JP3078977B2 - Backlash removal device for gear transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlash removing device for a transmission used in connection with a motor shaft for reducing or increasing the speed of, for example, a geared motor.

[0002]

2. Description of the Related Art For example, a geared motor or the like is provided with a gear transmission for speed reduction. In a gear transmission 70 as shown in FIG. 16, a driving force is transmitted from a first gear 72 fixed to an input shaft 71. The driving force of the first gear 72 is transmitted from the first transmission gear 73 meshing with the first gear 72 to the second transmission gear 75 via the transmission shaft 74, and further via the second gear 76. The rotation of the rotation is transmitted to the output shaft 77. In this way, the gear transmission is decelerated by gears,
Problems such as rattling and generation of abnormal noise when the gears mesh with each other are caused by the backlash between the gears. In some cases, a rotary encoder is juxtaposed to a rotating shaft of a gear transmission to detect a rotation amount and perform various system controls based on the detected data. However, if there is backlash, the rotary encoder does not accurately detect the amount of rotation, and the system cannot be controlled.

Therefore, as shown in FIG. 16, between a first gear 72 and a second gear 76, a first and a second backlash gear connected by a connecting shaft 78 for removing backlash. 79 and 80 are juxtaposed. The second backlash gear 80 is fixed by a fixing bolt 81, and when the backlash is removed, the two backlash gears 79, 80 are rotated in opposite directions. That is, as shown in FIG. 17, for example, the first backlash gear 79 is rotated clockwise to remove the backlash between the first gear 72 and the second backlash gear 80 as shown in FIG. By rotating in the counterclockwise direction, the backlash with the second gear 76 is eliminated. Then, in this state, the second backlash gear 80 is fixed by the fixing bolt 81. Then, the driving force of the input shaft 71 is transmitted to the output shaft 77 with the backlash removed.

[0004]

However, since the backlash is not always constant and changes gradually depending on the temperature and humidity, the degree of reduction of the gear teeth, and the like, even if the backlash is fixed by the fixing bolt 81 as described above, Had to be adjusted accordingly. Further, even if the gear transmission is firmly tightened with the fixing bolt 81, the gear transmission may be loosened due to the vibration of the gear transmission, and it is necessary to periodically retighten the gear transmission.

An object of the present invention is to provide a backlash removing device for a gear transmission which eliminates backlash of gears of a gear transmission and can maintain a state of zero backlash even when operating conditions change.

[0006]

Means for Solving the Problems The present inventors in order to solve the aforementioned problem, the invention of claim 1, first a first gear fixed to the input shaft, which meshes with the first gear The transmission gear is mounted on the transmission shaft side and the second transmission gear is mounted on the transmission shaft side.
Transmission gear is mounted and meshed with a second gear fixed to the output shaft to transmit the rotation of the input shaft side to the output shaft side at a variable speed. and it is interposed a torque applying means for applying a relatively opposite direction of the torque for both backlash gears between the first second backlash gear that backlash gear and the second gear mesh with meshing, the torque The applying means is provided with the one battery.
It is fixed coaxially with the rotation axis of the crash gear and
Screw member that meshes with one of the backlash gears,
By the urging members for urging the lash gears in opposite directions
The gist is that it is configured .

According to a second aspect of the present invention, in the gear transmission according to the first aspect of the present invention, the urging member includes the two backlashes.
The gist is constituted by a spring member suspended between the gears . Further, in the gear transmission of a second invention is characterized in the invention of claim 3, wherein the torque applying means includes a bending moment applying means for applying a bending moment to <br/> I member when the bending in the spring member The gist is further provided with spring member fixing means for fixing in a state where a moment is applied.

[0008]

According to the above construction, in the first and second aspects of the present invention, the driving force of the gear transmission is changed from the first gear fixed to the input shaft to the first transmission gear, the transmission shaft, and the second transmission gear. , And the gears are sequentially transmitted to the output shaft and transmitted to the output shaft.
On the other hand, a backlash gear meshing with the first gear and a backlash gear meshing with the second gear are torqued in opposite directions by torque applying means, so that the backlash of each gear is removed. In addition , the two backlash gears are relatively rotated in opposite directions by a screw member fixed coaxially with the rotation axis of one of the backlash gears and meshing with the other backlash gear. When both the backlash gears are urged outward from the inside by the urging member, the urging force is converted into a torque for rotating the two backlash gears relatively in opposite directions by a screw, and the backlash of each gear is removed.

