JP2011158003A - Electromagnetic clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply a limiter broken by axial force, to an electromagnetic clutch and to prevent falling-off of driven side rotation bodies. <P>SOLUTION: The electromagnetic clutch includes a drive side rotation body 21 rotated by rotational driving force output from a drive source; the driven side rotation bodies 30, 33 connected to the drive side rotation body 21 so as to be rotated together with a rotating shaft 11 of a drive object device 10; an electromagnet 22 generating electromagnetic force for connecting the driven side rotation bodies to the drive side rotation body 21; the limiter 37 serving as a member for connecting the driven side rotation bodies to the rotating shaft 11 and broken by axial force when torque transmitted to the driven side rotation bodies from the drive side rotation body becomes predetermined torque or more, to separate the driven side rotation bodies from the rotating shaft 11; and a stopper 39 formed projecting radially outward from the rotating shaft 11 to abut on the driven side rotation bodies separated from the rotating shaft 11 by the breakage of the limiter 37, in the axial direction of the rotating shaft 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetic clutch that transmits and shuts off rotational power.

  2. Description of the Related Art Conventionally, a compressor of a vehicle air conditioner obtains a driving force from a traveling engine via a belt (V-belt), and its operation control is generally performed by turning on and off an electromagnetic clutch.

  The electromagnetic clutch connects a pulley (drive-side rotating body) that rotates by a rotational driving force output from a traveling engine, an armature that rotates by being connected to the pulley, and a pulley and an armature that are energized. And an electromagnet that generates electromagnetic force.

  The armature is connected to the rotating shaft of the compressor via a hub. When the armature is attracted by the electromagnetic force of the electromagnet and connected to the pulley, the rotating shaft of the compressor is rotated to operate the compressor.

  In such a configuration, when the compressor is seized for some reason and the compressor is locked (movable parts in the compressor are seized and fixed), the electromagnetic clutch is turned off to protect the belt and the driving force is reduced. It is necessary to cut off the transmission.

  Therefore, in the prior art described in Patent Document 1, a thermal fuse is connected in series to an electric circuit in the electromagnetic clutch. According to this, when the compressor is locked, the thermal fuse is blown by the frictional heat generated between the armature and the friction surface of the rotor housing, so that the current application to the electromagnetic clutch is cut off and the electromagnetic clutch is Turned off.

  On the other hand, Patent Document 2 describes a limiter mechanism that interrupts transmission of driving force when a compressor is locked in a compressor that does not have an electromagnetic clutch. In this prior art, a hub that is always connected to a pulley is connected to a rotating shaft of a compressor via a limiter. When the compressor is locked and an excessive load is applied, the limiter is broken by the axial force. As a result, the hub is disconnected from the rotating shaft, and the transmission of the driving force is interrupted.

JP 2000-27895 A JP 2004-340158 A

  However, the conventional technique of Patent Document 1 has a problem that the belt slips and breaks when the belt sliding torque is lower than the transmission torque because the transmission torque varies greatly on the friction surface.

  Therefore, the present inventor has studied to apply the limiter mechanism of Patent Document 2 to the electromagnetic clutch. However, the electromagnetic clutch has a structure in which the armature is separated from the pulley when the clutch is turned off. In other words, in the compressor having no electromagnetic clutch of Patent Document 2, the hub is always connected to the pulley, whereas in the electromagnetic clutch, the armature and the hub are not always connected to the pulley.

  For this reason, when the limiter mechanism of Patent Document 2 is applied to the electromagnetic clutch, there is a problem that when the limiter breaks, the hub and the armature (the driven-side rotating body) separated from the rotating shaft fall off.

  In view of the above points, an object of the present invention is to apply a limiter that is broken by an axial force to an electromagnetic clutch and to prevent the driven-side rotating body from falling off.

In order to achieve the above object, according to the first aspect of the present invention, a driving side rotating body (21) that rotates by a rotational driving force output from a driving source;
A driven rotary body (30, 33) that rotates together with the rotary shaft (11) of the drive target device (10) by being connected to the drive rotary body (21);
An electromagnet (22) for generating an electromagnetic force for coupling the driven side rotator (30, 33) to the drive side rotator (21);
A member for connecting the driven-side rotator (30, 33) and the rotating shaft (11), and the torque transmitted from the drive-side rotator (21) to the driven-side rotator (30, 33) is a predetermined torque or more. A limiter (37) that breaks due to an axial force and separates the driven-side rotating body (30, 33) from the rotating shaft (11).
In the axial direction of the driven-side rotator (30, 33) and the rotating shaft (11) which are formed to protrude radially outward from the rotating shaft (11) and are separated from the rotating shaft (11) by the breakage of the limiter (37). It is provided with the stopper (39) to contact | abut.

  According to this, when the torque transmitted from the drive-side rotator (21) to the driven-side rotator (30, 33) exceeds a predetermined torque, the limiter (37) is broken by the axial force and the driven-side rotator. Since (30, 33) is separated from the rotating shaft (11), transmission of the driving force can be cut off.

  Further, the driven-side rotator (30, 33) separated from the rotating shaft (11) by the breakage of the limiter (37) rotates with the stopper (39) formed to protrude radially outward from the rotating shaft (11). Since it abuts in the axial direction of the shaft (11), it is possible to prevent the driven-side rotator (30, 33) from falling off.

