the conditions that must be met to ensure a sufficient resin film.
　この発明が解決しようとする課題は、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の耐電食性を確保するのに必要十分な仕様の樹脂絶縁転がり軸受を提供することである。 The problem to be solved by this invention is to provide a resin insulated rolling bearing with specifications necessary and sufficient to ensure the electrical corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric motor of an electric vehicle.
　上記の課題を解決するため、この発明では、以下の構成の樹脂絶縁転がり軸受を提供する。
［構成１］
　外輪と、
　前記外輪の径方向内側に同軸に配置される内輪と、
　前記外輪と前記内輪の間に組み込まれる複数の転動体と、
　前記外輪の外周および前記外輪の軸方向端面、または前記内輪の内周および前記内輪の軸方向端面に設けられた絶縁性の樹脂皮膜と、を有する樹脂絶縁転がり軸受において、
　前記転動体の直径をＤｗ（ｍｍ）、前記転動体の個数をｚ（個）、前記転動体のピッチ円径をｄｐ（ｍｍ）、前記内輪の内周と前記外輪の外周との間の前記樹脂皮膜を含めた静電容量をＣ（Ｆ）、前記内輪の内周と前記外輪の外周との間の前記樹脂皮膜を含めた電気抵抗をＲ（Ω）としたときに、次式（１）（２）で定義されるＸ，Ｙの組が、１．６＜Ｘ＜１３０、かつ、Ｙ≧２．４５×１０－４を満たすか、または、１．６＜Ｘ、かつ、０＜Ｙ＜２．４５×１０－４を満たすことを特徴とする樹脂絶縁転がり軸受。
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
 In order to solve the above problems, the present invention provides a resin insulated rolling bearing having the following configuration.
[Configuration 1]
outer ring and
an inner ring disposed coaxially inside the outer ring in the radial direction;
a plurality of rolling elements incorporated between the outer ring and the inner ring;
A resin insulated rolling bearing comprising an insulating resin film provided on the outer circumference of the outer ring and the axial end face of the outer ring, or the inner circumference of the inner ring and the axial end face of the inner ring,
The diameter of the rolling element is Dw (mm), the number of the rolling elements is z (pieces), the pitch diameter of the rolling element is dp (mm), and the distance between the inner circumference of the inner ring and the outer circumference of the outer ring is When the capacitance including the resin film is C (F) and the electrical resistance including the resin film between the inner periphery of the inner ring and the outer periphery of the outer ring is R (Ω), the following formula (1 ) The pair of X and Y defined in (2) satisfies 1.6<X<130 and Y≧2.45×10 −4 , or 1.6<X and 0< A resin insulated rolling bearing characterized by satisfying Y<2.45×10 −4 .
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
　このようにすると、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の一般的な使用条件、すなわち、軸受に印加される交流電圧の周波数が２０ｋＨｚ以下、電圧が１Ｖ以下、内輪の回転数が３００００ｍｉｎ－１以下、軸受に作用する動等価ラジアル荷重が基本定格荷重以下の使用条件において、電食で軸受振動が初期振動の１０倍の大きさになるまでの軸受の総回転数が、軸受の基本定格寿命に対応する回転数かそれ以下となり、樹脂皮膜の仕様が、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の耐電食性を確保するのに必要十分なものとなる。 In this way, the general usage conditions of an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, that is, the frequency of the AC voltage applied to the bearing is 20kHz or less, the voltage is 1V or less, and the rotation speed of the inner ring is Under operating conditions where the dynamic equivalent radial load acting on the bearing is below 30000 min -1 and the dynamic equivalent radial load acting on the bearing is below the basic rated load, the total number of revolutions of the bearing until bearing vibration becomes 10 times the initial vibration due to electrolytic corrosion is The rotational speed corresponds to the basic rated life or less, and the specifications of the resin coating are necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric motor of the electric vehicle.
［構成２］
　前記樹脂皮膜は、前記外輪の外周および前記外輪の軸方向端面に設けられ、
　前記樹脂皮膜の膜厚が５０μｍ以下に設定されている構成１に記載の樹脂絶縁転がり軸受。 [Configuration 2]
The resin film is provided on the outer periphery of the outer ring and on the axial end surface of the outer ring,
The resin insulated rolling bearing according to configuration 1, wherein the resin film has a thickness of 50 μm or less.
