JPH11303974A - Scissors gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scissors gear capable of reducing chattering sound by eliminating backlash, capable of reducing noise caused by meshing frequencies, and having a simple structure. SOLUTION: In the scissors gear composed of a main gear 3 having a main tooth 33 to be meshed with a tooth space 77 of a mating gear 7, and a sub gear 2 having a sub tooth 23 to be meshed with the tooth space 77 of the mating gear 7, and for pinching the tooth of the mating gear 7 by both gears, an energizing means (a plate spring 5) for relatively approaching both gears in the rotational shaft direction is arranged, an inclined surface inclined toward the sub gear 2 side is formed on the main tooth 33, an inclined surface inclined to the main gear 3 side is formed on the sub tooth 23, and the main tooth 33 and the sub tooth 23 are meshed with the tooth space 77 of the mating gear 7 in a state where the inclined surfaces are partially faced to and overlapped on each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scissor gear capable of substantially eliminating backlash between gears meshing with each other, reducing rattling noise caused by rotation fluctuation, and reducing noise caused by the meshing frequency.

[0002]

2. Description of the Related Art Conventionally, as a power transmission gear, the following scissor gear has been used in order to eliminate backlash between gears and reduce rattling noise caused by rotation fluctuation. As shown in FIGS. 5 to 8, the scissor gear includes a sub gear 92, a main gear 93, a spring 94,
And a spring 95.

The sub gear 92 and the main gear 93 are
As shown in FIG. 5, the sub gear 92 is locked by the spring 95 urged in a direction to approach the main gear 93 side. The sub gear 92 is shown in FIGS.
As shown in (1), there is a sub tooth 923 that meshes with the tooth groove 77 of the mating gear 7. The main gear 93 has main teeth 933 that mesh with the tooth grooves 77 of the mating gear 7. As shown in FIG. 6, the sub gear 92 is arranged in parallel with the main gear 93. Further, the sub teeth 923 of the sub gear 92 correspond to the main teeth 9 of the main gear 93.
No interference with 33.

FIG. 6 shows a cross section taken along line AA in FIG. FIG. 7 is a view taken in the direction of the arrow X in FIG. FIG. 7 shows the timing immediately after FIG.

As shown in FIG. 8, the spring 94 is a C-shaped spring urged in the opening direction.
One end 941 is inserted into the hole 920 of the sub gear 92, and the other end 942 is inserted into the hole 93 of the main gear 93.
0, the sub gear 92 and the main gear 9
3 is provided. The spring 94
A knocking pin for positioning and a dedicated jig (not shown) are used for the arrangement.

As shown in FIG. 6, the urging force of the spring 94 acts on the sub teeth 923 of the sub gear 92 in the forward direction and acts on the main teeth 933 of the main gear 93 in the reverse direction. . The driving side is the mating gear 7 described above. Then, as shown in FIG. 7, the sub teeth 923 and the main teeth 933 sandwich the teeth 73 of the mating gear 7, so that the scissor gear 9 eliminates backlash and reduces rattling noise. The term “scissors gear” may be used to refer to only the sub gear 92 and referred to as a “scissors gear”.

Further, in the power transmission gear, in addition to the backlash and the rattling noise caused by the rotation fluctuation, noise is also generated due to the meshing and contact of the teeth of the normal gear. This noise is generally expressed as a meshing frequency, and it is known that the lower the meshing ratio, the more likely it is to increase. For example, as shown in FIG. 6, in the scissor gear 9, if the width So of the sub-teeth 923 with respect to the width Wo of the mating gear 7 is the meshing ratio Bs,
The lower the meshing ratio Bs, the greater the noise due to the meshing frequency.

