JP2009299875A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device with a limiter function for preventing the fall-off of a hub after the operation of a limiter. <P>SOLUTION: The power transmission device includes a pulley 2 to be dynamically connected to a driving source, the hub 4 to be unevenly fitted and joined to the pulley 2, and a power interrupting member 5 laid between the hub 4 and a rotating shaft 3 of driven equipment for interrupting the transmission of excessive torque. The pulley 2 includes a recessed portion 21, and the hub 4 includes a protruded portion 44 to be fitted to the recessed portion 21. On the hub 4, a damper lip 45 is provided which extends to the radial outside beyond the protruded portion 44 and which is pressed into the recessed portion 21 of the pulley 2 to hold the hub 4 and the pulley 2 in a joined condition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power transmission device in which a hub and a pulley are fitted and connected dynamically, and in particular, a power transmission device that has a limiter function and prevents the hub from falling off after the limiter is actuated. It is about.

Conventionally, in a power transmission device that transmits power of a driving source to a compressor that is a driven device, a hub and a pulley having a damper damping mechanism such as rubber are provided, and a recess is provided in the pulley, while the hub side is also elastic. There are some which are made of a member and formed with a convex portion 44 fitted into the concave portion, so that both are concavely and convexly fitted in the axial direction.
Further, in such a power transmission device, a torque limiter (power cutoff member) that screw-fits a part of the power transmission part in order to avoid problems such as belt breakage for power transmission when the compressor seizes. Is provided.

  By the way, in the power transmission device having such a structure, when the compressor is seized and excessive torque is generated, the torque limiter is broken. When the torque limiter is broken, the pulley and the hub are only inserted in the axial direction by the concavo-convex portions 44, so the hub easily falls off the pulley.

  Further, in Patent Document 1, when the compressor is seized, in order to avoid problems such as belt breakage for power transmission, a protrusion is provided on the damper part of the hub, and the protrusion is used as a pulley. The hub is prevented from falling off by the structure that is attached to the formed hole portion.

JP2007-1113646

In addition, a configuration in which a mechanism for preventing the hub from falling off is provided on the side surface of the fitting portion between the hub and the pulley has been proposed. There is.
The present invention has been proposed in order to improve the above-described problems, and provides a power transmission device that does not complicate the mold structure and can effectively prevent the hub from falling off. For the purpose.

  In order to solve the above-mentioned problems, in the invention described in claim 1, a pulley (2) that is dynamically connected to a drive source, a hub (4) that is coupled to the pulley (2) by concave and convex fitting, and a hub In the power transmission device (1) comprising a power shut-off member (5) interposed between (4) and the rotating shaft (3) of the driven device and blocking transmission of excessive torque, the pulley (2) Includes a concave portion (21), the hub (4) includes a convex portion (44) fitted to the concave portion (21), and the hub (4) has a radially outer side than the convex portion (44). And a damper lip (45) that maintains a coupling state between the hub (4) and the pulley (2) by being press-fitted into the recess (21) of the pulley (2).

  Thus, even if the power shut-off member (5) acts due to excessive torque and the restraint state between the hub (4) and the rotating shaft (3) of the driven device is cut off, the hub (4) remains in the pulley (2 ) And the damper lip (45) can maintain the concave-convex fitting state, so that the hub (4) can be prevented from falling off.

  In the invention according to claim 2, the hub (4) comprises an inner hub (51), an elastic part (42), and an outer ring (43) surrounding the elastic part (42), The damper lip (45) is provided integrally with the outer peripheral surface of the outer ring (43) so as to protrude in a diameter-expanded manner and elastically.

When the hub (4) is fitted to the pulley (2), the damper lip (45) on the outer periphery of the outer ring (43) is pressed into the recess (21) in the pulley (2) in an elastically deformed state. The holding force for holding the hub (4) on the pulley (2) without dropping off can be ensured.
At this time, since the damper lip (45) can be brought into close contact with the recess (21) of the pulley (2), the sealing performance is improved and the entry of foreign matter and liquid can be completely prevented. .

  In the invention according to claim 3, the hub (4) has a damper lip (45) protruding from the elastic part (42) outside the outer ring (43) at predetermined intervals, and the damper lip (45). Is characterized in that a protrusion (45a) is formed toward the pulley (2) to be fitted.

Thereby, it becomes easier to assemble the pulley (2).
When the damper lip (45) is press-fitted into the recess (21) of the pulley (2), the protrusion (45a) of the damper lip (45) adds to the elastic force of the damper lip (45), and the hub (4) It can be pressed so as not to fall off, and the holding force can be secured. Thereby, sealing performance improves and it can prevent that foreign materials, such as dust, and liquids, such as water, penetrate | invade deeply into the recessed part (21) of a pulley (2).