　このようにすると、樹脂皮膜の膜厚が薄いので、温度変化による樹脂皮膜の膜厚の変化が小さく、高温状態のときに、樹脂皮膜の膨張により、外輪とモータハウジングの間に過大な締め代が生じたり、一方、低温状態のときに、外輪とモータハウジングの間に過大な隙間が生じたりするのを防止することができる。そのため、電気自動車の電動モータの主軸を支持する絶縁転がり軸受として使用するときに、外輪とモータハウジングの間のはめあい隙間を適切に設定することができる。 In this way, since the thickness of the resin film is thin, the change in the thickness of the resin film due to temperature changes is small, and when the resin film expands at high temperatures, excessive interference between the outer ring and the motor housing may occur. On the other hand, it is possible to prevent the formation of an excessive gap between the outer ring and the motor housing when the temperature is low. Therefore, when used as an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, the fitting gap between the outer ring and the motor housing can be appropriately set.
　この発明の樹脂絶縁転がり軸受は、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の一般的な使用条件、すなわち、軸受に印加される交流電圧の周波数が２０ｋＨｚ以下、電圧が１Ｖ以下、内輪の回転数が３００００ｍｉｎ－１以下、軸受に作用する動等価ラジアル荷重が基本定格荷重以下の使用条件において、電食で軸受振動が初期振動の１０倍の大きさになるまでの軸受の総回転数が、軸受の基本定格寿命に対応する回転数かそれ以下となっており、樹脂皮膜の仕様が、電気自動車の電動モータの主軸を支持する絶縁転がり軸受の耐電食性を確保するのに必要十分であり、低コストである。 The resin insulated rolling bearing of the present invention satisfies the general usage conditions of an insulated rolling bearing that supports the main shaft of an electric motor of an electric vehicle, namely, the frequency of the AC voltage applied to the bearing is 20 kHz or less, the voltage is 1 V or less, and the inner ring The total number of rotations of the bearing until bearing vibration becomes 10 times the initial vibration due to electrolytic corrosion under operating conditions where the rotation speed of However, the rotation speed is at or below the basic rated life of the bearing, and the specifications of the resin coating are necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing that supports the main shaft of the electric vehicle's electric motor. Yes, and low cost.
この発明の実施形態にかかる樹脂絶縁転がり軸受を示す断面図A sectional view showing a resin insulated rolling bearing according to an embodiment of the invention 電食試験の結果を示す図Diagram showing the results of electrolytic corrosion test 絶縁皮膜模擬軸受の電食試験回路を模式的に示す図Diagram schematically showing the electrolytic corrosion test circuit for an insulating film simulated bearing 標準軸受の電食試験回路を模式的に示す図Diagram schematically showing the electrolytic corrosion test circuit for standard bearings
　図１に、この発明の実施形態にかかる樹脂絶縁転がり軸受１を示す。樹脂絶縁転がり軸受１は、外輪２と、外輪２の径方向内側に同軸に配置される内輪３と、外輪２と内輪３の間に組み込まれる複数の転動体４と、その複数の転動体４の周方向間隔を保持する保持器５と、外輪２の外周６と軸方向両側の端面７とに設けられた絶縁性の樹脂皮膜８とを有する。 FIG. 1 shows a resin insulated rolling bearing 1 according to an embodiment of the invention. The resin insulated rolling bearing 1 includes an outer ring 2, an inner ring 3 disposed coaxially inside the outer ring 2 in the radial direction, a plurality of rolling elements 4 incorporated between the outer ring 2 and the inner ring 3, and the plurality of rolling elements 4. It has an insulating resin film 8 provided on the outer periphery 6 of the outer ring 2 and the end surfaces 7 on both sides in the axial direction.
