JP2003083340A - Antifriction bearing with built-in motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive antifriction bearing with built-in motor capable of being assembled by simple works while achieving high machine accuracy and high level compactness. SOLUTION: An antifriction bearing with built-in motor consisting of a bearing part 10 with an inner ring, an outer ring and a plurality of rolling elements and a motor part 12 with a stator 34 and a rotor 26 for rotationally driving the inner ring and outer ring of the bearing part 10 in a relative manner has a bearing part 10 with the first ball race 18 formed by coaxially connecting an end surface of the inner ring to a cylinder-shaped inner fixing part 18a and the second ball race 24 formed by coaxially connecting an end surface of the outer ring to a cylinder-shaped outer fixing part 24a and a stator 20 and rotor 26 of the motor 12 are arranged between the inner fixing part 18a of the first ball race 18 and the outer fixing part 24a of the second ball race 24 in radial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing with a built-in motor used for driving devices such as robots, industrial automation equipment, computer equipment and peripheral equipment.

[0002]

2. Description of the Related Art Factory automation (FA)
As a direct drive motor used in this field, there is, for example, a structure shown in FIG. 11 described in JP-A-63-213457. This direct drive motor uses a cross roller bearing 11 as a motor bearing.
No. 0 is used, and an encoder 114 is held radially inside and a stator 116 is held axially inside the bearing via a housing 112. The rotor 120 and the slit plate 122 of the encoder 114 are fixed to the outer ring of the bearing via the rotor hub 118, and the rotor hub 118 is rotated by the driving force of the motor formed by the rotor 120 and the stator 116. There is.

FIG. 12 shows an example of the structure of an exciting coil provided on the stator 116. Here, three phases (A phase, B phase, C
Phase) excitation circuit is used. A plurality of radially protruding salient poles 124a to 124l are formed on the stator 116, and a conductor is wound around each of these salient poles to form a pole. The A-phase is wound in series from the salient pole 124a every other two salient poles 124d, 124g, 124j in series, and the B-phase is salient poles 124b, 124e, 124h, 12 in series.
4k is wound in series and the C phase is salient poles 124c, 124
It is wound in series on f, 124i and 124l. The positional relationship between the teeth provided on the facing surfaces of the stator 116 and the rotor 120 is PM (Permanent-magnet Mo
tor: Permanent magnet motor) type three-phase pulse motor.

FIG. 13 is an explanatory view showing the principle of rotation of the rotor 120. The magnetic flux generated by the salient poles of the stator 116 is
It can be expressed as the sum φO = φM + φC of the bias magnetic flux φM generated by the permanent magnet and the exciting magnetic flux φC generated by passing an exciting current through the exciting coil wound around the salient poles. here,
Exciting magnetic flux φC moves in the order of A-phase → B-phase → C-phase by passing a current to the exciting coil with a 120 ° phase difference in the order of A-phase → B-phase → C-phase from the salient pole. Then, the magnetic flux part of φO moves. Therefore, the rotor 120 is attracted to this magnetic flux portion, and a rotational driving force is generated in the rotor 120.

[0005] As another example of the structure, the actual construction of Sho 62-6.
There is a structure shown in FIG. 14 described in Japanese Patent No. 8455. This direct drive motor uses a cross roller bearing 110, a stator 138 is fixed to a frame 126 connected to the outer ring of the bearing, and a rotor 130 is provided on the shaft side so as to face the inner diameter side of the stator 138. Further, the structure is such that a detector 132 for position, speed, etc. is arranged inside the shaft that fixes the rotor 130.

As another example of the configuration, an example of a motor used in computer equipment is found in Japanese Patent Laid-Open No. 9-56108. In the publication, balls are provided between an outer peripheral rolling groove formed on the inner peripheral surface of an outer ring and an inner peripheral rolling groove formed on the outer peripheral surface of a large diameter portion of a two-stage shaft having a large diameter portion and a small diameter portion. There is provided a composite bearing device in which a ball is interposed between an inner peripheral rolling groove formed on the outer periphery of the inner ring fitted to the small diameter portion of the two-stage shaft and an outer peripheral rolling groove formed on the inner surface of the sleeve outer ring. It is disclosed. A rotor and a stator are arranged on the outer peripheral side of the sleeve outer ring of the composite bearing device.

[0007]

However, in any of the above-mentioned configurations, the rotor and the stator, which are the drive sources, and the detectors are arranged inside the motor separately from the bearings. Due to the space, it was difficult to downsize the device. JP-A-63-21
In the configuration of Japanese Patent No. 3457, the rotor 120 and the stator 116 are arranged adjacent to the cross roller bearing 110 in the axial direction, the detector (encoder) 114 is arranged inside the cross roller bearing 110 in the radial direction, and the actual opening 62 -6
In the configuration of Japanese Patent No. 8455, the detector 132 is connected to the rotor 13
By accommodating it in the inside in the radial direction of 0, the length in the axial direction is shortened, and although it has been made somewhat compact, it has not yet reached a sufficient level. Further, along with this downsizing, the entire structure of the bearing and the motor is complicated, the number of parts is increased, and the assembly process is also complicated, which causes a problem of increased cost. Further, it is difficult to obtain rotational accuracy with respect to the shaft during assembly, and it is difficult to assemble with sufficient accuracy. Further, in the configuration of Japanese Patent Application Laid-Open No. 9-56108, the rotor and the stator are arranged on the outer peripheral side of the composite bearing, which is also difficult to downsize.