  Therefore, it is possible to apply the limiter that is broken by the axial force to the electromagnetic clutch and to prevent the driven-side rotating body from falling off.

  According to a second aspect of the present invention, in the power transmission device according to the first aspect, the driven side rotating body (30, 33) separated from the rotating shaft (11) by the breakage of the limiter (37) is replaced with the driving side rotating body. It is characterized by comprising a separating means (34) for separating from (21).

  According to this, since the space | interval (air gap) between a driven side rotary body (30, 33) and a drive side rotary body (21) becomes large compared with the state before a fracture | rupture of a limiter (37), an electromagnet (22) Even if it is in an energized state, it can suppress that the driven side rotary body (30, 33) is reconnected to the drive side rotary body (21).

According to a third aspect of the present invention, in the power transmission device according to the second aspect, the driven-side rotator (30, 33) is attracted to the drive-side rotator (21) by the electromagnetic force. And an inner hub (33) for transmitting torque from the armature (30) to the rotating shaft (11),
The inner hub (33) includes a first inner hub (331) connected to the armature (30) and a second inner hub (332) to which torque from the first inner hub (331) is transmitted by frictional force. Divided and formed,
The separating means (34) is a spring arranged between the first inner hub (331) and the second inner hub (332).

  According to this, when the limiter (37) is broken, the first inner hub (331) and the armature (30) are separated from the drive side rotating body (21) by the spring (34), so that the armature (30) is re-sucked. Can be suppressed. For this reason, it can suppress reliably that a driven side rotary body (30, 33) is reconnected with a drive side rotary body (21).

According to a fourth aspect of the present invention, in the power transmission device according to the third aspect, the second inner hub (332) has the rotating shaft (11) inserted therein and the first inner hub (331) and the rotating shaft. (11) has a cylindrical portion (332b) in contact with the axial direction,
The spring (34) is arranged between the cylindrical portion (332b) and the first inner hub (331). Thereby, a spring (34) can be arrange | positioned with a simple structure.

According to a fifth aspect of the present invention, in the power transmission device according to the second aspect, the driven-side rotator (30, 33) is attracted to the drive-side rotator (21) by the electromagnetic force. And an inner hub (33) for transmitting torque from the armature (30) to the rotating shaft (11),
The inner hub (33) is connected to the cylindrical portion (33a) into which the rotating shaft (11) is inserted and to connect the cylindrical portion (33a) and the armature (30) extending radially outward from the cylindrical portion (33a). Part (33b),
The spring (34) is arranged outside the cylindrical portion (33b).

  According to this, when the limiter (37) is broken, the inner hub (33) and the armature (30) are separated from the drive side rotating body (21) by the spring (34), so that re-suction of the armature (30) can be suppressed. .

  Further, since the inner hub (33) can be formed integrally, the spring (34) can be arranged with a simple structure.

According to a sixth aspect of the present invention, in the power transmission device according to the first aspect of the present invention, the power transmission device includes a spring (40) that biases the driven-side rotator to the side opposite to the stopper (39),
The limiter (37)
A hub connecting portion (37a) connected to the driven side rotating body (30, 33);
A rotating shaft connecting portion (37b) connected to the rotating shaft (11);
The hub connecting portion (37a) and the rotating shaft connecting portion (37b) are connected in the axial direction of the rotating shaft (11), and the torque transmitted from the driving side rotating body to the driven side rotating body is equal to or greater than a predetermined torque. A break portion (37c) that sometimes breaks due to axial force and separates the hub connection portion (37a) from the rotation shaft connection portion (37b),
The spring (40) is disposed between the driven side rotator (30, 33) and the hub connecting portion (37a),
The stopper (39) is formed so as to contact the hub connecting portion (37a) separated from the rotating shaft connecting portion (37b) by the breaking of the breaking portion (37c) and the axial direction of the rotating shaft (11). It is characterized by.

  According to this, when the breaking part (37c) of the limiter (37) is broken, the driven side rotating body (30, 33) is pressed against the stopper (39) by the spring (40), so that the driven side rotating body ( 30 and 33) can be stabilized. For this reason, it can prevent that a driven side rotary body (30, 33) collides with a drive side rotary body (21) locally, generate | occur | produces abnormal noise, or adheres to a drive side rotary body (21). .

  According to a seventh aspect of the present invention, in the power transmission device according to the third aspect, the power transmission device is disposed between the first inner hub (331) and the second inner hub (332), and the first inner hub (331) A slide mechanism (41) for guiding the slide movement in the axial direction is provided.

  According to this, after the limiter (37) is broken, the posture of the first inner hub (331) and the armature (30) separated from the rotating shaft (11) can be stabilized by the slide mechanism (41). Further, it is possible to more reliably prevent the armature (30) from colliding with the drive side rotator (21) locally and generating abnormal noise or adhering to the drive side rotator (21).

  In addition, torque transmission from the first inner hub (331) to the second inner hub (332) can be performed by the slide mechanism (41), so that torque transmission efficiency can be improved.

  According to an eighth aspect of the present invention, in the power transmission device according to any one of the first to seventh aspects, the labyrinth mechanism (42) is formed by the stopper (39) and the limiter (37). Features.

  According to this, the labyrinth mechanism (42) formed by the stopper (39) and the limiter (37) prevents foreign matter and water from entering the connecting portion between the limiter (37) and the rotating shaft (11). be able to. For this reason, a dedicated component (for example, a rubber cap) for preventing entry of foreign matter or water is unnecessary, and the number of components can be reduced.