  In the invention according to claim 4, the hub (4) includes an inner hub (41), an elastic part (42), and an outer ring (43) surrounding the elastic part (42), and a pulley. In the concave portion (21) in (2), a fitting hole (23) for fitting the convex portion (44) in the hub (4) is provided.

  Thereby, weight reduction of a hub (4) is achieved and a convex part (44) is fittingly locked by the fitting hole (23) in the bottom part side of the recessed part (21) in a pulley (2). The waterproof and dustproof function can be secured from the front side and the rear side of the power transmission device (1). Moreover, the holding force of the hub (4) is ensured, and when removing the hub (4), the maintenance can be improved by pushing the hub out of the fitting hole (23).

  Further, the invention according to claim 5 is characterized in that the edge of the pulley (2) is chamfered or rounded.

  Thus, when the hub (4) is fitted into the recess (21) of the pulley (2), the damper lip (45) projecting in an enlarged and elastic manner on the outer peripheral surface of the outer ring (43), The edge of the chamfered pulley (2) reaching the recess (21) of the pulley (2) is urged to be deformed without stress, and the pulley (2) and the hub (4) are smoothly fitted.

  Note that the reference numerals in parentheses attached to the respective means described in the above means are an example showing the correspondence with the specific means described in the embodiments described later.

(First embodiment)
FIG. 1 shows a first embodiment of a power transmission device 1.
This power transmission device 1 is connected to a rotating shaft 3 of a compressor, which is a driven device, from a pulley 2 that is dynamically connected to a drive source, via a hub 4 and a power cutoff member 5 (hereinafter referred to as a torque limiter 5). It is configured to transmit power. The pulley 2 and the hub 4 are provided coaxially. Note that the present invention is not limited to the configuration in which the torque limiter 5 that is a power cutoff member is provided, but also includes the power transmission device 1 having a configuration in which the hub 4 is directly fixed to the rotating shaft 3.

The pulley 2 is rotatably attached to a cylindrical boss portion 61 provided on one end side of the casing 6 of the compressor via a bearing 7, a ring 8, and a ring member 9.
The pulley 2 is preferably molded from a thermoplastic synthetic resin material, and a plurality of recesses 21 for fitting the hub 4 described later are formed by ribs 22 at equal intervals. The pulley 2 may be made of a metallic material.
When the pulley 2 is made of resin, the pulley 2, the ring member 9 and the bearing 7 can be integrated by insert molding. A belt (not shown) is wound around the outer peripheral surface of the pulley 2, and the pulley 2 is rotated by external power such as an engine or a motor.
The bearing 7 is fitted to the boss portion 61 and is pivoted by an end portion 62 of the boss portion 61 and a first retaining ring (snap ring) 10 fitted in a groove formed on the outer peripheral surface of the boss portion 61. Directional movement is blocked. Moreover, the casing 6 and the rotating shaft 3 are sealed by a shaft seal device 11 to prevent leakage of refrigerant, oil, and the like to the outside. Further, the shaft seal device 11 is also prevented from moving in the axial direction by a second retaining ring (snap ring) 12 fitted in a groove formed on the inner peripheral surface of the boss portion 61.

  The tip of the rotary shaft 3 of the compressor protrudes from the casing 6, and the tip of the tool is a tool-shaped part 31 formed in a tool shape in order from the tip, a screw part 32 and a screw part in which screws are formed on the outer periphery. The step portion 33 is formed between the screw portion 32 and the large-diameter portion. A washer 13 is inserted at the tip of the rotating shaft 3, and an end A 131 of the washer 13 is in contact with the stepped portion 33. Further, a torque limiter 5 which will be described later in detail is fixed to the screw portion 32 on the rotary shaft 3 by screwing. For fixing the torque limiter 5 to the rotating shaft 3, other fixing methods such as spline engagement and bolt mounting can be appropriately employed in addition to screwing.

  Here, the torque limiter 5 as the power shut-off member has a large outer diameter portion and a small outer diameter portion in a rectangular tube or a cylindrical shape, and the outer peripheral surface of the large outer diameter portion is fitted to the hub 4 described later. This is part 51. A screw portion 52 is formed on the inner peripheral surface of the small outer diameter portion, and is screwed to the screw portion 32 of the rotating shaft 3. The inner diameter of the large outer diameter portion is slightly larger than the inner diameter of the small outer diameter portion, and a cutout portion 53 is formed at the transition portion of the inner peripheral surface of both, and the torque limiter 5 receives an excessive axial force. Sometimes it breaks easily.

