JP2001027306A - Bevel gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make each tooth hardly collide at the time of assembling and to form a tooth bearing section at only a portion with high machining precision by forming a cut section reaching the vicinity of the pitch line of the tooth toward the tooth bottom side of the outer peripheral end of a tooth body section from the tip side at least at a portion near the outer peripheral side of the tooth body section. SOLUTION: A cut section C is formed to reach the vicinity of the pitch line P of each tooth 4 toward the tooth bottom side of the outer peripheral end of a tooth body section 3 from the tip side at least at a portion near the outer peripheral side of the tooth body section 3. The cut section C is inclined by an angle δ (e.g. 5 degree) against the tip side face of the tooth 4, accordingly the tooth 4 hardly collides at the time of assembling, and a nick is hardly formed on the tooth 4. Since the portion near the outer peripheral end of the tooth body section 3 where machining precision is hardly secured is cut for each tooth 4, a tooth bearing section can be formed only at a portion with high machining precision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bevel gear used for transmitting a rotational driving force between two shafts arranged at an angle to each other.

[0002]

2. Description of the Related Art As shown in a perspective view of FIG. 6, a bevel gear 31 has a tooth body 32 when viewed from the opposite side.
Are formed in such a manner that a plurality of teeth 33 are formed at a certain interval in a ring shape, and these teeth 33 are formed so that the respective tooth traces extend from the outer peripheral side to the inner peripheral side of the tooth body portion 32. The two shafts, which are arranged at an inclination angle to each other, that is, provided at the ends of the rotating shaft on the driving side and the rotating shaft (not shown) on the driven side, respectively, mesh the teeth 32 of each other. Thus, the rotational driving force is transmitted between these two shafts. Then, the teeth 33 are aligned with the central axis O of the tooth body portion 32.
Is formed in a spiral shape having a torsion angle with respect to.

[0003]

Generally, as a gear, noise generated when the driving side bevel gear and the driven side bevel gear are engaged with each other and rotated are reduced, and the quietness is improved. Things are desired. However, when the conventional bevel gear 31 is assembled such that the bevel gears 31 are engaged with each other, the teeth 33 come into contact with each other.
Dents, that is, scratches. When the bevel gears 31 are engaged with each other and rotated, noise is generated due to the contact between the teeth 33 of the bevel gears 31, that is, the dents formed on the tooth contact portions.
When a high load is applied to these bevel gears 31,
Since the teeth 33 are slightly elastically deformed by the load, the tooth contact portion spreads to the outer peripheral end side of the tooth 33, and the bevel gears 31 are moved in a direction in which the bevel gears 31 are separated from each other by this load, and the tooth contact portion moves to the tooth tip side. I do. In this case, it is difficult to ensure processing accuracy on the outer peripheral end side of the teeth 33, so that noise tends to be generated when the teeth 33 come into contact with each other.

Here, as a method of reducing this noise,
There is a method of increasing the twist angle of the teeth 33. This is because, when the bevel gears 31 are engaged with each other and rotated, a plurality of teeth 33 can be engaged at the same time, and the contact area between the teeth 33 of the bevel gears 31 is increased to guide the teeth 33. Is carried out, and thereby the portion of the bevel gears 31 meshed with each other moves to the next tooth 33.
This is to reduce blurring and reduce noise generated when the teeth 33 come into contact with each other. However, even when this method is used, if the helix angle is too large, when forming the teeth 33, the jig for forming the teeth 33 will interfere with the adjacent teeth 33. There was a problem that it became difficult.

The present invention has been made in view of the above circumstances, and has reduced noise generated when a driving-side bevel gear and a driven-side bevel gear mesh with each other and rotate them, thereby improving quietness. It is intended to provide a bevel gear. It is another object of the present invention to provide a bevel gear in which teeth are easily formed.

