JPH068364Y2 - Silencer gear - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a sound deadening gear designed to prevent meshing noise generated during meshing of gears.

[Conventional technology]

Backlash is generally added to gears. This is because, if the backlash is eliminated, the teeth will squeak and the smooth motion will be hindered due to errors in gear manufacturing and deformation of the gear during motion. However, the presence of backlash causes another problem that noise is generated due to tooth abutment due to play between teeth of meshing gears.

Therefore, conventionally, various gears have been proposed in which rotation can be smoothly transmitted without backlash in order to prevent noise.

FIG. 3 shows a conventional example of this type of gear, in which each tooth 1a of the gear 1 is integrally formed of elastic synthetic resin or the like.
A recess 1d extending from the root 1b toward the tip 1c
In addition to integrally forming the tooth 1a, the tooth thickness of each tooth 1a is increased by a dimension almost equal to the backlash, and the width of the tooth groove is reduced by that amount. It is deformed to allow smooth transmission of driving force without causing tooth creaking.

FIG. 4 shows another example, in which the base portion 2b of the tooth 2a of the gear 2 is
The base 2b is elastically deformable in the directions of arrows A, B, and C by forming the vertical arm 2c and the horizontal arm 2d that are thin and are formed in an L shape so as to project in the direction orthogonal to the surface of the gear 2. Even if there is no backlash, the drive force can be smoothly transmitted by the movement of the teeth 2a.

[Problems to be solved by the invention]

In the above-mentioned conventional gear, since each small tooth of the gear is molded so as to be elastically deformable, it is extremely difficult to control elasticity,
The elasticity of each tooth varies, and the applicable rotation transmission speed of each gear is narrow, which makes it unsuitable for a wide range of rotation transmission from low speed to high speed. That is, it is necessary to prepare a gear in which the elasticity of each tooth is changed according to the rotation speed used.

Therefore, in view of the above-mentioned drawbacks of the conventional ones, the present invention intends to provide a muffling gear whose elasticity is relatively easy to manage and which can be used for rotation transmission in a wide range of speeds from low speed to high speed.

[Means for solving problems]

In order to solve the above-mentioned problems, a sound deadening gear made according to the present invention has a first tooth portion meshed with a drive gear and a second tooth portion meshed with a driven member. Which is used to transmit the rotation of the rotation member to the driven member, the rotation center portion being integrally formed with the second tooth portion and rotatably supported by the shaft; Elasticity consisting of arc-shaped rims that connect the first tooth portions concentrically and connect the rotation center portion and the first tooth portion so as to relatively move in the circumferential direction and the radial direction by elastic deformation. And a connecting portion, wherein the rotation center portion, the first tooth portion, and the elastic connecting portion are integrally formed of a synthetic resin having elasticity, and the distance between the rotation axis of the drive gear 1 and the shaft is set to the drive value. Slightly smaller than the sum of the radius of the gear and the first tooth portion It is characterized.

[Action]

With the above configuration, the distance between the rotating shafts of the first tooth portion and the drive gear is made smaller than the sum of the radii of the first tooth portion and the drive gear, so that the distance between the rotation center portion and the first tooth portion is reduced. The elastic connecting portion formed of arc-shaped rims that are connected concentrically elastically deforms, and the rotation center portion and the first tooth portion relatively move in the circumferential direction and the radial direction, impairing smooth transmission of the driving force. The first tooth portion is constantly pressed against the teeth of the driving gear to eliminate backlash, and noise due to abutment of teeth due to backlash between tooth surfaces is eliminated without impairing smooth transmission of driving force. .

Also, since the elastic connection part consists of an arc-shaped rim,
Even for gears with small diameters, the length of each rim can be made large,
The amount of deformation per unit length of the rim can be reduced, and the pressure contact force between the teeth becomes substantially uniform over the entire circumference of the first tooth portion, and from this point as well, smooth rotation drive force transmission Is done.

Further, since the rotation center portion, the first and second tooth portions, and the elastic connecting portion are integrally formed of the elastic synthetic resin, the cost is very low and the gear can be obtained with a small size and high precision. .

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 10 is a stepping motor, and a pinion gear 11 made of, for example, a synthetic resin or the like is fixed to a rotating shaft 10a thereof. Reference numeral 12 denotes a sound deadening gear to which the present invention is applied, which is integrally formed of an elastic synthetic resin and is rotatably supported by a shaft 14a sandwiched between supporting members 13a and 13b.

As shown in FIGS. 2 (a) to (c), the gear 12 has a cylindrical rotation center portion 12b having a shaft hole 12a into which a shaft 14a is rotatably fitted, and an upper portion of the rotation center portion 12b. Has a small-diameter tooth portion 12c formed in
The large diameter tooth portion 12d is concentrically connected to the rotation center portion 12b by an elastic connection portion 12e formed between the inner circumference of the large diameter tooth portion 12d and the lower outer circumference of the rotation center portion 12b.