[0008]

However, the conventional scissor gear has the following problems. That is, the scissor gear 9 is composed of the sub teeth 923 and the main teeth 93.
3 are arranged in parallel without interfering with each other.
The width So of the sub-teeth 923 and the width of the main teeth 933
Is approximately equal to the width Wo of the mating gear 7. Therefore, the width So of the sub teeth 923 that can mesh with the teeth 77 of the mating gear 7 is limited to the width of the main teeth 9.
33, it is difficult to increase the meshing ratio Bs. Therefore, rattling noise can be reduced, but it is difficult to reduce noise due to the meshing frequency.

In particular, when the scissor gear 9 cannot have a sufficient width in the rotation axis direction, the sub gear 9
Since the width So of the second sub-teeth 923 becomes narrower, the meshing ratio Bs is further reduced, and noise due to the meshing frequency is likely to increase.

In order to reduce the rattling noise even when the torque fluctuates greatly, the urging force of the spring 94 must be increased. In this case, the sub teeth 923 and the main teeth 933 are required. , And the pressing force applied to the teeth 73 of the mating gear 7 becomes excessively large. In particular, an excessive pressing force is applied to a portion where the sub-teeth 923 having a small width So meshes with the teeth 73 of the mating gear 7. , These wear faster and may cause damage to them in a short period of time.

The scissor gear 9 uses the spring 94 to shift the sub-tooth 923 and the main tooth 933 in the rotation direction. However, there is a problem in that the assembly of the spring 94 is troublesome. is there. In order to solve this, a tooth clutch can be formed as shown in Japanese Utility Model Laid-Open No. 4-128568. However,
In this case, since teeth for teeth are required separately from the sub teeth 923 and the main teeth 933, the structure becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a simple structure of a scissor gear capable of eliminating backlash, reducing rattling noise, and reducing noise due to a meshing frequency. It is intended to provide.

[0013]

According to a first aspect of the present invention, there is provided a main gear having a main tooth meshing with a tooth groove of a mating gear, and a main gear disposed on the same rotation shaft as the main gear, and meshing with the tooth groove of the mating gear together with the main gear. A scissor gear having a main gear and a sub-teeth sandwiching the teeth of the mating gear; and a biasing means for relatively bringing the main gear and the sub-gear relatively close to each other in the rotation axis direction. The main teeth of the main gear are formed with inclined surfaces inclined in a direction in which the thickness of the main teeth decreases toward the sub gear, while the sub teeth of the sub gear have An inclined surface inclined in a direction in which the thickness of the tooth becomes thinner is formed, and the main tooth and the sub-tooth form the mating tooth with a part of the inclined surface overlapping each other. In Shizasugiya, characterized in that it is configured to mesh with the tooth spaces.

The most remarkable point in the present invention is that the main teeth of the main gear and the sub teeth of the sub gear are
Each of the above-mentioned inclined surfaces inclined as described above is formed,
The meshing of the mating gears with the mating gears in a state in which a part of the mating gears is superposed.

Next, the operation and effect of the present invention will be described.
In the scissor gear according to the present invention, the urging force of the urging means acts in a direction in which the main gear and the sub gear move closer to each other. For example, when the sub-gear is pressed toward the main gear by the urging force of the urging means, a part of the inclined surface of the sub-tooth protrudes toward the main gear, and the sub-tooth is inclined in the tooth groove of the mating gear. Facial overlap with part of the inclined surface of the main teeth. Then, the urging force of the urging means acting on the sub-gear is dispersed from the rotation axis direction to the rotation direction.

Therefore, when the mating gear is on the driving side, the inclined surface of the sub-tooth presses the tooth of the mating gear in the reverse rotation direction via the main tooth which has been overlapped. Also,
The meshing surface of the sub-tooth presses the adjacent tooth via the tooth space in the normal rotation direction. Therefore, the sub teeth of the sub gear and the main teeth of the main gear eliminate backlash and reduce rattling noise.

According to the scissor gear of the present invention, the inclined surface of the sub-tooth and a part of the inclined surface of the main tooth are arranged so as to face each other. Therefore, the width of the sub-tooth, which can mesh with the tooth groove of the mating gear, can be increased by an amount protruding toward the main gear. Therefore, even when, for example, the scissor gear cannot have a sufficient width in the rotation axis direction, the meshing ratio can be easily increased, and the noise due to the meshing frequency can be reduced.

