JP2000356226A - Torque limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque limiter capable of preventing welding of a disc and friction parts with simple structure. SOLUTION: A disc 7 connected to the input shaft 4 of a refrigerant compressor 3 is formed of metal, while a pulley 1 and a pressure plate 8 constituting first and second friction parts 1c, 8a are formed of resin. When the refrigerant compressor 3 is locked and excessive load torque acts upon a friction engaging face, a slip is generated between the disc 7 and the first and second friction parts 1c, 8a to cut off the transmission of torque. The first and second friction parts 1c, 8a formed of resin are dissolved by this slip to prevent welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter for interrupting the transmission of torque when a torque difference between a rotary driving body and a rotation driven body exceeds a set torque. It is suitable for application to a refrigerant compressor.

[0002]

2. Description of the Related Art For example, when a variable displacement compressor is used as a refrigerant compressor for an automobile refrigeration cycle, it is not necessary to operate the compressor intermittently for controlling the capacity of the refrigeration cycle. There is no need to mount an electromagnetic clutch that interrupts power transmission. However, when an abnormality such as lock occurs in the compressor such as a burn-in failure of the compressor or the like, a belt that transmits rotational power to the compressor slips, and a belt breakage occurs. In particular, when the belt that transmits rotational power to the compressor of the automobile is a common belt with various auxiliary devices other than the compressor (such as a battery charging generator, a water pump for engine cooling, and a power steering hydraulic pump),
If the belt breaks, the car cannot run.

[0003]

In order to avoid the above-mentioned problems, a torque limiter is provided for interrupting the power transmission path to the compressor when the transmission torque rises above a set torque, for example, when the compressor is locked. Are known. 2. Description of the Related Art As a conventional torque limiter, there is a torque limiter using a disk and a friction portion that frictionally engages with the disk. Conventional discs and friction parts are both made of metal, and when the torque limiter is activated and a slip occurs between the disc and the friction parts, the heat may cause the disc and friction parts to weld together. Would. In order to avoid this problem, the conventional torque limiter displaces the disc in the axial direction by, for example, rotating the disc by sliding when the limiter is actuated, weakening the pressing force between the disc and the friction portion, and causing the friction portion to idle. I have to. However, the conventional torque limiter requires a complicated mechanism for rotating the disc by sliding when the limiter is operated and displacing the disc in the axial direction, and there is a problem that the cost is increased due to an increase in processing costs and assembly costs. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a torque limiter which can prevent welding between a disk and a friction portion with a simple structure.

[0005]

[Means for Solving the Problems] A torque limiter employing the means of claim 1 is adapted to be used when a torque difference greater than a set torque is generated between a rotary driving body and a rotary follower. Then, a slip occurs between the disk and the friction portion, and the transmission of torque between the rotary driving body and the rotary driven body is interrupted. During operation of this torque limiter, slip occurs between the disk and the friction part, but resin or rubber is provided at the frictional engagement portion between the disk and the friction part, so that the resin or rubber is heated by heat. The transmission of torque can be interrupted without melting or welding. As described above, the simple structure in which the resin or the rubber is provided in the friction engagement portion can prevent welding during the operation of the limiter, thereby reducing the processing cost and the assembly cost of the components constituting the torque limiter, and reducing the manufacturing cost. be able to.

The torque limiter adopting the means of claim 2 has a simple structure in which at least one of the member constituting the friction portion or the disk is formed of resin or rubber, so that the number of parts is small. And the processing cost and assembly cost of the components constituting the torque limiter can be reduced, and the manufacturing cost can be reduced.

[0007] The torque limiter employing the means of claim 3 has a simple structure in which a resin plate or a rubber plate is interposed between the friction portion and the disk, so that the number of parts is small. In addition, the processing cost and the assembly cost of the components constituting the torque limiter can be reduced, and the manufacturing cost can be reduced.

The torque limiter adopting the means of claim 4 has a simple structure in which a resin film or a rubber film is provided on at least one surface of the friction portion or the disk, so that the number of parts is small. And the processing cost and assembly cost of the components constituting the torque limiter can be reduced, and the manufacturing cost can be reduced.

The torque limiter adopting the means of claim 5 has a simple structure in which the disc is pressed against the pulley by the pressing plate, so that the number of parts is small and reliable operation can be obtained. Can be.

According to a sixth aspect of the present invention, in the torque limiter employing the sixth aspect, the disk and the pressing plate are arranged on the inner diameter side of the belt groove of the pulley. That is, the structure is such that the torque limiter is housed inside the pulley, and the size can be reduced.

