JP2000081114A - Gear transmission mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the occurrence of a backlash through structure being simple and decrease in size and to cope with the decrease in size and the increase of precision of the whole of a device to be loaded. SOLUTION: By exerting an engaging force when the gear of an object to be engaged is engaged, the tooth 11c of a spur gear 11 and the tooth 12c of the spur gear 12 are moved against the elastic force of each rod-form elastic body 14 so that the teeth car caused to coincide with each other from a state to be deviated from each other. In this case, the teeth 11c and 12c are engaged with each other such that a force is exerted in a circumferential direction on the tooth part of the gear being an object to be engaged. Namely, since the bending force (an elastic force) of the rod-form elastic body 14 is exerted as an elastic contact force on the engagement part, an engaging state freed from a backlash is produced, resulting in elimination of a backlash.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission mechanism applied to an information recording medium drive device such as an optical disk driver using a gear mechanism for transmitting a rotational force and capable of eliminating gear backlash.

[0002]

2. Description of the Related Art In recent years, as the capacity of optical discs has been increased, the precision of feeding in an optical pickup in an optical disc driver has been improved, and accordingly, the influence of backlash of gears constituting a feeding device has to be ignored. Is no longer possible. Various types of mechanisms for removing gear backlash have been proposed and implemented.

For example, in the backlash removing mechanism for a spur gear described in Japanese Patent Application Laid-Open No. 8-297929, FIG.
As shown in the figure, a gear is composed of two spur gears 1 and 2,
One spur gear 1 is provided with a claw 3 and this claw 3 is engaged with an engaging portion 4 provided on the other spur gear 2, and the teeth 1 a and 2 a of the two spur gears 1 and 2 are When they are displaced from each other and, as shown in FIG. 28, for example, when they are engaged with the rack 5, the spur gears 1 and 2 are caused to generate a circumferential elastic force by the claw portions 3 so that the teeth 5a of the rack 5 The backlash is removed by pressing the teeth 1a and 2a of the two spur gears 1 and 2 against the surface.

[0004]

In recent years, in the optical disk driver, since the thickness and the size of the optical disk driver have been reduced, not only the above-mentioned backlash is removed but also the size of the gear itself constituting the transmission mechanism is reduced. Is also needed.

In the backlash removing mechanism for a spur gear described in Japanese Patent Application Laid-Open No. 8-297929, a claw portion constituting the backlash removing mechanism is formed integrally with the gear to reduce the number of parts and the number of assembly steps. However, the material of the claw portion is determined by the material of the gear, and in order to provide sufficient elastic force in the circumferential direction, a groove or the like is provided around the claw portion to increase the amount of bending at the claw portion. Countermeasures are required, and the shape must be designed in consideration of the strength of the claws. Therefore, the degree of freedom in design is actually low, and it is difficult to reduce the size of the gear.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, to eliminate backlash by a simple and miniaturizable structure, and to reduce the size and accuracy of the entire device to be mounted. An object of the present invention is to provide a gear transmission mechanism that can cope with such a problem.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a construction in which a plurality of spur gears are connected to each other to form one transmission gear, and adjacent spur gears are connected by shifting their teeth. In the gear transmission mechanism, a mounting hole is provided in each of the two spur gears, an end portion of the rod-shaped elastic body is fixed to the mounting hole of each spur gear, and the mounting hole is connected to each spur gear. Are arranged so that the teeth in are shifted from each other in the circumferential direction.
At the time of meshing this gear with another gear, circumferential force acts on the teeth of the two spur gears due to the rod-shaped elastic body and meshes without backlash. Can be.

Further, the present invention provides a gear transmission mechanism which is constituted by connecting a plurality of spur gears to form one transmission gear and connecting the adjacent spur gears by shifting their teeth. A mounting hole is provided in each of the gears, one end of the rod-shaped elastic body is fixed to the mounting hole of one spur gear, and the other end of the rod-shaped elastic body is fixed to the mounting hole of the other spur gear. The spur gears are loosely fitted, and the mounting holes are arranged so that the teeth of each spur gear are shifted from each other in the circumferential direction. With this configuration, backlash can be removed in the same manner as described above, and the rod-like elasticity can be reduced. The work of attaching the body to the spur gear is simplified.

The present invention is also directed to a gear transmission mechanism in which a plurality of spur gears are connected to each other to form a single transmission gear, and the adjacent spur gears are connected by shifting their teeth. A mounting hole is provided in each of the gears, the end portion of the rod-shaped elastic body is loosely fitted into the mounting hole of each spur gear, and the mounting holes are further shifted so that the teeth of each spur gear are shifted from each other in the circumferential direction. With this configuration, backlash can be removed in the same manner as described above, and the operation of fixing the rod-shaped elastic body to the spur gear becomes unnecessary, and the mounting operation is further simplified.