Further, the width of the sub-tooth meshing with the tooth space of the mating gear is increased by an amount protruding toward the main gear. Therefore, it is possible to prevent the pressing force applied to the sub-tooth, the main tooth, and the tooth of the mating gear from being partially excessive. Therefore, the wear resistance can be improved.

Further, the scissor gear applies a biasing force of the biasing means directly to the sub-tooth and the main tooth, thereby giving a rotational deviation to the sub-tooth and the main tooth.
Therefore, there is no need to arrange a spring or to form a tooth clutch separately from the above-mentioned sub-tooth and main tooth as in the conventional case. Therefore, the scissor gear has a simple structure with a small number of parts.

Next, as in the second aspect of the present invention, the mating gear, the main gear and the sub gear can be constituted by helical gears. In this case, the area in which the sub-tooth of the sub-gear can mesh with the tooth space of the mating gear is larger than that of a scissor gear having the same meshing ratio constituted by a spur gear. Therefore, the width of the scissor gear in the rotation axis direction can be reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment A scissor gear according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 4, the scissor gear of the present embodiment is disposed on the same rotating shaft as the main gear 3 having the main teeth 33 meshing with the tooth grooves 77 of the mating gear 7, and is disposed together with the main gear 3. The main gear 33 and the sub teeth 23 sandwich the teeth 731 of the mating gear 7 with the sub teeth 2 having the sub teeth 23 meshing with the tooth grooves 77 of the mating gear 7 (FIG. 3). Further, a disc spring 5 is provided as an urging means for bringing the main gear 3 and the sub gear 2 relatively closer to each other in the rotation axis direction.

As shown in FIG. 2, the main teeth 33 of the main gear 3 are formed with an inclined surface 334 that is inclined in a direction in which the thickness of the main teeth 33 decreases toward the sub gear 2 side. On the other hand, the sub teeth 23 of the sub gear 2 are formed with inclined surfaces 236 that are inclined in the direction in which the thickness of the sub teeth decreases toward the main gear 3 side.
Further, the main teeth 33 and the sub teeth 23 are configured to mesh with the tooth grooves 77 of the mating gear 7 in a state where the inclined surfaces 334 and 236 are partly overlapped with each other.

The details will be described below. In the scissor gear 1, the mating gear 7, the main gear 3, and the sub gear 2 are all helical gears. The mating gear 7 is a driving gear that is rotated by a driving force from a driving source (not shown), and the main gear 3 is a driven gear that is rotated by the rotation of the mating gear 7.

The main gear 3 is, as shown in FIG.
It has a main tooth 33 that meshes with the tooth groove 77 of the mating gear 7 and a cylindrical boss 35 that protrudes in the rotation axis direction. The tip 351 of the boss 35 is projected in the radial direction by fixing the plate with bolts (not shown). The sub gear 2 is rotatably and slidably engaged with the boss 35, and has the sub teeth 23 meshing with the tooth groove 77 of the mating gear 7.

The disc spring 5 serving as an urging means is disposed between the tip portion 351 of the boss 35 and the outer surface of the sub gear 2, and presses the sub gear 2 toward the main gear 3. It is urged in the direction to be. In addition, as the urging means, a wave washer, a hydraulic cylinder or the like can be used in addition to the disc spring 5.

As shown in FIGS. 1 and 2, the main teeth 33 and the sub teeth 23 have inclined surfaces 334 and 236 in the rotation axis direction of the scissor gear 1.
Of the mating gear 7 in a state in which a part of the
Mesh with. Note that the mating gear 7 has teeth 731, 73
9 are alternately arranged. In addition, the tooth space 77
Are formed between the teeth 731 and 739. FIG. 2 shows a BB cross section in FIG.