The present invention has been made in view of the above problems of the prior art, and is a low-cost built-in motor which has a high mechanical precision, can be assembled by a simple work, and can be made compact at a high level. The purpose is to provide a rolling bearing.

[0009]

In order to achieve the above object, a rolling bearing with a built-in motor according to claim 1 of the present invention comprises:
A roller bearing with a built-in motor, comprising: a bearing part having an inner ring, an outer ring, and a plurality of rolling elements; and a motor part having a stator and a rotor for relatively rotating the inner ring and the outer ring of the bearing part. Is a first bearing ring formed by coaxially forming a cylindrical inner fixing portion on one end face of the inner ring, and a second bearing ring formed by coaxially forming a cylindrical outer fixing portion on one end face of the outer ring. And a stator ring and a rotor of the motor unit disposed between the inner fixing portion of the first bearing ring and the outer fixing portion of the second bearing ring when viewed in the radial direction. Is characterized by.

In this rolling bearing with a built-in motor, the bearing portion has a first bearing ring formed by coaxially connecting a cylindrical inner fixed portion to one end surface of the inner ring, and a cylindrical outer fixed portion to one end surface of the outer ring. And a second race that is coaxially connected to each other by way of rolling elements, and the inner fixed portion that extends from the end of the first race and the end that extends from the end of the second race By arranging the stator and rotor of the motor part in the space between the outer fixed part and the outer fixed part, the motor part is substantially housed inside the rolling bearing, and it is possible to achieve a significant downsizing and the bearing. The machine precision of can be maintained at high precision close to that of rolling bearings. Moreover, since the structure is simple, the assembling work is simplified and the cost is reduced.

In the rolling bearing with a built-in motor according to the present invention, the stator of the motor section is fixed to the outer circumference of the inner fixed section, and the rotor of the motor section is fixed to the inner circumference of the outer fixed section. The first raceway ring is fixedly driven, and the second raceway wheel is rotated side, and the respective raceway wheels are driven to rotate relative to each other.

In this rolling bearing with a built-in motor, the first bearing ring is fixed to the fixed side by the stator fixed to the outer circumference of the inner fixed portion and the rotor fixed to the inner circumference of the outer fixed portion.
Each bearing ring is driven to rotate relative to the second bearing ring on the rotation side.

In the rolling bearing with a built-in motor according to a third aspect of the present invention, the rotor of the motor section is fixed to the outer circumference of the inner fixed section, and the stator of the motor section is fixed to the inner circumference of the outer fixed section. The first orbital ring is driven to rotate, and the second orbital wheel is fixed to drive the orbital rings relative to each other.

In this rolling bearing with a built-in motor, the first bearing ring is rotated by the rotor fixed to the outer periphery of the inner fixed portion and the stator fixed to the inner periphery of the outer fixed portion.
The respective bearing rings are driven to rotate relative to each other with the second bearing ring as the fixed side.

According to another aspect of the present invention, in the rolling bearing with a built-in motor, the axial end portion of the inner fixed portion projects in the axial direction from the axial end portion of the outer fixed portion. At least a part of the stator and the motor are arranged between an axial end of the portion and an axial end of the inner fixed portion.

In this rolling bearing with a built-in motor, the stator and the rotor of the motor portion are arranged between the axial end portion of the outer fixed portion and the axial end portion of the inner fixed portion, so that assembly and maintenance are easy. is there.

According to a fifth aspect of the present invention, there is provided a rolling bearing with a built-in motor, wherein a detecting portion for detecting the rotation of the bearing portion is arranged between the inner fixing portion and the outer fixing portion.

In this rolling bearing with a built-in motor, the detecting portion is disposed between the inner fixing portion and the outer fixing portion, so that the detecting portion is substantially housed inside the rolling bearing, and the rolling bearing is further compactified. Can be achieved.

According to a sixth aspect of the present invention, there is provided a roller bearing with a built-in motor, wherein the detecting section has a slit disk attached to a rotating side and a light irradiation detecting section attached to a fixed side, and the slit disk is fixed to the inner side. Between the portion and the outer fixed portion, the light irradiation detection portion is disposed at an end portion in the axial direction on the side opposite to the bearing portion, and the light irradiation detection portion is provided on the bearing portion side in the axial direction of the slit disk. It is characterized in that it is arranged so as to face the slit disk.

In this rolling bearing with a built-in motor, the detecting section has a slit disk and a light irradiation detecting section, and the slit disk is provided between the inner fixing section and the outer fixing section on the shaft opposite to the bearing section. The slit disk is located at the end of the axial direction of the rolling bearing with the built-in motor, by arranging the light irradiation detection section facing the slit disk on the axial bearing side of the slit disk. The slit disk can function as a seal. This simplifies the structure and further reduces the cost.

According to a seventh aspect of the present invention, the rolling bearing with a built-in motor is characterized in that at least one of the inner fixed portion and the outer fixed portion is made of a non-magnetic material.

In this rolling bearing with a built-in motor, since at least one of the inner fixed portion and the outer fixed portion is made of a non-magnetic material, the occurrence of electrolytic corrosion due to the driving of the motor portion can be prevented and the life of the bearing can be extended. At the same time, stable rotation operation can be maintained for a long period of time.

