JPH0949555A - Floating chain guide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of noise and vibration from a roller chain and provide a minimum installation space and low-cost manufacture with a simple structure. SOLUTION: This guide device is provided with a sprocket 1 whose peripheral surface is formed with an annular groove so that a groove bottom 2A may be positioned to the more middle side than a tooth bottom 3, and an arc-shaped inner peripheral surface 4D rotatably-fitted onto the annular groove, and a roughly C-shaped plate-type floating chain guide 4 which has a semi-arc outer periphery 4A whose radius is roughly equal to the root circle of the sprocket 1, and a pair of roller guide surfaces 4B, 4C extending in the tangential direction respectively from both ends of the semi-arc outer periphery 4A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing fluctuations in the position of a roller chain that meshes with a sprocket of a roller chain transmission, the position of the roller chain entering the sprocket.

[0002]

2. Description of the Related Art A conventional chain transmission, as shown in FIG. 5, is a roller 1 that meshes with teeth of a sprocket 11 when meshing with a sprocket 11 of a roller chain 15.
Since the position of 6 is different between the position of the sprocket 11 shown in (a) of the figure with the rotation of the sprocket and the position of the sprocket 11 shown in (b) of the figure where the sprocket 11 is rotated by a half pitch, the position of the roller chain 16 is different. There has been a problem that the traveling path fluctuates by δ, causing vibration and noise in the roller chain.

As a countermeasure, a roller chain having a short pitch is used, and the number of teeth of a sprocket meshing with the roller chain is increased to reduce the fluctuation. At that time, if the pitch is shortened, the size of the roller chain becomes small, and the strength of the ordinary roller chain is insufficient. Therefore, a roller chain composed of a link plate having high strength or a multi-row chain is used. As another measure,
The apparent pitch is shortened by using a multi-row roller chain in which the rollers are out of phase with each other.

As yet another measure, Japanese Patent Publication No. 54-5
As described in Japanese Patent No. 8163, a guide tool for slidably supporting the roller chain is arranged in the vicinity of a portion where the roller chain meshes with the sprocket, and the guide tool allows the roller chain to enter the sprocket. There is a device that prevents the position from changing.

[0005]

However, when a link plate having a high strength is used or a chain of multiple rows is used, there is a problem that the manufacturing cost becomes high, and it is described in JP-B-54-58163. When arranging such a guide tool, there is a problem that a structure and an installation space for fixing the guide tool are required.

Therefore, the present invention solves the above-mentioned problems of the conventional technique and has a simple structure, which can prevent noise and vibration from occurring in the roller chain, and does not require an installation space and can be manufactured at low cost. An object of the present invention is to provide a floating chain guide device that can be used.

[0007]

To achieve the above object, the floating chain guide device of the present invention comprises a sprocket having an annular groove formed on its peripheral surface so that the groove bottom is located closer to the center of rotation than the tooth bottom. While having an arcuate inner peripheral surface rotatably fitted in the annular groove, a semi-circular outer peripheral surface having a radius substantially equal to the root circle of the sprocket and tangentially from both ends of the semi-circular outer peripheral surface. It is composed of a plate-like floating chain guide formed in a substantially C-shape having a pair of roller guide surfaces extended respectively.
The floating chain guide is preferably made of a resin material.

[0008]

In general, the position where the roller chain enters the sprocket fluctuates every time the rotational position of the sprocket rotates by half a pitch. However, according to the floating chain guide device of the present invention, the roller chain roller that enters the sprocket is prevented. Since the roller guide surface of the floating chain guide incorporated in the sprocket supports it, fluctuations in the position of the roller chain entering the sprocket are prevented. As a result, the roller chain is guided by the sprocket in a constant traveling path, and vibration and noise are prevented.

In particular, when the floating chain guide is made of a resin material, friction with the roller is small and the roller chain is guided smoothly. Further, since the resin material has a large vibration damping effect, the vibration and noise prevention effect can be enhanced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing one embodiment of the floating chain guide device of the present invention, and FIG. 2 is A- of FIG.
It is a cross-sectional view taken along the line A, and an annular groove 2 is formed on the outer peripheral surface of the sprocket 1. Groove bottom 2 of the annular groove 2
A is formed so as to be located closer to the center of rotation than the tooth bottom 3 of the sprocket 1, and the teeth of the sprocket 1 are divided into two in the thickness direction by the annular groove 2. The width of the annular groove 2 is 1/3 of the width of the teeth of the sprocket 1.
It is set to about 1/4.

A floating chain guide 4 for guiding a roller chain (not shown) wound around the sprocket 1 is rotatably fitted in the annular groove 2. The floating chain guide 4 is formed in a substantially C shape by a resin plate body having a thickness matching the groove width of the annular groove 2. As a material of the floating chain guide 4, a resin having excellent sliding characteristics such as nylon 46 and nylon 66 is suitable.

The floating chain guide 4
Is a semi-circular outer peripheral surface 4A having a radius R1 substantially equal to the radius of a root circle passing through each bottom 3 of the sprocket 1, and a pair tangentially extending from both ends of the semi-circular outer peripheral surface 4A. Roller guide surfaces 4B and 4C. Further, the floating chain guide 4 has an arcuate inner peripheral surface 4D having a radius R2 and adapted to the groove bottom 2A of the annular groove 2 of the sprocket 1.

The semi-circular outer peripheral surface 4A is formed so that the central angle with respect to the center of the sprocket 1 is substantially equal to the winding angle of the roller chain. That is, when the number of teeth of the other sprocket combined with the sprocket 1 is greater than the number of teeth of the sprocket 1, the central angle is smaller than 180 degrees, and the number of teeth of the other sprocket 1 is the number of teeth of the sprocket 1. If less, the central angle is formed to be greater than 180 degrees.

