JP2000205303A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic clutch of coil rotating type having a simple structure for earthing. SOLUTION: A solenoid coil 2 is placed at a rotor 1 in such a manner that the solenoid coil 2 is electrically insulated, and a sliding current-carrying mechanism is provided which includes slip rings 19, 20 and brushes 22, 23 which are slidably pressed into contact with the slip rings 19, 20, respectively. Through the sliding current-carrying mechanism, the solenoid coil 2 is energized, and the slip rings 19, 20 are held by the rotor 1 via a slip ring holding member 18, while the brushes 22, 23 are held by a boss part 6a via a brush holding member 24. The brush 23 on the negative electrode side is earthed in such a manner that the brush 23 directly comes into contact with the boss part 6a. Since the brush 23 on the negative electrode side is earthed to directly come into contact with the boss part 6a, extension of wiring for earthing to the exterior is not necessary. Accordingly, a structure for a line connector or the like for extending the wiring from the brush 23 on the negative electrode side to the exterior is not required, which results in a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch for interrupting power transmission, and is suitable for driving a compressor of a refrigeration cycle of an air conditioner for a vehicle.

[0002]

2. Description of the Related Art In this type of conventional electromagnetic clutch, a coil fixed type in which an electromagnetic coil for generating an electromagnetic attraction force is installed on a fixed member side is generally used. In this coil fixed type, since the electromagnetic coil is on the fixed member side,
There is an advantage that the current supply path to the electromagnetic coil can be simply configured without requiring a special current supply member.

However, on the other hand, since the electromagnetic coil is installed on the fixed member side, the magnetic circuit through which the magnetic flux from the electromagnetic coil passes passes through the fixed member, the rotating member, and the armature magnetically attracted to the rotating member. It becomes a circuit, and there is a gap between each of the three. As a result, the magnetic loss increases and the magnetic efficiency decreases, resulting in an increase in the size of the electromagnetic coil or an increase in the power consumption of the electromagnetic coil.

Therefore, a coil rotating type in which an electromagnetic coil is installed on the rotating member side has been proposed in Japanese Patent Application No. 10-239028. In this coil-rotating type, since the magnetic circuit can be constituted only by the rotating member and the armature magnetically attracted to the rotating member, the magnetic loss is extremely small, and the magnetic efficiency can be greatly improved as compared with the fixed coil type. There are advantages.

In the above prior art, attention is paid to the inner peripheral space of the cylindrical boss portion of the fixed member housing, and a slip ring and a brush which presses and slides on the slip ring are provided on the inner peripheral side of the boss portion. A sliding energizing mechanism including
The electromagnetic coil is energized through the sliding energizing mechanism. As a result, even in the case of the coil rotating type, the coil conduction path can be formed with almost no increase in the axial dimension.

[0006]

In the above prior art, lead wires are respectively drawn from the positive and negative brushes, and the lead wires are connected to connection terminals provided inside an insulating connector. The grounding of one brush is performed by being connected to an external control circuit from this connection terminal. As described above, in the above-described related art, there is a problem that the wiring has to be drawn out for grounding, and the structure is complicated.

Further, in the above-mentioned prior art, the brush must be arranged in a limited space of the inner peripheral side space of the boss portion and the wiring must be drawn out, so that the thickness of the brush is limited, and the strength and strength of the brush are reduced. Life was sacrificed. The present invention has been made in view of the above problems, and an object of the present invention is to provide a coil rotating type electromagnetic clutch having a simple structure for grounding.

Another object of the present invention is to improve the strength and life of a brush in a coil rotating type electromagnetic clutch. Another object of the present invention is to ensure grounding in a coil rotation type electromagnetic clutch.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, an electromagnetic coil (2) is arranged on a rotating member (1) in an electrically insulated manner, and a slip ring (19, 20) is provided. ) And a brush (22, 23) that slides in pressure contact with the slip ring (19, 20), and the electromagnetic coil (2) passes through the sliding current mechanism.
The slip rings (19, 20) are held by the rotating member (1) via the slip ring holding member (18), and the brushes (22, 23) are fixed via the brush holding member (24). The brush is held by the member (6a), and one of the brushes (22, 23) is connected to the fixing member (6, 6a) and grounded.

According to this, one of the brushes (22, 23) has a fixed member (6, 6) which is a part of the body of the electromagnetic clutch.
Since it is connected to (a) and grounded, there is no need to draw out the wiring for grounding to the outside. Therefore, the configuration of a connector or the like for drawing out the wiring (28) from one of the brushes (22, 23) to the outside becomes unnecessary, and the configuration is simplified.

