JPH0235070Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a damper structure, and more particularly to a damper structure between a shaft and a gear.

[Prior art]

In a power transmission mechanism that transmits power to a shaft via a gear, a torsion spring such as a coil spring is interposed between the gear and the shaft, and the torsion spring absorbs shocks and vibrations applied to the gear. It is already well known that torsional vibration occurs in the shaft, and that there are methods that suppress the occurrence of gear noise. Furthermore, it is well known that some of the above configurations use a plurality of torsion springs in consideration of the durability of the torsion springs. FIG. 5 and FIG. 6 are specific examples thereof. A gear B is loosely fitted to the shaft A, and the gear B is disposed between a hub C fixed to the shaft A and a plate D. Furthermore, three long holes E are formed in the gear B, and pins F that connect the hub C and the plate D pass through each of these long holes E.
Additionally, coil springs G as torsion springs are interposed at three locations between gear B, hub C, and plate D, and these coil springs G and the aforementioned elongated holes E are connected to gear B, respectively. They are arranged side by side on the same circumference on the top.

Now, when an external force is applied to gear B as shown by arrow Z, this force is transmitted from gear B to hub C via coil spring G, and further transmitted from hub C to shaft A. At this time, if the external force is shocking or excessive, the external force is absorbed by the coil spring G, and the adverse effect on the shaft A is suppressed.

By the way, when trying to obtain a damper structure in which the displacement angle of the gear with respect to the shaft is large, the stroke of the coil spring, in other words, the spring length, naturally needs to be long. However, when trying to arrange a coil spring with a long spring length linearly inside a gear as described above, the installation space for the spring is limited by the gear diameter, and the usable coil spring length, in other words, is limited. The displacement angle of the gear was limited. Furthermore, if the coil spring is curved along the circumference of the gear and placed inside the gear,
Since an irregular force is applied to the coil spring, normal spring characteristics of the coil spring cannot be obtained, which may impede the damper effect.

[Purpose of invention]

In view of the above-mentioned circumstances, an object of the present invention is to provide a damper structure that can provide an effective damper action even in a range where the displacement angle of the gear is large compared to conventional damper structures.

[Structure of the idea]

Therefore, in the present invention, the plate portion of the intermediate member consisting of a cylindrical portion and a plate portion is disposed between a hub fixed to the shaft and a gear rotatably provided to the shaft. A first torsion spring and a second torsion spring are provided between the gear and the plate portion and the hub, respectively.
The above objective is achieved by interposing a torsion spring.

〔Example〕

Hereinafter, the configuration of the present invention will be explained in detail based on the drawings showing one embodiment.

As shown in FIGS. 1 to 4, a sleeve 2 is fitted onto the shaft 1, and a disc-shaped hub 3 is provided upright on the sleeve 2. As shown in FIGS. Further, the hub 3 is formed with a curved elongated hole 4 extending in the circumferential direction thereof. An intermediate member 5 is disposed on the right side of the hub 3 in the figure. This intermediate member 5 is
It is composed of a cylindrical portion 5a that loosely fits into the sleeve 2, and a plate portion 5b that projects radially outward from the left end of the cylindrical portion 5a.The intermediate member 5 is connected to the shaft 1 through the sleeve 2. Supported.

A gear 6 is disposed on the right side of the intermediate member 5 in the figure. This gear 6 is loosely fitted into the cylindrical portion 5a of the intermediate member 5, and the gear 6 is loosely fitted into the cylindrical portion 5a of the intermediate member 5.
and is supported on the shaft 1 via the sleeve 2.

Here, as is clear from the figure, the hub 3,
The plate portion 5b and the gear 6 are arranged in parallel with each other, and the plate portion 5b is arranged between the hub 3 and the gear 6. Similar to the hub 3, this gear 6 also has a curved elongated hole 7 extending in the circumferential direction.
is formed. On the other hand, a hub side plate 8 is located on the left side of the hub 3 and on the right side of the gear 6 in the figure.
and the gear side plate 9 are respectively connected to the shaft 1.
The gear side plate 8 and the hub side plate 9 are connected by a pin 10. A spacer 11 is fitted to the pin 10, and the pin 10 is connected to the elongated hole 4 of the hub 3 and the elongated hole 7 of the gear 6 via the spacer 11.
is inserted into. Further, the pin 10 and the spacer 11 pass through the plate portion 5b of the intermediate member 5, and thus the plate portion 5b of the intermediate member 5, the hub side plate 8, and the gear side plate 9.
It is assembled integrally with. On the other hand, a coil spring 12 as a first torsion spring and a coil spring 13 as a second torsion spring are arranged in the lower part of the figure, in other words, in a part sandwiching the shaft 1 and facing the pin 10, etc. has been done.