According to an eighth aspect of the present invention, there is provided a roller bearing with a built-in motor, wherein the inner fixed portion is formed separately from the inner ring.

In this rolling bearing with a built-in motor, the inner fixing portion is formed separately from the inner ring, so that the structure of the inner ring can be simplified, and the bearing portion and the motor portion are individually assembled and then both are assembled. Therefore, the assembling process can be simplified as compared with the case where the bearing is integrally formed. Furthermore, by disassembling both,
Easy maintenance.

The rolling bearing with a built-in motor according to claim 9 is characterized in that the outer fixing portion is formed separately from the outer ring.

In this rolling bearing with a built-in motor, the outer ring fixing portion is formed separately from the outer ring, so that the structure of the outer ring can be simplified and the bearing portion and the motor portion are individually assembled and then both are assembled. Therefore, the assembling process can be simplified as compared with the case where the bearing is integrally formed. Furthermore, by disassembling both,
Easy maintenance.

According to a tenth aspect of the present invention, there is provided a roller bearing with a built-in motor, wherein the bearing portion is a cross roller bearing.

In this rolling bearing with a built-in motor, by using a cross roller bearing for the bearing portion, one bearing can receive a radial load, an axial load in both directions, and a moment load, and the axial length of the bearing can be shortened. Is advantageous, and the assembling work can be facilitated.

According to an eleventh aspect of the present invention, a rolling bearing with a built-in motor is characterized in that the rolling element is made of a ceramic material.

In this rolling bearing with a built-in motor, by using a ceramic material for the rolling elements, electrolytic corrosion due to the motor portion can be prevented, and the rotating performance of the bearing itself and the rigidity of the bearing can be increased.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a roller bearing with a built-in motor according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a first embodiment of a roller bearing with a built-in motor according to the present invention, in which (a) is a sectional view,
(B) is a side view showing a partial cross section. The rolling bearing 100 with a built-in motor according to the present embodiment generally includes the bearing portion 1
0, the motor unit 12, and the detection unit 14, and the motor unit 12 and the detection unit 14 are arranged inside the bearing unit 10.

The bearing portion 10 receives a radial load, an axial load in both directions, and a moment load by one bearing, and is advantageous in shortening the axial length of the bearing, and a cross roller bearing 16 which is easy to assemble. I am using.
Inner ring (first bearing ring) 18 of the cross roller bearing 16
One end of is formed in a cylindrical shape extending in the axial direction, and the light irradiation detection serving as a fixing portion of the stator 20 of the motor unit 12 and the rotary encoder of the detecting unit 14 is formed in the cylindrical extending portion (inner fixing portion) 18a. The unit (optical reflection encoder module) 22 is fixed. Similarly, the outer ring (second bearing ring) 24 of the cross roller bearing 16 is also formed in a cylindrical shape at one end, and the motor drive magnet (rotor) 26 of the motor unit 12 is formed in the extended portion (outer fixed portion) 24a.
And a seal with slit 2 in which the slit disk of the rotary encoder of the detection unit 14 and the seal of the bearing are integrated.
8 is fixed. In addition, a separator that maintains the roller interval of the rolling elements is provided between the bearing rings of the cross roller bearing 16.

In the motor section 12, the stator 20 and the motor drive magnet 26 are arranged so as to face each other, and
The second bearing ring 24 is rotationally driven by receiving a signal and electric power from a motor driving driver (not shown). Motor characteristics are improved if the inner ring and outer ring are made of magnetic material and used as a magnetic circuit member, but stray due to the formation of a magnetic circuit of the motor by making any of the inner ring, outer ring, or rolling element a non-magnetic material. Stray current corrosion;
The effect of preventing the occurrence of (electrolytic corrosion) is obtained. This allows
The life of the bearing is extended, and stable rotational movement can be maintained for a long period of time. Further, in order to secure the bearing performance and prevent the occurrence of electrolytic corrosion, it is effective to form the rolling elements with a ceramic material. This is effective not only for preventing electrolytic corrosion, but also for improving the rotational performance of the bearing itself and increasing the rigidity of the bearing.

The detection unit 14 detects the rotation angle, the rotation speed, etc. in a non-contact manner, and as described above, the annular slit seal 28 having a plurality of openings formed on the circumference and the slit seal. An optical reflection type encoder module 22 having a light source and a light receiving portion, which is provided at a predetermined position on the circumference facing the opening of 28, and has a slit seal 2
8 and the encoder module 22 detect the rotation angle, the rotation speed, etc. based on the pulse signal generated by the relative movement of the second bearing ring 24 by the rotation operation of the second bearing ring 24. Since the slit-attached seal 28 is provided at the end portion in the axial direction, it also functions as a seal that prevents the adhesion of dust. The encoder module 22 is attached to one surface of a fixing ring member 23 fixed to the outer peripheral surface of the extension portion 18a of the first bearing ring 18.

As described above, according to the rolling bearing 100 with a built-in motor of this embodiment, the motor portion 12 and the detecting portion 14 are substantially housed inside the bearing, which simplifies the construction of the bearing and greatly Compactness can be achieved and cost can be reduced. Roller bearing with built-in motor 10
The assembling accuracy of 0 itself can be improved, and the rotary shaft can be attached to the second bearing ring 24 of the rolling bearing 100 with a built-in motor with the same high accuracy as the finishing accuracy of the bearing portion 10. In addition, this mounting work is also easy. Further, since a large installation space is not required inside the rolling bearing 100 with a built-in motor, the bearing inner diameter of the rolling bearing 100 with a built-in motor can be designed to be large, and the difference from the outer diameter of the bearing can be reduced to further reduce the thickness. Become.