[0011]

Embodiments of the present invention will be described with reference to the drawings. [First Embodiment] In this embodiment, the torque limiter according to the present invention is applied to a rotational torque input section of a refrigerant compressor. FIG. 1 is a sectional view of a power transmission device of the refrigerant compressor, and FIG. Is an enlarged view of a portion J in FIG. 1, and FIG. 3 is a front view of the power transmission device.

The power transmission device is connected to a refrigerant compressor 3 via a torque limiter 2 from a pulley 1 (corresponding to a rotary drive).
Is transmitted to the input shaft 4 (corresponding to a rotation follower).

The pulley 1 is a multi-stage V-belt (not shown)
And rotates by receiving a rotational torque from an automobile engine (not shown) via the. The pulley 1 is made of a high-hardness resin such as epoxy (for example, a thermosetting resin), and has a multi-belt groove 1a on which a multi-stage V-belt is stretched on the outer peripheral side, and a bearing mounting rotor 1b on the inner peripheral side. ,
A first friction portion 1c described later is integrally formed inside the belt groove 1a. The pulley 1 is rotatable via a bearing 5, and the bearing 5 is supported on the outer periphery of a cylindrical projection 6 a formed on a housing 6 of the refrigerant compressor 3.

The torque limiter 2 rotates integrally with the disk 7 rotating integrally with the input shaft 4 (rotary follower) and the pulley 1 (rotary driving body), and is pressed against the disk 7 to frictionally engage with it. It has first and second friction portions 1c and 8a. The first friction portion 1c in this embodiment is provided on the pulley 1, and a ring portion is formed on the inner diameter side of the belt groove 1a of the pulley 1 so as to protrude substantially in the axial front side. The front surface of the convex ring portion is provided so as to frictionally engage with the disk 7. Further, the second friction portion 8a in this embodiment is provided on the pressing plate 8 that presses the disk 7.

The pressing plate 8 sandwiches the disk 7 between the pressing plate 8 and the pulley 1, and is made of a high-hardness resin such as epoxy (for example, a thermosetting resin) or an elastic deformation such as nylon. It is made of a possible resin (for example, a thermoplastic resin). The pressing plate 8 is also mounted on the inner diameter side of the belt groove 1a of the pulley 1, and the threaded portion 8b formed on the outer peripheral side is screwed into the threaded portion 1d on the inner periphery of the belt groove 1a. The second friction portion 8 a is provided so as to press the disk 7.

The disk 7 is made of an iron-based metal, is arranged on the inner diameter side of the belt groove 1a of the pulley 1, and is provided on the first and second friction portions 1c, 8a as shown in FIG. It is pinched and frictionally engaged with the first and second friction portions 1c and 8a, and transmits the rotational torque transmitted to the pulley 1 and the pressing plate 8 to the disk 7. The inner circumference of the disk 7 is prevented from rotating around the input shaft 4 by involute spline fitting or the like, and is connected to the input shaft 4 by bolts (not shown).

When a torque difference equal to or greater than a set torque is generated between the pulley 1 (rotary driving body) and the input shaft 4 (rotary driven body), the torque limiter 2 causes the disc 7 and the disk 7 to rotate due to the torque difference. A slip occurs between the first and second friction portions 1c and 8a to interrupt the torque transmission. The set torque at which the slip occurs depends on the pressing force of the pressing plate 8, the friction coefficient of the friction engagement surface, and the like. It is set. The set torque is the maximum load torque of the refrigerant compressor 3 (for example, 2 kgf
.M) by a predetermined value (for example, 3.5 kgf)
M) is set. Further, the engagement force of the friction engagement surface can be variously set by providing irregularities or the like on the surfaces of the disk 7 and the first and second friction portions 1c and 8a.

In this embodiment, the refrigerant compressor 3
Although the specific structure of the refrigerant compressor 3 of this embodiment is omitted, the refrigerant compressor 3 of this embodiment is known as a continuous displacement variable type. For example, a swash plate type, a piston driving swash plate reciprocating like a wobble type The refrigerant discharge capacity is continuously varied between 0% and 100% by changing the inclination angle.
Since the refrigerant compressor 3 of the continuous variable capacity type can control the refrigerant discharge capacity, it is not necessary to mount an electromagnetic clutch for connecting and disconnecting the refrigerant compressor 3.