　外輪２の内周には、転動体４が転がり接触する外輪軌道面９と、外輪軌道面９の軸方向の両側に位置する外輪肩部１０とが形成されている。内輪３の外周にも、転動体４が転がり接触する内輪軌道面１１と、内輪軌道面１１の軸方向の両側に位置する内輪肩部１２とが形成されている。転動体４は、ここでは玉である。外輪軌道面９と内輪軌道面１１は、いずれも断面円弧状の溝の内面である。外輪２、内輪３、転動体４はいずれも金属（例えば軸受鋼）で形成されている。 On the inner periphery of the outer ring 2, an outer ring raceway surface 9 with which the rolling elements 4 roll and come into contact, and outer ring shoulders 10 located on both sides of the outer ring raceway surface 9 in the axial direction are formed. Also formed on the outer periphery of the inner ring 3 are an inner ring raceway surface 11 with which the rolling elements 4 come into rolling contact, and inner ring shoulders 12 located on both sides of the inner ring raceway surface 11 in the axial direction. The rolling elements 4 are balls here. The outer ring raceway surface 9 and the inner ring raceway surface 11 are both inner surfaces of grooves having an arcuate cross section. The outer ring 2, the inner ring 3, and the rolling elements 4 are all made of metal (for example, bearing steel).
　外輪２の外周６は、軸方向に沿って外径が変化せず一定の円筒面である。外輪２の軸方向両側の端面７は、軸方向に直角な平面である。外輪２の外周６と外輪２の軸方向両側の端面７との間には、断面円弧状の面取り部１３が形成されている。樹脂皮膜８は、外輪２の外周６を被覆する外周被覆部８ａと、外輪２の面取り部１３を被覆する面取り被覆部８ｂと、外輪２の両側の軸方向端面７を被覆する端面被覆部８ｃとで構成されている。 The outer circumference 6 of the outer ring 2 is a cylindrical surface whose outer diameter does not change along the axial direction and is constant. End surfaces 7 on both sides of the outer ring 2 in the axial direction are planes perpendicular to the axial direction. A chamfered portion 13 having an arcuate cross section is formed between the outer periphery 6 of the outer ring 2 and the end surfaces 7 on both sides of the outer ring 2 in the axial direction. The resin film 8 includes an outer circumferential covering part 8a that covers the outer periphery 6 of the outer ring 2, a chamfer covering part 8b that covers the chamfered part 13 of the outer ring 2, and an end face covering part 8c that covers the axial end faces 7 on both sides of the outer ring 2. It is made up of.
　外周被覆部８ａの膜厚は、５０μｍ以下に設定されている。面取り被覆部８ｂおよび端面被覆部８ｃの膜厚も、５０μｍ以下に設定されている。外周被覆部８ａの膜厚と端面被覆部８ｃの膜厚は同じ大きさである。樹脂皮膜８は、エポキシ樹脂をベースとする樹脂またはポリアミドイミド樹脂をベースとする樹脂を採用すると、一般的に０．０１ｋＶ／μｍ以上の耐電圧を有することができる。 The thickness of the outer peripheral covering portion 8a is set to 50 μm or less. The film thicknesses of the chamfered covering portion 8b and the end face covering portion 8c are also set to 50 μm or less. The thickness of the outer periphery coating portion 8a and the thickness of the end surface coating portion 8c are the same. The resin film 8 can generally have a withstand voltage of 0.01 kV/μm or more when a resin based on epoxy resin or a resin based on polyamideimide resin is used.
　図２に、本願の発明者らが行なった電食試験の結果を示す。この電食試験の試験条件は、以下のとおりである。
　軸受型番：６２０７（内径３５ｍｍ、外径７２ｍｍ、幅１７ｍｍ）
　軸受への印加電圧：ＡＣ±５Ｖ、ＡＣ±１０Ｖ、ＡＣ±２０Ｖの３通り
　電圧の周波数：１０ｋＨｚ
　軸受への負荷荷重：ラジアル荷重１５００Ｎ
　回転数：内輪３０００ｍｉｎ－１
　試験方法：図３に示すように、交流電源３１で標準軸受３２の内輪と外輪の間に交流電圧を印加する試験回路に、６．５ｎＦの静電容量をもつコンデンサ３３と、２００Ωの電気抵抗をもつ抵抗器３４とを組み込むことで、絶縁層として２５μｍ程度の膜厚をもつポリアミドイミド樹脂の樹脂皮膜８を用いた樹脂絶縁転がり軸受１を模擬した（絶縁皮膜模擬軸受）。また、図４に示す試験回路で、標準軸受３２についても同様の試験を行なった（標準軸受）。そして、試験装置３５で標準軸受を運転し、電食により軸受振動が初期振動の２倍となった時点で運転停止させ、試験中の振動データに基づいて軸受振動が初期振動の１０倍となるまでの時間を算出した（図２）。なお、絶縁皮膜模擬軸受の５Ｖおよび標準軸受の２０Ｖのプロットは、１０Ｖ時の標準軸受／絶縁皮膜模擬軸受の試験時間比率から推定したものである。 FIG. 2 shows the results of an electrolytic corrosion test conducted by the inventors of the present application. The test conditions for this electrolytic corrosion test are as follows.