Further, in the present invention, the two spur gears are adjacent to each other via a gap in which the rod-shaped elastic body can bend. With this configuration, a margin for bending of the rod-shaped elastic body is obtained. In addition, a circumferential force can be reliably applied to the teeth of the two spur gears made of the rod-shaped elastic body.

Further, according to the present invention, an end portion of the rod-shaped elastic body which is loosely fitted into the mounting hole is formed at an angle with respect to the other end of the rod-shaped elastic body. Even if there is no gap between spur gears like
Since a circumferential elastic force can be generated in the rod-shaped elastic body, the mechanism can be made thinner.

According to the present invention, the gear-facing side of the mounting hole is formed larger than the external side.
With this configuration, the rod-shaped elastic body can be bent on the gear-facing side of the mounting hole, and even if the gap between the spur gears is small as described above, a circumferential elastic force is generated in the rod-shaped elastic body. Therefore, the mechanism can be made thinner.

Further, the present invention relates to a gear transmission mechanism which is constituted by connecting a plurality of spur gears to form one transmission gear and connecting the adjacent spur gears by shifting their respective teeth. A mounting hole is provided in each of the three spur gears, which are stepped spur gears in which two spur gears having different diameters are integrated, and a rod-shaped elastic body is inserted into the mounting hole of each spur gear. The spur gears are fixed so that the teeth of each spur gear are displaced from each other in the circumferential direction. With this configuration, when this gear meshes with another gear, a step is formed by a rod-shaped elastic body. Since a circumferential force acts on the teeth of the spur gear and the adjacent spur gear to mesh with each other without play, backlash can be removed with a simple structure even with a stepped spur gear. Can be.

According to the present invention, there is provided a gear transmission mechanism in which a plurality of spur gears are connected to each other to form one transmission gear, and teeth of adjacent spur gears are connected by shifting each other. A mounting hole is provided in each of the three spur gears, each of which is a stepped spur gear in which two spur gears having different diameters are integrated, and a central portion of the rod-shaped elastic body is provided in the mounting hole of the intermediate spur gear. And the end portions of the rod-shaped elastic bodies are respectively fixed to the mounting holes of the spur gears on both sides of the intermediate spur gear, and the mounting holes are further shifted so that the teeth of each spur gear are shifted from each other in the circumferential direction. The backlash can be removed in the same manner as described above, and the operation of attaching the rod-shaped elastic body to the spur gear can be simplified.

According to the present invention, there is provided a gear transmission mechanism in which a plurality of spur gears are connected to each other to form one transmission gear, and teeth of adjacent spur gears are connected by shifting each other. A mounting hole is provided in each of the three spur gears, each of which is a stepped spur gear in which two spur gears having different diameters are integrated, and a central portion of the rod-shaped elastic body is provided in the mounting hole of the intermediate spur gear. And the end portions of the rod-shaped elastic body are loosely fitted into the mounting holes of the spur gears on both sides of the intermediate spur gear, and the mounting holes are further shifted so that the teeth of each spur gear are shifted from each other in the circumferential direction. The backlash can be removed in the same manner as described above, and the operation of attaching the rod-shaped elastic body to the spur gear can be simplified.

According to the present invention, there is provided a gear transmission mechanism in which a plurality of spur gears are connected to each other to form a single transmission gear, and the teeth of adjacent spur gears are connected by shifting each other. Are provided with mounting holes in each of the three spur gears, which are stepped spur gears in which two spur gears having different diameters are integrated, and a rod-shaped elastic body is loosely fitted in the mounting hole of each spur gear. Further, the mounting holes are provided such that the teeth of each spur gear are shifted from each other in the circumferential direction. With this configuration, backlash can be removed in the same manner as described above, and the rod-shaped elastic spur gear can be used. This eliminates the need for fixing work to the device, and further simplifies the mounting work.

Further, in the present invention, the three spur gears are adjacent to each other via a gap in which the rod-like elastic body can bend. With this configuration, a margin for bending of the rod-like elastic body is obtained. In addition, the force in the circumferential direction can be reliably applied to the teeth of the three spur gears made of the rod-shaped elastic body.

According to the present invention, the rod-shaped elastic member is formed by forming an angle between the rod-shaped elastic member provided on the intermediate spur gear and the rod-shaped elastic member provided on both spur gears. According to this configuration, even if there is no gap between the spur gears as described above, the elastic force in the circumferential direction can be generated in the rod-shaped elastic body, so that the thickness of the mechanism can be reduced.

According to the present invention, the gear-facing side of the mounting hole is formed larger than the outer side.
With this configuration, the rod-shaped elastic body can be bent on the gear-facing side of the mounting hole, and even if the gap between the spur gears is small as described above, a circumferential elastic force is generated in the rod-shaped elastic body. Therefore, the mechanism can be made thinner.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional front view of a gear transmission mechanism for explaining a first embodiment of the present invention, and FIG. 2 is a side sectional view of the gear transmission mechanism of FIG. 12
Have the same specifications except for the tooth width, each of which has a central hole 11a, 12a into which the support shaft 13 is inserted, and each of which has a center on a concentric circle (four in this example). ) Are provided with mounting holes 11b and 12b. In the pair of spur gears 11 and 12, opposing mounting holes 11 b and 12 b are provided with flexible rod-shaped elastic bodies 14.
Are fixed respectively.