According to the third aspect of the present invention, the spring member suspended between the two backlash gears is bent by the bending moment applying means to generate a torque for rotating the two backlash gears in opposite directions. Then, if the spring member is fixed in a bent state by the spring member fixing means, since the torque is constantly generated in both the backlash gears, the backlash of each gear is removed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a backlash removing device for a gear transmission according to the present invention will be described below in detail with reference to the drawings. (Embodiment 1) Embodiment 1 will be described with reference to FIGS.
As shown in FIG. 1, an input shaft 2 of a speed reducer 1 which is a gear transmission is connected to a motor shaft (not shown) so that driving from a motor is transmitted and rotation is transmitted to an output shaft 3 side. The reduction gear 1 has an input shaft frame 4 and an output shaft frame 5
Protected by In the following description, the input shaft 2 side is referred to as a rear side, and the output shaft 3 side is referred to as a front side. The right hand side is referred to as the right side and the left hand side is referred to as the left side when viewed from the rear side.

The input shaft 2 is inserted through an opening 4 a formed at the rear end of the input shaft frame 4, and is rotatably supported by a bearing 6. The input shaft frame 4 is formed in a bowl shape and has a large opening on the front side. Input shaft frame 4
An engagement portion 4b with the output shaft frame 5 is formed at the front end portion of. Bearing flanges 11 and 12 having a U-shaped cross section are provided on the inner surface side of the input shaft frame 4 and on both left and right sides of the insertion hole 5.
Are formed so as to protrude toward the front side. An oil seal 7 is interposed between the input shaft 2 and the rear end of the opening 4a.

At the tip of the input shaft 2, a first gear 13 is formed. The rotation center of the first gear 13 formed of a spur gear is formed so as to coincide with the axis of the input shaft 2. The number of teeth of the first gear 13 is 26, and the module is 1.5.
It has been.

The output shaft 3 is mounted in the insertion hole 5 a of the output shaft frame 5 at a position facing the front of the input shaft 2. The output shaft frame 5 is formed in a cylindrical shape, and has a large opening on the rear side. Bearing flanges 17 and 18 having a U-shaped cross section are formed on the inner surface side of the output shaft frame 5 on both left and right sides of the insertion hole 5a so as to protrude rearward. A lid 8 is fixed to the insertion hole 5a of the output shaft frame 5 with a bolt 9, so as to close the insertion hole 5a. An oil seal 10 is interposed between the lid 8 and the output shaft 3. An engagement portion 5b with the input shaft frame 4 is formed at the rear end edge of the output shaft frame 5.
The output shaft frame 5 and the input shaft frame 4
The gears b and 5b are engaged with each other to form an outer device frame 19 of the speed reducer 1.

The output shaft 3 is rotatably supported by a bearing 14 of the output shaft frame 5 at a position coinciding with the axis of the input shaft 2, and has a through hole 5 a formed in the output shaft frame 5 at the tip end.
It protrudes more outward. At the rear end of the output shaft 3, a second gear 15 composed of a spur gear having a larger number of teeth and a larger module than the first gear 13 is formed. The number of teeth of the second gear 15 is 40, and the module is 1.5.
A mounting leg 20 is formed below the input shaft frame 4 to support the speed reducer 1.

Bearings 21 and 22 are provided between bearing flanges 11 and 17 on the left side (downward in FIG. 1) of both shaft frames 4 and 5.
The transmission shaft 23 is rotatably mounted via the. Near the rear end of the transmission shaft 23, a first transmission gear 24 made of a spur gear meshing with the first gear 13 is fixed.
A part of the teeth 25 of the first gear 13 and a part of the teeth 26 of the first transmission gear 24 are always in mesh with each other.
A backlash is formed between 3 and 24. The number of teeth of the first transmission gear 24 is 33, and the module is 1.5.

A second transmission gear 27, which is a spur gear meshing with the second gear 15, is fixed to the end of the transmission shaft 23. The number of teeth of the second transmission gear 27 is 20, and the module is 1.5. A part of the teeth 29 of the second transmission gear 27 and a part of the teeth 28 of the second gear 15 are always in mesh with each other, and a backlash is formed between the two gears 15 and 27.

On the other hand, between the bearing flanges 12 and 18 on the right (upper in FIG. 1) of the two shaft frames 4 and 5, a bearing 3 is provided.
A connection shaft 32 serving as a screw member (torque applying means) is rotatably mounted via 0 and 31. A right-hand thread groove 32 a is formed on the outer periphery of the front side of the connecting shaft 32. Near the rear end of the connecting shaft 32, a first backlash gear 33 formed of a spur gear meshing with the first gear 13 is fixed. A part of the teeth 25 of the first gear 13 and a part of the teeth 34 of the first backlash gear 33 are always in mesh with each other, and a backlash is formed between the two gears 13, 33. The number of teeth and the module of the first backlash gear 33 are the same as those of the first transmission gear 24.