The hub 4 includes an inner hub 41, an elastic part 42, and an outer ring 43.
The inner peripheral surface 41 a of the inner hub 41 is formed in a shape substantially matching the outer peripheral surface of the torque limiter 5, and is a caulking portion that is fitted to the outer peripheral surface (fitting portion) 51 of the large outer diameter portion of the torque limiter 5. 41a is provided. In the present embodiment, as shown in FIG. 2, the caulking portion 41a of the hub 4 is formed at two locations, and is opposed diagonally among the fitting portions 51 of the torque limiter 5 formed in a hexagonal shape. It is formed opposite to the two corners.
In this way, the hub 4 and the torque limiter 5 are fixed by fitting. Further, the rear end face 41 b of the hub 4 is in contact with the end B 132 of the washer 13, so that the hub 4 is sandwiched between the torque limiter 5 and the washer 13. The outer peripheral surface of the inner hub 41 is coupled to the elastic portion 42 by adhesion or the like.
In the above description, the hub 4 is described as being composed of the inner hub 41, the elastic portion 42, and the outer ring 43. However, the outer ring 43 is omitted and the hub 4 is the inner hub. You may comprise by 41 and 41 of elastic parts (after-mentioned).

The outer ring 43 has a cylindrical shape and is formed of a metallic material like the inner hub 41.
The elastic portion 42 is formed of an elastic material such as rubber or resin, and is disposed between the inner hub 41 and the outer ring 43 and joined to the outer peripheral surface of the inner hub 41 and the inner peripheral surface of the outer ring 43 by means such as adhesion. Has been. Alternatively, these three members may be integrally formed by insert molding. The elastic portion 42 not only functions as a torque transmission but also functions as a torque damper.

  The outer ring 43 is surrounded by the elastic portion 42 and the elastic portion foot portion 42a, and extends toward the concave portion 21 of the pulley 2, and the three surfaces (outer peripheral surfaces) of the upper surface, the side surface, and the lower surface are The convex portion 44 is fitted into the concave portion 21 on the pulley 2 side.

The convex portion 44 is provided with a damper lip 45 that extends to the outer side in the radial direction than the convex portion 44 and press-fits into the concave portion 21 of the pulley 2 to maintain the coupling state between the hub 4 and the pulley 2. ing.
The damper lip 45 is integrally provided on the outer peripheral surface of the elastic portion 42 that surrounds the outer ring 43, and is configured to protrude elastically in a diameter-expanding manner, that is, vertically.
In addition, since the surface side where the convex portion 22 of the pulley 2 is formed is exposed to the outside, foreign matters such as dust and liquid easily enter the concave portion 21 of the pulley 2.

Further, as shown in FIG. 3, the damper lip 45 is press-fitted at its outer peripheral end toward the concave portion 21 between the convex portions 22 of the pulley 2 by the elastic force of the elastic portion 42, so that the hub 4 is fitted into the pulley 2. The holding force to hold is ensured. At that time, the damper lip 45 seals the concave portion 21 between the convex portions 22 of the pulley 2 so that the front surface of the convex portion 22 is completely covered.
In addition, the edge part of the front surface of the convex part 22 of this pulley 2 is chamfered, and has a round shape.

In the power transmission device 1 configured as described above, the hub 4 and the pulley 2 are coupled by inserting the convex portion 44 on the hub 4 side into the concave portion 21 on the pulley 2 side (see FIG. 4). .
At this time, since the annular damper lip 45 is provided so as to protrude from the front side portion adjacent to the convex portion 44 of the elastic portion 42 to the radially outer side than the convex portion 44, the damper lip 45 is The elastic force of the elastic part 42 is pressed into the wall surface of the recess 21 on the pulley 2 side from the edge side of the pulley 2 while being elastically contacted, and the hub 4 and the pulley 2 are in a fitted state (FIG. 5). reference).
At that time, since the damper lip 45 is in a pressure contact state in a folded state on the wall surface of the recess 21 on the pulley 2 side, the sealing property is improved and the front surface of the concave and convex fitting portion is completely covered. It is possible to prevent foreign matter such as water and liquid such as water from penetrating deep into the recess 21 of the pulley 2 and to prevent abnormal wear and the like of this portion.

  Thus, the hub 4 and the pulley 2 are coupled in a state where the damper lip 45 is elastically pressed against the wall surface of the concave portion 21 of the pulley 2 by the elastic force of the elastic portion 42, for example, the torque limiter 5. The hub 4 is removed from the pulley 2 by the damper lip 45 even if the shaft breaks due to excessive axial force or the rotating shaft 3 is broken due to adhesion with the rotating shaft 3 of the compressor. Can be held without.

(Second Embodiment)
FIG. 6 shows the hub 4 fitted to the pulley 2 according to the second embodiment.
In the components of the hub 4 here, the components that are substantially the same as those of the hub 4 in the first embodiment are denoted by the same reference numerals.

  In the hub 4 in FIGS. 6 and 7, the damper lip 45 projects from the elastic portion 42 outside the outer ring 43 at predetermined intervals. An appropriate protrusion 45a can be formed on the damper lip 45 regardless of continuous discontinuity toward the pulley 2 to be fitted (see FIGS. 8A, 8B, and 8C). .

