JP2000220726A - Noise reduction device of gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To theoretically reduce noise of a gear disposed on a motive power- transmission route. SOLUTION: An annular member 21 is mounted to a side portion of a gear 2. A mounting method is constituted such that the annular member 21 is tightened and fixed to a plurality of circumferential portions 21a,..., 21a by bolts 22, 22 and portions 21b,..., 21b between the respective fixed portions 21a,..., 21a are not contacted with a gear 2 and constitutes a vibration system by floating. When the gear 2 and the annular member 21 are integrally rotated, a compliance is varied as a whole by the fact that a vibration characteristic of the annular member 21 is added in addition to an inherent vibration characteristic of the gear 2. As a result, a displacement quantity in a tooth-abutting direction C becomes larger at a crossing point with a compliance of the other gear 1 engaged therewith and a gear noise is theoretically reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the field of technology for reducing noise of gears on a power transmission path.

[0002]

2. Description of the Related Art For example, in an automobile equipped with an automatic transmission, an output gear of a transmission gear mechanism, an input gear of a differential gear, or a gear between these gears is provided on a power transmission path between an engine and driving wheels. And a number of gears such as reduction gears for increasing and transmitting torque from the automatic transmission side to the drive wheel side. When power is transmitted, the impact generated by the tooth contact between the gears meshing with each other or the noise generated by the natural vibration of the gears is transmitted to the passenger compartment and is unpleasant.

As a prior art for reducing this, as disclosed in Japanese Utility Model Laid-Open Publication No. Hei 6-16759 or Japanese Utility Model Laid-Open Publication No. Hei 7-12653, it is known to attach an annular member to the side of the gear body. I have.

[0004]

However, these methods are intended to reduce the rotational vibration of the gear body by utilizing the rotational inertia of the annular member, and are based on the detailed theory of the gear noise generation mechanism. Since the member is not attached, the noise problem cannot be drastically solved.

[0005] The inventors of the present invention have made and developed a device capable of effectively reducing gear noise based on a new technical idea which has not existed in the past. That is what led to it.

[0006]

That is, the present inventors first paid attention to the fact that the gear noise is correlated with the amount of displacement (deflection) in the contact direction of each gear meshing with each other.

For example, the first gear and the second gear are now in mesh, and the displacement (compliance Ф = frequency response function of displacement) of each gear with respect to frequency (rotational speed) is represented by a Bode line along with its phase. Suppose that it was as shown in FIG. Note that the tooth contact direction is shown in FIG.
, The normal direction C at the contact point between the teeth of the first gear 1 on the driving side that rotates in the direction of arrow A and the teeth of the second gear 2 on the driven side that rotates in the direction of arrow B.

At this time, the teeth of the second gear 2 are
The first gear 1 bends (displaces) rightward in the drawing along the tooth contact direction C due to the pressing force of the teeth, and the teeth of the first gear 1 move along the tooth contact direction C by the reaction force of the teeth of the second gear 2 Deflected (displaced) in the upper left direction. FIG. 12 shows the first gear 1
Of the second gear 2 reaches a peak at a frequency H3 as shown by a dashed line.

The amount of displacement of the first gear 1 is equal to the frequency H1.
The frequency tends to increase until the frequency H1 and then decreases. Similarly, the displacement amount of the second gear 2 tends to increase up to the frequency H3, and turns to decrease after passing the frequency H3. Therefore, the phase of the displacement amount of each of the gears 1 and 2 is reversed at the peak frequencies H1 and H3, respectively.

Then, at another frequency H2 between these frequencies H1 and H3, an intersection X where the compliances # 1 and # 2 of the first and second gears 1 and 2 cross each other is formed. At the intersection X, the displacement amounts of the first and second gears 1 and 2 are the same and the phases are opposite. Therefore, the two gears 1, 2
The dynamic coupling stiffness between the members becomes extremely high (dynamically hard), and the exciting force generated at the tooth contact is not absorbed, and is transmitted to the main body of each of the gears 1 and 2 as it is. As a result, at the frequency H2 at the intersection X, the entire gears 1 and 2 resonate, and large gear noise is generated.