[0018] A front end side of the connecting shaft 32, the said screw groove 32a periphery second backlash gear 35 made of a spur gear that meshes with the second gear 15 is fixed. The second backlash gear 35 is formed in an annular shape, and a right-hand thread groove 35a is formed on the inner peripheral surface. The second backlash gear 35 second transmission gear 27
The number of teeth and the module are the same. Part of the teeth 37 of the second backlash gear 35 and the teeth of the second gear 15
The part of the 2 8 has a constant engagement state, the gears 1
A backlash is formed between 5 and 35.

The screw groove 32a of the connecting shaft 32 and the screw groove 35a of the second backlash gear 35 are engaged with each other via a plurality of steel balls 36. That is, the connection shaft 32 and the second backlash gear 35 are ball screws,
When the second backlash gear 35 moves back and forth along the connection shaft 32, friction between the second backlash gear 35 and the connection shaft 32 is reduced as much as possible. A coil spring 39 serving as an urging member (torque applying means) for urging the two backlash gears 33 and 35 outward from each other on the outer periphery of the connection shaft 32 and between the first and second backlash gears 33 and 35. Is installed.

Next, a backlash removing mechanism using the two backlash gears 33 and 35 will be described in more detail with reference to FIGS. A second backlash gear 35 is fixed to a connection shaft 32 formed integrally with the first backlash gear 33. Therefore, the two backlash gears 33 and 35 are gears that rotate relatively in opposite directions. As shown in FIGS. 1 and 2, the first backlash gear 33 is urged rearward by a coil spring 39.
Since the thread groove 32a of the connection shaft 32 is a right-hand thread, the first backlash gear 33 is always applied with a clockwise torque as viewed from the front in the biased state. Then, as shown in FIG. 2, the teeth 34 of the first backlash gear 33 are shifted to the first gear 1 at the lower pitch point 34a.
The third tooth 25 is in contact with the upper pitch point 25a of the third tooth 25 in a pressed state. Therefore, the backlash between the first backlash gear 33 and the first gear 13 is eliminated.

On the other hand, as shown in FIGS. 1 and 3, the second backlash gear 35 is urged forward by a coil spring 39. Since the second backlash gear 35 rotates in the opposite direction to the first backlash gear 33,
In the biased state, a counterclockwise torque is always applied when viewed from the front. The pitch point 3 on the lower side of the tooth 2 8 pitch point 37a and the second gear 15 of the upper teeth 37 of the second backlash gear 35 as shown in FIG. 3
8a in a pressed state. Therefore, the backlash between the second backlash gear 35 and the second gear 15 is eliminated.

As shown in FIGS. 1 and 4, the first gear 1 to which the torque from the first backlash gear 33 is transmitted.
No. 3 generates a counterclockwise torque. In this state, the teeth 25 of the first gear 13 are at the upper pitch point 25a.
In contact with the first pitch point 2 6 a and the pressing state of the lower side of the teeth 2 6 transfer gear 24 at. Therefore, backlash between the first transmission gear 24 and the first gear 13 is eliminated.

On the other hand, as shown in FIG. 5, the second gear 15 to which the torque from the second backlash gear 35 is transmitted.
Indicates that clockwise torque is generated. And FIG.
Second gear 1 5 tooth 28 is in contact at the pitch point 29a and the pressing state of the upper teeth 29 of the second transmission gear 27 in the pitch point 28 a of the lower side as shown by. Therefore, backlash between the second transmission gear 27 and the second gear 15 is eliminated.

[0024] That is, the first backlash gear 33 torque of the first gear 13 based on the urging force of the coil spring 39, the first transmission gear 24, transmission shaft 23, the second transmission gear 2 7, the second The power is transmitted to the gear 15 and the second backlash gear 35, from the connecting shaft 32 to the first backlash gear 33, and the balance is maintained. When this torque is viewed from the second backlash gear 35, on the contrary, the second gear 15, the second transmission gear 27, the transmission shaft 23, the first transmission gear 24, the first gear 13, the first backlash gear 33 It can be thought that it is transmitted to. In any case, as a result, the torque of the two backlash gears 33 and 35 based on the coil spring 39 effectively eliminates the backlash between the respective gears.