Also, an extension portion 18a of the first bearing ring 18 is provided.
Is integrally formed with the inner ring of the bearing portion 10, and the extension portion 24a of the second bearing ring 24 is integrally formed with the outer ring of the bearing portion 10, so that the structure of the bearing can be simplified and rattling due to resonance can be prevented. Occurrence can be reduced by a minor design change, and vibration characteristics can be improved. Furthermore, by matching the inner diameter of the first bearing ring 18 with the bearing inner diameter of the bearing portion 10 and matching the outer diameter of the second bearing ring 24 with the bearing outer diameter, the motor-integrated bearing 100 can be used as one rolling bearing. Can be shaped. As a result, the rotating shaft, the housing, the hub, etc. to be connected can be supported more reliably and stably. Further, the slit disk of the detection unit 14 is a seal with a slit that can also function as a seal, so that the configuration can be simplified and the cost can be further reduced.

Next, a modified example of this embodiment will be described. 2A and 2B are views showing a configuration of a modified example of the rolling bearing 100 with a built-in motor according to the present embodiment, wherein FIG. 2A is a sectional view and FIG. 2B is a side view showing a partial section. Hereinafter, the members having the same functions as those in the first embodiment described above will be denoted by the same reference numerals, and the description thereof will be omitted. The rolling bearing 200 with a built-in motor according to the present modification includes the second bearing ring 24.
Is the stationary side and the first bearing ring 18 is the rotating side. Therefore, regarding the motor unit 12, the stator 20
Is fixed to the second bearing ring 24, and the motor drive magnet 26 is fixed to the first bearing ring 18, and for the detection unit 14, the fixing ring member 23 to which the encoder module 22 is attached is attached to the second bearing ring 24. In addition, the configuration is similar to that of the first embodiment except that the slit seals 28 are fixed to the first bearing rings 18, respectively.

According to this structure, the rotary shaft can be attached to the first bearing ring 18 of the rolling bearing 200 with a built-in motor with high accuracy close to the finish accuracy of the bearing portion 10, and the same effect as described above can be obtained. Played.

Next, a second embodiment of the rolling bearing with a built-in motor according to the present invention will be described with reference to FIGS. 3A and 3B are views showing a configuration of a second embodiment of a roller bearing with a built-in motor according to the present invention, wherein FIG. 3A is a sectional view and FIG. 3B is a side view showing a partial section. The rolling bearing 300 with a built-in motor of the present embodiment increases the motor output by increasing the volume of the stator 34 of the motor unit 12. That is, the first bearing ring 36 has a smaller bearing inner diameter to increase the space between the cylindrical extension portion 36a and the second bearing ring 24, thereby increasing the size of the installable stator 34. There is. Along with this, in the detection unit 14, the inner diameter of the fixing ring member 38 to which the encoder module 22 is fixed is reduced, and the inner diameter of the slit seal 40 is also reduced. Roller bearing 3 with a built-in motor of this embodiment
According to the configuration of No. 00, by increasing the size of the stator 34, the magnetic flux that can be generated can be increased, a stronger magnetic force can be obtained, and a high-output motor with enhanced rotational driving force can be formed.

FIG. 4 is a diagram showing a modified example of the rolling bearing with a built-in motor according to the present embodiment. FIG. 4A is a sectional view and FIG. 4B is a side view showing a partial section. The rolling bearing 400 with a built-in motor of the present modification is configured such that the second bearing ring 24 is the fixed side and the first bearing ring 36 is the rotating side. Therefore, for the motor unit 12, the stator 34
Is fixed to the second bearing ring 24, and the motor drive magnet 26 is fixed to the first bearing ring 36. For the detector 14, the fixing ring member 38 to which the encoder module 22 is attached is attached to the second bearing ring 24. In addition, the configuration is the same as that of the second embodiment except that the slit seals 28 are fixed to the first bearing rings 36, respectively. According to this configuration, with high accuracy close to the finishing accuracy of the bearing unit 10,
The rotary shaft can be attached to the first bearing ring 36, and the same effects as the above can be obtained.

Next, a third embodiment of the rolling bearing with a built-in motor according to the present invention will be described with reference to FIGS. 5 and 6. 5A and 5B are views showing the configuration of a third embodiment of a roller bearing with a built-in motor according to the present invention, wherein FIG. 5A is a sectional view and FIG. 5B is a side view showing a partial section. In the rolling bearing 500 with a built-in motor according to the present embodiment, the cylindrical inner fixing portion 48 and outer cylindrical fixing portion 50 to which the motor portion 12 and the detecting portion 14 are fixed are formed separately from the bearing portion 10. It is connected to one side surface of the inner ring (first race ring) 44 and the outer ring (second race ring) 46. A stepped portion 44 a is formed on the inner peripheral side of the one end surface of the inner ring 44 on the motor portion 12 side.
The inner fixing portion 48 is fixed to 4a by interference fitting or adhesion. Similarly, a stepped portion 46a is formed on the outer peripheral side of the one end surface of the outer ring 46 on the motor portion 12 side, and the outer fixing portion 50 is fixed to the stepped portion 46a. The inner fixing portion 48 fixes the stator 20 of the motor portion 12 and the encoder module 22 of the detecting portion 14. In addition, the outer fixed portion 50 is the motor drive magnet 2 of the motor portion 12.
6 and a seal 28 with a slit in which the slit disk of the rotary encoder of the detection unit 14 and the seal of the bearing are integrated.