The sound N generated by the engagement between the first gear 1 and the second gear 2 is represented by the following formula: compliance Ф in the tooth contact direction C of the first gear 1.
1 and the reciprocal of the sum of three values of the compliance Ф2 in the tooth contact direction C of the second gear 2 and the meshing compliance Фt determined by the meshing state of the teeth between the two gears 1 and 2.

[0012]

(Equation 1) Here, since the compliance Ф is a value having an amplitude (amount of displacement) and a phase, a complex calculation is actually performed. However, the meshing compliance Δt is a value of only the real part since the phase is always zero.

That is, the amplitude M and the phase P are represented by the following equations using the value R of the real part and the value I of the imaginary part, respectively.

[0014]

(Equation 2)

[0015]

(Equation 3) On the other hand, the compliance Ф1, Ф2 of each gear 1, 2 is
Using the values R1 and R2 of each real part and the values I1 and I2 of each imaginary part, they are expressed as follows.

[0016]

(Equation 4)

[0017]

(Equation 5) Therefore, the above equation (1) is further modified as follows using the value Rt of the real part of the meshing compliance Δt.

[0018]

(Equation 6) In order to facilitate the calculation, a complex conjugate number may be multiplied and modified as follows.

[0019]

(Equation 7) FIG. 13 is a Coquadratic diagram showing the state of FIG. 12 with a real part R and an imaginary part I. As shown, at the intersection frequency H2, the absolute value a of the real part R1 of the compliance Ф1 of the first gear 1 and the absolute value b of the real part R2 of the compliance Ф2 of the second gear 2 are the same and have the same sign. Is reversed, the sum becomes a value very close to zero, so that the dynamic rigidity becomes very large and the gear noise N becomes extremely large. However, since the meshing compliance Δt is not zero and the value of the imaginary part I at the intersection frequency H2 remains as shown by the symbol c, the gear noise N does not become infinite.

As described above, the gear noise increases as the displacement of the gears in the tooth contact direction at the intersection of compliance becomes smaller, in other words, as the deflection becomes less, and the noise becomes larger as the displacement becomes larger. It turns out that it becomes smaller as it deflects. Therefore, the present inventors next increase the amount of displacement in the tooth contact direction of each gear at the intersection, that is, in such a way that the compliances intersect each other where the amount of displacement in the tooth contact direction of each gear is large. It was noted that noise of the gears could be theoretically reduced by eliminating the intersections where the amount of displacement in the gear contact direction of each gear is small.

There are only two possible approaches. First, as illustrated on the low frequency side in FIG. 14, at least the intersection X1 where the displacement is small is eliminated, and instead the intersection X1 ′ where the displacement is large can be set as a new resonance point. This is to add the compliance of another vibration system (same as # 2 ') to the compliance of one gear (# 2 in the illustrated example). Second, as illustrated on the high frequency side in FIG. 14, at least the intersection X2 where the displacement is small is eliminated, and instead the intersection X2 'where the displacement is large can be set as a new resonance point. The peak of compliance of one gear (also Ф2) is dispersed to broaden the tail, and the compliance with a high displacement level as a whole (also Ф2)
2 ″).

Based on the above findings, the present inventors have found that by attaching another member to the gear body so as to have its own frequency, the above two effects and the harmonic break effect can be simultaneously achieved. I found it to be realizable.

That is, the present invention relates to a gear noise reduction device provided on a predetermined power transmission path, wherein an annular member is connected to a side portion of the gear body at a plurality of circumferential portions. And a portion other than the connection portion is provided so as not to contact the gear body.

[0024] The space between the adjacent coupling portions floats from the gear main body and forms one vibration system. Therefore, by rotating integrally with the gear body, each vibration system vibrates greatly at its natural frequency, and the compliance of another vibration system as a whole of the annular member in which these are synthesized is the original compliance of the gear itself. Is added to As a result, the first method is realized, and a new resonance point (for example, X1 ') intersecting at a large displacement can be obtained instead of a resonance point intersecting at a small displacement.

At this time, if the position of the coupling portion can be changed in the circumferential direction, the natural frequency of each vibration system can be changed, and the new resonance point can be changed according to the compliance of the gear or the compliance of the mating gear. This is preferable because it can be generated at the target frequency.

