WO2022158206A1

WO2022158206A1 - Electromagnetic clutch

Info

Publication number: WO2022158206A1
Application number: PCT/JP2021/046832
Authority: WO
Inventors: 和真橘; 清黒畑; 敏弘林; 俊宏小西; 茂圭櫻場; 広樹永橋
Original assignee: 株式会社デンソー
Priority date: 2021-01-20
Filing date: 2021-12-17
Publication date: 2022-07-28
Also published as: JP2022111696A; JP7415962B2

Abstract

An armature (10) has an outer ring portion (11), an inner ring portion (12), and a long hole (13) having an arc shape. An outer plate (20) has: an opposing wall (21) fixed to the armature (10) and facing the armature (10); and an upright wall (22) extending from the opposing wall (21) in the rotation axis direction. An inner hub (30) is provided between the armature (10) and the outer plate (20), and transmits a torque to a driven body (70). An elastic member (40) has: a buffer portion (42) provided between the upright wall (22) and an inner-side upright wall (34); and a vibration damping portion (43) provided between the opposing wall (21) and the armature (10). At least one of the opposing wall (21) and the armature (10) is provided with a recess-shaped portion (16, 25) that makes a distance (D2) between the armature (10) and the opposing wall (21) longer than a distance (D1) between the armature (10) and a part (21a) where the opposing wall (21) and the upright wall (22) are connected to each other.

Description

electromagnetic clutch

Cross-references to related applications

This application is based on Japanese Patent Application No. 2021-7298 filed on January 20, 2021, the contents of which are incorporated herein by reference.

This disclosure relates to an electromagnetic clutch.

Conventionally, an electromagnetic clutch is known that switches between a state of transmitting torque from a driver to a driven body and a state of not transmitting torque.
The electromagnetic clutch described in Patent Literature 1 is a hub that transmits torque from a rotor, which is a driving body that rotates under the power of an engine, to an air-conditioning compressor, which is a driven body. This electromagnetic clutch includes an armature provided facing a rotor, an outer plate fixed to the armature, an inner hub and an elastic member provided between the armature and the outer plate.

The armature provided in this electromagnetic clutch is formed in an annular shape, and includes an outer ring portion provided on the outer peripheral side, an inner ring portion provided on the rotating shaft side with respect to the outer ring portion, and an armature extending in the circumferential direction between the outer ring portion and the inner ring portion. It has an elongated hole extending in an arc shape. On the other hand, the rotor is also formed in an annular shape and has a rotor inner diameter portion, a rotor central portion, and a rotor outer diameter portion. With this configuration, when the electromagnetic coil provided inside the rotor is energized, the rotor and armature are connected in the order of "rotor inner diameter - armature inner ring - rotor center - armature outer ring - rotor outer diameter". Magnetic flux flows so as to reciprocate multiple times. This electromagnetic clutch thereby increases the magnetic attraction force between the rotor and the armature.

Also, this electromagnetic clutch has a structure in which an elastic member is sandwiched between the armature and the outer plate. An elastic member is arranged so as to straddle the inner ring portion and the outer ring portion of the armature, and the elastic member is pressed against the armature by the outer plate. As a result, when the electromagnetic coil is energized, the electromagnetic clutch suppresses vibrations of the inner ring portion and the outer ring portion of the armature by means of the elastic member, thereby reducing operating noise. The operating noise includes contact noise generated when the armature contacts the rotor when the electromagnetic coil is energized, and resonance noise generated by vibration generated by slippage between the armature and the rotor.
Furthermore, this electromagnetic clutch is configured such that an elastic member is sandwiched between a surface of the outer plate facing the rotational direction and a surface of the inner hub facing the rotational direction. As a result, this electromagnetic clutch has increased durability against torque fluctuations.

JP 2019-27490 A

However, in the electromagnetic clutch disclosed in Patent Document 1, the outer plate and the elastic member are arranged across the inner ring portion and the outer ring portion of the armature in order to reduce operating noise. There is concern that magnetic flux leakage may occur between Specifically, when the electromagnetic coil is energized, the amount of magnetic flux flowing through “armature inner ring – outer plate – armature outer ring” increases, and the magnetic flux flowing through “armature inner ring – rotor center – armature outer ring” increases. Decrease. As a result, if the magnetic attraction force between the rotor and the armature is weakened, there is a risk that torque transmission from the rotor to the driven body will be deteriorated.

In order to prevent magnetic flux leakage between the armature and the outer plate, the thickness of the elastic member arranged between the outer plate and the armature (that is, the distance in the direction of the rotational axis of the electromagnetic clutch in the elastic member) is generally adjusted to It can be considered to be thicker. However, in this case, the height of the surface of the outer plate facing the rotational direction (that is, the distance in the rotational axis direction of the electromagnetic clutch between the surface of the outer plate facing the rotational direction) is reduced. Therefore, the elastic member disposed between the surface of the outer plate that faces the rotational direction and the surface of the inner hub that faces the rotational direction also becomes smaller, resulting in reduced durability against torque fluctuations.

An object of the present disclosure is to provide an electromagnetic clutch capable of reducing operating noise, improving durability, and further improving torque transmissibility by improving magnetic performance.

According to one aspect of the present disclosure, an electromagnetic clutch that switches between a state in which torque is transmitted from a rotor that has an electromagnetic coil and rotates about a predetermined rotation axis to a driven body and a state in which torque is blocked includes an armature, an outer plate, It has an inner hub and an elastic member. The armature is provided to face the rotor on one side in the direction of the rotation axis of the rotor, and includes an outer ring portion provided on the outer peripheral side, an inner ring portion provided on the side of the rotation shaft with respect to the outer ring portion, and an outer ring portion and an inner ring portion. It has an elongated hole that extends in an arc shape in the circumferential direction between and can contact the rotor by the magnetic attraction force generated by the electromagnetic coil. The outer plate is fixed to the armature, has a facing wall facing a surface of the armature opposite to the rotor, an upright wall extending from the facing wall in the rotation axis direction of the rotor, and one of the upright walls on the side opposite to the facing wall. It has a flange extending from the portion perpendicular to the axis of rotation of the rotor and rotates with the armature. The inner hub is provided between the armature and the outer plate, has an inner standing wall facing the standing wall and an inner flange facing the flange, and transmits torque to the driven body. The elastic member includes an urging portion provided between the flange and the inner flange, a buffer portion provided between a surface of the vertical wall facing the rotational direction and a surface of the internal vertical wall facing the rotational direction, and an opposing wall. It has a damping part provided between it and the armature.
At least one of the opposing wall and the armature is provided with a concave portion that makes the distance between the armature and the opposing wall greater than the distance between the armature and the portion where the opposing wall and the standing wall are connected.

