Flexible coupling

Abstract

To provide a high-reliability flexible coupling capable of enhancing durability performance and vibration absorption performance during torque fluctuation, and capable of easily controlling the vibration absorption performance during the torque fluctuation.SOLUTION: A flexible coupling 1 couples a drive-side rotational shaft and a driven-side rotational shaft, the flexible coupling 1 comprising: a plurality of cylindrical members 2 that is arranged at a predetermined interval G in a circumferential direction Dc, with an axial line of each of the drive-side and driven-side rotational shafts as a center C, and into which a connector of each rotational shaft is inserted and fixed; metal members 4 that are arranged between adjacent cylindrical members 2 in the circumferential direction Dc, and connect the adjacent cylindrical members 2 to each other, thereby transmitting torque between the rotational shafts; and an annular elastic body 6 in which the respective cylindrical members 2 and the respective metal members 4 are embedded.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a flexible coupling, and more particularly to a flexible coupling that connects a driving-side rotating shaft and a driven-side rotating shaft.

Background Art

[0002] Patent Document 1 discloses a flexible coupling that connects a driving-side rotating shaft and a driven-side rotating shaft. This flexible coupling includes a plurality of wire-wound members arranged at a predetermined interval in the circumferential direction around the axis of each rotating shaft, a torque transmission wire wound around adjacent wire-wound members in the circumferential direction, and an annular elastic body in which the wire-wound members and the torque transmission wire are embedded.

[0003] The above flexible coupling is premised on being incorporated into a vehicle power transmission device having a hypoid gear. In a hypoid gear, the gear meshing transmission error is larger during negative torque transmission than during positive torque transmission, and the noise and vibration (NV) generated when transmitting torque are also likely to increase. Therefore, in the above flexible coupling, the torque transmission wire is composed of a positive torque transmission wire responsible for transmitting positive torque and a negative torque transmission wire responsible for transmitting negative torque.

[0004] The total cross-sectional area of the negative torque transmission wires is set to 1 / 2 of that of the positive torque transmission wire. Thereby, the peak value of NV generated when the vehicle power transmission device transmits negative torque can be reduced, and the excessive specification of the strength of the negative torque transmission wire in the flexible coupling can be relaxed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Since the torque transmission wire material is not a rigid body but is formed from fibers made of a polymer material such as polyester or nylon, etc., its tensile strength has a limit. Therefore, when the transmitted torque is large, the above torque transmission wire material may break, and its durability performance is inferior. Further, since the above torque transmission wire material is a fiber, its durability performance and vibration absorption performance during torque fluctuation are greatly affected by the characteristics of the material, and also, the elongation rate and recovery rate when it is stretched vary greatly depending on the characteristics of the material. Therefore, when using the above torque transmission wire material, the upper limit value of the allowable torque fluctuation has to be set low, and it is difficult to control the vibration absorption performance during torque fluctuation.

[0007] The present invention has been made in view of such problems, and an object thereof is to provide a highly reliable flexible coupling that can enhance the durability performance and vibration absorption performance during torque fluctuation, and can easily control the vibration absorption performance during torque fluctuation.

Means for Solving the Problems

[0008] To achieve the above object, the flexible coupling of the present invention is a flexible coupling that connects a driving-side rotating shaft and a driven-side rotating shaft, and is arranged with a predetermined interval in the circumferential direction centered on the axis of each of the driving-side and driven-side rotating shafts, and a plurality of cylindrical members into which connectors of each rotating shaft are inserted and fixed, and metal members that are respectively arranged between adjacent cylindrical members in the circumferential direction and transmit the torque between each rotating shaft by connecting the adjacent cylindrical members to each other, and an annular elastic body in which each cylindrical member and each metal member are embedded.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a highly reliable flexible coupling that can enhance the durability performance and vibration absorption performance during torque fluctuation, and can easily control the vibration absorption performance during torque fluctuation.

Brief Description of the Drawings

[0010] [Figure 1] It is a perspective view of a flexible coupling according to an embodiment of the present invention. [Diagram 2] It is a transparent view of FIG. 1. [Figure 3] It is a partial cross-sectional view of a cylindrical member. [Figure 4] It is a plan view of a metal member. [Figure 5] It is a graph showing an example of the change in transmission torque with respect to the rotational angle difference between the driving-side rotating shaft and the driven-side rotating shaft. [Figure 6] It is a plan view of a metal member according to a modification. [Figure 7] It is a transparent view of a flexible coupling according to a modification. [Figure 8] It is a perspective view of a metal member according to another modification.

Mode for Carrying Out the Invention

[0011] Hereinafter, a flexible coupling according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a perspective view of a flexible coupling 1 according to the embodiment, and FIG. 2 shows a transparent view of FIG. 1. The flexible coupling 1 is a joint that connects a driving-side rotating shaft and a driven-side rotating shaft (not shown), and includes a plurality of cylindrical members 2, a plurality of metal members 4, and an annular elastic body 6.

