JPH08285048A - Three-dimensional tooth surface modification structure in helical/double-helical gear - Google Patents

Abstract

PURPOSE: To provide three-dimensional tooth surface modification structure in a helical gear or a double-helical gear that can relax shock at the mesh start time so as to be able to realize low vibration and low noise. CONSTITUTION: In a helical/double-helical gear of large face width having the reference tooth surface with an involute curve as tooth profile so as to transmit high load, bias modification is applied to tooth profile shape so that the tooth profile shape is made different by a tooth trace direction S position on the curved surface in line with the involute curved surface from a mesh start part 2 on the tooth surface and that the modified quantity T of the mesh start part in a tooth surface normal direction becomes the quantity of flexure at least at the meshed time of the gear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention according to this application relates to a three-dimensional tooth surface modification structure in which a reference tooth surface is modified in a helical gear or a helical gear having an involute tooth profile, and particularly, to transmit a high load and The present invention relates to a three-dimensional tooth surface modification structure in a helical gear or helical gear having a long tooth width that requires low vibration and noise.

[0002]

2. Description of the Related Art Helical gears or helical gears (hereinafter referred to as "helix / yamaba") that are used to transmit the power of a driving gear to a driven gear in all industrial fields. Gears are manufactured with geometrically correct involute tooth surface shapes and correct pitches, and are capable of transmitting correct uniform rotation when operated at low speed with no load.

However, helical actual / double-helical gear, since the metal itself which is the material of the gear is an elastic body, as schematic diagram showing the meshing state of the gear of FIG. 5, the drive gear G ₁ And the driven gear G ₂ mesh with each other and a load acts, the tooth pair 1
Since 1 transmits the power while bending from the design meshing state of the solid line like the imaginary line, the drive gear G ₁ side advances at the base of the tooth pair 11 as shown by the imaginary line and the driven gear G ₂
The side will be delayed. On the other hand, at this time, the tooth pair 11a next to the meshed tooth pair 11 does not bend because the load is not yet applied, but it shifts from the solid line to the imaginary line.

Therefore, the pitch p ₁ on the drive gear G ₁ side is smaller than the regular pitch p ₀ between the tooth pair 11 of the imaginary line on which the load is applied and the tooth pair 11a of the next imaginary line. , the pitch p ₂ of the driven gear G ₂ side becomes greater than the pitch p ₀ of the normal, next tooth pair 11a is when the meshes of the driven gear G ₂ addendum corner 11b of the drive gear G ₁ dedendum Contact is initiated by a shocking engagement that bites into the.

Further, when the drive gear G ₁ has a negative pitch error or a positive pressure angle error, this shocking meshing is further promoted, which causes vibration and noise to increase.

By the way, in the spur gear, in consideration of the above-mentioned impact at the beginning of meshing, the tip relief at the tip of the tooth,
Alternatively, tooth profile modification such as root / relief at the root may be performed. However, this tooth profile modification can be carried out uniformly if there is a contact line along the entire length of the tooth width in the tooth trace direction, as in the case of a spur gear.
As shown in the perspective view of the contact line in the helical gear, the meshing advancing direction V travels diagonally on the tooth surface and the contact line L on the tooth surface crosses the tooth trace direction S diagonally / yama For bevel gears, when end relief at the tooth end, uniform tooth profile modification in the tooth trace direction S, or a combination of these is applied, the amount of the tooth profile and the central portion of the tooth trace unrelated to the start of meshing are measured. The result is that the tooth surface effective for load transmission is unnecessarily reduced. Moreover,
The impact mitigation effect similar to the tooth profile modification in the spur gear cannot be expected for the impact at the beginning of meshing.

Further, conventionally, due to manufacturing restrictions, end relief at the tooth end and uniform tooth profile modification in the tooth trace direction,
Alternatively, it has been unavoidable to take measures for impact mitigation at the beginning of meshing by two-dimensional tooth surface modification by a combination thereof.