According to a ninth aspect of the present invention, in the power transmission device according to the first aspect, the driven-side rotator (30, 33) is attracted to the drive-side rotator (21) by the electromagnetic force. And an inner hub (33) for transmitting torque from the armature (30) to the rotating shaft (11), and a spacer (35) interposed between the inner hub (33) and the rotating shaft (11),
The inner hub (33) and the spacer (35) are integrally formed.

  According to this, since the inner hub (33) and the spacer (35) are integrally formed, the number of parts can be reduced.

In the invention according to claim 10, in the power transmission device according to claim 1, a spring (43) for urging the driven-side rotating body (30, 33) to the opposite side to the stopper (39) is provided.
The limiter (37)
A hub connecting portion (37a) connected to the driven side rotating body (30, 33);
A rotating shaft connecting portion (37b) connected to the rotating shaft (11);
The hub connecting part (37a) and the rotating shaft connecting part (37b) are connected in the axial direction of the rotating shaft (11) and transmitted from the driving side rotating body (21) to the driven side rotating body (30, 33). A breaking portion (37c) for breaking the hub coupling portion (37a) from the rotating shaft coupling portion (37b) by breaking by an axial force when the torque exceeds a predetermined torque;
The spring (43) is characterized in that it is disposed between the rotating shaft connecting portion (37b) and the stopper (39).

  According to this, when the breaking part (37c) of the limiter (37) is broken, the driven side rotating body (30, 33) is pressed against the stopper (39) by the spring (43), so that the driven side rotating body ( 30 and 33) can be stabilized. For this reason, it can prevent that a driven side rotary body (30, 33) collides with a drive side rotary body (21) locally, generate | occur | produces abnormal noise, or adheres to a drive side rotary body (21). .

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a front view of the power transmission device in 1st Embodiment of this invention. It is an AA expanded sectional view of FIG. In FIG. 2, it is sectional drawing which shows the state which the fracture | rupture part of the limiter fractured. It is sectional drawing of the power transmission device in 2nd Embodiment of this invention. It is sectional drawing of the power transmission device in 3rd Embodiment of this invention. It is sectional drawing of the power transmission device in 4th Embodiment of this invention. It is the front view and sectional drawing of the power transmission device in 5th Embodiment of this invention. It is sectional drawing of the power transmission device in 6th Embodiment of this invention. It is sectional drawing of the power transmission device in 7th Embodiment of this invention. It is sectional drawing of the power transmission device in 8th Embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of a power transmission device 20 in the present embodiment, and FIG. 2 is an AA enlarged sectional view (axial sectional view) of FIG.

  The power transmission device 20 is applied in order to intermittently transmit the rotational driving force output from the vehicle traveling engine (drive source) to the compressor 10 that is a drive target device. The compressor 10 constitutes a refrigeration cycle apparatus for a vehicle air conditioner.

  As the compressor 10, for example, a swash plate type variable capacity compressor can be adopted. Like other types of variable displacement compressors, fixed displacement compressors such as scroll type and vane type, the refrigerant of the refrigeration cycle device is sucked by compressing and discharging by transmitting the rotational driving force. As long as it is a thing, you may employ | adopt any form as the compressor 10. FIG.

  The power transmission device 20 includes a pulley 21, an electromagnet 22, an armature 30, and the like. The pulley 21 constitutes a driving side rotating body that rotates by a rotational driving force from the engine. The armature 30 constitutes a driven side rotating body that rotates by being connected to the pulley 21. The electromagnet 22 generates an electromagnetic force that connects the pulley 21 and the armature 30 when energized.

  The electromagnet 22 includes a stator 22a and a coil 22b. The stator 22 a is formed in a ring shape with a magnetic material (specifically, iron) and is disposed coaxially with the rotating shaft 11 of the compressor 10.

  The coil 22b accommodated in the stator 22a is fixed to the stator 22a in a state of being molded with an insulating resin material (specifically, epoxy), and is electrically insulated from the stator 22a. Yes.

  Switching between energization and non-energization of the electromagnet 22 is performed by a control voltage output from an air conditioning control device (not shown).

  The pulley 21 has an outer cylindrical portion 21a, an inner cylindrical portion 21b, and an end surface portion 21c, and the cross-sectional shape in the axial direction of the rotating shaft 11 (hereinafter referred to as the rotating shaft direction) is a U-shape. The electromagnet 22 is accommodated in the internal space of the pulley 21.

  The cylindrical outer cylindrical portion 21 a is disposed coaxially with the rotation shaft 11 of the compressor 10. The cylindrical inner cylindrical portion 21 b is disposed on the inner peripheral side of the outer cylindrical portion 21 a and is disposed coaxially with the rotation shaft 11.

  The end surface portion 21c spreads in a direction (vertical direction in FIG. 2) orthogonal to the rotational axis direction so as to connect one end side portions of the outer cylindrical portion 21a and the inner cylindrical portion 21b in the rotational axis direction (left and right direction in FIG. 2). It has a different shape. A circular through-hole penetrating the front and back surfaces is formed at the center of the end surface portion 21c.

