JPH01247858A - Chain transmission mechanism - Google Patents

Abstract

PURPOSE:To prevent vibration of a rotary shaft, by a method wherein a plurality of sprockets are mounted on a rotary shaft in a manner to displace phases from each other, and independent chains are run around respective sprockets. CONSTITUTION:A sprocket 3 is rotatably mounted on a rotary shaft 1 through bearings 4 and 5, and a second sprocket having the same pitch circle diameter and the same number of teeth as those of the sprocket 3 is spline-engaged with a boss part 6 of the sprocket. The rotary shaft 1 can be coupled to the boss part of the sprocket 3 through a slide clutch 10, and integral rotation is practicable. The sprockets 3 and 7 are mounted in a manner to displace phases from each other by a half pitch. Through vertical displacement produced at silent chains 11 and 12 independently run around the sprockets 3 and 7, respectively, vibration is offset to each other by means of displacement in a phase, and vibration transferred to the rotary shaft 1 is prevented from occurring.

Description

[Detailed description of the invention] Industrial field of application This light is used for transmission FR1, which transmits other forces through a chain.
It is related to.

As is well known in the art, the chain transmission l11g14f4 transmits external force by meshing the chain with the teeth of the sprocket, so the rotation ratio can be reliably maintained and the drive angle that can be transmitted is large. It has the following advantages and is used in various fields. On the other hand, they also have the disadvantage of producing large amounts of vibration and noise due to the meshing between the sprocket and chain and the inability of the links themselves to bend. A silent chain is known as a chain that reduces as much as possible the disadvantages of such a chain transmission VJ mechanism, and is used in a transformer 71 for four-wheel drive and the like. This silent chain has a pair of teeth set at a predetermined face angle on the inner circumferential side of the link, and a large number of links are connected in the thickness direction and longitudinal direction, and both sides of each link are By closely contacting the side surfaces of the sprocket teeth and transmitting VJ'1J, quiet operation is possible.

However, even with a silent chain, the links themselves cannot bend, so when wrapped around the sprocket they move in a polygonal fashion.As a result, the higher the rotation speed, the more the chain moves up and down, causing vibrations in the rotating shaft. This causes noise. Conventionally, in silent chains, for example, an elastic body such as a leaf spring is attached to the guide link row, and the *
* Chain vibration is suppressed by force.

In Japanese Patent Publication No. 56-4780, a special 4M structure →Filent chain transmission device was developed, in which a pair of teeth formed on the link was connected to a groove with a recess formed between the gaps. The links are constructed so that only the outer side surfaces are aligned with the teeth of the sprocket, and the sprockets are arranged so that the teeth of adjacent sprockets are shifted by half a pitch. The wiA location created is described.

The problem that Komei is trying to solve However, with a structure in which elastic bodies are inserted between the links, the vertical vibration of the chain between the sprockets can be suppressed by the friction force between the links and between the links and the elastic body. Therefore, there is a problem in that the higher the rotation speed, the more light and heat is generated.

Furthermore, in the device described in the above-mentioned publication, all links are made into a special shape similar to the guide link in order to increase the strength of the links, and the teeth of the sprocket ρ are removed so that they are shifted by half a pitch due to warping. Therefore, the relative relationship between the chain and sprocket is no different from that of one chain and one sprocket, and therefore it is impossible to suppress the contact movement of the chain.

This invention was made in consideration of the above circumstances, and R
pI! 8. It is an object of the present invention to provide a chain transmission mechanism that can suppress vibration of a rotating shaft without causing vibration.

Means for Solving Problem A This light uses multiple pairs of chains and sprockets to achieve the above purpose, and also makes the phases of the proceratoms different, thereby generating the vibrational force generated by the multiple pairs of chains. The invention is characterized in that it is configured to interfere with the imaging of the rotation axis to suppress imaging of the rotation axis.

More specifically, this light is characterized in that a plurality of sprockets are attached to a rotating shaft, the phases of the sprockets are shifted from each other, and independent chains are wrapped around each sprocket.

Therefore, according to the chain transmission tlJ mechanism of this invention,
Driving force is transmitted through multiple chains, but because the sprockets are in different phases, the effective radius of any sprocket becomes larger and the chain is pushed toward the outer circumference. , in other sprockets, the radius becomes substantially smaller and the chain moves toward the inner circumference, resulting in the so-called vertical movement of one of the chains, and the vertical movement of the other chain occurs in the opposite direction. Therefore, the acting constraints φ from the chain on the rotating shaft cancel each other out, and as a result, the vibration of the rotating shaft is suppressed.