According to a second aspect of the present invention, one of the brushes (22, 23) is in direct contact with the fixing member (6, 6a) and is grounded. According to this, one brush (22, 23) is directly fixed to the fixing member (6,
6a), wiring for grounding is not required, and the configuration is further simplified. The invention according to claim 3 is characterized in that one of the brushes (22, 23) is pressed against the fixing member (6, 6a) by the elastic pressing member (45) and is in direct contact therewith. According to this, contact between one of the brushes (22, 23) and the fixing member (6, 6a) is ensured.

According to the invention described in claim 4, the fixing member is
A rotary shaft (13) having a boss (6a) that projects cylindrically outward from the housing (6) of the rotary machine (5) in the axial direction;
Is disposed at the center of the boss (6a), and the brush holding member (24) is connected to the inner peripheral side of the boss (6a) and the rotating shaft (1).
3), the brush holding member (24) is provided with a storage portion (24b) for storing the one brush (23), and the storage portion (24b) is formed in the brush holding member (24). (24b) has an opening (24c) on the outer diameter side, and one brush (23) has an opening (24c) in the storage portion (24b) on the inner diameter side (6c) of the boss (6a).
It is characterized by being in contact with.

According to this, the brushes (22, 23) are arranged in the space (21) on the inner peripheral side of the boss (6a). Since the wiring for grounding the one brush (23) is unnecessary, the space (21) on the inner peripheral side of the boss (6a) can be effectively used. One of the brushes (23) is housed in a housing portion (24b) on the outer diameter side of the brush holding member (24), and the outer diameter side is in contact with the inner diameter side (6c) of the boss (6a). . Therefore, one of the brushes (23) can be expanded to the outer diameter side so as to directly contact the inner diameter side (6c) of the boss portion (6a).
3) The thickness of 3) or more can be secured. Therefore, the predetermined strength of the one brush (23) can be secured, and the life of the one brush (23) can be improved.

According to the fifth aspect of the present invention, the storage portion (24
The width b in the circumferential direction is tapered so as to decrease from the inner diameter side to the outer diameter side of the brush holding member (24), and one of the brushes (23) is provided in the housing portion (24).
The storage portion (24) is formed in a shape corresponding to the shape of (b).
b). According to this, the shape of the one brush (23) and the storage portion (24b) is formed so that the circumferential width becomes smaller as going toward the outer diameter side, so that the one brush (23) is stored in the storage portion ( 24b) and is stably held without falling out.
Therefore, when manufacturing the electromagnetic clutch, the brush (22,
The assembly of the brush holding member (24) holding the 23) in the boss (6a) is facilitated.

In the invention according to claim 6, one of the brushes (23) is connected to the fixing member (6,
6a) and is grounded. Also in this case, the configuration such as a connector for drawing out the lead wire (28) from one brush (23) to the outside becomes unnecessary, and the configuration is simplified. Note that the reference numerals in parentheses described above indicate the correspondence with specific means described in the embodiment described later.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. (First Embodiment) FIGS. 1 to 3 show a first embodiment of the present invention. Reference numeral 1 denotes a drive-side rotor, a pulley portion 1 having a multiple V-groove on the outer periphery of which a multiple V-belt is engaged.
a are joined together. The drive-side rotor 1 is a drive-side rotating member that rotates by receiving torque from an automobile engine via a belt (not shown), and is made of an iron-based metal (ferromagnetic material) such as low carbon steel and has a U-shaped cross section. In a double ring shape. The inner cylindrical portion 1 of the driving rotor 1
b and an outer cylindrical portion 1c, an annular concave portion 1d is formed.
e is formed.

2 is an electromagnetic coil for generating an electromagnetic attraction force.
It is installed in the concave portion 1 d of the driving-side rotor 1. This electromagnetic coil 2 is wound on a resin winding frame 2a,
The resin member 3 molded in the concave portion 1d is insulated and fixed to the concave portion 1d. Therefore, the electromagnetic coil 2 rotates integrally with the drive-side rotor 1. Reference numeral 4 denotes a friction plate made of an iron-based metal (ferromagnetic material) such as low-carbon steel, which has a substantially ring-like shape, and a plurality of radially projecting portions 4a at the ring-shaped circumferential direction. And a projection 4b in the outer diameter direction is integrally formed. The friction plate 4 is supported and fixed to the axial ends (left ends in FIG. 1) of the inner cylindrical portion 1b and the outer cylindrical portion 1c of the rotor 1 at the plurality of projections 4a and projections 4b. You.

Reference numeral 5 denotes a compressor which is a driven device (rotary machine), and reference numeral 6 denotes a front housing (fixed member) of the compressor 5 located on the electromagnetic clutch side. The front housing 6 is made of an aluminum-based metal, and has a boss (fixing member) 6 that protrudes cylindrically outward in the axial direction at the center thereof.
a is integrally formed. Here, the compressor 5 is for compressing a refrigerant in a refrigeration cycle of an air conditioner for a vehicle, and may be any type such as a known swash plate type, a vane type, and a scroll type.