As shown in FIG. 2, the two spur gears 11 and 12 are attached to a support shaft 13 with a gap S therebetween. The teeth 11c of the spur gear 12 and the teeth 12c of the spur gear 12 are mounted so as to be shifted from each other in the circumferential direction.

When the gear to be meshed (indicated by a two-dot chain line) is meshed with the gear transmission mechanism having the above-described structure, the meshing force at this time is received, and the teeth 11c of the spur gear 11 and the teeth 1 of the spur gear 12 are received.
2c moves against the elastic force of each rod-shaped elastic body 14 so as to match each other. Then, the teeth 11c and 12c mesh with each other so as to apply a circumferential force to the tooth portion of the gear to be meshed. The state of the rod-shaped elastic body 14 in this load state is determined by the teeth 11c of the spur gear 11 and the spur gear 1
When the second tooth 12c is shifted from the second tooth 12c, the two spur gears 11 and 12 as shown in FIG.
A load is applied to the rod-shaped elastic body 14 from above, and the central portion 14a of the rod-shaped elastic body 14 bends in the gap S. Since the bending force acts on the meshing portion as an elastic contact force, a meshing state without rattling is attained, whereby backlash can be eliminated.

The gap S between the spur gears 11 and 12, or the teeth 11c of the spur gear 11 and the spur gear 12
The amount of deviation from the tooth 12c is appropriately changed and set according to the use conditions of the gear transmission mechanism. For example, the rod-shaped elastic body 14 is attached so that the teeth 11c and the teeth 12c substantially coincide with each other in a no-load state, and the teeth 11c and 12c of the spur gears 11 and 12 are attached.
May be applied in the circumferential direction of the gear transmission mechanism so as to greatly shift the gears so as to mesh with the gear to be meshed.

The shape of the rod-like elastic body is not only the above-mentioned round rod-like body but also a square rod-like rod-like elastic body 15 as shown in FIG. 4 or a plate-like rod-like elastic body as shown in FIG. The elastic body 16 or the like may be used, and the number of the elastic bodies 16 may be appropriately selected according to the use conditions and specifications of the gear transmission mechanism.

The mounting holes 11 for the spur gears 11 and 12
The b and 12b do not penetrate the gear as shown in FIG. 2, but as shown in FIG.
b ', 12b', and the mounting holes 11b, 1
The formation directions of 2b, 11b ', and 12b' may not be parallel to the center axis of the support shaft 13 of the spur gears 11, 12 as described above, but may be formed to be inclined with respect to the center axis.

The material of the rod-like elastic members 14, 15, 16 is not limited to metal and resin, and any material that can provide an elastic force can be used. Further, as a method of fixing the rod-like elastic members 14, 15, 16 to the spur gears 11, 12, it is conceivable to fix the rod-like elastic members 14, 15, 16 by insert molding when forming the gears.

FIG. 7 is a partial front sectional view of a gear transmission mechanism for explaining a second embodiment of the present invention, and FIG. 8 is a side sectional view of the gear transmission mechanism of FIG. In the following description of each embodiment, members corresponding to members described in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

7 and 8, a pair of spur gears 11,
A plurality (four in this example) of mounting holes 11b, 12b each having a center located on a concentric circle are provided in the spur gear 11, and one end 14b of the rod-shaped elastic body 14 is provided in the mounting hole 11b of one of the spur gears 11. Is loosely fitted, and the mounting hole 1 for the other spur gear 12 is
The other end 14c of the rod-shaped elastic body 14 is fixed to 2b. When the state of the rod-shaped elastic body 14 in the load state is changed from the state in which the teeth 11c of the spur gear 11 and the teeth 12c of the spur gear 12 are shifted to each other, as shown in an explanatory view of FIG. A load is applied to the rod-shaped elastic body 14 from the rods 11 and 12, so that one end 14b of the rod-shaped elastic body 14 is placed in the mounting hole 11b and further a central part 14a of the rod-shaped elastic body 14.
Bend in the gap S. Since the bending force acts on the meshing portion as an elastic contact force, a meshing state without rattling is attained, whereby backlash can be eliminated.

With this configuration, according to the configuration of the second embodiment, only one end of the rod-shaped elastic body 14 is connected to the spur gear 1.
2 simplifies the mounting operation.