The coil spring 12 is connected to the gear 6 and the intermediate member 5.
The coil spring 13 is interposed between the plate portion 5a and the gear side plate 9.
is interposed between the hub 3, the plate portion 5a of the intermediate member 5, and the hub-side plate 8.

When the gear 6 is in its initial state, the long hole 4 formed in the hub 3 and the long hole 7 formed in the gear 6 are located so as to almost overlap each other, as shown in FIG. It occupies approximately the center of long holes 4 and 7.

When an external force is applied to the gear 6 in the direction of arrow Z, the coil spring 12 is compressed by the relative movement of the intermediate plate 5 and the gear side plate 9 and the gear 6 at a displacement angle α, as shown in FIG. , the coil spring 13 due to the relative movement of the intermediate plate 5 and the hub side plate 8, and the hub 3 at a displacement angle β.
is compressed. At this time, the external force applied to the gear 6 is transmitted from the gear 6 to the intermediate plate 5 via the coil spring 12, and then transmitted from the intermediate plate 5 to the hub 3 via the coil spring 13, and further from the hub 3 to the sleeve. 2 to the shaft 1.

In the damper structure having the above configuration, the limit of the angular displacement of the gear 6 with respect to the shaft 1 is from the initial position shown in FIG. and the angle α′ of
The sum of the angle β' from the initial position until the spacer 11 abuts one end 4a of the elongated hole 4 on the hub 3;
θ′. It is clear from the figure that the range of the above angular displacement can be almost doubled compared to the conventional damper structure in which the long holes are not arranged in parallel in the axial direction of the shaft.

Furthermore, even when the present invention is implemented without using the above-mentioned engagement means consisting of the elongated holes 4, 7, pin 10, etc., the range of angular displacement of the gear with respect to the shaft is limited to the compression limit of each of both coil springs. Since it is the sum of the angular displacements up to 100 degrees, it goes without saying that the displacement angle can be almost twice that of the conventional one.

In this example, the coil springs 12 and 13 are arranged so as to overlap in the axial direction of the shaft 1 in the initial state of the gear 6 shown in FIG.
If there is no particular problem in forming the coil spring 1.
2 and 13 can of course be placed at any location on the gear 6 or the hub 3. Further, in this example, one coil spring 12 and one coil spring 13 are arranged on the gear 6 and the hub 3, but it is of course possible to arrange a plurality of coil springs on the same circumference of the gear 6 and the hub 3. . Furthermore, although a coil spring is used as the torsion spring in this example, it is of course possible to employ any other appropriate torsion spring, such as a rubber spring.

[Effect of idea]

As detailed above, in the damper structure according to the present invention, the sum of the displacements of the torsion springs arranged in parallel in the axial direction of the shaft becomes the displacement of the gear with respect to the shaft, so a large displacement angle can be obtained.

Furthermore, in the damper structure according to the present invention, the number of parts is reduced as much as possible by supporting the first and second torsion springs on an intermediate member that is a single component. , disassembly, assembly work, and parts management become easier.

Further, in the damper structure according to the present invention, since the portion of the intermediate member that loosely fits into the shaft is a cylindrical portion, play of the intermediate member with respect to the shaft can be suppressed. Therefore, occurrence of gear noise due to vibration of the component parts can be prevented as much as possible.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a damper structure according to the present invention, FIGS. 2 to 4 are schematic diagrams showing the operation mode of the damper structure according to the present invention, and FIG. 5 is a side sectional view of a conventional damper structure. 6 are schematic diagrams showing the arrangement of each component in a conventional damper structure. DESCRIPTION OF SYMBOLS 1... Shaft, 3... Hub, 5... Intermediate member, 5a... Cylindrical part, 5b... Plate part, 6...
... Gear, 8 ... Hub side plate, 9 ... Gear side plate, 12 ... Coil spring (first torsion spring), 13 ... Coil spring (second torsion spring).

Claims (1)

[Scope of Claim for Utility Model Registration] Consisting of a hub fixed to a shaft, a gear rotatably provided to the shaft, a cylindrical portion loosely fitted to the shaft, and a plate portion expanding radially outward. , an intermediate member having the plate portion disposed between the hub and the gear; a first torsion spring interposed between the plate portion of the intermediate member and the gear; and a plate of the intermediate member. A damper structure comprising: a second torsion spring interposed between the second torsion spring and the hub;