According to this, by pressing the damping portion of the elastic member against the inner ring portion and the outer ring portion of the armature by the opposing wall of the outer plate, the vibration of the inner ring portion and the outer ring portion of the armature is suppressed when the electromagnetic coil is energized. Sound can be reduced.
In addition, by shortening the distance between the portion of the outer plate where the opposing wall and the vertical wall are connected to the armature, the height of the vertical wall and the buffer portion (i.e., Since it is possible to increase the distance in the rotation axis direction, it is possible to increase durability against torque fluctuations.
Further, by increasing the distance between the armature and the opposing wall by means of the recessed portion provided in at least one of the opposing wall and the armature, the magnetic path formed by the "armature inner ring portion-opposing wall-armature outer ring portion" is formed when the electromagnetic coil is energized. It becomes possible to increase the magnetic resistance. Therefore, when the electromagnetic coil is energized, magnetic flux leakage between the armature and the outer plate is reduced, and the amount of magnetic flux flowing through "armature inner ring portion-rotor center portion-armature outer ring portion" is increased. Therefore, the magnetic attractive force between the rotor and the armature is increased. As a result, this electromagnetic clutch has improved magnetic performance, and can enhance torque transmission from the rotor to the driven body.

According to another aspect, an electromagnetic clutch that switches between a state in which torque is transmitted from a rotor that has an electromagnetic coil and rotates about a predetermined rotation axis to a driven member and a state in which torque is not transmitted, includes an armature, an outer plate, and an inner hub. and an elastic member. The armature is provided to face the rotor on one side in the direction of the rotation axis of the rotor, and includes an outer ring portion provided on the outer peripheral side, an inner ring portion provided on the side of the rotation shaft with respect to the outer ring portion, and an outer ring portion and an inner ring portion. It has an elongated hole that extends in an arc shape in the circumferential direction between and can contact the rotor by the magnetic attraction force generated by the electromagnetic coil. The outer plate is fixed to the armature, has a facing wall facing a surface of the armature opposite to the rotor, an upright wall extending from the facing wall in the rotation axis direction of the rotor, and one of the upright walls on the side opposite to the facing wall. It has a flange extending from the portion perpendicular to the axis of rotation of the rotor and rotates with the armature. The inner hub is provided between the armature and the outer plate, has an inner standing wall facing the standing wall and an inner flange facing the flange, and transmits torque to the driven body. The elastic member includes an urging portion provided between the flange and the inner flange, a buffer portion provided between a surface of the vertical wall facing the rotational direction and a surface of the internal vertical wall facing the rotational direction, and an opposing wall. It has a damping part provided between it and the armature.
The opposing wall is divided into a radially inner portion and a radially outer portion, and the magnetic resistance between the radially inner portion of the opposing wall and the radially outer portion of the opposing wall is determined. A reluctance hole for increasing the .DELTA.

According to this, by pressing the damping portion of the elastic member against the inner ring portion and the outer ring portion of the armature by the opposing wall of the outer plate, the vibration of the inner ring portion and the outer ring portion of the armature is suppressed when the electromagnetic coil is energized. Sound can be reduced.
In addition, by shortening the distance between the portion of the outer plate where the opposing wall and the vertical wall are connected to the armature, the height of the vertical wall and the buffer portion (i.e., Since it is possible to increase the distance in the rotation axis direction, it is possible to increase durability against torque fluctuations.
Furthermore, by providing a magnetic resistance hole in the opposing wall of the outer plate, it is possible to increase the magnetic resistance of the magnetic path by "armature inner ring portion-opposing wall-armature outer ring portion" when the electromagnetic coil is energized. Therefore, when the electromagnetic coil is energized, magnetic flux leakage between the armature and the outer plate is reduced, and the amount of magnetic flux flowing through "armature inner ring portion-rotor center portion-armature outer ring portion" is increased. Therefore, the magnetic attractive force between the rotor and the armature is increased. As a result, this electromagnetic clutch has improved magnetic performance, and can enhance torque transmission from the rotor to the driven body.

It should be noted that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and the specific component etc. described in the embodiment described later.

1 is an overall configuration diagram of a refrigeration cycle to which an electromagnetic clutch according to a first embodiment is applied; FIG. 1 is an exploded perspective view of an electromagnetic clutch, a rotor, and a stator according to the first embodiment; FIG. 1 is a plan view of an electromagnetic clutch according to a first embodiment; FIG. FIG. 4 is a cross-sectional view of an electromagnetic clutch, a rotor, etc. taken along line IV-IV of FIG. 3; FIG. 3 is a plan view of an armature included in the electromagnetic clutch according to the first embodiment; 3 is a plan view of an outer plate included in the electromagnetic clutch according to the first embodiment; FIG. FIG. 3 is a plan view showing a state in which only an armature and an outer plate included in the electromagnetic clutch according to the first embodiment are assembled; FIG. 4 is a cross-sectional view of the electromagnetic clutch, rotor, etc. taken along line VIII-VIII in FIG. 3, and is an explanatory diagram for explaining the flow of magnetic flux when the electromagnetic coil is energized; 3 is a plan view of an inner hub included in the electromagnetic clutch according to the first embodiment; FIG. 4 is a plan view of an elastic member included in the electromagnetic clutch according to the first embodiment; FIG. It is a top view which shows some electromagnetic clutches which concern on 2nd Embodiment. FIG. 11 is a cross-sectional view showing part of an electromagnetic clutch according to a third embodiment; FIG. 11 is a cross-sectional view showing part of an electromagnetic clutch according to a fourth embodiment; FIG. 11 is a plan view showing part of an electromagnetic clutch according to a fourth embodiment; FIG. 11 is a cross-sectional view showing part of an electromagnetic clutch according to a fifth embodiment; FIG. 11 is a plan view showing part of an electromagnetic clutch according to a fifth embodiment; FIG. 5 is an explanatory diagram for explaining the flow of magnetic flux when an electromagnetic coil is energized in an electromagnetic clutch of a comparative example;

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, in each of the following embodiments, the same or equivalent portions are denoted by the same reference numerals, and description thereof will be omitted.

(First embodiment)
A first embodiment will be described. As shown in FIG. 1, the electromagnetic clutch 1 of this embodiment is a torque transmission device for intermittently transmitting torque from a rotor 50 as a driving body to a compressor 70 as a driven body. The electromagnetic clutch 1 is also called a hub.

First, a refrigeration cycle 71 using a compressor 70 as a driven body will be described. The refrigerating cycle 71 is used in a vehicle air conditioner (not shown) that air-conditions the interior of the vehicle or the interior of the refrigerator. As shown in FIG. 1 , a refrigerating cycle 71 is configured as a closed circuit in which a compressor 70 , a condenser 72 , an expansion valve 73 , and an evaporator 74 are annularly connected by a refrigerant pipe 75 . The compressor 70 sucks refrigerant from a refrigerant pipe 75 on the evaporator 74 side, compresses it, and discharges it. The condenser 72 is a heat exchanger that condenses the refrigerant by exchanging heat between the refrigerant discharged from the compressor 70 and the outside air. The expansion valve 73 decompresses and expands the refrigerant flowing out of the condenser 72 . The evaporator 74 is a heat exchanger that evaporates the refrigerant decompressed and expanded by the expansion valve 73 by exchanging heat with the air that is blown into the vehicle interior or the refrigerator.

As the compressor 70, for example, a fixed capacity compressor such as a scroll type or vane type, or a variable capacity type compressor such as a swash plate type is adopted. A rotor 50 as a driving body is provided on one end side of the compressor 70 . The rotor 50 is rotatable relative to the housing of the compressor 70 and the like.

