WO2023248266A1 - Double-row deep-groove ball bearing and magnetic bearing device - Google Patents

Double-row deep-groove ball bearing and magnetic bearing device Download PDF

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Publication number
WO2023248266A1
WO2023248266A1 PCT/JP2022/024441 JP2022024441W WO2023248266A1 WO 2023248266 A1 WO2023248266 A1 WO 2023248266A1 JP 2022024441 W JP2022024441 W JP 2022024441W WO 2023248266 A1 WO2023248266 A1 WO 2023248266A1
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WO
WIPO (PCT)
Prior art keywords
inner ring
raceway groove
rolling bearing
rotating shaft
bearing
Prior art date
Application number
PCT/JP2022/024441
Other languages
French (fr)
Japanese (ja)
Inventor
和博 木村
浩 小野
Original Assignee
株式会社ジェイテクト
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ジェイテクト filed Critical 株式会社ジェイテクト
Priority to PCT/JP2022/024441 priority Critical patent/WO2023248266A1/en
Priority to TW111145598A priority patent/TW202400912A/en
Publication of WO2023248266A1 publication Critical patent/WO2023248266A1/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
    • F16C19/08—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 two or more rows of 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
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
    • 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
    • F16C33/60—Raceways; Race rings divided or split, e.g. comprising two juxtaposed rings

Definitions

  • the present disclosure relates to a double-row deep groove ball bearing and a magnetic bearing device.
  • a turbomolecular pump which is a mechanical vacuum pump, is equipped with a magnetic bearing that supports a rotating shaft without contact. If an abnormality occurs in the magnetic bearing, it becomes impossible to support the rotating shaft. Therefore, the turbo-molecular pump includes a rolling bearing that supports the rotating shaft in the event of an abnormality in the magnetic bearing.
  • the rolling bearing is called a touchdown bearing.
  • Patent Document 1 discloses a turbomolecular pump including a magnetic bearing and a touchdown bearing.
  • the turbo molecular pump disclosed in Patent Document 1 includes, as a touchdown bearing, a first rolling bearing that can support the upper part of the rotating shaft, and a second rolling shaft that can support the lower part of the rotating shaft.
  • the first rolling bearing and the second rolling bearing are in a non-contact state with the rotating shaft.
  • the first rolling bearing and the second rolling bearing support the rotating shaft.
  • the first rolling bearing supports the rotating shaft in the radial direction
  • the second rolling bearing supports the rotating shaft in the radial and axial directions.
  • the first rolling bearing is a single row first rolling bearing.
  • the first rolling bearing 90 When the weight of the rotating shaft increases, the first rolling bearing receives a large radial load from the rotating shaft.
  • the load capacity of the first rolling bearing can be increased by increasing the diameter of the balls, which are rolling elements.
  • the volume of the first rolling bearing increases in the axial and radial directions, and as a result, the housing of the turbomolecular pump increases in size.
  • the first rolling bearing 90 includes one inner ring 91, one outer ring 98, a plurality of rolling elements 95 in the first row L1, and a plurality of rolling elements 95 in the second row L2.
  • a rolling element 92 is provided.
  • the inner ring 91 has an inner ring raceway groove 96 in a first row L1 and an inner ring raceway groove 93 in a second row L2.
  • the outer ring 98 has an outer ring raceway groove 97 in a first row L1 and an outer ring raceway groove 94 in a second row L2.
  • the bearing portion of the first row L1 includes an inner raceway groove 96 of the first row L1, an outer raceway groove 97 of the first row L1, and a plurality of rolling elements 95 of the first row L1.
  • the bearing portion of the second row L2 includes an inner raceway groove 93 of the second row L2, an outer raceway groove 94 of the second row L2, and a plurality of rolling elements 92 of the second row L2.
  • the first rolling bearing 90 is a double-row first rolling bearing.
  • the rotating shaft 99 may tilt and come into contact with the rolling bearing 90.
  • the rotating shaft 99 is biased in contact with the bearing portion of the first row L1 of the inner ring 91. Since the inner ring 91 includes the inner ring raceway groove 96 of the first row L1 and the inner ring raceway groove 93 of the second row L2, the inner ring raceway groove 96 of the first row L1 and the inner ring raceway groove 93 of the second row L2 are the same. Rotate at rotational speed. Therefore, the balls 95 roll in the inner ring raceway groove 96 and the outer ring raceway groove 97 in the bearing portion of the first row L1 where the radial load is large.
  • the rolling of the balls 95 causes the inner ring 91 to rotate relative to the outer ring 98.
  • the balls 92 may slide against the inner ring raceway groove 93 and the outer ring raceway groove 94, causing seizure.
  • the present disclosure provides a double-row deep groove ball bearing that can suppress slippage between the balls and raceway grooves even when the rotating shafts come into contact with each other at an angle.
  • An object of the present invention is to provide a magnetic bearing device including a double-row deep groove ball bearing.
  • the double row deep groove ball bearing of the present disclosure includes: an outer ring having a first outer ring raceway groove and a second outer ring raceway groove on the inner periphery; a first inner ring having a first inner ring raceway groove on its outer periphery; a second inner ring having a second inner ring raceway groove on its outer periphery; a plurality of first balls provided between the first inner raceway groove and the first outer raceway groove; a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove; Equipped with The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove, The first inner ring and the second inner ring are separate bodies.
  • the magnetic bearing device of the present disclosure includes: housing and a rotating shaft provided within the housing; a first rolling bearing capable of supporting the rotating shaft; a second rolling bearing capable of supporting the rotating shaft; a radial magnetic bearing capable of supporting the rotating shaft in a radial direction; an axial magnetic bearing capable of supporting the rotating shaft in the axial direction; Equipped with The first rolling bearing is provided on a first side in the axial direction of the rotating shaft with respect to the center of gravity of the rotating shaft, and the second rolling bearing is provided on a first side of the rotating shaft with respect to the center of gravity of the rotating shaft.
  • the double-row deep groove ball bearing of the present disclosure even if the rotating shaft is tilted, it is possible to suppress slippage between the balls and the raceway grooves.
  • the magnetic bearing device of the present disclosure even if the rotating shaft is tilted, it is possible to suppress slippage between the balls and the raceway grooves.
  • FIG. 1 is a sectional view showing an example of a magnetic bearing device.
  • FIG. 2 is a cross-sectional view of the first rolling bearing.
  • FIG. 3 is a sectional view showing another form of the first rolling bearing.
  • FIG. 4 is a sectional view showing still another form of the first rolling bearing.
  • FIG. 5 is a sectional view showing still another modification of the first rolling bearing shown in FIG. 2.
  • FIG. 6 is a sectional view showing a modification of the first rolling bearing shown in FIG. 3.
  • FIG. FIG. 7 is a sectional view showing still another modification of the first rolling bearing shown in FIG. 3.
  • FIG. 8 is a sectional view showing a modification of the first rolling bearing shown in FIG. 4.
  • FIG. 9 is a sectional view showing still another modification of the first rolling bearing shown in FIG. 4.
  • FIG. 10 is a sectional view of a first conventional rolling bearing.
  • the double row deep groove ball bearing of the present disclosure includes: an outer ring having a first outer ring raceway groove and a second outer ring raceway groove on the inner periphery; a first inner ring having a first inner ring raceway groove on its outer periphery; a second inner ring having a second inner ring raceway groove on its outer periphery; a plurality of first balls provided between the first inner ring raceway groove and the first outer ring raceway groove; a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove; Equipped with The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove, The first inner ring and the second inner ring are separate bodies.
  • the first inner ring can rotate independently in relation to the second inner ring, and the second inner ring can rotate independently in relation to the first inner ring. It becomes possible. A degree of freedom in rotation (rotational speed) is obtained between the first inner ring and the second inner ring. For this reason, even if the tilting rotating shaft contacts the first inner ring unevenly, slippage between the second inner ring and outer ring and the second ball is suppressed.
  • the first rolling bearing supports the rotating shaft in the radial direction.
  • the first inner ring can rotate independently in relation to the second inner ring.
  • a degree of freedom in rotation (rotational speed) is obtained between the first inner ring and the second inner ring. For this reason, even if the tilting rotating shaft contacts the first inner ring unevenly, slippage between the second inner ring and outer ring and the second ball is suppressed.
  • the rotating shaft 11 is provided within the housing 12.
  • the rotating shaft 11 includes a shaft main body 66 and a rotating block 64 that rotates integrally with the shaft main body 66.
  • the rotating block 64 has a plurality of rotary blades 65.
  • the rotary blades 65 and the fixed blades 63 are arranged alternately in the axial direction.
  • the rotating shaft 11 has a disk portion 67 at its lower part.
  • the rotating shaft 11 is rotatable around the central axis C within the housing 12.
  • the housing 12 is provided with radial magnetic bearings 13a, 13b and axial magnetic bearings 14a, 14b.
  • the first axial magnetic bearing 14a and the second axial magnetic bearing 14b are provided apart in the axial direction.
  • the first axial magnetic bearing 14a is provided on the disk portion 67.
  • the second axial magnetic bearing 14b is provided below the disk portion 67.
  • These axial magnetic bearings 14a and 14b can support the rotating shaft 11 without contact.
  • the axial magnetic bearings 14a and 14b have a function of supporting the rotating shaft 11 in the axial direction by magnetic force.
  • the axial magnetic bearings 14a, 14b employ a conventionally known configuration.
  • the first rolling bearing 16 is provided above the center of gravity G of the rotating shaft 11.
  • the second rolling bearing 17 is provided below the first rolling bearing 16 and below the center of gravity G of the rotating shaft 11. The first rolling bearing 16 and the second rolling bearing 17 will be explained below.
  • FIG. 2 is a cross-sectional view of the first rolling bearing 16.
  • FIG. 2 is a sectional view taken along a plane including the central axis C.
  • the first rolling bearing 16 is a double-row deep groove ball bearing, and is capable of supporting the rotating shaft 11 in the radial direction.
  • the rotating shaft 11 is indicated by a chain double-dashed line.
  • the first rolling bearing 16 is attached to the housing 12 around the central axis C.
  • the first rolling bearing 16 includes one outer ring 20, one first inner ring 21, one second inner ring 22, a plurality of first balls 23, and a plurality of second balls 24.
  • the first inner ring 21 and the second inner ring 22 are separate bodies and are provided separately.
  • the outer ring 20 is one bearing ring that is shared by the first inner ring 21 and the second inner ring 22.
  • the outer ring 20 is fixed to a part of the inner peripheral surface 70 of the housing 12.
  • the outer ring 20 is a cylindrical member.
  • the outer peripheral surface of the outer ring 20 is a bearing outer diameter surface.
  • a first outer ring raceway groove 26 and a second outer ring raceway groove 27 are provided on the inner periphery of the outer ring 20 .
  • the outer ring 20 has a first portion 20a and a second portion 20b that is integral with the first portion 20a.
  • the first outer ring raceway groove 26 is provided in the first portion 20a.
  • the second outer ring raceway groove 27 is provided in the second portion 20b.
  • the first portion 20a is a part of one cylindrical member, and the second portion 20b is the remaining part of the one cylindrical member.
  • the first portion 20a functions as an outer ring of the first row L1 of the first rolling bearing 16.
  • the second portion 20b functions as an outer ring of the second row L2 of the first rolling bearing 16.
  • the first portion 20a is located above the second portion 20b.
  • the first outer ring raceway groove 26 is located above the second outer ring raceway groove 27.
  • the outer ring 20 has a shoulder 36a above the first outer ring raceway groove 26.
  • the outer ring 20 has a shoulder 36b below the second outer ring raceway groove 27.
  • the outer ring 20 has an intermediate shoulder 30 between the first outer ring raceway groove 26 and the second outer ring raceway groove 27 .
  • the intermediate shoulder 30 is provided continuously in the circumferential direction.
  • the inner peripheral surface of the intermediate shoulder 30 has a smaller inner diameter than the raceway grooves 26 and 27.
  • the first inner ring 21 is a cylindrical member that is shorter in the axial direction than the outer ring 20.
  • the first inner ring raceway groove 28 is provided on the outer periphery of the first inner ring 21 .
  • the first inner ring 21 has shoulders 37 on both sides (upper and lower sides) of the first inner ring raceway groove 28 in the axial direction.
  • the first inner ring 21 has a first bearing inner diameter surface 31 located at the center in the axial direction, and a first chamfer provided on the upper and lower sides of the first bearing inner diameter surface 31 on its inner circumference. 32.
  • the first bearing inner diameter surface 31 is a cylindrical surface centered on the central axis C.
  • the inner diameter of the first inner ring 21 is larger than the outer diameter of the support portion of the rotating shaft 11 .
  • the second inner ring 22 is a cylindrical member that is shorter in the axial direction than the outer ring 20.
  • the second inner ring raceway groove 29 is provided on the outer periphery of the second inner ring 22.
  • the second inner ring 22 has shoulders 38 on both sides (upper and lower sides) of the second inner ring raceway groove 29 in the axial direction.
  • the second inner ring 22 has, on its inner periphery, a second bearing inner diameter surface 33 located at the center in the axial direction, and second chamfers provided on the upper and lower sides of the second bearing inner diameter surface 33, respectively. 34.
  • the second bearing inner diameter surface 33 is a cylindrical surface centered on the central axis C.
  • the inner diameter of the second inner ring 22 is larger than the outer diameter of the support portion of the rotating shaft 11 .
  • the inner diameter of the first inner ring 21 is the same as the inner diameter of the second inner ring 22.
  • the diameter of the first bearing inner diameter surface 31 is the inner diameter of the first inner ring 21
  • the diameter of the second bearing inner diameter surface 33 is the inner diameter of the second inner ring 22. Therefore, the diameter of the first bearing inner diameter surface 31 is the same as the diameter of the second bearing inner diameter surface 33.
  • the first inner ring 21 is located above the second inner ring 22.
  • the first inner ring 21 becomes the inner ring of the first row L1 of the first rolling bearing 16.
  • the second inner ring 22 becomes the inner ring of the second row L2 of the first rolling bearing 16.
  • a gap E is provided between the first inner ring 21 and the second inner ring 22 in the axial direction.
  • the gap E is set to an axial dimension that prevents the first inner ring 21 and the second inner ring 22 from coming into contact with each other even if the first inner ring 21 and the second inner ring 22 are displaced in the axial direction.
  • the plurality of first balls 23 are provided between the first inner ring raceway groove 28 and the first outer ring raceway groove 26.
  • the plurality of second balls 24 are provided between the second inner ring raceway groove 29 and the second outer ring raceway groove 27.
  • the first balls 23 serve as rolling elements of the first row L1 of the first rolling bearing 16.
  • the second balls 24 serve as rolling elements of the second row L2 of the first rolling bearing 16.
  • Each of the first outer ring raceway groove 26, the second outer ring raceway groove 27, the first inner ring raceway groove 28, and the second inner ring raceway groove 29 has an arc shape in a cross section including the central axis C.
  • the bearing portion of the first row L1 is constituted by a first portion 20a of the outer ring 20, a first inner ring 21, and a plurality of first balls 23.
  • the bearing portion of the second row L2 is constituted by the second portion 20b of the outer ring 20, the second inner ring 22, and the plurality of second balls 24.
  • the bearing portions in the first row L1 and the bearing portions in the second row L2 are each deep groove ball bearings.
  • the pitch diameter D1 of the ball set including the plurality of first balls 23 is the same as the pitch diameter D2 of the ball set including the plurality of second balls 24.
  • the diameter d1 of the first ball 23 is the same as the diameter d2 of the second ball 24.
  • the outer ring 20, the first inner ring 21, and the second inner ring 22 are made of, for example, high-speed tool steel, bearing steel, or stainless steel.
  • the first ball 23 and the second ball 24 are manufactured from high speed tool steel, bearing steel, stainless steel, or ceramics.
  • a coating is formed on each surface of the first outer ring raceway groove 26, the second outer ring raceway groove 27, the first inner ring raceway groove 28, and the second inner ring raceway groove 29.
  • the film is a solid lubricant.
  • the first rolling bearing 16 is a full ball bearing.
  • the bearing portions of the first row L1 and the bearing portions of the second row L2 are each not provided with a retainer. Adjacent first balls 23 and first balls 23 can come into contact with each other. Adjacent second balls 24 can come into contact with each other.
  • the second rolling bearing 17 can support the lower part of the rotating shaft 11.
  • the second rolling bearing 17 is composed of two angular ball bearings 18, 18.
  • the second rolling bearing 17 is a combination of a first angular contact ball bearing 18 and a second angular contact ball bearing 18 in a front-on arrangement.
  • the second rolling bearing 17 can support the rotating shaft 11 in the radial direction and the axial direction.
  • the third outer ring 39 and the fourth outer ring 40 are fixed to the housing 12 with their front surfaces in contact with each other in the axial direction.
  • the third inner ring 41 and the fourth inner ring 42 are provided so that their respective back surfaces are in contact with each other in the axial direction.
  • the inner diameter of each of the third inner ring 41 and the fourth inner ring 42 is larger than the outer diameter of the support portion of the rotating shaft 11.
  • the first rolling bearing 16 is able to support the rotating shaft 11 in the radial direction.
  • the first rolling bearing 16 cannot support the rotating shaft 11 in the radial direction. It becomes possible.
  • at least one of the first inner ring 21 and the second inner ring 22 comes into contact with the rotating shaft 11, and it becomes possible to support the rotating shaft 11 in the radial direction. .
  • the second rolling bearing 17 is able to support the rotating shaft 11 in the radial and axial directions.
  • the second rolling bearing 17 supports the rotating shaft 11 in the radial and axial directions. becomes possible. That is, when the rotating shaft 11 is no longer supported by the magnetic force, at least one of the third inner ring 41 and the fourth inner ring 42 comes into contact with the rotating shaft 11, and the second rolling bearing 17 supports the rotating shaft 11 in the radial direction. It becomes possible to support the The large diameter portion 11a of the rotating shaft 11 comes into contact with the third inner ring 41 in the axial direction, and the second rolling bearing 17 can support the rotating shaft 11 in the axial direction.
  • the rotating shaft 11 Before the rotating shaft 11, which becomes unstable, comes into contact with the radial magnetic bearings 13a and 13b, the rotating shaft 11 is supported by the first rolling bearing 16 and the second rolling bearing 17. Before the rotating shaft 11 comes into contact with the axial magnetic bearings 14a, 14b, which becomes unstable, the rotating shaft 11 is supported by the second rolling bearing 17.
  • FIG. 4 is a sectional view showing still another form of the first rolling bearing 16.
  • the diameter d1 of the first ball 23 is larger than the diameter d2 of the second ball 24.
  • the configuration excluding the diameter d1 of the first ball 23 and the diameter d2 of the second ball 24 of the first rolling bearing 16 shown in FIG. The configuration is the same except for the diameter d1 of the ball 23 and the diameter d2 of the second ball 24, and the explanation thereof will be omitted.
  • the reference numerals of the structure of the first rolling bearing 16 shown in FIG. 4 are the same as the reference numerals of the structure of the first rolling bearing 16 shown in FIG.
  • the first rolling bearing 16 of each of the above embodiments is provided with the first outer ring raceway groove 26 and the second outer ring raceway groove 27 on the inner periphery.
  • one first inner ring 21 having a first inner ring raceway groove 28 on its outer periphery; and one second inner ring 21 having a second inner ring raceway groove 29 on its outer periphery.
  • the first rolling bearing 16 of each of the above embodiments it is also possible to achieve the following effects.
  • the radial load received by the first rolling bearings 16 from the rotating shaft 11 in an inclined state is received by the bearings in the upper first row L1.
  • the load is distributed between the load and the load received by the bearing section of the lower second row L2.
  • the first rolling bearings 16 of each of the above-mentioned configurations have a radial load that is applied from the rotating shaft 11 to the bearings in the first row L1, and a radial load that is received from the rotating shaft 11 to the bearings in the second row L2.
  • the difference can be made smaller than that of the double-row first rolling bearing 90 of the prior art.
  • the first rolling bearing 16 of each of the above embodiments can have a load capacity larger than that of the conventional single-row first rolling bearing.
  • the first rolling bearing 16 of each of the above embodiments is a full ball bearing.
  • the first rolling bearing 16 of each type has grooves for the balls 23 and 24 in each bearing ring to enable assembly. The groove will be explained below. Note that in each of the following examples, the first inner ring 21 is provided above the second inner ring 22.
  • the first rolling bearing 16 is provided with a groove 71 for the second ball 24 at the center of the inner circumference of the outer ring 20 in the axial direction.
  • the insertion groove 71 for the second ball 24 has a shape obtained by removing a part of the intermediate shoulder 30 in the circumferential direction, and connects the first outer ring raceway groove 26 and the second outer ring raceway groove 27.
  • a groove 74 for the second ball 24 is provided on the outer periphery of the second inner ring 22 to connect the upper inner ring side surface 73 and the second inner ring raceway groove 29 .
  • the groove 74 for the second ball 24 has a shape obtained by removing a portion of the upper shoulder 38 of the second inner ring 22 in the circumferential direction.
  • the insertion groove 52 for the first ball 23 is provided on the inner periphery of the outer ring 20 so as to connect the upper outer ring side surface 51 and the first outer ring raceway groove 26 .
  • the groove 52 for the first ball 23 has a shape obtained by removing a portion of the upper shoulder 36a of the outer ring 20 in the circumferential direction.
  • the insertion groove 54 for the first ball 23 is provided on the outer periphery of the first inner ring 21 so as to connect the upper inner ring side surface 53 and the first inner ring raceway groove 28 .
  • the insertion groove 71 for the first ball 23 has a shape obtained by removing a part of the intermediate shoulder 30 in the circumferential direction, and connects the first outer ring raceway groove 26 and the second outer ring raceway groove 27.
  • the insertion groove 76 for the first ball 23 is provided on the outer periphery of the first inner ring 21 so as to connect the lower inner ring side surface 75 and the first inner ring raceway groove 28 .
  • the groove 76 for the first ball 23 has a shape obtained by removing a portion of the lower shoulder 37 of the first inner ring 21 in the circumferential direction.
  • FIG. 8 is a sectional view showing a modification of the first rolling bearing 16 shown in FIG. 4.
  • FIG. The fifth example shown in FIG. 8 is different from the first rolling bearing 16 shown in FIG. 4 in the configuration of the insertion groove.
  • the configuration of the first rolling bearing 16 shown in FIG. 8 except for the insertion groove is the same as the configuration of the first rolling bearing 16 shown in FIG. 4 except for the insertion groove, and the description thereof will be omitted.
  • the reference numerals of the first rolling bearing 16 shown in FIG. 8 have the same configuration as the first rolling bearing 16 shown in FIG. 4 except for the insertion groove.
  • the code is the same as that of No.16.
  • FIG. 8 which is a fifth example, is the same as that of the first rolling bearing 16 shown in FIG. 5, which is a second example, and the description thereof will be omitted.
  • the reference numerals of the insert grooves of the first rolling bearing 16 shown in FIG. 8, which have the same configuration as the insert grooves of the first rolling bearing 16 shown in FIG. is the same as In the first rolling bearing 16 of the fifth example, the bearing parts of the second row L2 are assembled, and then the bearing parts of the first row L1 are assembled.
  • FIG. 9 is a sectional view showing still another modification of the first rolling bearing 16 shown in FIG.
  • the sixth example shown in FIG. 9 is different from the first rolling bearing 16 shown in FIG. 4 in the configuration of the insertion groove.
  • the configuration of the first rolling bearing 16 shown in FIG. 9 except for the insertion groove is the same as the configuration of the first rolling bearing 16 shown in FIG. 4 except for the insertion groove, and the description thereof will be omitted.
  • the code is the same as that of No.16.
  • the insertion groove of the first rolling bearing 16 shown in FIG. 9, which is the sixth example is the same as that of the first rolling bearing 16 shown in FIG.
  • Magnetic bearing device 11 Rotating shaft 12 Housing 13a, 13b Radial magnetic bearing 14a, 14b Axial magnetic bearing 16 First rolling bearing (double row deep groove ball bearing) 17 Second rolling bearing 20 Outer ring 20a First part 20b Second part 21 First inner ring 22 Second inner ring 23 First ball 24 Second ball 26 First outer ring raceway groove 27 Second outer ring raceway groove 28 First inner ring raceway groove 29 Second inner ring raceway groove 51 Outer ring side surface 52 Insertion groove 53 Inner ring side surface 54 Insertion groove E Gap G Center of gravity position