[0006]

As means for achieving the above object, a bevel gear having the following configuration is employed. That is, when the tooth portion is viewed from the opposite side, the tooth portion is formed with a plurality of teeth at a certain interval in an annular shape, and each tooth has a respective tooth streak on the outer peripheral side of the tooth portion. A bevel gear formed so as to extend toward the inner peripheral side from the outer peripheral end of the tooth body portion from the tooth tip side at least in a portion near the outer peripheral side of the tooth body portion. The bevel gear is characterized in that a cut portion is formed so as to reach the vicinity of the tooth pitch line toward the bottom of the tooth.

In the bevel gear configured as described above,
When the bevel gears are assembled, the bevel gears are likely to interfere with each other, and a cut portion is formed on the tip side near the outer peripheral end of the tooth body part of the tooth, so the teeth are less likely to collide during assembly and dents on the teeth It is difficult to stick. Further, in the teeth, the vicinity of the outer peripheral end of the tooth body portion where it is difficult to ensure the processing accuracy is cut from the tip side to the vicinity of the pitch line, that is, to the theoretical contact portion of each tooth when the bevel gears are meshed. Therefore, the tooth contact portion can be made only a portion with high processing accuracy. Further, since the cut portion is formed in the vicinity of the outer peripheral end of the tooth body portion where the jig for forming the teeth is likely to interfere, the jig hardly interferes with the adjacent teeth when forming the teeth.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bevel gear according to the present invention will be described below with reference to FIGS. here,
FIG. 1 is a perspective view showing the configuration and structure of the bevel gear 1 according to the embodiment. Thus, the basic configuration of the bevel gear 1 is the same as that of the bevel gear 31 shown in FIG. That is, the bevel gear 1 is provided with a tooth portion 3 formed in a substantially circular dish shape at one end of the rotating shaft 2, and the tooth portion 3 is viewed from the side facing the tooth portion 3. A plurality of teeth 4 are formed at regular intervals in the part 3, and the teeth 4 are formed such that the respective tooth traces extend from the outer peripheral side to the inner peripheral side of the tooth body part 3. Things.

FIG. 2 shows a sectional side view of the bevel gear 1. Here, in the bevel gear 1, the teeth 4 are provided with a torsion angle φ (described later). Actually, the teeth 4 cannot be shown on the same cross section as a whole, but in FIG. In order to show the cross-sectional shape along the tooth streak, the entire tooth 4 is drawn as being on the same plane. As shown in FIG. 2, each tooth 4 has a pitch line of the tooth 4 at least in a portion near the outer peripheral side of the tooth body portion 3 from the tip end side toward the bottom of the outer peripheral end of the tooth body portion 3. The cut portion C is formed so as to reach the vicinity of P. The cut portion C has an angle δ with respect to the normal L to the upper surface of the tooth tip, that is, the normal to the surface on the tip side of the tooth 4, which is approximately 4 in the present embodiment.
It is provided at an angle of 5 degrees. Here, the pitch line P is a theoretical contact portion between the teeth when the bevel gears mesh with each other. The pitch line P does not always coincide with the tooth contact portion where the teeth 4 actually contact each other.

Further, the torsion angle φ of the tooth 4 shown in FIG.
For the purpose of improving the quietness of the bevel gear 1, the angle is set in the range of 32 to 40 degrees, preferably 35 degrees or more. The pressure angle α of the tooth 4 shown in FIG. 4, that is, the angle between the radius line r of the tooth body portion 3 and the tangent of the tooth-side surface of the tooth 4 is secured by securing the thickness of the tooth 4. For the purpose of improving the strength, it is preferable to set the range from 16 degrees to 20 degrees.

FIG. 5 shows the tooth portions 3 of the two bevel gears 1 mutually.
FIG. 3 shows a side cross-sectional view in a state in which. Here, these bevel gears 1 have an angle θ at which their axes cross each other,
The gears are engaged so as to be in the range of degrees to 160 degrees, preferably 157 degrees. Here, in FIG. 5, FIG.
Similarly to the above, in order to show the cross-sectional shape along the tooth trace of the tooth 4,
The teeth 4 are depicted as being on the same plane.