The vehicle is provided with an engine 80 for driving the vehicle as a power generation source. A pulley 82 provided on a drive shaft 81 of the engine 80 and the rotor 50 are connected by a power transmission belt 83 . Torque output from the engine 80 is transmitted from the pulley 82 to the rotor 50 via the belt 83 . Therefore, the rotor 50 rotates as the engine 80 is driven. An electromagnetic clutch 1 is provided on the side opposite to the compressor 70 with respect to the rotor 50 . Torque transmitted from the engine 80 to the rotor 50 is configured to be transmitted to the shaft of the compressor 70 via the electromagnetic clutch 1 .

Next, the rotor 50 will be described with reference to FIGS. 2 and 4. FIG. The rotor 50 is mainly made of a ferromagnetic material such as iron, and is rotatable around a predetermined rotation axis Ax. In the following description, the side closer to the rotation axis Ax may be referred to as the radial inner side, and the side farther from the rotation axis Ax may be referred to as the radial outer side. The rotor 50 includes an outer tubular portion 51 provided on the outer peripheral side, an inner tubular portion 52 provided radially inwardly of the outer tubular portion 51, and an annular portion connecting the outer tubular portion 51 and the inner tubular portion 52. 53 integrally.

The outer tubular portion 51 is formed in a cylindrical shape. A V-groove portion 54 formed of a plurality of grooves having a V-shaped cross section parallel to the rotation axis Ax is formed on the outer circumference of the outer cylindrical portion 51 . A belt 83 for transmitting the torque output from the engine 80 is stretched over the V groove portion 54 .

The inner cylindrical portion 52 is formed in a cylindrical shape and is provided closer to the rotation axis Ax than the outer cylindrical portion 51 is. An outer ring 91 of a ball bearing 90 is fixed to the inner peripheral side of the inner tubular portion 52 . On the other hand, the inner ring 92 of the ball bearing 90 is fixed to a cylindrical portion 77 projecting cylindrically from the housing of the compressor 70 . Thereby, the rotor 50 is provided rotatably relative to the housing of the compressor 70 .

The annular portion 53 is formed in an annular shape and connects the outer tubular portion 51 and the inner tubular portion 52 . The annular portion 53 is provided with a plurality of slits 55 extending in an arc shape in the circumferential direction. As shown in FIG. 4 , the plurality of slits 55 has an outer slit 551 and an inner slit 552 provided radially outside the outer slit 551 . In the following description, a portion of the rotor 50 radially outside the outer slit 551 may be referred to as a "rotor outer diameter portion 501". Also, a portion between the outer slit 551 and the inner slit 552 may be called a "rotor central portion 502". Also, a portion radially inward of the inner slit 552 may be referred to as a "rotor inner diameter portion 503".

The end surface of the annular portion 53 opposite to the compressor 70 serves as a friction surface that contacts the armature 10 of the electromagnetic clutch 1 . In the following description, the friction surface is referred to as the end surface 59 of the rotor 50. FIG. A friction member 56 for increasing the coefficient of friction is arranged at a portion of the end face 59 of the rotor 50 where the outer slit 551 is provided. As the friction member 56, for example, a non-magnetic material such as alumina hardened with resin or a sintered body of metal powder such as aluminum is used.

A stator 57 and an electromagnetic coil 58 are provided inside the rotor 50 . The stator 57 is made of a ferromagnetic material such as iron. The electromagnetic coil 58 is fixed inside the stator 57 while being molded with an insulating resin material. Therefore, the rotor 50 has an electromagnetic coil 58 inside. When the electromagnetic coil 58 is energized, magnetic flux flows through a magnetic circuit formed by the stator 57, the rotor 50, and the armature 10 of the electromagnetic clutch 1, which will be described later. As a result, a magnetic attractive force is generated that draws the armature 10 toward the rotor 50 side.

Next, the electromagnetic clutch 1 will be explained.

As shown in FIGS. 3 and 4, the electromagnetic clutch 1 includes an armature 10, an outer plate 20, an inner hub 30, elastic members 40, and the like.

The armature 10 is mainly made of a ferromagnetic material such as iron and has an annular shape, and is provided to face the end face 59 of the rotor 50 . A predetermined gap (for example, about 0.5 mm) is formed between the end surface 59 of the rotor 50 and the armature 10 when the electromagnetic coil 58 of the rotor 50 is not energized. In FIG. 4, for the sake of explanation, the gap between the end surface 59 of the rotor 50 and the armature 10 is shown relatively large.

On the other hand, when the electromagnetic coil 58 is energized, the armature 10 is drawn toward the rotor 50 by the magnetic attraction force generated by the electromagnetic coil 58 and comes into contact with the end face 59 of the rotor 50 . The armature 10 is joined to the end surface 59 of the rotor 50 by frictional force. In that state, the electromagnetic clutch 1 rotates together with the rotor 50 .

As shown in FIG. 5, the armature 10 is formed in an annular shape, and includes an outer ring portion 11 provided on the outer peripheral side, an inner ring portion 12 provided on the rotation axis Ax side of the outer ring portion 11, and an outer ring portion. Between 11 and inner ring portion 12, there are a plurality of elongated holes 13 extending in an arc shape in the circumferential direction. The plurality of elongated holes 13 serve as magnetic resistance portions that increase the magnetic resistance between the inner ring portion 12 and the outer ring portion 11 . In addition, the inner ring portion 12 and the outer ring portion 11 are mechanically connected by a connecting portion 14 provided between the plurality of long holes 13 . Also, the armature 10 is provided with a plurality of rivets 15 for fixing to the outer plate 20 . The rivet 15 is provided near the outer periphery of the armature 10 . Also, the rivet 15 and the connection portion 14 are provided at positions overlapping each other in the radial direction. However, the positions of the rivet 15 and the connecting portion 14 are not limited to the position where they overlap in the radial direction as shown in FIG. 5, and can be set arbitrarily. Also, the armature 10 and the rivet 15 may be configured as separate members.

As shown in FIGS. 3, 4 and 6, the outer plate 20 is provided on the side of the armature 10 opposite to the rotor 50. As shown in FIGS. The outer plate 20 is formed by pressing a ferromagnetic material such as an iron plate. By making the outer plate 20 and the armature 10 of the same kind of material, they have the same coefficient of linear expansion, and deformation of the outer plate 20 and the armature 10 can be prevented.

The outer plate 20 integrally has a facing wall 21, a vertical wall 22 and a flange 23. The facing wall 21 is a portion of the armature 10 that faces the surface of the armature 10 opposite to the rotor 50 . The standing wall 22 is a portion extending from the opposing wall 21 in the rotation axis direction of the rotor 50 . The flange 23 is a portion extending perpendicularly to the rotation axis Ax of the rotor 50 from a portion of the standing wall 22 opposite to the opposing wall 21 .

The facing wall 21 of the outer plate 20 is provided with insertion holes 24 into which the rivets 15 are inserted. The insertion hole 24 is provided at a position near the outer periphery of the outer plate 20 . A rivet 15 provided on the armature 10 is inserted into the insertion hole 24 . By crimping the tip of the rivet 15, the outer plate 20 and the armature 10 are fixed. Therefore, the outer plate 20 rotates together with the armature 10 .

A portion of the facing wall 21 is provided with an outer plate recessed portion 25 as a recessed portion. The outer plate recessed portion 25 is formed in a substantially fan shape when viewed from the rotation axis direction, and is provided at four locations in the circumferential direction of the outer plate 20 . The outer plate recessed portion 25 is provided between the standing wall 22 and the rivet 15 .