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rolling Contact Bearings (AREA)
  • Bearings For Parts Moving Linearly (AREA)

Abstract

This double-row deep-groove ball bearing comprises an outer ring (20) in which a first outer ring raceway groove (26) and a second outer ring raceway groove (27) are provided to the inner periphery, a first inner ring (21) in which a first inner ring raceway groove (28) is provided to the outer periphery, a second inner ring (22) in which a second inner ring raceway groove (29) is provided to the outer periphery, a plurality of first balls (23) provided between the first inner ring raceway groove (28) and the first outer ring raceway groove (26), and a plurality of second balls (24) provided between the second inner ring raceway groove (29) and the second outer ring raceway groove (27). The outer ring (20) has a first portion (20a) where the first outer ring raceway groove (26) is provided, and a second portion (20b) where the second outer ring raceway groove (27) is provided, the second portion (20b) being integrated with the first portion (20a). The first inner ring (21) and the second inner ring (22) are separate from one another.

Description

複列深溝玉軸受及び磁気軸受装置Double row deep groove ball bearings and magnetic bearing devices
　本開示は、複列深溝玉軸受及び磁気軸受装置に関する。 The present disclosure relates to a double-row deep groove ball bearing and a magnetic bearing device.
　機械式真空ポンプであるターボ分子ポンプは、回転軸を非接触で支持する磁気軸受を備える。磁気軸受に異常が生じた場合、回転軸の支持が不能となる。そこで、ターボ分子ポンプは、磁気軸受の異常の際に回転軸を支持する転がり軸受を備える。その転がり軸受はタッチダウン軸受と呼ばれる。特許文献１に、磁気軸受及びタッチダウン軸受を備えるターボ分子ポンプが開示されている。 A turbomolecular pump, which is a mechanical vacuum pump, is equipped with a magnetic bearing that supports a rotating shaft without contact. If an abnormality occurs in the magnetic bearing, it becomes impossible to support the rotating shaft. Therefore, the turbo-molecular pump includes a rolling bearing that supports the rotating shaft in the event of an abnormality in the magnetic bearing. The rolling bearing is called a touchdown bearing. Patent Document 1 discloses a turbomolecular pump including a magnetic bearing and a touchdown bearing.
特開２０１８－９６６３号公報JP 2018-9663 Publication
　特許文献１に開示のターボ分子ポンプは、タッチダウン軸受として、回転軸の上部を支持可能とする第一の転がり軸受、及び、回転軸の下部を支持可能とする第二の転がり軸を備える。磁気軸受が機能している正常な運転状態では、第一の転がり軸受及び第二の転がり軸受は、回転軸と非接触の状態にある。磁気軸受が、その不具合によって、回転軸を支持不能になると、第一の転がり軸受及び第二の転がり軸受は、その回転軸を支持する。第一の転がり軸受は、回転軸を径方向に支持し、第二の転がり軸受は、回転軸を径方向及び軸方向に支持する。第一の転がり軸受は、単列の第一の転がり軸受である。 The turbo molecular pump disclosed in Patent Document 1 includes, as a touchdown bearing, a first rolling bearing that can support the upper part of the rotating shaft, and a second rolling shaft that can support the lower part of the rotating shaft. In a normal operating state in which the magnetic bearing is functioning, the first rolling bearing and the second rolling bearing are in a non-contact state with the rotating shaft. When the magnetic bearing becomes unable to support the rotating shaft due to a malfunction, the first rolling bearing and the second rolling bearing support the rotating shaft. The first rolling bearing supports the rotating shaft in the radial direction, and the second rolling bearing supports the rotating shaft in the radial and axial directions. The first rolling bearing is a single row first rolling bearing.
　回転軸の重量が大きくなると、第一の転がり軸受は、回転軸から大きな径方向の荷重を受ける。第一の転がり軸受は、転動体である玉の径を大きくすることによって、負荷容量を大きくすることができる。しかし、この場合、第一の転がり軸受は、軸方向及び径方向に体積が大きくなり、その結果、ターボ分子ポンプのハウジングは、大型化する。別の手段として、図１０に示すように、第一の転がり軸受９０は、一つの内輪９１と、一つの外輪９８と、第一列Ｌ１の複数の転動体９５と、第二列Ｌ２の複数の転動体９２と、を備える。内輪９１は、第一列Ｌ１の内輪軌道溝９６と第二列Ｌ２の内輪軌道溝９３とを有する。外輪９８は、第一列Ｌ１の外輪軌道溝９７と第二列Ｌ２の外輪軌道溝９４とを有する。
第一列Ｌ１の軸受部は、第一列Ｌ１の内輪軌道溝９６と第一列Ｌ１の外輪軌道溝９７と第一列Ｌ１の複数の転動体９５とを備える。第二列Ｌ２の軸受部は、第二列Ｌ２の内輪軌道溝９３と第二列Ｌ２の外輪軌道溝９４と第二列Ｌ２の複数の転動体９２とを備える。第一列Ｌ１の軸受部と第二列Ｌ２の軸受部とを有する複列の転がり軸受にすることによって、負荷容量を大きくするが考えられる。ここで第一列Ｌ１の軸受部は、第二列Ｌ２の軸受部よりも、第二の転がり軸受から離れた位置にある。第一の転がり軸受９０は、複列の第一の転がり軸受である。 When the weight of the rotating shaft increases, the first rolling bearing receives a large radial load from the rotating shaft. The load capacity of the first rolling bearing can be increased by increasing the diameter of the balls, which are rolling elements. However, in this case, the volume of the first rolling bearing increases in the axial and radial directions, and as a result, the housing of the turbomolecular pump increases in size. As another means, as shown in FIG. 10, the first rolling bearing 90 includes one inner ring 91, one outer ring 98, a plurality of rolling elements 95 in the first row L1, and a plurality of rolling elements 95 in the second row L2. A rolling element 92 is provided. The inner ring 91 has an inner ring raceway groove 96 in a first row L1 and an inner ring raceway groove 93 in a second row L2. The outer ring 98 has an outer ring raceway groove 97 in a first row L1 and an outer ring raceway groove 94 in a second row L2.
The bearing portion of the first row L1 includes an inner raceway groove 96 of the first row L1, an outer raceway groove 97 of the first row L1, and a plurality of rolling elements 95 of the first row L1. The bearing portion of the second row L2 includes an inner raceway groove 93 of the second row L2, an outer raceway groove 94 of the second row L2, and a plurality of rolling elements 92 of the second row L2. It is conceivable to increase the load capacity by using a double row rolling bearing having a bearing portion in the first row L1 and a bearing portion in the second row L2. Here, the bearing portions of the first row L1 are located further away from the second rolling bearing than the bearing portions of the second row L2. The first rolling bearing 90 is a double-row first rolling bearing.
　磁気軸受による回転軸９９の支持が不能になると、その回転軸９９は、傾いて転がり軸受９０に接触する可能性がある。図１０において、回転軸９９は、内輪９１のうち、第一列Ｌ１の軸受部に、偏って接触している。内輪９１が第一列Ｌ１の内輪軌道溝９６と第二列Ｌ２の内輪軌道溝９３とを備えるため、第一列Ｌ１の内輪軌道溝９６と第二列Ｌ２の内輪軌道溝９３とは、同じ回転速度で回転する。このため、ラジアル荷重が大きい第一列Ｌ１の軸受部において、玉９５は、内輪軌道溝９６および外輪軌道溝９７を転がる。玉９５の転がりによって、内輪９１は外輪９８に対して回転する。一方、ラジアル荷重が第一列Ｌ１より小さい第二列Ｌ２側の軸受部において、玉９２は、内輪軌道溝９３及び外輪軌道溝９４に対してすべり、焼付きの原因となるおそれがある。 If the rotating shaft 99 cannot be supported by the magnetic bearing, the rotating shaft 99 may tilt and come into contact with the rolling bearing 90. In FIG. 10, the rotating shaft 99 is biased in contact with the bearing portion of the first row L1 of the inner ring 91. Since the inner ring 91 includes the inner ring raceway groove 96 of the first row L1 and the inner ring raceway groove 93 of the second row L2, the inner ring raceway groove 96 of the first row L1 and the inner ring raceway groove 93 of the second row L2 are the same. Rotate at rotational speed. Therefore, the balls 95 roll in the inner ring raceway groove 96 and the outer ring raceway groove 97 in the bearing portion of the first row L1 where the radial load is large. The rolling of the balls 95 causes the inner ring 91 to rotate relative to the outer ring 98. On the other hand, in the bearing portion on the second row L2 side where the radial load is smaller than that of the first row L1, the balls 92 may slide against the inner ring raceway groove 93 and the outer ring raceway groove 94, causing seizure.
　そこで、本開示は、回転軸が傾いて接触した場合であっても、玉と軌道溝との間のすべりを抑制することが可能となる複列深溝玉軸受を提供すること、及び、そのような複列深溝玉軸受を備える磁気軸受装置を提供することを目的とする。 Therefore, the present disclosure provides a double-row deep groove ball bearing that can suppress slippage between the balls and raceway grooves even when the rotating shafts come into contact with each other at an angle. An object of the present invention is to provide a magnetic bearing device including a double-row deep groove ball bearing.
　本開示の複列深溝玉軸受は、
　内周に第一の外輪軌道溝及び第二の外輪軌道溝が設けられている外輪と、
　外周に第一の内輪軌道溝が設けられている第一の内輪と、
　外周に第二の内輪軌道溝が設けられている第二の内輪と、
　前記第一の内輪軌道溝と前記第一の外輪軌道溝との間に設けられている複数の第一の玉と、
　前記第二の内輪軌道溝と前記第二の外輪軌道溝との間に設けられている複数の第二の玉と、
　を備え、
　前記外輪は、前記第一の外輪軌道溝が設けられている第一部分と、前記第一部分と一体であり前記第二の外輪軌道溝が設けられている第二部分と、を有し、
　前記第一の内輪と前記第二の内輪とは別体である。 The double row deep groove ball bearing of the present disclosure includes:
an outer ring having a first outer ring raceway groove and a second outer ring raceway groove on the inner periphery;
a first inner ring having a first inner ring raceway groove on its outer periphery;
a second inner ring having a second inner ring raceway groove on its outer periphery;
a plurality of first balls provided between the first inner raceway groove and the first outer raceway groove;
a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove;
Equipped with
The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove,
The first inner ring and the second inner ring are separate bodies.
　本開示の磁気軸受装置は、
　ハウジングと、
　前記ハウジング内に設けられている回転軸と、
　前記回転軸を支持可能である第一の転がり軸受と、
　前記回転軸を支持可能である第二の転がり軸受と、
　前記回転軸を径方向に支持可能であるラジアル磁気軸受と、
　前記回転軸を軸方向に支持可能であるアキシアル磁気軸受と、
　を備え、
　前記第一の転がり軸受は、前記回転軸の重心位置よりも、前記回転軸の軸方向の第一の側に設けられていて、前記第二の転がり軸受は、前記第一の転がり軸受よりも、前記回転軸の軸方向の第二の側に設けられていて、
　前記第一の転がり軸受は、
　　内周に第一の外輪軌道溝及び第二の外輪軌道溝が設けられ前記ハウジングに固定される第一外輪と、
　　外周に第一の内輪軌道溝が設けられている第一の内輪と、
　　外周に第二の内輪軌道溝が設けられている第二の内輪と、
　　前記第一の内輪軌道溝と前記第一の外輪軌道溝との間に設けられている複数の第一の玉と、
　　前記第二の内輪軌道溝と前記第二の外輪軌道溝との間に設けられている複数の第二の玉と、
　を備え、
　前記外輪は、前記第一の外輪軌道溝が設けられている第一部分と、前記第一部分と一体であり前記第二の外輪軌道溝が設けられている第二部分と、を有し、
　前記第一の内輪と前記第二の内輪とは別体であり、
　前記回転軸が前記ラジアル磁気軸受及び前記アキシアル磁気軸受によって支持されて回転している状態で、前記第一の内輪及び前記第二の内輪は、前記回転軸と非接触であり、前記ラジアル磁気軸受が前記回転軸を支持不能になると、前記第一の転がり軸受は、前記回転軸を径方向に支持する。 The magnetic bearing device of the present disclosure includes:
housing and
a rotating shaft provided within the housing;
a first rolling bearing capable of supporting the rotating shaft;
a second rolling bearing capable of supporting the rotating shaft;
a radial magnetic bearing capable of supporting the rotating shaft in a radial direction;
an axial magnetic bearing capable of supporting the rotating shaft in the axial direction;
Equipped with
The first rolling bearing is provided on a first side in the axial direction of the rotating shaft with respect to the center of gravity of the rotating shaft, and the second rolling bearing is provided on a first side of the rotating shaft with respect to the center of gravity of the rotating shaft. , provided on a second axial side of the rotating shaft,
The first rolling bearing is
a first outer ring that is fixed to the housing and has a first outer ring raceway groove and a second outer ring raceway groove on its inner periphery;
a first inner ring having a first inner ring raceway groove on its outer periphery;
a second inner ring having a second inner ring raceway groove on its outer periphery;
a plurality of first balls provided between the first inner raceway groove and the first outer raceway groove;
a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove;
Equipped with
The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove,
The first inner ring and the second inner ring are separate bodies,
While the rotating shaft is rotating while being supported by the radial magnetic bearing and the axial magnetic bearing, the first inner ring and the second inner ring are not in contact with the rotating shaft, and the radial magnetic bearing becomes unable to support the rotating shaft, the first rolling bearing supports the rotating shaft in the radial direction.
　本開示の複列深溝玉軸受によれば、回転軸が傾いた場合であっても、玉と軌道溝との間のすべりを抑制することが可能となる。
　本開示の磁気軸受装置によれば、回転軸が傾いた場合であっても、玉と軌道溝との間のすべりを抑制することが可能となる。 According to the double-row deep groove ball bearing of the present disclosure, even if the rotating shaft is tilted, it is possible to suppress slippage between the balls and the raceway grooves.
According to the magnetic bearing device of the present disclosure, even if the rotating shaft is tilted, it is possible to suppress slippage between the balls and the raceway grooves.
図１は、磁気軸受装置の一例を示す断面図である。FIG. 1 is a sectional view showing an example of a magnetic bearing device. 図２は、第一の転がり軸受の断面図である。FIG. 2 is a cross-sectional view of the first rolling bearing. 図３は、第一の転がり軸受の他の形態を示す断面図である。FIG. 3 is a sectional view showing another form of the first rolling bearing. 図４は、第一の転がり軸受のさらに別の形態を示す断面図である。FIG. 4 is a sectional view showing still another form of the first rolling bearing. 図５は、図２に示す第一の転がり軸受のさらに別の変形例を示す断面図である。FIG. 5 is a sectional view showing still another modification of the first rolling bearing shown in FIG. 2. FIG. 図６は、図３に示す第一の転がり軸受の変形例を示す断面図である。FIG. 6 is a sectional view showing a modification of the first rolling bearing shown in FIG. 3. FIG. 図７は、図３に示す第一の転がり軸受のさらに別の変形例を示す断面図である。FIG. 7 is a sectional view showing still another modification of the first rolling bearing shown in FIG. 3. 図８は、図４に示す第一の転がり軸受の変形例を示す断面図である。FIG. 8 is a sectional view showing a modification of the first rolling bearing shown in FIG. 4. 図９は、図４に示す第一の転がり軸受のさらに別の変形例を示す断面図である。FIG. 9 is a sectional view showing still another modification of the first rolling bearing shown in FIG. 4. 図１０は、従来の第一の転がり軸受の断面図である。FIG. 10 is a sectional view of a first conventional rolling bearing.
＜本開示の発明の実施形態の概要＞
　以下、本開示の発明の実施形態の概要を列記して説明する。 <Summary of embodiments of the disclosed invention>
Hereinafter, an outline of the embodiments of the invention of the present disclosure will be listed and explained.
　（１）本開示の複列深溝玉軸受は、
　内周に第一の外輪軌道溝及び第二の外輪軌道溝が設けられている外輪と、
　外周に第一の内輪軌道溝が設けられている第一の内輪と、
　外周に第二の内輪軌道溝が設けられている第二の内輪と、
　前記第一の内輪軌道溝と前記第一の外輪軌道溝との間に設けられている複数の第一の玉と、
　前記第二の内輪軌道溝と前記第二の外輪軌道溝との間に設けられている複数の第二の玉と、
　を備え、
　前記外輪は、前記第一の外輪軌道溝が設けられている第一部分と、前記第一部分と一体であり前記第二の外輪軌道溝が設けられている第二部分と、を有し、
　前記第一の内輪と前記第二の内輪とは別体である。 (1) The double row deep groove ball bearing of the present disclosure includes:
an outer ring having a first outer ring raceway groove and a second outer ring raceway groove on the inner periphery;
a first inner ring having a first inner ring raceway groove on its outer periphery;
a second inner ring having a second inner ring raceway groove on its outer periphery;
a plurality of first balls provided between the first inner ring raceway groove and the first outer ring raceway groove;
a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove;
Equipped with
The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove,
The first inner ring and the second inner ring are separate bodies.
　本開示の複列深溝玉軸受によれば、第一の内輪は第二の内輪との関係で独立して回転可能であり、第二の内輪は第一の内輪との関係で独立して回転可能となる。第一の内輪と第二の内輪との間に、回転（回転速度）の自由度が得られる。このため、傾く回転軸が第一の内輪に偏って接触しても、第二の内輪及び外輪と第二の玉との間のすべりが抑制される。 According to the double row deep groove ball bearing of the present disclosure, the first inner ring can rotate independently in relation to the second inner ring, and the second inner ring can rotate independently in relation to the first inner ring. It becomes possible. A degree of freedom in rotation (rotational speed) is obtained between the first inner ring and the second inner ring. For this reason, even if the tilting rotating shaft contacts the first inner ring unevenly, slippage between the second inner ring and outer ring and the second ball is suppressed.
