WO2022009249A1

WO2022009249A1 - Slip ring and electric motor

Info

Publication number: WO2022009249A1
Application number: PCT/JP2020/026316
Authority: WO
Inventors: 只好上原
Original assignee: 株式会社創; 株式会社アイエムアイ; ユー・ジー・ケイ株式会社
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2022-01-13
Also published as: JP6843365B1; JPWO2022009249A1

Abstract

[Problem] Provided are a slip ring in which wear due to rotation is reduced as much as possible and an electric motor equipped with the slip ring. [Solution] The slip ring 60a, 60b and electric motor 80a, 80b rotate, at a rotational speed of about a half of that of a rotating body 40, a differential rotation portion 74a, 74b that is a sliding portion. This reduces the virtual rotational speed of the sliding portion, thereby enabling the reduction in the wear of the sliding portion. Further, the slip ring 60a, 60b and the electric motor 80a, 80b position a sliding insulating portion 78 softer than a sliding conducting body 76a, 76b in the gap of the sliding conducting body 76a, 76b. This allows pressing force against the sliding conducting body 76a, 76b to be received on the sliding insulating portion 78 side, thereby enabling the reduction in the pressing force acting on the sliding conducting body 76a, 76b. This makes it possible to further reduce the wear of the sliding conducting body 76a, 76b, a rotating body electrode 62, and a fixed electrode 64.

Description

Slip rings and motors

The present invention relates to a slip ring that reduces wear due to rotation as much as possible and an electric motor provided with the slip ring.

In recent years, from the viewpoint of reducing carbon dioxide emissions, the spread of hybrid vehicles and electric vehicles that use both internal combustion engines and electric motors has been remarkable. Such hybrid vehicles and electric vehicles have a high-power electric motor (motor) that rotates wheels by electric power as a drive source. Therefore, higher efficiency and higher output are required for these motors. Here, the inventors of the present application have made the invention described in the following [Patent Document 1], which enables high output by rotating the stator of the electric motor and using the rotational force of the stator for the rotation of the rotor.

International Publication No. 2020/07534 Pamphlet

However, in the motor described in [Patent Document 1], the stator also rotates. Therefore, in order to pass the drive current through the coil of the rotating stator, it is necessary to use a slip ring that maintains an electrical connection to the rotating body. However, especially in an electric motor for an automobile, the number of rotations of the rotating body is high, so that there is a problem that the sliding portion of the slip ring is heavily worn. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a slip ring in which wear due to rotation is reduced as much as possible and an electric motor provided with the slip ring.

The present invention
(1) A rotating body electrode 62 provided on the rotating body 40 side, a fixed electrode 64 provided on the fixed body 12 side, a bearing 70 for rotatably holding the rotating body 40, and the bearing 70 are configured. Difference between a rolling element 706 that self-revolves with the rotation of the rotating body 40, a transmission member 72 that transmits the revolving motion of the rolling element 706, and a transmission member 72 that is connected to the transmission member 72 and rotates due to the revolving motion of the rolling element 706. With the dynamic rotating

portions

74a and 74b and the

sliding conductors

76a and 76b provided on the differential rotating

portions

74a and 74b, the rotating body electrode 62 abuts on one surface and the fixed electrode 64 abuts on the other surface. Provided are a

slip ring

60a, 60b having an elastic member 66 for pressing the rotating body electrode 62 or the fixed electrode 64 toward the differential rotating

portions

74a, 74b with a predetermined force. To solve the above problems.
(2) The sliding insulating portion 78 is located between the

sliding conductors

76a and 76b, and the sliding insulating portion 78 is deformed in the elastic region of elasto-plastic deformation and pushed to the

sliding conductors

76a and 76b. The slip according to (1) above, wherein the pressure is reduced and the

sliding conductors

76a and 76b, the rotating body electrode 62 and the fixed electrode 64 are contact-conducted in a critical contact state where the pressing force is extremely small. The above problems are solved by providing the

rings

60a and 60b.
(3) The differential rotation portion 74a has a disk shape, and the sliding conductor 76a has an arcuate end face and is arranged in a circular shape concentric with the differential rotation portion 74a, and both ends of the sliding conductor 76a are further arranged. The surfaces are exposed flush with each other on both planes of the differential rotation portion 74a.
The slip ring according to (2) above, wherein the rotating body electrode 62 and the fixed electrode 64 form a ring shape concentric with the differential rotating portion 74a and having a radius substantially the same as that of the sliding conductor 76a. By providing 60a, the above problem is solved.
(4) The sliding conductor 76a is made of a conductive carbon plate, and has a noble metal thin film on the contact surface between the rotating body electrode 62 and the sliding conductor 76a of the fixed electrode 64. 3) The above problem is solved by providing the slip ring 60a described above.
(5) The differential rotating portion 74b has a cylindrical shape, and the sliding conductor 76b has an arch shape having the same curvature as the differential rotating portion 74b and makes one round in the circumferential direction. Further, the inner peripheral surface and the outer peripheral surface of the sliding conductor 76b are flush with the inner peripheral surface and the outer peripheral surface of the differential rotating portion 74b, and the rotating body electrode 62 has an outer peripheral surface. The fixed electrode 64 has an arch shape having substantially the same curvature as the inner peripheral surface of the sliding conductor 76b, and the fixed electrode 64 has an arch shape in which the inner peripheral surface has substantially the same curvature as the outer peripheral surface of the sliding conductor 76b. The outer peripheral surface of the rotating body electrode 62 is in contact with the inner peripheral surface of the sliding conductor 76b, and the inner peripheral surface of the fixed electrode 64 is in contact with the outer peripheral surface of the sliding conductor 76b to conduct conduction. The above problem is solved by providing the slip ring 60b according to the above (2), which is a feature.
(6) The above-mentioned (5), wherein the sliding conductor 76b is made of a carbon plate having conductivity, and has a noble metal thin film on the outer peripheral surface of the rotating body electrode 62 and the inner peripheral surface of the fixed electrode 64. The above problem is solved by providing the slip ring 60b of the above.
(7) An output shaft 10 that transmits a rotational force to the driven body M, a rotor 30 fixed to the output shaft 10, a stator 40 located outside the rotor 30, the output shaft 10 and the stator 40. A fixed bearing portion 12 that rotatably supports the rotor 30, a plurality of coils 42 provided on the stator 40 to rotate the rotor 30 by flowing a drive current, and the stator 40 to rotate in the same direction as the rotor 30. It has a stator rotation mechanism 46 that can be held, and
When the rotation of the rotor 30 is decelerated, the rotational force of the rotor 30 is converted into the rotation of the stator 40, and the driving current is passed in the state where the stator 40 is rotated, so that the rotational force due to the driving current is obtained. In the electric motor that rotates the rotor 30 by applying the rotational force of the stator 40,
The coil 42 is provided between the stator 40 as a rotating body (40) and the fixed bearing portion 12 as a fixed body (12), and supplies a drive current from the fixed bearing portion 12 side to the coil 42. ) To 80b, which further comprises the

