Power transmission device

The present invention relates to a power transmission device having a function of a torque limiter, and is particularly suitable for being incorporated and used in a vehicle compressor.

Conventionally, in a power transmission device that transmits power to a compressor, a method of connecting a hub provided with a damper damping mechanism such as rubber and a pulley is as shown in FIGS. 21 (a) and 21 (b). It was done. That is, when the pulley A is made of a metal such as iron, the pulley A is screwed as shown in FIG. 21 (a) and the pulley A and the hub B are connected by a bolt C or the like (see Patent Document 1). ). Reference numeral D is a damper rubber. Further, in the pulley A manufactured of resin or the like whose material strength is relatively lower than that of metal, as shown in FIG. 21 (b), the metal fitting E or the like that can be screw-fitted is inserted into the pulley by a method such as insert molding. The hub B and the pulley A were connected by connecting to A and connecting the metal fitting E and the bolt C by means such as bolt C (see Patent Document 2).

However, the joining method shown in FIG. 21 (b) has a problem that it is necessary to newly add parts such as metal fittings for screwing with bolts or the like, resulting in high cost. Further, for example, in the case of a pulley made of a resin material, it is necessary to provide the metal fitting by means such as insert molding, but there is also a problem that the bonding strength between the metal fitting and the resin material is remarkably lowered due to a change with time such as creep of the resin material. .. Furthermore, in the case of resin pulleys, reinforcing materials such as glass fibers are mixed in to improve the material strength, but it is difficult to orient the glass fibers as intended by inserting the metal fittings, and as a result, There is also a problem that the bond strength around the metal fittings cannot be obtained.

Therefore, in the prior art, as shown in FIG. 21 (c), a convex portion B1 is formed on the outer ring of the hub B, and a concave portion A1 is formed on the inner circumference of the resin pulley A, and each is fitted (patented). (Refer to Reference 3), the structure does not require bolts or the like when the hub B and the pulley A are fitted. However, in this conventional technique, the convex portion of the outer ring and the concave portion of the pulley come into direct contact with each other due to excessive torque or torque fluctuation, and the concave portion of the resin pulley, which is inferior in strength and wear resistance to the outer ring, is abnormally worn. There is a problem of doing it.

<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2001-153152</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2003-56595</text></patcit><patcit num="3"><text>JP-A-2002-364667</text></patcit>

<p> The present invention has been made in view of the above problems, and an object of the present invention is that it does not require bolts or insert fittings, can prevent abnormal wear of the resin pulley, and has high strength between the pulley and the hub. It is to provide a power transmission device which can obtain the coupling structure of.</p>

