JPH04113059A - Formed gear - Google Patents

Abstract

PURPOSE:To prevent the generation of a resonance sound, vibration and noise of a base, and periodic vibration and noise by forming a ring damper part from a synthetic resin softer than a disc gear body in the state where it is charged in a circular space between an inside disc part and a ring tooth form part. CONSTITUTION:When a partner gear 60 is rotated by a drive source, the driving force is transmitted from the partner gear 60 to a formed gear 10 through the gearing part of tooth form parts 13, 26 to rotate the formed gear 10. In this driving force transmission, a gearing shock and a vibration by mutual sliding are generated in both the tooth form parts 13, 26. The vibration generated in the ring tooth form part 13 is absorbed and damped by a soft resin ring damper part 21 interposed between the ring tooth form part 13 and an inside disc part 12. Thus, the ratio of the vibration transmitted to the whole formed gear 10 is sufficiently low, and a resonance sound by vibration of the whole formed gear 10 is hardly generated. By the same reason, the ratio of the vibration transmitted to a base 70 is also sufficiently low, and vibration and noise are hardly generated in the base 7.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is applicable to applications where the load is relatively thick (rotated at high speed), such as a drive gear for a tape take-up reel in a magnetic recording/reproducing device (VTR). The present invention relates to a molded gear used as a rotation transmission power transmission gear.

<Prior Art> A plan view of a gear transmission mechanism using conventional molded gears is shown in FIG. 7, and a partially cutaway side view thereof is shown in FIG.

The molded gear 50 is made of hard resin such as polyacetal, with a ring-shaped tooth profile 52 formed all around the outer periphery of a disc-shaped gear body 51, and a shaft insertion hole 53 formed in the center. It is integrally molded.

Similarly, the mating gear 60 has a ring-shaped toothed portion 62 on the outer peripheral portion of the disc-shaped gear main body 61, and has a shaft insertion hole 63 in the center portion.

The shaft insertion hole 53 of the molded gear 50 is rotatably fitted (loosely fitted) to a support shaft 71 that stands vertically on the base 70 . The base 70 is spaced apart from the support shaft 71 by a certain engagement distance.
A support shaft 72 is vertically disposed on the support shaft 72, and the shaft insertion hole 53 of the mating gear 60 is rotatably fitted (loosely fitted) into the support shaft 72. 62 are engaged with each other.

When the mating gear 60 is rotated by a drive source (not shown), driving force is transmitted from the mating gear 60 to the forming gear 50 through the meshing portions of the toothed portions 52 and 62, and the forming gear 50 is rotated.

When this driving force is transmitted, vibrations are generated in both toothed portions 52, 62 due to impact when they mesh and due to mutual sliding. Since the molded gear 50 is an integrally molded product, the vibration generated by the toothed portion 52 is transmitted to the entire molded gear 50 and generates resonance sound.

Further, the vibration is transmitted to the base 70 via the support shaft 71,
Undesirable vibrations and noise occur in the base 70.

If the entire molded gear 50 is molded from a soft resin such as nylon or polyester, vibrations due to meshing impact can be alleviated, but the amount of deformation of the tooth profile portion 52 due to the transmitted load will increase, and vibrations due to mutual sliding will increase. increase

FIG. 9 shows another conventional example that solves this problem.
There is a shaped gear 80 as shown in FIG.

This molded gear 80 includes an inner disk portion 81, a ring-shaped toothed portion 82 concentrically arranged outside the inner disk portion 81 with a space therebetween, and a plurality of inner disk portion 81 and ring-shaped toothed portions 82 in the circumferential direction. It has spoke-like connecting portions 83 that are integrally connected along the radial direction at certain points, and is integrally molded from hard resin.

A shaft insertion hole 84 is formed in the center of the inner disk portion 81. A portion surrounded by the inner disk portion 81, the ring-shaped toothed portion 82, and a pair of circumferentially adjacent spoke-shaped connecting portions 83 forms an arcuate space 85.

When vibrations due to meshing impact or mutual sliding occur in the tooth profile portion 82 at the meshing portion with the mating gear 60, the vibrations are damped by the plurality of spoke-shaped connecting portions 83, and resonance noise is generated due to the vibration of the entire shaped gear 80. The generation of unnecessary vibrations and noise of the base 70 due to vibration transmission through the support shaft 71 are suppressed.