Bearing model number: 6207 (inner diameter 35mm, outer diameter 72mm, width 17mm)
Voltage applied to the bearing: 3 types: AC±5V, AC±10V, AC±20V Voltage frequency: 10kHz
Load on bearing: radial load 1500N
Rotation speed: Inner ring 3000min -1
Test method: As shown in Fig. 3, a capacitor 33 with a capacitance of 6.5 nF and an electric resistance of 200 Ω are used in a test circuit that applies an AC voltage between the inner ring and outer ring of a standard bearing 32 using an AC power supply 31. A resin insulated rolling bearing 1 using a resin film 8 of polyamideimide resin having a film thickness of about 25 μm as an insulating layer was simulated by incorporating a resistor 34 having a thickness of about 25 μm (insulating film simulated bearing). Furthermore, a similar test was conducted on the standard bearing 32 using the test circuit shown in FIG. 4 (standard bearing). Then, the standard bearing is operated in the testing device 35, and the operation is stopped when the bearing vibration becomes twice the initial vibration due to electrolytic corrosion, and the bearing vibration becomes 10 times the initial vibration based on the vibration data during the test. The time it took was calculated (Figure 2). Note that the plots of 5V for the insulation coating simulated bearing and 20V for the standard bearing are estimated from the test time ratio of the standard bearing/insulation coating simulation bearing at 10V.
　この電食試験の結果に示されるように、軸受１に交流電圧を印加した状態で軸受１を運転し、電食により軸受振動が初期振動の１０倍の大きさになったときの、軸受１に印加される交流電圧により軌道面と転動体４の間の接触部を流れる電流密度（縦軸）と、軌道面の定位置での転動体４の総通過回数に交流電圧の周波数を積算した積算値（横軸）との間には一定の関係がある。 As shown in the results of this electrolytic corrosion test, when the bearing 1 is operated with an AC voltage applied to the bearing 1 and the bearing vibration becomes 10 times the initial vibration due to the electrolytic corrosion, the bearing 1 The current density (vertical axis) flowing through the contact area between the raceway surface and the rolling elements 4 due to the AC voltage applied to the raceway surface, and the frequency of the AC voltage are integrated with the total number of passes of the rolling element 4 at a fixed position on the raceway surface. There is a certain relationship with the integrated value (horizontal axis).
　図２において、「絶縁皮膜模擬軸受」の折れ線グラフよりも右側および上側の領域は、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１の耐電食性を確保できない領域である。また、ＯＫ領域１およびＯＫ領域２は、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１の耐電食性を確保するのに必要十分な仕様に対して過剰な仕様となる領域である。ここで、ＯＫ領域１は、横軸において１．６×１０１０（回×Ｈｚ）を上回り、かつ、１．３×１０１２（回×Ｈｚ）を下回る領域である。また、縦軸において９．８×１０－６（Ａ／ｍｍ２）以上の領域である。一方、ＯＫ領域２は、横軸において１．６×１０１０（回×Ｈｚ）を上回り、縦軸において９．８×１０－６（Ａ／ｍｍ２）を下回る領域である。 In FIG. 2, the area to the right and above the line graph of the "insulation film simulated bearing" is an area where the electrical corrosion resistance of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of the electric vehicle cannot be ensured. Further, OK region 1 and OK region 2 are regions where the specifications are excessive compared to the specifications necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of the electric vehicle. Here, the OK region 1 is a region where the frequency exceeds 1.6×10 10 (times×Hz) and falls below 1.3×10 12 (times×Hz) on the horizontal axis. Further, it is a region of 9.8×10 −6 (A/mm 2 ) or more on the vertical axis. On the other hand, OK region 2 is a region where the frequency exceeds 1.6×10 10 (times×Hz) on the horizontal axis and falls below 9.8×10 −6 (A/mm 2 ) on the vertical axis.