slip rings

60a and 60b according to any one of (6) above, thereby solving the above-mentioned problems.

In the slip ring and the electric motor according to the present invention, the differential rotating portion, which is a sliding portion, is rotated at about 1/2 the rotation speed of the rotating body. As a result, the rotation speed of the sliding portion is reduced, and wear of the sliding portion can be reduced. Further, in the slip ring and the electric motor according to the present invention, a sliding insulating portion softer than the sliding conductor is positioned between the sliding conductors. As a result, the pressing force on the sliding conductor is received by the sliding insulating portion side, and the pressing force applied to the sliding conductor can be reduced. This makes it possible to further reduce the wear of the sliding conductor, the rotating body electrode, and the fixed electrode.

It is a schematic cross-sectional view of the slip ring of the 1st aspect which concerns on this invention. It is an exploded view of the sliding part of the slip ring of the 1st aspect which concerns on this invention. It is a schematic cross-sectional view of the slip ring of the 2nd aspect which concerns on this invention. It is a schematic XX sectional view of the slip ring of the 2nd aspect which concerns on this invention. It is an exploded perspective view of the sliding part of the slip ring of the 2nd aspect which concerns on this invention. It is a figure explaining the structure of a general bearing. It is a schematic cross-sectional view of the electric motor of the 1st aspect which concerns on this invention. It is a schematic cross-sectional view of the electric motor of the 2nd aspect which concerns on this invention. It is a figure which shows the NT diagram and the change of the rotation speed of the electric motor which concerns on this invention schematically.

An embodiment of a slip ring according to the present invention and an electric motor provided with the slip ring will be described with reference to the drawings. Here, FIG. 1 is a schematic cross-sectional view of the slip ring 60a according to the first aspect of the present invention. 2A and 2B are exploded views of the sliding portion of the slip ring 60a of the first embodiment, FIG. 2A is a diagram showing the rotating body electrode 62 side, and FIG. 2B is a differential rotating portion. It is a figure which shows 74a, and FIG. 2C is a figure which shows the fixed electrode 64 side. Further, FIG. 3 is a schematic cross-sectional view in the lateral direction of the slip ring 60b according to the second aspect of the present invention, and FIG. 4 is a schematic cross-sectional view taken along the line XX in FIG. Further, FIG. 5 is a schematic exploded perspective view of the sliding portion of the slip ring 60b of the second embodiment. The wiring of the

slip rings

60a and 60b to the rotating body electrode 62 and the fixed electrode 64 is shown only in FIGS. 1 and 3, and is omitted in other drawings. Further, here, a three-

pole slip ring

60a, 60b in which three sets of a rotating body electrode 62, a fixed electrode 64, and a

sliding conductor

76a, 76b are provided will be described as an example, but the

slip rings

60a, 60b will be described. The number of poles is not particularly limited and may be any number.

First, a configuration common to the

slip rings

60a and 60b according to the present invention will be described. The slip rings 60a and 60b according to the present invention shown in FIGS. 1 to 4 rotate the rotating body electrode 62 provided on the rotating body 40 side, the fixed electrode 64 provided on the fixed body 12 side, and the rotating body 40. A bearing 70 that can be held, a rolling element 706 that constitutes the bearing 70 and self-revolves with the rotation of the rotating body 40, a transmission member 72 that transmits the revolving motion of the rolling element 706, and the transmission member 72. The differential

rotating portions

74a and 74b that are connected and rotate by the revolving motion of the rolling element 706, and the rotating body electrode 62 provided on the differential rotating unit 74 and abutting on one surface and the fixed electrode 64 abut on the other surface. It has sliding

conductors

76a and 76b, and an elastic member 66 that presses the rotating body electrode 62 or the fixed electrode 64 toward the differential

rotating portions

74a and 74b with a predetermined force. The elastic member 66 may be provided on the rotating body 40 side to press the rotating body electrode 62, but from the viewpoint of stability, it is preferable to provide the elastic member 66 on the fixed body 12 side and press the fixed electrode 64. Further, elastic members 66 may be provided on both the rotating body electrode 62 and the fixed electrode 64, and the sliding

conductors

76a and 76b may be pressed from both sides.