Explaining the structure of the elastic coupling portion 12e in more detail, protrusions 12f radially protruding at equal intervals of 120 ° are formed on the lower outer circumference of the rotation center portion 12b, and the projections 12f are sufficiently larger than the outer circumference of the rotation center portion 12b. Large-diameter tooth part 1 with inner diameter
On the inner circumference of 2d, projections 12g radially projected at equal intervals of 120 ° are formed. And the center of rotation 12b
The projection 12f of the tooth and the projection 12g of the large diameter tooth portion 12d are 60 °
The protrusions 12f and 12g, which are positioned in a displaced state and are displaced by 180 °, are connected by an arc-shaped rim 12h.

The gear 12 has a large-diameter tooth portion 12d whose pinion gear 1
The small-diameter tooth portion 12b is meshed with the first tooth and the supporting member 13
The large diameter tooth portion 15a of the gear 15 rotatably supported by the shaft 14b supported by a and 13b meshes with the gear 15 to reduce the rotation of the stepping motor 10.
Communicate to.

The large diameter tooth portion 12d of the gear 12 is the same module as the pinion gear 11, but the stepping motor 1
The distance L between the rotating shaft 10a and the shaft 14a of 0 is made slightly smaller than the sum of the radii of the large diameter tooth portions 12d of the pinion gear 11 and the gear 12, and the large diameter tooth portion 12d of the pinion gear 11 and the gear 12 is In the meshed state of the gear 12, the rim 12h of the gear 12 is deflected, and the large diameter tooth portion 12d becomes the pinion gear 11
Being pressed against. Therefore, in this meshed state, backlash, which is a play between tooth surfaces, is eliminated.

Since the backlash is eliminated, even if the rotation of the pinion gear 11 is uneven due to the step rotation of the stepping motor 10, the collision noise between the tooth surfaces is not generated, and even if there is no backlash, the rim 12h is elastically deformed to have a large diameter. Since the entire tooth portion 12d escapes, the teeth do not cling to each other and smooth movement is not hindered.

As described above, since the rim 12h as the elastic connecting portion 12e is interposed between the rotation center portion 12b and the large-diameter tooth portion 12d, it is not necessary to give elasticity to each tooth, which facilitates the manufacture. Since the teeth of the large-diameter tooth portion 12d are formed in the same manner as the teeth of a normal gear and have sufficient strength, a gear that can be used for wide range rotation transmission from low speed to high speed can be obtained.

In particular, according to the structure of the arc-shaped rim 12h described above, even if the gear has a small diameter, the length of each rim can be made large, and the deformation amount per unit length of the rim can be made small. The pressure contact force between the teeth is substantially uniform over the entire circumference, and smooth rotational drive is performed.

Further, although an example of use as a gear that transmits rotation of the stepping motor 10 that performs step operation is shown, the same effect can be obtained by using it as a gear that transmits continuous rotation.

[Effects] As described above, according to the present invention, the first tooth portion is constantly pressed against the teeth of the drive gear to eliminate backlash without impairing the smooth transmission of the driving force. Noise due to the abutment of the teeth involved is eliminated.

In addition, even if the gear has a small diameter, the length of each rim can be made large, and the amount of deformation per unit length of the rim can be made small, so that the pressure contact force between the teeth is the entire circumference of the first tooth portion. Is substantially uniform over the entire length, and smooth rotation driving force is transmitted from this point as well.

Further, it is very inexpensive, and it is possible to obtain a small-sized gear with high efficiency.

Furthermore, the elastic connecting portion that connects the rotation center portion and the first tooth portion is shared by all the teeth on the entire circumference of the first tooth portion, and it is not necessary to impart elasticity to each tooth.

Moreover, since the elastic coupling portion between the first tooth portion and the rotation center portion buffers the rotational force, the collision of the tooth surfaces when the driven gear is driven by the second tooth portion is also alleviated. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of use of the sound deadening gear according to the present invention, FIG. 2 is a view showing details of the sound deadening gear in FIG. 1, and FIGS. 3 and 4 are examples of conventional sound deadening gears, respectively. FIG. 10a ... Drive shaft, 11 ... Pinion gear (drive gear), 1
2 ... Silencer gear, 12b ... Rotation center part, 12c ... Small diameter tooth part (second tooth part), 12d ... Large diameter tooth part (first tooth part), 1
2e ... elastic connecting portion, 12h ... arc-shaped rim, 14 ... shaft,
15 ... Gear (driven gear).

Claims (1)

[Scope of utility model registration request] 1. A first tooth portion meshing with a drive gear and a second tooth portion meshing with a driven member, which are used to transmit the rotation of the drive gear to the driven member. A sound deadening gear, which is integrally formed with the second tooth portion and rotatably supported by a shaft, and concentrically connects the rotation center portion and the first tooth portion. Along with the elastic connecting portion, the elastic connecting portion is formed by an arc-shaped rim that connects the rotation center portion and the first tooth portion so as to relatively move in the circumferential direction and the radial direction by elastic deformation. 1 tooth portion and the elastic connecting portion are integrally formed of an elastic synthetic resin, and the axial distance between the rotary shaft of the drive gear and the shaft is equal to the radius of the drive gear and the first tooth portion. A sound deadening gear characterized by being slightly smaller than the sum.