Next, the operation of the speed reducer 1 of this embodiment will be described. As shown in FIG. 6, when the input shaft 2 rotates counterclockwise as viewed from the front after being driven by a motor (not shown), the drive is transmitted from the first gear 13 to the first transmission gear 24 first. Is done. The drive is further transmitted from the first transmission gear 24 to the transmission shaft 23, the second transmission gear 27, and the second gear 15, and the rotation is transmitted to the output shaft 3. Since the rotation of the first gear 13 as the small gear is converted into the rotation of the second gear 15 as the large gear, the output shaft 3 is rotated at a reduced speed.

On the other hand, the first backlash gear 33 is
As shown by the arrow, the torque rotating in the direction opposite to the rotation direction of the input shaft 2 acts, and the backlash with the first gear 13 is removed as described above. However, as a result, the first backlash gear 3
3, the driving force of the first gear 13 is directly transmitted to the first backlash gear 3 even if the input shaft 2 rotates.
3 is not transmitted. That is, it does not directly contribute to the drive transmission to the output shaft 3.

As shown by the arrow in FIG. 6, the drive of the input shaft 2 is first transmitted from the first gear 13 to the first transmission gear 24, and from the first transmission gear 24 to the transmission shaft 23 and the second transmission gear. Gear 27, second gear 15, second backlash gear 3
5, the first backlash gear 33 via the connecting shaft 32
Is transmitted to That is, the first backlash gear 33
At the same time as the first gear 13 starts to rotate,
The first gear 1 receives the driving force transmitted by bypass from the side.
It turns around together with 3. In this case, the first gear 13 rotates while maintaining the state in which the backlash between the first backlash gear 33 and the first gear 13 is removed.

Next, the operation when the motor (not shown) rotates in the reverse direction will be described. As shown in FIG. 7, the input shaft 2 rotates clockwise as viewed from the front, contrary to the case of FIG. Then, first, the drive is transmitted from the first gear 13 to the first backlash gear 33. The first further connecting shaft 32 from backlash gear 33, the second backlash gear 35, is driven to the second gear 15 is transmitted,
The rotation is reduced and transmitted to the output shaft 3.

On the other hand, as shown in FIG. 3, the first transmission gear 24 is acted upon by a torque that rotates in the direction opposite to the rotation direction of the input shaft 2, thereby eliminating the backlash with the first gear 13 as described above. Have been. However, since there is no contact with the first transmission gear 24 in the rotation direction of the first gear 13, even if the input shaft 2 rotates, the driving force of the first gear 13 is directly in the first direction. It is not transmitted to the transmission gear 24. That is, it does not directly contribute to the drive transmission to the output shaft 3.

As shown by the arrow in FIG. 7, the input shaft 2 is driven by the first gear 13 and the first backlash gear 3 first.
3, and then transmitted to the first transmission gear 24 via the connection shaft 32, the second backlash gear 35, the second gear 15, the second transmission gear 27, and the transmission shaft 23. That is, at the same time as the first gear 13 starts rotating, the first transmission gear 24 rotates together with the first gear 13 by receiving the driving force transmitted by bypassing from the connection shaft 32 side. Then, at that time, the first transmission gear 24 rotates while maintaining the state where the backlash between the first transmission gear 24 and the first gear 13 is removed.

As described above, the gear that directly receives the driving force from the first gear 13 by changing the rotation direction of the input shaft 2 becomes the first transmission gear 24 or the first backlash gear 33. Then, the backlash between the gears is maintained even if the input shaft 2 rotates in any direction.

With the above configuration, the first embodiment has the following effects. (1) Due to the urging force of the coil spring 39, the first backlash gear 33 and the second backlash gear 35 generate torques in directions opposite to each other. This torque causes a backlash between the first gear 13 and the first transmission gear 24,
The backlash between the second transmission gear 27 and the second gear 15, the backlash between the second gear 15 and the second backlash gear 35, and the backlash between the first backlash gear 33 and the first gear 13 are respectively removed. Is done. Therefore, there is no problem such as generation of abnormal noise when the gears mesh with each other, and even when a rotary encoder is mounted on the output shaft 3 or the like to detect the rotation amount, the shaft 3 always has no play. An accurate rotation amount can be measured.

(2) Even if the amount of backlash varies somewhat due to temperature differences, dry and wet conditions, and further wear of the gear teeth, the backlash is automatically adjusted by the buffering action of the coil spring 39. (3) Since the connecting shaft 32 and the second backlash gear 35 are ball screws, the second backlash gear 3
The friction when rotating 5 with respect to the connecting shaft 32 is small.
Accordingly, it is intended smaller as compared to not using the spring strength Gabo Lumpur screw coil spring 39 for generating a torque in the second backlash gear 35.

