JP2537287Y2 - Low mesh noise sprocket - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprocket in which mesh noise generated when chains such as a roller chain and a silent chain mesh with each other is reduced.

[0002]

2. Description of the Related Art In a conventional sprocket, the chain always collides with the tooth bottom when meshing with the chain. For this reason, the sound of collision and the sound of the lubricant such as air or oil at the root of the tooth being expelled are generated as noise. Moreover,
This noise tends to increase as the speed of the chain increases.

In order to reduce noise, there is a structure in which a rubber 22 is embedded in a tooth bottom 21 of a sprocket 20 to reduce a meshing impact of a chain, as shown in FIG. As shown in FIG. 9, rubber rings 26, 26 are provided on both sides of the sprocket 25. The rubber rings 26 receive a chain (not shown), and the chain
There is also a structure designed to reduce the impact of a collision with the vehicle.

[0004]

However, these structures have a problem that the oil attached to the chain causes the rubber to quickly deteriorate, cannot be used for a long time, and is not practical. I have.

[0005]

This invention SUMMARY OF THE INVENTION a number to form radiate
Have a plurality of overlapping sprocket plates whose teeth are formed at the same pitch and the relative position in the rotation direction is adjustable, and the teeth of the respective sprocket plates are overlapped to form meshing teeth. and, the sprocket to allow reduction by the distance between the tooth surfaces of the meshing teeth between adjusting the relative position in the rotational direction of the respective <br/> sprocket plate, solves the above problems is there.

[0006]

[Action] A plurality of sprockets constituting one sprocket
Adjust the relative position of the rotation of the
Interlocking teeth by changing the overlap of the teeth of the rocket plate
Since it reduction between the tooth surfaces distances, even if the chain mesh
Occurs, the chain is not such as to impinge on the tooth bottom gap between the switch En and the tooth bottom. Et al is, long-term wear the tooth surface or a chain of meshing teeth of the sprocket is caused by the use, if the chain is落込no possibility occurs in the tooth bottom, sprocket plate rotated relative movement, the teeth of the meshing teeth The distance between the faces can be reduced and adjusted so that the chain does not fall into the tooth bottom.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. The sprocket 30 (see FIG. 1) rotates by meshing with the chain to transmit the rotational force of the driving device to the driven device. The root 32 of the tooth 31 of the sprocket 30 is formed deeper than the root of the sprocket having a regular shape so that a gap S is generated between the roller 34 and the root 32 of the meshing roller chain (chain). I have. That is, the root circle diameter D1 of the sprocket 30 (the root circle is not shown).
Is a regular shaped root circle diameter (eg, D
2, and the regular root circle is also formed smaller than the diameter (not shown). For this reason, the roller 34 meshed with the sprocket 30 is caught between the tooth surfaces 35 and does not mesh with the tooth bottom 32. Therefore, due to the gap S generated between the roller 34 and the tooth bottom 32, the noise of expelling lubricant such as air or oil at the tooth bottom 32 is reduced. Further, since the roller 34 does not hit the tooth bottom 32, the noise due to the meshing impact between the sprocket 30 and the roller chain 33 is also reduced.

Next, a description will be given, using a mathematical expression, of how the meshing impact noise is reduced by the meshing of the rollers 34 so as not to contact the tooth bottom 32. In FIG. 2, the relative approach speed between the sprocket teeth 31 and the rollers 34 of the roller chain is V, the tangent L1 on the tooth surface 35 at the point P where the rollers 34 contact the teeth 31 and the center line L2 of the sprocket.
Assuming that the angle between A and A is A, the speed v at which the roller 34 hits the tooth surface 35 is v = V · sinA. In the conventional tooth mold, the angle A is about 90 ° because the roller 34 hits the tooth bottom.
It is. Therefore, v and V are almost equal. In the case of the tooth form of the embodiment, if A = 30 °, v = 0.5 V, and the speed at which the roller 34 collides with the teeth 31 is lower than that of the related art. Further, the meshing noise is expressed as E = (1 /
2) Since the energy can be represented by the formula of m · v square (where m is the mass of a part of the chain meshing with the teeth), the square of (１ ／) = 0.25, that is, the roller The energy amount when the teeth 34 and the teeth 31 mesh with each other is reduced to about (1/4) of the conventional one, and the meshing noise is reduced.

Next, a sprocket according to another embodiment will be described. The sprocket 40 shown in FIG. 3 to FIG. 5 is used when the teeth 41 of the sprocket 40 and the rollers 34 of the chain (not shown) are worn due to long-term use, and there is a possibility that the rollers drop to the tooth bottom. It has a structure that can prevent dropping. This sprocket 40
Is composed of one reference sprocket plate 42 and a pair of adjustment sprocket plates 43, 43.

The reference sprocket plate 42 has a boss 45 attached to a rotating shaft 44 and four long holes 46 formed on the same circle with the rotating shaft 44 as a center. Four bolt holes 48 are formed in the pair of adjusting sprocket plates 43 and 43 so as to face the long holes 46 and through which bolts 47 pass. A pair of adjusting sprocket plates 43,
The reference numeral 43 designates the relative position of the reference sprocket plate 42 in the rotational direction adjustable by the guide of the long hole 46 and the bolt 47. It has become.