By the way, the rotating body generally rotates, so that a two-node mode (2ND mode) with two nodes and a three-node mode with three nodes are obtained at a specific rotation speed (frequency).
Each mode shape such as a knot mode (3ND mode) is taken. For example, in FIG. 14, the peak on the low frequency side of the compliance Ф2 of the second gear 2 is in the two-node mode, the peak on the high frequency side is in the three-node mode,
And so on. There, when the annular member according to the present invention is attached, according to the number of the binding sites, each mode shape,
For example, a low-frequency side (soft) mode shape and a high-frequency side (hard) mode shape are separated into a plurality of parts with the peak frequency before the annular member attached.

For example, when the number of connecting portions is three, the connecting portion on the gear side to which the annular member is connected has high rigidity, and the non-contact portion on the gear side where the other annular members are floating has low rigidity. Become. Therefore, the entire gear rotates as if a new three-joint mode was forcibly added, and the original three-joint mode shape of the original gear was separated into two or more mode shapes. , The original three-node mode peak is dispersed into peaks of a plurality of different frequencies. As a result, the base of compliance expands and the overall displacement level changes to a higher one, and the second method is realized, and a new point of intersection at a large displacement is replaced with a resonance point at a small displacement. A resonance point (for example, X2 ') can be obtained.

Therefore, the number of binding sites may be determined according to the number of nodes in the vibration mode of the target peak to be separated. In addition to the above, for example, when the number of binding sites is two, the compliance Δ on the low frequency side in FIG.
2, two-node mode peaks or four-node mode peaks are dispersed.

Further, since the annular member is joined to the gear body to form a portion having a high rigidity and a portion having a low rigidity, the way of contact of the teeth with the portion of high rigidity and the manner of contact of the teeth with the portion of low rigidity are described. And a behavior as if it were a random pitch gear. Therefore, the excitation force is not constant (not stable), a harmonic break effect is obtained, and a frequency region where gear noise is reduced as a whole is created.

Hereinafter, the present invention will be described in more detail through embodiments of the present invention.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present embodiment, the present invention relates to a primary gear 1, which is an output gear of an automatic transmission 100 shown in FIG.
In order to reduce noise generated by engagement with the secondary gear 2 on the secondary shaft 12 for transmitting the output of the differential gear 200 to the differential device 200, that is, the second gear,
This is applied to the secondary gear 2 side.

The automatic transmission 100 includes an engine output shaft 10
Converter 2 to which the engine rotation is input via
0, and first and second planetary gear mechanisms 30 and 40 as a transmission mechanism into which the rotation of the converter 20 is input via the primary shaft 11 which is the axis of the primary gear 1. Forward clutch 51 between sun gear 31 of first gear mechanism 30, reverse clutch 52 between shaft 11 and sun gear 41 of second gear mechanism 40, shaft 11 and second gear mechanism 40
3-4 clutch 53 between the pinion carrier 42 and
A 2-4 brake 54 for fixing the sun gear 41 of the second gear mechanism 40, a low reverse brake 55 between the ring gear 33 of the first gear mechanism 30 and the pinion carrier 42 of the second gear mechanism 40 and the transmission case 101, Fourth forward speed and one reverse speed are realized by the selective operation of the plurality of friction elements of the one-way clutch 56.

The primary gear 1 is rotatably provided on the primary shaft 11 by being connected to the pinion carrier 32 of the first gear mechanism 30 and the ring gear 43 of the second gear mechanism 40, and meshes with the secondary gear 2. Also,
Reduction gear 3 on secondary shaft 12 and differential 20
The output rotation of the primary gear 1 is input to the differential case 201 of the differential device 200, and the left and right axles 13 and 14 are driven via the differential device 200.

FIG. 2 shows a specific structure of the automatic transmission 100. As shown in FIG. 3, FIG. 3 and FIG.
An annular groove 2a is formed in the main body side of the secondary gear 2, and an annular member 21 is attached to the secondary gear 2 so as to be housed in the annular groove 2a. In that case,
The annular member 21 is fixed by crimping with two bolts 22, 22 at three connecting portions 21a. In the portions 21b... 21b between the adjacent coupling portions 21a, the annular member 21 does not contact the secondary gear 2 and is in a state of floating from the gear 21.