  With such a configuration, it is easier to assemble the pulley 2, and when the damper lip 45 is press-fitted into the recess 21 of the pulley 2, the protrusion 45 a of the damper lip 45 adds to the elastic force of the damper lip 45. Thus, the hub 4 is pressed so as not to drop off, the holding force is ensured, the sealing performance is improved, and foreign matter such as dust and liquid such as water are prevented from entering deeply into the recess 21 of the pulley 2. (See FIG. 9).

(Third embodiment)
FIG. 10 shows a power transmission device 1 according to the third embodiment.
In the power transmission device 1 here, the hub 4 is configured by the inner hub 41, the elastic portion 42, and the two members, omitting the outer ring 43, and on the bottom side of the concave portion 21 in the pulley 2, the convex portion in the hub 4. The fitting hole 23 for fitting the portion 44 is provided.

  With such a configuration, the hub 4 is reduced in weight, and the elastic portion 42 which is the convex portion 44 and the foot portion 42a in the elastic portion 42 are formed in the fitting hole 23 on the bottom side of the concave portion 21 in the pulley 2. By fitting and locking, the waterproof and dustproof function can be secured from the front side and the rear side of the power transmission device 1. Moreover, the holding force of the hub 4 is ensured, and when the hub 4 is removed, the maintenance can be improved by pushing the hub out of the fitting hole 23.

  In the above description, the power transmission device having a structure in which the hub 4 is fixed to the rotary shaft 3 via the torque limiter 5 has been described. However, the dust intrusion prevention unit of the present invention has a torque limiter unit on the rotary shaft. Of course, the present invention is also applicable to a power transmission device having a structure in which the hub is directly fixed to the rotating shaft.

It is a longitudinal section explanatory view of the power transmission device of a 1st embodiment of the present invention. It is the whole power transmission device front view of a 1st embodiment of the present invention. It is an enlarged view of the principal part of FIG. It is an upper half longitudinal cross-sectional view at the time of attaching a hub to the pulley in the power transmission device shown in FIG. It is an upper half longitudinal cross-sectional view after the assembly | attachment process shown in FIG. It is the whole hub front view in the power transmission device of a 2nd embodiment of the present invention. FIG. 7 is a cross-sectional view taken along HH shown in FIG. 6. It is the side view which showed three different embodiment which looked at the damper lip shown in FIG. 7 from I direction. FIG. 9 is an upper longitudinal sectional view when the hub shown in FIG. 8 is assembled to a pulley. It is upper half longitudinal cross-sectional explanatory drawing of the power transmission device of 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 Pulley 21 Recessed part 22 Rib 23 Fitting hole 3 Rotating shaft 31 Tool shape part 32 Screw part 33 Step part 4 Hub 41 Inner hub 41a Fitting part 41b Rear side end face 42 Elastic part 43 Outer ring 44 Convex part 45 Damper lip 45a Protruding part 5 Torque limiter 51 Fitting part 52 Screw part 53 Notch part 6 Casing 61 Boss part 62 End part 7 Bearing 8 Ring 9 Ring member 10 First retaining ring 11 Shaft seal device 12 Second retaining ring 13 Washer 131 End A
132 End B

Claims (5)

A pulley (2) operatively coupled to the drive source;
A hub (4) coupled to the pulley (2) by concave-convex fitting;
In the power transmission device (1) comprising a power cutoff member (5) interposed between the hub (4) and the rotating shaft (3) of the driven device and blocking transmission of excessive torque,
The pulley (2) includes a recess (21),
The hub (4) includes a convex portion (44) that fits into the concave portion (21),
Further, the hub (4) extends radially outward from the convex portion (44) and is press-fitted into the concave portion (21) of the pulley (2), whereby the hub (4) and the pulley ( 2. A power transmission device comprising a damper lip (45) that maintains a coupled state with 2). The hub (4) includes an inner hub (41), an elastic part (42), and an outer ring (43) surrounding the elastic part (42),
2. The power according to claim 1, wherein the damper lip (45) is integrally provided on the outer peripheral surface of the outer ring (43) so as to protrude in a diameter-expanding manner and elastically. Transmission device.   The hub (4) projects the damper lip (45) to the elastic part (42) outside the outer ring (43) at predetermined intervals, and is fitted to the damper lip (45). The power transmission device according to claim 1 or 2, wherein a protrusion (45a) is formed toward the power pulley (2) side. The hub (4) includes an inner hub (41) and an elastic part (42),
The power transmission device according to claim 1, wherein a fitting hole (23) for fitting the convex portion (44) of the hub (4) is provided in the concave portion (21) of the pulley (2). .   The power transmission device according to any one of claims 1 to 4, wherein an edge of the pulley (2) is chamfered or rounded.

Images