On the other hand, in recent years, due to the development of production technology, three-dimensional tooth surface modification in which the tooth profile modification shape is different depending on the tooth trace direction position is becoming possible, and the invention of a low-vibration and low-noise gear by the three-dimensional tooth surface design technology There is an invention described in JP-A-63-180766. The present invention is a bias correction in which a pressure angle correction amount in a tooth width direction gradually changes so that a tooth contact portion of a pair of gears meshing with each other extends long along a meshing advancing direction on a reference tooth surface forming an involute tooth profile. It is a three-dimensional tooth surface modification that has been performed.

However, according to this three-dimensional tooth surface modification method, the tooth profile modification amount (pressure angle modification) is adjusted according to the tooth trace direction position so that the tooth contact portions of a pair of gears meshing with each other extend long along the meshing advancing direction. The amount) is gradually changed to reduce the transmission error that causes vibration and noise.
No consideration was given to the impact mitigation at the beginning of meshing.
Therefore, the purpose and problem are different from the invention of this application,
Moreover, it is impossible to solve the vibration and noise due to the impact at the beginning of meshing in the helical / helical gear having a long tooth width under a high load condition, which is the object of the invention of this application.

In view of the above problems, the invention of this application is
It is an object of the present invention to provide a three-dimensional tooth surface modification structure for a helical gear or a helical gear that can reduce impact and vibration and noise at the beginning of meshing.

[0011]

In order to achieve the above object, a three-dimensional tooth surface modification structure in a helical / compact gear according to claim 1 has a reference tooth surface having an involute curve as a tooth profile. In a helical / helical gear with a long tooth width that transmits high load, the tooth profile is a curved surface that is continuous from the meshing start part on the tooth surface to the involute curved surface. It is characterized by having been modified.

The three-dimensional tooth surface modification structure of the helical / compact gear according to claim 2 is bias modified in the three-dimensional tooth surface modification structure of the helical / compact gear of claim 1 described above. It is characterized in that the modification amount of the meshing start portion in the direction of the tooth surface normal is formed by at least the bending amount at the gear meshing.

A three-dimensional tooth surface modification structure in a helical / compact gear according to a third aspect is the bias in the three-dimensional tooth surface modification structure in the helical / compact gear in claim 1 or claim 2. When the modification amount in the normal direction of the modified tooth surface is expressed as the relative modification amount between a pair of driving and driven gears that mesh with each other on the working surface, the contour line is almost parallel to the inclination of the contact line. It is characterized in that it is applied with a tooth surface modification shape to be

The three-dimensional tooth surface modification structure in the helical / helical gear according to claim 4 is the helical / corrugated structure according to any one of claims 1 to 3 above.
One of the three-dimensional tooth surface modification structures of a helical gear is characterized in that a bias modification is applied to one pitch in the tooth depth direction.

[0015]

According to the three-dimensional tooth surface modification structure in the helical / helical gear according to the first to fourth aspects, the tooth profile is a curved surface continuous from the meshing start portion on the tooth surface to the involute curved surface, and the tooth profile is in the tooth trace direction. Due to the shape of the tooth profile with different bias modification depending on the position, there is a large impact at the beginning of meshing in a helical gear or helical gear with a long tooth width that has a reference tooth surface with an involute curve as the tooth profile and transmits a high load. It is possible to transmit power by meshing without generating.

Particularly, according to the three-dimensional tooth surface modification structure in the helical / compact gear according to the second aspect, the meshing is performed in the tooth surface normal direction in which the bias modification is performed at least by the deflection amount at the time of gear meshing. Since the amount of modification at the beginning is formed, the impact at the beginning of meshing can be further alleviated.

Particularly, according to the three-dimensional tooth surface modification structure in the helical / compact gear according to claim 3, modification in the relative tooth surface normal direction between the pair of driving and driven gears meshing with each other is performed. When the amount was expressed on the working surface, the contour line was biased so that it was almost parallel to the inclination of the contact line, so as the meshing progressed, the contact line moved substantially parallel to the contour line and moved in the perpendicular direction. Can reduce the impact.