(4) When the input shaft 2 rotates counterclockwise when the input shaft 3 is viewed from the front, the first gear 13
The drive is transmitted to the transmission gear 24, and the drive is transmitted to the output shaft 3 from the transmission shaft 23 side. Conversely, when the input shaft 2 rotates clockwise, the drive is transmitted from the first gear 13 to the first backlash gear 33 and the connection shaft 3
Drive is transmitted from the second side to the output shaft 3. Regardless of the direction of rotation, the drive is transmitted to the output shaft 3 while maintaining the state in which the backlash between the gears is removed.

(5) A screw groove 32a is provided in front of the connecting shaft 32.
Is formed, and the second backlash gear 35 can move back and forth on the outer periphery of the thread groove 32 a of the connection shaft 32. Therefore, even if the distance between the input shaft 2 and the output shaft 3 is not strictly measured, fine adjustment can be made on site. In addition, when applied to other models having different distances between the input shaft 2 and the output shaft 3, the second backlash gear 35 can be used without separate design by moving the second backlash gear 35. (Embodiment 2) The reduction gear 1 of Embodiment 2 will be described with reference to FIGS. 4 and 5, and FIGS. Note that members and components common to those in the first embodiment have the same functions and effects, and thus are denoted by common reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 8, a bearing 30 is provided between the right bearing 12 (upper in FIG. 8) formed on the input shaft frame 4 and the same right bearing 18 formed on the output shaft frame 5. , 31 via which a connecting shaft 46 is rotatably mounted. A first backlash gear 47 made of a spur gear meshing with the first gear 13 is fixed near the rear end of the connecting shaft 46. A part of the teeth 25 of the first gear 13 and a part of the teeth 48 of the first backlash gear 47 are always in mesh with each other, and a backlash is formed between the two gears 13 and 47. The number of teeth and the module of the first backlash gear 47 are the same as those of the first transmission gear 24. As shown in FIG. 9A, a pair of long holes 47a are formed in a position penetrating from the front side to the rear side of the first backlash gear 47 at positions 180 degrees opposite to the outer periphery of the first backlash gear 47. Have been.

As shown in FIGS. 8 and 9A, a rotating disk 49 is mounted on the connecting shaft 46 on the front side of the first backlash gear 47, adjacent to the first backlash gear 47. Have been. The turntable 49 is a disk-shaped ring body having a through hole 49a formed at the center thereof, through which the connection shaft 46 is inserted, and rotatable with the connection shaft 46 inserted. On the outer peripheral edge of the turntable 49, concave portions 50 are formed at six locations at predetermined intervals as locking portions when a wrench (not shown) is mounted and rotated. 180 near the outer periphery of the turntable 49
The first backlash gear 47
A long hole 49b corresponding to the long hole 47a is formed.
Eight small holes 49c are formed at equal intervals on the inner peripheral side of the long hole 49b so as to surround the insertion hole 49a. Turntable 4
9 and both long holes 47a, 49 of the first backlash gear 47.
A fixing pin 51a serving as a spring member fixing means is inserted through b, and the turntable 49 and the first backlash gear 47 are integrally fixed by a fixing nut 51b. Turntable 4
9 and the first backlash gear 47 are formed into two long holes 47a, 4
9b is relatively rotatable in the overlapping range.

As shown in FIG. 8 and FIG.
A second backlash gear 52 composed of a spur gear meshing with the second gear 15 is fixed to the tip of the second backlash gear 52.
The second backlash gear 52 has the same number of teeth and modules as the second transmission gear 27. Part of the teeth 53 of the second backlash gear 52 and the teeth 38 of the second gear 15
Are always in mesh with each other, and both gears 15, 5
A backlash is formed between the two. As shown in FIG. 10, the small hole 4 of the first backlash gear 47 is formed on the rear surface of the second backlash gear 52 along the circumferential direction.
Eight small holes 52a corresponding to 9c are formed. A spring member (torque applying means) is provided in both small holes 49c and 52a.
Both ends of a spring shaft 54 having a circular cross section made of two hard steel wires are inserted and held in a suspended state. The diameter of the spring shaft 54 is 6 mm.

Next, FIGS. 4 and 5 through 11 and 12 will be described.
The backlash removing mechanism using the two backlash gears 47 and 52 will be described in more detail based on FIG. First, 1
The spring shaft 54 is suspended between the small holes 49c and 52a. The other spring shaft 54 is 18
It is also suspended between opposing small holes at a position opposing 0 degrees.
In this state, a rotational force based on the torque of the spring shaft 54 has not yet been generated between the two backlash gears 47 and 52. Further, the rotating disk 49 is not fixed to the first backlash gear 47. In this state, the long hole 47
The fixing pins 51a are temporarily inserted into the holes 49a and 49b.
Next, the turntable 49 is rotated counterclockwise as viewed from the front, to apply a bending moment to both spring shafts 54 to generate clockwise torque. As shown in FIG. 11, in a state where torque is applied to the rotating disk 49 in a clockwise direction as viewed from the front, the fixing nut 51b at the tip of the fixing pin 51a is tightened, and the rotating disk 49 is moved to the first backlash gear 4
7 is fixed. Then, a clockwise torque is always applied to the first backlash gear 47.

