JP2001271912A - Gear and gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the torsional vibration of a power transmitting system and noise. SOLUTION: A cog 4 is divided into two parts in a gear width direction by a slit 5. Two pairs meshing area 8a on an addendum surface of one gear piece 4b of the cog 4 divided into two parts is removed. Therefore, the difference in apparent rigidity between a state where the two pairs of cogs 4 are meshed and a state only one pair of the cogs 4 are meshed is eliminated, so that rapid changes in the flexibly deforming amount of the cog 4 at transmitting power can be suppressed. Consequently, the torsional vibration of the power transmitting system can be reduced, so that noise due to the torsional vibration can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear and a gear device widely used in a power transmission mechanism of a copying machine, a printer, a facsimile, a camera, a VTR, an electric washing machine, parts for automobiles and the like.

[0002]

2. Description of the Related Art As shown in FIG. 17, a power transmission mechanism such as a copying machine or an automobile part has many gear units K1 constituted by combining a spur gear pair 20, which is one of parallel shaft gear pairs. Is used. Here, in the spur gear pair 20 of the gear device K1, a general spur gear pair 20 having an involute tooth profile and a contact ratio ε formed in a range of 1.0 <ε <2.0 is shown in FIGS. As shown in FIG. 13, two sets of teeth 41A-41B, 42A-42B (43A, 43B).
Are meshed (FIGS. 9 to 10, 13), and one set of teeth 41A to 41B is meshed (FIGS. 11 to 12). The apparent stiffness of the teeth changes rapidly depending on the case (FIG. 18).
reference). As a result, the amount of bending deformation of the teeth 21 of the spur gear pair 20 greatly differs between the case where the two sets of teeth 21 mesh with the case where the one set of teeth 21 mesh with each other. It causes torsional vibrations due to sudden fluctuations in the volume. The torsional vibration of the power transmission system causes a rotation transmission error in an image forming unit, a transfer unit, and the like of a color copying machine or a color laser printer, thereby causing a color shift problem. Further, the power transmission mechanism using the spur gear pair 20 generates noise due to torsional vibration. Here, the apparent stiffness is the combined stiffness of the teeth in the engaged state at the same time. Therefore, the apparent stiffness of the teeth when two sets of teeth are in mesh with each other is approximately twice as large as the state where one set of teeth is meshed.

A pair of spur gears having a meshing ratio ε of 2.0 <ε may have two sets of teeth meshing with each other, or three sets of teeth meshing with each other. In this case, the apparent stiffness of the teeth is greatly different from the case where the gears mesh with each other, and the noise caused by the torsional vibration and the torsional vibration is reduced in the same manner as in the case of the spur gear pair having the meshing ratio ε of 1.0 <ε <2.0. Will happen.

Therefore, conventionally, the teeth 21 of the spur gear pair 20
Various techniques have been developed to reduce the torsional vibration of the power transmission system and to reduce the noise caused by the torsional vibration by suppressing the rapid fluctuation of the amount of flexural deformation of the power transmission system.

For example, as shown in FIGS. 19 and 20, a non-contact surface 22 of each tooth 21 of a pair of spur gears 20 and a part 23 of a two-pair meshing region are notched (first conventional example). 21, or as shown in FIG. 21, a hole 24 penetrating from one side surface to the other side surface of the tooth 21 is formed (second conventional example) to reduce the stiffness of the two-pair meshing region on the tip side of the tooth 21. By reducing the difference between the amount of bending deformation of the teeth 21 during two-pair meshing and the amount of bending deformation of the teeth 21 during two-pair meshing, a technique for reducing torsional vibration has already been devised. (Japanese Unexamined Patent Publication No. 8-31275)
No. 5).