　（２）好ましくは、前記第一の内輪と前記第二の内輪との間に、軸方向について隙間が設けられている。前記構成により、第一の内輪及び第二の内輪のうちの一方又は双方が変位しても、第一の内輪及び第二の内輪それぞれは独立して回転可能である。 (2) Preferably, a gap is provided between the first inner ring and the second inner ring in the axial direction. With the above configuration, even if one or both of the first inner ring and the second inner ring is displaced, each of the first inner ring and the second inner ring can rotate independently.
　（３）本開示の磁気軸受装置は、
　ハウジングと、
　前記ハウジング内に設けられている回転軸と、
　前記回転軸を支持可能である第一の転がり軸受と、
　前記回転軸を支持可能である第二の転がり軸受と、
　前記回転軸を径方向に支持可能であるラジアル磁気軸受と、
　前記回転軸を軸方向に支持可能であるアキシアル磁気軸受と、
　を備え、
　前記第一の転がり軸受は、前記回転軸の重心位置よりも、前記回転軸の軸方向の第一の側に設けられていて、前記第二の転がり軸受は、前記第一の転がり軸受よりも、前記回転軸の軸方向の第二の側に設けられていて、
　前記第一の転がり軸受は、
　　内周に第一の外輪軌道溝及び第二の外輪軌道溝が設けられ前記ハウジングに固定される第一外輪と、
　　外周に第一の内輪軌道溝が設けられている第一の内輪と、
　　外周に第二の内輪軌道溝が設けられている第二の内輪と、
　　前記第一の内輪軌道溝と前記第一の外輪軌道溝との間に設けられている複数の第一の玉と、
　　前記第二の内輪軌道溝と前記第二の外輪軌道溝との間に設けられている複数の第二の玉と、
　を備え、
　前記外輪は、前記第一の外輪軌道溝が設けられている第一部分と、前記第一部分と一体であり前記第二の外輪軌道溝が設けられている第二部分と、を有し、
　前記第一の内輪と前記第二の内輪とは別体であり、
　前記回転軸が前記ラジアル磁気軸受及び前記アキシアル磁気軸受によって支持されて回転している状態で、前記第一の内輪及び前記第二の内輪は、前記回転軸と非接触であり、前記ラジアル磁気軸受が前記回転軸を支持不能になると、前記第一の転がり軸受は、前記回転軸を径方向に支持する。 (3) The magnetic bearing device of the present disclosure includes:
housing and
a rotating shaft provided within the housing;
a first rolling bearing capable of supporting the rotating shaft;
a second rolling bearing capable of supporting the rotating shaft;
a radial magnetic bearing capable of supporting the rotating shaft in a radial direction;
an axial magnetic bearing capable of supporting the rotating shaft in the axial direction;
Equipped with
The first rolling bearing is provided on a first side in the axial direction of the rotating shaft with respect to the center of gravity of the rotating shaft, and the second rolling bearing is provided on a first side of the rotating shaft with respect to the center of gravity of the rotating shaft. , provided on a second axial side of the rotating shaft,
The first rolling bearing is
a first outer ring that is fixed to the housing and has a first outer ring raceway groove and a second outer ring raceway groove on its inner periphery;
a first inner ring having a first inner ring raceway groove on its outer periphery;
a second inner ring having a second inner ring raceway groove on its outer periphery;
a plurality of first balls provided between the first inner raceway groove and the first outer raceway groove;
a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove;
Equipped with
The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove,
The first inner ring and the second inner ring are separate bodies,
While the rotating shaft is rotating while being supported by the radial magnetic bearing and the axial magnetic bearing, the first inner ring and the second inner ring are not in contact with the rotating shaft, and the radial magnetic bearing becomes unable to support the rotating shaft, the first rolling bearing supports the rotating shaft in the radial direction.
　本開示の磁気軸受装置によれば、ラジアル磁気軸受による回転軸の支持が不能になると、第一の転がり軸受は、回転軸を径方向に支持する。その際、第一の内輪は第二の内輪との関係で独立して回転可能である。第一の内輪と第二の内輪との間に、回転（回転速度）の自由度が得られる。このため、傾く回転軸が第一の内輪に偏って接触しても、第二の内輪及び外輪と第二の玉との間のすべりが抑制される。 According to the magnetic bearing device of the present disclosure, when the radial magnetic bearing becomes unable to support the rotating shaft, the first rolling bearing supports the rotating shaft in the radial direction. In this case, the first inner ring can rotate independently in relation to the second inner ring. A degree of freedom in rotation (rotational speed) is obtained between the first inner ring and the second inner ring. For this reason, even if the tilting rotating shaft contacts the first inner ring unevenly, slippage between the second inner ring and outer ring and the second ball is suppressed.
　（４）好ましくは、
　前記第一の転がり軸受は総玉軸受であり、
　前記第一の内輪は前記第二の内輪よりも軸方向の第一の側に設けられていて、
　前記外輪の内周に、前記第一の側の外輪側面と前記第一の外輪軌道溝とをつなぐ前記第一の玉のための入れ溝が設けられていて、
　前記第一の内輪の外周に、前記第一の側の内輪側面と前記第一の内輪軌道溝とをつなぐ前記第一の玉のための入れ溝が設けられている。
　前記構成により、第一の転がり軸受の組み立てが容易となる。 (4) Preferably,
The first rolling bearing is a full ball bearing,
The first inner ring is provided on a first side in the axial direction than the second inner ring,
An insertion groove for the first ball connecting the first outer ring side surface and the first outer ring raceway groove is provided on the inner periphery of the outer ring,
An insertion groove for the first ball is provided on the outer periphery of the first inner ring, which connects the inner ring side surface on the first side and the first inner ring raceway groove.
The above configuration facilitates assembly of the first rolling bearing.
＜本開示の発明の実施形態の詳細＞
　以下、本開示の発明の実施形態を説明する。
〔磁気軸受装置の全体構成〕
　図１は、磁気軸受装置の一例を示す断面図である。図１に示す磁気軸受装置１０は、ターボ分子ポンプに用いられる。磁気軸受装置１０は、ハウジング１２、回転軸１１、第一のラジアル磁気軸受１３ａ、第二のラジアル磁気軸受１３ｂ、第一のアキシアル磁気軸受１４ａ、第二のアキシアル磁気軸受１４ｂ、モータ１５、第一の転がり軸受１６、及び、第二の転がり軸受１７を備える。 <Details of embodiments of the disclosed invention>
Embodiments of the disclosed invention will be described below.
[Overall configuration of magnetic bearing device]
FIG. 1 is a sectional view showing an example of a magnetic bearing device. A magnetic bearing device 10 shown in FIG. 1 is used for a turbo molecular pump. The magnetic bearing device 10 includes a housing 12, a rotating shaft 11, a first radial magnetic bearing 13a, a second radial magnetic bearing 13b, a first axial magnetic bearing 14a, a second axial magnetic bearing 14b, a motor 15, and a first radial magnetic bearing 13b. A rolling bearing 16 and a second rolling bearing 17 are provided.
　本開示における方向について説明する。磁気軸受装置１０は、回転軸１１を設計中心軸Ｃ周りに回転させるように支持する。その設計回転中心軸Ｃに沿った方向、及び、その設計回転中心軸Ｃに平行な方向は、「軸方向」である。設計回転中心軸Ｃに直交する方向は、「径方向」である。設計回転中心軸Ｃを中心とする円に沿った方向は、「周方向」である。図１に示す形態は、軸方向が鉛直上下方向と一致しており、「上」は、軸方向の第一の側であり、「下」は、軸方向の第二の側である。設計回転中心軸Ｃは、単に「中心軸Ｃ」と称する。 The direction of the present disclosure will be explained. The magnetic bearing device 10 supports the rotating shaft 11 so as to rotate around the designed central axis C. The direction along the designed rotational center axis C and the direction parallel to the designed rotational center axis C are "axial directions." The direction perpendicular to the design rotation center axis C is the "radial direction." The direction along the circle centered on the designed rotation center axis C is the "circumferential direction." In the form shown in FIG. 1, the axial direction coincides with the vertical vertical direction, and the "upper" is the first side in the axial direction, and the "lower" is the second side in the axial direction. The designed rotation center axis C is simply referred to as the "center axis C."
　ハウジング１２は、回転軸１１、ラジアル磁気軸受１３ａ，１３ｂ、アキシアル磁気軸受１４ａ，１４ｂ、モータ１５、第一の転がり軸受１６、及び、第二の転がり軸受１７を収容する。ハウジング１２は、吸気口６１と排気口６２とを備える。ハウジング１２は、複数の固定翼６３を有する。
　モータ１５は、回転軸１１を回転させる。モータ１５は、回転軸１１の軸方向の中央部に対応する位置に設けられている。 The housing 12 accommodates the rotating shaft 11, radial magnetic bearings 13a, 13b, axial magnetic bearings 14a, 14b, motor 15, first rolling bearing 16, and second rolling bearing 17. The housing 12 includes an intake port 61 and an exhaust port 62. The housing 12 has a plurality of fixed wings 63.
Motor 15 rotates rotating shaft 11 . The motor 15 is provided at a position corresponding to the axial center of the rotating shaft 11 .
　回転軸１１は、ハウジング１２内に設けられている。回転軸１１は、軸本体６６と、軸本体６６と一体回転する回転ブロック６４とを有する。回転ブロック６４は、複数の回転翼６５を有する。回転翼６５と固定翼６３とは軸方向に交互に並んで配置されている。回転軸１１は、その下部に円板部６７を有する。回転軸１１は、ハウジング１２内で中心軸Ｃを中心として回転可能となる。そのために、ラジアル磁気軸受１３ａ，１３ｂ及びアキシアル磁気軸受１４ａ，１４ｂが、ハウジング１２に設けられている。 The rotating shaft 11 is provided within the housing 12. The rotating shaft 11 includes a shaft main body 66 and a rotating block 64 that rotates integrally with the shaft main body 66. The rotating block 64 has a plurality of rotary blades 65. The rotary blades 65 and the fixed blades 63 are arranged alternately in the axial direction. The rotating shaft 11 has a disk portion 67 at its lower part. The rotating shaft 11 is rotatable around the central axis C within the housing 12. For this purpose, the housing 12 is provided with radial magnetic bearings 13a, 13b and axial magnetic bearings 14a, 14b.
　第一のラジアル磁気軸受１３ａと、第二のラジアル磁気軸受１３ｂとは、軸方向に離れて設けられている。第一のラジアル磁気軸受１３ａは、モータ１５よりも上に設けられている。第二のラジアル磁気軸受１３ｂは、モータ１５よりも下に設けられている。これらラジアル磁気軸受１３ａ，１３ｂは、回転軸１１を非接触で支持可能である。ラジアル磁気軸受１３ａ，１３ｂは、磁力によって回転軸１１を径方向について支持する機能を有している。ラジアル磁気軸受１３ａ，１３ｂは、従来、知られている構成が採用される。 The first radial magnetic bearing 13a and the second radial magnetic bearing 13b are provided apart in the axial direction. The first radial magnetic bearing 13a is provided above the motor 15. The second radial magnetic bearing 13b is provided below the motor 15. These radial magnetic bearings 13a and 13b can support the rotating shaft 11 without contact. The radial magnetic bearings 13a and 13b have the function of supporting the rotating shaft 11 in the radial direction using magnetic force. The radial magnetic bearings 13a and 13b employ a conventionally known configuration.
　第一のアキシアル磁気軸受１４ａと、第二のアキシアル磁気軸受１４ｂとは、軸方向に離れて設けられている。第一のアキシアル磁気軸受１４ａは、円板部６７の上に設けられている。第二のアキシアル磁気軸受１４ｂは、円板部６７の下に設けられている。これらアキシアル磁気軸受１４ａ，１４ｂは、回転軸１１を非接触で支持可能である。アキシアル磁気軸受１４ａ，１４ｂは、磁力によって回転軸１１を軸方向について支持する機能を有している。アキシアル磁気軸受１４ａ，１４ｂは、従来、知られている構成が採用される。 The first axial magnetic bearing 14a and the second axial magnetic bearing 14b are provided apart in the axial direction. The first axial magnetic bearing 14a is provided on the disk portion 67. The second axial magnetic bearing 14b is provided below the disk portion 67. These axial magnetic bearings 14a and 14b can support the rotating shaft 11 without contact. The axial magnetic bearings 14a and 14b have a function of supporting the rotating shaft 11 in the axial direction by magnetic force. The axial magnetic bearings 14a, 14b employ a conventionally known configuration.
　第一の転がり軸受１６は、回転軸１１の重心位置Ｇよりも上に設けられている。第二の転がり軸受１７は、第一の転がり軸受１６よりも下であって、回転軸１１の重心位置Ｇよりも下に設けられている。
　第一の転がり軸受１６及び第二の転がり軸受１７について、以下に説明する。 The first rolling bearing 16 is provided above the center of gravity G of the rotating shaft 11. The second rolling bearing 17 is provided below the first rolling bearing 16 and below the center of gravity G of the rotating shaft 11.
The first rolling bearing 16 and the second rolling bearing 17 will be explained below.
〔第一の転がり軸受１６について〕
　図２は、第一の転がり軸受１６の断面図である。図２は、中心軸Ｃを含む面における断面図である。第一の転がり軸受１６は、複列深溝玉軸受であり、回転軸１１を径方向について支持可能である。図２では、回転軸１１を二点鎖線で示す。第一の転がり軸受１６は、中心軸Ｃを中心としてハウジング１２に取り付けられている。 [About the first rolling bearing 16]
FIG. 2 is a cross-sectional view of the first rolling bearing 16. FIG. 2 is a sectional view taken along a plane including the central axis C. The first rolling bearing 16 is a double-row deep groove ball bearing, and is capable of supporting the rotating shaft 11 in the radial direction. In FIG. 2, the rotating shaft 11 is indicated by a chain double-dashed line. The first rolling bearing 16 is attached to the housing 12 around the central axis C.
　第一の転がり軸受１６は、一つの外輪２０と、一つの第一の内輪２１と、一つの第二の内輪２２と、複数の第一の玉２３と、複数の第二の玉２４とを有する。第一の内輪２１と第二の内輪２２とは別体であり分離して設けられている。これに対して、外輪２０は、第一の内輪２１及び第二の内輪２２のために共用される一つの軌道輪である。 The first rolling bearing 16 includes one outer ring 20, one first inner ring 21, one second inner ring 22, a plurality of first balls 23, and a plurality of second balls 24. have The first inner ring 21 and the second inner ring 22 are separate bodies and are provided separately. On the other hand, the outer ring 20 is one bearing ring that is shared by the first inner ring 21 and the second inner ring 22.
　外輪２０は、ハウジング１２の一部の内周面７０に固定されている。外輪２０は円筒状の部材である。外輪２０の外周面は軸受外径面である。外輪２０の内周に第一の外輪軌道溝２６及び第二の外輪軌道溝２７が設けられている。外輪２０は、第一部分２０ａと、第一部分２０ａと一体である第二部分２０ｂとを有する。第一の外輪軌道溝２６は、第一部分２０ａに設けられている。第二の外輪軌道溝２７は、第二部分２０ｂに設けられている。第一部分２０ａは、一つの円筒状の部材の一部であり、第二部分２０ｂは、前記一つの円筒状の部材の残りの他部である。 The outer ring 20 is fixed to a part of the inner peripheral surface 70 of the housing 12. The outer ring 20 is a cylindrical member. The outer peripheral surface of the outer ring 20 is a bearing outer diameter surface. A first outer ring raceway groove 26 and a second outer ring raceway groove 27 are provided on the inner periphery of the outer ring 20 . The outer ring 20 has a first portion 20a and a second portion 20b that is integral with the first portion 20a. The first outer ring raceway groove 26 is provided in the first portion 20a. The second outer ring raceway groove 27 is provided in the second portion 20b. The first portion 20a is a part of one cylindrical member, and the second portion 20b is the remaining part of the one cylindrical member.
　第一部分２０ａは、第一の転がり軸受１６の第一列Ｌ１の外輪として機能する。第二部分２０ｂは、第一の転がり軸受１６の第二列Ｌ２の外輪として機能する。第一部分２０ａは第二部分２０ｂよりも上に位置する。その結果、第一の外輪軌道溝２６は、第二の外輪軌道溝２７よりも上に位置する。 The first portion 20a functions as an outer ring of the first row L1 of the first rolling bearing 16. The second portion 20b functions as an outer ring of the second row L2 of the first rolling bearing 16. The first portion 20a is located above the second portion 20b. As a result, the first outer ring raceway groove 26 is located above the second outer ring raceway groove 27.
　外輪２０は、第一の外輪軌道溝２６の上側に肩３６ａを有する。外輪２０は、第二の外輪軌道溝２７の下側に肩３６ｂを有する。外輪２０は、第一の外輪軌道溝２６と第二の外輪軌道溝２７との間に、中間の肩３０を有する。中間の肩３０は、周方向に連続して設けられている。中間の肩３０の内周面は、軌道溝２６，２７よりも内径が小さい。 The outer ring 20 has a shoulder 36a above the first outer ring raceway groove 26. The outer ring 20 has a shoulder 36b below the second outer ring raceway groove 27. The outer ring 20 has an intermediate shoulder 30 between the first outer ring raceway groove 26 and the second outer ring raceway groove 27 . The intermediate shoulder 30 is provided continuously in the circumferential direction. The inner peripheral surface of the intermediate shoulder 30 has a smaller inner diameter than the raceway grooves 26 and 27.
　第一の内輪２１は、外輪２０よりも軸方向に短い円筒状の部材である。第一の内輪軌道溝２８は、第一の内輪２１の外周に設けられている。第一の内輪２１は、第一の内輪軌道溝２８の軸方向の両側（上側及び下側）それぞれに、肩３７を有する。第一の内輪２１は、その内周に、軸方向の中央に位置する第一の軸受内径面３１と、第一の軸受内径面３１の上側及び下側それぞれに設けられている第一の面取り３２とを有する。第一の軸受内径面３１は、中心軸Ｃを中心とする円筒面である。第一の内輪２１の内径は、回転軸１１における支持部の外径よりも大きい。 The first inner ring 21 is a cylindrical member that is shorter in the axial direction than the outer ring 20. The first inner ring raceway groove 28 is provided on the outer periphery of the first inner ring 21 . The first inner ring 21 has shoulders 37 on both sides (upper and lower sides) of the first inner ring raceway groove 28 in the axial direction. The first inner ring 21 has a first bearing inner diameter surface 31 located at the center in the axial direction, and a first chamfer provided on the upper and lower sides of the first bearing inner diameter surface 31 on its inner circumference. 32. The first bearing inner diameter surface 31 is a cylindrical surface centered on the central axis C. The inner diameter of the first inner ring 21 is larger than the outer diameter of the support portion of the rotating shaft 11 .