The outer plate concave portion 25 is farther from the armature 10 than the portion 21a of the opposing wall 21 that is connected to the standing wall 22 and the portion 21b of the opposing wall 21 that is provided with the insertion hole 24 into which the rivet 15 is inserted. Concave like this. Note that the outer plate concave portion 25 has a concave shape when viewed from the armature 10 side, and has a convex shape when viewed from the side opposite to the armature 10 . The outer plate concave portion 25 has a function of increasing the magnetic resistance between the armature 10 and the opposing wall 21 by increasing the distance between the armature 10 and the opposing wall 21 . Further, the outer plate concave portion 25 also has a function of increasing the rigidity of the opposing wall 21 .

FIG. 7 shows a state in which only the outer plate 20 and the armature 10 are assembled (that is, a state in which the inner hub 30 and the elastic member 40 are removed from the electromagnetic clutch 1). As shown in FIG. 7 , the facing wall 21 of the outer plate 20 is arranged across the inner ring portion 12 and the outer ring portion 11 of the armature 10 . An outer plate concave portion 25 provided in the facing wall 21 is provided across the inner ring portion 12 and the outer ring portion 11 of the armature 10 at a portion facing the long hole 13 of the armature 10 .

FIG. 8 is a cross-sectional view of the electromagnetic clutch 1, rotor 50, etc. taken along line VIII-VIII in FIG. As shown in FIG. 8, the distance between the armature 10 and the portion 21a where the opposing wall 21 and the standing wall 22 are connected is defined as D1. Also, the distance between the outer plate concave portion 25 provided in the opposing wall 21 and the armature 10 is defined as D2. At this time, the distance D2 between the outer plate concave portion 25 and the armature 10 is greater than the distance D1 between the armature 10 and the portion 21a where the opposing wall 21 and the standing wall 22 are connected. Therefore, the outer plate concave portion 25 functions as a magnetic resistance portion that increases magnetic resistance between the armature 10 and the opposing wall 21 .

FIG. 8 shows a state in which the electromagnetic coil 58 of the rotor 50 is energized (hereinafter referred to as "when the electromagnetic coil 58 is energized"). In FIG. 8, the magnetic flux flowing through the magnetic circuit formed by the stator 57, the rotor 50, and the armature 10 when the electromagnetic coil 58 is energized is indicated by a solid line M1. Further, in FIG. 8, the magnetic flux leaking from the armature 10 to the opposing wall 21 of the outer plate 20 at that time is indicated by a dashed line M2.

In this embodiment, the provision of the outer plate recess 25 in the opposing wall 21 increases the distance D2 between the outer plate recess 25 of the opposing wall 21 and the armature 10, increasing the magnetic resistance therebetween. In general, magnetic flux flows in the direction of smaller reluctance. Therefore, as indicated by the dashed line M2, the amount of magnetic flux flowing through “the inner ring portion 12 of the armature 10—the opposing wall 21 of the outer plate 20—the outer ring portion 11 of the armature 10” is negligibly small. 20 is reduced. Therefore, as indicated by the solid line M1, a magnetic circuit consisting of "stator 57--rotor inner diameter portion 503--inner ring portion 12 of armature 10--rotor central portion 502--armature 10 outer ring portion 11--rotor outer diameter portion 501--stator 57" is formed. The amount of magnetic flux flowing increases. Therefore, the magnetic attraction force between the rotor 50 and the armature 10 increases. As a result, the electromagnetic clutch 1 can improve the magnetic performance and improve the torque transmissibility from the rotor 50 to the compressor 70 .

As shown in FIGS. 4 and 8, the standing wall 22 of the outer plate 20 extends from the facing wall 21 in the rotation axis direction of the rotor 50 . As shown in FIGS. 3, 4, and 6 to 8, the flange 23 of the outer plate 20 extends perpendicularly to the rotation axis Ax of the rotor 50 from a portion of the vertical wall 22 opposite to the opposing wall 21. extended. The flange 23 is provided with an opening 26 that is shaped like a + sign (that is, shaped like a plus sign) when viewed from the axial direction. Therefore, the upright wall 22 and the flange 23 are shaped so as to border the plus sign-shaped opening 26 .

In the following description, of the flanges 23 of the outer plate 20, the radially outer portion of the + symbol-shaped end portion is referred to as a first flange 231, and the curved portion of the + symbol-shaped central portion is referred to as a second flange. It is sometimes called 232.

As shown in FIGS. 3, 4 and 9, the inner hub 30 is provided between the armature 10 and the outer plate 20. As shown in FIGS. The inner hub 30 has a tubular boss portion 31 and a plate portion 32 extending radially outward from the end portion of the boss portion 31 . A radially inner portion of the plate portion 32 and the boss portion 31 are made of metal. On the other hand, the radially outer portion of the plate portion 32 is made of resin. The inner hub 30 has a metal part and a resin part integrally formed by insert molding.

A female thread 33 is formed on the inner periphery of the boss portion 31 . The inner hub 30 is fixed to the end of the shaft 76 of the compressor 70 by screwing together the female thread 33 formed on the inner periphery of the boss portion 31 and the male thread 78 formed on the outer periphery of the shaft 76 of the compressor 70 . . This allows the inner hub 30 to transmit torque to the compressor 70 .

The plate portion 32 of the inner hub 30 is formed in the shape of a + sign. The plate portion 32 is provided between the flange 23 of the outer plate 20 and the armature 10 inside the standing wall 22 of the outer plate 20 . With respect to the inner hub 30 fixed to the shaft 76 of the compressor 70, the outer plate 20 and the armature 10 are provided so as to be movable relative to each other in the rotation axis direction.

The inner hub 30 also has an inner standing wall 34 facing the standing wall 22 of the outer plate 20 and an inner flange 35 facing the flange 23 of the outer plate 20 .
An inner vertical wall 34 of the inner hub 30 is provided substantially parallel to the vertical wall 22 of the outer plate 20 . A predetermined space is provided between the inner vertical wall 34 of the inner hub 30 and the vertical wall 22 of the outer plate 20 so that a cushioning portion of the elastic member 40, which will be described later, can be arranged.

The inner flange 35 of the inner hub 30 is provided substantially parallel to the flange 23 of the outer plate 20 . A predetermined space is also provided between the inner flange 35 of the inner hub 30 and the flange 23 of the outer plate 20 so that the urging portion of the elastic member 40, which will be described later, can be arranged.

In the following description, the portion of the inner flange 35 of the inner hub 30 that faces the first flange 231 of the outer plate 20 may be called a first inner flange 351. A portion of the inner flange 35 of the inner hub 30 that faces the second flange 232 of the outer plate 20 is sometimes called a second inner flange 352 .

As shown in FIGS. 3, 4 and 10, the elastic member 40 is shaped to correspond to the space between the outer plate 20 and the inner hub 30 and the space between the outer plate 20 and the armature 10. It is a highly durable rubber member. The elastic member 40 is fitted between the outer plate 20 and the inner hub 30 and between the outer plate 20 and the armature 10 in a compressed state.