  The outer cylindrical portion 21a, the inner cylindrical portion 21b, and the end surface portion 21c are integrally formed of a magnetic material (specifically, iron), and constitute a magnetic circuit of electromagnetic force generated by the electromagnet 22. On the outer peripheral side of the outer cylindrical portion 21a, a V groove (specifically, a poly V groove) on which a V belt (not shown) is hung is formed. The V belt transmits the rotational driving force output from the engine to the pulley 21.

  The outer peripheral side of the ball bearing 24 is fixed to the inner peripheral side of the inner cylindrical portion 21b, and the cylindrical that protrudes from the housing forming the outer shell of the compressor 10 to the power transmission device 20 side on the inner peripheral side of the ball bearing 24. A boss 12 is fixed. Thereby, the pulley 21 is fixed to the housing of the compressor 10 so as to be freely rotatable.

  The outer surface of the end surface portion 21 c forms a friction surface that comes into contact with the armature 30 when the pulley 21 and the armature 30 are connected. A friction member (not shown) for increasing the coefficient of friction of the end surface portion 21c is disposed on a part of the surface of the end surface portion 21c. The friction member is made of a nonmagnetic material. Specifically, a material obtained by solidifying alumina with a resin or a sintered material of metal powder (specifically, aluminum powder) can be employed as the friction member.

  The armature 30 is an annular plate member that extends in a direction orthogonal to the rotation axis direction, and has a through-hole formed at the center thereof. The armature 30 is formed of a magnetic material (specifically, iron), and constitutes a magnetic circuit of electromagnetic force generated by the electromagnet 22 together with the pulley 21.

  A flat portion facing the end surface portion 21 c of the pulley 21 is formed on one end side (right end side in FIG. 2) of the armature 30 in the rotation axis direction. This flat surface portion constitutes a friction surface that comes into contact with the pulley 21 when the pulley 21 and the armature 30 are connected.

  A flat portion is also formed on the other end side (left end side in FIG. 2) of the armature 30 in the rotation axis direction, and an outer hub 31 is fixed to the flat portion by a rivet or the like. The outer hub 31 extends in the radial direction (a direction orthogonal to the rotational axis direction) from the cylindrical portion extending in the rotational axis direction and the end portion (right end portion in FIG. 2) on the armature 30 side of the cylindrical portion. And an annular plate portion fixed to.

  On the inner peripheral surface of the cylindrical portion of the outer hub 31, an annular elastic member 32 is fitted and bonded. An inner hub 33 is fitted and bonded to the inner peripheral surface of the elastic member 32.

  The elastic member 32 is made of chlorinated butyl rubber (Cl-IIR) and is vulcanized and bonded to the outer hub 31 and the inner hub 33. The elastic member 32 applies an elastic force to the outer hub 31 in a direction away from the pulley 21.

  When the electromagnet 22 is in a non-energized state and no electromagnetic force is generated, a gap is formed between the flat portion on one end side of the armature 30 and the outer surface of the end surface portion 21c of the pulley 21 by the elastic force of the elastic member 32. Can be generated.

  The inner hub 33 is divided into a first inner hub 331 on the elastic member 32 side and a second inner hub 332 on the rotating shaft 11 side. The first inner hub 331 extends in the rotational axis direction and is bonded to the elastic member 32, and extends radially inward from an end portion (right end portion in FIG. 2) on the armature 30 side of the cylindrical portion 331a. And an annular plate portion 331b.

  The second inner hub 332 includes an annular plate portion 332a facing the annular plate portion 331b of the first inner hub 331, and an inner peripheral edge portion of the annular plate portion 332a toward the compressor 10 side (right side in FIG. 2). And a cylindrical portion 332b into which the rotating shaft 11 is inserted.

  The second inner hub 332 is disposed on the compressor 10 side (the right side in FIG. 2) with respect to the first inner hub 331. The first inner hub 331 and the second inner hub 332 are only in contact with each other at the annular plate portions 331b and 332a, and are not fixed. In other words, the two annular plate portions 331b and 332a constitute friction surfaces in contact with each other. Therefore, the torque from the first inner hub 331 is transmitted to the second inner hub 332 by a frictional force.

  A groove portion 332c for arranging the spring 34 is formed in the annular plate portion 332a of the second inner hub 332. The spring 34 generates a biasing force in a direction that separates the first and second inner hubs 331 and 332. In the example of FIG. 2, the spring 34 is formed in a plate shape.

  A cylindrical spacer 35 is fixed to the end portion on the compressor 10 side (the right end portion in FIG. 2) of the cylindrical portion 332b of the second inner hub 332. The spacer 35 is fixed to the cylindrical portion 332b of the second inner hub 332 by press-fitting and caulking.

  The spacer 35 is formed of an iron-based metal material, and the inner peripheral side of the spacer 35 is only in contact with the rotating shaft 11 of the compressor 10 and is not fixed. The end surface of the spacer 35 on the compressor 10 side is in contact with a stepped portion 11 a formed on the rotating shaft 11 via an annular plate-like shim 36.

  The shim 36 plays a role of adjusting the position of the spacer 35 in the direction of the rotation axis, and hence the position of the armature 30 in the direction of the rotation axis. More specifically, when the electromagnet 22 is not energized, an appropriate gap is formed between the armature 30 and the end surface portion 21c of the pulley 21, and when the electromagnet 22 is energized, the electromagnet 22 is The thickness of the shim 36 is set so that the generated electromagnetic force exceeds the elastic force of the elastic member 32 and the pulley 21 and the armature 30 are connected.