Next, the bearing 70 of the

slip rings

60a and 60b and the transmission member 72 will be described. First, as shown in FIG. 6, a general bearing 70 has an inner ring 702 and an outer ring 704, and a plurality of rolling elements 706 are rotatably inserted between the inner ring 702 and the outer ring 704. Further, the general bearing 70 has a cage 708 (retainer) that keeps the rolling elements 706 at regular intervals so as not to come into contact with each other. Here, for example, when the inner ring 702 rotates, the rolling element 706 rotates and at the same time revolves around the axis of the bearing 70. Then, the revolving motion of the rolling element 706 causes the cage 708 to rotate about the axis of the bearing 70. The transmission member 72 of the present invention connects, for example, the cage 708 and the

differential rotation portions

74a and 74b, and rotates the

differential rotation portions

74a and 74b by the revolution motion of the rolling element 706. In the general bearing 70, the rotation speed of the revolving motion of the rolling element 706 (the rotation speed of the cage 708) is about ½ of the rotation speed on the rotation side. That is, in the

slip rings

60a and 60b of the present invention, the rotation speed of the

differential rotation portions

74a and 74b is about ½ of the rotation speed of the rotating body 40.

Here, in the conventional slip ring, since the sliding portion rotates at the rotation speed of the rotating body 40, if the rotation speed of the rotating body 40 is large (the rotation speed is high), the wear of the sliding portion progresses accordingly. In this respect, in the

slip rings

60a and 60b according to the present invention, the rotation speed of the differential

rotating portions

74a and 74b, which are sliding portions, is about ½ of that of the rotating body 40. Therefore, it is possible to reduce the wear of the sliding portion as compared with the conventional slip ring.

Next, the

differential rotation units

74a and 74b will be described. First, the differential rotation portion 74a of the slip ring 60a of the first embodiment has a disk shape as shown in FIG. 2 (b). When the rotating shaft of the rotating body 40 can penetrate outward through the slip ring 60a, a through hole 102 having a diameter larger than that of the rotating shaft may be provided at the center of the differential rotating portion 74a. Further, the sliding conductor 76a of the differential rotation portion 74a has an arcuate shape at both ends and has the same arc pillar shape as the thickness of the differential rotation portion 74a, and is installed in a circular shape concentric with the differential rotation portion 74a. Will be done. Then, a plurality of (four in this example) sliding conductors 76a forming one concentric circle form a one-pole sliding electrode. As a method of fixing the sliding conductor 76a, an electrode hole having the same shape as the sliding conductor 76a is formed in the differential rotating portion 74a, and the sliding conductor 76a is fitted into the electrode hole and installed. preferable. At this time, since the sliding conductor 76a has the same thickness as the differential rotating portion 74a, both end faces of the sliding conductor 76a are exposed flush with each other on both planes of the differential rotating portion 74a without any step.

Further, the differential rotation portion 74b of the slip ring 60b of the second form has a cylindrical shape as shown in FIG. The sliding conductor 76b provided in the differential rotation portion 74b has an arch shape having the same curvature as the differential rotation portion 74b and has the same thickness as the differential rotation portion 74b, and has the same thickness as the differential rotation portion 74b. Is installed so as to make one round in the circumferential direction. Then, a plurality of (four in this example) sliding conductors 76b that make one round in the circumferential direction form a one-pole sliding electrode. As a method of fixing the sliding conductor 76b, an electrode hole having the same shape as the sliding conductor 76b and penetrating from the inner peripheral surface to the outer peripheral surface is drilled in the differential rotating portion 74b so as to make one round in the circumferential direction. It is preferable to insert the sliding conductor 76b into the electrode hole and install it. As a result, the inner peripheral surface and the outer peripheral surface of the sliding conductor 76b are exposed flush with each other on the inner peripheral surface and the outer peripheral surface of the differential rotating portion 74b without any step.

Although an example in which four sliding

conductors

76a and 76b form a one-pole sliding electrode is shown here, the number of the sliding

conductors

76a and 76b is not particularly limited and two. Any number may be used, such as 3 or 6. The portion located between the plurality of sliding

conductors

76a and 76b and on the track of the rotating body electrode 62 and the fixed electrode 64 is the sliding insulating portion 78. In addition, in FIGS. 2B and 5, the positions of the sliding

conductors

76a and 76b are aligned and the sliding insulating portions 78 are arranged in a row, but the positions of the sliding

conductors

76a and 76b are aligned with each pole. The sliding insulating portions 78 may be positioned at different positions.

The sliding

conductors

76a and 76b are harder than the sliding insulating portion 78, for example ^{, a member having a pressing force of 0.5 kg / cm 2} or less and a wear amount of almost zero is used. Further, as the sliding

conductors

76a and 76b, members that are less likely to cause electrical corrosion (hereinafter referred to as electrolytic corrosion) caused by energization are used. As the material of such sliding

conductors

76a and 76b, it is particularly preferable to use a conductive carbon plate (conductive carbon).

Further, the sliding insulating portion 78 uses a member having a certain degree of hardness but being softer than the sliding

conductors

76a and 76b. As such a material, it is particularly preferable to use a cloth-based phenol resin laminated board (baklite board). Then, when the elastic member 66 ^{presses the fixed electrode 64 against the differential rotating portions 74a and 74b with a pressing force of, for example, 0.5 kg / cm 2} , the sliding insulating portion 78 receives this pressing force and the elastic region of elasto-plastic deformation. It is slightly deformed by, and it receives most of the pressing force and relieves it. As a result, the pressing force applied to the sliding

conductors

76a and 76b is reduced, and the sliding

conductors

76a and 76b are in a critical contact state where the pressing force is extremely small (a state in which contact conduction is performed with almost no pressing force applied). Contact and conduct with the rotating body electrode 62 and the fixed electrode 64. As a result, wear of the sliding

conductors

76a and 76b, the rotating body electrode 62, and the fixed electrode 64 can be reduced.