The elastic member 40 has an urging portion 41 , a buffer portion 42 and a damping portion 43 . The biasing portion 41 is a portion arranged between the flange 23 of the outer plate 20 and the inner flange 35 of the inner hub 30 . The buffer portion 42 is a portion arranged between the upright wall 22 of the outer plate 20 and the inner upright wall 34 of the inner hub 30 . The damping portion 43 is a portion arranged between the facing wall 21 of the outer plate 20 and the armature 10 . Note that, in the following description, a portion of the biasing portion 41 of the elastic member 40 that is arranged between the first flange 231 and the first inner flange 351 may be referred to as a first biasing portion 411 . A portion of the biasing portion 41 of the elastic member 40 that is arranged between the second flange 232 and the second inner flange 352 is sometimes called a second biasing portion 412 .

The first biasing portion 411 or the second biasing portion 412 biases the flange 23 against the inner flange 35 to the side opposite to the rotor 50 . Therefore, as shown in FIG. 4 , when the electromagnetic coil 58 of the rotor 50 is not energized, the armature 10 is separated from the end surface 59 of the rotor 50 . At this time, the position of the armature 10 in the rotation axis direction is determined by the contact between the plate portion 32 of the inner hub 30 and the armature 10 . On the other hand, when the electromagnetic coil 58 is energized, magnetic flux flows through the magnetic circuit formed by the stator 57 , rotor 50 and armature 10 . Due to the magnetic attraction force generated between the rotor 50 and the armature 10 , the armature 10 is drawn toward the rotor 50 against the biasing force of the biasing portion 41 of the elastic member 40 and comes into contact with the end face 59 of the rotor 50 .

The cushioning portion 42 of the elastic member 40 is compressed between the surface of the vertical wall 22 of the outer plate 20 facing the rotational direction and the surface of the inner vertical wall 34 of the inner hub 30 facing the rotational direction. is embedded in the The buffer portion 42 absorbs torque fluctuations between the inner hub 30 and the outer plate 20 when torque is transmitted from the rotor 50 to the compressor 70 , and transmits torque from the outer plate 20 to the inner hub 30 in a cushioning manner. In order to increase durability against torque fluctuations, the height of the vertical wall 22 of the outer plate 20 (i.e., the distance in the direction of the rotational axis of the vertical wall 22) and the height of the buffer portion 42 of the elastic member 40 (i.e., the distance in the buffer portion 42) It is preferable to increase both the distances in the rotation axis direction.

The damping portion 43 of the elastic member 40 is fitted in a compressed state between the opposing wall 21 of the outer plate 20 and the armature 10 . The damping portion 43 is arranged across the inner ring portion 12 and the outer ring portion 11 of the armature 10 . That is, the damping portion 43 is pressed against the inner ring portion 12 and the outer ring portion 11 of the armature 10 by the facing wall 21 of the outer plate 20 . Therefore, when the electromagnetic coil 58 is energized, the damping portion 43 can suppress the vibration of the inner ring portion 12 and the outer ring portion 11 of the armature 10 and reduce the operation noise. The operating noise includes contact noise generated when the armature 10 contacts the rotor 50 when the electromagnetic coil 58 is energized, and resonance caused by vibration generated by slippage between the armature 10 and the rotor 50. Sound included.

In this embodiment, the damping portion 43 of the elastic member 40 has a thick portion 44 and a thin portion 45 . The thick portion 44 is a portion provided between the outer plate concave portion 25 and the armature 10 . The thick portion 44 is in contact with the armature 10 side surface of the outer plate recessed portion 25 and the outer plate recessed portion 25 side surface of the armature 10 , and is compressed between the outer plate recessed portion 25 and the armature 10 . provided in the state. On the other hand, the thin portion 45 is provided in a compressed state between the armature 10 and the portion 21 a of the opposing wall 21 that is connected to the standing wall 22 and its vicinity. The thin portion 45 is also provided in a compressed state between the portion of the opposing wall 21 surrounding the rivet 15 and the armature 10 .

It should be noted that, as described above, the rivets 15 that fix the outer plate 20 and the armature 10 are provided at positions close to the outer periphery of the outer plate 20 . Therefore, when the vibration damping portion 43 of the elastic member 40 is fitted between the opposing wall 21 of the outer plate 20 and the armature 10 in a compressed state, the elastic force of the vibration damping portion 43 causes the rivet portion of the opposing wall 21 to move. There is concern that the radially inner portion far from 15 may be deformed. In contrast, in the present embodiment, the outer plate recessed portion 25 enhances the rigidity of the facing wall 21, so deformation of the facing wall 21 is prevented. Therefore, the damping portion 43 of the elastic member 40 can be reliably pressed against the inner ring portion 12 and the outer ring portion 11 of the armature 10 by the opposing wall 21 . Therefore, the electromagnetic clutch 1 of the present embodiment can reliably suppress vibrations of the inner ring portion 12 and the outer ring portion 11 of the armature 10 and reduce operating noise.

Next, the operation of the electromagnetic clutch 1 will be explained.
As shown in FIG. 4 , when the electromagnetic coil 58 is not energized, the armature 10 is separated from the end surface 59 of the rotor 50 by the biasing force of the biasing portion 41 of the elastic member 40 . Therefore, the torque transmitted from the pulley 82 of the engine 80 to the rotor 50 via the belt 83 is not transmitted to the electromagnetic clutch 1 having the armature 10 , and the rotor 50 idles on the ball bearings 90 . Therefore, the compressor 70 is stopped.

On the other hand, as shown in FIG. 8, when the electromagnetic coil 58 is energized, magnetic flux flows through the magnetic circuit formed by the stator 57, rotor 50, and armature 10. At this time, in this embodiment, the magnetic flux leakage between the armature 10 and the outer plate 20 becomes negligibly small due to the outer plate concave portion 25 . Therefore, the amount of magnetic flux flowing through “inner ring portion 12 of armature 10—rotor central portion 502—outer ring portion 11 of armature 10” increases, and the magnetic attraction force between rotor 50 and armature 10 increases. Due to the magnetic attraction force, the armature 10 is drawn toward the rotor 50 against the biasing force of the biasing portion 41 of the elastic member 40 and comes into contact with the end surface 59 of the rotor 50 . The armature 10 is joined to the end surface 59 of the rotor 50 by frictional force. As a result, the torque transmitted from the engine 80 to the rotor 50 is transmitted in the order of rotor 50→armature 10→outer plate 20→elastic member 40→inner hub 30→shaft 76, and compressor 70 is driven.

Here, an electromagnetic clutch 100 of a comparative example will be described for comparison with the electromagnetic clutch 1 of the first embodiment described above.

FIG. 17 is a cross-sectional view showing part of the electromagnetic clutch 100 and part of the rotor 50 of the comparative example.
As shown in FIG. 17, the opposing wall 21 of the outer plate 20 included in the electromagnetic clutch 100 of the comparative example is not provided with the outer plate concave portion 25 . Therefore, the opposing wall 21 of the outer plate 20 is planar, and the distance D5 between the opposing wall 21 and the armature 10 is short. As a result, as indicated by the solid line M3 in FIG. 17, the amount of magnetic flux flowing through "inner ring portion 12 of armature 10--opposing wall 21 of outer plate 20--outer ring portion 11 of armature 10" (that is, magnetic flux leakage) increases. Therefore, as indicated by the solid line M1, a magnetic circuit consisting of "stator 57--rotor inner diameter portion 503--inner ring portion 12 of armature 10--rotor central portion 502--outer ring portion 11 of armature 10--rotor outer diameter portion 501--stator 57" is formed. The amount of magnetic flux that flows is reduced. As a result, in the electromagnetic clutch 100 of the comparative example, the magnetic attraction force between the rotor 50 and the armature 10 is weakened, and there is a risk that the torque transmission performance from the rotor 50 to the driven member will be deteriorated.