　第二の内輪２２は、外輪２０よりも軸方向に短い円筒状の部材である。第二の内輪軌道溝２９は、第二の内輪２２の外周に設けられている。第二の内輪２２は、第二の内輪軌道溝２９の軸方向の両側（上側及び下側）それぞれに、肩３８を有する。第二の内輪２２は、その内周に、軸方向の中央に位置する第二の軸受内径面３３と、第二の軸受内径面３３の上側及び下側それぞれに設けられている第二の面取り３４とを有する。第二の軸受内径面３３は、中心軸Ｃを中心とする円筒面である。第二の内輪２２の内径は、回転軸１１における支持部の外径よりも大きい。 The second inner ring 22 is a cylindrical member that is shorter in the axial direction than the outer ring 20. The second inner ring raceway groove 29 is provided on the outer periphery of the second inner ring 22. The second inner ring 22 has shoulders 38 on both sides (upper and lower sides) of the second inner ring raceway groove 29 in the axial direction. The second inner ring 22 has, on its inner periphery, a second bearing inner diameter surface 33 located at the center in the axial direction, and second chamfers provided on the upper and lower sides of the second bearing inner diameter surface 33, respectively. 34. The second bearing inner diameter surface 33 is a cylindrical surface centered on the central axis C. The inner diameter of the second inner ring 22 is larger than the outer diameter of the support portion of the rotating shaft 11 .
　第一の内輪２１の内径は、第二の内輪２２の内径と同じである。図２に示す形態において、第一の軸受内径面３１の直径は、第一の内輪２１の内径であり、第二の軸受内径面３３の直径は、第二の内輪２２の内径である。よって、第一の軸受内径面３１の直径は、第二の軸受内径面３３の直径と同じである。 The inner diameter of the first inner ring 21 is the same as the inner diameter of the second inner ring 22. In the form shown in FIG. 2, the diameter of the first bearing inner diameter surface 31 is the inner diameter of the first inner ring 21, and the diameter of the second bearing inner diameter surface 33 is the inner diameter of the second inner ring 22. Therefore, the diameter of the first bearing inner diameter surface 31 is the same as the diameter of the second bearing inner diameter surface 33.
　第一の内輪２１は第二の内輪２２よりも上に位置する。第一の内輪２１は、第一の転がり軸受１６の第一列Ｌ１の内輪となる。第二の内輪２２は、第一の転がり軸受１６の第二列Ｌ２の内輪となる。隙間Ｅが、第一の内輪２１と第二の内輪２２との間に、軸方向に設けられている。隙間Ｅは、第一の内輪２１と第二の内輪２２とが軸方向に変位しても、相互で接触不能とする軸方向の寸法に設定されている。 The first inner ring 21 is located above the second inner ring 22. The first inner ring 21 becomes the inner ring of the first row L1 of the first rolling bearing 16. The second inner ring 22 becomes the inner ring of the second row L2 of the first rolling bearing 16. A gap E is provided between the first inner ring 21 and the second inner ring 22 in the axial direction. The gap E is set to an axial dimension that prevents the first inner ring 21 and the second inner ring 22 from coming into contact with each other even if the first inner ring 21 and the second inner ring 22 are displaced in the axial direction.
　複数の第一の玉２３は、第一の内輪軌道溝２８と第一の外輪軌道溝２６との間に設けられている。複数の第二の玉２４は、第二の内輪軌道溝２９と第二の外輪軌道溝２７との間に設けられている。第一の玉２３が、第一の転がり軸受１６の第一列Ｌ１の転動体となる。第二の玉２４が、第一の転がり軸受１６の第二列Ｌ２の転動体となる。第一の外輪軌道溝２６、第二の外輪軌道溝２７、第一の内輪軌道溝２８、及び、第二の内輪軌道溝２９それぞれは、中心軸Ｃを含む断面において、円弧形状を有する。 The plurality of first balls 23 are provided between the first inner ring raceway groove 28 and the first outer ring raceway groove 26. The plurality of second balls 24 are provided between the second inner ring raceway groove 29 and the second outer ring raceway groove 27. The first balls 23 serve as rolling elements of the first row L1 of the first rolling bearing 16. The second balls 24 serve as rolling elements of the second row L2 of the first rolling bearing 16. Each of the first outer ring raceway groove 26, the second outer ring raceway groove 27, the first inner ring raceway groove 28, and the second inner ring raceway groove 29 has an arc shape in a cross section including the central axis C.
　第一列Ｌ１の軸受部は、外輪２０の第一部分２０ａ、第一の内輪２１、及び、複数の第一の玉２３によって構成される。第二列Ｌ２の軸受部は、外輪２０の第二部分２０ｂ、第二の内輪２２、及び、複数の第二の玉２４によって構成される。
　第一列Ｌ１の軸受部と、第二列Ｌ２の軸受部と、はそれぞれ深溝玉軸受である。
　複数の第一の玉２３を含む玉セットのピッチ径Ｄ１は、複数の第二の玉２４を含む玉セットのピッチ径Ｄ２と同じである。第一の玉２３の直径ｄ１は、第二の玉２４の直径ｄ２と同じである。 The bearing portion of the first row L1 is constituted by a first portion 20a of the outer ring 20, a first inner ring 21, and a plurality of first balls 23. The bearing portion of the second row L2 is constituted by the second portion 20b of the outer ring 20, the second inner ring 22, and the plurality of second balls 24.
The bearing portions in the first row L1 and the bearing portions in the second row L2 are each deep groove ball bearings.
The pitch diameter D1 of the ball set including the plurality of first balls 23 is the same as the pitch diameter D2 of the ball set including the plurality of second balls 24. The diameter d1 of the first ball 23 is the same as the diameter d2 of the second ball 24.
　外輪２０、第一の内輪２１、及び、第二の内輪２２は、例えば、高速度工具鋼、軸受鋼又はステンレス鋼により製造されている。第一の玉２３及び第二の玉２４は、高速度工具鋼、軸受鋼、ステンレス鋼又はセラミックスによって製造されている。皮膜が、第一の外輪軌道溝２６、第二の外輪軌道溝２７、第一の内輪軌道溝２８、及び、第二の内輪軌道溝２９のそれぞれの表面に形成されている。皮膜は、固体潤滑剤である。 The outer ring 20, the first inner ring 21, and the second inner ring 22 are made of, for example, high-speed tool steel, bearing steel, or stainless steel. The first ball 23 and the second ball 24 are manufactured from high speed tool steel, bearing steel, stainless steel, or ceramics. A coating is formed on each surface of the first outer ring raceway groove 26, the second outer ring raceway groove 27, the first inner ring raceway groove 28, and the second inner ring raceway groove 29. The film is a solid lubricant.
　第一の転がり軸受１６は、総玉軸受である。第一列Ｌ１の軸受部及び第二列Ｌ２の軸受部は、それぞれ保持器を備えていない。隣り合う第一の玉２３と第一の玉２３とは接触可能となる。隣り合う第二の玉２４と第二の玉２４とは接触可能となる。 The first rolling bearing 16 is a full ball bearing. The bearing portions of the first row L1 and the bearing portions of the second row L2 are each not provided with a retainer. Adjacent first balls 23 and first balls 23 can come into contact with each other. Adjacent second balls 24 can come into contact with each other.
〔第二の転がり軸受１７について〕
　図１に示すように、第二の転がり軸受１７は、回転軸１１の下部を支持可能である。第二の転がり軸受１７は、２つのアンギュラ玉軸受１８，１８により構成されている。第二の転がり軸受１７は、第一のアンギュラ玉軸受１８と第二のアンギュラ玉軸受１８とを正面配列で組み合わせている。第二の転がり軸受１７は、回転軸１１を径方向及び軸方向について支持可能である。 [About the second rolling bearing 17]
As shown in FIG. 1, the second rolling bearing 17 can support the lower part of the rotating shaft 11. The second rolling bearing 17 is composed of two angular ball bearings 18, 18. The second rolling bearing 17 is a combination of a first angular contact ball bearing 18 and a second angular contact ball bearing 18 in a front-on arrangement. The second rolling bearing 17 can support the rotating shaft 11 in the radial direction and the axial direction.
　第一のアンギュラ玉軸受１８は、第三の外輪３９と、第三の内輪４１と、複数の第三の玉４３とを備える。第三の外輪３９は、背面を上側に向けてハウジング１２に固定される。第三の外輪軌道溝４６は、第三の外輪３９の内周に設けられている。第三の内輪４１は、正面を上側に向けて配置される。第三の内輪軌道溝４８は、第三の内輪４１の外周に設けられている。複数の第三の玉４３は、第三の内輪軌道溝４８と第三の外輪軌道溝４６との間に設けられている。 The first angular contact ball bearing 18 includes a third outer ring 39, a third inner ring 41, and a plurality of third balls 43. The third outer ring 39 is fixed to the housing 12 with its back surface facing upward. The third outer ring raceway groove 46 is provided on the inner periphery of the third outer ring 39. The third inner ring 41 is arranged with its front facing upward. The third inner ring raceway groove 48 is provided on the outer periphery of the third inner ring 41. The plurality of third balls 43 are provided between the third inner ring raceway groove 48 and the third outer ring raceway groove 46.
　第二のアンギュラ玉軸受１８は、第四の外輪４０と、第四の内輪４２と、複数の第四の玉４４とを備える。第四の外輪４０は、正面を上側に向けてハウジング１２に固定される。第四の外輪軌道溝４７は、第四の外輪４０の内周に設けられている。第四の内輪４２は、背面を上方に向けて配置される。第四の内輪軌道溝４９は、第四の内輪４２の外周に設けられている。複数の第四の玉４４は、第四の内輪軌道溝４９と第四の外輪軌道溝４７との間に設けられている。 The second angular contact ball bearing 18 includes a fourth outer ring 40, a fourth inner ring 42, and a plurality of fourth balls 44. The fourth outer ring 40 is fixed to the housing 12 with the front facing upward. The fourth outer ring raceway groove 47 is provided on the inner periphery of the fourth outer ring 40. The fourth inner ring 42 is arranged with its back surface facing upward. The fourth inner ring raceway groove 49 is provided on the outer periphery of the fourth inner ring 42 . The plurality of fourth balls 44 are provided between the fourth inner ring raceway groove 49 and the fourth outer ring raceway groove 47.
　第三の外輪３９と第四の外輪４０とは、それぞれの正面が軸方向に接触した状態となって、ハウジング１２に固定されている。第三の内輪４１と第四の内輪４２とは、それぞれの背面が軸方向に接触した状態となって、設けられている。第三の内輪４１及び第四の内輪４２それぞれの内径は、回転軸１１における支持部の外径よりも大きい。 The third outer ring 39 and the fourth outer ring 40 are fixed to the housing 12 with their front surfaces in contact with each other in the axial direction. The third inner ring 41 and the fourth inner ring 42 are provided so that their respective back surfaces are in contact with each other in the axial direction. The inner diameter of each of the third inner ring 41 and the fourth inner ring 42 is larger than the outer diameter of the support portion of the rotating shaft 11.
　〔磁気軸受装置１０の機能について〕
　本実施形態（図１参照）の磁気軸受装置１０はターボ分子ポンプに用いられる。通常運転状態で、回転軸１１はラジアル磁気軸受１３ａ，１３ｂ及びアキシアル磁気軸受１４ａ，１４ｂによって支持されて回転する。通常運転状態において、回転軸１１は中心軸Ｃを中心として回転する。
　通常運転状態において、回転軸１１は、第一の転がり軸受１６との間に隙間が生じる。回転軸１１は、第二の転がり軸受１７との間に隙間が生じる。回転軸１１と第一の転がり軸受１６とは、非接触の状態にある。回転軸１１と第二の転がり軸受１７とは、非接触の状態にある。つまり、通常運転状態で、第一の転がり軸受１６の第一の内輪２１及び第二の内輪２２は、回転軸１１に接触しておらず、第二の転がり軸受１７の第三の内輪４１及び第四の内輪４２は、回転軸１１に接触していない。 [About the functions of the magnetic bearing device 10]
The magnetic bearing device 10 of this embodiment (see FIG. 1) is used for a turbo molecular pump. In normal operating conditions, the rotating shaft 11 rotates while being supported by radial magnetic bearings 13a, 13b and axial magnetic bearings 14a, 14b. In the normal operating state, the rotating shaft 11 rotates around the central axis C.
In a normal operating state, a gap is created between the rotating shaft 11 and the first rolling bearing 16. A gap is created between the rotating shaft 11 and the second rolling bearing 17. The rotating shaft 11 and the first rolling bearing 16 are in a non-contact state. The rotating shaft 11 and the second rolling bearing 17 are in a non-contact state. That is, in the normal operating state, the first inner ring 21 and the second inner ring 22 of the first rolling bearing 16 are not in contact with the rotating shaft 11, and the third inner ring 41 and the second inner ring of the second rolling bearing 17 are not in contact with the rotating shaft 11. The fourth inner ring 42 is not in contact with the rotating shaft 11.
　ラジアル磁気軸受１３ａ，１３ｂ及びアキシアル磁気軸受１４ａ，１４ｂのいずれか一つでも故障したり停電等により不具合が生じた非常運転状態において、回転軸１１は不安定となる。 In an emergency operating state in which any one of the radial magnetic bearings 13a, 13b and the axial magnetic bearings 14a, 14b fails or a malfunction occurs due to a power outage, etc., the rotating shaft 11 becomes unstable.
　非常運転状態になると、第一の転がり軸受１６は、回転軸１１を径方向に支持することが可能となる。特に、第一のラジアル磁気軸受１３ａ及び第二のラジアル磁気軸受１３ｂの少なくとも一方が、回転軸１１を支持不能になると、第一の転がり軸受１６は、回転軸１１を径方向に支持することが可能となる。つまり、回転軸１１が磁力によって支持されなくなると、第一の内輪２１及び第二の内輪２２の少なくとも一方は、回転軸１１と接触し、回転軸１１を径方向に支持することが可能となる。 In the emergency operating state, the first rolling bearing 16 is able to support the rotating shaft 11 in the radial direction. In particular, when at least one of the first radial magnetic bearing 13a and the second radial magnetic bearing 13b becomes unable to support the rotating shaft 11, the first rolling bearing 16 cannot support the rotating shaft 11 in the radial direction. It becomes possible. In other words, when the rotating shaft 11 is no longer supported by magnetic force, at least one of the first inner ring 21 and the second inner ring 22 comes into contact with the rotating shaft 11, and it becomes possible to support the rotating shaft 11 in the radial direction. .
　非常運転状態になると、第二の転がり軸受１７は、回転軸１１を径方向及び軸方向に支持することが可能となる。特に、ラジアル磁気軸受１３ａ，１３ｂ、アキシアル磁気軸受１４ａ，１４ｂの少なくとも一つが、回転軸１１を支持不能になると、第二の転がり軸受１７は、回転軸１１を径方向及び軸方向に支持することが可能となる。つまり、回転軸１１が磁力によって支持されなくなると、第三の内輪４１及び第四の内輪４２の少なくとも一方は、回転軸１１と接触し、第二の転がり軸受１７は、回転軸１１を径方向に支持することが可能となる。第三の内輪４１に、回転軸１１の大径部１１ａが軸方向に接触し、第二の転がり軸受１７は、回転軸１１を軸方向に支持することが可能となる。 In the emergency operating state, the second rolling bearing 17 is able to support the rotating shaft 11 in the radial and axial directions. In particular, when at least one of the radial magnetic bearings 13a, 13b and the axial magnetic bearings 14a, 14b becomes unable to support the rotating shaft 11, the second rolling bearing 17 supports the rotating shaft 11 in the radial and axial directions. becomes possible. That is, when the rotating shaft 11 is no longer supported by the magnetic force, at least one of the third inner ring 41 and the fourth inner ring 42 comes into contact with the rotating shaft 11, and the second rolling bearing 17 supports the rotating shaft 11 in the radial direction. It becomes possible to support the The large diameter portion 11a of the rotating shaft 11 comes into contact with the third inner ring 41 in the axial direction, and the second rolling bearing 17 can support the rotating shaft 11 in the axial direction.
　不安定となる回転軸１１がラジアル磁気軸受１３ａ，１３ｂに接触するよりも前に、その回転軸１１は、第一の転がり軸受１６及び第二の転がり軸受１７によって支持される。不安定となる回転軸１１がアキシアル磁気軸受１４ａ，１４ｂに接触するよりも前に、その回転軸１１は、第二の転がり軸受１７によって支持される。 Before the rotating shaft 11, which becomes unstable, comes into contact with the radial magnetic bearings 13a and 13b, the rotating shaft 11 is supported by the first rolling bearing 16 and the second rolling bearing 17. Before the rotating shaft 11 comes into contact with the axial magnetic bearings 14a, 14b, which becomes unstable, the rotating shaft 11 is supported by the second rolling bearing 17.
　以上より、第一の転がり軸受１６及び第二の転がり軸受１７は、タッチダウン軸受として機能する。また、回転軸１１の回転が停止している状態においても、回転軸１１は、第一の転がり軸受１６によって径方向に支持され、第二の転がり軸受１７によって径方向及び軸方向に支持される。 As described above, the first rolling bearing 16 and the second rolling bearing 17 function as touchdown bearings. Furthermore, even when the rotation of the rotating shaft 11 is stopped, the rotating shaft 11 is supported in the radial direction by the first rolling bearing 16 and in the radial and axial directions by the second rolling bearing 17. .
〔第一の転がり軸受１６の他の形態〕
　図２に示す第一の転がり軸受１６の場合、複数の第一の玉２３を含む玉セットのピッチ径Ｄ１は、複数の第二の玉２４を含む玉セットのピッチ径Ｄ２と同じである。第一の玉２３の直径ｄ１と、第二の玉２４の直径ｄ２とは、同じである。
　図３は、第一の転がり軸受１６の他の形態を示す断面図である。図３に示す第一の転がり軸受１６において、複数の第一の玉２３を含む玉セットのピッチ径Ｄ１は、複数の第二の玉２４を含む玉セットのピッチ径Ｄ２よりも大きい。