  That is, when the electromagnet 22 is energized, the electromagnetic force generated by the electromagnet 22 exceeds the elastic force of the elastic member 32 to form an appropriate air gap (magnetic resistance) that connects the pulley 21 and the armature 30. The thickness of the shim 36 is set so that it can be done.

  Further, the shim 36 is made of a hardened alloy steel such as SK5 by quenching and tempering. And the thing whose hardness is higher than the hardness of the rotating shaft 11 is employ | adopted. In addition, it is desirable that the spacer 35 has a hardness higher than that of the limiter 37.

  The limiter 37 is a member that connects the first inner hub 331 and the rotary shaft 11 and is formed of iron. The limiter 37 is formed in a cylindrical shape extending in the rotation axis direction, and is inserted into the center holes of the first and second inner hubs 331 and 332.

  A portion of the cylindrical limiter 37 opposite to the compressor 10 (the left portion in FIG. 2) constitutes a hub connecting portion 37 a fixed to the inner peripheral portion of the first inner hub 331. A part of the hub connecting portion 37a faces the inner peripheral portion of the first inner hub 331 in the axial direction. The hub connecting portion 37a and the first inner hub 331 are fixed by caulking.

  A portion of the limiter 37 on the compressor 10 side (right side in FIG. 2) constitutes a rotating shaft connecting portion 37 b connected to the rotating shaft 11 of the compressor 10. In this example, a female screw portion is formed on the rotary shaft connecting portion 37b, a male screw portion is formed on the rotary shaft 11 of the compressor 10, and the rotary shaft connecting portion 37b is screwed to the rotary shaft 11. Yes.

  Grease is applied to the female screw portion of the rotary shaft connecting portion 37b. The grease plays a role of reducing the fluctuation of the friction coefficient between the female screw portion of the rotary shaft connecting portion 37 b and the male screw portion of the rotary shaft 11. Intrusion of foreign matter and water into the grease is prevented by a rubber cap 38 fitted in the center hole of the hub connecting portion 37a.

  The rotation shaft connecting portion 37b is inserted into the center hole of the cylindrical portion 332b of the second inner hub 332. A predetermined gap is provided between the outer peripheral surface of the rotating shaft connecting portion 37 b and the inner peripheral surface of the cylindrical portion 332 b of the second inner hub 332, and the outer peripheral surface of the rotating shaft connecting portion 37 b is the second inner hub 332. The cylindrical portion 332b is not in contact with the inner peripheral surface.

  The breaking portion 37c connects the hub connecting portion 37a and the rotating shaft connecting portion 37b in the direction of the rotating shaft, and plays a role of breaking when the transmission torque exceeds a predetermined torque and blocking torque transmission. Specifically, the fracture portion 37 c forms a thin portion in the limiter 37. That is, the outer diameter of the fractured portion 37c is smaller than the outer diameter of the hub connecting portion 37a and the outer diameter of the rotating shaft connecting portion 37b.

  As can be understood from the above description, the inner hub 33 (first and second inner hubs 331 and 332), the spacer 35, and the shim 36 are disposed between the hub connecting portion 37 a of the limiter 37 and the stepped portion 11 a of the rotating shaft 11. Is sandwiched. Thereby, the position of the hub connecting portion 37a in the rotation axis direction is defined.

  When the pulley 21 and the armature 30 are connected, the driven rotary body and the limiter 37 including the armature 30, the outer hub 31, the elastic member 32, the inner hub 33, the spacer 35, and the shim 36 rotate together with the pulley 21.

  A stopper 39 is fixed to an end portion (left end portion in FIG. 2) on the opposite side of the rotary shaft 11 from the compressor 10. The stopper 39 is a metal plate having a C-shaped planar shape (see FIG. 1), and is fitted into a groove (see FIG. 2) formed on the rotary shaft 11 by utilizing its elastic deformation.

  Next, the operation of this embodiment in the above configuration will be described. When the air conditioning control device does not output a control voltage and the electromagnet 22 is in a non-energized state, the electromagnet 22 does not generate an electromagnetic force, so that the pulley 21 and the armature 30 are caused by the elastic force of the elastic member 32. Disconnected. Therefore, the rotational driving force of the engine is not transmitted to the compressor 10. As a result, the refrigeration cycle device does not operate.

  When the air conditioning control device outputs a control voltage to energize the electromagnet 22, the electromagnetic force generated by the electromagnet 22 exceeds the elastic force of the elastic member 32, and the pulley 21 and the armature 30 are connected. Thereby, the rotational driving force is transmitted from the pulley 21 constituting the driving side rotating body to the armature 30, and the driven side rotating body including the armature 30, the outer hub 31, the elastic member 32, the inner hub 33, the spacer 35, and the shim 36. The limiter 37 rotates.

  At this time, if the compressor 10 is not locked, the rotating shaft 11 of the compressor 10 is rotated by the frictional force generated between the shim 36 of the driven side rotating body and the step portion 11a of the rotating shaft 11 of the compressor 10. To do. That is, since the rotational driving force output from the engine is transmitted to the compressor 10, the refrigeration cycle apparatus operates.

  On the other hand, when the compressor 10 is locked and the rotary shaft 11 cannot rotate, the limiter 37 is rotated so that the female screw portion of the rotary shaft connecting portion 37b of the limiter 37 is changed to the male screw portion of the rotary shaft 11. Axial force is generated by tightening.