[0011] This like reference sprocket plate 42 and the adjusting sprocket plate 43, respectively radially plurality of teeth 50, 5
1 are protruded at the same pitch . By overlapping teeth 50 and 51, engaging teeth 4 of the sprocket 40
1 is formed. The tooth bottom 52 of the meshing tooth 41 of the sprocket 40 is also formed deeper than the tooth bottom of the regular sprocket. That is, the tooth bottom circle diameter of the sprocket 40, Sunawa
The roller chain meshing with the sprocket teeth 41
It is formed smaller than the roller diameter .

If the wear of the chain for a long period of time causes the roller 34 of the chain to fall into the tooth bottom 52, the bolt 47 is loosened, and the pair of adjusting sprocket plates 43, 43 are moved relative to the reference sprocket plate 42. 3 in the direction of the arrow B shown in FIG.
4 can be adjusted so as not to fall into the tooth bottom 52.

Further, a sprocket of another embodiment will be described. This sprocket 60 (see FIGS. 6 and 7)
Is composed of one reference sprocket plate 61 and one adjustment sprocket plate 62.
63 and worm wheel 64 to adjust the position of
And The worm 63 is an adjustable sprocket plate 6
2, the worm wheel 64 is mounted on the reference sprocket plate 61.
Are provided respectively.

The position of the adjusting sprocket plate 62 can be adjusted in the rotational direction with respect to the reference sprocket plate 61 by the guide of the elongated holes 65 and the bolts 66.
By tightening the bolt 66, the reference sprocket plate 6
One and one. The reference sprocket plate 61 and the adjusting sprocket plate 62 also have a plurality of teeth 67,
68 project at the same pitch . And teeth 67,6
8 by allowing each superimposed, sprocket 60
Are formed. This sprocket 60 bites
The root 70 of the tooth 69 also matches the tooth 69 of the sprocket.
It is formed smaller than the roller diameter of the meshing roller chain .

If the rollers of a chain (not shown) may fall into the tooth bottom 70 due to wear caused by long-term use of the sprocket 60, the bolt 66 is loosened and the worm 63 is rotated to adjust the sprocket. Board 6
Tooth surfaces of the meshing teeth 2 and the reference sprocket plate 61 7
It is rotated in a direction to narrow the spacing between 1,72, each spray
By changing the degree of overlap of the teeth of the rocket plate , the reduction can be adjusted so that the roller does not fall into the tooth bottom 70.

If the worm 63 is provided with a mechanism for keeping the torque constant (not shown), the wear and elongation of the chain can be automatically adjusted. That is, the chain
When wear elongation occurs, a constant torque is constantly applied to the worm 63 such that the distance between the tooth surfaces 71 and 72 of the meshing teeth is reduced and the adjusting sprocket plate 62 is rotated in a direction to remove the slack of the chain. It is good to do so.

The reference sprocket plates 42 and 61 of the above sprockets 40 and 60, and the adjustment sprocket plate 4
At 3,43,62 teeth 50,51,67,68,
The surface on the opposite side of the surface forming the meshing teeth 53, 54, 71, 72 does not necessarily need to be formed in a tooth shape because the chain does not mesh.

[0018]

[Effect of the Invention] The sprocket of the present invention has a plurality of sprockets.
Rotate the rocket board in the direction of rotation to adjust the relative position
Change the overlapping of the teeth of each sprocket plate, meshing teeth
The distance between the tooth surfaces of the chain is reduced , a gap is created between the chain and the tooth bottom, and the chain is prevented from dropping into the tooth bottom of the sprocket. It is possible to reduce the noise of a lubricant such as oil being expelled, and to reduce noise.
Furthermore, the use of long periods, wear the meshing tooth surfaces of the chain and the sprocket occurs, if the chain is落込no possibility occurs in the tooth bottom, is rotated moving the sprocket plate each
Adjust the relative position to reduce the distance between the tooth surfaces of the meshing teeth.
And the chain can be落込or internal use in tooth root.

[Brief description of the drawings]

FIG. 1 is a front view of the sprocket of the present invention.

FIG. 2 is an explanatory diagram of a meshing state between a sprocket and a chain.

FIG. 3 is a front view of a sprocket according to another embodiment.

FIG. 4 is a cross-sectional view of the sprocket of FIG. 3 taken along a rotation axis.

FIG. 5 is an exploded perspective view of the sprocket of FIG. 3;

FIG. 6 is a front view of a sprocket according to another embodiment.

FIG. 7 is a sectional view taken along arrow 7-7 in FIG.

FIG. 8 is a perspective view of a conventional sprocket.

FIG. 9 is a sectional view of a conventional sprocket.

[Explanation of symbols]

D1 root circle diameter S gap 30, 40, 60 sprocket 32, 52, 70 root 33 roller chain (chain) 35, 53, 54, 71, 72 tooth surface 41, 69 meshing teeth 42, 61 reference sprocket plate (sprocket) Plate) 43,62 Adjustable sprocket plate (sprocket plate) 50,51,67,68 teeth

Claims (2)

(57) [Scope of request for utility model registration] 1. A plurality of teeth are radially formed at the same pitch.
The relative position in the direction of rotation is adjustable and overlapped
It has a plurality of sprocket plates, and each sprocket
The teeth of the plate are overlapped to form a meshing tooth, and the meshing teeth are
The distance between the tooth surfaces is determined by the rotation direction of each sprocket plate.
Can be reduced by adjusting the relative position of
A low-meshing noise sprocket characterized by: 2. A plurality of sprocket plates having radially projecting pieces formed thereon and capable of relatively adjusting the position in the rotation direction, wherein the sprockets are overlapped with each other to form teeth, and the teeth are formed. The distance between the tooth surfaces of the sprocket can be changed by adjusting the position of the sprocket plate.