　図３に示す第一の転がり軸受１６の複数の第一の玉２３を含む玉セットのピッチ径Ｄ１と、複数の第二の玉２４を含む玉セットのピッチ径Ｄ２と、を除く構成は、図２に示す第一の転がり軸受１６の複数の第一の玉２３を含む玉セットのピッチ径Ｄ１と、複数の第二の玉２４を含む玉セットのピッチ径Ｄ２と、を除く構成と同じであり、その説明について、省略する。なお、図３に示す第一の転がり軸受１６の構成の符号は、図２に示す第一の転がり軸受１６の構成の符号と同じである。 [Other forms of first rolling bearing 16]
In the case of the first rolling bearing 16 shown in FIG. 2, the pitch diameter D1 of the ball set including the plurality of first balls 23 is the same as the pitch diameter D2 of the ball set including the plurality of second balls 24. The diameter d1 of the first ball 23 and the diameter d2 of the second ball 24 are the same.
FIG. 3 is a sectional view showing another form of the first rolling bearing 16. In the first rolling bearing 16 shown in FIG. 3, the pitch diameter D1 of the ball set including the plurality of first balls 23 is larger than the pitch diameter D2 of the ball set including the plurality of second balls 24.
The configuration of the first rolling bearing 16 shown in FIG. 3 except for the pitch diameter D1 of the ball set including the plurality of first balls 23 and the pitch diameter D2 of the ball set including the plurality of second balls 24 is as follows. The configuration is the same as that of the first rolling bearing 16 shown in FIG. 2 except for the pitch diameter D1 of the ball set including the plurality of first balls 23 and the pitch diameter D2 of the ball set including the plurality of second balls 24. , and its explanation will be omitted. Note that the reference numerals of the structure of the first rolling bearing 16 shown in FIG. 3 are the same as the reference numerals of the structure of the first rolling bearing 16 shown in FIG.
〔第一の転がり軸受１６のさらに別の形態〕
　図４は、第一の転がり軸受１６のさらに別の形態を示す断面図である。図４に示す第一の転がり軸受１６において、第一の玉２３の直径ｄ１が、第二の玉２４の直径ｄ２よりも大きい。
　図４に示す第一の転がり軸受１６の第一の玉２３の直径ｄ１と、第二の玉２４の直径ｄ２と、を除く構成は、図２に示す第一の転がり軸受１６の第一の玉２３の直径ｄ１と、第二の玉２４の直径ｄ２と、を除く構成と同じであり、その説明について、省略する。なお、図４に示す第一の転がり軸受１６の構成の符号は、図２に示す第一の転がり軸受１６の構成の符号と同じである。 [Yet another form of the first rolling bearing 16]
FIG. 4 is a sectional view showing still another form of the first rolling bearing 16. In the first rolling bearing 16 shown in FIG. 4, the diameter d1 of the first ball 23 is larger than the diameter d2 of the second ball 24.
The configuration excluding the diameter d1 of the first ball 23 and the diameter d2 of the second ball 24 of the first rolling bearing 16 shown in FIG. The configuration is the same except for the diameter d1 of the ball 23 and the diameter d2 of the second ball 24, and the explanation thereof will be omitted. Note that the reference numerals of the structure of the first rolling bearing 16 shown in FIG. 4 are the same as the reference numerals of the structure of the first rolling bearing 16 shown in FIG.
〔第一の転がり軸受１６の構成及び作用について〕
　以上に述べたように、前記各形態（図２、図３、図４）の第一の転がり軸受１６は、内周に第一の外輪軌道溝２６及び第二の外輪軌道溝２７が設けられている一つの外輪２０と、外周に第一の内輪軌道溝２８が設けられている一つの第一の内輪２１と、外周に第二の内輪軌道溝２９が設けられている一つの第二の内輪２２と、第一の内輪軌道溝２８と第一の外輪軌道溝２６との間に設けられている複数の第一の玉２３と、第二の内輪軌道溝２９と第二の外輪軌道溝２７との間に設けられている複数の第二の玉２４とを備える。外輪２０は、第一の外輪軌道溝２６が設けられている第一部分２０ａと、第二の外輪軌道溝２７が設けられている第二部分２０ｂとを有する。第一部分２０ａと第二部分２０ｂとは一体である。第一の内輪２１と第二の内輪２２とは別体である。 [About the structure and operation of the first rolling bearing 16]
As described above, the first rolling bearing 16 of each of the above embodiments (FIGS. 2, 3, and 4) is provided with the first outer ring raceway groove 26 and the second outer ring raceway groove 27 on the inner periphery. one first inner ring 21 having a first inner ring raceway groove 28 on its outer periphery; and one second inner ring 21 having a second inner ring raceway groove 29 on its outer periphery. The inner ring 22, the plurality of first balls 23 provided between the first inner ring raceway groove 28 and the first outer ring raceway groove 26, the second inner ring raceway groove 29 and the second outer ring raceway groove. 27, and a plurality of second balls 24 provided between the balls 27 and 27. The outer ring 20 has a first portion 20a in which a first outer ring raceway groove 26 is provided, and a second portion 20b in which a second outer ring raceway groove 27 is provided. The first portion 20a and the second portion 20b are integral. The first inner ring 21 and the second inner ring 22 are separate bodies.
　前記各形態の第一の転がり軸受１６によれば、第一の内輪２１は、第二の内輪２２に対して独立して、一つの外輪２０に対して回転可能であり、第二の内輪２２は第一の内輪２１に対して独立して、一つの外輪２０に対して回転可能となる。第一の内輪２１と第二の内輪２２とは、外輪２０に対して異なった回転速度で回転できる。このため、磁気軸受装置１０が非常運転状態になり、傾く回転軸１１が第一列Ｌ２側の第一の内輪２１に偏って接触したとき、第二列Ｌ２側の第二の玉２４が第二の内輪軌道溝２９及び第二の外輪軌道溝２７に対してすべることは、従来の複列の第一の転がり軸受の玉９２が内輪軌道溝９３及び外輪軌道溝９４に対してすべることよりも抑制される。なお、図２などでは、説明をわかりやすくするため、回転軸１１の傾きを実際よりも大きくして示している。 According to the first rolling bearing 16 of each of the above embodiments, the first inner ring 21 is rotatable with respect to one outer ring 20 independently of the second inner ring 22, and the first inner ring 21 is rotatable with respect to one outer ring 20. can rotate independently of the first inner ring 21 and relative to one outer ring 20. The first inner ring 21 and the second inner ring 22 can rotate at different rotational speeds with respect to the outer ring 20. Therefore, when the magnetic bearing device 10 enters an emergency operation state and the tilting rotating shaft 11 contacts the first inner ring 21 on the first row L2 side, the second ball 24 on the second row L2 side The fact that the balls 92 of the conventional double-row first rolling bearing slides against the inner ring raceway groove 93 and the outer ring raceway groove 94 is that the ball 92 of the conventional double-row first rolling bearing slides against the second inner ring raceway groove 29 and the second outer ring raceway groove 27. is also suppressed. In addition, in FIG. 2 and the like, in order to make the explanation easier to understand, the inclination of the rotating shaft 11 is shown larger than in reality.
　前記各形態では（図１参照）第一の転がり軸受１６は、回転軸１１の重心位置Ｇよりも上に位置する。このため、磁気軸受装置１０が非常運転状態になると、回転軸１１は、第一の転がり軸受１６よりも下となる重心位置Ｇ側の位置を基準として、傾く。すると、その回転軸１１は、第一の転がり軸受１６のうち、第一の内輪２１に先に接触する場合がある。このように、傾く回転軸１１が第一の内輪２１に偏って接触したとき、第一の内輪２１は第二の内輪２２に対して独立して回転可能であるため、第二の玉２４が第二の内輪軌道溝２９及び第二の外輪軌道溝２７に対してすべることは、従来の複列の第一の転がり軸受の玉９２が内輪軌道溝９３及び外輪軌道溝９４に対してすべることよりも抑制される。その結果、第一の転がり軸受１６は、第二の玉２４、第二の内輪軌道溝２９、及び第二の外輪軌道溝２７の少なくともいずれかが焼付くことを、を防止できる。 In each of the above embodiments (see FIG. 1), the first rolling bearing 16 is located above the center of gravity G of the rotating shaft 11. Therefore, when the magnetic bearing device 10 enters the emergency operating state, the rotating shaft 11 tilts with respect to a position on the center of gravity G side below the first rolling bearing 16. Then, the rotating shaft 11 may come into contact with the first inner ring 21 of the first rolling bearing 16 first. In this way, when the tilting rotating shaft 11 contacts the first inner ring 21 unevenly, the first inner ring 21 is rotatable independently of the second inner ring 22, so the second ball 24 Sliding with respect to the second inner ring raceway groove 29 and second outer ring raceway groove 27 means that the balls 92 of the conventional double-row first rolling bearing slide with respect to the inner ring raceway groove 93 and the outer ring raceway groove 94. more suppressed. As a result, the first rolling bearing 16 can prevent at least one of the second balls 24, the second inner raceway groove 29, and the second outer raceway groove 27 from seizing.
　そして、回転軸１１が第一の内輪２１に接触した後に、その回転軸１１はさらに第二の内輪２２に接触することができる。回転軸１１は、第一列Ｌ１の軸受部と第二列Ｌ２の軸受部とで支持される。 After the rotating shaft 11 contacts the first inner ring 21, the rotating shaft 11 can further contact the second inner ring 22. The rotating shaft 11 is supported by bearings in the first row L1 and bearings in the second row L2.
　前記各形態の第一の転がり軸受１６によれば、下記の作用効果を奏することも可能である。
　前記各形態の第一の転がり軸受１６を使用することで、傾いた状態にある回転軸１１から第一の転がり軸受１６が受ける径方向の荷重は、上側の第一列Ｌ１の軸受部が受ける荷重と、下側の第二列Ｌ２の軸受部が受ける荷重とに分散する。
　前記各形態の第一の転がり軸受１６は、回転軸１１から第一列Ｌ１の軸受部が受ける径方向の荷重と、回転軸１１から第二列Ｌ２の軸受部が受ける径方向の荷重との差を、従来技術の複列の第一の転がり軸受９０のその差に対して小さくすることが可能となる。
　前記各形態の第一の転がり軸受１６は、の負荷容量を従来技術の単列の第一の転がり軸受の負荷容量に対して大きくすることが可能となる。 According to the first rolling bearing 16 of each of the above embodiments, it is also possible to achieve the following effects.
By using the first rolling bearings 16 of each of the above embodiments, the radial load received by the first rolling bearings 16 from the rotating shaft 11 in an inclined state is received by the bearings in the upper first row L1. The load is distributed between the load and the load received by the bearing section of the lower second row L2.
The first rolling bearings 16 of each of the above-mentioned configurations have a radial load that is applied from the rotating shaft 11 to the bearings in the first row L1, and a radial load that is received from the rotating shaft 11 to the bearings in the second row L2. The difference can be made smaller than that of the double-row first rolling bearing 90 of the prior art.
The first rolling bearing 16 of each of the above embodiments can have a load capacity larger than that of the conventional single-row first rolling bearing.
　前記各形態での第一の転がり軸受１６は、第一の内輪２１と第二の内輪２２との間に、軸方向について隙間Ｅを有する。このため、第一の内輪２１及び第二の内輪２２のうちの一方又は双方が変位しても、第一の内輪２１及び第二の内輪２２それぞれは、相互に接触不能であり、独立して回転可能である。 The first rolling bearing 16 in each of the above embodiments has a gap E between the first inner ring 21 and the second inner ring 22 in the axial direction. Therefore, even if one or both of the first inner ring 21 and the second inner ring 22 are displaced, the first inner ring 21 and the second inner ring 22 cannot contact each other and are independent of each other. It is rotatable.
〔第一の転がり軸受１６の変形例〕
　図２に示す第一の転がり軸受１６のさらに別の変形例として、以下の構成が挙げられる。
　複数の第一の玉２３を含む玉セットのピッチ径Ｄ１は、複数の第二の玉２４を含む玉セットのピッチ径Ｄ２よりも、小さい（変形例１）。
　第一の玉２３の直径ｄ１は、第二の玉２４の直径ｄ２よりも、小さい（変形例２）。
　第一列Ｌ１の軸受部に含まれる第一の玉２３の数は、第二列Ｌ２の軸受部に含まれる第二の玉２４数よりも、少ない（変形例３）。
　第一列Ｌ１の軸受部に含まれる第一の玉２３の数は、第二列Ｌ２の軸受部に含まれる第二の玉２４の数よりも、多い（変形例４）。 [Modified example of first rolling bearing 16]
Still another modification of the first rolling bearing 16 shown in FIG. 2 includes the following configuration.
The pitch diameter D1 of the ball set including the plurality of first balls 23 is smaller than the pitch diameter D2 of the ball set including the plurality of second balls 24 (Modification 1).
The diameter d1 of the first ball 23 is smaller than the diameter d2 of the second ball 24 (Modification 2).
The number of first balls 23 included in the bearings in the first row L1 is smaller than the number of second balls 24 included in the bearings in the second row L2 (Modification 3).
The number of first balls 23 included in the bearings in the first row L1 is greater than the number of second balls 24 included in the bearings in the second row L2 (Modification 4).
　図２に示す形態は、前記の変形例１、変形例２、変形例３及び変形例４の一方、の構成の一つ又は複数を組み合わせてもよい。
　図３に示す形態は、前記の変形例２、変形例３及び変形例４の一方、の構成の一つ又は複数を組み合わせてもよい。
　図４に示す形態は、前記の変形例１、変形例３及び変形例４の一方、の構成の一つ又は複数を組み合わせてもよい。
　なお、軸受部の負荷容量は、ピッチ径が大きいほど、また、玉の直径が大きいほど、また、玉の数が多いほど、大きくなる。 The form shown in FIG. 2 may be a combination of one or more of the configurations of Modification 1, Modification 2, Modification 3, and Modification 4 described above.
The form shown in FIG. 3 may be a combination of one or more of the configurations of Modification 2, Modification 3, and Modification 4 described above.
The form shown in FIG. 4 may be a combination of one or more of the configurations of Modification 1, Modification 3, and Modification 4 described above.
Note that the load capacity of the bearing section increases as the pitch diameter increases, as the diameter of the balls increases, and as the number of balls increases.
〔第一の転がり軸受１６の入れ溝について〕
　前記各形態の第一の転がり軸受１６は総玉軸受である。前記各形態の第一の転がり軸受１６は、組み立てを可能とするために、各軌道輪に玉２３，２４のための入れ溝を有する。その入れ溝について以下説明する。なお、以下の各例において、第一の内輪２１は第二の内輪２２よりも上に設けられている。 [About the groove of the first rolling bearing 16]
The first rolling bearing 16 of each of the above embodiments is a full ball bearing. The first rolling bearing 16 of each type has grooves for the balls 23 and 24 in each bearing ring to enable assembly. The groove will be explained below. Note that in each of the following examples, the first inner ring 21 is provided above the second inner ring 22.
（第一の例）
　図２の第一の転がり軸受１６の入れ溝は、第一の例である。
　第一の玉２３のための入れ溝５２は、外輪２０の内周に、上側の外輪側面５１と第一の外輪軌道溝２６とをつないで設けられている。第一の玉２３のための入れ溝５２は、外輪２０の上側の肩３６ａの周方向の一部を除去した形状である。
　第一の玉２３のための入れ溝５４は、第一の内輪２１の外周に、上側の内輪側面５３と第一の内輪軌道溝２８とをつないで設けられている。第一の玉２３のための入れ溝５４は、第１の内輪２１の上側の肩３７の周方向の一部を除去した形状である。
　第二の玉２４のための入れ溝５７は、外輪２０の内周に、下側の外輪側面５６と第二の外輪軌道溝２７とをつないで設けられている。第二の玉２４のための入れ溝５７は、外輪２０の下側の肩３６ｂの周方向の一部を除去した形状である。
　第二の玉２４のための入れ溝５９は、第二の内輪２２の外周に、下側の内輪側面５８と第二の内輪軌道溝２９とをつないで設けられている。第二の玉２４のための入れ溝５９は、第２の内輪２２の下側の肩３８の周方向の一部を除去した形状である。
　第一の例の入れ溝を有する第一の転がり軸受１６は、第一列Ｌ１の軸受部と第二列Ｌ２の軸受部とが独立して組み立てられる。 (first example)
The insertion groove of the first rolling bearing 16 in FIG. 2 is a first example.
The insertion groove 52 for the first ball 23 is provided on the inner periphery of the outer ring 20 so as to connect the upper outer ring side surface 51 and the first outer ring raceway groove 26 . The groove 52 for the first ball 23 has a shape obtained by removing a portion of the upper shoulder 36a of the outer ring 20 in the circumferential direction.
A groove 54 for the first ball 23 is provided on the outer periphery of the first inner ring 21 so as to connect the upper inner ring side surface 53 and the first inner ring raceway groove 28 . The groove 54 for the first ball 23 has a shape obtained by removing a portion of the upper shoulder 37 of the first inner ring 21 in the circumferential direction.
A groove 57 for the second ball 24 is provided on the inner periphery of the outer ring 20 so as to connect the lower outer ring side surface 56 and the second outer ring raceway groove 27 . The groove 57 for the second ball 24 has a shape obtained by removing a portion of the lower shoulder 36b of the outer ring 20 in the circumferential direction.
A groove 59 for the second ball 24 is provided on the outer periphery of the second inner ring 22 so as to connect the lower inner ring side surface 58 and the second inner ring raceway groove 29 . The groove 59 for the second ball 24 has a shape obtained by removing a portion of the lower shoulder 38 of the second inner ring 22 in the circumferential direction.
In the first rolling bearing 16 having the groove in the first example, the bearing portions of the first row L1 and the bearing portions of the second row L2 are assembled independently.