　ここで、軌道面の定位置での転動体４の総通過回数に交流電圧の周波数を積算した積算値（横軸）は、軸受１に印加される交流電圧の周波数をｆ（Ｈｚ）、内輪３の回転数をＮｉ（ｍｉｎ－１）、転動体４の直径をＤｗ（ｍｍ）、転動体４の個数をｚ（個）、転動体４のピッチ円径をｄｐ（ｍｍ）、軸受１の運転時間をｈ（ｍｉｎ）としたときに、次式で求めることができる。
Figure JPOXMLDOC01-appb-M000005
 Here, the integrated value (horizontal axis), which is the total number of passes of the rolling elements 4 at a fixed position on the raceway surface multiplied by the frequency of the AC voltage, is the frequency of the AC voltage applied to the bearing 1, f (Hz), and the frequency of the AC voltage applied to the bearing 1. The rotation speed of bearing 3 is Ni (min -1 ), the diameter of rolling element 4 is Dw (mm), the number of rolling elements 4 is z (pieces), the pitch diameter of rolling element 4 is dp (mm), the diameter of bearing 1 is When the operating time is h (min), it can be calculated using the following equation.
Figure JPOXMLDOC01-appb-M000005
　また、軸受１に印加される交流電圧により軌道面と転動体４の間の接触部を流れる電流密度（縦軸）は、軸受１の静電容量（具体的には内輪３の内周と外輪２の外周６との間の樹脂皮膜８を含めた静電容量）をＣ（Ｆ）、軸受１の電気抵抗（具体的には内輪３の内周と外輪２の外周６との間の樹脂皮膜８を含めた電気抵抗）をＲ（Ω）、軸受１に印加される交流電圧の周波数をｆ（Ｈｚ）、軌道面と転動体４の間の接触部（接触楕円）の面積をＡ（ｍｍ２）、軸受１に印加される交流電圧をＶ０（Ｖ）としたときに、次式で求めることができる。
Figure JPOXMLDOC01-appb-M000006
 Furthermore, the current density (vertical axis) flowing through the contact area between the raceway surface and the rolling elements 4 due to the AC voltage applied to the bearing 1 is determined by the capacitance of the bearing 1 (specifically, the inner circumference of the inner ring 3 and the outer ring C (F) is the electrical resistance of the bearing 1 (specifically, the resin between the inner circumference of the inner ring 3 and the outer circumference 6 of the outer ring 2). The electrical resistance (including the coating 8) is R (Ω), the frequency of the AC voltage applied to the bearing 1 is f (Hz), and the area of the contact part (contact ellipse) between the raceway surface and the rolling elements 4 is A ( mm 2 ) and the AC voltage applied to the bearing 1 is V 0 (V), it can be determined by the following equation.
Figure JPOXMLDOC01-appb-M000006
　そして、上記（横軸）の式を、ＯＫ領域１の横軸の範囲をあらわす１．６×１０１０＜（横軸）＜１．３×１０１２の不等式に代入すると、次式となる。
Figure JPOXMLDOC01-appb-M000007
 Then, by substituting the above equation (horizontal axis) into the inequality 1.6×10 10 <(horizontal axis) <1.3×10 12 representing the range of the horizontal axis of OK area 1, the following equation is obtained.
Figure JPOXMLDOC01-appb-M000007
　また、上記（縦軸）の式を、ＯＫ領域２の縦軸の範囲をあらわす０＜（縦軸）＜９．８×１０－６の不等式に代入すると、次式となる。
Figure JPOXMLDOC01-appb-M000008
 Further, by substituting the above equation (vertical axis) into the inequality 0<(vertical axis)<9.8×10 −6 representing the range of the vertical axis of OK area 2, the following equation is obtained.