FIG. 10 is a partial front sectional view of a gear transmission mechanism for explaining a third embodiment of the present invention, and FIG.
FIG. 3 is a side sectional view of the gear transmission mechanism of FIG.
A plurality (four in this example) of mounting holes 11b and 12b having respective centers located on concentric circles are provided in the mounting holes 11b and 12b. The both ends 14b and 14c of 14 are loosely fitted. When the state of the rod-shaped elastic body 14 in the load state is changed from the state in which the teeth 11c of the spur gear 11 and the teeth 12c of the spur gear 12 are shifted to each other, as shown in an explanatory view of FIG. A load is applied to the rod-like elastic body 14 from the rods 11 and 12, and both ends 14b and 14c of the rod-like elastic body 14 are further attached to the rod-like elastic bodies 14 in the mounting holes 11b and 12b.
Is bent in the gap S. Since the bending force acts on the meshing portion as an elastic contact force, a meshing state without rattling is attained, whereby backlash can be eliminated.

With this configuration, according to the configuration of the third embodiment, the end of the rod-shaped elastic body 14 is connected to the spur gears 11 and 1.
The work for fixing the fixing work to the second work is not required, and the mounting work is further simplified.

FIG. 13 is a side sectional view of a main part of a gear transmission mechanism for explaining a fourth embodiment of the present invention.
In the fourth embodiment, similarly to the second embodiment, one end 14b of the rod-shaped elastic body 14 is loosely fitted in the mounting hole 11b of one spur gear 11, and is fitted in the mounting hole 12b of the other spur gear 12. Although the other end 14c of the rod-shaped elastic body 14 is fixed, the second embodiment differs from the second embodiment in that the opposite sides of the pair of spur gears 11 and 12 are in contact with each other and the other end 14c of the rod-shaped elastic body 14 is fixed. There is a difference in that the hole 12b is formed in the spur gear 11 so as to have an angle α with respect to the other mounting holes 11b.

With this configuration, according to the configuration of the fourth embodiment, even if there is no gap between the pair of spur gears 11 and 12, the rod-shaped elastic body 14 bends in a loaded state, so that both flat gears 11 and 12 are bent. An elastic force acts on the gears 11 and 12 in the circumferential direction, and acts as an elastic contact force on the meshing portion in the same manner as described above, so that the gears 11 and 12 are in a meshing state without rattling, whereby backlash can be eliminated. Therefore, according to the configuration of the fourth embodiment, the pair of spur gears 11 and 12
By eliminating the gap between them, the overall mechanism can be made thinner.

FIG. 14 is a side sectional view of a main part of a gear transmission mechanism for explaining a fifth embodiment of the present invention.
In the fifth embodiment, as in the third embodiment, the rod-like elastic bodies 1 are provided in the mounting holes 11b and 12b of the two spur gears 11 and 12.
4, both ends 14b and 14c are loosely fitted. However, the third embodiment differs from the third embodiment in that opposing sides of a pair of spur gears 11 and 12 are in contact with each other and one mounting hole 12b is connected to the other mounting hole 1
There is a difference in that the spur gear 12 is formed to have an angle β with respect to 1b.

With this configuration, according to the configuration of the fifth embodiment, even if there is no gap between the pair of spur gears 11 and 12, the rod-shaped elastic body 14 bends in a loaded state, so that both flat gears 11 and 12 are bent. An elastic force acts on the gears 11 and 12 in the circumferential direction, and acts as an elastic contact force on the meshing portion in the same manner as described above, so that the gears 11 and 12 are in a meshing state without rattling, whereby backlash can be eliminated. Therefore, the fourth
Since a gap can be eliminated between the pair of spur gears 11 and 12 as in the embodiment, the entire mechanism can be made thinner.

FIG. 15 is a side sectional view of a main part of a gear transmission mechanism for explaining a sixth embodiment of the present invention.
In the sixth embodiment, similarly to the first embodiment, the pair of spur gears 11 and 12 face opposite mounting holes 11.
The ends of the rod-shaped elastic body 14 having flexibility are fixed to b and 12b, respectively. However, the first embodiment differs from the first embodiment in that each mounting hole 11b,
The diameter of the enlarged diameter portion 11d, 1
There is a difference in forming 2d.

With this configuration, according to the configuration of the sixth embodiment, even when the gap S between the pair of spur gears 11 and 12 is small, the rod-shaped elastic body 14 is in the central portion 1 in a loaded state.
4a bends at the enlarged diameter portions 11d and 12d of the spur gears 11 and 12, an elastic force acts on the spur gears 11 and 12 in the circumferential direction, and an elastic contact force is applied to the meshing portion in the same manner as described above. As a result, it becomes a meshing state without play,
This can eliminate backlash. Therefore, according to the configuration of the sixth embodiment, by reducing the gap S between the pair of spur gears 11 and 12, it is possible to reduce the thickness of the entire mechanism.

