JP3184615B2 - transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission having at least a pair of gears inside a case, and more particularly to a transmission which reduces noise generated by meshing of gears.

[0002]

2. Description of the Related Art The noise of a transmission having a gear therein is mainly a noise caused by meshing of the gear. Conventionally, as a measure to reduce noise due to meshing of the gears,
(1) Reduce the excitation force due to gear engagement, (2)
Techniques have been proposed to make it difficult for the vibration of the gear to propagate to the case. As this technique, for example,
No. 0-98245.

The measures (1) and (2) are important as appropriate. However, when the power transmitted by the gears is large, or when the precision of the gears reaches the limit and cannot be increased any more, etc.
There are many cases where there is a limit to improving the gears themselves. In such a case, the case must be soundproofed.

As a soundproofing measure for the case, there is a technique described in, for example, Japanese Utility Model Laid-Open Publication No. Sho 61-73869. This covers the inside of the case with a sound insulating plate and forms a number of pockets. However, this conventional technique does not have a role of isolating a specific frequency, but rather attempts to widely isolate a sound in a relatively high frequency band. If it is attempted to reduce the number, it is not enough.

[0005]

However, none of the above-mentioned prior arts takes into account reduction of low-frequency noise. Therefore, the sound pressure inside the case is high,
In addition, there is a problem that it is not possible to sufficiently reduce a musical sound having a relatively low frequency (1 kHz or less) which is difficult to be sound-insulated by a sound absorbing material or the like.

In other words, in the prior art, it is relatively easy to reduce high frequency noise, but it is difficult to reduce high frequency noise in which a sharp peak appears in low frequency noise. there were. The reason is that the wavelength of the high-frequency sound is short, but the wavelength of the low-frequency sound is long, so that it is necessary to increase the thickness of the sound insulation layer in the sound insulation device. If the sound insulation layer is thick, the size of the sound insulation device increases, so that it cannot be used in a transmission or the like that must be installed in a limited space inside the case, and there is also a problem that equipment costs increase.

An object of the present invention is to provide a transmission capable of effectively reducing noise at a meshing frequency of a gear provided inside a case, reducing noise and avoiding an increase in size.

[0008]

According to one aspect of the present invention, there is provided a transmission having at least a pair of gears meshing with each other inside a case. Rutotomoni provided intermeshing co-sounding muffler at the corners of the upper than the position, provided an oil reservoir below the position of the gear.

The resonance type silencer adjusts the center frequency of the resonance to the meshing frequency of the gear and uses two side walls forming a corner inside the case as side walls of the muffler. In addition, another wall surface of the silencer is formed on a side sandwiched between the two side walls of the corner portion to form a triangular cross section.

According to a second aspect of the present invention, in a transmission having at least a pair of gears meshing with each other inside a case, a resonance type is provided at a corner above the meshing position of the gears inside the case. With a muffler,
An oil reservoir was provided below the position of the gear.

The resonance type silencer adjusts the center frequency of the resonance to the meshing frequency of the gear and has an elastic member between a wall surface inside the case and a wall surface constituting the muffler. Interposed and fixed.

[0012]

[0013]

[0014]

[0015]

According to the first aspect of the present invention, a resonance type silencer is provided.
Noise generated by gear meshing
Of specific frequencies of the
It is possible to reduce noise .

Further, the center frequency of the resonance before Symbol resonance type silencer, since in accordance with the meshing frequency of the gear, the noise generated by the meshing of the gear can be greatly reduced.

Further, two side walls constituting a corner portion inside the case are used as side walls of a muffler, and another side of the muffler is sandwiched between the two side walls of the corner portion. Since the wall surface is formed and the silencer has a triangular cross section, the silencer can be reduced in size and further space saving can be achieved. In addition, the components of the silencer are reduced,
Cost can be reduced.

Next, in the invention according to claim 2, because of the use of the invention as well as resonance-type silencer according to claim 1 above, certain of the noise generated by the meshing of the gears The frequency sound can be reduced, and the noise transmitted to the outside of the case can be reduced.

Further, since the center frequency of the resonance in the resonance type silencer is set to the meshing frequency of the gears, noise generated by meshing of the gears is greatly reduced. can do.