<p> The present invention provides the power transmission device according to each claim in the claims as a means for solving the above-mentioned problems. The power transmission device according to claim 1 includes a pulley 1, a hub 2 including an inner hub 21, an outer hub 23, and an elastic member 22 for torque transmission, and is provided with an inner peripheral surface side or an outer peripheral surface of the outer hub 23. By engaging the hub-side engaging portion 24 made of an elastic material provided on the side or the inner outer peripheral surface side with the pulley-side engaging portion 12 provided at a position corresponding to the outer hub 23 of the pulley 1. , Forming a torque transmission structure between hub 2 and pulley 1<u style="single">At the same time, a plurality of slits 25 are formed in the hub side engaging portion 24 and the rear side portion of the outer hub 23 at intervals in the circumferential direction.</u>As a result, a high-strength bond between the pulley and the hub can be obtained without the need for bolts, insert fittings, or the like.<u style="single">Further, since a plurality of slits 25 are formed at intervals in the circumferential direction on the hub side engaging portion 24 and the rear side portion of the outer hub 23, for example, a resin having a relatively lower strength than a metal pulley. When it is made of such a material, a reinforcing portion (rib) for ensuring strength may be required. In such a case, if the hub-side engaging portion 24 is formed in a completely annular shape, the ribs of the resin pulley and the hub-side engaging portion 24 may interfere with each other and may not be assembled. By forming the slit 25 in the rear side portion of the hub side engaging portion 24 and the outer hub 23, the problem of assembly can be avoided.</u></p><p> In the power transmission device of claim 2, the pulley 1 is formed of a resin material. As described above, in the present invention, even if the pulley 1 is made of a resin material, since the hub side engaging portion 24 is made of an elastic member, abnormal wear of the pulley can be prevented. The power transmission device according to claim 3 has the outer shapes of the hub-side engaging portion 24 and the pulley-side engaging portion 12 having an uneven shape such as an involute spline or a trochoid, whereby both engaging portions are firmly formed. Engage and provide a strong bond between the pulley and the hub.</p><p> The power transmission device according to claim 4 has a hub-side engaging portion 24 and a pulley-side engaging portion 12 in a fitting structure, whereby the two can be firmly fitted without using bolts or the like. Can be combined. The power transmission device according to claim 5 is provided with the hub-side engaging portion 24 integrally molded or bonded to the outer hub 23. That is, the outer hub 23 and the hub-side engaging portion 24 may be integrally molded by insert molding, or the hub-side engaging portion 24 may be attached to the outer hub 23 by adhesion. The power transmission device according to claim 6 is formed by integrally forming the hub-side engaging portion 24 as a part of the torque transmission elastic member 22, whereby the number of parts can be reduced.</p><p> Claim<u style="single">7</u>The power transmission device of the above substantially tapers at least one of the first or second hub-side engaging portion 24a, 24b of the hub-side engaging portion 24 or the inner or outer surface 11a, 11b of the recess 11 of the pulley 1. It is formed in a shape, which makes it possible to improve the assembling property between the hub 2 and the pulley 1.</p><p> The power transmission device of claim 8 is<u style="single">The maximum width HW of each convex portion 241 of the hub side engaging portion 24 is equal to or greater than the maximum width PW of each convex portion 121 of the pulley side engaging portion 12, whereby the hub side engaging portion is formed. The strength of each of the convex portions 241 of 24 can be improved, and the hub-side engaging portion 24 is not abnormally worn or the convex portion 241 is not destroyed.</u> The power transmission device of claim 9 is<u style="single">A gap g of 0.001 mm or more is provided between the tip portion 241a of the convex portion 241 of the hub side engaging portion 24 and the bottom portion 122a of the concave portion 122 of the pulley side engaging portion 12, which is elastic. It is possible to prevent wear due to the tip portion 241a of the convex portion 241 of the hub side engaging portion 24 made of the member coming into contact with the pulley side engaging portion 12 and sliding.</u></p><p> The power transmission device of claim 10 is<u style="single">R1 part 242d and R2 part 242e are formed on both sides of the bottom part 242a of the recess 242 of the hub side engaging part 24, and the diameter of the R1 part 242d on the rotation direction side is larger than that of the R2 part 242e on the counter-rotation direction side. This makes it possible to alleviate the tensile stress S generated at the root of the convex portion 241 of the hub side engaging portion 24 due to excessive torque, and prevent damage to the convex portion 241. It is possible to improve the durability of the power transmission device.</u> The power transmission device of claim 11 is<u style="single">The side surfaces 241b and 241c of each convex portion 241 of the hub side engaging portion 24 and the side surfaces 122b and 122c of each concave portion 122 of the pulley side engaging portion 12 are in contact with each other to form a torque transmission surface TF, and this torque transmission surface TF is formed. Is arranged on the normal line NL of the pulley 1, so that there is a slight slip during torque transmission at the uneven fitting portion between the hub side engaging portion 24 and the pulley side engaging portion 12. Can be prevented.</u></p><p> The power transmission device of claim 12 is<u style="single">The torque transmission surface TF is deviated from the normal NL by a predetermined angle in the rotation direction of the pulley 1, and even in this case, the occurrence of slight slippage during torque transmission can be sufficiently avoided.</u> The power transmission device of claim 13 is<u style="single">The side surface of each convex portion 121 of the pulley side engaging portion 12 and the side surface of each concave portion 242 of the hub side engaging portion 24 are in contact with each other to form a torque transmission surface TF, and each convex portion of the pulley side engaging portion is formed. The torque transmission surface TF on the rotation side and the torque transmission surface TF on the non-rotation side are made to be substantially parallel. It is possible to prevent the occurrence of slippage.</u></p><p><u style="single">The power transmission device according to claim 14 includes a pulley 1, a hub 2 including an inner hub 21, an outer hub 23, and an elastic member 22 for torque transmission, and is provided with an inner peripheral surface side or an outer peripheral surface of the outer hub 23. By engaging the hub-side engaging portion 24 made of an elastic material provided on the side or the inner outer peripheral surface side with the pulley-side engaging portion 12 provided at a position corresponding to the outer hub 23 of the pulley 1. , A torque transmission structure is formed between the hub 2 and the pulley 1, the outer hub 23 is a metal outer ring 23 separate from the hub side engaging portion 24, and the hub side engaging portion 24 has torque. It is offset toward the root side of the rotating shaft 3 as compared with the elastic member 22 for transmission, and the outer ring 23 made of metal is formed by being pressed from the radial direction, whereby bolts, insert metal fittings, etc. can be pressed. High-strength coupling between the pulley and the hub is obtained without the need. Further, since the outer hub 23 is a metal outer ring 23, the strength can be improved.</u><u style="single">Further, the hub-side engaging portion 24 is offset toward the root side of the rotating shaft 3 as compared with the torque transmission elastic member 22, and the metal outer ring 23 is formed by pressing the metal outer ring 23 from the radial direction. A space S for squeezing the metal outer ring 23 installed on the outer periphery of the transmission elastic member 22 can be secured, a squeezing process can be added to the torque transmission elastic member 22, and the durability of the elastic member 22 can be ensured.</u></p><p><u style="single">The power transmission device according to claim 15 covers the entire surface of the outer ring, which is the outer hub 23, with an elastic material such as rubber or resin that forms the torque transmission elastic member 22 or the hub-side engaging portion 24. As a result, the outer ring has no exposed portion to the outside, it is not necessary to apply paint or the like, and the corrosion resistance and anti-glare property of the outer hub can be improved, and the aesthetic appearance can be further improved. In addition, since the painting process can be eliminated, the environment of the factory is improved and the necessary equipment is not required, so that the cost can be reduced.</u><u style="single">The power transmission device according to claim 16 is provided with a reinforcing portion 23a protruding inside the hub side engaging portion 24 on the outer ring 23 which is an outer hub, whereby the unevenness of the hub side engaging portion is uneven. The strength of the portion can be improved.</u></p><p><u style="single">The power transmission device according to claim 17 includes a pulley 1, a hub 2 including an inner hub 21, an outer hub 23, and an elastic member 22 for torque transmission, and is provided with an inner peripheral surface side or an outer peripheral surface of the outer hub 23. By engaging the hub-side engaging portion 24 made of an elastic material provided on the side or the inner outer peripheral surface side with the pulley-side engaging portion 12 provided at a position corresponding to the outer hub 23 of the pulley 1. , A torque transmission structure is formed between the hub 2 and the pulley 1, the outer hub 23 is an outer ring 23 separate from the hub side engaging portion 24, and the hub side engaging portion 24 is an elastic member for torque transmission. The balancer weight 9 attached to the inner hub 21 or the rotating shaft 3 is arranged on the front side of the hub side engaging portion 24, which is offset to the root side of the rotating shaft 3 as compared with 22. High-strength coupling between the pulley and the hub can be obtained without the need for insert fittings or the like. Further, the balancer weight 9 can be arranged in the space S formed by the offset in this way, and a power transmission device having low noise and low vibration can be obtained.</u><u style="single">The power transmission device of claim 18 is subjected to the same processing as that of claim 15, and the power transmission device of claim 19 is provided with a reinforcing portion 23a as in claim 16 to improve the strength. It is a thing.</u><u style="single">Further, the power transmission device according to claim 20 is formed by making the outer ring metal and pressing it from the radial direction as in claim 14, and the durability of the elastic member 22 can be ensured by drawing.</u></p><p> The power transmission device according to claim 21 is provided with a low coefficient of friction material adhered to, coated, or surface-treated on the surface of the hub-side engaging portion 24, whereby the resistance of the hub-side engaging portion 24 is reduced. The wear resistance can be improved, and a power transmission device having a long life can be obtained.</p>