As shown in FIGS. 22 and 23, a reinforcing plate 25 is fixed to the side surface of a tooth 21 of a driving gear (spur gear 20A) of a spur gear pair 20, and a driven gear (spur gear 20) is fixed.
B) A reinforcing plate 26 is fixed to the side surface of the tooth 21 (third conventional example), the stiffness of the pair of meshing regions of the tooth 21 is increased, the amount of bending deformation of the tooth 21 at the time of pairing and the tooth at the time of two pairing. A technique for reducing the difference in the amount of flexural deformation of 21 to reduce torsional vibration has already been devised (see Japanese Patent Application Laid-Open No. H8-312755).

Further, in the pair of spur gears, the tooth shape is modified by an amount corresponding to the amount of deformation of the teeth and the manufacturing error so that the meshing ratio is 2.0, and two sets of teeth are always meshed with each other. A technique for achieving reduction (fourth conventional technique) has already been devised (see Japanese Patent Application Laid-Open No. 5-340463).

[0008] Further, as shown in FIG.
A groove 27 extending from the tip of the tooth 21 to the rotation center side and crossing the tooth 21 in the tooth width direction is formed to reduce the stiffness on the tip side of the tooth 21 so that the engagement of the tooth 21 and the engagement of the tooth 21 end. (Fifth prior art) has already been devised (above-mentioned JP-A-9-4697 and JP-A-63-13564).
No. 7).

[0009]

However, the first conventional example has a problem that the spur gear pair 20 can only transmit rotation in one direction and cannot transmit rotation in both forward and reverse directions. Have.

Further, the second conventional example has a problem that it is extremely difficult to balance the amount of flexural deformation and the strength of the tooth tip because the tooth tip of the tooth 21 receiving the force has a small thickness. are doing.

In the third conventional example, since the reinforcing plates 25 and 26 are separately fixed to the side surfaces of the teeth 21 of the spur gears 20A and 20B, the number of manufacturing steps of the spur gears 20A and 20B is increased. In addition, the spur gears 20A and 20B have a disadvantage that the unit price of the spur gears 20 increases, and due to the variation in the mounting accuracy of the spur gear pair 20, the side surfaces of the teeth of one spur gear 20 become reinforcing plates of the other spur gear. , Which may cause new noise.

In the fourth conventional example, the contact ratio ε is 2.
If the gear specifications of 0 or more cannot be selected, it is not possible to implement it. In addition, it is necessary to perform tooth profile modification with high accuracy, and the tooth profile modification is not easy, resulting in an increase in the production unit price of the spur gear. have.

In the fifth conventional example, since the groove 27 is formed in the tooth tip, there is a problem that it cannot be applied to a spur gear in which the tooth tip surface cannot be sufficiently secured.

Accordingly, an object of the present invention is to reduce the torsional vibration of the power transmission system and the noise without causing the problems caused by such a conventional example.

[0015]

That is, in the gear according to the present invention, the teeth are divided into a plurality of teeth in the width direction by slits, and at least one of the plurality of teeth excluding at least one of the plurality of teeth. It is characterized in that the tip side of the tooth piece has been removed.

Further, in the gear according to the present invention, the teeth are divided into a plurality of teeth in the face width direction by the slits, and at least one of the plurality of teeth excluding at least one of the teeth has a distal end. It is characterized in that both tooth surfaces are cut out so as to be concave.

Further, the gear device according to the present invention is a gear device in which at least one pair of gears mesh with each other, and at least one of the gears of the pair of gears meshes with a plurality of teeth in the width direction by slits. It is characterized in that the tip of the other tooth excluding at least one of the plurality of teeth is removed.

The gear device according to the present invention is a gear device in which at least one pair of gears mesh with each other, and the teeth of at least one gear of the pair of gears meshing with each other are formed into a plurality of tooth pieces in a tooth width direction by a slit. It is characterized in that it is divided and both tooth surfaces on the tip side of the other teeth except for at least one of the plurality of teeth are cut out so as to be concave.