As shown in FIG. 11, the teeth 48 of the first backlash gear 47 are in press contact with the upper pitch points 25a of the teeth 25 of the first gear 13 at the lower pitch points 48a. Therefore, the first backlash gear 4
The backlash between 7 and the first gear 13 has been eliminated.

On the other hand, as shown in FIG. 12, the torque of the two back shafts 52 is applied to the second backlash gear 52 in a direction relatively opposite to that of the first backlash gear 47. The pitch point 53a of the upper teeth 53 of the second backlash gear 52 as shown in FIG. 12 is in contact at the pitch point 2 8a and the pressing state of the lower side of the tooth 2 8 of the second gear 15. Therefore, the backlash between the second backlash gear 52 and the second gear 15 is eliminated.

As described in the first embodiment with reference to FIGS. 4 and 5, the first backlash gear is also used in the second embodiment.
The first gear 13 to which the torque from 47 is transmitted generates a counterclockwise torque. In this state, the teeth 25 of the first gear 13 are pressed against the lower pitch points 25a of the teeth 25 of the first transmission gear 24 at the upper pitch points 25a, and the backlash is removed. Further, as in the first embodiment, the backlash between the second transmission gear 27 and the second gear 15 is removed.

That is, the rotational force of the first backlash gear 47 based on the torque of both spring shafts 54 is applied to the first gear 13, the first transmission gear 24, the transmission shaft 23, and the second
Transmission gear 2 7, the second gear 15, the balance and round is maintained from the second are transmitted to the backlash gear 52 connecting shaft 46 to the first backlash gear 47. On the other hand, when viewed from the second backlash gear 52, the rotational force is opposite to the second gear 15, the second transmission gear 27, and the transmission shaft 2
3, the first transmission gear 24, the first gear 13, and the first backlash gear 52 can be considered as being transmitted. In any case, as a result, the torque based on both spring shafts 54 effectively eliminates backlash between the respective gears.

Next, the operation of the speed reducer 1 according to the second embodiment will be described. Since the operation of the second embodiment is basically the same as that of the first embodiment, the description will be simplified. As shown in FIG. 13, when the input shaft 2 rotates counterclockwise when viewed from the front after being driven by a motor (not shown), the first gear 13, the first transmission gear 24, the transmission shaft 23, The second transmission gear 27, the second
The drive is transmitted to the gear 15 and the rotation is transmitted to the output shaft 3. Since the rotation of the first gear 13 as the small gear is converted into the rotation of the second gear 15 as the large gear, the output shaft 3 is rotated at a reduced speed.

On the other hand, the first backlash gear 47 is
As indicated by 1, a torque rotating in a direction opposite to the rotation direction of the input shaft 2 acts, so that the torque of the input shaft 2 is not directly transmitted to the first backlash gear 47 . FIG.
As shown by the arrow 3, the drive of the input shaft 2 is performed by the first gear 1.
3, the first transmission gear 24, the transmission shaft 23, the second transmission gear 27, the second gear 15, the second backlash gear 52,
It is transmitted to the first backlash gear 47 bypassing the connection shaft 46.

Next, the operation when the motor (not shown) rotates in the reverse direction will be described. As shown in FIG.
Rotates clockwise as viewed from the front, contrary to the case of FIG. The driving force is transmitted to the first gear 13, the first backlash gear 47, the connecting shaft 46, the second backlash gear 52 , and the second gear 15, and the rotation is reduced to the output shaft 3. Is communicated.

On the other hand, a torque is applied to the first transmission gear 24 in a direction opposite to the rotation direction of the input shaft 2. Therefore, even if the input shaft 2 rotates, the driving force of the first gear 13 is directly. Is not transmitted to the first transmission gear 24.

As shown by the arrows in FIG. 14, the input shaft 2 is driven by the first gear 13, the first backlash gear 47, the connecting shaft 46, the second backlash gear 52, and the second gear 1
5. The power is transmitted to the first transmission gear 24 bypassing the second transmission gear 27 and the transmission shaft 23.