Hereinafter, the power transmission device according to the embodiment of the present invention will be described with reference to the drawings. The power transmission device of the present invention is suitable for being assembled in a compressor of a vehicle air conditioner. FIG. 1 is a front view of the power transmission device according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. The power transmission device of the present invention is powered between a pulley 1 which is a drive-side rotating member that obtains drive from an engine or a motor and a hub 2 which is a driven-side rotating member fixed to a rotating shaft 3 of a compressor. It transmits torque). The pulley 1 and the hub 2 are provided coaxially.

The pulley 1 is rotatably mounted on a cylindrical portion 41 provided on one end side of the housing 4 of the compressor via a bearing device 5. The pulley 1 is preferably molded of a thermoplastic synthetic resin, but may be formed of a metal material such as iron. When the pulley 1 is made of resin, the pulley 1 and the bearing device 5 are usually integrated by insert molding. A belt (not shown) is wound around the outer peripheral surface of the pulley 1 and is rotated by external power such as an engine or a motor. The bearing device 5 is fitted in the cylindrical portion 41, and the axial movement is prevented by the retaining ring (snap ring) 7 fitted in the groove formed on the outer peripheral surface of the cylindrical portion 41. Further, the housing 4 and the rotating shaft 3 are sealed by the shaft sealing device 6 to prevent the refrigerant, oil, and the like from leaking.

The tip 31 of the rotating shaft 3 of the compressor protrudes from the housing 4, and a threaded portion is formed on the outer peripheral surface of the tip 31, and the cylindrical hub 2 is fixed to the tip 31 by screwing. ing. For fixing the hub 2 to the rotating shaft 3, other fixing methods such as spline engagement and bolt mounting can be appropriately adopted. Reference numeral 8 is a washer.

The hub 2 is composed of an inner hub 21, a damper rubber 22 which is an elastic member for torque transmission, an outer hub 23, and a hub-side engaging portion 24. The inner hub 21 has a cylindrical portion 21a screwed into the tip portion 31 of the rotating shaft 3 and a cylindrical flange portion 21c that protrudes to the front side (left side in FIG. 2) and whose outer peripheral surface is joined to the damper rubber 22. And a disk-shaped intermediate portion 21b that connects the cylindrical portion 21a and the flange portion 21c. A threaded portion is formed on the inner peripheral surface of the cylindrical portion 21a. The inner hub 21 is formed of a metal material such as iron.

The outer hub 23 has a cylindrical shape and is formed of a metal material such as iron like the inner hub 21. The annular damper rubber 22 which is an elastic member for torque transmission is formed of an elastic material such as rubber, is arranged and held between the inner hub 21 and the outer hub 23, and is held on the outer peripheral surface of the flange portion 21c of the inner hub 21 and. It is joined to the inner peripheral surface of the outer hub 23 by means such as adhesion. The damper rubber 22 not only functions as an elastic body for torque transmission, but also functions as a torque damper.

The first hub-side engaging portion 24a is on the inner peripheral surface of the outer hub 23 on the rear side (right side in FIG. 2), and the second hub-side engaging portion 24b is on the outer peripheral surface thereof. It is provided over almost the entire circumference of 23. The first and second hub-side engaging portions 24a and 24b are formed of an elastic material such as rubber or resin, and the outer shape thereof is an uneven shape such as an involute spline or a trochoid. The first and second hub-side engaging portions 24a and 24b are joined to the peripheral surfaces of the outer hub 23 by adhesion or the like, or are integrally formed with the outer hub 23 by insert molding. The hub-side engaging portion 24 may be provided on either the inner peripheral surface or the outer peripheral surface of the outer hub 23, or as shown in FIG. 2, the first and second hub sides. The engaging portions 24a and 24b and the damper rubber 22 may be integrated so that the first and second hub-side engaging portions 24a and 24b wrap the rear side portion of the outer hub 23.

On the other hand, also in the pulley 1, an annular recess 11 for receiving the hub-side engaging portion 24 is formed on the front surface. On the inner surface 11a and the outer surface 11b of the annular recess 11, the first and second pulley-side engaging portions 12a and 12b having an uneven shape such as an involute spline or a trochoid are bonded to each other. It is joined. The pulley-side engaging portion 12 may be attached to either the inner surface 11a or the outer surface 11b of the annular recess 11. Further, the first and second pulley side engaging portions 12a and 12b are also formed of an elastic material such as rubber or resin.

In this way, by fitting the hub-side engaging portion 24 into the annular recess 11 (pulley-side engaging portion 12) of the pulley 1, the first hub-side engaging portion 24a and the first pulley-side engaging portion 12a are formed. The hub 2 and the pulley 1 are connected by engaging the second hub-side engaging portion 24b and the second pulley-side engaging portion 12b.

As described above, in the first embodiment, the coupling between the hub 2 and the pulley 1 fits the hub side engaging portion 24 provided on the hub 2 and the pulley side engaging portion 12 provided on the pulley 1. At the same time, it is carried out by meshing in an uneven shape according to the outer shape thereof, and a power transmission structure having a high transmission force can be formed without the need for bolts or the like.

Further, even if the pulley 1 is formed of a relatively low-strength material such as resin, insert molding of metal fittings or the like is not required, and a low-cost power transmission structure can be obtained. Further, since insert molding is not required, deterioration of the flow of the strength improving material (glass fiber or the like) in insert molding can be avoided, and the strength of the pulley can be increased as intended.