Next, the rotating body electrode 62 and the fixed electrode 64 of the slip ring 60a of the first embodiment will be described. As shown in FIGS. 2A and 2C, the rotating body electrode 62 and the fixed electrode 64 of the slip ring 60a of the first embodiment are concentric with the differential rotating portion 74a and have a radius (arc) of the sliding conductor 76a. It has a ring shape having substantially the same radius as the radius of). Then, as shown in FIG. 1, the elastic member 66 presses the fixed electrode 64 from the back surface side to the differential rotation portion 74a side with a predetermined pressure. This predetermined pressure is a pressure at which the sliding conductor 76a, the rotating body electrode 62, and the fixed electrode 64 are in contact with each other in a critical contact state. As a result, the surface of the rotating body electrode 62 on the differential rotating portion 74a side and one end surface of the sliding conductor 76a are contact-conducted in a critical contact state. Further, the surface of the fixed electrode 64 on the differential rotation portion 74a side and the other end surface of the sliding conductor 76a are contact-conducted in a critical contact state.

Next, the rotating body electrode 62 and the fixed electrode 64 of the slip ring 60b of the second form will be described. First, as shown in FIGS. 4 and 5, the rotating body electrode 62 of the slip ring 60b of the second form has an arch shape in which the outer peripheral surface has the same curvature as the inner peripheral surface of the sliding conductor 76b. Further, the fixed electrode 64 has an arch shape in which the inner peripheral surface has the same curvature as the outer peripheral surface of the sliding conductor 76b. Then, the rotating body electrode 62 is inserted into the cylindrical differential rotating portion 74b, and the fixed electrode 64 is arranged on the outer periphery of the differential rotating portion 74b. Then, the elastic member 66 presses the fixed electrode 64 from the outer peripheral side to the differential rotating portion 74a side on the inner peripheral side with a predetermined pressure. Further, at this time, an elastic member may be provided on the rotating body electrode 62 side as well, and the rotating body electrode 62 may be pressed from the inner peripheral side to the differential rotating portion 74a side on the outer peripheral side with a predetermined pressure. The predetermined pressure is a pressure at which the sliding conductor 76b, the rotating body electrode 62, and the fixed electrode 64 are in contact with each other in a critical contact state. As a result, the outer peripheral surface of the rotating body electrode 62 is in contact with the inner peripheral surface of the sliding conductor 76b in a critical contact state, and the outer peripheral surface of the sliding conductor 76b is in critical contact with the inner peripheral surface of the fixed electrode 64, respectively. Contact conduction in the state.

Further, on the contact surface of the rotating body electrode 62 and the fixed electrode 64 with the sliding

conductors

76a and 76b, that is, on the slip ring 60a, the differential rotating portion 74a of the rotating body electrode 62 indicated by the dots in FIG. 2A. The plane on the side and the plane on the differential rotating portion 74a side of the fixed electrode 64 shown by dots in FIG. 2C, and the outer peripheral surface of the rotating body electrode 62 and the fixed electrode 64 shown by dots in FIG. 5 in the slip ring 60b. It is preferable to provide a thin film of a noble metal that is difficult to ionize on the inner peripheral surface of the above by a well-known method such as plating or vapor deposition. As the material for this thin film, it is particularly preferable to use silver, which is inexpensive, has high conductivity, and has a relatively high hardness. In this configuration, the noble metal thin film with low electrical resistance disperses the current density on the contact surface with the sliding

conductors

76a and 76b, and the presence of the noble metal thin film that is difficult to ionize prevents electrolytic corrosion on the contact surface. Therefore, the wear of the rotating body electrode 62 and the fixed electrode 64 can be further reduced.

Here, the rotating body electrode 62 is applied to the differential rotating portion 74a (sliding conductor 76a: carbon plate, sliding insulating portion 78: bakelite plate) of the slip ring 60a of the first embodiment at a pressing force of 0.5 kg / cm ^2. When the fixed electrode 64 was contact-conducted and the differential rotating portion 74a was rotated for 1000 hr at about 3000 rpm, the amount of wear of the sliding

conductors

76a and 76b was 5 μm or less, and almost no wear was observed. Further, the resistance value between the rotating body electrode 62 and the fixed electrode 64 sandwiching the sliding conductor 76a was 10 mΩ or less when the differential rotating portion 74a was stopped, and was maintained at 100 mΩ or less even when the differential rotating portion 74a was rotated.

Next, the operation of the

slip rings

60a and 60b according to the present invention will be described. First, the rotating body electrode 62 and the fixed electrode 64 are conductive via the sliding

conductors

76a and 76b provided in the differential

rotating portions

74a and 74b. As a result, the rotating body 40 and the fixed body 12 are electrically connected to each other, and power is supplied and electric signals are transmitted via the

slip rings

60a and 60b. At this time, the elastic member 66 presses the fixed electrode 64 toward the

differential rotation portions

74a and 74b with an appropriate pressing force. As a result, the sliding insulating portion 78 is elasto-plastically deformed to receive most of the pressing force, and the rotating body electrode 62 and the fixed electrode 64 and the sliding

conductors

76a and 76b are in contact with each other by critical contact where almost no pressing force is applied. Conducts.

Next, when the rotating body 40 rotates, the rotating body electrode 62 rotates and the rolling element 706 of the bearing 70 revolves on its own, and the revolving motion of the rolling body 706 is transmitted to the differential

rotating portions

74a and 74b by the transmission member 72. do. As a result, the

differential rotation portions

74a and 74b rotate in the same direction as the rotating body 40 at a rotation speed of about ½ of the rotating body 40. As a result, the sliding

conductors

76a and 76b rotate and slide with respect to the fixed electrode 64 at a rotation speed of about ½ of the rotating body 40 while maintaining the conduction state with the fixed electrode 64. Further, the rotating body electrode 62 rotates and slides with respect to the sliding

conductors

76a and 76b at a rotation speed of about 1/2 of that of the rotating body 40 while maintaining the conduction state with the sliding

conductors

76a and 76b. As a result, the electrical connection between the rotating body 40 and the fixed body 12 is well maintained, and power supply and electric signal transmission via the

slip rings

60a and 60b are continuously performed.