Reference numeral 7 denotes a bearing for rotatably supporting the driving-side rotor 1 on a boss 6a of the front housing 6. In this embodiment, the bearing 7 includes an outer ring 7a fixed to the inner peripheral surface of the driving-side rotor 1. Inner ring 7 fixed to the outer peripheral surface of boss 6a
and a ball bearing 7b rotatably held between the two 7a and 7b.

Reference numeral 8 denotes a friction surface 1e of the rotor 1 and a friction plate 4
The armature is disposed opposite to the armature, and is formed of an iron-based metal (ferromagnetic material) in a ring-shaped flat plate shape. When the electromagnetic coil 2 is not energized, the armature 8 serves as the friction surface 1 of the rotor 1.
The plate spring (elastic connecting member) 9 is held at a position (a position shown in FIG. 1) at a predetermined minute distance from e.

The leaf springs 9 are in the form of elongated thin plates, and a plurality of leaf springs 9 are arranged in the circumferential direction of the armature 8. One end of each leaf spring 9 is connected to the armature 8 by a rivet 10a. Is connected to the hub 11 by a rivet 10b. The hub 11 is formed of a ferrous metal into a shape having a disk portion 11a extending in a radial direction and a central cylindrical portion 11b, and a stopper member made of an elastic material such as rubber is provided on an outer peripheral side of the disk portion 11a. The stopper 12 defines the axial position of the armature 8 (the position when the coil is not energized). Further, the armature 8 is pressed in the axial direction (toward the rotor 1) by the thickness of the stopper member 12 from the surface of the disk portion 11a of the hub 11, and the leaf spring 9 is elastically deformed. 9 generates a spring force, and the spring force holds the armature 8 at a predetermined axial position when the clutch is disconnected.

The center cylindrical portion 11b of the hub 11 is
And is fitted to the rotating shaft 13 by a spline connection or the like. And the tip male screw part 13a of the rotating shaft 13
The nut 11 is screwed into the hub 11 to rotate the hub 11
3 is integrally connected. Reference numeral 15 denotes a shaft sealing device for preventing lubricating oil, refrigerant, and the like inside the compressor 5 from leaking outside.

Next, a description will be given of a configuration of a current supply path to the electromagnetic coil 2 which rotates together with the rotor 1. In this embodiment,
A sliding energizing mechanism having slip rings 19, 20 and brushes 22, 23 is arranged on the inner peripheral side of the compressor boss 6a supporting the bearing 7, thereby forming an energizing path. The layout of the sliding energizing mechanism is specifically configured as follows. In the concave portion 1d of the rotor 1, the winding start end and the winding end of the electromagnetic coil 2 are taken out from the winding frame 2a toward the friction plate 4 (the armature 8 side), and one of the two ends is connected to a positive lead wire. 16 and the other end is connected to a lead wire 17 on the negative electrode side. FIG.
In this example, the two lead wires 16, 17 are arranged at symmetrical positions approximately 180 ° apart in the circumferential direction of the clutch.

On the inner peripheral side of the rotor 1, there is arranged a slip ring holding member 18 formed of an electrical insulating material such as resin and formed into a ring shape extending in the radial direction of the rotor. The holding member 18 is for holding two slip rings 19 and 20 on the positive electrode side and the negative electrode side. In this example, as shown in an enlarged view in FIG. 2, the relationship is set such that the diameter of the positive-electrode-side slip ring 19 <the diameter of the negative-electrode-side slip ring 20, and these two slip rings 19, 20 are concentrically arranged and held. The member 18 is insert-molded.

The outer peripheral portion 18a of the slip ring holding member 18 is fitted and fixed (for example, bonded and fixed) to a fitting concave groove (not shown) formed in the inner peripheral cylindrical portion 1b of the rotor 1. Thereby, the slip ring holding member 18 can be integrated with the inner peripheral cylindrical portion 1b of the rotor 1, and the slip ring holding member 18 rotates integrally with the rotor 1. The two slip rings 19 and 20 are made of a conductive metal such as copper.
9 has a terminal piece 19a on the positive electrode side, and a negative side slip piece 20a on the negative side slip ring 20 located on the outer peripheral side.
Are integrally formed by a method such as cutting and pressing. Here, the terminal piece 19a on the positive electrode side and the terminal piece 20a on the negative electrode side are arranged at symmetrical positions approximately 180 ° apart in the circumferential direction of the clutch.