Further, since the outer hub is provided with an engaging portion made of an elastic material, even if the pulley is made of resin, abnormal wear occurs in the fitting portion due to the difference in the strength and wear resistance of the members between the hub and the pulley. Can be prevented.

In the first embodiment, the hub side engaging portion 24 and the outer hub 23 are described as being formed in a continuous annular shape on the entire circumference thereof, but in the present embodiment, FIG. 3 As shown in the perspective view of the hub, the hub-side engaging portion 24 and the rear-side portion of the outer hub 23 may be formed with a plurality of slits 25 at appropriate intervals in the circumferential direction. .. By forming the hub-side engaging portion 24 and the rear-side portion of the outer hub 23 into a plurality of divided shapes in this way, the pulley 1 made of a material such as resin, which is relatively inferior in strength to the metal pulley 1, for example. In the pulley structure in which the strength reinforcing portion (rib) 11c or the like is provided in the radial direction on the bottom surface of the recess 11 of the pulley 1, by making the strength reinforcing portion (rib) 11c correspond to the slit 25, the pulley 1 It is possible to obtain an inexpensive, compact and lightweight power transmission device without worrying about interference between the and hub 2.

FIG. 4 is a cross-sectional view of a pulley showing the second embodiment. In this second embodiment, the outer surface 11b of the recess 11 of the pulley 1 is formed in a substantially tapered shape (inclined) so as to be slightly narrowed from the front side to the rear side. As a result, the assembling property between the hub 2 and the pulley 1 can be improved, and the productivity thereof can be improved. Naturally, the inner surface 11a of the recess 11 of the pulley 1 may be formed in a substantially tapered shape, and further, both the outer surface 11b and the inner surface 11a may be formed in a substantially tapered shape. Further, the outer shape of one or both of the first or second hub-side engaging portions 24a and 24b of the hub-side engaging portion 24 which is not the pulley 1 side but the hub 2 side may be formed in a substantially tapered shape.

FIG. 5 is a cross-sectional view of a main part showing the third embodiment. In the first embodiment, the upper surface of the outer hub 23 is exposed to the outside except for the portion where the second hub side engaging portion 24b is formed, that is, the upper surface of the front side portion is exposed to the outside. If the upper surface of the outer hub 23 is not covered with the torque transmission elastic member 22 as described above, for example, when the outer hub 23 is formed of a metal outer ring 23, the corrosion resistance is improved. There is a problem and it is not aesthetically pleasing. Therefore, in the first embodiment, it is necessary to apply paint to the upper surface of the outer hub 23 exposed to the outside. Therefore, in the third embodiment, the entire surface of the outer hub 23 including the exposed upper surface 23b is covered with the torque transmission elastic member 22. The exposed upper surface 23b may be covered with a thin elastic member 22. Since the other configurations are basically the same as those in the first embodiment, the description thereof will be omitted.

As a result, the corrosion resistance of the outer hub (outer ring) 23 can be improved. Further, since the outer hub 23 has the same color as the torque transmission elastic member 22, for example, if a black elastic material is selected, the antiglare property is good and the sense of quality can be improved. Further, since there is no need for painting and the painting process can be eliminated, the environment of the factory is improved and the necessary equipment is not required, so that the cost can be reduced.

FIG. 6 is a cross-sectional view of a main part showing the fourth embodiment, and FIG. 7 is a front view of the upper half of the power transmission device of the fourth embodiment. In the first to third embodiments, the uneven portion of the hub-side engaging portion 24 is formed of the same elastic material as the torque transmission elastic member 22. Therefore, in high-load operation where the drive torque of the compressor is large, or when the compressor seizes and an excessive torque is generated in the uneven portion of the hub side engaging portion 24, the strength of the uneven portion is increased. , The strength of the adhesive that adheres the hub side engaging part 24 to the inner and outer circumferences of the outer hub (outer ring) 23 is insufficient, and the uneven part and the hub side engaging part 24 are cracked or the uneven part is destroyed. There is a risk of malfunction.

Therefore, in the fourth embodiment, the outer hub (outer ring) 23 is provided with a plurality of reinforcing portions 23a in the normal direction, and the reinforcing portions 23a are embedded in the uneven portions of the second hub-side engaging portion 24b. The reinforcing portion 23a may be formed integrally with the outer hub 23 by cutting out a part of the outer hub 23, or may be formed separately and fixed to the outer hub 23 by welding or the like. In the fourth embodiment, the reinforcing portion 23a is formed so as to face outward in the radial direction, and the second hub-side engaging portion 24b is provided with a plurality of slits 25 in the circumferential direction, and the uneven portion is formed. When divided into a plurality of groups, the reinforcing portions 23a are embedded in the convex portions on both sides of the group as shown in FIG. Since the other configurations are basically the same as those in the first embodiment, the description thereof will be omitted.

In this way, the strength of the uneven portion can be improved by providing the reinforcing portion 23a on the outer hub 23 and embedding the reinforcing portion 23a in the uneven portion of the hub side engaging portion 24. That is, when an excessive torque is generated, the reinforcing portion 23a receives the torque, a large displacement of the elastic member can be suppressed, and damage to the elastic member can be prevented.