Figure JPOXMLDOC01-appb-M000008
　ここで、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１では、軸受１に印加される交流電圧の周波数ｆ（Ｈｚ）が２０ｋＨｚ以下、内輪３の回転数Ｎｉが１０００～３００００ｍｉｎ－１、基本動定格荷重が負荷される場合の内輪３の回転数Ｎｉ（ｍｉｎ－１）と軸受１の運転時間ｈ（ｍｉｎ）の積Ｎｉ×ｈが１０６（＝基本定格寿命Ｌ１０）、基本動定格荷重が負荷される場合の接触楕円の面積Ａが２５ｍｍ２、軸受１に印加される交流電圧Ｖ０（Ｖ）は１Ｖ以下である。 Here, in the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of the electric vehicle, the frequency f (Hz) of the AC voltage applied to the bearing 1 is 20 kHz or less, and the rotation speed Ni of the inner ring 3 is 1000 to 30000 min -1. , the product Ni x h of the rotation speed Ni (min -1 ) of the inner ring 3 and the operating time h (min) of the bearing 1 when the basic dynamic load rating is applied is 10 6 (=basic rated life L 10 ), the basic The area A of the contact ellipse when a dynamic load rating is applied is 25 mm 2 , and the AC voltage V 0 (V) applied to the bearing 1 is 1V or less.
　したがって、ＯＫ領域１の横軸の範囲をあらわす１．６×１０１０＜（横軸）＜１．３×１０１２の不等式を整理すると、次式となる。
Figure JPOXMLDOC01-appb-M000009
 Therefore, when the inequality 1.6×10 10 <(horizontal axis) <1.3×10 12 representing the range of the horizontal axis of OK area 1 is rearranged, the following equation is obtained.
Figure JPOXMLDOC01-appb-M000009
　また、ＯＫ領域２の縦軸の範囲をあらわす０＜（縦軸）＜９．８×１０－６の不等式を整理すると、次式となる。
Figure JPOXMLDOC01-appb-M000010
 Further, when the inequality 0<(vertical axis)<9.8×10 −6 , which represents the range of the vertical axis of OK area 2, is rearranged, the following equation is obtained.
Figure JPOXMLDOC01-appb-M000010
　そこで、上記実施形態においては、次式（１）（２）で定義されるＸ，Ｙの組が、１．６＜Ｘ＜１３０、かつ、Ｙ≧２．４５×１０－４を満たす（つまり図２のＯＫ領域１の範囲内にある）か、または、１．６＜Ｘ、かつ、０＜Ｙ＜２．４５×１０－４を満たす（つまり図２のＯＫ領域２の範囲内にある）ように樹脂皮膜８の仕様が設定されている。
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000012
 Therefore, in the above embodiment, the pair of X and Y defined by the following equations (1) and (2) satisfies 1.6<X<130 and Y≧2.45×10 −4 (that is, 1.6<X and 0<Y<2.45×10 −4 (that is, within OK region 2 of FIG. 2) ) The specifications of the resin film 8 are set as follows.
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000012
　ところで、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１の絶縁層として樹脂皮膜８を用いる場合、従来、絶縁転がり軸受１の耐電食性を確保するには、樹脂皮膜８の仕様（膜厚、静電容量、電気抵抗など）をどのように設定すればよいかが不明であった。そのため従来においては、絶縁転がり軸受１の樹脂皮膜８の仕様が、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１の耐電食性を確保するのに必要十分な仕様に対して過剰な仕様となっており、無用のコストが発生している可能性があった。 By the way, when using the resin film 8 as an insulating layer of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of an electric vehicle, conventionally, in order to ensure the electrical corrosion resistance of the insulated rolling bearing 1, the specifications of the resin film 8 (membrane It was unclear how to set the parameters (thickness, capacitance, electrical resistance, etc.). Therefore, in the past, the specifications of the resin coating 8 of the insulated rolling bearing 1 were excessive compared to the specifications necessary and sufficient to ensure the electrolytic corrosion resistance of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of the electric vehicle. This may have resulted in unnecessary costs.