　図３に示す第一の転がり軸受１６、及び、図４に示す第一の転がり軸受１６に関して、入れ溝は、図２に示す第一の転がり軸受１６と同じである。 Regarding the first rolling bearing 16 shown in FIG. 3 and the first rolling bearing 16 shown in FIG. 4, the grooves are the same as the first rolling bearing 16 shown in FIG. 2.
（第二の例）
　図５は、図２に示す第一の転がり軸受１６のさらに別の変形例を示す断面図である。
　図５に示す第二の例は、図２に示す第一の例と比較して、第二列Ｌ２の軸受部のための入れ溝の構成が異なる。
　図５に示す第一の転がり軸受１６の入れ溝を除く構成は、図２に示す第一の転がり軸受１６の入れ溝を除く構成と同じであり、その説明について、省略する。図２に示す第一の転がり軸受１６の入れ溝を除く構成と同じ構成である図５に示す第一の転がり軸受１６の入れ溝を除く構成の符号は、図２に示す第一の転がり軸受１６の構成の符号と同じである。
　第二の例において、図５に示す第一の転がり軸受１６は、第一の例における図２に示す第一の転がり軸受１６の、第二の玉２４のための入れ溝５７、５９を有さない。
　一方、図５に示す第二の例において、第一の転がり軸受１６は、外輪２０の内周の軸方向の中央に、第二の玉２４のための入れ溝７１が設けられている。第二の玉２４のための入れ溝７１は、中間の肩３０の周方向の一部を除去した形状であり、第一の外輪軌道溝２６と第二の外輪軌道溝２７とをつなぐ。
　第二の玉２４のための入れ溝７４は、第二の内輪２２の外周に、上側の内輪側面７３と第二の内輪軌道溝２９とをつないで設けられている。第二の玉２４のための入れ溝７４は、第２の内輪２２の上側の肩３８の周方向の一部を除去した形状である。
　第一の玉２３のための入れ溝５２は、外輪２０の内周に、上側の外輪側面５１と第一の外輪軌道溝２６とをつないで設けられている。第一の玉２３のための入れ溝５２は、外輪２０の上側の肩３６ａの周方向の一部を除去した形状である。
　第一の玉２３のための入れ溝５４は、第一の内輪２１の外周に、上側の内輪側面５３と第一の内輪軌道溝２８とをつないで設けられている。第一の玉２３のための入れ溝５４は、第１の内輪２１の上側の肩３７の周方向の一部を除去した形状である。
　第二の例の第一の転がり軸受１６は、第二列Ｌ２の軸受部が組み立てられてから、第一列Ｌ１の軸受部が組み立てられる。 (Second example)
FIG. 5 is a sectional view showing still another modification of the first rolling bearing 16 shown in FIG. 2. In FIG.
The second example shown in FIG. 5 differs from the first example shown in FIG. 2 in the configuration of the grooves for the bearings in the second row L2.
The structure of the first rolling bearing 16 shown in FIG. 5 except for the insertion groove is the same as the structure of the first rolling bearing 16 shown in FIG. 2 except for the insertion groove, and the description thereof will be omitted. The reference numerals of the first rolling bearing 16 shown in FIG. 5 have the same configuration as the first rolling bearing 16 shown in FIG. 2 except for the insertion grooves. The code is the same as that of No.16.
In the second example, the first rolling bearing 16 shown in FIG. 5 has grooves 57, 59 for the second balls 24 of the first rolling bearing 16 shown in FIG. 2 in the first example. I don't.
On the other hand, in the second example shown in FIG. 5, the first rolling bearing 16 is provided with a groove 71 for the second ball 24 at the center of the inner circumference of the outer ring 20 in the axial direction. The insertion groove 71 for the second ball 24 has a shape obtained by removing a part of the intermediate shoulder 30 in the circumferential direction, and connects the first outer ring raceway groove 26 and the second outer ring raceway groove 27.
A groove 74 for the second ball 24 is provided on the outer periphery of the second inner ring 22 to connect the upper inner ring side surface 73 and the second inner ring raceway groove 29 . The groove 74 for the second ball 24 has a shape obtained by removing a portion of the upper shoulder 38 of the second inner ring 22 in the circumferential direction.
The insertion groove 52 for the first ball 23 is provided on the inner periphery of the outer ring 20 so as to connect the upper outer ring side surface 51 and the first outer ring raceway groove 26 . The groove 52 for the first ball 23 has a shape obtained by removing a portion of the upper shoulder 36a of the outer ring 20 in the circumferential direction.
The insertion groove 54 for the first ball 23 is provided on the outer periphery of the first inner ring 21 so as to connect the upper inner ring side surface 53 and the first inner ring raceway groove 28 . The groove 54 for the first ball 23 has a shape obtained by removing a portion of the upper shoulder 37 of the first inner ring 21 in the circumferential direction.
In the first rolling bearing 16 of the second example, after the bearing parts of the second row L2 are assembled, the bearing parts of the first row L1 are assembled.
（第三の例）
　図６は、図３に示す第一の転がり軸受１６の変形例を示す断面図である。
　図６に示す第三の例は、図３に示す第一の転がり軸受１６と比較して、第二列Ｌ２の軸受部のための入れ溝の構成が異なる。
　図６に示す第一の転がり軸受１６の入れ溝を除く構成は、図３に示す第一の転がり軸受１６の入れ溝を除く構成と同じであり、その説明について、省略する。図３に示す第一の転がり軸受１６の入れ溝を除く構成と同じ構成である図６に示す第一の転がり軸受１６の入れ溝を除く構成の符号は、図３に示す第一の転がり軸受１６の構成の符号と同じである。
　第三の例である図６に示す第一の転がり軸受１６の入れ溝は、第二の例である図５に示す第一の転がり軸受１６と同じであり、その説明について、省略する。図５に示す第一の転がり軸受１６の入れ溝と同じ構成である図６に示す第一の転がり軸受１６の入れ溝の符号は、図５に示す第一の転がり軸受１６の入れ溝の符号と同じである。
　第三の例の第一の転がり軸受１６は、第二列Ｌ２の軸受部が組み立てられてから、第一列Ｌ１の軸受部が組み立てられる。 (Third example)
FIG. 6 is a sectional view showing a modification of the first rolling bearing 16 shown in FIG. 3. In FIG.
The third example shown in FIG. 6 differs from the first rolling bearing 16 shown in FIG. 3 in the configuration of the groove for the bearing portion of the second row L2.
The configuration of the first rolling bearing 16 shown in FIG. 6 except for the insertion groove is the same as the configuration of the first rolling bearing 16 shown in FIG. 3 except for the insertion groove, and the description thereof will be omitted. The reference numerals of the first rolling bearing 16 shown in FIG. 6 which have the same configuration as the first rolling bearing 16 shown in FIG. The code is the same as that of No.16.
The insertion groove of the first rolling bearing 16 shown in FIG. 6, which is a third example, is the same as that of the first rolling bearing 16 shown in FIG. 5, which is a second example, and the description thereof will be omitted. The reference numerals of the insert grooves of the first rolling bearing 16 shown in FIG. 6, which have the same configuration as the insert grooves of the first rolling bearing 16 shown in FIG. is the same as
In the first rolling bearing 16 of the third example, after the bearing parts of the second row L2 are assembled, the bearing parts of the first row L1 are assembled.
（第四の例）
　図７は、図３に示す第一の転がり軸受１６のさらに別の変形例を示す断面図である。
　図７に示す第四の例は、図３に示す第一の転がり軸受１６と比較して、入れ溝の構成が異なる。
　図７に示す第一の転がり軸受１６の入れ溝を除く構成は、図３に示す第一の転がり軸受１６の入れ溝を除く構成と同じであり、その説明について、省略する。図３に示す第一の転がり軸受１６の入れ溝を除く構成と同じ構成である図７に示す第一の転がり軸受１６の入れ溝を除く構成の符号は、図３に示す第一の転がり軸受１６の構成の符号と同じである。
　第四の例において、図７に示す第一の転がり軸受１６は、第一の例における図３に示す第一の転がり軸受１６の、第二の玉２３のための入れ溝５２、５４を有さない。
　一方、図７に示す第四の例において、図７に示す第一の転がり軸受１６は、外輪２０の内周の軸方向の中央に、第一の玉２３のための入れ溝７１が設けられている。第一の玉２３のための入れ溝７１は、中間の肩３０の周方向の一部を除去した形状であり、第一の外輪軌道溝２６と第二の外輪軌道溝２７とをつなぐ。
　第一の玉２３のための入れ溝７６は、第一の内輪２１の外周に、下側の内輪側面７５と第一の内輪軌道溝２８とをつないで設けられている。第一の玉２３のための入れ溝７６は、第１の内輪２１の下側の肩３７の周方向の一部を除去した形状である。
　第二の玉２４のための入れ溝５７は、外輪２０の内周に、下側の外輪側面５６と第二の外輪軌道溝２７とをつないで設けられている。第二の玉２４のための入れ溝５７は、外輪２０の下側の肩３６ｂの周方向の一部を除去した形状である。
　第二の玉２４のための入れ溝５９は、第二の内輪２２の外周に、下側の内輪側面５８と第二の内輪軌道溝２９とをつないで設けられている。第二の玉２４のための入れ溝５９は、第２の内輪２２の下側の肩３８の周方向の一部を除去した形状である。
　第四の例の第一の転がり軸受１６は、第一列Ｌ１の軸受部が組み立てられてから、第二列Ｌ２の軸受部が組み立てられる。 (Fourth example)
FIG. 7 is a sectional view showing still another modification of the first rolling bearing 16 shown in FIG.
The fourth example shown in FIG. 7 is different from the first rolling bearing 16 shown in FIG. 3 in the configuration of the insertion groove.
The configuration of the first rolling bearing 16 shown in FIG. 7 except for the insertion groove is the same as the configuration of the first rolling bearing 16 shown in FIG. 3 except for the insertion groove, and the description thereof will be omitted. The reference numerals of the first rolling bearing 16 shown in FIG. 7 which have the same configuration as the first rolling bearing 16 shown in FIG. The code is the same as that of No.16.
In the fourth example, the first rolling bearing 16 shown in FIG. 7 has grooves 52, 54 for the second balls 23 of the first rolling bearing 16 shown in FIG. 3 in the first example. I don't.
On the other hand, in the fourth example shown in FIG. 7, the first rolling bearing 16 shown in FIG. ing. The insertion groove 71 for the first ball 23 has a shape obtained by removing a part of the intermediate shoulder 30 in the circumferential direction, and connects the first outer ring raceway groove 26 and the second outer ring raceway groove 27.
The insertion groove 76 for the first ball 23 is provided on the outer periphery of the first inner ring 21 so as to connect the lower inner ring side surface 75 and the first inner ring raceway groove 28 . The groove 76 for the first ball 23 has a shape obtained by removing a portion of the lower shoulder 37 of the first inner ring 21 in the circumferential direction.
A groove 57 for the second ball 24 is provided on the inner periphery of the outer ring 20 so as to connect the lower outer ring side surface 56 and the second outer ring raceway groove 27 . The groove 57 for the second ball 24 has a shape obtained by removing a portion of the lower shoulder 36b of the outer ring 20 in the circumferential direction.
A groove 59 for the second ball 24 is provided on the outer periphery of the second inner ring 22 so as to connect the lower inner ring side surface 58 and the second inner ring raceway groove 29 . The groove 59 for the second ball 24 has a shape obtained by removing a portion of the lower shoulder 38 of the second inner ring 22 in the circumferential direction.
In the first rolling bearing 16 of the fourth example, the bearing portions of the first row L1 are assembled, and then the bearing portions of the second row L2 are assembled.
（第五の例）
　図８は、図４に示す第一の転がり軸受１６の変形例を示す断面図である。
　図８に示す第五の例は、図４に示す第一の転がり軸受１６と比較して、入れ溝の構成が異なる。
　図８に示す第一の転がり軸受１６の入れ溝を除く構成は、図４に示す第一の転がり軸受１６の入れ溝を除く構成と同じであり、その説明について、省略する。図４に示す第一の転がり軸受１６の入れ溝を除く構成と同じ構成である図８に示す第一の転がり軸受１６の入れ溝を除く構成の符号は、図４に示す第一の転がり軸受１６の構成の符号と同じである。
　第五の例である図８に示す第一の転がり軸受１６の入れ溝は、第二の例である図５に示す第一の転がり軸受１６と同じであり、その説明について、省略する。図５に示す第一の転がり軸受１６の入れ溝と同じ構成である図８に示す第一の転がり軸受１６の入れ溝の符号は、図５に示す第一の転がり軸受１６の入れ溝の符号と同じである。
　第五の例の第一の転がり軸受１６は、第二列Ｌ２の軸受部が組み立てられてから、第一列Ｌ１の軸受部が組み立てられる。 (Fifth example)
FIG. 8 is a sectional view showing a modification of the first rolling bearing 16 shown in FIG. 4. FIG.
The fifth example shown in FIG. 8 is different from the first rolling bearing 16 shown in FIG. 4 in the configuration of the insertion groove.
The configuration of the first rolling bearing 16 shown in FIG. 8 except for the insertion groove is the same as the configuration of the first rolling bearing 16 shown in FIG. 4 except for the insertion groove, and the description thereof will be omitted. The reference numerals of the first rolling bearing 16 shown in FIG. 8 have the same configuration as the first rolling bearing 16 shown in FIG. 4 except for the insertion groove. The code is the same as that of No.16.
The insertion groove of the first rolling bearing 16 shown in FIG. 8, which is a fifth example, is the same as that of the first rolling bearing 16 shown in FIG. 5, which is a second example, and the description thereof will be omitted. The reference numerals of the insert grooves of the first rolling bearing 16 shown in FIG. 8, which have the same configuration as the insert grooves of the first rolling bearing 16 shown in FIG. is the same as
In the first rolling bearing 16 of the fifth example, the bearing parts of the second row L2 are assembled, and then the bearing parts of the first row L1 are assembled.
（第六の例）
　図９は、図４に示す第一の転がり軸受１６のさらに別の変形例を示す断面図である。
　図９に示す第六の例は、図４に示す第一の転がり軸受１６と比較して、入れ溝の構成が異なる。
　図９に示す第一の転がり軸受１６の入れ溝を除く構成は、図４に示す第一の転がり軸受１６の入れ溝を除く構成と同じであり、その説明について、省略する。図４に示す第一の転がり軸受１６の入れ溝を除く構成と同じ構成である図９に示す第一の転がり軸受１６の入れ溝を除く構成の符号は、図４に示す第一の転がり軸受１６の構成の符号と同じである。
　第六の例である図９に示す第一の転がり軸受１６の入れ溝は、第四の例である図７に示す第一の転がり軸受１６と同じであり、その説明について、省略する。図７に示す第一の転がり軸受１６の入れ溝と同じ構成である図９に示す第一の転がり軸受１６の入れ溝の符号は、図７に示す第一の転がり軸受１６の入れ溝の符号と同じである。
　第六の例の第一の転がり軸受１６は、第一列Ｌ１の軸受部が組み立てられてから、第二列Ｌ２の軸受部が組み立てられる。 (Sixth example)
FIG. 9 is a sectional view showing still another modification of the first rolling bearing 16 shown in FIG.
The sixth example shown in FIG. 9 is different from the first rolling bearing 16 shown in FIG. 4 in the configuration of the insertion groove.
The configuration of the first rolling bearing 16 shown in FIG. 9 except for the insertion groove is the same as the configuration of the first rolling bearing 16 shown in FIG. 4 except for the insertion groove, and the description thereof will be omitted. The reference numerals of the first rolling bearing 16 shown in FIG. 9, which have the same configuration as the first rolling bearing 16 shown in FIG. The code is the same as that of No.16.
The insertion groove of the first rolling bearing 16 shown in FIG. 9, which is the sixth example, is the same as that of the first rolling bearing 16 shown in FIG. 7, which is the fourth example, and the explanation thereof will be omitted. The reference numerals of the insert grooves of the first rolling bearing 16 shown in FIG. 9, which have the same configuration as the insert grooves of the first rolling bearing 16 shown in FIG. is the same as
In the first rolling bearing 16 of the sixth example, the bearing portions of the first row L1 are assembled, and then the bearing portions of the second row L2 are assembled.
〔その他について〕
　前記各形態では、軸方向、つまり、中心軸Ｃの方向が鉛直上下方向と一致する場合について説明したが、軸方向は、鉛直上下方向でなくてもよい。
　前記各形態の第一の転がり軸受１６は、第一の内輪２１を第二の内輪２２よりも上に設けていたが、第一の転がり軸受は、第一の内輪２１を第二の内輪２２よりも下に設けてもよい。 [About others]
In each of the above embodiments, a case has been described in which the axial direction, that is, the direction of the central axis C coincides with the vertical up-down direction, but the axial direction does not have to be the vertical up-down direction.
In the first rolling bearing 16 of each of the above embodiments, the first inner ring 21 was provided above the second inner ring 22; It may be provided below.
　前記実施形態は、すべての点で例示であって制限的なものではない。本発明の権利範囲は、前記実施形態ではなく請求の範囲によって示され、請求の範囲に記載された構成と均等の範囲内でのすべての変更を含む。 The above embodiments are illustrative in all respects and are not restrictive. The scope of rights of the present invention is indicated by the scope of the claims, not the embodiments, and includes all modifications within the scope of equivalents to the configurations described in the scope of the claims.
　１０　磁気軸受装置
　１１　回転軸
　１２　ハウジング
　１３ａ，１３ｂ　ラジアル磁気軸受
　１４ａ，１４ｂ　アキシアル磁気軸受
　１６　第一の転がり軸受（複列深溝玉軸受）
　１７　第二の転がり軸受
　２０　外輪
　２０ａ　第一部分
　２０ｂ　第二部分
　２１　第一の内輪
　２２　第二の内輪
　２３　第一の玉
　２４　第二の玉
　２６　第一の外輪軌道溝
　２７　第二の外輪軌道溝
　２８　第一の内輪軌道溝
　２９　第二の内輪軌道溝
　５１　外輪側面
　５２　入れ溝
　５３　内輪側面
　５４　入れ溝
　Ｅ　隙間
　Ｇ　重心位置 10 Magnetic bearing device 11 Rotating shaft 12 Housing 13a, 13b Radial magnetic bearing 14a, 14b Axial magnetic bearing 16 First rolling bearing (double row deep groove ball bearing)
17 Second rolling bearing 20 Outer ring 20a First part 20b Second part 21 First inner ring 22 Second inner ring 23 First ball 24 Second ball 26 First outer ring raceway groove 27 Second outer ring raceway groove 28 First inner ring raceway groove 29 Second inner ring raceway groove 51 Outer ring side surface 52 Insertion groove 53 Inner ring side surface 54 Insertion groove E Gap G Center of gravity position