The positive terminal strip 19a extends outwardly from the outer peripheral portion of the positive slip ring 19 and then integrally has a bent portion 19b which is bent in the axial direction toward the inner peripheral side of the armature 8. . Then, the end of the lead wire 16 on the positive electrode side is mechanically caulked and joined to the bent portion 19b, and then soldered, so that the positive terminal piece 19a and the lead wire 16 on the positive electrode side are mechanically and electrically connected. Electrically coupled.

The negative terminal piece 20a also has a similar bent portion 20b, and the lead wire 17 on the negative electrode side is mechanically and electrically connected to the bent portion 20b by the same means. . An electrical insulating material (such as an insulating varnish) is applied to the surface of the joint between the bent portions 19b and 20b of the terminal strips 19a and 20a and the lead wires 16 and 17 to achieve electrical insulation.

On the other hand, a cylindrical space 21 is formed between the central cylindrical portion 11b of the hub 11 fixed to the rotating shaft 13 of the compressor 5 and the inner peripheral surface of the boss portion 6a. The brushes 21, 23 on the positive electrode side and the negative electrode side, and a holding member 24 for the brushes 22, 23 are arranged on 21. FIG. 3 is a view showing the brushes 22, 23, the brush holding member 24 and the boss 6a, and FIG. 3 is a front view as viewed from the left side of FIG. The brush holding member 24 is formed of an electrical insulating material such as a resin, and has a ring-shaped bottom surface 24h. As shown in FIG. 3, two brush storage recesses 24a and 24b having an arc-shaped cross section are formed at symmetrical positions approximately 180 ° apart in the circumferential direction of the brush holding member 24.
As shown in FIG. 1, the brush storage recesses 24a and 24b are formed in a shape having an axial dimension (depth) covering substantially the entire axial dimension of the brush holding member 24.

The brush accommodating recess 24a accommodating the brush 22 on the positive electrode side has substantially equal arc lengths on the inner and outer peripheral sides, and is surrounded by insulating walls on all sides in the radial and circumferential directions. Have been. On the other hand, the brush accommodating recess 24b for accommodating the brush 23 on the negative electrode side is formed as an axial groove on the outer diameter side surface of the brush holding member 24, and the opening 2 is formed on the outer diameter side.
4c is formed. This negative side brush storage recess 24
The circumferential width of the groove b is tapered so as to decrease from the inner diameter side to the outer diameter side of the brush holding member 24. A concave portion 44 is further provided in this groove, and the concave portion 44 has a negative-side brush housing concave portion 24b.
A leaf spring 45 is disposed as an elastic pressing member that presses the brush 23 housed in the groove in the outer diameter direction.

The brushes 22 and 23 are formed in a sectional shape along the brush accommodating recesses 24a and 24b. The positive brush 22 is accommodated in one of the brush accommodating recesses 24a so as to be slidable in the axial direction. A coil spring 25 is disposed as an elastic pressing member between one end of the brush 22 and the bottom of the brush housing recess 24a. Therefore, the other end of the positive brush 22 is always pressed against the positive slip ring 19 by the spring force of the coil spring 25.

The brush 23 on the negative electrode side is axially slidably accommodated in the other brush receiving recess 24b, and has an elasticity between one end of the brush 23 on the negative electrode side and the bottom surface of the brush receiving recess 24b. A coil spring 26 is arranged as a pressing member. Therefore, the other end of the brush 23 on the negative electrode side is always pressed against the slip ring 20 on the negative electrode side by the spring force of the coil spring 26. The leaf spring 45 presses the brush 23 on the negative electrode side in the outer diameter direction of the brush housing recess 24b. Therefore, the brush 23 has an outer diameter
It protrudes from the opening 24c and is in direct contact with the boss 6a.

A projection 24f extending in the axial direction is formed on the outer peripheral surface of the brush holding member 24 where the brush accommodating recess 24a is formed. In addition, the brush storage recess 2
The protrusion 23a extending in the axial direction is formed by projecting at a symmetrical position 180 ° apart from the protrusion 24f also by the outer peripheral surface of the brush 23 housed in the brush 4b. On the other hand, two recesses 6b and 6c into which the two protrusions 24f and 23a are fitted are formed on the inner peripheral surface of the boss 6a. Therefore, the two projections 24f, 23a and the two recesses 6b, 6c
, The brush holding member 24 is connected to the boss portion 6a.
Are positioned and held in the rotational direction on the inner peripheral surface.

One end of a positive electrode side brush 22 is electrically connected to one end of a positive electrode side lead wire (pigtail) 27. The other end of this lead wire 27 is a brush housing recess 24a.
Of the brush holding member 24
Out of the compressor 5 side.
A terminal piece 29 on the positive electrode side is integrally formed on the bottom surface 24h of the brush holding member 24 by insert molding. The terminal strip 29 is made of a conductive metal such as copper or aluminum, and is provided on both sides of the bottom surface 24h (that is, on the side of the brushes 22 and 23 shown in FIG. 3 and on the back side of the paper of FIG. 3). Side surface).