　この問題に対し、上記実施形態の樹脂絶縁転がり軸受１は、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１の一般的な使用条件、すなわち、軸受１に印加される交流電圧の周波数が２０ｋＨｚ以下、電圧が１Ｖ以下、内輪３の回転数が３００００ｍｉｎ－１以下、軸受１に作用する動等価ラジアル荷重が基本定格荷重以下の使用条件において、電食で軸受振動が初期振動の１０倍の大きさになるまでの軸受１の総回転数が、軸受１の基本定格寿命に対応する回転数かそれ以下となっており、樹脂皮膜８の仕様が、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受１の耐電食性を確保するのに必要十分であり、低コストである。 To solve this problem, the resin insulated rolling bearing 1 of the above embodiment meets the general usage conditions of the insulated rolling bearing 1 that supports the main shaft 20 of the electric motor of an electric vehicle, that is, the frequency of the AC voltage applied to the bearing 1. Under operating conditions in which the voltage is 20 kHz or less, the voltage is 1 V or less, the rotational speed of the inner ring 3 is 30,000 min -1 or less, and the dynamic equivalent radial load acting on the bearing 1 is less than the basic rated load, the bearing vibration will be 10 times the initial vibration due to electrolytic corrosion. The total number of revolutions of the bearing 1 until the size of It is necessary and sufficient to ensure the electrolytic corrosion resistance of the supported insulated rolling bearing 1, and is low cost.
　また、上記実施形態の樹脂絶縁転がり軸受１は、樹脂皮膜８の膜厚が５０μｍ以下に設定されているので、温度変化による樹脂皮膜８の膜厚の変化が小さく、高温状態のときに、樹脂皮膜８の膨張により、外輪２とモータハウジング２１の間に過大な締め代が生じたり、一方、低温状態のときに、外輪２とモータハウジング２１の間に過大な隙間が生じたりするのを防止することができる。そのため、電気自動車の電動モータの主軸２０を支持する絶縁転がり軸受として使用するときに、外輪２とモータハウジング２１の間のはめあい隙間を適切に設定することができる。 In addition, in the resin insulated rolling bearing 1 of the above embodiment, the thickness of the resin film 8 is set to 50 μm or less, so the change in the thickness of the resin film 8 due to temperature changes is small, and the resin insulated rolling bearing 1 in the high temperature state Prevents the expansion of the film 8 from creating an excessive interference between the outer ring 2 and the motor housing 21, and on the other hand, prevents the creation of an excessive gap between the outer ring 2 and the motor housing 21 when the temperature is low. can do. Therefore, when used as an insulated rolling bearing that supports the main shaft 20 of an electric motor of an electric vehicle, the fitting gap between the outer ring 2 and the motor housing 21 can be appropriately set.
　上記実施形態では、外輪２の外周６および外輪２の両側の軸方向端面７に樹脂皮膜８を有する樹脂絶縁転がり軸受１を例に挙げて説明したが、この発明は、外輪２の片側の軸方向端面７にのみ樹脂皮膜８を有する樹脂絶縁転がり軸受についても同様に適用することができ、また、内輪３の内周および内輪３の両側または片側の軸方向端面に樹脂皮膜８を有する樹脂絶縁転がり軸受についても同様に適用することができる。また、上記実施形態では、外輪２の内周に樹脂皮膜が設けられていない樹脂絶縁転がり軸受１を例に挙げて説明したが、この発明は、外輪２の内周に樹脂皮膜８を追加して設けた樹脂絶縁転がり軸受についても同様に適用することができる。同様に、内輪３の内周と軸方向端面に樹脂皮膜８を設ける場合、内輪３の外周にも樹脂皮膜８を追加して設けるようにしてもよい。 In the above embodiment, the resin insulated rolling bearing 1 which has the resin film 8 on the outer periphery 6 of the outer ring 2 and the axial end faces 7 on both sides of the outer ring 2 has been described as an example. The same can be applied to a resin insulated rolling bearing having a resin film 8 only on the directional end face 7, and also a resin insulated rolling bearing having a resin film 8 on the inner periphery of the inner ring 3 and the axial end face on both sides or one side of the inner ring 3. The same applies to rolling bearings. Further, in the above embodiment, the resin insulated rolling bearing 1 in which the inner circumference of the outer ring 2 is not provided with a resin film has been described as an example, but the present invention adds a resin film 8 to the inner circumference of the outer ring 2. The same can be applied to resin insulated rolling bearings provided in the same way. Similarly, when the resin film 8 is provided on the inner periphery and axial end face of the inner ring 3, the resin film 8 may be additionally provided on the outer periphery of the inner ring 3.
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.