As described above, in the

slip rings

60a and 60b according to the present invention, since the differential

rotating portions

74a and 74b are rotated by about 1/2 of the rotating body 40, the wear of the sliding portion can be reduced by that amount. .. Further, the

slip rings

60a and 60b according to the present invention contact and conduct the rotating body electrode 62 and the fixed electrode 64 and the sliding

conductors

76a and 76b by critical contact where almost no pressing force is applied. Therefore, the wear of the sliding portion can be further reduced.

Next, the

electric motors

80a and 80b according to the present invention will be described. In the

motors

80a and 80b according to the present invention, the

slip rings

60a and 60b of the present invention are applied to the

motors

80a and 80b described in [Patent Document 1]. However, the

slip rings

60a and 60b according to the present invention are not limited to the application to the

motors

80a and 80b described in [Patent Document 1], and are not limited to the application to the

motors

80a and 80b described in [Patent Document 1]. , And other well-known rotating bodies. Further, although the example in which the slip ring 60a of the first form is applied to the electric motor 80a of the first form and the slip ring 60b of the second form is applied to the electric motor 80b of the second form is used. The combination is not particularly limited, and the slip ring 60b of the second form is applied to the electric motor 80a of the first form, and the slip ring 60a of the first form is applied to the electric motor 80b of the second form. It doesn't matter.

First, a configuration common to the

motors

80a and 80b according to the present invention will be described. The

electric motors

80a and 80b according to the present invention shown in FIGS. 7 and 8 are located outside the output shaft 10 for transmitting the rotational force to the driven body M, the rotor 30 fixed to the output shaft 10, and the rotor 30. The stator 40, the fixed bearing portion 12 that rotatably supports the output shaft 10 and the stator 40, a plurality of coils 42 provided on the stator 40 to rotate the rotor 30 by flowing a drive current, and the stator 40. It has a stator rotation mechanism 46 that rotatably holds the stator 40 in the same direction as the rotor 30, a bearing 70 that rotatably supports the stator 40 with respect to the fixed bearing portion 12, and

slip rings

60a and 60b of the present invention. ing. The slip rings 60a and 60b of the present invention are provided between the stator 40 as a rotating body (40) and the fixed bearing portion 12 as a fixed body (12), and drive a current from the fixed bearing portion 12 side. It has a function of supplying to the coil 42 provided in the stator 40. In the

motors

80a and 80b according to the present invention, the bearing 70 corresponds to the bearing 70 of the

slip rings

60a and 60b. Further, when the

motors

80a and 80b according to the present invention are applied to a vehicle such as an electric vehicle, the driven body M is a wheel or a deceleration mechanism for rotating the wheel.

The rotor 30 (output shaft 10) is rotatably supported by the fixed bearing portion 12, and a reverse rotation preventing means 16 is provided between the rotor 30 (output shaft 10) and the fixed bearing portion 12. In addition to restricting the rotation of the 30 in the opposite direction, for example, when the driven body M is stopped, the rotor 30 and the fixed bearing portion 12 are fixed to prevent the rotor 30 from rotating.

Further, the stator rotation mechanism 46 that holds the stator 40 has a bearing portion 46a such as a well-known bearing that rotatably supports the rotor 30 with respect to the stator 40, and the stator 40 is in the direction opposite to the rotation direction of the rotor 30. It is mainly composed of a reverse rotation preventing means 46b that regulates rotation.

Further, as the reverse rotation preventing means 16 and 46b, a well-known member such as a one-way clutch or an electromagnetic clutch may be used, or a ratchet gear 50 fixed to the fixed bearing portion 12 and a ratchet fixed to the rotor 30 side or the stator 40 side. It has a claw portion 52 urged to the side of the gear 50, and the claw portion 52 slides on the ratchet gear 50 to rotate in the forward rotation, and allows rotation in this direction, and also allows the claw portion to rotate in the reverse direction. 52 meshes with the ratchet gear 50 to prevent rotation in this direction, and when the rotor 30 or the stator 40 exceeds a predetermined rotation speed, the claw portion 52 rotates outward due to centrifugal force to separate from the ratchet gear 50. You may use it. In this configuration, when the rotor 30 or the stator 40 is rotating at high speed, the claw portion 52 and the ratchet gear 50 are separated from each other and become non-contact, so that frictional resistance and vibration can be prevented from occurring.

Next, the configuration of the electric motor 80a according to the first aspect of the present invention will be described. The electric machine 80a of the first embodiment shown in FIG. 7 is an electric motor operated by a direct current, has a plurality of coils 42 functioning as armatures on the stator 40 side, and has a field magnet as a field portion on the rotor 30 side. It has a plurality of magnets 32. The coil 42 of the stator 40 is provided with a magnetic core in the winding core, and a plurality of coils 42, for example, 36, are arranged at regular intervals in the circumferential direction. Further, two rotor disks 34 are fixed to the rotor 30 of the motor 80a so as to sandwich the coil 42 on the stator 40 side, and a plurality of field magnets 32 are placed inside the rotor disk 34 to coil the stator 40 side. It is fixed at equal intervals so as to face the magnetic core of 42. The field magnet 32 is a permanent magnet for forming a field magnetic flux with respect to the coil 42 to rotate the rotor 30, so that the adjacent magnetic poles are reversed along the circumferential direction, that is, the N pole and the S pole. Are arranged so as to appear alternately. Further, as the field magnet 32, a metal magnet or a sintered magnet may be used, but it is particularly preferable to use a rare earth magnet such as a neodymium magnet having a large magnetic force. When the number of coils 42 is 36, six pairs of field magnets 32 are provided so as to sandwich the coils 42, for example.