Rolling bearing 500 with a built-in motor having the above construction
According to this, the bearing unit 10, the motor unit 12, and the detection unit 14
By separately forming and, the structures of the inner ring 44 and the outer ring 46 can be simplified, and the outer ring bearing portion 10 and
It is possible to adopt an assembling method in which the motor unit 12 and the detecting unit 14 are individually assembled, and then both are assembled, and the assembling process can be simplified as compared with the case where the bearing unit 10 is integrally formed. Further, by constructing both of them so that they can be disassembled, maintenance of the rolling bearing 500 with a built-in motor becomes easy. Here, by forming at least one of the inner fixing member 48 and the outer fixing member 50 from a nonmagnetic material such as austenitic stainless steel, the occurrence of electrolytic corrosion can be prevented. In this case, for the inner ring / outer ring / rolling element of the bearing, high hardness bearing steel such as bearing steel or martensitic stainless steel can be used. The inner ring 44 and the inner ring fixing portion 48,
Alternatively, only one of the outer ring 46 and the outer ring fixing portion 50 may be configured as a separate body, and the above effect is exhibited on the side of the separate body.

6A and 6B are views showing the structure of a modification of the rolling bearing with a built-in motor according to the present embodiment, wherein FIG. 6A is a sectional view and FIG. 6B is a side view showing a partial section. The rolling bearing 600 with a built-in motor of the present modification has the outer ring 46 fixed side,
The inner ring 44 is configured on the rotating side. Therefore, in the motor section 12, the stator 20 is fixed to the outer fixing member 50 connected to the outer ring 46, and the motor drive magnet 26 is fixed to the inner fixing member 48 connected to the inner ring 44.
Regarding the detection unit 14, the fixing ring member 23 to which the encoder module 22 is attached is attached to the outer fixing member 50.
In addition, except that the slit disks 28 are fixed to the inner fixing members 48, respectively, the configuration is the same as that of the third embodiment. With this configuration, the same effect as described above can be obtained.

FIG. 7 is a sectional view of a rolling bearing 700 with a built-in motor according to the fourth embodiment. In the rolling bearing 700 with a built-in motor according to this embodiment, the ball bearing 80 is used for the bearing portion 10. The ball bearing 80 is an inner ring (first bearing ring) 60.
And a plurality of rolling elements (balls) 51 interposed between the outer ring (second race ring) 70 and a cage 52 for holding the rolling elements 51.
And have. Further, the bearing portion 10 is provided with seal members 53 on both axial sides of the rolling element 51. The seal member 53 on one side (right side in the figure) is arranged between the motor unit 12 and the rolling element 51. The seal groove 70b for mounting the seal member 53 is provided on the rolling element 5 of the outer ring 70.
The outer ring 70 is formed along the inner peripheral surface of the outer ring 70 on both sides in the axial direction of the portion where the first ring 1 contacts. The seal member 53 attached to the seal groove 70b extends and contacts the step portion 60b formed on the outer peripheral surface of the inner ring 60. That is, the seal member 5
3 seals the rolling element 51, the cage 52 and the raceway from the outside in the space between the inner ring 60 and the outer ring 70, and the seal member 53 seals the rolling contact portion.

In this embodiment, the outer ring 70 is on the rotating side and the inner ring 6 is
0 is configured as the fixed side. Therefore, the motor unit 1
2, the rotor 26 is attached to the outer ring 70 and the stator 20 is attached.
Are fixed to the inner ring 60, respectively. Here, as the rotor 26, a rotor in which a permanent magnet is adhered and fixed to the inner circumference of a ring-shaped member (mild steel ring) 29 formed of a mild steel material is used. The mild steel ring 29 is fitted inside the extended portion 70 a of the outer ring 70. In addition, the stator 20
Is formed by winding a coil around the outer peripheral surface of the extension portion 60a of the inner ring 60. In the present embodiment, the stator 20
The rotor 26 does not project from the space between the extended portion (inner fixed portion) 60a of the inner ring 60 and the extended portion (outer fixed portion) 70a of the outer ring 70, both in the radial direction and in the axial direction. .

As the inner ring 60 and the outer ring 70, JIS
A material obtained by quenching and hardening SUJ2 material can be used. In this case, the cost is lower than that of a non-magnetic material such as ceramics, so that the cost can be reduced. From the viewpoint of preventing the occurrence of electrolytic corrosion, the rolling element 51
Ceramics such as silicon nitride and zirconia are used as the material. As a material of the cage 52, a non-magnetic material such as polyamide resin or polyether sulfone resin is used.

Rolling bearing 700 with a built-in motor having the above structure
According to this, the assembly is easy and the cost is reduced.
Further, the rotation accuracy is high and the torque is low. The present embodiment is suitable for use in drive devices such as computer equipment and peripheral equipment.