Particularly, according to the three-dimensional tooth surface modification structure of the helical / helical gear according to the fourth aspect, since the bias modification is performed for one pitch in the tooth-engaging direction, the leading teeth are properly meshed. When the next state is reached, the next tooth is located at the meshing start portion where the bias is adjusted, and smooth meshing always starts.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention according to this application will be described below with reference to the drawings illustrating a helical gear as an example. 1 is a perspective view showing a tooth of a helical gear of the invention according to this application, FIG. 2 is an explanatory view showing a working surface obtained by expanding a reference tooth surface of the tooth of FIG. 1, and FIG. FIG. 4 is a side view of the tooth showing a range for performing the tooth surface modification, and FIG. 4 is a sectional view taken along line AA of FIG. 3.

As shown in the drawing, the meshing start portion 2 on the tooth flank located at one lower corner of the tooth 1 forming a helical gear having a reference tooth flank having an involute curve as a tooth profile, is engaged with this meshing start portion 2. In the curved surface that is continuous from the starting portion 2 to the involute curved surface, the tooth profile is biased differently depending on the position S in the tooth trace direction.

The modification amount T in the tooth surface normal direction at the meshing start portion 2 of this bias modification is, in this embodiment,
As shown in FIG. 4, it is formed with a modification amount T that is substantially equal to the amount of flexure at the time of gear meshing, and the bias modification is performed on a curved surface that continues from the meshing start portion 2 to the involute curved surface.

The amount of modification T at the meshing start portion 2 is
If it is formed with at least the amount of bending when meshing gears,
It is possible to prevent the impact caused by the pitch change caused by the bending at the time of gear engagement. Even if the correction amount T is equal to or more than the bending amount, the meshing start position is shifted to the regular tooth flank side, but smooth meshing is possible.

Further, as shown in FIG. 2, the tooth surface modification shape (bias relief) of this bias modification is the amount of modification in the relative tooth surface normal direction between a pair of driving and driven gears meshing with each other. When represented on the action surface f as, the contour line m is formed to be substantially parallel to the inclination α of the contact line. Thus, the contour line m is defined by the inclination α of the contact line L (FIG. 3).
If it is formed so as to be substantially parallel to, the meshing can be smoothly advanced along with the movement of the contact line L (FIG. 3) due to the meshing of the teeth.

In this embodiment, this bias modification is carried out for one pitch q in the toothbrushing direction, as shown in FIG. By performing the bias modification for q for one pitch in this way, when the previous tooth is in the normal meshing state, the next tooth is located at the meshing start portion where the bias is modified, so that the smoothness is always smooth. A helical gear can be constructed in which the meshing starts. In this embodiment, the bias correction of the meshing start portion 2 is applied to one pitch q in the tooth profile direction R, but the same applies to one pitch in the tooth trace direction S.

According to the helical gear of the present embodiment constructed as described above, the bias gear applied to the meshing start portion 2 causes the drive gear G ₁ as shown in FIG.
Since the impact at the beginning of meshing caused by elastic deformation and pitch error caused by the load acting on the teeth when the gear and the driven gear G ₂ mesh with each other can be effectively mitigated, the vibration at the meshing start portion 2 It is possible to realize low vibration and low noise of helical gears by reducing noise and noise.

Therefore, in a helical gear having a reference tooth surface having an involute curve as a tooth profile and having a long tooth width for transmitting a high load, low vibration and low noise can be realized, and meshing at the beginning of meshing under a high load condition can be achieved. The impact is effectively mitigated, and gear vibration and noise can be reduced.

The helical / helical gear having a long tooth width for transmitting a high load in the invention according to this application is, for example, a helical / helical gear having an overlapping mesh ratio of at least 2 or more. .

Further, in the above embodiment, the helical gear has been described as an example, but the same effect can be obtained in the helical gear, and the invention according to this application has a contact line with respect to the tooth surface. The same effect can be obtained in the inclined gear.

Further, in the above embodiment, the contact line moves substantially in parallel with the contour line of the correction amount of the normal direction of the tooth flank on the working surface in accordance with the progress of the meshing state of the gear and moves in the right angle direction to form the normal meshing. The impact at the beginning of meshing can be alleviated even if there is some deviation.