FIG. 16 is a side sectional view showing a modification of the sixth embodiment. The shape of the enlarged portion is different from that of the sixth embodiment. In FIG. 15, the enlarged portions 11d and 12d are rectangular in cross section. In the example of FIG. 16, each of the mounting holes 11b,
The enlarged diameter portions 11d and 12d are formed by forming a slope T on the side adjacent to the gear in 12b.

FIG. 17 is a side sectional view of a gear transmission mechanism for explaining a seventh embodiment of the present invention. The spur gears are a set of three spur gears. This is a stepped spur gear in which two spur gears 21a ', 21a "are integrated. Further, on both sides of the central spur gear 21, spur gears 22 having the same diameter as the diameter of the adjacent spur gears 21a', 21a" are provided.
23 is provided. Spur gears 21, 22, 23
Have the same specifications except for the tooth width.
The center holes 21a, 22a, and 23a into which the support shafts 24 are inserted are provided at the centers of the mounting holes 21b and 23, respectively.
b and 23b are provided. Mounting holes 21b, 22
b and 23b are provided at corresponding positions, and a flexible rod-like elastic body 25 is inserted into the mounting holes 21b, 22b and 23b, and the central portion 25a of the rod-like elastic body 25 is located in the central spur gear 21. Both ends 25b and 25c of the rod-shaped elastic body 25 are fixed to the mounting holes 21b and the mounting holes 22b and 23b of the spur gears 22 and 23 on both sides.

The two spur gears 21, 22, and 23 are respectively attached to the support shaft 24 with a gap S therebetween. Each of the rod-like elastic bodies 25 has a central flat spur in a no-load state as in the state shown in FIG. The teeth 21 c ′ of one spur gear 21 a ′ of the gear 21 are attached to the teeth 22 c of the adjacent spur gear 22 so as to be circumferentially offset from each other, and the other spur gear 21 a ″ of the central spur gear 21. Teeth 21
c "are attached to the teeth 23c of the adjacent spur gear 23 so as to be circumferentially shifted from each other.

When a gear to be meshed (indicated by a two-dot chain line) is meshed with the gear transmission mechanism having the above-described structure, the meshing force at this time is received, and each spur gear 21 in the central spur gear 21 is received.
The teeth 21c 'and 21c "of the a' and 21a" and the teeth 22c and 23c of the spur gears 22 and 23 on both sides move against the elastic force of the rod-shaped elastic bodies 25 so as to match each other. . Then, the teeth 21c ′ and the teeth 22c, and the teeth 21c ″ and the teeth 23c mesh with each other so as to apply a force in the circumferential direction to the tooth portion of the gear to be meshed. As shown in the explanatory view of FIG. 18 showing the state of each part, each tooth 21c ′, 21c ″, 22c, 23
When c is shifted from the shifted state to the matched state, a load is applied from each spur gear 21 (21a ′, 21a ″), 22, 23 to the rod-shaped elastic body 25, and the rod-shaped elastic body 25 bends in each gap S. Since the bending force acts on the meshing portion as an elastic contact force, a meshing state without rattling is obtained, and thereby backlash can be eliminated.

The gap S between the gears 21, 22, 23, or the teeth 21c 'and 21c "and the teeth 22
The amount of deviation from c and 23c can be changed as appropriate according to the conditions of use of the gear transmission mechanism. For example, the rod-shaped elastic body 25 is attached so that the teeth 21 c ′ and 21 c ″ substantially match the teeth 22 c and 23 c in a no-load state.
A force may be applied in the circumferential direction of the gear transmission mechanism so that the gears c ', 21c "and the teeth 22c, 23c are largely displaced from each other to mesh with the gear to be meshed.

The shape of the rod-like elastic body may be a round rod-like body, a square rod-like body, a plate-like body, or the like. Is selected as appropriate.

The mounting holes 21b, 22b, 23b of the spur gears 21, 22, 23 do not penetrate the gears as shown in FIG. 17, but are receiving holes for receiving a rod-shaped elastic body having a concave shape. And mounting holes 21b, 2
The direction in which the 2b and 23b are formed may not be parallel to the center axis of the support shaft 24 as described above, but may be formed to be inclined with respect to the center axis.

The material of the rod-shaped elastic body 25 is not limited to metal and resin, but may be any material capable of giving an elastic force. Further, as a method of fixing the rod-like elastic body 25 to the spur gears 21, 22, 23, it is conceivable to fix the rod-like elastic body 25 by insert molding at the time of gear formation.

FIG. 19 is a side sectional view of a gear transmission mechanism for explaining an eighth embodiment of the present invention. In the following description of each embodiment, members corresponding to members described in the seventh embodiment are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 19, the central portion 25a of the rod-shaped elastic body 25 is loosely fitted in the mounting hole 21b of the central spur gear 21, and the mounting holes 22b, 23 of the spur gears 22, 23 on both sides.
The two ends 25b and 25c of the rod-shaped elastic body 25 are fixed to b. For this reason, when the state of the rod-shaped elastic body 25 in the load state is changed from the state in which the teeth 21c ′ and 21c ″ and the teeth 22c and 23c are shifted to each other, as shown in an explanatory diagram of FIG. A load is applied to the rod-like elastic body 25 from the members 21, 22, 23, and the rod-like elastic body 25 bends in a portion between the gaps S. The bending force acts as an elastic contact force on the meshing portion, so that the meshing state without rattling. Becomes
This can eliminate backlash.