FIG. 8 shows a sectional view of a rolling bearing 800 with a built-in motor according to the fifth embodiment. In the rolling bearing 800 with a built-in motor, the extended portion (outer fixed portion) 71a of the outer ring (second race ring) 71 is on the motor portion 12 side, and the extended portion (inner fixed portion) of the inner ring (first race ring) 60. It is shorter than 60a. That is, the axial dimension of the outer ring 71 is the inner ring 6
The extension portion 60a of the inner ring 60 is smaller than the extension portion 7 of the outer ring 71 on one side in the axial direction.
It projects from 1a in the axial direction. Although the seal members 53 are provided on both sides of the rolling element 51 in the axial direction, the extension portion 71a of the outer ring 71 is closer to the motor unit 12 than the seal member 53 disposed between the rolling element 51 and the motor unit 12. It ends slightly protruding.

Extension parts 60 of the inner ring 60 and the outer ring 71
A ring-shaped holding plate 55 is fixed to axial end portions of the a and 71a opposite to the bearing portion 10 side. Holding plate 5
5 is formed of, for example, a mild steel plate, and has an extended portion 60a,
It has a fixing surface 55a fixed to 71a and a flange surface 55b to which a rotor or a stator is attached, and has an L-shaped cross section. The fixing surface 55a is attached to one edge portion (outer peripheral edge portion or inner peripheral edge portion) of the ring-shaped flange surface 55b.
It is integrally formed perpendicular to the flange surface 55b.

At the axial end of the outer peripheral surface of the extension portion 71a of the outer ring 71, the cylindrical fixing surface 55a of the one holding plate 55 is formed.
Is fitted. Flange surface 55b of the holding plate 55
Extend vertically toward the inner ring 60. The axial end surface of the extension portion 71a of the outer ring 71 is in contact with the flange surface 55b. The stator 20 is provided on the flange surface 55b on the side opposite to the bearing portion 10 side.
In the present embodiment, it can be said that the stator unit in which the stator 20 is provided on the holding plate 55 is externally fitted to the outer diameter surface of the outer ring 71. Then, the extension portion 6 of the inner ring 60
The fixing surface 55a of the other holding plate 55 is externally fitted to the axial end portion of the outer peripheral surface of 0a. The flange surface 55b of the holding plate 55 extends vertically toward the outer ring 71. The rotor 26 is attached to the bearing surface 10 side of the flange surface 55b. The rotor 26 faces the stator 20 as viewed in the axial direction. Extension 60 of inner ring 60
The axial end surface of a and the surface of the flange surface 55b opposite to the bearing portion 10 side are substantially flush with each other.

In the present embodiment, the stator 20 and the rotor 26 are such that the outer peripheral surface of the extended portion (inner fixed portion) 60a of the inner ring 60 and the outer peripheral surface of the extended portion (outer fixed portion) 71a of the outer ring 71 are viewed in the radial direction. It fits in between. Even in such a case, in the present specification, it is assumed that the stator 20 and the rotor 26 are arranged between the outer fixed portion and the inner fixed portion when viewed in the radial direction. When viewed in the axial direction, the stator 20 and the rotor 26 are fitted between the axial end portion of the extension portion 60 a of the inner ring 60 and the axial end portion of the extension portion 71 a of the outer ring 71.

In this embodiment, the inner ring 60 is on the rotating side and the outer ring 7 is
1 is configured as a fixed side. Here, the stator 20
The coil is printed on the flange surface 55b of the holding plate 55. The rotor 26 is provided with a multi-pole magnet on the flange surface 55b of the holding plate 55.

Rolling bearing 800 with a built-in motor having the above structure
According to the above, it is possible to assemble the motor unit 12 after assembling the bearing unit 10 in the manufacturing process. Therefore, the assembly is easy and the cost is reduced. In addition, maintenance of the motor unit 12 can be easily performed. The present embodiment is suitable for use in drive devices such as computer equipment and peripheral equipment.

FIG. 9 is a sectional view of a rolling bearing 900 with a built-in motor according to the sixth embodiment. In the rolling bearing 900 with a built-in motor, the configuration of the motor portion 12 is substantially the same as that of the fifth embodiment described above. In the present embodiment, a flange portion 72c extending outward in the radial direction is integrally formed with the outer ring 72 at the axial end portion of the bearing portion 10 opposite to the motor portion 12 side. The ring-shaped flange portion 72c is provided with a plurality of through holes 73 that are open at equal intervals on the circumference. The outer ring 72 is fixed to a rotating member (not shown) arranged so as to face the flange portion 72c by a fixing means such as a bolt inserted into the through hole 73. In this way, the outer ring 72 is rotated integrally with the rotating member.

The inner ring 61 in this embodiment is closed by an end wall 61c having a disk-shaped inner ring inner diameter at the axial end opposite to the motor portion 12 side. An end wall 61c integrally formed with the inner ring 61 is provided with a screw hole 62 penetrating its central portion. The inner ring 61 is fixed to a fixing member (not shown) arranged so as to face the end wall 61c by a male screw screwed into the screw hole 62.

Rolling bearing 900 with a built-in motor having the above structure
According to the above, since the rotating member (not shown) and the outer ring 72 are flange-coupled, or the fixing member (not shown) and the inner ring 61 are screw-coupled, it is possible to avoid a problem such as creep on each fitting surface. You can The present embodiment is suitable for use in drive devices such as computer equipment and peripheral equipment. Although not shown, the inner ring 6
As a method for fixing 1 and the fixing member, another method such as spline connection may be used instead of screw connection.