FIG. 8 shows the first to third modifications (a), (b), and (c) of the fourth embodiment, respectively. That is, in the first modification of FIG. 8A, the outer hub 23 is provided with the reinforcing portion 23a so as to face inward in the radial direction, and the reinforcing portion 23a is the first hub-side engaging portion. It is embedded in the uneven part of 24a. In the second modification of FIG. 8B, the reinforcing portion 23a provided on the outer hub 23 so as to face outward in the radial direction is provided in the rotational direction in the uneven portion of the second hub-side engaging portion 24b. On the other hand, it is embedded only in the convex portion corresponding to the rear side in the group. In the third modification of FIG. 8 (c), the reinforcing portion 23a provided on the outer hub 23 so as to face outward in the radial direction is rotated in the uneven portion of the second hub-side engaging portion 24b. On the other hand, it is embedded only in the convex portion corresponding to the front side in the group. In any of the above-mentioned first to third modified examples, the strength of the hub-side engaging portion 24 can be improved. In the first modification of FIG. 8A, the outer hub 23 is provided with both the first hub-side engaging portion 24a on the inner peripheral side and the second hub-side engaging portion 24b on the outer peripheral side. The reinforcing portion 23a is embedded in the convex portion of the first hub side engagement, but as shown in FIGS. 9 (a) and 9 (b), the outer hub 23 is provided with the hub side engaging portion 24 only on the inner peripheral side. In the above, a part of the outer ring 23 may be embedded in the hub side engaging portion 24 as the reinforcing portion 23a. Similarly, in the case where the hub side engaging portion 24 is provided only on the outer peripheral side of the outer hub 23, a part of the outer ring 23 may be embedded in the hub side engaging portion as the reinforcing portion 23a. Note that FIG. 9 (a) is a cross-sectional view of the broken line XX ́ in FIG. 9 (b), and the reference numerals shown in FIGS. 9 (a) and 9 (b) have the same configurations as those of the other embodiments. It refers to.

FIG. 10 is a cross-sectional view of a main part showing the fifth embodiment, and FIG. 11 is another embodiment of the present invention for comparison with the fifth embodiment. As shown in the first embodiment of FIG. 2 and the comparative example of FIG. 11, the hub side including the axial center A of the cylindrical elastic portion 22a, which is the main body portion of the torque transmission elastic member 22, and the torque transmission elastic member 22. When the axial center B of the engaging portion 24 is installed with almost no offset, the cylindrical elastic portion 22a cannot be drawn and the durability of the cylindrical elastic portion 22a is significantly reduced, resulting in excessive torque or excessive torque. When a large torque fluctuation is applied, the cylindrical elastic portion 22a of the torque transmission elastic member 22 may be destroyed. Therefore, in the fifth embodiment, the hub-side engaging portion 24 made of the torque transmission elastic member 22 and the cylindrical elastic portion 22a which is also the main body portion of the torque transmission elastic member 22 are provided in an offset shape. Further, this makes it possible to draw the outer peripheral portion (outer peripheral portion of the outer hub) of the cylindrical elastic portion 22a.

That is, in the fifth embodiment, the rear half of the outer hub 23 on the rear side is surrounded by the elastic member 22 for torque transmission, and the outer peripheral surface thereof is made uneven to form the hub side engaging portion 24. Further, the inner peripheral surface of the front half of the outer hub 23 and the outer peripheral surface of the inner hub 21 sandwich the torque transmission elastic member 22 to form the cylindrical elastic portion 22a. The axial center B of the hub-side engaging portion 24 and the axial center A of the cylindrical elastic portion 22a are offset by ε. The offset amount ε is preferably 1/4 or more of the minimum wall thickness t of the cylindrical elastic portion 22a. As a result, a space S is secured in the upper part of the outer hub 23 on the front side so that the outer peripheral portion of the cylindrical elastic portion 22a (the outer peripheral portion of the outer hub 23) can be drawn by the jig shown in FIG. .. This drawing process is carried out for the purpose of improving the durability of the elastic member 22, and it is known that the drawing ratio is about several tens of percent of the outer shape of the cylindrical elastic portion 22a. In FIG. 5, the fact that the stepped portion 23c is formed on the outer hub 23 indicates that this drawing process has been performed. Other configurations are basically the same as those in the first embodiment.

The cross-sectional view of FIG. 10 shows a structure in which the inner hub 21 and the rotating shaft 3 are connected via a torque limiter 26. However, as shown in FIG. 2, the inner hub 21 and the rotating shaft 3 are connected to each other. The present embodiment is also applicable to a structure in which is directly connected.

FIG. 12 shows a vertical cross-sectional view of the power transmission device showing the sixth embodiment. In the sixth embodiment, the space S formed in the fifth embodiment is used so that the weight portion 91 of the balancer weight 9 is housed in the space S. The balancer weight 9 has a substantially disk shape as a whole, and a weight portion 91 is provided in the vicinity of the outer peripheral portion thereof. The balancer weight 9 is fixed to the front side of the inner hub 21 by fixtures 10 such as rivets and bolts, and the weight portion 91 is formed in the space S formed on the front side of the second hub side engaging portion 24b on the front side. It is installed so that it comes to the corresponding position. The balancer weight 9 may be attached by a screw or the like, or by means such as press fitting or caulking, without using the fixture 10. Other configurations are basically the same as those in the first embodiment.

By installing the balancer weight 9 using the space S in this way, it is possible to provide a power transmission device having low noise and low vibration, which can be installed without requiring a significant increase in physique.

FIG. 13 is a front view and a cross-sectional view showing an example of a drawing process of the cylindrical elastic portion 22a. The hub 2 including the outer hub 23, the torque transmission elastic member 22 including the hub side engaging portion 24, the inner hub 21 and the torque limiter 26 is set in the jig 200, and the cylindrical elasticity of the torque transmission elastic member 22 is set. A plurality of cams 201 (16 in FIG. 13) are in contact with the outer periphery of the portion 22a and are arranged in the circumferential direction. The cam 201 has a trapezoidal shape and has a tapered surface on the outside. Corresponding to each of these cams 201, the same number of jigs 202 as the cams 201 are arranged on the outside of the cams 201 in the circumferential direction. The jig 202 is also trapezoidal and has a tapered surface inside. The cam 201, the tapered surface, and the tapered surface of the jig 202 are arranged in contact with each other, and by sliding the jig 202 from right to left in FIG. 15, the cam 201 moves in the direction of reducing the diameter. .. As a result, the cylindrical elastic portion 22a of the torque transmission elastic member 22 is pressed in the radial direction and drawn. Therefore, the outer peripheral portion of the cylindrical elastic portion 22a (the outer peripheral portion of the outer hub) has a substantially hexagonal shape. Here, the durability of the cylindrical elastic portion 22a against distortion in the rotational direction varies depending on the degree of radial distortion of the cylindrical elastic portion 22a, and the more the cylindrical elastic portion 22a is pulled and distorted in the radial direction, the more durable it is against distortion in the rotational direction. Is low, and conversely, the more it is compressed in the radial direction and distorted, the more it rotates. resistance to distortion of the direction is increased. Further, since the cylindrical elastic portion 22a is sandwiched between the outer hub 23 and the inner hub 21 and formed at a high temperature, when the cylindrical elastic portion 22a shrinks as it cools, the adhesive surface between the outer hub 23 and the inner hub 21 becomes the cylindrical elastic portion. 22a will be pulled in the radial direction. That is, as described above, by performing the drawing process, the strain can be relaxed due to the radial tensile stress of the cylindrical elastic portion 22a, and the strain in the rotational direction of the cylindrical elastic portion 22a of the torque transmission elastic member 22 can be relaxed. Durability can be ensured.