<Problems to be Solved by the Invention> However, since the inner disk portion 81 and the ring-shaped toothed portion 82 are connected at multiple locations by the spoke-like connecting portions 83, the ring-shaped toothed portion 82 may be deformed due to the transmitted load. The amount of deformation is large at the location corresponding to the arcuate space 85 and becomes small at the location corresponding to the spoke-shaped connecting portion 83, resulting in a state in which the amount of deformation alternately increases and decreases, resulting in periodic vibrations and noise. It turns out that a new problem arises.

The present invention was devised in view of these circumstances, and does not generate resonance sound or vibration/noise of the base.
The object of the present invention is to provide a molded gear that does not generate periodic vibrations or noise.

<Means for Solving the Problems> In order to achieve the above object, the present invention proposes two molded gears having the following configurations.

[+] The first molded gear according to the present invention includes a disc-shaped gear main body and a ring-shaped buffer part, and the disc-shaped gear main body includes:
An inner disk portion having a shaft insertion hole formed in the center portion, a ring-shaped toothed portion concentrically arranged outside the inner disk portion with a space between them, and the inner disk portion and the ring-shaped toothed portion. and a spoke-shaped connecting part that integrally connects the spokes along the radial direction at multiple locations in the circumferential direction, and the entire ring-shaped buffer part is integrally molded from a hard resin, and the ring-shaped buffer part is
It is molded from a synthetic resin that is softer than the disc-shaped gear body and fills a plurality of arcuate spaces between the inner disc part and the ring-shaped toothed part.

[11] The second molded gear according to the present invention has an inner disk portion, a ring-shaped toothed portion, and a ring-shaped buffer portion, and the inner disk portion has a shaft insertion hole formed in a center portion. The ring-shaped tooth-shaped part is molded from a hard resin and is arranged concentrically on the outside of the inner disk part, and the ring-shaped tooth-shaped part is molded from a hard resin in a state in which teeth,
The annular space between the inner disc part and the ring-shaped tooth profile part is filled with a synthetic resin that is softer than the inner disc part and the ring-shaped tooth profile part, and the inner disc part and the ring-shaped tooth profile part are are integrally connected.

<Function> [i] According to the first molded gear according to the present invention, vibrations generated in the ring-shaped tooth profile due to meshing with the mating gear or mutual sliding are caused by vibration between the ring-shaped tooth profile and the inner disc part. Since the vibration is absorbed and attenuated by the ring-shaped buffer made of soft resin interposed in the arc-shaped space between the two, the vibration becomes difficult to be transmitted to the entire molded gear.

In addition, since the arc-shaped space between the inner disk part and the ring-shaped tooth profile between adjacent spoke-shaped connecting parts in the circumferential direction is filled with the ring-shaped buffer part, the amount of deformation of the ring-shaped tooth profile due to the transmitted load is is approximately the same throughout the circumferential direction.

[ii] According to the second molded gear according to the present invention, there is no structure in which the inner disc part and the ring-shaped tooth profile part are connected by the spoke-like connecting part in the case of the first molded gear, and the inner disc part There is a continuous annular space around the entire circumference between the and the ring-shaped tooth profile, and the entire annular space is filled with a ring-shaped buffer made of soft resin, which prevents the transmission of vibration to the entire molded gear. The suppressing function is more effectively exhibited, and the amount of deformation of the ring-shaped tooth profile due to the transmitted load is more precisely equalized.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

Brush construction A The first embodiment is an example of the first molded gear according to the present invention, and a plan view of a gear transmission mechanism using this molded gear is shown in FIG. 1, and an enlarged part thereof. A side view of the fracture is shown in FIG.

The molded gear 10 of the first embodiment has a hard disk-shaped gear body 1.
1 and a soft ring-shaped buffer section 21.

As shown in FIG. 3(a), the disc-shaped gear main body 11 includes an inner disc part 12 and a ring-shaped toothed part 13 concentrically arranged outside the inner disc part 12 with a space in between. and a plurality of spoke-like connecting portions 14 that integrally connect the inner disk portion 12 and the ring-shaped toothed portion 13 in the radial direction at multiple locations equally divided in the circumferential direction, and the entirety thereof is made of polyacetal or the like. It is integrally molded from hard resin. A shaft insertion hole 15 is formed in the center of the inner disk portion 12.