Claims (4)

  1. 　内周に第一の外輪軌道溝及び第二の外輪軌道溝が設けられている外輪と、
    　外周に第一の内輪軌道溝が設けられている第一の内輪と、
    　外周に第二の内輪軌道溝が設けられている第二の内輪と、
    　前記第一の内輪軌道溝と前記第一の外輪軌道溝との間に設けられている複数の第一の玉と、
    　前記第二の内輪軌道溝と前記第二の外輪軌道溝との間に設けられている複数の第二の玉と、
    　を備え、
    　前記外輪は、前記第一の外輪軌道溝が設けられている第一部分と、前記第一部分と一体であり前記第二の外輪軌道溝が設けられている第二部分と、を有し、
    　前記第一の内輪と前記第二の内輪とは別体である、
    　複列深溝玉軸受。     an outer ring having a first outer ring raceway groove and a second outer ring raceway groove on the inner periphery;
    a first inner ring having a first inner ring raceway groove on its outer periphery;
    a second inner ring having a second inner ring raceway groove on its outer periphery;
    a plurality of first balls provided between the first inner raceway groove and the first outer raceway groove;
    a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove;
    Equipped with
    The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove,
    The first inner ring and the second inner ring are separate bodies,
    Double row deep groove ball bearing.
  2. 　前記第一の内輪と前記第二の内輪との間に、軸方向について隙間が設けられている、請求項１に記載の複列深溝玉軸受。 The double-row deep groove ball bearing according to claim 1, wherein a gap is provided in the axial direction between the first inner ring and the second inner ring.
  3. 　ハウジングと、
    　前記ハウジング内に設けられている回転軸と、
    　前記回転軸を支持可能である第一の転がり軸受と、
    　前記回転軸を支持可能である第二の転がり軸受と、
    　前記回転軸を径方向に支持可能であるラジアル磁気軸受と、
    　前記回転軸を軸方向に支持可能であるアキシアル磁気軸受と、
    　を備え、
    　前記第一の転がり軸受は、前記回転軸の重心位置よりも、前記回転軸の軸方向の第一の側に設けられていて、前記第二の転がり軸受は、前記第一の転がり軸受よりも、前記回転軸の軸方向の第二の側に設けられていて、
    　前記第一の転がり軸受は、
    　　内周に第一の外輪軌道溝及び第二の外輪軌道溝が設けられ前記ハウジングに固定される第一外輪と、
    　　外周に第一の内輪軌道溝が設けられている第一の内輪と、
    　　外周に第二の内輪軌道溝が設けられている第二の内輪と、
    　　前記第一の内輪軌道溝と前記第一の外輪軌道溝との間に設けられている複数の第一の玉と、
    　　前記第二の内輪軌道溝と前記第二の外輪軌道溝との間に設けられている複数の第二の玉と、
    　を備え、
    　前記外輪は、前記第一の外輪軌道溝が設けられている第一部分と、前記第一部分と一体であり前記第二の外輪軌道溝が設けられている第二部分と、を有し、
    　前記第一の内輪と前記第二の内輪とは別体であり、
    　、前記回転軸が前記ラジアル磁気軸受及び前記アキシアル磁気軸受によって支持されて回転している状態で、前記第一の内輪及び前記第二の内輪は、前記回転軸と非接触であり、前記ラジアル磁気軸受が前記回転軸を支持不能になると、前記第一の転がり軸受は、前記回転軸を径方向に支持する、
    　磁気軸受装置。     housing and
    a rotating shaft provided within the housing;
    a first rolling bearing capable of supporting the rotating shaft;
    a second rolling bearing capable of supporting the rotating shaft;
    a radial magnetic bearing capable of supporting the rotating shaft in a radial direction;
    an axial magnetic bearing capable of supporting the rotating shaft in the axial direction;
    Equipped with
    The first rolling bearing is provided on a first side in the axial direction of the rotating shaft with respect to the center of gravity of the rotating shaft, and the second rolling bearing is provided on a first side of the rotating shaft with respect to the center of gravity of the rotating shaft. , provided on a second axial side of the rotating shaft,
    The first rolling bearing is
    a first outer ring that is fixed to the housing and has a first outer ring raceway groove and a second outer ring raceway groove on its inner periphery;
    a first inner ring having a first inner ring raceway groove on its outer periphery;
    a second inner ring having a second inner ring raceway groove on its outer periphery;
    a plurality of first balls provided between the first inner raceway groove and the first outer raceway groove;
    a plurality of second balls provided between the second inner raceway groove and the second outer raceway groove;
    Equipped with
    The outer ring has a first portion in which the first outer ring raceway groove is provided, and a second portion that is integral with the first portion and is provided with the second outer ring raceway groove,
    The first inner ring and the second inner ring are separate bodies,
    , while the rotating shaft is rotating while being supported by the radial magnetic bearing and the axial magnetic bearing, the first inner ring and the second inner ring are out of contact with the rotating shaft, and the radial magnetic bearing When the bearing becomes unable to support the rotating shaft, the first rolling bearing supports the rotating shaft in the radial direction.
    Magnetic bearing device.
  4. 　前記第一の転がり軸受は総玉軸受であり、
    　前記第一の内輪は前記第二の内輪よりも軸方向の第一の側に設けられていて、
    　前記外輪の内周に、前記第一の側の外輪側面と前記第一の外輪軌道溝とをつなぐ前記第一の玉のための入れ溝が設けられていて、
    　前記第一の内輪の外周に、前記第一の側の内輪側面と前記第一の内輪軌道溝とをつなぐ前記第一の玉のための入れ溝が設けられている、
    　請求項３に記載の磁気軸受装置。     The first rolling bearing is a full ball bearing,
    The first inner ring is provided on a first side in the axial direction than the second inner ring,
    An insertion groove for the first ball connecting the first outer ring side surface and the first outer ring raceway groove is provided on the inner periphery of the outer ring,
    An insertion groove for the first ball connecting the inner ring side surface on the first side and the first inner ring raceway groove is provided on the outer periphery of the first inner ring.
    The magnetic bearing device according to claim 3.
PCT/JP2022/024441 2022-06-20 2022-06-20 Double-row deep-groove ball bearing and magnetic bearing device WO2023248266A1 (en)