Further, the position information acquisition means 18 for acquiring the relative position of the field magnet 32 with respect to the coil 42 and the rotation speed of the output shaft 10 (rotor 30) are input to the electric motor 80a, and the position information from the position information acquisition means 18 is input. Based on this, a control unit (not shown) that controls the flow direction of the drive current to the coil 42 is provided. The position information acquisition means 18 is not particularly limited, and any known position sensor, a well-known magnetic position detector such as a resolver type angle measuring device, a well-known optical position detector, or the like may be used. In addition to the one that directly acquires the relative position, the position information acquisition means 18 includes a coil position information acquisition means that acquires the absolute position of the coil 42 and a magnet position information acquisition means that acquires the absolute position of the field magnet 32. May be provided individually, and the control unit or the like may calculate the relative position of the coil 42 from the absolute position of the coil 42 and the absolute position of the field magnet 32. In FIG. 7, as the position information acquisition means 18, a slit plate 18a that rotates together with the rotor 30 and has an opening formed at a predetermined position, and a light emitting element 18b that is fixed to the stator 40 and installed across the opening of the slit plate 18a. An example of using an optical position detecting means having the light receiving element 18b'is shown.

Then, in this optical position information acquisition means 18, the relative position between the coil 42 and the field magnet 32 is based on the light receiving signal when the light of the light emitting element 18b reaches the light receiving element 18b'through the opening of the slit plate 18a. To get. Then, the control unit performs a rotation operation requested by a higher-level control device or the like based on the relative position of the rotor 30 (field magnet 32) with respect to the stator 40 (coil 42) and the rotation speed of the output shaft 10 (rotor 30). The current value and the flow direction of the drive current flowing down to each coil 42 are controlled so as to perform the above. Then, this drive current is supplied from the fixed bearing portion 12 side to each fixed electrode 64 of the slip ring 60a (60b), and is transmitted to the rotating body electrode 62 on the stator 40 side via the sliding conductor 76a (76b). Ru. Then, the rotor 30 flows down to the coil 42 connected to the rotating body electrode 62, and the rotor 30 rotates at the torque and the rotation speed instructed by the control unit.

Next, the configuration of the electric motor 80b according to the second aspect of the present invention will be described. The electric motor 80b of the second form is an electric motor operated by an alternating current. First, the rotor 30 of the electric motor 80b has, for example, a rotor core 36 in which an electromagnetic steel sheet is bonded in a cylindrical shape. A plurality of coils 42 having a magnetic core are installed inside the stator 40 facing the rotor core 36 so that the magnetic core faces the rotor core 36 side. Then, for example, in the case of the U-phase, V-phase, and W-phase three-phase alternating current motor 80b, the coils 42 corresponding to each of the U-phase, V-phase, and W-phase are arranged in order. Further, the slip ring 60b (60a) transmits alternating currents of U-phase, V-phase, and W-phase from the fixed bearing portion 12 side via the fixed electrode 64, the sliding conductor 76b (76a), and the rotating body electrode 62, and the stator 40. It is supplied to the coil 42 on the side. Then, the alternating currents of the U phase, the V phase, and the W phase supplied via the slip ring 60b (60a) flow down to the respective coils 42 in order, so that the magnetic field formed by the coils 42 rotates, and this rotation occurs. An eddy current flows down the rotor core 36 due to the magnetic field, and a Lorentz force acts to rotate the rotor 30.

Next, the characteristic operation of the

motors

80a and 80b according to the present invention will be described with reference to FIG. Here, FIG. 9A is a schematic NT diagram in which the horizontal axis is the rotation speed N of the output shaft 10 and the vertical axis is the torque T of the output shaft 10, and FIG. 9B is a rotor 30. In order to explain the change in the rotation speed of the stator 40, it is a figure which shows these change schematically by a straight line.

First, when the power is off, the rotors 30 and the stator 40 of the

motors

80a and 80b are both stopped (point 0 in FIG. 9B). Next, when the

motors

80a and 80b are started, the control unit applies a current in the reverse rotation direction to the coil 42 via the

slip rings

60a and 60b in a state where the reverse rotation prevention means 16 prevents the reverse rotation of the rotor 30. do. As a result, a force acts on the rotor 30 in the reverse rotation direction, but since the reverse rotation of the rotor 30 is prevented as described above, the force generated in the rotor 30 acts as a reaction force and acts on the stator 40. As a result, the stator 40 rotates in the forward direction. Then, when the stator 40 reaches a predetermined rotation speed (point A in the broken line in FIG. 9B), when an output request is made to the output shaft 10 such as stepping on the accelerator, the control unit performs the rotor 30. A drive current that causes the rotor 30 to rotate in the forward direction is caused to flow down to the coil 42 via the

slip rings

60a and 60b. In the AC motor 80b, in addition to the AC drive current having a predetermined frequency, a DC current that does not interfere with the operation of the motor 80b is superimposed on the drive current via the

slip rings

60a and 60b and flows down. As a result, the rotor 30 and the stator 40 are magnetically coupled, and the rotor 30 starts rotating in the same direction (forward direction) due to the rotational force of the stator 40. In addition to this, a drive current that rotates the rotor 30 in the forward direction flows down to the coil 42, so that the drive current also causes the rotor 30 to rotate in the forward direction. _{As a result, as shown at point A in FIG. 9A, the rotor 30 rotates at a torque T 0} that is a combination of the torque Tw generated by the supply power Kw of the drive current and the torque generated by the rotational force Ki of the stator 40. Operate. Incidentally, shows a configuration for limiting a torque T ₀ the torque of the rotor 30 in FIG. 9 (a). In this case, when the rotation of the rotor 30 starts, the rotational force Ki of the stator 40 mainly rotates the rotor 30, and the surplus shown by the broken line in FIG. 9A becomes a current component and is supplemented with the drive current. Therefore, the power supply from the power source can be reduced accordingly.