In the electromagnetic clutch 100 of the comparative example, in order to prevent magnetic flux leakage between the opposing wall 21 of the outer plate 20 and the armature 10, the damping portion 43 of the elastic member 40 is made thick overall, and the opposing wall 21 and the armature 10 are separated. It is conceivable to increase the distance D5 of . However, in this case, the height of the vertical wall 22 of the outer plate 20 (that is, the distance in the direction of the rotation axis of the vertical wall 22) is reduced. Along with this, the height of the cushioning portion 42 of the elastic member 40 (that is, the distance in the rotation axis direction of the cushioning portion 42) is also reduced. Therefore, there arises a problem that the durability against torque fluctuation is lowered.

Also, in the electromagnetic clutch 100 of the comparative example, the facing wall 21 of the outer plate 20 is not provided with the outer plate concave portion 25, so the rigidity of the facing wall 21 is lower than that of the first embodiment. Therefore, there is concern that the radially inner portion of the opposing wall 21 far from the rivet 15 may be deformed by the elastic force of the damping portion 43 of the elastic member 40 . When the opposing wall 21 of the outer plate 20 is deformed, the force with which the opposing wall 21 presses the damping portion 43 of the elastic member 40 against the inner ring portion 12 and the outer ring portion 11 of the armature 10 is weakened. Therefore, the vibration damping function of the inner ring portion 12 and the outer ring portion 11 of the armature 10 by the damping portion 43 of the elastic member 40 is deteriorated, and there is a possibility that the operation noise cannot be sufficiently reduced.

Compared with the electromagnetic clutch 100 of the comparative example, the electromagnetic clutch 1 of the first embodiment has the following effects.
(1) In the electromagnetic clutch 1 of the first embodiment, a distance D2 It has an outer plate concave portion 25 as a concave shape portion that distances the .
According to this, when the electromagnetic coil 58 is energized, it is possible to increase the magnetic resistance of the magnetic path formed by "the inner ring portion 12 of the armature 10--the opposing wall 21 of the outer plate 20--the outer ring portion 11 of the armature 10." Therefore, the magnetic flux leakage between the armature 10 and the outer plate 20 is reduced when the electromagnetic coil 58 is energized, and the amount of magnetic flux flowing through "the inner ring portion 12 of the armature 10 - the rotor center portion 502 - the outer ring portion 11 of the armature 10" increases. do. Therefore, the magnetic attraction force between the rotor 50 and the armature 10 is increased. As a result, the electromagnetic clutch 1 can improve the magnetic performance and improve the torque transmissibility from the rotor 50 to the compressor 70 .

(2) In the electromagnetic clutch 1 of the first embodiment, the damping portion 43 of the elastic member 40 is provided between the facing wall 21 of the outer plate 20 and the armature 10 . Since the rigidity of the opposing wall 21 of the outer plate 20 is increased by the outer plate concave portion 25, the opposing wall 21 reliably presses the damping portion 43 of the elastic member 40 against the inner ring portion 12 and the outer ring portion 11 of the armature 10. is possible. Therefore, the electromagnetic clutch 1 of the first embodiment can reduce operating noise by reliably suppressing vibrations of the inner ring portion 12 and the outer ring portion 11 of the armature 10 with the damping portion 43 of the elastic member 40 .

(3) Further, in the electromagnetic clutch 1 of the first embodiment, the damping portion 43 of the elastic member 40 as described in the description of the electromagnetic clutch 100 of the comparative example is made thicker overall, and the opposing wall 21 and the armature 10 are It is not configured to increase the distance D5 of . That is, the electromagnetic clutch 1 of the first embodiment is provided with the outer plate concave portion 25, so that the distance D1 between the armature 10 and the portion 21a where the opposing wall 21 and the standing wall 22 of the outer plate 20 are connected can be shortened. is possible. Therefore, in the electromagnetic clutch 1 of the first embodiment, the height of the buffer portion 42 of the elastic member 40 and the vertical wall 22 (that is, the distance in the direction of the rotation axis) can be reduced without increasing the size of the electromagnetic clutch 1 in the direction of the rotation axis. It is possible to make it larger. Therefore, the electromagnetic clutch 1 of the first embodiment can improve durability against torque fluctuations.

(4) In the electromagnetic clutch 1 of the first embodiment, the outer plate 20 is positioned across the inner ring portion 12 and the outer ring portion 11 of the armature 10 at a portion of the opposing wall 21 of the outer plate 20 that faces the long hole 13 of the armature 10 . A recess 25 is provided.
According to this, the magnetic resistance between the outer plate concave portion 25 and the inner ring portion 12 of the armature 10 can be increased, and the magnetic resistance between the outer plate concave portion 25 and the outer ring portion 11 of the armature 10 can be increased. It becomes possible. Therefore, the magnetic flux leakage between the armature 10 and the outer plate 20 can be reduced, and the magnetic attraction force between the rotor 50 and the armature 10 can be increased.

(5) The outer plate concave portion 25 provided in the electromagnetic clutch 1 of the first embodiment is formed by connecting the vertical wall 22 and the opposing wall 21 of the outer plate 20 and the rivets 15 that fix the outer plate 20 and the armature 10 together. located in the middle part.
According to this, it is possible to increase the rigidity of the portion of the facing wall 21 of the outer plate 20 between the portion where the standing wall 22 and the facing wall 21 are connected and the rivet 15 by the outer plate concave portion 25 . Therefore, the damping portion 43 of the elastic member 40 is reliably pressed against the inner ring portion 12 and the outer ring portion 11 of the armature 10 by the opposing wall 21 of the outer plate 20, thereby suppressing the vibration of the inner ring portion 12 and the outer ring portion 11. Sound can be reduced.

(6) The damping portion 43 of the elastic member 40 provided in the electromagnetic clutch 1 of the first embodiment has a thick portion 44 arranged between the outer plate concave portion 25 and the armature 10 . The thick portion 44 is in contact with the armature 10 side surface of the outer plate recessed portion 25 and the outer plate recessed portion 25 side surface of the armature 10 , and is compressed between the outer plate recessed portion 25 and the armature 10 . It is installed in the
According to this, by providing the thick portion 44 in the damping portion 43 of the elastic member 40, the function of damping the vibrations of the inner ring portion 12 and the outer ring portion 11 of the armature 10 is enhanced, and the operation noise is reliably reduced. can be done.

(Second embodiment)
A second embodiment will be described. 2nd Embodiment changes the position of the rivet 15, and the shape of the outer plate recessed part 25 with respect to 1st Embodiment, Since it is the same as that of 1st Embodiment about others, Only different parts will be explained.