14 to 17 are views for explaining the power transmission device of the seventh embodiment. When the hub side engaging portion 24 and the pulley side engaging portion 12 are unevenly fitted and power is transmitted by this uneven fitting portion, the torque due to the compressive force generated when the hub side is operated with an excessive load or the compressor is generated. Due to the fluctuation, there is a problem that the uneven portion of the hub side engaging portion 24 made of the elastic member is abnormally rubbed or the uneven portion is destroyed. Therefore, in the seventh embodiment, the shapes of the uneven portions of the hub-side engaging portion 24 and the pulley-side engaging portion 12 are improved from three viewpoints.

FIG. 14 (a) is a front view of a main part for explaining the power transmission device of the seventh embodiment from the first viewpoint, and FIG. 14 (b) is a main part showing another embodiment for comparison. It is a front view of a part. That is, as shown in FIG. 14B, the maximum width HW of the concave-convex convex portion 241 of the hub-side engaging portion 24 is larger than the maximum width PW of the concave-convex convex portion 121 of the pulley-side engaging portion 12. When it is set to be small, there is a problem in the durability of the hub side engaging portion 24. Therefore, the first viewpoint is to improve the width of the convex portion 241 of the hub side engaging portion 24.

In FIG. 14A, in the uneven fitting between the pulley side engaging portion 12 and the hub side engaging portion 24, the uneven portion of the hub side engaging portion 24 is substantially divided into six, that is, the uneven portion is formed. Is provided with six slits 25, and three convex portions 241 and two concave portions 242 are formed between the slits 25. On the other hand, the pulley side engaging portion 12 is provided with a rib 11c for the slit 25 corresponding to the hub side engaging portion 24, and two convex portions 121 and three concave portions 122 are formed between the ribs 11c. Has been done. In this way, the hub-side engaging portion 24 and the pulley-side engaging portion 12 are unevenly fitted. In the seventh embodiment, the maximum width HW of the convex portion 241 of the hub side engaging portion 24 made of the elastic member is HW PW, that is, with respect to the maximum width PW of the convex portion 121 of the pulley side engaging portion 12. I try to be equal or better. Therefore, the strength of the hub-side engaging portion 24 can be efficiently improved in a physique in which the width of the elastic member is limited.

FIG. 15 (a) is a front view of a main part for explaining the power transmission device of the seventh embodiment from the second viewpoint, and FIG. 15 (b) is a main part showing another embodiment for comparison. It is a front view of a part. That is, as shown in FIG. 15 (b), when the tip portion 241a of the convex portion 241 of the hub side engaging portion 24 and the bottom portion 122a of the concave portion 122 of the pulley side engaging portion 12 are in contact with each other, they slide. Therefore, the convex portion 241 of the hub-side engaging portion 24 made of the elastic member is worn. Generally, the hub 2 and the pulley 1 generate a minute displacement when an excessive torque is transmitted, but when they are in contact with each other as described above, they slide, so that the convex portion 241 of the elastic member Wear out.

Therefore, in the seventh embodiment, as shown in FIG. 15A, between the tip portion 241a of the convex portion 241 of the hub side engaging portion 24 and the bottom portion 122a of the concave portion 122 of the pulley side engaging portion 12. , A gap g of at least 0.001 mm is provided. In this way, by providing a gap g between the tip portion 241a of the convex portion 241 of the hub side engaging portion 24 made of the elastic member and the bottom portion 122a of the concave portion 122 of the pulley side engaging portion 12, contact between the two. It is designed to prevent wear due to.

16 and 17 (a) are front views of the main parts for explaining the power transmission device of the seventh embodiment from the third viewpoint, and FIG. 17 (b) is another embodiment for comparison. It is a front view of the main part which shows. That is, as shown in FIG. 17 (b), a large tensile stress F is generated in the R1 portion 242d, which is the corner portion on the rotation direction side of the bottom portion 242 of the recess 242 of the hub side engaging portion 24, due to excessive torque. Therefore, if the radius of curvature r of the R1 portion 242d is small, it may not be able to withstand this stress F and may be damaged.

Therefore, in the seventh embodiment, as shown in FIGS. 16 and 17 (a), of the R1 portion 242d and the R2 portion 242e provided on both sides of the bottom portion 242a of the recess 242 of the hub side engaging portion 24. , The radius of curvature r of the R1 part 242b located on the rotation direction side (front side) is larger than the curvature radius r of the R2 part 242e located on the opposite rotation direction side (rear side). As a result, the tensile stress S generated in the R1 portion (corner portion) 242d (root portion of the convex portion 241) of the bottom portion 242a of the concave portion 242 of the hub side engaging portion 24 due to excessive torque is relaxed, and the durability of the power transmission device is increased. The sex can be improved. If the radius of curvature r of the R1 portion 242d and the R2 portion 242e on both the rotation direction side and the counter-rotation direction side is increased, the width of the convex portion 121 of the pulley side engaging portion 12 becomes larger, and the overall large pulley In the seventh embodiment, it is preferable to increase the radius of curvature r of only the R1 portion 242d on the rotation direction side because there is a risk of the diameter becoming large. Therefore, the recess 242 of the hub-side engaging portion 24 is asymmetrical between the rotation direction side and the counter-rotation direction side.