Furthermore, since the interposed elastic member securing the silencer between the wall surface constituting the muffler and the interior wall surface of the casing by the elastic member, transmitted from the case to the muffler Vibration can be absorbed and alleviated, and a reduction in the noise reduction function can be prevented even when the thickness of the components of the muffler is reduced.

[0021]

[0022]

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

1 to 7 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of the entire transmission, and FIG.
FIG. 3 is a perspective view of a resonance type silencer (hereinafter referred to as “resonance type silencer”) used in the embodiment of FIG. 3, FIG. 3 is a diagram illustrating the principle of a Helmholtz type resonator, and FIG. FIG. 5 is a diagram showing the noise reduction characteristics of the resonance type silencer used in the first embodiment, and FIG. 6 is a diagram showing the noise of the transmission in the first embodiment. FIG. 7 is a diagram showing an example of actual measurement of the sound reduction effect in the first embodiment.

In the first embodiment shown in these figures, FIG.
As shown in FIG. 5, the input shaft 1 and the output shaft 2 are attached to the case 5 in directions orthogonal to each other.

The input shaft 1 is supported by a case 5 via radial bearings 6 and 7. One end of the input shaft 1 is connected to a rotary drive source (neither is shown) such as an electric motor or a turbine via a coupling, and a small bevel gear 3 is fixed to the other end.

One end of the output shaft 2 is supported by a case 5 by a radial bearing 8, and the other end is supported by the case 5 via a radial bearing 9 and a thrust bearing 10.

One end of the output shaft 2 is connected to a load (not shown) such as a pump via a coupling. Further, a large bevel gear 4 meshing with the small bevel gear 3 is fixed to the output shaft 2.

Below the inside of the case 5, an oil reservoir 11 and an oil pump 13 are provided. The oil sump 11 contains a lubricating oil 12. The oil pump 13 is drivingly connected to the output shaft 2 via a gear train 14, and serves as a pair of a small bevel gear 3 and a large bevel gear 4, radial bearings 6 to 9, and a thrust bearing 10. Is supplied.

The above inside the casing 5, as shown in FIG. 1, a second fruit resonance type silencer 15 is described below
As in the embodiment, a plurality of the members are provided via an elastic member (not shown ). Each resonance type silencer 15 is, as shown in FIG.
The case 5 is formed into a pentahedron having a triangular cross section that fits into a corner portion inside the case 5, and a cavity 16 is formed inside. In addition, one of the peripheral walls of the resonance type silencer 15 is provided with a pipe line 17 for entering and exiting air. Further, as can be seen from FIG. 1, the resonance type silencer 15 is attached to an upper corner portion inside the case 5 with the pipe line 17 facing the central axis inside the case 5. The reason why the resonance type silencer 15 is attached to the upper corner portion inside the case 5 is that the corner portion inside the case 5 including the case where air column resonance occurs due to the balance between the dimensions of the case 5 and the meshing frequency of the gears. , The oil pressure is particularly high, oil is hardly applied to the resonance type silencer 15, and space can be saved.

As described above, one cavity 16
The resonance type silencer 15 configured to have the air inlet / outlet pipe 17 belongs to the Helmholtz type resonator shown in FIG. In this Helmholtz resonator, the resonance frequency f
₀ is substantially determined by the volume V of the cavity, the cross-sectional area S of the pipeline, the length l of the pipeline, and the sound speed c, and is obtained by the following _{equation (} 1).

[0031]

(Equation 1)

From the above equation (1), V, S, and l are adjusted to determine the frequency to be resonated. In the first embodiment of the present invention, as shown in FIG.
Although the thickness is taken as the thickness of the wall plate constituting 5, a new pipe may be added as shown in FIG.

In the first embodiment, the center frequency of the resonance type silencer 15 is mainly adjusted to the meshing primary component of the small bevel gear 3 and the large bevel gear 4 shown in FIG.

Next, the operation of the transmission according to the first embodiment will be described.

When a rotary drive source such as a motor or a turbine is driven, the rotation is transmitted to the input shaft 1 via the coupling, and then transmitted from the small bevel gear 3 to the large bevel gear 4 to rotate the output shaft 2. As a result, the rotation of the output shaft 2 is decelerated with respect to the rotation of the input shaft 1, and the rotation direction is changed and transmitted to the output shaft 2. The rotation of the output shaft 2 is transmitted to the load side via the coupling, and drives a load such as a pump.