[Operation of First Embodiment] First, the operation of the refrigerant compressor 3 during normal operation will be described. The rotation of the crank pulley of the automobile engine is transmitted to the pulley 1 via the belt, and the pulley 1 is driven to rotate. The rotational torque transmitted to the pulley 1 is transmitted to the disk 7 frictionally engaged with the pulley 1 and the pressing plate 8, and transmitted from the disk 7 to the input shaft 4 of the refrigerant compressor 3. The refrigerant compressor 3 operates by the rotation torque transmitted to the input shaft 4.

When the refrigerant compressor 3 is locked, an excessive load torque exceeding the set torque (for example, 3.5 kgf · m) acts on the friction engagement surface, and the disk 7 and the first and second friction portions 1 c , 8a. When the slip occurs, the first and second friction portions 1c and 8a made of resin are formed.
Is melted by the frictional heat, the friction coefficient of the frictional engagement surface drops sharply, and the transmission of torque from the pulley 1 to the refrigerant compressor 3 is interrupted.

[Effects of the first embodiment] As described above, when the refrigerant compressor 3 is locked and the torque limiter 2 is operated, the disc 7 and the first and second friction portions 1c and 8a are connected. Although slip occurs between the surfaces, the heat generated by the slip melts the surfaces of the first and second friction portions 1c and 8a formed of the resin, so that the transmission of torque can be interrupted without welding. As described above, welding during the limiter operation can be prevented by the simple structure in which the pulley 1 and the pressing plate 8 constituting the first and second friction portions 1c and 8a are made of resin, and the components constituting the torque limiter 2 And the cost of assembling can be reduced, and the cost of the torque limiter 2 can be reduced.

Further, the torque limiter 2 of this embodiment
Has a structure housed inside the belt groove 1a of the pulley 1, and the mountability of the refrigerant compressor 3 equipped with the pulley 1 with the torque limiter 2 is excellent in a narrow engine room.

[Other Embodiments in First Embodiment] In the first embodiment, the pulley 1 and the pressing plate 8 constituting the first and second friction portions 1c and 8a are formed of resin, and the disk 7 is formed of metal. The first and second friction portions 1 have been described as an example.
The pulley 1 and the pressing plate 8 constituting c and 8a may be formed of metal, and the disk 7 may be formed of resin. Further, three of the pulley 1, the pressing plate 8, and the disk 7 constituting the first and second friction portions 1c and 8a may be formed of resin.

The pulley 1 and the pressing plate 8 forming the first and second friction portions 1c and 8a are made of resin, and the disk 7 is made of metal. Part 1c,
The pulley 1 and the pressing plate 8 forming the 8a are formed of a hard rubber material, the disk 7 is formed of metal, or the pulley 1, the pressing plate 8 forming the first and second friction portions 1c and 8a, and Three of the disks 7 may be formed of a hard rubber material.

[Second Embodiment] FIG. 4 is an enlarged sectional view of a main part of a torque limiter 2 showing a second embodiment. This second
In the embodiment, three of the pulley 1, the pressing plate 8, and the disk 7 constituting the first and second friction portions 1c, 8a are formed of, for example, an iron-based metal, and the first and second friction portions 1c, 8a are formed. And a disk 7 with a resin plate 10 interposed therebetween. The resin plate 10 may be a thermoplastic resin or a thermosetting resin.

In this embodiment, when the refrigerant compressor 3 is locked, the disc 7 and the first and second discs are caused by excessive load torque.
Slip occurs between the friction portions 1c and 8a. Then
The resin plate 10 interposed between the disk 7 and the first and second friction portions 1c and 8a is melted by the heat of the friction caused by the slip, and
And the first and second friction portions 1c and 8a are prevented from welding. Since the torque limiter 2 of the second embodiment has a simple structure in which a resin is interposed between the first and second friction portions 1c and 8a and the disk 7, the cost of the torque limiter 2 can be reduced. .

[Other Embodiments in Second Embodiment] The resin plate 10 shown in the second embodiment may be used instead of a rubber plate.

[Third Embodiment] FIG. 5 is an enlarged sectional view of a main part of a torque limiter 2 according to a third embodiment. This third
In the embodiment, three of the pulley 1, the pressing plate 8, and the disk 7 constituting the first and second friction portions 1c, 8a are formed of, for example, an iron-based metal, and at least the outer surface of the disk 7 is made of resin. The film 11 is formed by coating or the like. Note that the resin film 11 may be a thermoplastic resin or a thermosetting resin.