With the above configuration, the second embodiment has the following effects. (1) The torque of both spring shafts 54 causes the first
Backlash gear 47 and second backlash gear 52
Are applied with rotational forces in directions opposite to each other. This torque causes the backlash between the first gear 13 and the first transmission gear 24, the backlash between the second transmission gear 27 and the second gear 15, and the second gear 15 and the second backlash gear 52.
And the backlash between the first backlash gear 47 and the first gear 13 are removed.
Therefore, there is no problem such as generation of abnormal noise when the gears mesh with each other, and even when a rotary encoder is mounted on the output shaft 3 or the like and the amount of rotation is detected, the shaft 3 always has no play and is accurate. The amount of rotation can be measured.

(2) Even if there is a slight variation in the backlash amount due to a temperature difference, dry and wet, and further, abrasion of the gear teeth, the backlash is automatically adjusted by the buffering action of the two spring shafts 54. (3) If the relative amount of rotation between the first backlash gear 47 and the turntable 49 is changed and fixed, the spring shaft 54
Can be increased or decreased. That is, as the amount of torsion is increased, the torque is increased accordingly, and a strong relative rotational force is generated between the first backlash gear 47 and the second backlash gear 52, so that the backlash of each gear can be reliably removed. Can be.

(4) Two spring shafts 54 are disposed between the rotating disk 49 and the second backlash gear 52 at positions opposed to each other by 180 degrees. Therefore, the backlash gears 47 and 52 can be relatively rotated in a well-balanced manner.

(5) After setting all the gears, the turntable 49 is rotated to fix the fixing pin 51a and the nut 5
The backlash can be easily removed simply by fixing with 1b. Also, when rotating the turntable 49, a large force is not required by mounting a wrench corresponding to the concave portion 50.
The number of the concave portions 50 may be less than six, one or more, or seven or more.

In addition, the effect of (4) of the first embodiment is similarly obtained in the second embodiment. As mentioned above, although the Example of this invention was described in full detail, this invention can be changed and implemented in another aspect.

In the first and second embodiments, the present invention is applied to the speed reducer 1, but it may be applied to a speed increaser. This is because, even in this case, the problem of backlash removal of the drive transmission by the gear occurs.

The number of gear teeth and the number of modules other than those in the above embodiment can be freely set. In the first embodiment, the coil spring 39 is used as the torque applying means.
It is also possible to use a plate spling 55 as shown in FIG. Even in this case, both backlash gears 33, 3
This is because relative torque is generated in 5.

In the second embodiment, the spring shaft 54 made of a hard steel wire is used. However, a piano wire, an oil-tempered wire, a carbon tool steel, a manganese steel, a silicon-manganese steel, a silicon-chromium steel, a manganese-chromium steel are also used. , A chromium-vanadium steel, a manganese-chromium-vanadium steel, a boron-added steel, a nickel-chromium-molybdenum steel, or another spring steel may be used. Also, thin wires may be used in a bundle, and these wires may be used in combination.

In the second embodiment, two spring shafts 54 are used. However, since eight small holes 49c and 52a are formed, up to eight spring shafts 54 can be mounted. Therefore, the torque can be easily adjusted by changing the number of spring shafts 54 to be mounted. When obtaining the same torque, spring shafts 54 having different diameters may be used. For example, in the second embodiment, the diameter of the spring shaft 54 is 6 m.
m, but the diameter may be 3 mm when both of the eight small holes 49c and 52a are used. Therefore, it is also possible to use a combination of spring shafts 54 of various diameters to obtain a desired torque.

In the second embodiment, the spring shaft 54 is mounted in the small holes 49c and 52a facing each other in principle. However, they may be attached to the small holes 49c and 52a other than the opposing position. Further, the number of the small holes 49c and 52a is not necessarily limited to eight, and may be seven or less or nine or more. The small holes 49c and 52a are preferably at equal intervals because the spring shafts 54 can be mounted in a well-balanced manner, but are not necessarily equal.

The concave portion 50 serving as a wrench mounting portion for rotating the turntable 49 may use other means. For example, an insertion hole may be formed in the outer periphery of the rotating disk 49, and a long member such as a bur may be inserted into the insertion hole and rotated.
Also, it is not always necessary.

In addition, the present invention may be variously modified as a gear transmission, for example, having a planetary gear mechanism, provided that a torque applying means for applying a reverse torque to the backlash gear is interposed. The present invention can be freely changed and implemented without departing from the gist of the invention, such as application.

Additional Notes Other technical ideas grasped by the above embodiments will be described below together with their effects.

(1) As a bending moment applying means according to claim 3, one end of a spring member is fixed to a rotating disk rotatable coaxially with the backlash gear, and the rotating disk is relatively rotated between the rotating member and the backlash gear. To give bending moment to members. Thus, backlash can be easily removed by rotating the turntable after all the gears are combined.