With this configuration, according to the configuration of the eighth embodiment, only the central portion 25a of the rod-shaped elastic body 25 needs to be fixed to the central spur gear 21, and the mounting operation is simplified.

FIG. 21 is a side sectional view of a gear transmission mechanism for explaining a ninth embodiment of the present invention. In this ninth embodiment, a mounting hole 21b for a central spur gear 21 is shown.
The central portion 25a of the rod-shaped elastic body 25 is fixed to the upper end, and both ends 25b, 25c of the rod-shaped elastic body 25 are loosely fitted into the mounting holes 22b, 23b of the spur gears 22, 23 on both sides. For this reason, the state of the rod-shaped elastic body 25 in the loaded state is the tooth 2
When the teeth 1c ′ and 21c ″ and the teeth 22c and 23c are shifted from each other to a matching state, a load is applied from the spur gears 21, 22, and 23 to the rod-shaped elastic body 25 as shown in the explanatory view of FIG. The rod-like elastic body 25 bends at both ends 25b and 25c from the gap S. The flexing force acts on the meshing portion as an elastic contact force, so that the meshing state without rattling is achieved, thereby eliminating backlash. can do.

With this configuration, according to the configuration of the ninth embodiment, both ends 25b, 25c of the rod-shaped elastic body 25 are provided.
Only need to be fixed to the spur gears 22 and 23 on both sides.
The mounting operation is simplified as in the embodiment.

FIG. 23 is a side sectional view of a gear transmission mechanism for explaining a tenth embodiment of the present invention.
In the embodiment, the central portion 25a of the rod-shaped elastic body 25 is provided in the mounting hole 21b in the central spur gear 21, and both ends 25b and 25c of the rod-shaped elastic body 25 are provided in the mounting holes 22b in the spur gears 22 and 23 on both sides. , 23b. For this reason, the state of the rod-shaped elastic body 25 in the loaded state is determined by the teeth 21c ′ and 21c ″ and the teeth 22c,
When the state is shifted from the state where 23c is shifted,
24, spur gears 21, 22, 23
A load is applied to the rod-like elastic body 25 from the
Will bend over substantially the entire area. Since the bending force acts on the meshing portion as an elastic contact force, a meshing state without rattling is attained, whereby backlash can be eliminated.

With this configuration, according to the configuration of the tenth embodiment, since the fixing operation of the rod-shaped elastic body 25 is not required, the mounting operation is further simplified.

FIG. 25 is a side sectional view of a gear transmission mechanism for explaining an eleventh embodiment of the present invention.
In the embodiment, similarly to the ninth embodiment, the central spur gear 2
The central portion 25a of the rod-shaped elastic body 25 is inserted into the mounting hole 21b
Are fixed, and the mounting holes 22 for the spur gears 22 and 23 on both sides are fixed.
The two ends 25b and 25c of the rod-shaped elastic body 25 are loosely fitted to the rods b and 23b.
The mounting holes 22b and 23b in the spur gears 22 and 23 on both sides where the spur gears 22 and 23 are in contact with both sides of the first spur gear 1 and both ends 25b and 25c of the rod-shaped elastic body 25 are loosely fitted.
However, there is a difference in that it is formed so as to have an angle α with respect to the mounting hole 21b in the central spur gear 21.

With this configuration, according to the configuration of the eleventh embodiment, even when there is no gap between the spur gears 21, 22, and 23, the rod-shaped elastic body 25 is kept at the two end portions 2 under load.
Since the spur gears 21, 22 and 23 are bent at the portions 5b and 25c, an elastic force in the circumferential direction acts on the spur gears 21, 22, and 23, and acts as an elastic contact force on the meshing portion in the same manner as described above. It is in an engaged state, so that backlash can be eliminated. Thus, according to the configuration of the eleventh embodiment, the thickness of the entire mechanism can be reduced by eliminating the gap between the spur gears 21, 22, and 23.

FIG. 26 is a side sectional view of a gear transmission mechanism for explaining a twelfth embodiment of the present invention.
In the embodiment, the mounting hole 21b for the central spur gear 21 is provided.
The central portion 25a and one end portion 25b of the rod-shaped elastic body 25 are fixed to the mounting hole 22b of the spur gear 22 adjacent to one side (the left side of the drawing in the present example) of the central spur gear 21, The other end 25c of the rod-shaped elastic body 25 is loosely fitted in the mounting hole 23b of the other side spur gear 23, and a small gap S is provided between the central spur gear 21 and the one side spur gear 22.
The central spur gear 21 and the other spur gear 23 are in contact with each other. Further, the diameter of the mounting holes 22b and 23b in the spur gears 22 and 23 on both sides is made larger than the outer diameter on the side adjacent to the central spur gear 21 to form the enlarged diameter portions 22d and 23d.