In this embodiment, when the refrigerant compressor 3 is locked, the disc 7 and the first and second discs are caused by excessive load torque.
Slip occurs between the friction portions 1c and 8a. Then
The resin film 11 formed on the surface of the disk 7 is melted by the heat of friction caused by sliding, and the disk 7 and the first and second friction portions 1c, 8
a to prevent the occurrence of welding. Since the torque limiter 2 of the third embodiment has a simple structure in which the resin film 11 is formed on the surface of the disk 7, the cost of the torque limiter 2 can be reduced.

[Other Embodiments in Third Embodiment] In the third embodiment, an example in which the resin film 11 is formed on the disk 7 has been described. A resin film 11 may be provided on the surfaces of the first and second friction portions 1c and 8a. Further, the disk 7 and the first and second friction portions 1c and 8a
May be provided with a resin film 11 on the surface of. Further, a rubber film may be used instead of the resin film 11.

[Other Embodiments] In each of the above embodiments,
Although the example in which the first friction portion 1c is provided integrally with the pulley 1 has been described, the first friction portion 1c may be provided by a member different from the pulley 1. In each of the above embodiments, the disk 7 is provided on the side of the rotation follower (the side of the input shaft 4 of the refrigerant compressor 3), and the friction portion (first,
The second friction portions 1c, 8a) are connected to the rotary driving body side (the pulley 1 side).
However, the disk 7 is provided on the rotation driving body side (the pulley 1 side), and the friction portions (the first and second friction portions 1c, 8) are provided.
a) may be provided on the rotation follower side (the input shaft 4 side of the refrigerant compressor 3).

In each of the above-described embodiments, the example in which the number of the disks 7 is one has been described. However, a multi-plate type torque limiter 2 may be used by using a plurality of the disks 7. Such a multi-plate system is effective when the limiter operating torque is large. In each of the above embodiments, examples in which the present invention is applied to the refrigerant compressor 3 of the refrigeration cycle for automobiles have been described. However, various torque limiters 2 that interrupt the transmission of torque when a torque difference equal to or more than a set torque occurs. It is widely applicable to In each of the above-described embodiments, the example in which the torque limiter 2 is applied to the input means of the rotational torque has been described. However, the torque limiter 2 may be disposed at another portion such as the output means of the rotational torque.

[Brief description of the drawings]

FIG. 1 is a sectional view of a power transmission device of a refrigerant compressor (first embodiment).

FIG. 2 is an enlarged view of a portion J in FIG. 1 (first embodiment).

FIG. 3 is a front view of the power transmission device (first embodiment).

FIG. 4 is an enlarged sectional view of a main part of a torque limiter (second embodiment);
Embodiment).

FIG. 5 is an enlarged sectional view of a main part of a torque limiter (third part);
Embodiment).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulley (rotary drive) 1a Belt groove 1c 1st friction part 2 Torque limiter 4 Compressor input shaft (rotary follower) 7 Disk 8 Press plate 8a 2nd friction part 10 Resin plate 11 Resin film

Claims (6)

[Claims] 1. A torque limiter interposed between a rotary driving body and a rotation driven body, wherein the torque limiter interrupts transmission of torque when a torque difference greater than a set torque is generated. A disk that rotates integrally with one of the body and the rotation follower, and a friction portion that rotates integrally with the other of the rotation driver and the rotation follower and that is pressed against the disk and frictionally engages. A torque limiter, wherein a resin or rubber is provided in a frictional engagement portion between the disk and the frictional portion. 2. The torque limiter according to claim 1, wherein one of the member forming the friction portion or the disk is formed of resin or rubber, and the member forming the friction portion or the other of the disk is formed of metal or metal. A torque limiter made of resin or rubber. 3. The torque limiter according to claim 1, wherein the member constituting the friction portion and the disk are formed of metal, and a resin plate or a rubber plate is interposed between the friction portion and the disk. A torque limiter. 4. The torque limiter according to claim 1, wherein the member constituting the friction portion and the disk are formed of metal, and a resin film or a rubber film is formed on at least one surface of the friction portion or the disk. A torque limiter, which is provided. 5. The torque limiter according to claim 1, wherein a member constituting the friction portion is a pulley that is driven to rotate by a V-belt, and is fixed to the pulley. And a pressing plate for pressing the pulley against the pulley. 6. The torque limiter according to claim 5, wherein said disc and said pressing plate are arranged on an inner diameter side of a belt groove in said pulley.