  At this time, the position of the limiter 37 in the rotation axis direction of the hub connecting portion 37 a is regulated by the inner hub 33, the spacer 35, the shim 36, and the stepped portion 11 a of the rotation shaft 11. For this reason, tensile stress is applied to the fractured portion 37c that connects the hub connecting portion 37a and the rotating shaft connecting portion 37b. When the tensile stress applied to the breakage portion 37c becomes equal to or greater than a predetermined value, the breakage portion 37c breaks and the hub connection portion 37a is separated from the rotation shaft connection portion 37b as shown in FIG.

  Here, the driven-side rotating body and the limiter 37 are connected only to the rotating shaft connecting portion 37 b of the limiter 37 as a connecting portion with the rotating shaft 11. For this reason, when the breaking portion 37c breaks, the frictional force generated between the shim 36 and the step portion 11a of the rotating shaft 11 of the compressor 10 is reduced, and the transmission of the rotational driving force from the engine to the compressor 10 is reduced. Blocked.

  When the fracture portion 37c is fractured, the first inner hub 331 is pulled away from the second inner hub 332 by the biasing force of the spring 34, and the hub connecting portion 37a fixed to the first inner hub 331 is pressed against the stopper 39. Abut.

  For this reason, the hub connecting portion 37a separated from the rotating shaft 11 by the breaking of the breaking portion 37c and the driven side rotating body (specifically, the first inner hub 331, the elastic member 32, the outer hub 31, and the armature 30). It can be prevented from falling off. As a result, it is possible to prevent the driven-side rotator separated from the rotating shaft 11 from dropping and damaging other devices arranged around the power transmission device 20.

  Further, since the first inner hub 331 is pulled away from the second inner hub 332 by the urging force of the spring 34, the gap (air gap) between the armature 30 and the pulley 21 is increased compared to the state before the breakage. The armature 30 is prevented from being re-sucked even if is energized.

  Further, since the hub connecting portion 37a is pressed against the stopper 39 by the urging force of the spring 34, the posture of the driven side rotating body separated from the rotating shaft 11 can be stabilized. Therefore, the armature 30 and the pulley 21 can be stabilized with a large gap (air gap). Therefore, the armature 30 locally collides with the pulley 21 to generate abnormal noise, or the pulley 21 is stiffened. It can be prevented from wearing.

(Second Embodiment)
In the second embodiment, as shown in FIG. 4, the position of the spring 34 is changed with respect to the first embodiment. Specifically, the spring 34 is disposed at the radially innermost portion of the first inner hub 331 and the second inner hub 332. In the example of FIG. 4, the spring 34 is formed in a coil shape.

  According to the present embodiment, the second inner hub 332 may be formed in a cylindrical shape, and it is not necessary to form the annular plate portion 332a in the first embodiment, so that the structure of the inner hub 33 can be simplified.

(Third embodiment)
In the first embodiment, the inner hub 33 is divided into the first inner hub 331 and the second inner hub 332, and the spring 34 is interposed between the first inner hub 331 and the second inner hub 332. Although arranged, in the third embodiment, as shown in FIG. 5, the inner hub 33 is integrally formed, and the spring 34 is arranged between the inner hub 33 and the spacer 35.

  Specifically, the inner hub 33 includes a cylindrical portion 33a in which the rotating shaft 11 is inserted, and a connecting portion 33b that extends radially outward from the inner cylindrical portion 33a and connects the cylindrical portion 33b and the armature 30. ing. The cylindrical portion 33 a is fixed to the spacer 35. The connecting portion 33b has a cylindrical outer peripheral edge, and is bonded to the elastic member 32 at the outer peripheral edge.

  The spring 34 is formed in a coil shape and is disposed on the outer peripheral side of the cylindrical portion 33 a of the inner hub 33.

  According to this embodiment, the structure of the inner hub 33 can be simplified by forming the inner hub 33 integrally.

(Fourth embodiment)
In the first embodiment, the inner hub 33 is divided into the first inner hub 331 and the second inner hub 332, and the spring 34 is interposed between the first inner hub 331 and the second inner hub 332. Although arranged, in the third embodiment, as shown in FIG. 6, the inner hub 33 is integrally formed, and the spring 40 is arranged between the inner hub 33 and the limiter 37.

  More specifically, the inner hub 33 includes an outer cylindrical portion that is bonded to the elastic member 32, an inner cylindrical portion that is fixed to the spacer 35, and an annular plate portion that connects the cylindrical portions. Yes. The spring 40 is formed in a coil shape, and is disposed between the inner cylindrical portion of the inner hub 33 and the hub connecting portion 37 a of the limiter 37.

  The inner hub 33 is not fixed to the hub connecting portion 37 a of the limiter 37, and is connected to the hub connecting portion 37 a via the spring 40.

  Therefore, the inner hub 33 is pressed against the spacer 35 side by the urging force of the spring 40 before the limiter is actuated (before the fractured portion 37 c is broken). As a result, a frictional force is generated between the shim 36 and the stepped portion 11a of the rotary shaft 11 of the compressor 10, and the rotary shaft 11 of the compressor 10 rotates.