Further, as shown in FIG.
3 has a mating surface 331 on the opposite side of the inclined surface 334. The meshing surface 331 is formed in parallel with the tooth trace of the mating gear 7 and meshes with the tooth 731 of the mating gear 7. Further, the inclined surface 334 is formed in a tapered shape different from the tooth trace of the mating gear 7.

Also, as shown in FIG.
Has a mating surface 239 on the opposite side of the inclined surface 236. A part of the inclined surface 236 is formed parallel to the inclined surface 334 of the main tooth 33 and overlaps with a part of the inclined surface 334. The meshing surface 239 is formed in parallel with the tooth trace of the mating gear 7 and meshes with the tooth 739 of the mating gear 7. Further, the width Sn of the sub-teeth 23 is wider than the width So of the conventional sub-teeth 923, and
3 is equal to the width Mo of the conventional main teeth 933.
The width Wn of the counterpart gear 7 is smaller than the width Wo of the conventional counterpart gear 7. FIG. 4 is a sectional view showing a state where the main gear and the sub gear are disassembled.

Next, the operation and effect of this embodiment will be described. In the present embodiment, as shown in FIG. 1, the sub gear 2 is pressed toward the main gear 3 by the urging force of the disc spring 5. In this case, as shown in FIG. 2, a part of the inclined surface 236 of the sub tooth 23 protrudes toward the main gear 3 and a part of the inclined surface 334 of the main tooth 33 in the tooth groove 77 of the mating gear 7. And face-to-face polymerization. Then, the urging force P of the disc spring 5 acting on the sub gear 2 is dispersed from the rotation axis direction to the rotation direction, and becomes the pressing forces Q and R.

Therefore, the inclined surface 236 of the sub-tooth 23
Is driven by the mating gear 7 via the main teeth 33 overlapped with each other.
Is pressed in the reverse rotation direction. The meshing surface 239 of the sub-tooth 23 presses the tooth 739 of the mating gear 7 in the forward rotation direction. FIG. 3 shows C-
The C section is shown. FIG. 3 shows the timing immediately after FIG. At this time, the meshing surface 331 of the main tooth 33 and the meshing surface 231 of the next sub tooth 23 sandwich the tooth 731 of the mating gear 7. Therefore, the sub teeth 23 of the sub gear 2 and the main teeth 33 of the main gear 3 eliminate backlash and reduce rattling noise.

According to the present embodiment, as shown in FIG. 2, the sub teeth 23 and the main teeth 33 are inclined with respect to each other by inclined surfaces 236 and 236.
334 (FIG. 4) are arranged in a face-to-face state.
Therefore, the width Sn of the sub teeth 23 that can mesh with the tooth groove 77 of the mating gear 7 can be increased by the width J protruding toward the main gear 3. Therefore, even when the scissors gear 1 cannot have a sufficient width in the rotation axis direction, the meshing ratio Bs can be easily increased, and noise due to the meshing frequency can be reduced.

The width Mn of the main teeth 33 in the scissor gear 1 is equal to the width Mo of the conventional main teeth 933.
But the same as the sub-tooth 23,
It can be protruded to the side. In this case, if the width Mn of the main teeth 33 with respect to the width Wn of the mating gear 7 is defined as the meshing ratio Bm, the meshing ratio Bm can be increased similarly to the meshing ratio Bs. Therefore, noise due to the meshing frequency can be further reduced. Conversely, the width Wn of the counterpart gear 7 in the scissors gear 1 can be made smaller than the width Wo of the conventional counterpart gear 7.

The width Sn of the sub-teeth 23 meshing with the tooth groove 77 of the mating gear 7 is increased by the width J protruding toward the main gear 3. Therefore, the above-mentioned sub tooth 2
3, the main teeth 33 and the teeth 731 and 739 of the mating gear 7
Can be prevented from becoming excessively large, and concentrating on a particularly narrow portion. Therefore, the wear resistance can be improved.