As shown in FIG. 11, in the second embodiment, the rivet 15 for fixing the armature 10 and the outer plate 20 is positioned between the surface 22a of the upright wall 22 of the outer plate 20 facing the rotation direction and the outer plate concave portion 25. provided in the part. The rivet 15 is molded integrally with the armature 10, is inserted into an insertion hole 24 provided in the opposing wall 21 of the outer plate 20, and has its tip end crimped.

The outer plate recessed portion 25 is provided between the vertical walls 22, and is shaped like a fan when viewed from the rotation axis direction. Further, the outer plate recessed portion 25 is provided at a position other than the rivet 15 . The outer plate recessed portion 25 of the second embodiment has a larger area when viewed from the rotation axis direction than the outer plate recessed portion 25 described in the first embodiment. Therefore, in the second embodiment, the magnetic resistance between the outer plate concave portion 25 and the armature 10 is greater than in the first embodiment.

In the electromagnetic clutch 1 of the second embodiment described above, the rivet 15 is provided at a position close to the surface 22a of the standing wall 22 of the outer plate 20 facing the rotational direction, thereby ensuring a large area for the outer plate concave portion 25. It is possible. Therefore, when the electromagnetic coil 58 is energized, the magnetic flux leakage between the armature 10 and the outer plate 20 is further reduced, and the amount of magnetic flux flowing through "the inner ring portion 12 of the armature 10 - the rotor center portion 502 - the outer ring portion 11 of the armature 10" is reduced. It is possible to increase more. Therefore, the electromagnetic clutch 1 of the second embodiment can improve the magnetic performance as compared with the first embodiment, and can increase the magnetic attraction force between the rotor 50 and the armature 10 .

(Third Embodiment)
A third embodiment will be described. In the third embodiment, part of the configuration of the armature 10 and part of the configuration of the outer plate 20 are changed with respect to the first embodiment and the like, and the rest is the same as the first embodiment and the like. Therefore, only parts different from the first embodiment and the like will be described.

As shown in FIG. 12, in the third embodiment, an armature concave portion 16 is provided as a concave portion on the surface of the armature 10 on the outer plate 20 side. In addition, in the third embodiment, the outer plate concave portion 25 is not provided in the facing wall 21 of the outer plate 20 .

The armature recess 16 is provided in a portion of the armature 10 that includes the elongated hole 13 and is recessed so that the distance D3 from the facing wall 21 of the outer plate 20 increases. Specifically, the distance D3 between the opposing wall 21 of the outer plate 20 and the armature recess 16 is greater than the distance D1 between the portion of the armature 10 where the armature recess 16 is not provided and the opposing wall 21 of the outer plate 20. It's becoming As a result, the distance D3 between the armature concave portion 16 and the opposing wall 21 is increased, thereby increasing the magnetic resistance therebetween. Therefore, as indicated by the broken line M4 in FIG. Magnetic flux leakage between the outer plate 20 is reduced. Therefore, as indicated by the solid line M1, a magnetic circuit consisting of "stator 57--rotor inner diameter portion 503--inner ring portion 12 of armature 10--rotor central portion 502--armature 10 outer ring portion 11--rotor outer diameter portion 501--stator 57" is formed. The amount of magnetic flux flowing increases. Therefore, the magnetic attraction force between the rotor 50 and the armature 10 increases. As a result, the electromagnetic clutch 1 of the third embodiment can also improve the magnetic performance as in the first embodiment and the like, and the torque transmission from the rotor 50 to the compressor 70 can be enhanced.

The elastic member 40 provided in the electromagnetic clutch 1 of the third embodiment also has a thick portion 46 in the damping portion 43 . The thick portion 46 is in contact with the surface of the armature recess 16 on the side of the opposing wall 21 and the surface of the opposing wall 21 on the side of the armature recess 16 , and is compressed between the armature recess 16 and the opposing wall 21 . provided in the state. Therefore, the vibration of the inner ring portion 12 and the outer ring portion 11 of the armature 10 can be suppressed by the thick portion 46 of the damping portion 43 of the elastic member 40 . Therefore, the electromagnetic clutch 1 of the third embodiment can also reliably reduce operating noise, like the first embodiment.

(Fourth embodiment)
A fourth embodiment will be described. In the fourth embodiment, part of the configuration of the armature 10 and part of the configuration of the outer plate 20 are changed with respect to the first embodiment and the like, and the rest is the same as the first embodiment and the like. Therefore, only parts different from the first embodiment and the like will be described.

As shown in FIGS. 13 and 14, in the fourth embodiment, magnetic resistance holes 27 are provided in the opposing wall 21 of the outer plate 20. As shown in FIGS. In the fourth embodiment, the outer plate recessed portion 25 and the armature recessed portion 16 as recessed portions are not provided in the outer plate 20 and the armature 10 .

As shown in FIG. 13, the magnetic resistance hole 27 is provided at a position facing the elongated hole 13 of the armature 10 . Further, as shown in FIG. 14, the magnetic resistance hole 27 is formed in the facing wall 21 of the outer plate 20 in an arc shape centered on the rotation axis Ax. The magnetic resistance hole 27 divides the opposing wall 21 into a radially inner portion 21c and a radially outer portion 21d. The magnetic resistance hole 27 has a function of increasing magnetic resistance between a radially inner portion 21c of the facing wall 21 and a radially outer portion 21d of the facing wall 21 . Therefore, as indicated by the dashed line M5 in FIG. 13, the amount of magnetic flux flowing through “the inner ring portion 12 of the armature 10—the opposing wall 21 of the outer plate 20—the outer ring portion 11 of the armature 10” becomes negligibly small. Magnetic flux leakage between the outer plate 20 is reduced. Therefore, as indicated by the solid line M1, a magnetic circuit consisting of "stator 57--rotor inner diameter portion 503--inner ring portion 12 of armature 10--rotor central portion 502--armature 10 outer ring portion 11--rotor outer diameter portion 501--stator 57" is formed. The amount of magnetic flux flowing increases. Therefore, the magnetic attraction force between the rotor 50 and the armature 10 increases. As a result, the electromagnetic clutch 1 of the fourth embodiment can also improve the magnetic performance as in the first embodiment and the like, and can improve the torque transmissibility from the rotor 50 to the compressor 70 .

(Fifth embodiment)
A fifth embodiment will be described. 5th Embodiment is the structure which combined 1st Embodiment and 4th Embodiment.

As shown in FIGS. 15 and 16, in the fifth embodiment, an outer plate recessed portion 25 is provided in the facing wall 21 of the outer plate 20 . Furthermore, in the fifth embodiment, a magnetic resistance hole 27 is provided in the outer plate concave portion 25 . As shown in FIG. 15, the magnetic resistance hole 27 is provided at a position facing the elongated hole 13 of the armature 10. As shown in FIG. Further, as shown in FIG. 16 , the magnetic resistance hole 27 is formed in an arcuate shape around the rotation axis Ax at a position including the outer plate concave portion 25 in the facing wall 21 of the outer plate 20 .