With this configuration, according to the configuration of the twelfth embodiment, even if there is not a sufficient gap S between the spur gears 21, 22, and 23, the rod-shaped elastic member 25 can be maintained in a loaded state.
Are bent at the enlarged diameter portions 22d and 23d of the both end portions 25b and 25c.
Has an elastic force in the circumferential direction and acts as an elastic force on the meshing portion in the same manner as described above, so that the meshing state is free from rattling, and thereby backlash can be removed. Therefore, according to the structure of the twelfth embodiment, the entire mechanism S can be made thinner by reducing the entire gap S between the spur gears 21, 22, and 23.

It is also conceivable to adopt a combination of the characteristic configurations of the embodiments as appropriate depending on the design, specifications, and the like.

[0059]

As described above, according to the present invention,
In a gear transmission mechanism composed of two spur gears or a gear transmission mechanism composed of a stepped spur gear and two spur gears, a circumferential force is applied to the gear teeth by a rod-shaped elastic body. As a result, the tooth portions are meshed without rattling at the meshing portion, so that the backlash can be removed with a simple structure.

As described above, since the backlash can be removed by the simple and miniaturizable structure, a gear transmission mechanism capable of coping with the miniaturization and high accuracy of the whole device to be mounted is provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a front partial cross-sectional view of a gear transmission mechanism for explaining a first embodiment of the present invention.

FIG. 2 is a side sectional view of the gear transmission mechanism according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of the gear transmission mechanism according to the first embodiment of the present invention.

FIG. 4 is a perspective view for explaining another installation example of the rod-shaped elastic body according to the first embodiment of the present invention.

FIG. 5 is a perspective view for explaining another installation example of the rod-shaped elastic body according to the first embodiment of the present invention.

FIG. 6 is a sectional view showing another example of the mounting hole according to the first embodiment of the present invention.

FIG. 7 is a partial front sectional view of a gear transmission mechanism for explaining a second embodiment of the present invention.

FIG. 8 is a side sectional view of a gear transmission mechanism according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of a gear transmission mechanism according to a second embodiment of the present invention.

FIG. 10 is a front partial sectional view of a gear transmission mechanism for explaining a third embodiment of the present invention.

FIG. 11 is a side sectional view of a gear transmission mechanism according to a third embodiment of the present invention.

FIG. 12 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of a gear transmission mechanism according to a third embodiment of the present invention.

FIG. 13 is a side sectional view of a main part of a gear transmission mechanism for explaining a fourth embodiment of the present invention.

FIG. 14 is a side sectional view of a main part of a gear transmission mechanism for describing a fifth embodiment of the present invention.

FIG. 15 is a side sectional view of a main part of a gear transmission mechanism for explaining a sixth embodiment of the present invention.

FIG. 16 is a side sectional view showing a modification of the sixth embodiment of the present invention.

FIG. 17 is a side sectional view of a main part of a gear transmission mechanism for explaining a seventh embodiment of the present invention.

FIG. 18 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of a gear transmission mechanism according to a seventh embodiment of the present invention.

FIG. 19 is a side sectional view of a main part of a gear transmission mechanism for explaining an eighth embodiment of the present invention.

FIG. 20 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of a gear transmission mechanism according to an eighth embodiment of the present invention.

FIG. 21 is a side sectional view of a main part of a gear transmission mechanism for explaining a ninth embodiment of the present invention.

FIG. 22 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of a gear transmission mechanism according to a ninth embodiment of the present invention.

FIG. 23 is a side sectional view of a main part of a gear transmission mechanism for explaining a tenth embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a state of a rod-shaped elastic body in a load state of a gear transmission mechanism according to a tenth embodiment of the present invention.

FIG. 25 is a side sectional view of a main part of a gear transmission mechanism for explaining an eleventh embodiment of the present invention.

FIG. 26 is a side sectional view of a main part of a gear transmission mechanism for explaining a twelfth embodiment of the present invention.

FIG. 27 is an explanatory view showing a main part of a conventional gear transmission mechanism.