The scissor gear 1 converts the urging force P of the disc spring 5 into the pressing forces Q and R, and directly acts on the sub teeth 23 and the main teeth 33, thereby causing the sub teeth 23 and the main teeth 33 to move. To the rotational direction. Therefore, there is no need to dispose the spring 94 or to form a tooth clutch separately from the sub teeth 23 and the main teeth 33 as in the related art. Therefore, the scissor gear 1 has a simple structure with a small number of parts.

The counter gear 7, the main gear 3, and the sub gear 2 are all helical gears. Therefore, the same meshing ratio Bs composed of spur gears
The area where the sub teeth 23 of the sub gear 2 can mesh with the tooth groove 77 of the mating gear 7 is larger than that of the scissor gear having the above. Therefore, the width of the scissor gear 1 in the rotation axis direction can be easily reduced.

In this embodiment, the case where the sub gear 2 is pressed toward the main gear 3 is shown. However, the case where the main gear 3 is pressed toward the sub gear 2 or both directions are opposite to each other. The same can be said for the case of being pressed to

When the main gear 3 is a driving gear and the mating gear 7 is a driven gear,
The inclined surface 236 of the sub-tooth 23 presses the tooth 731 of the mating gear 7 in the forward rotation direction via the main tooth 33 overlapped. The meshing surface 239 of the sub-tooth 23 is
The adjacent teeth 739 are pressed in the reverse rotation direction via the tooth grooves 77. In this case, when the structure of the previous example shown in FIGS. 1 to 4 is used, the rotation direction of the gear is reversed.

[0038]

As described above, according to the present invention, it is possible to provide a scissors gear having a simple structure capable of eliminating backlash, reducing rattling noise, and reducing noise due to the meshing frequency. it can.

[Brief description of the drawings]

FIG. 1 is a front view of a scissor gear according to an embodiment.

FIG. 2 is a cross-sectional view showing a state where main teeth and sub teeth mesh with tooth spaces according to the embodiment;

FIG. 3 is a side view showing a state where main teeth and sub-tooth are meshed with tooth spaces according to the embodiment;

FIG. 4 is an exemplary sectional view of a state where a main gear and a sub gear are disassembled according to the embodiment;

FIG. 5 is a front view of a scissor gear according to a conventional example.

FIG. 6 is a cross-sectional view of a conventional example in a state where main teeth and sub teeth mesh with tooth spaces.

FIG. 7 is a side view showing a state in which main teeth and sub-tooth mesh with a tooth space according to a conventional example.

FIG. 8 is an exploded perspective view of a main gear, a sub gear, and a spring according to a conventional example.

[Explanation of symbols]

 1. . . Scissors gear, 2. . . Sub gear, 23. . . Sub-tooth, 236. . . Inclined surface, 3. . . Main gear, 33. . . Main tooth, 334. . . Inclined surface, 5. . . Disc spring, 7. . . Mating gear, 731, 739. . . Tooth, 77. . . Tooth space,

Claims (2)

[Claims] 1. A main gear having main teeth meshing with a tooth groove of a mating gear, and a sub-gear arranged on the same rotation axis as the main gear and having sub-teeth meshing with the tooth groove of the mating gear together with the main gear. In the scissor gear in which the teeth of the mating gear are sandwiched by the main teeth and the sub teeth, biasing means for relatively bringing the main gear and the sub gear relatively close to each other in the direction of the rotation axis are provided. , An inclined surface which is inclined in a direction in which the thickness of the main teeth is reduced toward the sub-gear side is formed,
On the other hand, the sub-tooth of the sub-gear has an inclined surface inclined in a direction in which the thickness of the sub-tooth becomes thinner toward the main gear side. A scissors gear, wherein a portion of the scissor gear is configured to mesh with the tooth space of the mating gear in a state where the portions are superposed face to face. 2. A scissors gear according to claim 1, wherein said mating gear, main gear and sub gear are constituted by helical gears.