(2) In (1), as a spring member fixing means, a long hole is formed in the rotating disk and the backlash gear 47, and a fixing member is attached to and fixed to both the long holes. This makes it possible to adjust the torque of the spring member by changing the fixed position with the elongated hole.

[0064]

As described in detail above, in the invention of each claim, since torque is applied to both backlash gears in opposite directions, the backlash of each gear is consequently reduced due to, for example, temperature, humidity, wear and the like. Will be removed even if the condition is changed. Further, the biasing force of the biasing member is converted into a torque for rotating the both backlash gear relatively opposite directions by the screw, backlash of the gears are divided. In particular, in the invention of claim 3, in a state of bending by the bending moment application means a place ne member, the torque constantly both backlash gear for fixed occurs, the backlash in the same manner as the invention of claim 2 is removed You.

[Brief description of the drawings]

FIG. 1 is a plan sectional view illustrating a transmission according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the transmission according to the first embodiment, taken along line AA.

FIG. 3 is a main part cross-sectional view of the transmission according to the first embodiment, taken along line BB.

FIG. 4 is a cross-sectional view of a main part of the transmission according to the first embodiment and a second embodiment, taken along line CC.

FIG. 5 is a cross-sectional view of a main part of the transmission according to the first and second embodiments, taken along line DD.

FIG. 6 is a main part plan view for explaining a transmission direction of drive of the transmission in the same first embodiment.

FIG. 7 is a main part plan view for explaining a transmission direction of drive of the transmission in the same first embodiment.

FIG. 8 is a plan sectional view illustrating a transmission according to a second embodiment of the present invention.

FIGS. 9A and 9B are perspective views of a first backlash gear according to the second embodiment, in which FIG. 9A is a perspective view as viewed obliquely from the rear and FIG. 9B is a perspective view as viewed obliquely from the front.

FIG. 10 is a perspective view of a second backlash gear according to the second embodiment.

FIG. 11 is a cross-sectional view of a main part of the transmission according to the second embodiment, taken along line EE.

FIG. 12 is a cross-sectional view of a main part of the transmission according to the second embodiment, taken along line FF.

FIG. 13 is a main part plan view for explaining a transmission direction of drive of the transmission in the same second embodiment.

FIG. 14 is a main part plan view for explaining a transmission direction of drive of a transmission in the same second embodiment.

FIG. 15 is a plan view illustrating a main part of another embodiment.

FIG. 16 is a partially cutaway plan view illustrating a conventional gear transmission.

FIG. 17 is a cross-sectional view of a main part of the same conventional example as viewed from line MM.

FIG. 18 is a cross-sectional view of a main part of the same conventional example as viewed from the line NN.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reduction gear which is a transmission, 2 ... Input shaft, 3 ... Output shaft, 24
... first transmission gear, 27 ... second transmission gear, 33 ... first
Backlash gear, 35... Second backlash gear,
32 ... connecting shaft as a screw member (torque applying means), 39 ...
Coil spring as urging member (torque applying means), 4
9: rotating disk serving as bending moment applying means (torque applying means); 54: spring shaft serving as a spring member (torque applying means); 51a: spring fixing means (torque applying means)
Barrel fixing pin, 51b A fixing nut serving as a spring fixing means (torque applying means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 57/12 F16H 1/22 F16H 55/18

Claims (3)

(57) [Claims] 1. A first transmission gear is fixed to an input shaft, a first transmission gear meshing with the first transmission gear is mounted on a transmission shaft side, and a second transmission gear is mounted on the transmission shaft side. Wear it,
A first backlash gear meshing with a first gear in a gear transmission configured to mesh with a second gear fixed to an output shaft so as to shift the rotation of the input shaft to the output shaft and transmit the rotation. When the torque applying means for applying a relatively opposite direction of the torque is interposed for both backlash gears between the second backlash gear that second gear engaged, the torque applying means, said one of backlash Gears
It is fixed coaxially with the rotation axis and the other
The screw member meshing with the gear and the backlash gear
A backlash removing device for a gear transmission, comprising a biasing member for biasing the gear transmission in the opposite direction . 2. The backlash tooth according to claim 2, wherein the biasing member includes the backlash teeth.
The backlash removing device for a gear transmission according to claim 1, wherein the device is constituted by a spring member suspended between the vehicles . Wherein the torque applying means includes a bending moment applying means for applying a bending moment to said spring member,
The backlash removing device for a gear transmission according to claim 2 , further comprising a spring member fixing means for fixing the spring member in a state where a bending moment is applied.