As described above, in the seventh embodiment, (1) the maximum width HW of the convex portion 241 of the hub side engaging portion 24 is equal to or larger than the maximum width PW of the convex portion 121 of the pulley side engaging portion 12. By doing so, the strength of the convex portion 241 of the hub side engaging portion 24 can be improved, and (2) the tip portion 241a of the convex portion 241 of the hub side engaging portion 24 and the bottom of the concave portion 122 of the pulley side engaging portion 12 A gap g is provided between the portion 122a to prevent the convex portion 241 of the hub-side engaging portion 24 from being worn, and (3) the concave portion 242 of the hub-side engaging portion 24 and the corners on both sides of the bottom portion 242a. Of the R1 part 242d and R2 part 242e, the tensile stress generated in the R1 part 242d by making the radius of curvature r of the R1 part 242d on the rotation direction side larger than the radius of curvature r of the R2 part 242e on the opposite rotation direction side. The durability of the power transmission device is improved by relaxing F and improving the shape of the uneven portion of the uneven fitting portion.

18 to 19 (a) are front views of a main part for explaining the power transmission device of the eighth embodiment. In the eighth embodiment, the positions of the transmission surfaces of the concave-convex fitting portions of the hub-side engaging portion 24 and the pulley-side engaging portion 12 are improved. That is, as shown in FIG. 19B, when the uneven portion of the pulley side engaging portion 12 of the pulley 1 and the hub side engaging portion 24 of the hub 2 has an uneven shape having a spline profile, the pulley side. The side surfaces 122b, 122c of the concave portion 122 of the engaging portion 12 and the side surfaces 241b, 241c of the convex portion 241 of the hub side engaging portion 24 are in contact with each other for power transmission to form a torque transmission surface TF. , This torque transmission surface TF is formed at a position deviated by an α angle with respect to the rotation direction (normal direction). Therefore, when an excessive torque is generated or a torque fluctuation occurs, the uneven fitting portion is twisted by the pulley 1 and the rotating shaft 3 of the compressor, as shown in FIG. 19 (b). There is a risk that the slip SL shown will occur and the torque transmission surface TF of the uneven portion of the hub side engaging portion 24 made of the elastic member will be abnormally worn.

Therefore, in the eighth embodiment, the position of the torque transmission surface TF is improved. As shown in FIG. 18 (a), the side surfaces 241b and 241c of the convex portion 241 of the hub side engaging portion 24 (the slit 25 is regarded as the concave portion of the hub side engaging portion 24) and the pulley side engaging portion 12 (the rib 11c are The side surfaces 122b and 122c of the recess 122 of the recess 122 (considered to be the convex portion of the pulley-side engaging portion 12) are in contact with each other to form a torque transmission surface TF. In the eighth embodiment, the torque transmission surface TF is arranged on the normal NL of the pulley 1 (in other words, a straight line orthogonal to the circumference of an arbitrary circle centered on the rotation axis in the radial direction). , The uneven portion of the hub side engaging portion 24 and the pulley side engaging portion 12 is formed. FIG. 18B is a front view of the uneven portion of the pulley side engaging portion 12. The side surfaces 121b and 121c of the convex portion 121 (also the side surfaces 122b and 122c of the concave portion 122) of the pulley side engaging portion 12 (including the rib 11c) are torque transmission surface TFs, and all of these torque transmission surface TFs are pulleys. It is located on the normal NL of 1. FIG. 18C is a front view of the uneven portion of the hub side engaging portion 24. The side surfaces 241b and 241c of the convex portion 241 (also the side surfaces 242b and 242c of the concave portion 242) of the hub side engaging portion 24 (including the slit 25) are torque transmission surface TFs, and all of these torque transmission surface TFs are pulleys. It is located on the normal NL of 1.

FIG. 19A shows a modified example of the eighth embodiment, and the torque transmission surface TF may be shifted by a predetermined angle β in the rotation direction with reference to the normal NL of the pulley 1. There is no problem even if this predetermined angle β is shifted to about 10 degrees in the rotation direction or about 45 degrees in the counter-rotation direction (-45 degrees from the rotation direction) with respect to the normal NL.

Further, in the eighth embodiment, even if the two torque transmission surfaces TF formed by the rotation side side surface 121b and the counter-rotation side side surface 121c of the convex portion 121 of the pulley side engagement portion 12 are substantially parallel. Good (see Figure 18 (b)). In this case, the side surface 11c on the rotation side of the rib 11c₁And the side surface on the opposite side 11c₂The two torque transmission surfaces TF formed by and may be substantially parallel. This means that when viewed from the hub 2 side, the two torque transmission surfaces TF formed by the rotation side side surface 242b and the counter-rotation side side surface 242c of the recess 242 of the hub side engaging portion 24 are substantially parallel. It means that it may be (see Fig. 18 (c)). Similarly, it means that the two torque transmission surfaces TF formed by the rotation side side surface and the anti-rotation side side surface of the slit 25 may be substantially parallel.

As described above, in the eighth embodiment, the torque transmission surface TF, which is a surface for transmitting torque formed by the uneven portion of the pulley side engaging portion 12 and the hub side engaging portion 24, is arranged on the normal NL. It is possible to suppress the occurrence of minute slip SL in the uneven portion due to excessive torque operation or torque fluctuation, and to avoid abnormal wear of the uneven portion.