At this time, the small bevel gear 3 and the large bevel gear 4 mesh with each other, so that a collision sound and a vibration sound are generated. As shown in FIG. 4, the main component of the collision sound and the vibration sound is one of the meshing frequency of the gears (the number of rotations of the input shaft 1 × the number of teeth of the small bevel gear 3).
The next component. The sound generated in the vicinity of the gear pair increases the sound pressure inside the case 5 and penetrates outside the case 5, resulting in harsh noise. This transmitted sound is
By increasing the thickness of the plate 5, sound insulation is performed to some extent, but the vibration transmitted from the gear pair causes the case 5 itself to vibrate, thereby reducing the sound insulation effect. Therefore, reducing the internal sound of the case 5 is important for reducing noise.

Therefore, in the first embodiment, a plurality of resonance silencers 1 are provided in the upper corner portion inside the case 5.
5 are provided. The center frequency of the resonance of the resonance type silencer 15 is mainly adjusted to the primary component of the meshing frequency of the gear, and the noise reduction characteristics are as shown in FIG.

As a result, as shown in FIG. 6, since the sound pressure of the gear meshing frequency component, which is the main peak of the sound pressure, is greatly reduced, the sound pressure inside the case 5 is reduced. Therefore, the transmitted sound from the case 5 is also reduced.

FIG. 7 shows the effect of the resonance type silencer 15. When the noise level was examined by changing the number of rotations of the gear pair, when the center frequency of the resonance type silencer 15 was set near the meshing frequency of the gear, the reduction amount of the sound pressure level of the meshing frequency component became particularly large. You can see that there is. As a result, the overall noise level is also reduced.

Further, in the first embodiment, since the resonance type silencer 15 is provided at the corner where the sound pressure becomes highest inside the case 5, the sound pressure can be reduced more efficiently, and the noise can be reduced. Can be reduced.

Further, since the resonance type silencer 15 is formed in a shape that fits into the inside corner of the case 5, the space at the corner of the case 5 can be effectively used to save space. it can.

In the first embodiment, the resonance type silencer 15 is not limited to having one air inlet / outlet pipe 17 but may be provided in plural. Further, a hole for draining oil may be provided at the bottom of the resonance type silencer 15. Further, if there is another frequency component larger than the primary component, such as the secondary component of the gear meshing frequency shown in FIG. 4, the resonance center frequency of the resonance type silencer 15 is adjusted to the large frequency component. You may.

FIG. 8 shows a second embodiment of the present invention and is a partial perspective view of a resonance type silencer.

The second embodiment shown in FIG. 8 differs from the first embodiment in the shape of the resonance type silencer.

That is, in the second embodiment, the resonance type silencer 18 is formed by combining the plate member 19 into an L-shape having the same shape as the corner portion inside the case 5. The plate member 19 is provided with a large number of holes 20 for air inflow and outflow regularly.

The resonance type silencer 18 is
Is arranged at a gap h between the inside of the case 5 and the side wall of the case 5 and is fixed with an elastic member 21 interposed therebetween.

In the second embodiment, the resonance frequency f ₀ of the resonance type silencer depends on the hole diameter d, the hole pitch p, the plate thickness L ₀ , and the gap h between the side wall of the case and the plate. , And the following equation (2).

[0048]

(Equation 2)

Here, L = L ₀ +0.8 da = π / 4d ² V = p ² h. The other specifications are the same as those in the above-described equation (1).

According to the second embodiment as well, the sound pressure inside the case 5 can be reduced, and the transmitted sound from the case 5 can be reduced. The other configuration and operation of the second embodiment are the same as those of the first embodiment.

Next, FIG. 9 shows a third embodiment of the present invention and is a perspective view of a main part.

In the third embodiment shown in FIG. 9, ring-type silencers 15a, 15b, and 15c are vertically overlapped on a corner portion inside the case 5 via an elastic member (not shown). Is fixed.