The terminal piece 29 is, as shown in FIG.
Is arranged relatively close to the place of the arrangement. Terminal strip 2
9, a bent portion 29a formed on the surface on the compressor 5 side
The other end of the lead wire 27 from the positive brush 22 is mechanically and electrically connected by caulking and soldering. Further, a second bent portion 29b is formed on the surface of the terminal piece 29 on the positive electrode side on the side of the brushes 22 and 23, and the lead wire 31 for connecting an external circuit is formed on the bent portion 29b.
Are mechanically and electrically connected by swaging and soldering. The lead wire 31 penetrates through the hole 24 e of the bottom surface 24 h of the brush holding member 24 and
Take out on the side surface.

As described above, the brush 23 on the negative electrode side
By directly contacting the boss portion 6a, the terminal piece 30 on the negative electrode side is directly grounded to the vehicle body via the front housing 6 made of metal (aluminum). The positive lead 31 is wired on the outer surface of the front housing 6 of the compressor 5 and connected to an external control circuit (not shown) of the vehicle air conditioner. The positive lead 31 is connected to a vehicle-mounted power supply battery (not shown) via a relay contact (not shown) that is opened and closed by an external control circuit.

Next, the operation of the above configuration will be described.
Since the rotor 1 is rotatably supported on the outer peripheral surface of the boss 6a of the front housing 6 by the bearing 7,
When an automobile engine (not shown) is operated, the rotation of the crank pulley of the engine is transmitted to the pulley 1a via a belt (not shown), and the rotor 1 and the electromagnetic coil 2 constantly rotate.

As the rotor 1 and the electromagnetic coil 2 rotate, the lead wires 16 and 17 and the slip ring holding member 1
8, and the slip rings 19, 20 rotate together. On the other hand, the brushes 22 and 23 and the brush holding member 2
4. The coil springs 25 and 26 are all bosses 6a.
It is held on the side and fixed. Accordingly, one end faces in the axial direction of the brushes 22 and 23 are pressed against the rotating slip rings 19 and 20 by the spring force of the coil springs 25 and 26 and slide.

In order to operate the compressor 5 in the above state, when the relay contact is closed by the control circuit, the voltage of the vehicle-mounted power supply battery is increased by the above members (16, 17, 19,
20, 27, 29, and 31) are applied to the electromagnetic coil 2 through a current-carrying path, and a current flows through the electromagnetic coil 2. Then, a magnetic flux flows through the magnetic circuit formed between the rotor 1 and the friction plate 4 and the armature 8, so that an electromagnetic attraction force is generated between the friction surface 1e of the rotor 1 and the friction plate 4 and the armature 8. Thereby, the armature 8 is attracted and attracted to the friction surface 1e of the rotor 1 and the friction plate 4 against the axial elastic force of the plate spring 9 (force in the left direction in FIG. 1).

As a result, the rotor 1 and the armature 8 rotate integrally, and the armature 8 further rotates integrally with the hub 11 via the leaf spring 9 and the rivets 10a and 10b. Therefore, the rotation shaft 13 of the compressor 5 is
The rotation of the rotor 1 is transmitted to the compressor and the compressor 5 operates. On the other hand, when the compressor 5 is stopped, the relay contact is opened by the control circuit to cut off the power supply to the electromagnetic coil 2. As a result, the electromagnetic attraction force disappears, so that the armature 8
Is the friction surface 1e of the rotor 1 due to the axial elastic force of the leaf spring 9.
Also, the compressor 5 is stopped because the rotation transmission to the rotary shaft 13 of the compressor 5 is interrupted by separating from the friction plate 4.

In this embodiment, in a coil-rotating type in which the negative brush 23 is disposed on the inner peripheral side of the boss 6a, the brush 23 is directly contacted with the boss 6a and grounded. Therefore, a lead wire from the brush 23 on the ground side is not required, and the configuration is simplified. Negative electrode side brush 23
Are pressed from the inner peripheral side toward the outer peripheral side by the leaf spring 45. Therefore, the negative brush 23 and the boss 6a
Contact can be assured.

Further, since the wiring for grounding can be omitted, the space on the inner peripheral side of the boss 6a can be effectively used, and the brush 23 can be externally brought into direct contact with the inner diameter side of the boss 6a. The brush 23 can be extended to the radial side.
Can secure a predetermined thickness or more. Therefore, the predetermined strength of the brush 23 can be secured, and the life of the brush 23 can be improved.