  After the limiter is actuated (after the breaking portion 37 c is broken), the hub connecting portion 37 a of the limiter 37 is pulled away from the inner hub 33 by the biasing force of the spring 40 and comes into contact with the stopper 39. As a result, the urging force that presses the inner hub 33 toward the spacer 35 is reduced, and the frictional force generated between the shim 36 and the stepped portion 11a of the rotary shaft 11 of the compressor 10 is reduced. The transmission of the rotational driving force is cut off.

  At this time, the urging force (the urging force of the spring 40) that presses the inner hub 33 toward the spacer 35 decreases, but the inner hub 33 is pressed to the spacer 35 side to some extent by the spring 40, so that the posture of the inner hub 33 is stabilized. Can be made. For this reason, it is possible to prevent the armature 30 from colliding with the pulley 21 locally to generate abnormal noise or adhere to the pulley 21.

  Moreover, according to this embodiment, the structure of the inner hub 33 can be simplified by forming the inner hub 33 integrally.

(Fifth embodiment)
As shown in FIG. 7, the fifth embodiment is obtained by adding a slide mechanism 41 that guides the sliding movement of the first inner hub 331 in the rotation axis direction with respect to the first embodiment.

  The slide mechanism 41 includes a slide pin 41 a fixed to the second inner hub 332 and a slide hole 41 b formed in the first inner hub 331.

  The slide pin 41a protrudes from the annular plate portion 332a of the second inner hub 332 toward the annular plate portion 331b of the first inner hub 331 in the rotation axis direction, and the second inner hub 332 has an appropriate means such as screw fastening. It is fixed to the annular plate portion 332a.

  The slide hole 41b passes through the annular plate portion 331b of the first inner hub 331 in the rotation axis direction, and the slide pin 41a is inserted therein. A plurality of slide pins 41a and slide holes 41b are provided in the circumferential direction (four in the example of FIG. 7).

  According to the present embodiment, after the limiter is actuated (after the breaking portion 37c is broken), the posture of the driven-side rotating body separated from the rotating shaft 11 can be stabilized also by the slide mechanism 41. It is possible to more reliably prevent the generation of abnormal noise due to a collision with the pulley 21 locally or adhesion to the pulley 21.

  In the first embodiment, torque is transmitted by friction between the first inner hub 331 and the second inner hub 332. However, according to the present embodiment, torque is not only generated by the friction but also by the slide mechanism 41. Can be transmitted. For this reason, torque transmission efficiency can be improved.

(Sixth embodiment)
In the first embodiment, the rubber cap 38 prevents foreign matter and water from entering the grease applied to the female screw portion of the rotary shaft coupling portion 37b of the limiter 37. In the sixth embodiment, FIG. In this way, the labyrinth mechanism 42 prevents foreign matter and water from entering the grease by the labyrinth mechanism 42. 42b. The groove 42a is formed on the entire surface of the hub connecting portion 37a on the surface of the hub connecting portion 37a facing the stopper 39. The protruding piece 42 b protrudes from the outer peripheral edge portion of the stopper 39 toward the groove 42 a and is formed over the entire circumference of the stopper 39.

  According to the present embodiment, since the stopper 39 has a function of preventing the entry of foreign matter and water, the rubber cap 38 as a dedicated component for preventing the entry of foreign matter and water becomes unnecessary, and the number of parts is reduced. Can be reduced, and thus the cost can be reduced.

(Seventh embodiment)
In the seventh embodiment, as shown in FIG. 9, the second inner hub 332 and the spacer 35 are integrated with respect to the first embodiment. Thereby, the number of parts can be reduced and the cost can be reduced.

(Eighth embodiment)
In the first embodiment, the inner hub 33 is divided into the first inner hub 331 and the second inner hub 332, and the spring 34 is interposed between the first inner hub 331 and the second inner hub 332. However, in the eighth embodiment, as shown in FIG. 10, the inner hub 33 is integrally formed, and the spring 43 is disposed between the limiter 37 and the stopper 39. The spring 43 generates a biasing force in a direction in which the limiter 37 is pulled away from the stopper 39. In the example of FIG. 10, the spring 43 is formed in a coil shape.

  According to the present embodiment, even if the breaking portion 37c of the limiter 37 is broken, the hub connecting portion 37a of the limiter 37 is not pulled away from the rotating shaft connecting portion 37b, and the urging force of the spring 43 moves toward the rotating shaft connecting portion 37b. Pressed.

  For this reason, the driven-side rotating body (specifically, the hub connecting portion 37a, the first inner hub 331, the elastic member 32, the outer hub 31, and the armature 30) separated from the rotating shaft 11 by the breaking of the breaking portion 37c. It can be prevented from falling off.

  Further, since the hub connecting portion 37a is pressed against the rotating shaft connecting portion 37b by the urging force of the spring 34, the posture of the driven rotating body separated from the rotating shaft 11 can be stabilized. For this reason, it is possible to prevent the armature 30 from colliding with the pulley 21 locally to generate abnormal noise or adhere to the pulley 21.

(Other embodiments)
In each of the above-described embodiments, the rotary shaft connecting portion 37b of the limiter 37 is screwed directly to the rotary shaft 11 of the compressor 10, but the rotary shaft connecting portion 37b of the limiter 37 is indirectly connected via an interposed member. The screw 10 may be screwed to the rotary shaft 11 of the compressor 10.