The resonance type silencers 15a and 15c are provided with a single air passage 17 and have the same resonance center frequency. On the other hand, the resonance type silencer 1
5b is provided with two pipes 17 arranged side by side in the horizontal direction, and has a different sectional area S. Therefore, the resonance type silencer 15b is different from the other resonance type silencers 15a and 15c.
The center frequencies of resonance are different.

In the third embodiment, as described above, since a plurality of resonance silencers having different resonance center frequencies are provided, a sound having a large peak noise level other than the primary component of the gear meshing is provided. Even if there is, the sound pressure can be reduced and the sound transmitted from the case 5 to the outside can be reduced. If there is a second or third peak or the like in addition to the frequency component, it is possible to set a muffling range for the second or third peak or the like. as a result,
Not only the meshing frequency component of the gear in case 5 but also
Noise such as the second or third peak can be reduced in the same manner.

Further, in the third embodiment, the resonance frequency of the resonance type silencer is changed by changing the cross-sectional area S by the number of the conduits 17, but by changing the other dimensions, the resonance is reduced. The frequency may be changed.

Further, in the third embodiment, FIG.
The resonance type silencer 18 of the second embodiment shown in FIG.

The other structure and operation of the third embodiment are the same as those of the first embodiment.

Next, FIG. 10 shows a fourth embodiment of the present invention and is a cross sectional view of a main part.

In the fourth embodiment shown in FIG. 10, a resonance type silencer is constituted by utilizing the side wall of the corner portion inside the case 5.

That is, the plate member 23 having the air inlet / outlet pipe 24 is attached to the side sandwiched between the side walls 5a and 5b of the corner portion inside the case 5.
The resonance type silencer 22 having a triangular cross section is formed by the cavity 5 and the plate member 23. Both ends of the plate member 23 are fixed to the side walls 5a and 5b of the case 5 by welding 26 or the like.

As a result, in the fourth embodiment, the components of the resonance type silencer can be saved, and the cost can be reduced.
It is possible to further reduce the size of the resonance type silencer.

The other structure and operation of the fourth embodiment are the same as those of the first embodiment.

FIG. 11 shows a fifth embodiment of the present invention, and is a cross sectional view of a main part.

In the fifth embodiment shown in FIG. 11, the resonance type silencer 15 is fixed to a corner portion inside the case 5 via an elastic member 27.

As described above, in the fifth embodiment, the elastic member 27 is provided between the wall surface of the case 5 and the wall surface of the resonance type silencer 15.
As a result, the vibration transmitted from the case 5 to the resonance type silencer 15 can be absorbed and mitigated by the action of the elastic member 27, so that the noise can be reduced even if the plate thickness of the components of the resonance type silencer 15 is reduced. The function can be prevented from lowering and noise can be reduced.

The other structure and operation of the fifth embodiment are the same as those of the first embodiment.

In each of the embodiments of the present invention, the pair of gears is not limited to the bevel gear shown in FIG. 1, but may be applied to, for example, a spur gear. .

[0068]

According to the invention described in claim 1 of the present application described above, according to the present invention, the inside of the case, less engaged with each other
In a transmission provided with a pair of gears,
In the corners above the meshing position of the gears, the resonance type
The silencer is provided, and the oil pool is formed below the position of the gear.
Provided, especially at corners of cases where sound pressure is high.
Sound can be produced and silencing can be effectively performed. Ma
In addition, the oil scattered by the rotation of the gears adheres to the silencer and is
It is possible to prevent the characteristics of the sound device from changing .

[0069] Further, the center frequency of the resonance in co-sounding muffler, since in accordance with the meshing frequency of the gear, the noise of the frequency components generated by the meshing of the gear can be greatly reduced.

[0070] Furthermore, the two side walls constituting the corner portion of the inside of the case used as the side wall of the silencer, the side sandwiched two side walls of the corner portion, silencer other Since the wall surface is formed and the silencer has a triangular cross section, the silencer can be reduced in size and further space saving can be achieved. In addition, the components of the silencer are reduced,
Cost can be reduced.