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

[First Embodiment] FIGS. 1 to 3 show a spur gear 1 as a parallel shaft gear according to a first embodiment of the present invention. As shown in these figures, a spur gear 1 according to the present embodiment has a shaft hole 3 fitted to a shaft 2 at the center.
Are formed, and the engagement ratio ε is 1.0 <ε <2.
A large number of involute teeth 4 formed to be 0 are formed.

The teeth 4 of the spur gear 1 are bisected in the tooth width direction by the slits 5, so that the tooth pieces 4a and 4b bisected by the slits 5 are each independently bent and deformed. Here, the slit 5 is formed at a substantially central portion in the tooth width direction of the tooth 4, and is formed at a depth reaching the tooth bottom surface 7 from the tooth tip surface 6. The width W of the slit 5 is set to a width that can be processed. However, it is preferable to set the width W as small as possible in order to reduce the tooth width as much as possible. Further, when the spur gears 1 and 1 are engaged with each other as in a spur gear pair 11 (see FIG. 6) described later, the width W of the slit 5 depends on the mounting error of the spur gears 1 and the like. It is preferable to design so that the tooth piece 4a and the other tooth piece 4b do not interfere with each other.

One of the tooth pieces 4b of the bisected tooth 4 is removed so that the two pairs of engagement areas 8a on the tip side are cut off. As a result, as shown in FIG. 5 to FIG. 6, the spur gear pair 11 in which the
In the two pairs of engagement areas 8a and 8b, the bisected tooth 4
Only the other teeth 4a, 4a are engaged with each other, and in the pair of meshing regions 10, all the teeth 4a-4a, 4b-
4b mesh with each other, the apparent stiffness of the teeth 4 becomes equal between the paired meshing state and the two paired meshing state (FIG. 7).
Reference), the amount of bending deformation of the teeth 4 in the paired meshing state and the amount of bending deformation of the teeth 4 in the two paired meshing state do not suddenly change. Note that the stiffness of the teeth 4 is changed to an upwardly convex chevron shape as shown in FIG. 7 due to the tooth profile, and thus slightly fluctuates as the meshing progresses. Therefore, in the spur gear 1 of the present embodiment, the amount of bending deformation slightly changes with the progress of meshing, but since there is no sharp change in the stiffness of the teeth 4 unlike the conventional example, torsional vibration Less likely to occur.

That is, as shown in FIG. 9, when the meshing of the teeth 41A of the driving gear is started, the spur gear pair 11 has the tooth root surface of the driving gear tooth 41A and the tooth tip surface of the driven gear tooth 41B. Are in contact at a point 13 on the action line 12, and the tooth flank face of the drive gear tooth 42A and the root face of the driven gear tooth 42B are in contact at a point 14 on the action line 12, The two sets of teeth 41A-41B and 42A-42B are in mesh. As the engagement between the driving gear and the driven gear further progresses, as shown in FIGS. 9 and 10, the contact point 13 moves so as to approach the pitch circles 15A and 15B, and the contact point 14 moves.
Move away from the pitch circles 15A and 15B. In addition, in the state of FIGS.
Numeral 3 is located in the two-tooth meshing area 8b of the tooth root surface of the drive gear tooth 41A, while being located in the two-tooth meshing area 8a of the tooth tip surface of the driven gear tooth 41B (see FIG. 3). .
The contact point 14 is located in the two-tooth meshing area 8a of the tooth apical surface of the drive gear tooth 42A, while the driven gear tooth 42A
B is located in the paired meshing area 8b of the tooth root surface (see FIG. 3).

As the meshing between the drive gear and the driven gear further progresses, as shown in FIG. 11, the tip of the tooth end of the drive gear tooth 42A separates from the action line 12 and the drive gear tooth 4A
2A does not come into contact with the driven gear tooth 42B, and the tooth root surface near the pitch circle 15A of the drive gear tooth 41A and the tooth tip surface near the pitch circle 15B of the driven gear tooth 41B contact only at the point 13. I do. Then, when the meshing between the driving gear and the driven gear further proceeds, the contact point 13 in FIG. 11 moves to the position of the contact point 13 in FIG. 11 to 12 show a state in which only one set of the driving gear tooth 41A and the driven gear tooth 41B mesh with each other, and the contact point 13 is located in the paired meshing region 10 of the driving gear and the driven gear. (See FIG. 3).