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PCT/JP2022/024441 WO2023248266A1 (en) 2022-06-20 2022-06-20 Double-row deep-groove ball bearing and magnetic bearing device
TW111145598A TW202400912A (en) 2022-06-20 2022-11-29 Double-row deep-groove ball bearing and magnetic bearing device

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6140510U (en) * 1984-08-16 1986-03-14 セイコー精機株式会社 magnetic bearing device
JPH07133828A (en) * 1993-11-10 1995-05-23 Seiko Seiki Co Ltd Solid lubricating bearing
JPH07167139A (en) * 1993-12-17 1995-07-04 Nippon Seiko Kk Double row ball bearing and manufacture thereof with preload
JP2002168244A (en) * 2000-11-30 2002-06-14 Koyo Seiko Co Ltd Rolling bearing
JP2004116558A (en) * 2002-09-24 2004-04-15 Nsk Ltd Rolling bearing for protection of non-contact type bearing

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6140510U (en) * 1984-08-16 1986-03-14 セイコー精機株式会社 magnetic bearing device
JPH07133828A (en) * 1993-11-10 1995-05-23 Seiko Seiki Co Ltd Solid lubricating bearing
JPH07167139A (en) * 1993-12-17 1995-07-04 Nippon Seiko Kk Double row ball bearing and manufacture thereof with preload
JP2002168244A (en) * 2000-11-30 2002-06-14 Koyo Seiko Co Ltd Rolling bearing
JP2004116558A (en) * 2002-09-24 2004-04-15 Nsk Ltd Rolling bearing for protection of non-contact type bearing

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