At the stage of molding this disc-shaped gear body 11, the space between the inner disc part 12 and the ring-shaped tooth profile part 13 is divided into a plurality of arc-shaped spaces 16 partitioned by spoke-shaped connecting parts 14.
It becomes.

Then, as shown in FIG. 3(b), a ring-shaped buffer part 21 made of soft resin is outsert-molded to the disc-shaped gear body 11 in a state that fills the plurality of arc-shaped spaces 16, and This constitutes a molded gear 10 which is a completed product.

The ring-shaped buffer section 21 literally has a ring shape in which the entirety is a closed loop, but if you look at the detailed structure from the cross-sectional shape, you can see that the ring-shaped buffer section 21 has a plurality of arc-shaped portions 2 in each arc-shaped space 16.
2, one front side ring-shaped flange part 23, and one back side ring-shaped flange part 24 are integrated.

The arcuate portion 22 is filled in the inner cup of each arcuate space 16 and connects the outer circumferential surface of the inner disc portion 12, the inner circumferential surface of the ring-shaped toothed portion 13, and one of the spoke-shaped connecting portions 14. and the side surface of the other spoke-like connecting portion 14. The front side ring-shaped flange portion 23 is closely integrated with the surface of each of the plurality of circular arc portions 22, the surface near the outer periphery of the inner disk portion 12, and the surface near the inner periphery of the ring-shaped toothed portion 13. There is. The back side ring-shaped flange portion 24 is connected to the back surface of each of the plurality of arcuate portions 22 , the back surface near the outer periphery of the inner disk portion 12 , and the ring-shaped toothed portion 13 .
It is in close contact with the back surface near the inner periphery.

The soft resin constituting the ring-shaped buffer section 21 is a polyester resin containing an elastomer having rubber-like elasticity (
For example, Perbrene (trade name) is suitable.

In the molded gear 10 configured as described above, as shown in FIG. (play fit). The base 7 is spaced apart from the support shaft 71 by a certain engagement distance.
A support shaft 72 is vertically placed at 0, and a mating gear 60 is attached to this support shaft 72.
The shaft insertion hole 63 of the molded gear 10 is rotatably fitted into the ring-shaped toothed portion 13 of the molded gear 10 and the ring-shaped toothed portion 6 of the mating gear 60.
2 are engaged.

When the mating gear 60 is rotated by a drive source (not shown), driving force is transmitted from the mating gear 60 to the forming gear 10 through the meshing portions of the toothed portions 13.62, and the forming gear 10 is rotated. When this driving force is transmitted, vibrations are generated in both toothed portions 13.62 due to the impact when they mesh and due to mutual sliding.

However, the vibration generated by the ring-shaped toothed portion 13 is absorbed and attenuated by the ring-shaped buffer portion 21 made of soft resin and interposed between the ring-shaped toothed portion 13 and the inner disk portion 12. Therefore, the rate at which the vibrations are transmitted to the entire molded gear 10 is sufficiently low (there is almost no resonance sound caused by the vibration of the entire molded gear 10. For the same reason, the rate at which the vibrations are transmitted to the base 70 is also low. Low enough, base 7
Even at 0, almost no vibration or noise occurs.

Further, although the ring-shaped tooth profile 13 is deformed by the transfer load applied from the mating gear 60 to the ring-shaped tooth profile 13 of the molded gear 10, the gap between the ring-shaped tooth profile 13 and the inner disc part 12 is In the case of , there was only a spoke-like connection and most of the rest was pure space, whereas
In this embodiment, the arc-shaped space 1 other than the spoke-shaped connecting portion 14
6 is entirely filled with the arc-shaped portion 22 of the ring-shaped buffer portion 21, the amount of deformation due to the transmitted load itself is small, and moreover, it is distributed almost uniformly over the entire circumferential direction. Therefore, even though the spoke-shaped connecting portions 14 are locally present, periodic vibrations and noise are suppressed from occurring.

The parts that make up such a silent, low-vibration molded gear with zero weight are the inner disk portion 12. Since there are only two parts, the disc-shaped gear body 11 in which the ring-shaped tooth profile part 13 and the spoke-shaped connecting part 14 are integrally molded, and the ring-shaped buffer part 21, the molded gear 10 can be manufactured at relatively low cost. I can do it.