As the meshing between the driving gear and the driven gear further progresses, as shown in FIG. 13, the contact points 13 between the teeth 41A of the driving gear and the teeth 41B of the driven gear become pitch circles 15A and 15A.
B, the end face of the drive gear tooth 41A and the root face of the driven gear tooth 41B come into contact with each other, and the root face of the next tooth 43A of the drive gear and the next tooth 43B of the driven gear. Meshes with the end face of the tooth (contact point 16), and the teeth 41 of the drive gear
A, 43A and two sets of driven gear teeth 41B, 43B are brought into a state of meshing. 9 to 13, in the present embodiment, the positions corresponding to the tooth apex surfaces of the tooth pieces 4 b in which the two pairs of meshing regions on the tip side are cut off are indicated by a two-dot chain line in the present embodiment. Is virtually indicated by.

Here, the pair of spur gears 11 formed by meshing the spur gears 1 and 1 according to the present embodiment is formed by cutting out the two meshing regions 8a of the tooth flank of one of the tooth pieces 4b. In the states shown in FIGS. 3 and 5), FIGS. 9 to 10 and FIG. 13, one tooth piece 4b, 4b is not in contact with each other, and the other tooth piece 4a, 4a is in a two-pair meshing state. For this reason, compared with a general spur gear designed under the same conditions such as the tooth width as the spur gear 1 of the present embodiment, the meshing tooth width of the two pairs of meshing teeth is reduced, and accordingly, The apparent stiffness of the teeth 4 is reduced. The spur gear pair 11 of the present embodiment, which is formed by meshing the spur gears 1, 1, has a pair of teeth 4 a, 4 a of the set of teeth 4, 4 in the state of FIGS.
b are in a paired engagement state. As a result, as described above, the apparent stiffness of the teeth 4 does not differ between the state in which one set of teeth 4 meshes and the state in which two sets of teeth 4 mesh (see FIG. 7). Therefore, the pair of spur gears 11 formed by engaging the pair of spur gears 1 and 1 of the present embodiment is less likely to generate torsional vibration as described above.

As described above, in the present embodiment, the spur gear 1
Of the tooth 4 is cut in the width direction of the tooth by the slit 5, and is cut out so as to remove the two pairs of meshing regions 8a on the end face of one tooth piece 4b. Since the apparent stiffness of the teeth 4 can be made equal between the pair of meshing states, the amount of bending deformation of the teeth 4 does not suddenly change, and the occurrence of torsional vibration can be prevented. Generation of noise due to vibration can be prevented. Therefore, as shown in FIG. 6, when the gear device K of the present embodiment, which is formed by engaging at least one pair of the spur gears 1, is used for a power transmission mechanism such as a color copier or a color laser printer.
It is possible to perform quiet and accurate rotation transmission, and it is possible to effectively prevent problems such as color misregistration.

Further, in the present embodiment, the spur gear pair 11 can be rotated in both forward and reverse directions, and the spur gear 1 does not have a thinner tooth tip. It is not a configuration for fixing the reinforcing plate. Furthermore, in this embodiment, since the two pairs of meshing regions 8a of the tooth flank surface of one tooth piece 4b are simply removed, the tooth profile is modified by an amount corresponding to the deformation amount of the tooth 4 and the manufacturing error. Compared with the conventional example, the spur gear 1 can be easily formed. In addition, the present embodiment can be applied to a case where the tooth tip surface 6 cannot be sufficiently secured.
Therefore, according to the present embodiment, the disadvantages of the first to fifth related arts can be solved.