The circumferential width of the groove of the brush accommodating recess 24b for accommodating the brush 23 on the negative electrode side is formed in a tapered shape such that it decreases from the inner diameter side to the outer diameter side of the brush holding member 24. Have been. Also, the negative brush 23
Is also formed in a cross-sectional shape along the brush housing recess 24b. In this way, the negative brush 23 and the brush receiving recess 24b are formed so that the circumferential width becomes smaller as the shape goes toward the outer diameter side, so that the negative brush 23 does not come out of the brush receiving recess 24b. It is kept stable. Therefore, when manufacturing the electromagnetic clutch, the brush 2
The brush holding member 24 holding the members 2 and 23 is connected to the boss 6a.
It is easy to assemble inside.

A recess 6c having a shape corresponding to the projection 23a of the negative brush 23 is formed on the inner peripheral surface of the boss 6a, and the projection 23a is fitted therein. Therefore, the negative brush 23 can be brought into contact with the boss 6a not only on the outer peripheral side surface but also on the tapered surface that is the circumferential side surface, so that the negative brush 23 and the boss portion 6a can be reliably electrically connected. . (Second Embodiment) FIGS. 2 and 4 to 8 show a second embodiment of the present invention, in which a surge voltage absorbing element is arranged on a brush holding member. In addition, the same code | symbol is attached | subjected to the same equivalent part as 1st embodiment, and description is abbreviate | omitted.

FIGS. 5 and 6 show the brushes 22 and 23 and the brush holding member 24. FIG. 5 is a front view seen from the left side of FIG. 4, and FIG. 6 is a rear view seen from the right side of FIG. It is. The brush holding member 24 is formed of an electrical insulating material such as a resin, and has a ring-shaped bottom surface 24h. As shown in FIG. 5, two brush storage recesses 24a and 24b having an arc-shaped cross section are formed at symmetrical positions approximately 180 ° apart in the circumferential direction of the brush holding member 24. As shown in FIG. 4, the brush receiving recesses 24a and 24b are formed in a shape having an axial dimension (depth) covering substantially the entire axial dimension of the brush holding member 24.

The brushes 22 and 23 are formed in an arcuate cross section along the brush accommodating recesses 24a and 24b, and the positive brush 22 is slidably accommodated in one of the brush accommodating recesses 24a in the axial direction. A coil spring 25 is disposed as an elastic pressing member between one end of the side brush 22 and the bottom of the brush housing recess 24a. Therefore, the other end of the positive brush 22 is always pressed against the positive slip ring 19 by the spring force of the coil spring 25.

The brush 23 on the negative electrode side is slidably received in the other brush receiving recess 24b in the axial direction, and elastically moves between one end of the brush 23 on the negative electrode side and the bottom surface of the brush receiving recess 24b. A coil spring 26 is arranged as a pressing member. Therefore, the other end of the brush 23 on the negative electrode side is always pressed against the slip ring 20 on the negative electrode side by the spring force of the coil spring 26.

In the brush holding member 24, two projections 24f and 24g extending in the axial direction are formed on the outer peripheral surface of the brush storage recesses 24a and 24b at symmetrical positions 180 ° apart. On the other hand, two recesses 6b and 6c into which the two projections 24f and 24g are fitted are formed on the inner peripheral surface of the boss 6a. Therefore, the two projections 24f, 24g and the two recesses 6b, 6c
, The brush holding member 24 is connected to the boss portion 6a.
Are positioned and held in the rotational direction on the inner peripheral surface.

The positive brush 22 and the negative brush 23
Are electrically connected to one ends of lead wires (pigtails) 27 and 28 on the positive electrode side and the negative electrode side, respectively. The other ends of the lead wires 27 and 28 are connected to a brush housing recess 24a,
The brush holder 24 passes through the holes 24c and 24d (see FIG. 6) on the bottom surface of the brush 24b and is taken out of the brush holding member 24 on the compressor 5 side (the surface in FIG. 6).

A terminal piece 29 on the positive electrode side and a terminal piece 30 on the negative electrode side are integrally formed on the bottom surface 24h of the brush holding member 24 by insert molding. These two terminal pieces 29, 30
Are made of a conductive metal such as copper or aluminum, and are provided on both sides of the bottom surface 24h (that is, the brush 2 shown in FIG. 5).
2, 23 and the compressor 5 side shown in FIG. 6).

As shown in FIG. 5, the two terminal strips 29 and 30 are relatively close to each other in the middle of the location where the brushes 22 and 23 are arranged. A gap G is provided for electrical insulation. In the terminal piece 29 on the positive electrode side, the other end of the lead wire 27 from the positive electrode side brush 22 is mechanically and electrically coupled to the bent portion 29a formed on the compressor 5 side by caulking and soldering. Have been.