The second embodiment is an example of the second molded gear according to the present invention, and a plan view of a gear transmission mechanism using this molded gear is shown in FIG. A side view of the fracture is shown in FIG.

The molded gear 30 of the second embodiment is composed of three parts: a hard inner disk part 31, a hard ring-shaped toothed part 32, and a soft ring-shaped buffer part 33.

The inner disk portion 31 is molded from a hard resin such as polyacetal with a shaft insertion hole 34 formed in the center portion. The ring-shaped toothed portion 32 is also molded from a hard resin such as polyacetal.The inner disk portion 31 and the ring-shaped toothed portion 32 may be molded simultaneously in one mold or in separate molds. They may be individually molded using a mold.

In this way, first, the inner disk portion 31 and the ring-shaped toothed portion 32 are
1 for outsert molding.
In one mold, the ring-shaped toothed part 32 is set concentrically on the outside of the inner disc part 31, and after the mold is clamped, an annular space 35 between the inner disc part 31 and the ring-shaped toothed part 32 is set.
(cavity) is filled with soft resin such as polyester resin containing elastomer and solidified to form a ring-shaped buffer part 3.
3 is outsert molded to obtain a completed molded gear 30.

In the case of this embodiment, the inner disk portion 31 and the ring-shaped toothed portion 32
The ring-shaped buffer section 33 and the ring-shaped buffer section 33 have the same thickness, and the inner circumferential surface of the ring-shaped buffer section 33 is attached to the outer circumferential surface of the inner disk section 31, and the outer circumferential surface is attached to the inner circumferential surface of the ring-shaped toothed section 32, respectively. Closely integrated. Further, there is no spoke-like connection part as in the first embodiment, and the annular space 35 between the inner disk part 31 and the ring-shaped toothed part 32 is formed by the ring-shaped buffer part 33.
is completely filled in. In order to emphasize this state, the ring-shaped buffer portion 33 is hatched in FIG. 4.

Molded gear 30 and mating gear 6 configured as described above
The structure of attaching the base plate 70 to the base 70 is the same as that shown in FIG. 1, so a description thereof will be omitted.

When transmitting driving force from the mating gear 60, both toothed portions 32.
Vibrations caused by the meshing impact and mutual sliding between the rings 62 are applied to the ring-shaped tooth profile 32, but this vibration is completely buried between the ring-shaped tooth profile 32 and the inner disc part 31 over the entire circumference. The ring-shaped buffer section 33 ensures absorption and attenuation.

Therefore, the generation of resonance noise due to the entire vibration of the molded gear 30 and the generation of vibrations and noise in the base 70 are reliably prevented.

In addition, the deformation of the ring-shaped tooth profile portion 32 due to the transmitted load is sufficiently suppressed, and even the slight deformation is uniformly distributed over the entire circumferential direction due to the presence of the ring-shaped buffer portion 33, resulting in periodic vibrations and noise. can be reliably prevented from occurring.

In addition, in producing a molded gear in which the ring-shaped tooth profile part and the inner disk part are not connected by the spoke-shaped connection part, the first
In the same way as explained in FIGS. 3(a) and 3(b) in the embodiment, as shown in FIG. A disc-shaped gear main body 37 is integrally molded, and a ring-shaped buffer part 3 is attached to this.
3 may be outsert-molded, and then the spoke-like connecting portions 36 may be cut by punching a hole 38 in the ring-shaped buffer portion 33 at the location of the spoke-like connecting portion 36 using a press or the like.

That is, by using the molded gear of the first embodiment as a semi-finished product and cutting the spoke-like connecting parts thereof, the second embodiment is made.
This is the molded gear 30 of the embodiment.

In addition, in the gear transmission mechanism according to each of the above embodiments, the shaft insertion holes 15, 34 of the molded gear 10.30 are rotatably fitted (loosely fitted) to the support shaft 71, but the use of the molded gear As a form, the rotating shaft may be inserted and fixed into the shaft insertion hole, and the rotating shaft integrated with the molded gear may be supported by a bearing.