In the fifth embodiment, the facing wall 21 of the outer plate 20 is provided with the outer plate recessed portion 25 and the magnetic resistance hole 27 . Therefore, as indicated by the dashed line M6 in FIG. 15, the amount of magnetic flux flowing through "the inner ring portion 12 of the armature 10--the opposing wall 21 of the outer plate 20--the outer ring portion 11 of the armature 10" can be made extremely small. That is, magnetic flux leakage between the armature 10 and the outer plate 20 can be further reduced. Therefore, as indicated by the solid line M1, a magnetic circuit consisting of "stator 57--rotor inner diameter portion 503--inner ring portion 12 of armature 10--rotor central portion 502--armature 10 outer ring portion 11--rotor outer diameter portion 501--stator 57" is formed. The amount of magnetic flux that flows can be further increased. Therefore, the magnetic attraction force between the rotor 50 and the armature 10 can be increased. As a result, the electromagnetic clutch 1 of the fifth embodiment can further improve the magnetic performance and improve torque transmissibility from the rotor 50 to the compressor 70 .

(Other embodiments)
(1) In each of the above embodiments, the compressor 70 was exemplified as the driven body to which the electromagnetic clutch 1 transmits torque. is possible.

(2) In each of the above-described embodiments, the outer plate 20 of the electromagnetic clutch 1 is provided with the + sign-shaped opening 26. However, the shape of the opening 26 provided in the outer plate 20 is not limited to this. Any shape such as a shape, * shape, or the like can be used. In that case, the shape of the inner hub 30 and the elastic member 40 can also be made into various shapes according to the shape of the opening 26 .

(3) In the first, second, and fifth embodiments, the electromagnetic clutch 1 has the outer plate concave portion 25 as the concave portion. Although it was set as the structure provided with, it is not restricted to it. For example, the electromagnetic clutch 1 may be configured to include both the outer plate recess 25 and the armature recess 16 as recessed portions, and may further be configured to include the magnetic resistance hole 27 .

The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate. Moreover, the above-described embodiments are not unrelated to each other, and can be appropriately combined unless the combination is clearly impossible. Further, in each of the above-described embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential, unless it is explicitly stated that they are essential, or they are clearly considered essential in principle. stomach. In addition, in each of the above-described embodiments, when numerical values such as the number, numerical value, amount, range, etc. of the constituent elements of the embodiment are mentioned, when it is explicitly stated that they are particularly essential, and when they are clearly limited to a specific number in principle It is not limited to that specific number, except when In addition, in each of the above-described embodiments, when referring to the shape, positional relationship, etc. of the constituent elements, the shape, It is not limited to the positional relationship or the like.

Claims

An electromagnetic clutch that switches between a state of transmitting torque from a rotor (50) having an electromagnetic coil (58) and rotating about a predetermined rotation axis (Ax) to a driven body (70) and a state of not transmitting it,
An outer ring portion (11) provided on one side of the rotor in the rotation axis direction and facing the rotor and provided on the outer peripheral side, an inner ring portion (12) provided on the rotation shaft side of the outer ring portion, and an armature (10) having an elongated hole (13) extending in an arc shape in the circumferential direction between the outer ring portion and the inner ring portion and capable of coming into contact with the rotor by magnetic attraction force generated by the electromagnetic coil;
A facing wall (21) fixed to the armature and facing a surface of the armature opposite to the rotor, an upright wall (22) extending from the facing wall in the rotation axis direction of the rotor, and an outer plate (20) having a flange (23) extending perpendicularly to the rotation axis of the rotor from a portion on the opposite side of the opposing wall and rotating together with the armature;
An inner hub (30) provided between the armature and the outer plate, having an inner standing wall (34) facing the standing wall and an inner flange (35) facing the flange, and transmitting torque to the driven body. When,
A biasing portion (41) provided between the inner flanges and a cushioning portion (42) provided between a surface of the vertical wall facing the rotational direction and a surface of the internal vertical wall facing the rotational direction. and an elastic member (40) having a damping portion (43) provided between the opposing wall and the armature,
At least one of the opposing wall and the armature has a distance (D2 , D3) are provided with recessed features (16, 25).
The recessed portion is provided at a portion of the opposing wall that faces the elongated hole of the armature and straddles the inner ring portion and the outer ring portion of the armature, and the distance (D2) from the armature is large. 2. An electromagnetic clutch according to claim 1, wherein the outer plate recess (25) is recessed to form a .
further comprising a rivet (15) fixing the opposing wall of the outer plate and the armature;
3. The electromagnetic clutch according to claim 2, wherein said outer plate recess is provided at a portion of said outer plate between a portion where said standing wall and said opposing wall are connected and a portion where said rivet is provided.
further comprising a rivet (15) fixing the opposing wall of the outer plate and the armature;
3. The electromagnetic clutch according to claim 2, wherein said rivet is provided at a portion of said outer plate between a surface (22a) of said standing wall facing the rotational direction and said outer plate recess.
The damping portion is in contact with a surface of the outer plate recess on the side of the armature and a surface of the armature on the side of the outer plate recess, and is compressed between the outer plate recess and the armature. 5. Electromagnetic clutch according to any one of claims 2 to 4, characterized in that it has a thickened portion (44) provided with .
2. The electromagnetic wave according to claim 1, wherein said recessed portion is an armature recessed portion (16) provided in a portion of said armature including said elongated hole and recessed so as to increase a distance (D3) from said opposing wall. clutch.
The damping portion is in contact with a surface of the recessed armature on the side of the opposing wall and a surface of the recessed portion of the armature on the side of the recessed armature, and is compressed between the recessed armature and the opposing wall. 7. Electromagnetic clutch according to claim 6, having a thickened portion (46) provided.
An electromagnetic clutch that switches between a state of transmitting torque from a rotor (50) having an electromagnetic coil (58) and rotating about a predetermined rotation axis (Ax) to a driven body (70) and a state of not transmitting it,
An outer ring portion (11) provided on one side of the rotor in the rotation axis direction and facing the rotor and provided on the outer peripheral side, an inner ring portion (12) provided on the rotation shaft side of the outer ring portion, and an armature (10) having an elongated hole (13) extending in an arc shape in the circumferential direction between the outer ring portion and the inner ring portion and capable of coming into contact with the rotor by magnetic attraction force generated by the electromagnetic coil;
A facing wall (21) fixed to the armature and facing a surface of the armature opposite to the rotor, an upright wall (22) extending from the facing wall in the rotation axis direction of the rotor, and an outer plate (20) having a flange (23) extending perpendicularly to the rotation axis of the rotor from a portion on the opposite side of the opposing wall and rotating together with the armature;
An inner hub (30) provided between the armature and the outer plate, having an inner standing wall (34) facing the standing wall and an inner flange (35) facing the flange, and transmitting torque to the driven body. When,
A biasing portion (41) provided between the flange and the inner flange, and a cushioning portion (42) provided between a surface of the vertical wall facing the rotational direction and a surface of the internal vertical wall facing the rotational direction. and an elastic member (40) having a damping portion (43) provided between the opposing wall and the armature,
The opposing wall is divided into a radially inner portion (21c) and a radially outer portion (21d). An electromagnetic clutch, wherein a magnetic resistance hole (27) for increasing magnetic resistance with a radially outer portion is provided at a position facing the elongated hole of the armature.
The opposing wall is arranged such that the distance (D2) between the armature and the opposing wall is greater than the distance (D1) between the armature and the portion (21a) where the opposing wall and the standing wall are connected. 9. An electromagnetic clutch according to claim 8, wherein a recessed outer plate recess (25) is provided and said magnetic resistance hole is provided in said opposing wall of said outer plate at a position including said outer plate recess.