Similarly, in the terminal piece 30 on the negative electrode side, the other end of the lead wire 28 from the negative brush 23 is crimped to the bent portion 30a formed on the surface on the compressor 5 side by crimping and soldering. And electrically coupled. Further, a second bent portion 29b (FIG. 5) is formed on a surface of the terminal piece 29 on the positive electrode side on the brush 22 or 23 side,
An end of an external circuit connection lead wire 31 is mechanically and electrically connected to the bent portion 29b by caulking and soldering. The lead wire 31 is connected to the brush holding member 24.
Through the hole portion 24e of the bottom surface portion 24h, and is taken out to the surface on the compressor 5 side. The lead wire 31 is wired on the outer surface of the front housing 6 of the compressor 5 and is connected to an external control circuit shown in FIG.

The bottom 24h of the brush holding member 24
On the surface of the compressor 5 side, a bent portion 30b having a flat surface is formed in the terminal piece 30 on the negative electrode side.
Is pressed against the outer surface of the front housing 6 so that the terminal piece 30 on the negative electrode side is directly grounded to the vehicle body via the front housing 6 made of metal (aluminum).

The bottom 24h of the brush holding member 24
A diode 32 as a surge voltage absorbing element is arranged on the surface of the compressor 5 side. Due to the arrangement of the diode 32, a concave portion 33 is formed in the bottom portion 24h of the brush holding member 24 at an intermediate portion between the bent portions 29a and 30a of the two terminal pieces 29 and 30. The concave portion 33 is formed so as to accommodate the cylindrical shape of the diode 32, and the width of the concave portion 33 is designed to be slightly smaller than the outer diameter of the diode 32 so that the diode 32 is formed as shown in FIG. It can be held in the recess 33 by press fitting.

The lead wires 32a and 32b at both ends of the diode 32 are mechanically and electrically coupled simultaneously with the lead wires 27 and 28 at the bent portions 29a and 30a. In addition, the bending part 29a in the brush holding member 24,
The surfaces of the joints 29b and 30a are also electrically insulated by applying an electric insulating material (insulating varnish or the like). The diode 32 is connected in parallel in the opposite direction to the positive and negative polarities of the electromagnetic coil 2 as shown in the connection diagram of FIG.
Of the diode 32, the positive lead 32a of the diode 32 is connected to the bent portion 30a of the negative terminal strip 30, and the negative lead 32b of the diode 32 is connected to the positive electrode. Connected to the bent portion 29a of the terminal piece 29 on the side.

In FIG. 8, the positive lead wire 31 is shown.
Is connected to a vehicle-mounted power supply battery 36 via a relay contact 35 that is opened and closed by a control circuit 34 of the vehicle air conditioner. Also in the second embodiment, the negative electrode side brush 2
The ground brush 3 is grounded by connecting the negative brush 23 to the front housing 6 without drawing out the wiring to the outside. Therefore, the configuration of a connector or the like for drawing out the lead wire 28 of the negative brush 23 to the outside becomes unnecessary, and the configuration is simplified. (Other Embodiments) The shapes of the brushes 22 and 23 are not limited to the arc-shaped cross-sections shown in FIGS. 3 and 5 and can be deformed into various shapes. The positions of the brushes 22 and 23 are also 180 in the circumferential direction. ° It is not limited to a symmetrical position and can be set freely.

In each of the above embodiments, the present invention is applied to a coil rotation type electromagnetic clutch in which the electromagnetic coil 2 is disposed on a driving rotor (driving rotating member) 1 integrated with the pulley portion 1a. However, as another type of coil rotation type electromagnetic clutch, the electromagnetic coil 2 is arranged on a hub (driven side rotating member) 11 connected to a rotating shaft 13 of a compressor (rotating machine) 5 and an armature 8 is provided. To the drive-side rotor 1 via a leaf spring (elastic connecting member) 9,
Armature 8 is turned into hub 11 by electromagnetic attraction of electromagnetic coil 2
There is also known a type in which the rotation of the drive-side rotor 1 is transmitted to the rotating shaft 13 via the armature 8 and the hub 11 by being attracted to the rotor, and the present invention can be applied to such a type of electromagnetic clutch. .

In each of the above embodiments, the electromagnetic coil 2
Needless to say, the positions of the members on the positive (+) side and the negative (-) side illustrated in the illustrated current path may be switched between the positive and negative sides. The specific configuration of the energization path to the electromagnetic coil 2 is not limited to the illustrated one, and it is needless to say that various modifications can be made according to the specifications of the electromagnetic clutch.