FIG. 20 is a front view of a main part for explaining the power transmission device of the ninth embodiment. The present invention proposes a power transmission structure between the pulley 1 and the hub 2 by unevenly fitting the pulley-side engaging portion 12 of the pulley 1 and the hub-side engaging portion 24 of the hub 2. When operated under a load or due to torque fluctuations due to the compressive force generated by the compressor, the uneven portion of the hub-side engaging portion 24 made of an elastic member may be abnormally worn or the concave portion may be destroyed. Therefore, in the ninth embodiment, a material having excellent wear resistance (low coefficient of friction material) is formed on the surface of the uneven portion of the hub-side engaging portion 24 made of an elastic member.<u style="single">27</u>Contact<u style="single">Arrival</u>The wear resistance of the hub-side engaging portion 24 has been improved by performing coating or surface treatment.

That is, as shown in FIG. 20, for example, the uneven portion of the hub-side engaging portion 24 is roughly divided into six, that is, six slits 25 are provided, and two convex portions 241 and three concave portions 242 are provided between the slits 25. It is formed. FIG. 20 shows only the uneven portion sandwiched between the slits 25. On the other hand, the pulley side engaging portion 12 is provided with a rib 11c for the slit 25 corresponding to the hub side engaging portion 24, and three convex portions 121 and two concave portions 122 are provided between the ribs 11c. It is formed. In this way, the hub-side engaging portion 24 and the pulley-side engaging portion 12 are unevenly fitted to each other, and power is transmitted. Since an excessive torque is applied to this uneven portion, the torque transmission surface TF (side surface 241b, 241c of the convex portion 241) of the uneven portion of the hub side engaging portion 24 made of an elastic member, the bottom portion 242a of the concave portion 242, and the convex portion are particularly convex. A material with excellent wear resistance (low coefficient of friction material) on the surface of the uneven portion of the hub side engaging portion 24 in order to prevent the tip portion 241a of the portion 241 from being abnormally worn.<u style="single">27</u>Adhesive or material with excellent wear resistance<u style="single">27</u>The wear resistance of the surface of the uneven portion is improved by coating the surface of the uneven portion or performing a surface treatment.

Material with excellent wear resistance<u style="single">27</u>Examples include resin films typified by crosslinked ethylene tetrafluoride (PTFE) and polyamide films, such as woven fabrics woven from materials such as Nomex (trademark), Cornex (trademark), and Kevlar (trademark). Cloth or non-woven fabric, metal flakes and the like are suitable. As the coating, those containing a fluorine compound such as graphite, molybdenum disulfide, ethylene tetrafluoride (PTFE), and PFA as a low coefficient of friction material are suitable. As surface treatment, chlorine treatment is also possible for uneven shapes consisting of chlorinated butyl rubber, which is a material containing double bonds, elastic members of ethylene / propylene / diene copolymer, and elastic members of acrylic / ethylene copolymer. It is valid.

<figref num="1">It is a front view of the power transmission device of 1st Embodiment of this invention.</figref><figref num="2">It is sectional drawing in the AA line of FIG.</figref><figref num="3">It is a perspective view of the hub of 1st Embodiment.</figref><figref num="4">It is sectional drawing of the pulley in 2nd Embodiment.</figref><figref num="5">It is sectional drawing of the main part of the hub of 3rd Embodiment.</figref><figref num="6">It is sectional drawing of the main part of the hub of 4th Embodiment.</figref><figref num="7">It is a front view of the upper half of the power transmission device of 4th Embodiment.</figref><figref num="8">It is a figure which shows the modification (a), (b), (c) of the 4th embodiment.</figref><figref num="9">It is (a) sectional view and (b) front view of the modification of 4th Embodiment.</figref><figref num="10">It is the upper half sectional view of the power transmission device of 5th Embodiment.</figref><figref num="11">FIG. 5 is an upper half cross-sectional view showing another embodiment for comparison with the fifth embodiment.</figref><figref num="12">It is sectional drawing of the power transmission device of 6th Embodiment.</figref><figref num="13">It is a front view (a) and a sectional view (b) which show the process example of drawing processing.</figref><figref num="14">(a) is a front view of a main part for explaining the power transmission device of the seventh embodiment, and (b) is a front view of the main part showing another embodiment for comparison.</figref><figref num="15">(a) is a front view of a main part for explaining the power transmission device of the seventh embodiment, and (b) is a front view of the main part showing another embodiment for comparison.</figref><figref num="16">It is a front view of the main part explaining the power transmission device of 7th Embodiment.</figref><figref num="17">(a) is a front view of the main part of the hub-side engaging portion in the seventh embodiment, and (b) is a main part front view of the hub-side engaging portion in another embodiment for comparison.</figref><figref num="18">(a) is a front view of a main part for explaining the power transmission device of the eighth embodiment, (b) is a front view of the main part of the engagement part on the pulley side in the eighth embodiment, and (c) is a front view of the main part. , 8 is a front view of a main part of the hub side engaging portion in the eighth embodiment.</figref><figref num="19">(a) is a front view of the main part of the power transmission device in the modified example of the eighth embodiment, and (b) is a front view of the main part showing another embodiment for comparison.</figref><figref num="20">It is a front view of the main part explaining the power transmission device of 9th Embodiment.</figref><figref num="21">Sectional views (a), (b), and (c) of the three conventional power transmission devices are shown.</figref>

Code description

1 pulley 11 Recess 11a inner surface 11b outer surface 11c rib 12a First pulley side engaging part 12b 2nd pulley side engaging part 121 Convex part 122 recess 2 hub 21 Inner hub 21a Cylindrical part 21b middle part 21c Flange 22 Damper rubber (elastic member for torque transmission) 22a Cylindrical elastic part 23 Outer hub 23a Reinforcement 23b Exposed top surface 23c Step 24 Hub side engaging part 24a 1st hub side engaging part 24b 2nd hub side engagement 241 Convex part 241a tip 242 Recess 242a bottom part 25 slits 26 <u style="single">Torque limiter</u> 3 axis of rotation 31 tip 4 housing 41 Cylindrical part 5 Bearing equipment 9 Balancer Wait A Axial center of the elastic part of the cylinder B Axial center of hub side engaging part F tensile stress SL slip g gap NL normal TF torque transmission surface