The seal member 53 found in the above fourth to sixth embodiments can be omitted as appropriate. For example, it is possible to omit the seal member 53 of the rolling bearing with a built-in motor by providing sealing means on the side of the device on which the rolling bearing with a built-in motor is mounted, depending on the use environment.

FIG. 10 is a sectional view of the rolling bearing 1000 with a built-in motor according to the seventh embodiment. In the rolling bearing 1000 with a built-in motor according to the present embodiment, a cross ball bearing 66 is used for the bearing portion 10. The cross ball bearing 66 according to the present embodiment is provided between the pair of bearing rings (the inner and outer rings 64,
(Between 74), a plurality of rolling elements 66a are incorporated, and each race has a raceway groove formed of a raceway surface having a diameter larger than the radius of the rolling body 66a. At least one bearing ring of the pair of bearing rings has two bearing surfaces. The outer diameter of each rolling element 66a, which is a rolling contact surface, also has a curvature in the axial direction. In this bearing, the outer diameters of the rolling elements 66a, which are alternately arranged on the circumference in an alternating manner, are always in contact with each other on the raceway surface of one of the opposing raceways and the raceway surface of the other raceway. It is a two-point contact bearing. Therefore, the bearing is preloaded, and one bearing can support the axial load, the radial load and the moment load. Here, the retainer 65 is used to support the rolling elements 66a so that they can roll. Here, the rolling element 66a of the present embodiment has a shape in which both pole portions of a ball having a single curvature are processed into a flat surface. It should be noted that the shape may be one in which the curvature changes instead of the single curvature.

In this embodiment, the outer ring 74 is formed by combining members each having one raceway surface. That is, the outer ring 74 has a dividable configuration. But,
The invention is not limited to this, and the inner ring 64 may be dividable. A sleeve can be fitted to the outer peripheral surface of the outer ring 74 or the inner peripheral surface of the inner ring 64 to more reliably prevent the races on the split side from separating.

In this embodiment, the outer ring 74 is arranged on the rotating side and the inner ring 64 is arranged on the fixed side. Therefore, in the motor unit 12, the stator 20 is provided on the outer peripheral surface of the extension portion (inner fixed portion) 64a of the inner ring 64, and the rotor 26 is provided on the outer ring 7.
They are fixed to the inner peripheral surfaces of the extended portions (outer fixed portions) 74a of No. 4 respectively. Here, as the permanent magnet used for the rotor 26, a ferrite magnet, an aluminum manganese magnet, an alnico magnet, or a rare earth magnet (Nd-Fe-B magnet or the like) can be used. Particularly, when a rare earth magnet is used, the energy product of the magnet is large, so that the generated torque of the motor can be increased with a small motor volume, which is preferable.
In the present embodiment, the stator 20 formed by winding a coil is arranged on the outer circumference of the inner fixed portion, and the rotor 26 made of a permanent magnet is arranged on the inner circumference of the outer fixed portion. However, the present invention is not limited to this, and for example, a permanent magnet may be used for the stator.

Rolling bearing 100 with a built-in motor having the above construction
According to 0, the contact area between the rolling element 66a and the rolling groove can be reduced, and the inner ring 64 and the outer ring 74 are relatively smoothly rotated with low torque. Further, it is possible to favorably support the axial load, the radial load and the moment load. Although not shown, a separator may be used instead of the retainer 65. This embodiment is suitable for use in driving devices such as computer equipment and peripheral equipment thereof, factory automation, driving robots, and the like.

The present invention is not limited to the above-mentioned embodiment, but can be appropriately modified and improved. It is also possible to combine the above embodiments. For example, the detectors used in the first to third embodiments may be applied to the fourth to seventh embodiments.

[0063]

According to the rolling bearing with a built-in motor according to the present invention, the motor part and the detecting part can be arranged substantially inside the bearing, and the simplification of the structure of the bearing and the drastic downsizing can be achieved. Assembling becomes easy, and the cost can be reduced. Furthermore, the accuracy of assembly of the rolling bearing with built-in motor itself is improved, and the rotating shaft, housing,
A hub or the like can be attached with the same high precision as the finished precision of the bearing portion. In addition, this mounting work is also easy.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a roller bearing with a built-in motor according to the present invention, in which (a) is a sectional view and (b) is a side view showing a partial section.

2A and 2B are diagrams showing a configuration of a modified example of the motorized rolling bearing according to the first embodiment, wherein FIG. 2A is a sectional view and FIG. 2B is a side view showing a partial section.

3A and 3B are views showing the configuration of a second embodiment of a roller bearing with a built-in motor according to the present invention, wherein FIG. 3A is a sectional view and FIG. 3B is a side view showing a partial section.

4A and 4B are views showing a configuration of a modified example of the rolling bearing with a built-in motor according to the second embodiment, wherein FIG. 4A is a sectional view and FIG. 4B is a side view showing a partial section.

5A and 5B are views showing the configuration of a third embodiment of a roller bearing with a built-in motor according to the present invention, in which FIG. 5A is a sectional view and FIG. 5B is a side view showing a partial cross section.

6A and 6B are diagrams showing a configuration of a modified example of the rolling bearing with a built-in motor according to the third embodiment, wherein FIG. 6A is a sectional view and FIG. 6B is a side view showing a partial section.