Therefore, when the annular member 21 rotates integrally with the secondary gear 2, the annular member 21 is rotated.
Of the secondary gear 2 is added to the original compliance of the secondary gear 2. In that case, by changing the circumferential fastening position of the two bolts 22, 22,
The length of each of the non-contact portions 21b... 21b can be changed, whereby the added new resonance point is generated at a target frequency according to the compliance of the secondary gear 2 or the compliance of the primary gear 1. It becomes possible.

Further, since the annular member 21 is fixed at three points, the three-joint mode shape of the secondary gear 2 is separated into two or more mode shapes, and the peak of the displacement amount in the three-joint mode is obtained. Are distributed to peaks of a plurality of different frequencies. On the other hand, for example, if this annular member 21 is fixed at two points,
Is divided into two or more mode shapes, and the peaks of the displacement amount in the two- or four-node modes are dispersed into peaks of a plurality of different frequencies from each other. .

In any case, the compliance of the secondary gear 2 and the compliance of the primary gear 1 intersect at a position where the amount of displacement in the tooth contact direction C is large, so that gear noise is effectively reduced. Will be.

FIG. 5 is a graph showing the effect of attaching the annular member 21. The compliance of the primary gear 1 is indicated by a solid line, the compliance of the secondary gear 2 when the annular member 21 is not attached is indicated by a broken line, and the compliance of the secondary gear 2 when the annular member 21 is attached is indicated by a chain line. The peak (A) is a two-node mode peak of the primary gear 1, the peak (A) is an original two-node mode peak of the secondary gear 2, and the peak (C) is a three-node mode peak and a peak ( D) Secondary gear 2
Is the original three-bar mode peak.

Excessive gear noises (s), (s), and (c) generated at the compliance intersections (f), (g), and (h) at positions where the displacement is relatively small when the annular member 21 is not attached. (S) has been eliminated, and instead, the compliance intersections (T), (H), and (T) at positions where the displacement amount is relatively large, respectively, have been produced, so that the gear noise is effectively (N), It can be seen that it is reduced as shown in (d) and (nu).

Here, the reduction of gear noise from (S) to (D) is due to the result of adding the compliance peak (C) of the annular member 21 as another vibration system. The reduction from (v) to (v) is due to the result that the three-node mode peak (d) of the secondary gear 2 is dispersed into two peaks (h) and (h). Further, the reduction of the gear noise from (S) to (N) is a result of an increase in the overall level of compliance of the secondary gear 2 due to these effects.

FIG. 6 shows an example of a vibration mode shape (3-joint mode shape) of the annular member 21 at the peak (C), and FIG. 7 shows an original 3-joint mode shape of the secondary gear 2 at the peak (D). An example of FIG.
FIG. 9 shows an example of a three-node mode shape of the secondary gear 2 at the separated peak (H) on the lower frequency side.
FIG. 2 conceptually illustrates an example of the three-node mode shape of the secondary gear 2 at the separated peak (f) on the high frequency side.

FIG. 10 is a graph showing a harmonic break effect obtained by attaching the annular member 21. As shown in FIG. The gear noise when the annular member 21 is not attached is shown by a solid line, and the gear noise when the annular member 21 is attached is shown by a broken line. As shown, the gear noise is significantly reduced in the frequency domain (m). In this frequency region (M), the intersection between the compliance of the primary gear 1 and the compliance of the secondary gear 2 has not moved to a place where the displacement amount is so large, and therefore, the gear noise in this wide range (M) is large. The reduction is due to the third effect of the harmonic break effect provided by the attachment of the annular member 21.

As described above, by attaching the annular member at a plurality of connecting portions, a portion having high rigidity and a portion having low rigidity are generated on the gear side, whereby the separation of the mode shape or the dispersion of the compliance peak is reduced. As a result, since a harmonic break occurs, a gear 2 'having a perforated structure as shown in FIG. 11, for example, may be employed. The gear 2 'has high rigidity at five connecting portions 2a'... 2a 'connecting the central portion and the peripheral portion, and has low rigidity at five connecting portions 2b'... 2b '. Therefore, the entire gear 2 'rotates in a manner that a new five-bar mode is forcibly added, and a noise reduction effect due to peak dispersion or a harmonic break effect can be obtained. Needless to say, the number of perforations may be other numbers such as four or six.