Terminal piece 1 of slip ring holding member 18
In the above-described embodiment, a combination of caulking and soldering is used as means for the lead wire connecting portions at 9a and 20a and the lead wire connecting portions at the terminal pieces 29 and 30 of the brush holding member 24. Alternatively, only soldering may be used. Also, instead of soldering,
Means such as fusing (welding) can also be used as the means for connecting the lead wires.

In the first embodiment, the negative-electrode-side brush 23 is pressed against the inner diameter side of the boss 6a by using the leaf spring 45. However, the pressing of the brush by the leaf spring 45 is not essential. In the first embodiment, the width in the circumferential direction of the storage recess 24b and the negative brush 23 is formed in a tapered shape such that the width decreases from the inner diameter side to the outer diameter side. However, this shape does not need to be a strictly taper shape, and
Any shape may be used as long as the shape allows the negative brush 23 to be stably held without falling out of b.

Coil springs 25 and 26, leaf spring 4
5 can be replaced by another spring means for pressing the brushes 22,23.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electromagnetic clutch showing a first embodiment of the present invention.

FIG. 2 is a front view of the slip ring holding member of FIG.

FIG. 3 is a front view of a brush holding member and a boss of FIG. 1;

FIG. 4 is a longitudinal sectional view of an electromagnetic clutch showing a second embodiment of the present invention.

FIG. 5 is a front view of a brush holding member and a boss of FIG. 4;

FIG. 6 is a rear view of the brush holding member of FIG. 4;

FIG. 7 is an enlarged sectional view of a diode arrangement portion of FIG.

FIG. 8 is an electrical connection diagram of an electromagnetic clutch according to a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor (drive side rotating member) 2: Electromagnetic coil, 5 ...
Compressor (rotary machine), 6: Front housing (fixed member), 6a: Boss (fixed member), 8: Armature, 9
... leaf spring (elastic connecting member), 11 ... hub (driven side rotating member), 13 ... rotating shaft, 16, 17, 27 ... lead wire, 1
8: Slip ring holding member, 19, 20: Slip ring, 19a, 20a, 29: Terminal piece, 22, 23: Brush, 24: Brush holding member, 45: Leaf spring (elastic pressing member).

Claims (6)

[Claims] An electromagnetic clutch for intermittently transmitting rotation to a rotating shaft (13) of a rotating machine (5), comprising: a rotating member (1); An electromagnetic coil (2) that generates an electromagnetic attractive force when energized; and an electromagnetic coil (2) that is disposed to face the rotating member (1) and that is generated by the electromagnetic coil (2).
And an armature (8) that is attracted to the rotating member (1). When the armature (8) is attracted to the rotating member (1), a rotating drive source passes through the rotating member (1) and the armature (8). The rotation is transmitted to the rotating shaft (13), and the brushes (22, 2) which are pressed against the slip rings (19, 20) and slide on the slip rings (19, 20).
3) is provided, and the electromagnetic coil (2) is energized through the sliding energizing mechanism. The slip rings (19, 20) are connected to each other through a slip ring holding member (18). The brushes (22, 23) are held by a rotating member (1) and the brush holding members (2)
4) through the fixing member (6, 6a), and one of the brushes (22, 23) is connected to the fixing member (6, 6a) and grounded. An electromagnetic clutch. 2. The electromagnetic clutch according to claim 1, wherein the one brush (22, 23) is in direct contact with the fixing member (6, 6a) and is grounded. 3. The one brush (22, 23) is pressed against the fixing member (6, 6a) by an elastic pressing member (45) and is in direct contact with the fixing member (6, 6a).
The electromagnetic clutch according to 1. 4. The fixing member has a boss portion (6a) that projects cylindrically outward from a housing (6) of the rotating machine (5) in the axial direction, and the rotating shaft (13) includes the boss. The brush holding member (24) is disposed at the center of the portion (6a), and the brush holding member (24) is formed in a space (2) formed between the inner diameter side of the boss portion (6a) and the rotating shaft (13).
The brush holding member (24) is provided with a storage part (24b) for storing the one brush (23), and the storage part (24b) is open to the outside diameter side. (24c), wherein the one brush (23) is in contact with the inner diameter side (6c) of the boss part (6a) at the opening (24c) of the storage part (24b). The electromagnetic clutch according to claim 2 or 3, wherein: 5. The circumferential width of the storage portion (24b) is:
The brush holding member (24) is formed in a tapered shape so as to become smaller from the inner diameter side to the outer diameter side, and the one brush (23) has a shape corresponding to the shape of the storage portion (24b). The storage portion (24b)
The electromagnetic clutch according to claim 4, wherein the electromagnetic clutch is housed inside. 6. The electromagnetic device according to claim 1, wherein the one brush is connected to the fixing member via a lead wire and is grounded. clutch.