The spur gear pair 11 according to the present embodiment is
The mode in which the notched tooth pieces 4b, 4b are engaged with each other has been described, but the present invention is not limited to this, and the notched tooth piece 4b of the driving gear and the other tooth piece 4 not cut of the driven gear are not limited to this.
a, and the other tooth piece 4 without the notch of the drive gear
a and one of the notched tooth pieces 4b of the driven gear may be engaged with each other.

Further, the present embodiment exemplifies a mode in which the width of the teeth 4 is increased so that the stiffness of the teeth 4 in the paired meshing state is equal to the stiffness of the teeth 4 in the two meshing state. (See FIG. 7 (a)), two pairs of meshing teeth 4
The width of the teeth 4 may be adjusted so that the stiffness is equal to the stiffness of the teeth 4 in the paired meshing state (see FIG. 7B). Note that the former is a mode in which two pairs of meshing regions 8a are cut out and added to the spur gear 4b to a spur gear having a predetermined tooth width, and the latter is a mode in which the tooth 4 of the spur gear having a predetermined tooth width is used as it is. Is divided into two pieces 4a and 4b.

In this embodiment, as shown in FIG.
Although the aspect in which the entire two-pair meshing region 8a of the tooth tip surface of one tooth piece 4b is cut out is exemplified, the invention is not limited to this. By adjusting the notch amount of the two-pair meshing region 8a (see FIG. ) And (b)), the amount of bending deformation of the teeth 4 may be adjusted.

[Second Embodiment] FIG. 4 is a partially enlarged perspective view of teeth 4 of a spur gear 1 according to a second embodiment of the present invention. As shown in FIG. 4, in the spur gear 1 of the present embodiment, the teeth 4 are divided into three in the face width direction by the slits 5 and 5 (teeth pieces 4 c to 4 e), and the tooth pieces 4 c and 4 e on both sides are the same. It is formed in a shape. Of these, the spur gear 1 shown in FIG. 4 (a) has two pairs of meshing regions 8a of the tooth flank surfaces of the tooth pieces 4c and 4e on both sides cut away. On the other hand, FIG.
In the spur gear 1 shown in (b), only two pairs of meshing regions 8a on the end face of the tooth piece 4d at the center are cut out. The spur gear pair 11 formed by meshing a pair of the spur gears 1 having such a configuration (the spur gears 1 shown in FIG. 4A or the spur gears 1 shown in FIG. 4B) acts on the teeth 4. The force always acts equally to the left and right with respect to the center position in the tooth width direction, and a force that inclines the center line of the shaft hole 3 with respect to the axis of the shaft 2 fitted into the shaft hole 3. Without any action, smoother rotation transmission is enabled (see FIG. 6).

[0032] The spur gear 1 of the present embodiment having the above-described structure is used.
And a gear device having at least one pair of the spur gear 1
As in the first embodiment, the stiffness of the teeth 4 in the paired meshing state and the apparent stiffness of the teeth 4 in the two-pair meshing state are made the same, torsional vibration is effectively suppressed, and noise caused by the torsional vibration is reduced. Can be prevented from occurring.

[Third Embodiment] FIGS. 14 and 15 show
9 shows a spur gear 1 according to a third embodiment of the present invention. That is, in the spur gear 1 according to the present embodiment, as shown in these figures, the teeth 4 are divided into two in the width direction of the teeth (tooth pieces 4a and 4b) by the slits 5, and one of them is provided. In the tooth piece 4b, the two pairs of meshing regions 8a, 8a of the tooth tip surfaces on both sides are partially removed (notched) so as to leave the tooth tip surface 6.