<Effects of the Invention> ■ According to the first molded gear according to the present invention, the ring-shaped buffer part made of a soft resin interposed in the arc-shaped space between the ring-shaped tooth profile part and the inner disc part Because it absorbs and damps vibrations generated in the ring-shaped tooth profile due to meshing impact with gears and mutual sliding, soft resin not only suppresses resonance noise caused by vibration of the entire molded gear and vibrations and noise of the base etc. The deformation of the ring tooth profile due to the transmitted load can be made almost uniform by the ring-shaped buffer section made of aluminum, and even when there are multiple circumferentially spoke-shaped connecting parts connecting the inner disk part and the ring tooth profile. However, it is also possible to suppress the generation of periodic vibrations and noise.

In addition, the number of parts is two: a disc-shaped gear body made of a hard resin, in which an inner disc part, a ring-shaped tooth profile part, and a spoke-shaped connecting part are integrally molded, and a ring-shaped buffer part made of a soft resin.
Since only the parts are used, the molded gear can be manufactured relatively easily, and a molded gear with low noise and low vibration can be provided at a cost-effective manner.

■ According to the second molded gear according to the present invention, the spoke-shaped connecting portion is eliminated, and the entire annular space that is continuous over the entire circumference between the inner disk portion and the ring-shaped tooth profile portion is made of a soft resin ring-shaped Since it is filled with a buffer section, it is possible to reliably prevent resonance noise of the entire molded gear, vibration of the base, etc., and the generation of noise, and the amount of deformation of the ring-shaped tooth profile due to the transmitted load can be equalized with high precision, making it possible to reduce the periodicity. The generation of vibrations and noise can be reliably prevented.

[Brief explanation of the drawing]

Figures 1 to 3 relate to the first embodiment of the present invention.
The figure is a plan view of a gear transmission mechanism using the shaped gear of the first embodiment, FIG. 2 is an enlarged side view of the gear transmission mechanism, partially broken away, and FIG. 3 is an explanatory view of the procedure for manufacturing the shaped gear. 4 to 6 relate to the second embodiment, FIG. 4 is a plan view of a gear transmission mechanism using molded gears of the second embodiment, and FIG. 5 is an enlarged partially cutaway side view of the gear transmission mechanism. , FIG. 6 is an explanatory diagram of the procedure for manufacturing the molded gear. Further, FIG. 7 is a plan view of a gear transmission mechanism using conventional molded gears, and FIG. 8 is a partially cutaway side view thereof. FIG. 9 is a plan view of another conventional example which is an improvement on the molded gear shown in FIG. 7, and FIG. 10 is a partially cutaway side view thereof. 10... Molded gear, 11... Disc-shaped gear body, 12
...Inner disc part, 13...Ring-shaped tooth profile part, 14.
・Spoke-like connection part, I5 ・Shaft insertion hole, 16 ・・
- Arc-shaped space, 21... ring-shaped buffer section, 30...
Molded gear, 31...Inner disc part, 32...Ring-shaped tooth profile part, 33...Ring-shaped buffer part, 34...Shaft insertion hole, 35...Annular space

Claims (2)

[Claims] (1) Disc-shaped gear body (11) and ring-shaped buffer part (2)
1), the disc-shaped gear body (11) has a shaft insertion hole (
15), a ring-shaped toothed portion (13) concentrically arranged outside the inner disk portion (12) with a space therebetween, and the inner disk portion (12). (12) and a ring-shaped toothed part (13) are integrally connected along the radial direction at multiple circumferential locations, and the entire spoke-shaped connecting part (14) is integrally molded from hard resin. The ring-shaped buffer section (21) is connected to the inner disk section (12).
) and the ring-shaped tooth profile (13), filling the plurality of arcuate spaces (16) between the disc-shaped gear body (11) and the ring-shaped tooth profile (13).
A molded gear characterized by being molded from a softer synthetic resin. (2) Inner disc part (31) and ring-shaped tooth profile part (32)
and a ring-shaped buffer part (33), the inner disc part (31) is molded from a hard resin with a shaft insertion hole (34) formed in the center part, The ring-shaped toothed portion (32) is molded from hard resin and is arranged concentrically on the outside of the inner disk portion (31), and the ring-shaped buffer portion (33) is formed from a hard resin. Part (31
) and the ring-shaped tooth profile (32).
These inner disk part (31), ring-shaped tooth profile part (32)
A molded gear made of a synthetic resin filled and solidified which is softer than the above molded gear, and which integrally connects an inner disk portion (31) and a ring-shaped toothed portion (32).