The inner peripheral surface 4D has a sprocket 1
Is formed in a range of a central angle larger than the central angle of the semi-circular outer peripheral surface 4A with respect to the center of the sprocket 1
It is fitted to the groove bottom of the annular groove 2 and can freely rotate around the annular groove 2. In FIG. 2, the width (R1-R2) of the floating chain guide 4 is R1-R2 = 2, where d is the roller diameter of the roller chain.
d / (3-5) is suitable.

Further, in this embodiment, when the number of teeth of the sprocket 1 is N, the roller guide surfaces 4B and 4C and the inner peripheral surface 4D are θ = 360 degrees / N, as shown in FIG.
Is formed in a region having a length that reaches an intersection with straight lines X and Y drawn outward from the center O of the sprocket 1 at an angle of, and both ends of the floating chain guide 4 are The roller guide surfaces 4B and 4C and the inner peripheral surface 4D are formed by connecting each of them with a smooth curve with such a length as to fit within the radius of one tooth tip circle. However, θ is an angle with reference to a line connecting both ends of the semicircular outer peripheral surface 4A and the center O of the sprocket 1.

FIG. 3 shows the roller support state of the floating chain guide when the roller chain 5 enters the floating chain guide device of the present invention. In the rotational position of the sprocket 1 shown in FIG. Semicircular arc-shaped outer peripheral surface 4 of the floating chain guide 4
One of the teeth of the sprocket 1 is located at the position of the boundary P between the A and the roller guide surface 4B, and at the position on the front side of the tooth in the rotation direction, the roller 6 is moved by the upper surface of the roller guide surface 4B.
It is supported in a state of being floated from the tooth bottom 3 of the sprocket 1.

In FIG. 4, the sprocket 1 is rotated by a half pitch from the position of FIG. 3, and the teeth of the sprocket 1 are located at the boundary P between the semicircular arc-shaped outer peripheral surface 4A of the floating chain guide 4 and the roller guide surface 4B. The bottom 3 has been moved, and at this position, the upper surface of the floating chain guide 4 and the tooth bottom 3 of the sprocket 1 are substantially at the same level. While the tooth bottom 3 moves to this position, the roller 6 is tangentially approaching the sprocket 1 while being supported by the upper surface of the roller guide surface 4B, and the path of the roller chain 5 entering the sprocket 1 is It is kept constant.

The roller guide surface 4C provided on the opposite side of the roller guide surface 4B of the floating chain guide 4 comes into contact with the roller 6 on the return side of the roller chain 5 so that the floating chain guide 4 can be oriented in a fixed direction. Plays a role in keeping in. Further, when the sprocket 1 is used in reverse, the roller guide surface 4C suppresses the position variation of the entry path of the roller chain 5 into the sprocket 1.

Since the annular groove 2 is formed, the effective contact area between the roller 6 and the tooth surface of the sprocket 1 is reduced.
Since the traveling path of the roller chain 5 is kept constant,
The impact force due to the collision between the roller 6 and the tooth surface is almost eliminated, the transmitted power is not reduced, and the life of the sprocket 1 and the roller chain 5 is not reduced.

Further, in the above-mentioned embodiment, since the resin material having self-lubricating property and damping property of vibration and noise is used as the material of the floating chain guide 4, the roller 6 meshes with the sprocket 1. Although the noise generated at this time is suppressed as much as possible, the floating chain guide 4 may be formed of a metal plate or the like as long as the conditions such as lubrication are good.

[0021]

As described above, in the floating chain guide device of the present invention, since the floating chain guide for guiding the roller chain is incorporated in the sprocket itself, no special mounting structure or installation space is required. Moreover, since the floating chain guide can freely rotate following the tension direction of the roller chain, it can be used with extremely high degree of freedom.

Further, even when the number of teeth of the sprocket is small, it is possible to surely suppress the fluctuation of the traveling path of the roller chain that enters the sprocket, so that it is very effective in preventing the vibration and noise of the roller chain. Is obtained. Therefore, in particular, by using the floating chain guide device of the present invention in the drive portion of the chain conveyor where a sprocket having a small number of teeth of 6 to 10 is usually used, it is possible to significantly reduce noise generation.

Further, since the floating chain guide device of the present invention has a simple structure in which the plate-shaped floating chain guide is incorporated into the sprocket having the annular groove, it can be manufactured at low cost.
In particular, when the floating chain guide is made of a resin material, the friction with the roller is small and the roller chain can be smoothly guided, and the vibration damping effect is large, so the vibration and noise prevention effect is further enhanced. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a floating chain guide device of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 showing an embodiment of the floating chain guide device of the present invention.

FIG. 3 is a view showing a roller support state of a floating chain guide.

FIG. 4 is a view showing a roller support state of the floating chain guide at a position where the sprocket is rotated by a half pitch from the position shown in FIG.

FIG. 5 is a diagram showing fluctuations in the meshing position of the roller chain depending on the rotation position of the sprocket.

[Explanation of symbols]

 1 Sprocket 2 Annular groove 2A Groove bottom 3 Tooth bottom 4 Floating chain guide 4A Semi-circular outer peripheral surface 4B, 4C Roller guide surface 4D Inner peripheral surface 5 Roller chain 6 Roller

Claims (2)

[Claims] 1. A sprocket having an annular groove formed on its peripheral surface such that the groove bottom is located closer to the center of rotation than the tooth bottom, and an arcuate inner peripheral surface rotatably fitted in the annular groove. And a pair of roller guide surfaces extending tangentially from both ends of the semi-arcuate outer peripheral surface having a radius substantially equal to that of the root circle of the sprocket and a pair of roller guide surfaces. A floating chain guide device including a formed plate-shaped floating chain guide. 2. The floating chain guide device according to claim 1, wherein the floating chain guide is made of a resin material.