One tooth 4 of the tooth 4 thus divided into two
In b, the two pairs of meshing regions 8a on the tip side are more concave than the original tooth surface (the tooth surface before notching). As a result, the spur gear pair formed by engaging the spur gear 1 of the present embodiment with a pair is
In the two pairs of engagement areas 8a and 8b, the bisected tooth 4
Only the other teeth 4a, 4a are engaged with each other, and in the pair of meshing regions 10, all the teeth 4a-4a, 4b-
4b mesh with each other, the apparent stiffness of the teeth 4 becomes equal between the paired meshing state and the two paired meshing state (FIG. 7).
Reference), the amount of bending deformation of the teeth 4 in the paired meshing state and the amount of bending deformation of the teeth 4 in the two paired meshing state do not suddenly change. This is true when the spur gear 1 rotates in both the forward and reverse directions, similarly to the spur gear 1 according to each of the above-described embodiments.

As described above, the spur gear 1 according to the present embodiment has the apparent stiffness of the teeth 4 in the paired meshing state and the apparent stiffness of the teeth 4 in the paired meshing state, as in the above-described embodiments. And torsional vibrations can be effectively suppressed, and generation of noise due to torsional vibrations can be prevented.

[Other Application Examples] In each of the above embodiments, the case where the contact ratio ε is 1.0 <ε <2.0 has been described as an example. However, the present invention is not limited to this. It is also applicable when ε is 2.0 <ε. That is, when the meshing ratio ε is 2.0 <ε, a state in which two pairs of teeth 4 mesh with each other and a state in which three pairs of teeth 4 mesh with each other occur. Of the cases where the same tooth is divided into a plurality of tooth pieces, By cutting out the three pairs of meshing regions of the tooth flank surfaces of the other teeth other than at least one tooth like the two pairs of meshing regions of each of the above embodiments, it is more smooth than those of the above embodiments. And quiet rotation transmission can be enabled.

Further, in each of the above embodiments, the mode in which the teeth 4 are divided into two or three by the slits 5 in the width direction of the teeth is shown, but the present invention is not limited to this.
It is also possible to divide the teeth into two or more and to cut out the two pairs of meshing areas on the end face of the other teeth except for at least one of the plurality of teeth.

In each of the above embodiments, the tooth width of each tooth piece 4a, 4b, 4c, 4d, 4e is changed as appropriate.
The amount of bending deformation of each tooth 4 may be adjusted.

Further, in the first embodiment, the mode in which the slit 5 is formed to the depth reaching the tooth bottom surface 7 from the tooth tip surface 6 has been exemplified. However, the present invention is not limited to this. It may be changed appropriately to adjust the amount of bending deformation of the tooth pieces 4a and 4b.

FIG. 8 (a) or FIG. 8 (b)
As shown in FIG. 1, a general spur gear 17 is used for one of the driving gear and the driven gear, and the general spur gear 17 is used as the spur gear 1 of the first embodiment or the second embodiment. The form of the spur gear 1 may be meshed.

The present invention is not limited to the above embodiments, but can be applied to a gear device having a configuration in which an external gear meshes with an internal gear.

The present invention is widely applied to resin gears formed by injection molding, metal gears formed by cutting, metal gears formed by die casting, and the like.

[0043]

As is apparent from the above description, in the gear of the present invention, the teeth are divided into a plurality of teeth in the width direction by slits, and at least one of the plurality of teeth is removed. By removing the tip side of the other tooth pieces, abrupt fluctuations in the amount of bending deformation of the teeth during power transmission can be suppressed, so that the disadvantages of the conventional example can be solved, It is possible to reduce noise caused by torsional vibration. Therefore, the gear device in which at least one pair of the gears of the present invention meshes can reduce torsional vibration of the power transmission system and noise caused by the torsional vibration, thereby enabling quiet and accurate rotation transmission.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a spur gear according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the spur gear shown in FIG.

FIG. 3 is an enlarged view showing a part of the spur gear according to the first embodiment of the present invention. FIG. 3A is an enlarged perspective view showing a part of the spur gear, and FIG. 3B is a view seen from the direction A in FIG. 3A.

