JPH06288463A - Timing pulley - Google Patents

Abstract

PURPOSE:To damp vibration generated by the mesh of teeth so as to suppress the generation of noise by providing a timing pulley with cavities inside, and disposing powder/grain movably in the cavities. CONSTITUTION:An upper shaft pulley 10, a timing pulley, is formed of a pulley body 10c with sector cavities 10a disposed at equal spaces apart at several places around a rotary shaft, and a pulley lid 10b. Approximately ball-shaped lead powder/grain 13 of about 2-3mm or smaller in diameter is filled in each cavity 10 and closed by the pulley lid 10b. When a motor 11 is driven, the upper shaft pulley 10 is driven through a driving belt 12, and an upper shaft 1 is rotated. The teeth of the driving belt 12 are meshed with the teeth of the upper shaft pulley 10 and those of the small pulley of a motor shaft, and the teeth are vibrated by the mesh when the motor 11 is driven. The upper shaft pulley 10, however, has the built-in powder/grain 13 inside so as to suppress the vibration generated by the mesh of the teeth. As a result, noise is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timing pulley that drives or is driven by a timing belt.

[0002]

2. Description of the Related Art Conventionally, transmission by a belt and a pulley has been widely used as a means for transmitting a driving force from a driving source such as a motor. There are two types, one is a flat belt or a V-belt, which transmits a rotational force by frictional transmission, and the other is a timing belt, which is a meshing transmission. However, since some friction is inevitable in the frictional transmission, when synchronous transmission is required, it must be meshing transmission.

A timing belt is generally formed by covering a core wire such as glass fiber or nylon cord with an elastomer such as rubber or resin, and transmits power by meshing with a timing pulley.

[0004]

However, the conventional timing pulley has a problem in that due to the meshing of the timing belt and the pulley, a large noise is generated at the meshing frequency and its harmonics.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a timing pulley in which vibration due to meshing of teeth is attenuated and noise is less likely to occur.

[0006]

In order to achieve this object, the timing pulley of the present invention has a cavity inside, and the powdery or granular material is movably disposed in the cavity. Alternatively, a container having powder particles enclosed therein was attached.

[0007]

In the timing pulley of the present invention having the above-mentioned structure, a vibration suppressing effect is produced by the collision of the powder or granular material with the cavity containing the powder or granular material or the inner wall of the container.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram showing an example in which the present invention is applied to an upper shaft pulley of a domestic sewing machine. The sewing machine of this embodiment includes an upper shaft 1 for driving a needle bar, a balance, etc. (not shown), a lower shaft 4 for driving a rotary hook 2, a feed dog 3, etc., and a horizontal feed shaft 5. The lower shaft 4 is linked to the rotation of the upper shaft 1 by a crank rod 6 and a lower crank 7, and the horizontal feed shaft 5 is linked by a feed rod 8 and a horizontal feed arm 9.

An upper shaft pulley 10 is attached to one end of the upper shaft 1, and a small pulley (not shown) provided at the tip of the motor shaft of a motor 11 attached to a frame (not shown) and a drive belt 12. Are connected via. The upper shaft pulley 10 and the small pulley are timing pulleys whose outer circumference is toothed, and the drive belt 12 is a timing belt whose surface has teeth that mesh with the teeth of the pulleys.

FIG. 1 is an exploded perspective view of the upper shaft pulley 10 of FIG. 2, and FIG. 3 is the same as the upper shaft pulley 10 of FIG.
It is an A line sectional view.

The upper shaft pulley 10 is composed of a pulley body 10c having fan-shaped cavities 10a which are arranged around the rotating shaft at several places at equal intervals, and a pulley lid 10b. A substantially spherical lead powder granule 13 having a diameter of about 2 to 3 mm or smaller is enclosed in the cavity 10a and is sealed by a pulley lid 10b.

For the relationship between the mass and particle size of the powder and granules 13 and the vibration damping effect, see "Powder and granule impact damper (Araki et al. 2
Name, mechanism, 49-442, C) "," Characteristics of powder-particle impact damper (Araki et al., 2 persons, mechanism, 50-459, C) " By setting these values to appropriate values according to the exciting force, the exciting frequency, etc., a good damping effect can be obtained in a wide frequency range.

The operation of the household sewing machine of this embodiment will be described below with reference to FIGS. When the motor 11 is driven, the upper shaft pulley 10 is driven via the drive belt 12 and the upper shaft 1 rotates. The rotation of the upper shaft 1 is transmitted to a needle bar, a balance, and the like (not shown), and these reciprocate. on the other hand,
The rotation of the upper shaft 1 is transmitted to the lower shaft 4 by the crank rod 6 and the lower shaft crank 7, and to the horizontal feed shaft 5 by the feed rod 8 and the horizontal feed arm 9 to drive the rotary hook 2, the feed dog 3 and the like. In this way, the needle bar, the balance, and the like are driven by the single upper shaft 1 so that the rotary hook 2, the feed dog 3, and the like are synchronized, and the cloth is sewn.

The teeth of the drive belt 12, the teeth of the upper pulley 10, and the teeth of the small pulley of the motor shaft are in mesh with each other. When the motor 11 is driven, the teeth vibrate due to the mesh. However, the upper pulley 10 has the powder particles 13 incorporated therein to suppress the vibration generated by the meshing of the teeth. As a result, noise is also reduced.

FIG. 4 is an exploded perspective view showing another embodiment of the timing pulley.

The pulley 40 includes a pulley body 40c and fan-shaped through holes 40 arranged at equal intervals around the rotation shaft.
It is composed of a ring 40d having a and a pulley lid 40b. The through hole 40a has a diameter of 2 to 3 m.
Approximately spherical or smaller lead powder granules 4
3, the openings at both ends of the through hole 40a are sealed by the pulley body 40c and the pulley lid 40b.

In the timing pulley having such a structure,
As compared with the first embodiment, the through hole 40a can be processed more easily and the assemblability is better. Moreover, the vibration damping effect similar to that of the first embodiment can be obtained.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention. For example, although lead powder granules are used in the above-mentioned embodiments, various materials such as copper and iron can be used. Further, the shape of the cavity for enclosing the powder or granular material is not limited to the fan shape, and can be processed by forming a round hole, an oval hole, or the like. Further, in the above-described embodiment, the case where the timing pulley of the present invention is applied to the upper shaft pulley of the domestic sewing machine has been described in detail, but the timing pulley of the present invention may be used for the small pulley on the motor side. Also, the printer,
The present invention can be applied to any product, such as a copying machine or a facsimile, as long as the noise caused by the meshing of the timing belt and the timing pulley causes a problem.

[0020]

As is apparent from the above description, according to the timing pulley of the present invention, the vibration due to the engagement between the timing belt and the pulley is attenuated and the noise generated thereby is reduced with a simple structure. be able to.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment embodying the structure of a timing pulley of the invention.

FIG. 2 is a schematic view showing an example in which the timing pulley of the present invention is applied to an upper shaft pulley of a household sewing machine.

3 is a cross-sectional view of the upper shaft pulley taken along the line AA in FIG.

FIG. 4 is an exploded perspective view showing another embodiment of the timing pulley of the present invention.

[Explanation of symbols]

 10 Upper Shaft Pulley 10a Cavity 13 Powder Granule 40d Ring

Claims (2)

[Claims] 1. A timing pulley that meshes with a timing belt to transmit power, wherein the timing pulley has a cavity inside and a powder or granular material is movably disposed in the cavity. 2. A timing pulley that meshes with a timing belt to transmit power, wherein a container in which powder particles are enclosed is attached.