In the bevel gear 1 configured as described above, when the bevel gears 1 are assembled, the bevel gears 1 are likely to interfere with each other. Is formed, the teeth 4 are less likely to collide with each other during assembly, and dents are less likely to be formed on the teeth 4. Further, in the teeth 4, the vicinity of the outer peripheral end of the tooth body portion 3 where it is difficult to ensure the processing accuracy is cut from the tooth tip side to the vicinity of the pitch line P, so that the tooth contact portion is limited to a portion with high processing accuracy. be able to. Further, since the tooth tip side of the outer peripheral end of the tooth body portion 3 is cut, a jig (not shown) for forming the tooth 4 at the time of forming the tooth 4 is less likely to interfere with the tooth 4.

As a result, dents are less likely to be formed on the teeth 4, so that when these bevel gears 1 on the driving side and the driven side are engaged with each other and rotated, the generation of noise due to the dents is reduced. be able to. And the tooth contact part of the tooth 4 can be made only the part with high processing accuracy, thereby the tooth 4
Noise generated at the time of contact can be reduced. Also,
Since the jig forming the teeth 4 is less likely to interfere with the adjacent teeth 4 when the teeth 4 are formed, the processing of the teeth 4 becomes easy even when the twist angle φ is large.

In the above embodiment, the cut portion C formed in the tooth 4 is formed in a plane shape inclined with respect to the normal L to the upper surface of the tooth tip of the tooth 4. However, the cut portion C may have a curved surface shape. Further, the cut portion C may be formed so as to extend beyond the pitch line P to the vicinity of the tooth bottom side. In the above embodiment, the bevel gear 1 is a bevel gear formed integrally with the rotating shaft 2. However, the present invention is not limited to this, and a plate formed separately from the rotating shaft 2. It may be shaped as a bevel gear.

[0015]

According to the bevel gear of the present invention, the cut portion is formed on the tooth tip side near the outer peripheral end of the tooth body portion which is likely to interfere with the assembling of the bevel gears. When the bevel gear on the driving side and the bevel gear on the driven side are rotated while meshing with each other, it is possible to reduce the generation of noise due to dents. In addition, the outer peripheral end of the tooth body portion where it is difficult to ensure processing accuracy is cut, and the tooth contact portion can be made only a portion with high processing accuracy, thereby eliminating tooth runout and reducing noise generated at the time of tooth contact. Can be reduced. In addition, since the jig for forming the teeth is less likely to interfere with the adjacent teeth when forming the teeth, the processing of the teeth is facilitated even when the torsion angle of the teeth is large, and the torsion angle of the teeth is increased to increase the umbrella. The quietness of the gear can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a shape of a bevel gear according to an embodiment of the present invention.

FIG. 2 is a front sectional view showing a shape of a bevel gear according to the embodiment of the present invention.

FIG. 3 is an axially orthogonal plan view of the bevel gear according to the embodiment of the present invention as viewed from a tooth body side.

FIG. 4 is an axially orthogonal cross-sectional view of a tooth body of the bevel gear according to the embodiment of the present invention.

FIG. 5 is a front sectional view showing a state in which the bevel gear on the driving side and the bevel gear on the driven side of the bevel gear according to the embodiment of the present invention are engaged with each other.

FIG. 6 is a perspective view showing the shape of a conventional bevel gear.

[Explanation of symbols]

 1 bevel gear 3 tooth body 4 tooth P pitch line C cut part

Continued on the front page (72) Inventor Keiichi Osawa 1230 Kamijiya, Okegawa-shi, Saitama Mitsubishi Material Co., Ltd.Okegawa Manufacturing Co., Ltd. F term in the factory (reference) 3J030 AA08 BA02 BB09 BD02 BD06

Claims (1)

[Claims] When viewed from the opposite side of the tooth portion, the tooth portion is formed with a plurality of teeth annularly at regular intervals, and each tooth has a corresponding tooth trace. A bevel gear formed so as to extend from the outer peripheral side toward the inner peripheral side of the tooth body, wherein each tooth has at least a part near the outer peripheral side of the tooth body part, and the tooth body part from the tooth tip side. Toward the tooth bottom side of the outer peripheral edge of
A bevel gear characterized in that a cut portion is formed so as to reach the vicinity of a tooth pitch line.