Then, when this torque T ₀ is applied, the rotor 30 starts to rotate. Here, _{if the virtual torque due to the rotational force Ki when not limited by the torque T 0} is shown as the torque T'in FIG. 9 (a), this torque T'decreases with the rotation of the rotor 30, and the torque T'is reduced. Therefore, the amount of compensation for the drive current from the stator 40 side is also reduced. Further, since the rotational force Ki of the stator 40 is used for the rotation of the rotor 30, the rotational speed Nm of the stator 40 shown by the broken line in FIG. 9B decreases, and the rotor shown by the solid line in FIG. 9B. The rotation speed Nc of 30 increases. Then, at a certain point B, the rotation speed Nm of the stator 40 and the rotation speed Nc of the rotor 30 become equal to each other, and thereafter, the rotation speed Nc of the rotor 30 becomes faster than the rotation speed Nm of the stator 40. Incidentally, shows an example in which the point B to the FIG. 9 (a) in Nm = Nc becomes torque _{T 0.}

Here, in the conventional motor in which the stator does not rotate, a counter electromotive force Ke is immediately generated as the rotor rotates, and this counter electromotive force Ke reduces the output NT of the rotor. This counter electromotive force Ke increases as the angular velocity ω with respect to the rotor stator increases. Therefore, in the conventional motor in which the stator is fixed, a large supply power Kw that compensates for the loss due to the counter electromotive force Ke is required in order to maintain a predetermined output N / T.

However, in the

motors

80a and 80b according to the present invention, in the region where the rotation speed Nm of the stator 40 is faster than the rotation speed Nc of the rotor 30 Nm> Nc (the region between points A and B in FIG. 9B). The angular velocity ω of the rotor 30 with respect to the stator 40 becomes negative, and the counter electromotive force Ke causes the current that supplements the drive current to flow down. As a result, the power supplied from the power source can be reduced as described above.

In the

electric motors

80a and 80b according to the present invention, the counter electromotive force Ke does not occur until Nm = Nc (point B in FIG. 9B) where the rotation speed Nm of the stator 40 becomes equal to the rotation speed Nc of the rotor 30. , All the supply power Kw can be used for the outputs N and T of the rotor 30. Then, when the rotation speed Nc of the rotor 30 becomes faster than the rotation speed Nm of the stator 40 Nc> Nm, a counter electromotive force Ke is generated, and a loss with respect to the outputs N and T occurs for the first time. That is, in the conventional motor in which the stator does not rotate, a loss occurs due to the counter electromotive force Ke immediately after the start of rotation of the rotor, whereas in the

motors

80a and 80b according to the present invention, the rotation speed Nc of the rotor 30 is the rotation speed Nm of the stator 40. No loss due to the back electromotive force Ke occurs until it exceeds. Therefore, the outputs N and T can be maintained without increasing the supply power Kw in the region where high torque at the initial stage of rotation of the rotor 30 is required.

Then, when the rotation speed Nc of the rotor 30 further increases, the rotation speed Nm of the stator 40 decreases, and the stator 40 finally stops (point C in FIG. 9B). In the region of Nc> Nm> 0 (the region between points B and C in FIG. 9B) until the stator 40 stops, the stator 40 is still in a rotating state although a loss occurs due to the back electromotive force Ke. Therefore, the counter electromotive force Ke becomes a small value by the amount of the rotation speed Nm of the stator 40, and the counter electromotive force Ke generated is small and the loss is small as compared with the conventional electric motor in which the stator does not rotate. Then, the

motors

80a and 80b show the same behavior as the conventional motors after the point C in FIG. 9B when the stator 40 is stopped.

Thus, the electric motor 80a according to the present invention, 80b is for using a rotational force Ki of the stator 40 in the rotation of the rotor 30, be rotated operate at high torque T ₀ than the torque Tw generated by only conventional supply power Kw can. Here, when the torque T ₀ is twice the torque Tw, at the point Nm = Nc where the rotation speed Nm of the stator 40 is equal to the rotation speed Nc of the rotor 30, the stator does not rotate and rotates only with the supply power Kw. It is possible to obtain an output NT that is four times higher in calculation than a conventional motor in which a loss due to the countercurrent force Ke is generated.

Next, when the rotor 30 of the

motors

80a and 80b is rotated and the stator 40 is stopped, a request is made to decelerate the rotation of the output shaft 10 (rotor 30), for example, by stepping on a brake. A drive current that slows down the rotation of 30 flows down to the coil 42 via the

slip rings

60a and 60b. As a result, the rotational speed of the rotor 30 decreases, and at the same time, a reaction force is generated between the rotor 30 and the stator 40, and this reaction force causes the stator 40 to rotate in the forward direction. As a result, the rotational force of the rotor 30 is converted into the rotation of the stator 40. Then, when an output request for forward rotation to the output shaft 10 such as stepping on the accelerator is made again, the rotational force Ki of the stator 40 acts to rotate the rotor 30 in the same manner as in the previous operation. As described above, the

electric motors

80a and 80b according to the present invention accumulate the rotational force of the rotor 30 as the rotational force of the stator 40 with the kinetic energy at the time of braking or the like, and the rotational force of the stator 40 at the time of restarting or the like. Is used for the rotation of the rotor 30 with the kinetic energy. Therefore, the energy loss is small, and the kinetic energy of the rotor 30 and the stator 40 can be fully utilized.