  In each of the above-described embodiments, the example in which the power transmission device 20 is applied to intermittent rotation driving force from the engine to the compressor 10 has been described. However, the present invention is not limited to this, and driving of an engine or an electric motor or the like is not limited thereto. The present invention is widely applicable to intermittent transmission of power between a power source and a generator operated by a rotational driving force.

10 Compressor (Drive target device)
21 Pulley (drive-side rotating body)
22 Electromagnet 30 Armature (driven rotor)
33 Inner hub (driven rotor)
34 Spring (detaching means)
37 Limiter 39 Stopper 331 First inner hub 332 Second inner hub

Claims (10)

A driving side rotating body (21) that rotates by a rotational driving force output from a driving source;
A driven rotary body (30, 33) that rotates together with the rotary shaft (11) of the drive target device (10) by being connected to the drive side rotary body (21);
An electromagnet (22) for generating an electromagnetic force for connecting the driven side rotating body (30, 33) to the driving side rotating body (21);
Torque transmitted from the drive-side rotator (21) to the driven-side rotator (30, 33), which is a member that connects the driven-side rotator (30, 33) and the rotating shaft (11). A limiter (37) for breaking the driven rotating body (30, 33) from the rotating shaft (11) by breaking by an axial force when the torque exceeds a predetermined torque;
The driven rotary body (30, 33) and the rotary shaft (11) which are formed to protrude radially outward from the rotary shaft (11) and are separated from the rotary shaft (11) by breaking the limiter (37). And a stopper (39) that abuts in the axial direction.   Characterized in that it comprises pull-off means (34) for pulling the driven-side rotator (30, 33) separated from the rotating shaft (11) by breaking the limiter (37) from the drive-side rotator (21). The power transmission device according to claim 1. The driven rotor (30, 33) generates torque from the armature (30) attracted to the drive rotor (21) by the electromagnetic force and the rotating shaft (11) from the armature (30). An inner hub (33) for transmitting,
The inner hub (33) includes a first inner hub (331) connected to the armature (30), and a second inner hub (332) to which torque from the first inner hub (331) is transmitted by frictional force. ) And divided into
The power transmission device according to claim 2, wherein the separating means (34) is a spring disposed between the first inner hub (331) and the second inner hub (332). The second inner hub (332) has a cylindrical portion (332b) in which the rotating shaft (11) is inserted and in axial contact with the first inner hub (331).
The power transmission device according to claim 3, wherein the spring (34) is disposed between the cylindrical portion (332b) and the first inner hub (331). The driven rotor (30, 33) generates torque from the armature (30) attracted to the drive rotor (21) by the electromagnetic force and the rotating shaft (11) from the armature (30). An inner hub (33) for transmitting,
The inner hub (33) includes a cylindrical portion (33a) in which the rotating shaft (11) is inserted, and the cylindrical portion (33a) and the armature (30) extending radially outward from the cylindrical portion (33a). And a connecting portion (33b) for connecting the
The power transmission device according to claim 2, wherein the spring (34) is disposed outside the cylindrical portion (33b). A spring (40) for biasing the driven-side rotating body (30, 33) to the opposite side of the stopper (39);
The limiter (37)
A hub connecting portion (37a) connected to the driven side rotating body (30, 33);
A rotating shaft connecting portion (37b) connected to the rotating shaft (11);
The hub connecting portion (37a) and the rotating shaft connecting portion (37b) are connected in the axial direction, and torque transmitted from the driving side rotating body to the driven side rotating body (30, 33) is a predetermined torque. A break portion (37c) that breaks due to an axial force when it becomes the above and separates the hub connection portion (37a) from the rotary shaft connection portion (37b);
The spring (40) is disposed between the driven-side rotating body (30, 33) and the hub connecting portion (37a),
The stopper (39) is formed so as to abut on the hub connecting portion (37a) separated from the rotating shaft connecting portion (37b) by the breaking of the breaking portion (37c) in the axial direction. The power transmission device according to claim 1, wherein the power transmission device is a power transmission device.   A slide mechanism (41) is provided between the first inner hub (331) and the second inner hub (332) and guides the sliding movement of the first inner hub (331) in the axial direction. The power transmission device according to claim 3.   The power transmission device according to any one of claims 1 to 7, wherein a labyrinth mechanism (42) is formed by the stopper (39) and the limiter (37). The driven rotor (30, 33) generates torque from the armature (30) attracted to the drive rotor (21) by the electromagnetic force and the rotating shaft (11) from the armature (30). An inner hub (33) for transmission, and a spacer (35) interposed between the inner hub (33) and the rotating shaft (11),
The power transmission device according to claim 1, wherein the inner hub (33) and the spacer (35) are integrally formed. A spring (43) for urging the driven-side rotating body (30, 33) to the side opposite to the stopper (39);
The limiter (37)
A hub connecting portion (37a) connected to the driven side rotating body (30, 33);
A rotating shaft connecting portion (37b) connected to the rotating shaft (11);
The hub connecting portion (37a) and the rotating shaft connecting portion (37b) are connected in the axial direction, and torque transmitted from the driving side rotating body to the driven side rotating body (30, 33) is a predetermined torque. A break portion (37c) that breaks due to an axial force when it becomes the above and separates the hub connection portion (37a) from the rotary shaft connection portion (37b);
The power transmission device according to claim 1, wherein the spring (43) is disposed between the rotating shaft coupling portion (37b) and the stopper (39).

Images