Next, according to the invention described in claim 2 of the present application, the inside of the case like the invention described in claim 1 above, in the transmission provided with at least a pair of gears meshing with each other, A resonance type silencer is provided at a corner above the meshing position of the gears inside the case, and an oil reservoir is provided below the position of the gears, so that noise is reduced particularly at corners of the case where the sound pressure is high. Can be effectively performed. Further, it is possible to prevent the oil scattered due to the rotation of the gear from adhering to the muffler and changing the characteristics of the muffler.

Further, since the center frequency of resonance in the resonance type silencer is matched with the meshing frequency of the gears as in the first aspect of the present invention, noise of frequency components generated by meshing of the gears is greatly reduced. Can be reduced.

[0073] Further, since the fixing elastic member to silencer interposed between the wall surface constituting the internal wall surface and muffler before SL case, by the elastic member, the muffler from the case can vibration transmitted by absorption relaxation, it is also possible to prevent a reduction in the noise reduction function by reducing the thickness of the muffler component.

[0074]

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention and is a longitudinal sectional view of an entire transmission.

FIG. 2 is a perspective view of a resonance type silencer used in the first embodiment.

FIG. 3 is a diagram illustrating the principle of a Helmholtz resonator to which the resonance silencer shown in FIG. 2 belongs.

FIG. 4 is a diagram illustrating an example of a relationship between transmission noise and frequency.

FIG. 5 is a diagram illustrating a sound reduction characteristic of the resonance type silencer used in the first embodiment.

FIG. 6 is a diagram illustrating a frequency analysis result of noise of the transmission according to the first embodiment.

FIG. 7 is a diagram illustrating an actual measurement example of a sound reduction effect in the first embodiment.

FIG. 8 shows a second embodiment of the present invention, and is a partial perspective view of a resonance type silencer.

FIG. 9 shows a third embodiment of the present invention, and is a perspective view of a main part.

FIG. 10 shows a fourth embodiment of the present invention and is a cross-sectional view of a main part.

FIG. 11 shows a fifth embodiment of the present invention and is a cross-sectional view of a main part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input shaft of a transmission, 2 ... Output shaft, 3 ... Small bevel gear, 4
... large bevel gear, 5 ... case, 15 ... resonance type silencer, 16 ...
Cavity of the resonance type silencer, 17 ... a pipe for the air in and out, 18
... Resonant silencer, 19 ... Plate material forming the resonant silencer, 20 ... Hole for air in / out, h ... Gap between the side wall of the case and the resonant silencer, 21 ... Resonant type with the side wall of the case Elastic members interposed between the silencers, 15a to 15c ... resonant silencers having different resonance center frequencies, 5a, 5b ... side walls of corners inside the case, 22 ... resonant silencers, 23
... A plate material constituting the resonance type silencer, 24... A conduit for air inflow and outflow of the resonance type silencer, 25... A cavity, 26... An elastic member interposed between the side wall of the case and the resonance type silencer.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-26598 (JP, A) JP-A-3-276841 (JP, A) JP-A-2-139355 (JP, U) JP-A-2-139355 96023 (JP, U) Actually open 52-29376 (JP, U) Actually open 63-109066 (JP, U) Actually open 57-54760 (JP, U) Actually open 52-139972 (JP, U) Japanese Utility Model Showa 56-120920 (JP, U) Japanese Utility Model Showa 57-135352 (JP, U) Japanese Utility Model Showa 13-11712 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 57/00-57/04

Claims (2)

(57) [Claims] 1. A transmission having at least a pair of gears meshing with each other inside a case, wherein a resonance type silencer is provided at a corner above the meshing position of the gears inside the case, An oil sump is provided below the position, the resonance type silencer adjusts the center frequency of the resonance to the meshing frequency of the gear, and silences two side walls forming a corner portion inside the case. A transmission characterized in that the muffler is used as a side wall of a device, and another wall surface of the silencer is formed on a side sandwiched between two side walls of the corner portion to form a triangular cross section. 2. A transmission having at least a pair of gears meshing with each other inside a case, wherein a resonance type silencer is provided at a corner portion above a meshing position of the gears inside the case, An oil reservoir is provided below the position, the resonance type silencer adjusts the center frequency of the resonance to the meshing frequency of the gear, and the inner wall of the case and the wall constituting the muffler. A transmission characterized by being fixed with an elastic member interposed therebetween.