The annular member 21 may be provided on the primary gear 1 side, or may be provided on both gears 1 and 2.

In this case, the annular member 21 is mounted so as to be accommodated in the annular groove 2a.
Does not protrude, does not hinder rotation of the gear, and does not impair the layout of the gear.

Further, a gear 2 ′ having a perforated structure may be employed as the primary gear 1,
And may be employed for both gears 1 and 2.

The ring member 2 is attached to one of the gears 1 or 2.
1 may be attached, and the other gear 2 or 1 may be a perforated gear.

[0048]

As described above, according to the present invention, the gear noise can be effectively reduced based on the theory of the mechanism of gear noise generation and based on a new technical idea which has not existed before. INDUSTRIAL APPLICABILITY The present invention is widely and preferably applicable to the automobile industry and the machine industry using gears for transmitting power, in general.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing a mechanical configuration of an automatic transmission for a vehicle to which the present invention is applied.

FIG. 2 is a sectional view showing a peripheral structure of a transmission gear mechanism of the automatic transmission.

FIG. 3 is a sectional view showing a structure around a gear to which an annular member according to the present invention is attached.

FIG. 4 is a front view of the gear.

FIG. 5 is a graph showing a noise reduction effect of the gear.

FIG. 6 is a schematic view showing an example of a vibration mode shape of the annular member.

FIG. 7 is a schematic diagram showing an example of the original three-bar mode shape of the gear.

FIG. 8 is a schematic diagram showing an example of a three-node mode shape on the low frequency side of the same gear separated.

FIG. 9 is a schematic diagram showing an example of a three-node mode shape on the high frequency side.

FIG. 10 is a graph showing a harmonic break effect as a noise reduction effect of the gear.

FIG. 11 is a front view showing a gear having another structure that produces a harmonic break effect and the like.

FIG. 12 is an explanatory diagram of the present invention.

FIG. 13 is an explanatory diagram of the present invention.

FIG. 14 is an explanatory diagram of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary gear (1st gear) 2 Secondary gear (2nd gear) 2a Annular groove (recess) 21 Annular member 21a Connection part 21b Non-contact part 30, 40 Planetary gear mechanism (transmission mechanism) 100 Automatic transmission 200 Difference Motion device

Continued on the front page (72) Inventor: Mamoru Ishii, 3-1 Fuchi-machi, Shinchu, Aki-gun, Hiroshima Mazda Co., Ltd. ) Inventor Yuzo Okawa 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Shohei Kumano 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Pref. Mazda Co., Ltd. (72) Inventor Yasunori Kanda Hiroshima Machida Co., Ltd., 3-1, Fuchu-cho, Shinchi, Aki-gun, Japan (72) Inventor Koichi Hatamura 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. F-term (reference) 3J030 AA08 BA01 CA10

Claims (7)

[Claims] 1. A device for reducing noise of a gear disposed on a predetermined power transmission path, wherein an annular member is connected to a side portion of a gear body at a plurality of circumferential portions. A noise reduction device for a gear, wherein the noise reduction device is provided so as not to come into contact with the gear body in a portion other than the portion. 2. The gear noise reduction device according to claim 1, wherein the annular member is housed in a recess formed in a side portion of the gear body. 3. The power transmission path is a power transmission path between an engine of an automobile and a driving wheel. On the path, a first gear, which is an output gear of a speed change mechanism, and a first gear are provided. A second gear for meshing and transmitting the output of the transmission mechanism to the differential is provided, and the annular member is provided on at least one of the first and second gears. The gear noise reduction device according to claim 1. 4. The annular member is provided so as to add another vibration system to increase the amount of displacement of each gear in the tooth contact direction at the intersection of the compliance with the rotation speed of each of the first and second gears. The gear noise reduction device according to claim 3, wherein: 5. The annular member is provided so as to disperse the compliance peak so as to increase the amount of displacement in the tooth contact direction of each gear at the intersection of the compliance with the rotation speed of each of the first and second gears. The gear noise reduction device according to claim 3, wherein: 6. The gear noise reduction device according to claim 4, wherein the position of the coupling portion is changeable in a circumferential direction. 7. The gear noise reduction device according to claim 5, wherein the number of coupling portions is determined according to the number of nodes of the vibration mode of the gear when the compliance reaches a peak.