１　　　樹脂絶縁転がり軸受
２　　　外輪
３　　　内輪
４　　　転動体
６　　　外周
７　　　端面
８　　　樹脂皮膜 1 Resin insulated rolling bearing 2 Outer ring 3 Inner ring 4 Rolling element 6 Outer periphery 7 End face 8 Resin film

Claims (2)

  1. 　外輪（２）と、
    　前記外輪（２）の径方向内側に同軸に配置される内輪（３）と、
    　前記外輪（２）と前記内輪（３）の間に組み込まれる複数の転動体（４）と、
    　前記外輪（２）の外周（６）および前記外輪（２）の軸方向端面（７）、または前記内輪（３）の内周および前記内輪（３）の軸方向端面に設けられた絶縁性の樹脂皮膜（８）と、を有する樹脂絶縁転がり軸受において、
    　前記転動体（４）の直径をＤｗ（ｍｍ）、前記転動体（４）の個数をｚ（個）、前記転動体（４）のピッチ円径をｄｐ（ｍｍ）、前記内輪（３）の内周と前記外輪（２）の外周（６）との間の前記樹脂皮膜（８）を含めた静電容量をＣ（Ｆ）、前記内輪（３）の内周と前記外輪（２）の外周（６）との間の前記樹脂皮膜（８）を含めた電気抵抗をＲ（Ω）としたときに、次式（１）（２）で定義されるＸ，Ｙの組が、１．６＜Ｘ＜１３０、かつ、Ｙ≧２．４５×１０－４を満たすか、または、１．６＜Ｘ、かつ、０＜Ｙ＜２．４５×１０－４を満たすことを特徴とする樹脂絶縁転がり軸受。
    Figure JPOXMLDOC01-appb-M000001
    Figure JPOXMLDOC01-appb-M000002
         an outer ring (2);
    an inner ring (3) disposed coaxially inside the outer ring (2) in the radial direction;
    a plurality of rolling elements (4) incorporated between the outer ring (2) and the inner ring (3);
    An insulating ring provided on the outer circumference (6) of the outer ring (2) and the axial end face (7) of the outer ring (2), or on the inner circumference of the inner ring (3) and the axial end face of the inner ring (3). In a resin insulated rolling bearing having a resin film (8),
    The diameter of the rolling element (4) is Dw (mm), the number of the rolling elements (4) is z (pieces), the pitch circle diameter of the rolling element (4) is dp (mm), the inner ring (3) is The capacitance including the resin film (8) between the inner circumference and the outer circumference (6) of the outer ring (2) is C(F), and the capacitance between the inner circumference of the inner ring (3) and the outer ring (2) is C(F). When the electrical resistance including the resin film (8) between the outer periphery (6) and the outer periphery (6) is R (Ω), the pair of X and Y defined by the following formulas (1) and (2) is 1. A resin that satisfies 6<X<130 and Y≧2.45×10 −4 or 1.6<X and 0<Y<2.45×10 −4 Insulated rolling bearing.
    Figure JPOXMLDOC01-appb-M000001
    Figure JPOXMLDOC01-appb-M000002
  2. 　前記樹脂皮膜（８）は、前記外輪（２）の外周（６）および前記外輪（２）の軸方向端面（７）に設けられ、
    　前記樹脂皮膜（８）の膜厚が５０μｍ以下に設定されている請求項１に記載の樹脂絶縁転がり軸受。     The resin film (8) is provided on the outer periphery (6) of the outer ring (2) and the axial end surface (7) of the outer ring (2),
    The resin insulated rolling bearing according to claim 1, wherein the resin film (8) has a thickness of 50 μm or less.
PCT/JP2023/028523 2022-08-10 2023-08-04 Resin insulated rolling bearing WO2024034529A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008169959A (en) * 2007-01-15 2008-07-24 Nsk Ltd Insulated rolling bearing for preventing electric corrosion
JP2013015180A (en) * 2011-07-04 2013-01-24 Nsk Ltd Single-row deep-groove type radial ball bearing
JP2021110385A (en) * 2020-01-09 2021-08-02 株式会社ジェイテクト Rolling bearing and manufacturing method of the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008169959A (en) * 2007-01-15 2008-07-24 Nsk Ltd Insulated rolling bearing for preventing electric corrosion
JP2013015180A (en) * 2011-07-04 2013-01-24 Nsk Ltd Single-row deep-groove type radial ball bearing
JP2021110385A (en) * 2020-01-09 2021-08-02 株式会社ジェイテクト Rolling bearing and manufacturing method of the same

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