[0012] FIG. 3 shows a partial cross-sectional view of the cylindrical member 2. Since FIG. 3 is in a slightly different form from FIGS. 1 and 2, the difference will be described later. The cylindrical members 2 are arranged at a predetermined interval G in the circumferential direction Dc centered on the axis C of the above-described driving-side and driven-side rotating shafts, and connectors (not shown) of the above-described rotating shafts are inserted and fixed to each cylindrical member 2. Specifically, the cylindrical member 2 is composed of a sleeve 8 and a collar 10. It is preferable that both the sleeve 8 and the collar 10 are made of metal.

[0013] The sleeve 8 has a stepped portion 8b whose outer peripheral surface 8a is reduced in diameter, and a small-diameter portion 8c whose diameter is further reduced from the stepped portion 8b. The collar 10 is press-fitted and fixed to the small-diameter portion 8c of the sleeve 8, and a connection portion 16 (described later) of the metal member 4 is wound around and fixed to the stepped portion 8b. Connectors for the respective rotating shafts described above are inserted into and fixed to the sleeve 8. In the case of this embodiment, six cylindrical members 2 are arranged, and three connectors of the driving-side rotating shaft are respectively inserted into and fixed to the sleeves 8 of the three cylindrical members 2 arranged at intervals of one in the circumferential direction Dc with bolts or the like.

[0014] On the other hand, three connectors of the driven-side rotating shaft are respectively inserted into and fixed to the remaining three cylindrical members 2 with bolts or the like. Thereby, the rotational driving force of the driving-side rotating shaft is transmitted to the driven-side rotating shaft via the flexible coupling 1. Note that since the range of the stepped portion 8b shown in FIGS. 1 and 2 is ensured to be larger than that in the case of FIG. 3, in the case shown in FIGS. 1 and 2, different from the case of FIG. 3, the connection portions 16 of the metal member 4 adjacent to the stepped portion 8b can be arranged vertically side by side.

[0015] FIG. 4 shows a plan view of the metal member 4. The metal member 4 is a torque transmission member that is respectively arranged between adjacent cylindrical members 2 in the circumferential direction Dc, connects the adjacent cylindrical members 2 to each other, and enables torque transmission between the respective rotating shafts described above. Specifically, the metal member 4 is a leaf spring 12 having a predetermined width W (see FIGS. 2 and 3) in the axial direction Da of each rotating shaft, and the leaf spring 12 has a curved shape in the circumferential direction Dc.

[0016] In the case of this embodiment, six leaf springs 12 are arranged, and each leaf spring 12 has a spring portion 14 positioned between adjacent cylindrical members 2 and a connection portion 16 connected to each sleeve 8. The connection portion 16 shown in FIG. 4 is formed in a cylindrical shape by winding the end portion of the spring portion 14 around the collar 10. Each spring portion 14 has a curved shape that protrudes outward in the radial direction Dr passing through the center C of the axis along the circumferential direction Dc. Further, as also shown in FIG. 2, the boundary 18 between the spring portion 14 and the connection portion 16 is positioned on the outer peripheral surface 8a on the outer side in the radial direction Dr.

[0017] The annular elastic body 6 is formed in an annular shape with a rectangular cross-section from, for example, a rubber material, and each cylindrical member 2 and each metal member 4 are embedded by vulcanization molding of the rubber material. In the case shown in FIGS. 1 and 2, the outer peripheral surface 6a of the annular elastic body 6 forms an arc shape in the circumferential direction Dc, while the inner peripheral surface 6b is thinned at the portion between the cylindrical members 2 and is formed in a wave shape in the circumferential direction Dc. Note that the annular elastic body 6 is not limited to the above shape, and may have a shape having a large number of annular grooves 20 at predetermined intervals along the circumferential direction Dc as shown in FIG. 3. Each annular groove 20 functions as a relief for the rubber material when the annular elastic body 6 is deformed. As a result, the deformation of the annular elastic body 6 is smoothly performed, and thus the vibration absorption performance of the annular elastic body 6 is further enhanced.

[0018] FIG. 5 shows a graph representing an example of the change in the transmission torque with respect to the rotational angle difference between the driving-side rotating shaft and the driven-side rotating shaft. When the rotational angle difference between the driving-side rotating shaft and the driven-side rotating shaft increases to about 5 deg or more, the increasing mode of the torque transmitted from the driving-side rotating shaft to the driven-side rotating shaft changes from a proportional function mode to an exponential function mode. This is due to the use of the metal member 4 as the torque transmission member. From this experiment, it was found that the responsiveness of the vibration absorption performance of the flexible coupling 1 of the present embodiment is significantly enhanced.

