JP2020183804A - Gear mechanism, reduction gear and driving device using the reduction gear - Google Patents

Abstract

To provide a reduction gear which can change a transmission gear ratio of an input gear and an output gear without requiring a large-scaled component replacement, and which can suppress a sharp rise in component cost, and to provide a driving device using the reduction gear.SOLUTION: A reduction gear includes a support block, an input gear 33, an intermediate gear 32, an output gear and a gear position change mechanism. The input gear is rotatably supported by the support block. The intermediate gear meshes with the input gear. The output gear meshes with the intermediate gear. The gear position change mechanism can change the position of the intermediate gear 32 with respect to the input gear 33 and the output gear.SELECTED DRAWING: Figure 5

Description

The present invention relates to a gear mechanism, a speed reducer, and a drive device using the speed reducer.

In industrial robots, machine tools, etc., a speed reducer is used to reduce the rotation of a rotation drive source such as a motor. In the speed reducer, an intermediate gear that meshes with both gears may be interposed between the input gear and the output gear (see, for example, Patent Document 1).

In this type of reduction gear, the input gear and the output gear are rotatably supported by a support block such as an output rotating body or a casing. Similarly, the intermediate gear is rotatably supported by a support block such as an output rotating body or a casing, and meshes with the input gear and the output gear. The rotation of the input gear is reduced to a speed ratio corresponding to the gear ratio of the output gear and the input gear and transmitted to the output gear. The support shaft of the intermediate gear is fixed to the holding hole of the support block at a position where the tooth surface of the intermediate gear meshes with both tooth surfaces of the input gear and the output gear.

Japanese Patent No. 5231530

In this type of reduction gear, the input gear may be replaced with another input gear having a different number of teeth for the purpose of changing the reduction ratio or the like. In this case, if a new input gear is attached to the output shaft of the drive source, the distance between the input gear and the tooth surface of the output gear changes. Therefore, in order to engage the tooth surface of the intermediate gear with the tooth surface of the new input gear, the position of the support shaft of the intermediate gear must be changed. In this case, it is necessary to replace the support block such as the output rotating body or the casing to which the support shaft of the intermediate gear is fixed with another one having a different holding hole position. Further, when replacing the output gear with one having a different number of teeth, it is necessary to replace the support block for the same reason.
Therefore, in the conventional speed reducer, when the input gear or the output gear is replaced with one having a different number of teeth, a large-scale replacement of parts is required, and the cost of parts rises.

The present invention is a speed reducer capable of changing the gear ratio of an input gear and an output gear without requiring a large-scale replacement of parts, and can suppress an increase in parts cost, and a drive device using the speed reducer. I will provide a.
The present invention further uses a gear mechanism, a speed reducer, and a speed reducer thereof that can expand the range of change of the gear ratio without requiring a large-scale replacement of parts and suppress a rise in parts cost. Provide a drive unit.

The speed reducer of one aspect of the present invention includes a support block, an input gear rotatably supported by the support block, an intermediate gear that meshes with the input gear, an output gear that meshes with the intermediate gear, and the input gear. A gear position changing mechanism capable of changing the position of the intermediate gear with respect to the output gear is provided.

With the above configuration, when at least one of the input gear and the output gear is replaced, the position of the intermediate gear is changed by the gear position changing mechanism according to the change in the distance between the tooth surfaces between the input gear and the output gear. To change. In this configuration, it is possible to change the reduction ratio of the input gear and the output gear without exchanging the support block. Therefore, it is possible to change the gear ratio of the input gear and the output gear without requiring a large-scale replacement of parts, and it is possible to suppress an increase in parts cost.

The gear position changing mechanism may hold the support shaft of the intermediate gear and may include a holding member that is detachably attached to the support block.

In this case, the position of the intermediate gear can be changed by changing the assembling direction of the holding member with respect to the support block or the holding member itself.

The holding member has a holding portion of the support shaft at a position separated from a reference position on the holding member, and the holding member and the support block rotate a rotation position of the holding member around the reference position. The gear position changing mechanism may have a changeable rotation position changing portion, and may have a configuration having the holding portion of the holding member and the rotation position changing portion.

When replacing at least one of the input gear and the output gear, the rotation position around the reference position of the holding member is changed by the rotation position change portion according to the change in the distance between the tooth surfaces between the input gear and the output gear. To change. As a result, the position of the support shaft of the intermediate gear in the state where the holding member is attached to the support block is changed. When this configuration is adopted, the position of the intermediate gear can be easily changed only by changing the rotation position of the holding member.