FIG. 4 is an enlarged perspective view showing a part of a spur gear according to a second embodiment of the present invention. FIG. 4A is a perspective view showing a first example, and FIG. 4B is a perspective view showing a second example.

FIG. 5 is a perspective view showing a spur gear pair in which a pair of spur gears according to the first embodiment of the present invention are meshed.

6 is a longitudinal sectional view of the spur gear pair shown in FIG.

FIG. 7 is a diagram showing a change in stiffness of the teeth of the pair of spur gears according to the first embodiment. FIG. 7A is a diagram illustrating a change in stiffness of the teeth when the tooth width is increased, and FIG. 7B is a diagram illustrating a change in the stiffness of the teeth when the tooth width is not increased.

FIG. 8 is a longitudinal sectional view showing a spur gear pair according to another embodiment of the present invention. FIG. 8A is a diagram illustrating a first example of another embodiment, and FIG. 8B is a diagram illustrating a second example of another embodiment.

FIG. 9 is a diagram showing a meshing state of a first stage of the spur gear pair.

FIG. 10 is a diagram showing a meshing state of the second stage of the spur gear pair.

FIG. 11 is a diagram showing a third stage of meshing of the pair of spur gears.

FIG. 12 is a diagram showing a meshing state of a fourth stage of the spur gear pair.

FIG. 13 is a diagram illustrating a meshing state of the fifth stage of the spur gear pair.

FIG. 14 is an enlarged perspective view showing a part of a spur gear according to a third embodiment of the present invention.

FIG. 15 is an enlarged front view showing a part of a spur gear according to a third embodiment of the present invention.

FIG. 16 is a diagram showing an application example of the spur gear according to the first embodiment of the present invention. FIG. 16A is a side cross-sectional view of a spur gear showing a first application example, and FIG. 16B is a side cross-sectional view of a spur gear showing a second application example.

FIG. 17 is an external perspective view of a conventional spur gear pair.

FIG. 18 is a diagram illustrating a change in stiffness of a tooth of a conventional spur gear pair.

FIG. 19 is an enlarged view of a meshing portion of a spur gear pair showing the first related art.

FIG. 20 is an enlarged perspective view of the teeth of the pair of spur gears of FIG. 19;

FIG. 21 is an enlarged view of a meshing portion of a spur gear pair showing a second conventional technique.

FIG. 22 is an enlarged view of a meshing portion of a spur gear pair showing a third related art.

23 is a longitudinal sectional view of the pair of spur gears shown in FIG. 22.

FIG. 24 is an enlarged view of a meshing portion of a spur gear pair showing a fifth related art.

[Explanation of symbols]

1 ... Spur gear (parallel shaft gear), 4, 41A, 41B, 4
2A, 42B, 43A, 43B ... teeth, 4a to 4e ...
Tooth piece, 5 ... Slit, K ... Gear device

Claims (4)

[Claims] A tooth is divided into a plurality of tooth pieces in a width direction by a slit, and at least one of the plurality of tooth pieces is divided into a plurality of tooth pieces.
A gear characterized in that the tip side of another tooth excluding the tooth is removed. 2. A tooth is divided into a plurality of tooth pieces in a tooth width direction by a slit, and at least one of the plurality of tooth pieces is divided.
A gear characterized in that both tooth surfaces on the tip side of other tooth pieces except the tooth piece are cut out so as to be concave. 3. A gear device in which at least one pair of gears mesh with each other, the teeth of at least one of the pair of meshing gears are divided into a plurality of teeth in a tooth width direction by a slit. 3. The gear device according to claim 1, wherein a tip end of another tooth excluding at least one tooth is removed. 4. A gear device in which at least one pair of gears mesh with each other, the teeth of at least one of the pair of gears meshing with each other are divided into a plurality of teeth in a tooth width direction by a slit. A gear device characterized in that both tooth surfaces on the tip side of the other tooth pieces except for at least one tooth piece are cut out so as to be concave.