[0019] As described above, the flexible coupling 1 of the present embodiment includes the above-described cylindrical members 2, metal members 4, and an annular elastic body 6 in which the cylindrical members 2 and the metal members 4 are embedded. As a result, since the torque transmission member is the metal member 4, the tensile strength of the torque transmission member can be increased as compared with the case of a wire made of fibers as in the prior art, and thus the durability performance of the flexible coupling 1 can be enhanced. Further, since it is not necessary to consider the characteristics of the elongation rate and the recovery rate when pulled like a wire, the vibration absorption performance during torque fluctuation can be surely enhanced, and the vibration absorption performance during torque fluctuation can be easily controlled.

[0020] In addition, since the metal member 4 is the leaf spring 12 having a predetermined width W in the axial direction Da, the rigidity of the flexible coupling 1, particularly in the axial direction Da, can be increased. As a result, when receiving torque fluctuations, the load in the axial direction Da can be effectively absorbed, so that the vibration absorption performance during torque fluctuations can be further enhanced. Further, since the leaf spring 12 has a shape curved in the circumferential direction Dc, torque transmission in the leaf spring 12 can be smoothly performed along the annular elastic body 6. Therefore, the vibration absorption performance during torque fluctuations can be further enhanced.

[0021] This concludes the description of the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the flexible coupling 1 of the above embodiment uses the metal member 4 as a torque transmission member, and exhibits the above-described advantageous effects as compared with the case where the torque transmission member is a wire made of fibers. Therefore, the metal member 4 can adopt a shape other than the above-described shape.

[0022] Specifically, as shown in FIG. 6, the leaf spring 12 as the metal member 4 may have one or more bellows portions 22 that are concave and convex in the circumferential direction Dc. Thereby, vibrations during torque fluctuations can be more suitably absorbed in the bellows portion 22, so that the vibration absorption performance during torque fluctuations can be further enhanced. Further, as shown in FIG. 7, the boundary 18 between the spring portion 14 and the connecting portion 16 of the metal member 4 may be positioned on the inner outer peripheral surface 8a in the radial direction Dr of the flexible coupling 1.

[0023] Also, although not shown, the boundary 18 between the spring portion 14 and the connecting portion 16 may be positioned on the outer peripheral surface 8a around the middle between the case of FIG. 2 and the case of FIG. 7. Further, the connecting portion 16 of the metal member 4 may be a member processed into a cylindrical shape in advance, rather than being formed by winding the end portion of the spring portion 14 around the sleeve 8. In this case, the metal member 4 is fixed to the sleeve 8 by fitting the cylindrical connecting portion 16 into the stepped portion 8b of the sleeve 8, and the spring portion 14 is fixed to the connecting portion 16 by welding or the like.

[0024] By adopting such a form, as shown in FIG. 3, the connection portion 16 of the adjacent metal members 4 can be shared. Further, since it is sufficient to secure the range of the stepped portion 8b formed on the sleeve 8 only within the range of one connection portion 16, the cylindrical member 2 can be made more compact. Furthermore, the cylindrical member 2 does not necessarily have to be composed of the sleeve 8 and the collar 10 as long as it can connect the metal members 4, and it may be formed as an integral member.

[0025] Also, as shown in FIG. 8, each spring portion 14 may be curved in a direction opposite to the direction along the circumferential direction Dc, in other words, may have a curved shape convex toward the inside in the radial direction Dr. Furthermore, as long as the metal member 4 functions as a torque transmission member that exhibits the above-described advantageous effects, it does not necessarily have to be the leaf spring 12, and it may be a metal wire bundle or the like. The modified examples shown in FIGS. 6 to 8 described above are changes within the scope that does not depart from the gist of the present invention, and of course exhibit the same advantageous effects as in the case of the above-described embodiment.

Description of Reference Numerals

[0026] 1 Flexible coupling 2 Cylindrical member 4 Metal member 6 Annular elastic body 12 Leaf spring 22 Bellows C Center Da Axial direction Dc Circumferential direction G Gap W Width

Claims

1. A flexible coupling that connects a drive-side rotating shaft and a driven-side rotating shaft, a plurality of cylindrical members arranged at predetermined intervals in a circumferential direction around the axis of each of the driving and driven rotating shafts, and into which connectors of each of the rotating shafts are inserted and fixed; metal members that are disposed between the cylindrical members that are adjacent in the circumferential direction and connect the adjacent cylindrical members to each other, thereby transmitting torque between the rotating shafts; an annular elastic body in which the cylindrical members and the metal members are embedded; A flexible coupling comprising:

2. 2. The flexible coupling according to claim 1, wherein the metal member is a leaf spring having a predetermined width in the axial direction of each of the rotary shafts.

3. The flexible coupling according to claim 2 , wherein the leaf spring has a curved shape in the circumferential direction.

4. The flexible coupling according to claim 3 , wherein the leaf spring has a bellows portion that is uneven in the circumferential direction.

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