[0030]

Since the invention according to this application is configured as described above, it has the following effects.

According to the three-dimensional tooth surface modification structure for the helical / compact gears according to the first to fourth aspects, the meshing is performed by the bias modification applied to the curved surface connected to the involute curved surface from the meshing start portion on the tooth surface. Since it is possible to transmit power by meshing without generating a large impact at the beginning, at the beginning of meshing in a long tooth width helical / helical gear having a reference tooth surface with an involute curve as a tooth profile It becomes possible to construct a helical / helical gear that effectively absorbs shock and reduces vibration and noise of the gear.

Particularly, according to the three-dimensional tooth surface modification structure of the helical / compact gear according to claim 2, since the bias modification is performed at least by the flexure amount at the time of gear meshing, the impact at the start of meshing Hasha /
It is possible to configure a helical gear.

Particularly, according to the three-dimensional tooth surface modification structure in the helical / compact gear according to the third aspect, the contact line is in the normal direction of the tooth surface on the working surface as the meshing state of the gear shifts. Since it is possible to move to a normal mesh by moving in a direction substantially parallel to the contour line of the correction amount and at a right angle, it is possible to always maintain continuous line contact at the beginning of meshing instead of point contact. / It becomes possible to configure a helical gear.

Particularly, according to the three-dimensional tooth surface modification structure of the helical / helical gear according to the fourth aspect, the meshing in which the next tooth is bias-modified when the preceding tooth is in the normal meshing state Since the meshing is performed from the beginning, it is possible to configure a helical / helical gear in which smooth meshing always starts.

[Brief description of drawings]

FIG. 1 is a perspective view showing teeth of a helical gear of the invention according to this application.

FIG. 2 is an explanatory view showing a working surface in which a reference tooth surface of the tooth of FIG. 1 is developed.

FIG. 3 is a side view of a tooth showing a range to be three-dimensionally modified according to the invention of this application.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a schematic view showing a meshing state of a conventional gear.

FIG. 6 is a perspective view showing contact lines in a helical / helical gear.

[Explanation of symbols]

1 ... Tooth 2 ... Engagement start part T ... Modification amount R ... Tooth profile direction S ... Tooth trace direction L ... Contact line V ... Interlocking advancing direction f ... Working surface m ... Contour line q ... 1 pitch α ... Inclination of contact line p ₀ ... regular pitch p ₁ ... driving gear side pitch p ₂ ... driven gear side pitch

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsugu Yamashita 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries Ltd. Kobe factory (72) Mitsuru Obana Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo 3-1-1 Kawasaki Heavy Industries, Ltd. Kobe factory (72) Inventor Yoshimasa Sakai 3-1-1 1-1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries Ltd. Kobe factory

Claims (4)

[Claims] 1. A helical / helical gear having a tooth flank having an involute curve as a tooth profile and transmitting a high load and having a long tooth width, wherein the tooth profile is formed into a meshing start portion on the tooth surface. A three-dimensional tooth surface modification structure in a helical / compact gear that is characterized in that the tooth shape is different on the curved surface connected to the involute curved surface depending on the tooth trace direction position. 2. The helical spacer according to claim 1, wherein the amount of modification of the meshing start portion in the direction of the tooth surface normal to which the bias has been modified is formed by at least the amount of deflection at the time of gear meshing. Three-dimensional tooth surface modification structure for helical gears. 3. When the amount of modification in the direction of the tooth surface normal to which the bias modification has been applied is expressed as the relative amount of modification between a pair of driving and driven gears meshing with each other on the working surface, the contour lines make contact with each other. The three-dimensional tooth surface modification structure in a helical / helical gear according to claim 1 or 2, wherein the tooth surface modification shape is substantially parallel to the inclination of the line. 4. A three-dimensional tooth surface modification structure for a helical / helical gear according to claim 1, wherein one pitch in the tooth depth direction is bias-modified. .