As described above, the

slip rings

60a and 60b according to the present invention and the

electric motors

80a and 80b provided with the

slip rings

60a and 60b are the differential rotating portions 74a, which are sliding portions by utilizing the revolving motion of the bearing 70. The 74b is rotated at about 1/2 the rotation speed of the rotating body 40. As a result, the substantial rotation speed of the sliding portion is reduced, and the wear of the sliding portion can be reduced. Further, in the

slip rings

60a, 60b and the

electric motors

80a, 80b according to the present invention, the one-pole sliding electrode is composed of a plurality of sliding

conductors

76a, 76b, and is slid in the gap between the sliding

conductors

76a, 76b. The sliding insulation portion 78, which is softer than the

dynamic conductors

76a and 76b, is positioned. As a result, the pressing force on the sliding

conductors

76a and 76b is received by the sliding insulating portion 78 side, the pressing force applied to the sliding

conductors

76a and 76b is reduced, and the pressing force is extremely small. The

conductors

76a and 76b can be contact-conducted with the rotating body electrode 62 and the fixed electrode 64. As a result, the wear of the sliding

conductors

76a and 76b, the rotating body electrode 62, and the fixed electrode 64 can be further reduced. Further, by forming a noble metal thin film that is difficult to ionize on the contact surface between the rotating body electrode 62 and the sliding

conductors

76a and 76b of the fixed electrode 64, electrolytic corrosion of the rotating body electrode 62 and the fixed electrode 64 is prevented, and the electrode Wear can be further reduced.

The configurations of the

slip rings

60a and 60b shown in this example are examples, and the shape, dimensions, mechanism, design, number, etc. of each part may be changed and implemented without departing from the gist of the present invention. It is possible.

10 Output shaft 12 Fixed body (fixed bearing part)
30 Rotor 40 Rotating body (stator)
42

Coil

60a, 60b Slip ring 62 Rotating body electrode 64 Fixed electrode 66 Elastic member 70 Bearing 72

Transmission member

74a, 74b

Differential rotating part

76a, 76b Sliding conductor 78 Sliding

insulation part

80a, 80b Motor 706 Rolling element M Drive

Claims

A rotating body electrode provided on the rotating body side and a fixed electrode provided on the fixed body side,
A bearing that rotatably holds the rotating body and
A rolling element that constitutes the bearing and revolves with the rotation of the rotating body, and
A transmission member that transmits the revolution movement of the rolling element, and
A differential rotating portion that is connected to the transmission member and rotates by the revolution motion of the rolling element,
A sliding conductor provided in the differential rotating portion, in which the rotating body electrode abuts on one surface and the fixed electrode abuts on the other surface.
A slip ring having an elastic member that presses the rotating body electrode or the fixed electrode on the side of the differential rotating portion with a predetermined force.
A sliding insulating portion is located between the sliding conductors, and the sliding insulating portion is deformed in the elastic region of elasto-plastic deformation to reduce the pressing force on the sliding conductor, and the sliding conductor and the sliding conductor The slip ring according to claim 1, wherein the rotating body electrode and the fixed electrode are contact-conducted in a critical contact state where the pressing force is extremely small.
The differential rotating portion has a disk shape, and the sliding conductor has an arcuate end face and is arranged in a circular shape concentric with the differential rotating portion. Further, both end faces of the sliding conductor are the differential rotating portion. Exposed flush to both planes,
The slip ring according to claim 2, wherein the rotating body electrode and the fixed electrode are concentric with the differential rotating portion and have a ring shape having substantially the same radius as the sliding conductor.
The slip ring according to claim 3, wherein the sliding conductor is made of a carbon plate having conductivity, and has a noble metal thin film on the contact surface between the rotating body electrode and the sliding conductor of the fixed electrode.
The differential rotation portion has a cylindrical shape, and the sliding conductor has an arch shape having the same curvature as the differential rotation portion and is arranged so as to make one round in the circumferential direction. The inner peripheral surface and the outer peripheral surface of the sliding conductor are exposed flush with the inner peripheral surface and the outer peripheral surface of the differential rotating portion.
The outer peripheral surface of the rotating body electrode has an arch shape having substantially the same curvature as the inner peripheral surface of the sliding conductor, and the inner peripheral surface of the fixed electrode has substantially the same curvature as the outer peripheral surface of the sliding conductor. It has an arch shape, and the outer peripheral surface of the rotating body electrode is in contact with the inner peripheral surface of the sliding conductor, and the inner peripheral surface of the fixed electrode is in contact with the outer peripheral surface of the sliding conductor to conduct conduction. The slip ring according to claim 2.
The slip ring according to claim 5, wherein the sliding conductor is made of a carbon plate having conductivity, and has a noble metal thin film on the outer peripheral surface of the rotating body electrode and the inner peripheral surface of the fixed electrode.
An output shaft that transmits rotational force to the driven body,
The rotor fixed to the output shaft and
The stator located on the outside of the rotor and
A fixed bearing portion that rotatably supports the output shaft and the stator, and
A plurality of coils provided in the stator and rotating the rotor by flowing a drive current, and
It has a stator rotation mechanism that rotatably holds the stator in the same direction as the rotor.
When the rotation of the rotor is decelerated, the rotational force of the rotor is converted into the rotation of the stator.
In an electric motor that rotates the rotor by applying the rotational force of the stator to the rotational force of the drive current by passing the drive current in a state where the stator is rotated.
The invention according to any one of claims 1 to 6, which is provided between the stator as a rotating body and the fixed bearing portion as a fixed body, and supplies a drive current from the fixed bearing portion side to the coil. An electric motor characterized by further having a slip ring.