FIG. 7 is a cross-sectional view showing the configuration of a fourth embodiment of a motor-equipped rolling bearing according to the present invention.

FIG. 8 is a sectional view showing a configuration of a fifth embodiment of a roller bearing with a built-in motor according to the present invention.

FIG. 9 is a sectional view showing the configuration of a sixth embodiment of the motor-integrated rolling bearing according to the present invention.

FIG. 10 is a seventh embodiment of the roller bearing with a built-in motor according to the present invention.
It is sectional drawing which shows the structure of embodiment.

FIG. 11 is a diagram showing an example of a direct drive motor used in the field of conventional factory automation.

FIG. 12 is a diagram showing a configuration example of an exciting coil provided in a stator.

FIG. 13 is an explanatory diagram showing a rotation principle of a rotor.

FIG. 14 is a diagram showing another configuration example of a direct drive motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 bearing part 12 motor part 14 detection part 16 cross roller bearing 18 inner ring (first bearing ring) 18a extension part (inner fixing part) 20,34 stator 22 encoder module 23 fixing ring member 24 outer ring (second bearing ring) ) 24a Extended part (outer fixed part) 26 Motor drive magnet (rotor) 28, 40 Slit seal 36 First race ring 38 Fixing ring member 44 Inner ring 44a Stepped part 46 Outer ring 46a Stepped part 48 Inner fixed part 50 Outer fixed part 100, 200, 300, 400, 500, 600, 7
00,800,900,1000 Rolling bearing with built-in motor

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16C 33/62 F16C 33/62 33/78 33/78 Z 41/00 41/00 H02K 5/173 H02K 5/173 Z 11/00 11/00 BF term (reference) 3J016 AA01 AA02 AA03 BB17 CA08 3J101 AA03 AA13 AA26 AA32 AA33 AA42 AA54 AA62 BA10 BA53 BA54 BA73 EA02 EA06 EA36 CC01BB01 BB01 BB01BB19 GA01BB01BB19 GA01 BB15BB15A07 ABB02 DD09 EB10 EB12 GG04 5H611 AA01 BB01 BB06 BB10 PP07 QQ01 QQ03 RR04 UA04 UB01

Claims (12)

[Claims] 1. A rolling bearing with a built-in motor, comprising a bearing part having an inner ring, an outer ring, and a plurality of rolling elements, and a motor part having a stator and a rotor for relatively rotating and driving the inner ring and the outer ring of the bearing part. The bearing portion has a first bearing ring formed by coaxially forming a cylindrical inner fixing portion on one end surface of the inner ring, and a cylindrical outer fixing portion coaxially formed on one end surface of the outer ring. And a second bearing ring, which is formed between the inner fixing portion of the first bearing ring and the outer fixing portion of the second bearing ring when viewed in the radial direction. A rolling bearing with a built-in motor, characterized in that 2. The stator of the motor unit is fixed to the outer circumference of the inner fixing unit, and the rotor of the motor unit is fixed to the inner circumference of the outer fixing unit to fix the first bearing ring. 2. The rolling bearing with a built-in motor according to claim 1, wherein each of the raceways is driven to rotate relative to each other with the second raceway as a rotation side. 3. The rotor of the motor section is fixed to the outer circumference of the inner fixed section, and the stator of the motor section is fixed to the inner circumference of the outer fixed section to rotate the first bearing ring. 2. The rolling bearing with a built-in motor according to claim 1, wherein each of the raceways is driven to rotate relative to each other with the second raceway being a fixed side. 4. The axial end portion of the inner fixed portion projects in the axial direction from the axial end portion of the outer fixed portion, and when viewed in the axial direction, the axial end portion of the outer fixed portion and the inner side The rolling bearing with a built-in motor according to any one of claims 1 to 3, wherein at least a part of the stator and the rotor are arranged between the fixed portion and an end portion in the axial direction. 5. A detector for detecting rotation of the bearing,
The rolling bearing with a built-in motor according to any one of claims 1 to 4, wherein the rolling bearing is provided between the inner fixed portion and the outer fixed portion. 6. The detection unit has a slit disk attached to a rotation side and a light irradiation detection unit attached to a fixed side, and the slit disk is provided between the inner fixed section and the outer fixed section. At the end of the axial direction opposite to the bearing part, the light irradiation detection part is disposed so as to face the slit disk on the bearing part side in the axial direction of the slit disk. The rolling bearing with a built-in motor according to claim 5, wherein the rolling bearing has a built-in motor. 7. The motorized rolling bearing according to claim 1, wherein at least one of the inner fixed portion and the outer fixed portion is made of a non-magnetic material. 8. The motorized rolling bearing according to claim 1, wherein the inner fixing portion is formed separately from the inner ring. 9. The rolling bearing with a built-in motor according to claim 1, wherein the outer fixing portion is formed separately from the outer ring. 10. The bearing according to claim 1, wherein the bearing portion is a cross roller bearing.
Roller bearing with a built-in motor described in paragraph. 11. The rolling element according to claim 1, wherein the rolling element is made of a ceramic material.
Roller bearing with a built-in motor described in paragraph. 12. The bearing according to claim 1, wherein the bearing portion is a cross ball bearing.
Roller bearing with a built-in motor described in paragraph.