FIG. 28 is an explanatory view showing the meshing state of the teeth in the conventional gear transmission mechanism of FIG. 27;

[Explanation of symbols]

11, 12, 22, 23 Spur gear 11a, 12a, 21a, 22a, 23a Central hole 11b, 12b, 11b ', 12b', 21b, 22
b, 23b Mounting holes 11c, 12c, 21c ', 21c ", 22c, 23c
Spur gear teeth 11d, 12d, 22d, 23d Spur gear enlarged diameter portion 13, 24 Support shafts 14, 15, 16, 25 Rod-like elastic body 14a, 25a Central part of rod-like elastic body 14b, 14c, 25b, 25c Rod-like elasticity End of body 21 Stepped spur gear 21a ', 21a "Spur gears of different diameters constituting stepped spur gear S Gap

Claims (13)

[Claims] 1. A gear transmission mechanism comprising a plurality of spur gears connected to form a single transmission gear and connected by shifting the teeth of adjacent spur gears to each other. Mounting holes in each of the spur gears, fixing the end portions of the rod-shaped elastic bodies to the mounting holes of the respective spur gears, and setting the mounting holes such that the teeth of the respective spur gears are shifted from each other in the circumferential direction. Characteristic gear transmission mechanism. 2. A gear transmission mechanism in which a plurality of spur gears are connected to each other to form a single transmission gear and are connected by shifting teeth of adjacent spur gears respectively. A mounting hole is provided on one of the spur gears, one end of the rod-shaped elastic body is fixed to the mounting hole of one spur gear, and the other end of the rod-shaped elastic body is loosely fitted into the mounting hole of the other spur gear. A gear transmission mechanism, wherein the mounting holes are arranged such that teeth of each spur gear are shifted from each other in a circumferential direction. 3. A gear transmission mechanism in which a plurality of spur gears are connected to each other to form one transmission gear, and are connected by shifting the teeth of adjacent spur gears respectively. Mounting holes, the end portions of the rod-shaped elastic bodies are loosely fitted into the mounting holes of the respective spur gears, and the mounting holes are set such that the teeth of the respective spur gears are shifted from each other in the circumferential direction. A gear transmission mechanism. 4. The gear transmission mechanism according to claim 1, wherein the two spur gears are adjacent to each other via a gap in which the rod-shaped elastic body can bend. 5. The rod-shaped elastic body according to claim 2, wherein an end portion of the rod-shaped elastic body that fits loosely into the mounting hole is formed at an angle to the other end of the rod-shaped elastic body. Gear transmission mechanism. 6. A gear-facing side of the mounting hole,
2. The structure according to claim 1, wherein the outer side is formed larger than the outer side.
The gear transmission mechanism according to any one of claims 1 to 5. 7. A gear transmission mechanism in which a plurality of spur gears are connected to each other to form one transmission gear, and the adjacent spur gears are connected by shifting their respective teeth, wherein an intermediate spur gear has a diameter of A mounting hole is provided in each of the three spur gears, which are stepped spur gears in which two different spur gears are integrated, and a rod-shaped elastic body is inserted and fixed in the mounting hole of each spur gear. A gear transmission mechanism, wherein the mounting holes are provided such that teeth of each spur gear are shifted from each other in a circumferential direction. 8. A gear transmission mechanism in which a plurality of spur gears are connected to each other to form a single transmission gear, and the adjacent spur gears are connected by shifting their respective teeth. A mounting hole is provided in each of the three spur gears, which are stepped spur gears in which two different spur gears are integrated, and the central portion of the rod-shaped elastic body is loosely fitted into the mounting hole of the intermediate spur gear. Then, the end portions of the rod-shaped elastic body are fixed to the mounting holes of the spur gears on both sides of the intermediate spur gear, respectively, and the mounting holes are installed so that the teeth of the spur gears are shifted from each other in the circumferential direction. A gear transmission mechanism. 9. A gear transmission mechanism in which a plurality of spur gears are connected to each other to form one transmission gear, and the spur gears of adjacent spur gears are connected by shifting each other. A mounting hole is provided in each of the three spur gears, which are stepped spur gears in which two different spur gears are integrated, and the central portion of the rod-shaped elastic body is fixed to the mounting hole of the intermediate spur gear. The end portions of the rod-shaped elastic body are loosely fitted into the mounting holes of the spur gears on both sides of the intermediate spur gear, and the mounting holes are installed such that the teeth of the spur gears are shifted from each other in the circumferential direction. A gear transmission mechanism. 10. A gear transmission mechanism in which a plurality of spur gears are connected to each other to form a single transmission gear, and teeth of adjacent spur gears are connected by shifting each other. A mounting hole is provided in each of the three spur gears, which are stepped spur gears in which two different spur gears are integrated, and a rod-shaped elastic body is loosely fitted in the mounting hole of each spur gear. A gear transmission mechanism in which holes are provided such that teeth of each spur gear are shifted from each other in a circumferential direction. 11. The gear transmission according to claim 7, wherein the three spur gears are adjacent to each other via a gap in which the rod-shaped elastic body can bend. mechanism. 12. The bar-shaped elastic member is formed by forming an angle between a bar-shaped elastic member provided on an intermediate spur gear and a bar-shaped elastic member provided on both spur gears. The gear transmission mechanism according to claim 9 or 10, wherein 13. The gear transmission mechanism according to claim 7, wherein a side of the mounting hole facing the gear is formed larger than an outer side.