Example Next, embodiments of the invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention, in which a drive shaft 1 is rotatably supported by a bearing 2, and a sprocket 3 is attached to the outer periphery of a small diameter portion of the drive shaft 1.
is rotatably mounted via a bearing 4.5. This sprocket 3 has a boss portion 6 having an outer diameter equal to that of the rotating shaft 1, and a second sprocket 7 having the same pitch circle radius and the same number of teeth as the sprocket 3 is spline-fitted to the boss portion 6. It is fixed with a snap ring 8. Further, a spline 9 is formed on the outer periphery of the rotating shaft 1,
A clutch 10 is fitted to the spline 9 so as to be slidable in the axial direction, and the clutch 10 is also engaged with the boss portion 6 of the sprocket 3 as shown in FIG. They are integrated in the direction of rotation. Furthermore, a silent chain 11.12 is wound around each sprocket 3.7. As shown in FIG. 2, the sprockets 3.7 are mounted with a half-pitch (p,' 2 > phase shift) from each other.

The driving force is transmitted through the silent chains 11 and 12 by connecting the rotating shaft 1 and the sprocket 3 with the clutch 10. sprocket 3
Since the and second sprocket 7 are spline-fitted and are substantially integrated, they rotate as one, and the I/78 and each silent chain 11, 12 run as shown in the figure. The driving force vJ7J is transmitted to the sprocket on the driven side that is not connected.

In that case, each sprocket 3.7 carries out a polygonal movement, so that the silent chain 11.12 shown in FIG.
As shown in A>(B), it is displaced toward the inner circumferential side and the outer circumferential side (in the vertical direction in the figure), and therefore vibrations as shown in FIG. 4 are generated. However, in the above transmission mechanism, for example, the first sprocket 3 rotates to the position shown in FIG. 3(A), and the silent chain 12 is displaced from the minimum radius position to the maximum radius position (this displacement Φ is referred to as If you did,
The other silent chain 12 connects each sprocket 3.
7 is out of phase by half a pitch, as shown in Figure 3 (B
), it is displaced from the maximum radius position to the minimum radius position. Therefore, the vibration of the first silent chain 11 becomes the vibration shown by the solid line in FIG.
The vibration of the continuous chain 12 is as shown by the broken line in FIG. 4, and both waveforms have opposite phases. The size is also the first
In contrast to the excitation force applied to the rotating shaft 1 from the second silent chain 11, an excitation force in the opposite direction is applied to the rotating shaft 1 from the second silent chain 12, and as a result, the two interfere with each other. Therefore, vibration of the rotating shaft 1 is suppressed or prevented.

Although the above embodiment has been explained by taking a silent chain as an example, this explanation is not limited to the above embodiment, but can also be applied to a conventional chain using a normal O-La chain. Furthermore, in this invention, since the vibrations of the chain interfere with each other and cancel out the iE excitation force, it is not necessary to use a single pair of chain and sprocket. You can also use it as

As described in detail, according to the chain transmission VJ mechanism of the present invention, since the chains are independent from each other and the sprockets are out of phase, the vibrations of the chains interfere with each other and cause vibrations to the rotating shaft. This cancels out the forces, and as a result, the vibration of the rotating shaft is suppressed or prevented, resulting in a quiet transmission.
Furthermore, since the present invention does not increase the friction of the links, it is possible to suppress the light and heat of the chain.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, FIG. 2 is a partial diagram for explaining the relative positional relationship of each sprocket,
FIG. 3 <A><B) is a partial view showing the state of the chain wrapped around each sprocket, and FIG. 4 is a diagram showing the vibration waveform of each chain. 1... Rotating shaft, 3, 7... Sprocket, 11
゜12...Silent chain. Applicant: Toyota Motor Co., Ltd. Volk Warner Automotive Co., Ltd. Agent Attorney T: 1) Hisashi Take (one idiot) Figure 1 Figure 2

Claims (1)

[Claims] A chain transmission mechanism characterized in that a plurality of sprockets are attached to a rotating shaft, the phases of the sprockets are shifted from each other, and independent chains are wound around each sprocket.