The holding member is formed in a columnar shape centered on the reference position, the support block has a circular holding hole into which the outer peripheral surface of the holding member is fitted, and the rotation position changing portion is , The outer peripheral surface of the holding member and the holding hole may be provided.

When replacing at least one of the input gear and the output gear, the rotation angle around the axis of the holding member is appropriately changed according to the change in the distance between the tooth surfaces between the input gear and the output gear. In this state, the holding member is fitted into the holding hole of the support block.

The support shaft may be integrally formed with the holding portion of the holding member.

In this case, since the support shaft of the intermediate gear is formed integrally with the holding member, the number of component parts can be reduced.

The speed reducer of one aspect of the present invention includes a support block, an input gear rotatably supported by the support block, an intermediate gear that meshes with the input gear, an output gear that meshes with the intermediate gear, and the intermediate gear. A holding member that holds the support shaft and is detachably attached to the support block is provided, and the holding member is formed in a columnar shape and is supported at a position separated from the axial position of the holding member. The shaft is integrally formed, the support block has a circular holding hole into which the outer peripheral surface of the holding member is fitted, and the outer peripheral surface of the holding member and the holding hole of the support block are the same. A rotation position changing portion capable of changing the rotation position around the axis of the holding member is configured.

With the above configuration, when at least one of the input gear and the output gear is replaced, the rotational position of the holding member is appropriately changed according to the change in the distance between the tooth surfaces between the input gear and the output gear. The outer peripheral surface of the holding member is fitted into the holding hole of the support block. As a result, the position of the intermediate gear on the support block is changed. In this configuration, it is possible to change the reduction ratio of the input gear and the output gear only by changing the rotation position of the holding member with respect to the holding hole of the support block. Therefore, it is possible to change the gear ratio of the input gear and the output gear without requiring a large-scale replacement of parts, and it is possible to suppress an increase in parts cost.

The speed reducer of one aspect of the present invention includes a support block, an input gear rotatably supported by the support block, an intermediate gear that meshes with the input gear, an output gear that meshes with the intermediate gear, and the intermediate gear. It is provided with a shaft position changing portion that can change the position of the support shaft.

When replacing at least one of the input gear and the output gear, the position of the support shaft of the intermediate gear is changed by the shaft position change portion according to the change in the distance between the tooth surfaces between the input gear and the output gear. To do. In this configuration, it is possible to change the reduction ratio of the input gear and the output gear without exchanging the support block.

The support block may have a plurality of support shaft fitting holes into which the support shaft can be fitted, and the shaft position changing portion may be composed of the plurality of support shaft fitting holes.

When replacing at least one of the input gear and the output gear, the support shaft fitting hole on the support block is appropriately selected according to the change in the distance between the tooth surfaces between the input gear and the output gear. Fit the support shaft into the optimum support shaft fitting hole.

The drive device of one aspect of the present invention is a drive device including a speed reducer that decelerates and outputs the rotation of a rotation drive source and a rotation block connected to an output unit of the speed reducer, and the speed reduction is provided. The machine includes a support block, an input gear rotatably supported by the support block, an intermediate gear that meshes with the input gear, an output gear that meshes with the intermediate gear, and the intermediate gear for the input gear and the output gear. It is equipped with a gear position change mechanism that can change the position of.

The gear mechanism of one aspect of the present invention is
Support block and
The first gear rotatably supported by the support block,
The second gear that meshes with the first gear,
The third gear that meshes with the second gear,
A shaft position changing portion capable of changing the position of the support shaft of the second gear corresponding to the third gear having a different number of teeth,
To be equipped.

As a result, the position of the support shaft of the second gear is changed according to the third gear having a different number of teeth by the shaft position changing portion, so that the tooth surface between the third gear and the second gear is changed. The range of change in the gear ratio between the first gear and the third gear can be expanded according to the change in the distance without exchanging the support block.

In the present invention, the shaft position changing portion can have a plurality of support hole portions formed so as to be able to rotatably support the inserted support shaft and separated from the support block.

In the present invention, the support block may have a plurality of the support holes along the circumference at a predetermined distance from the rotation center of the first gear.

The present invention has a first base portion and a second base portion in which the support block is located on both sides of the second gear so as to face the axial direction of the second gear.
The support hole portion may be provided on at least one facing surface of the first base portion and the second base portion.

In the present invention, a plurality of the support holes are arranged along a circumference at a predetermined distance from the rotation center of the first gear, and the facing surface of the first base portion and the second base portion are arranged on the circumference. It is formed alternately with the facing surface of the above.

The speed reducer of one aspect of the present invention has a support block, a first gear rotatably supported by the support block, a second gear that meshes with the first gear, a third gear that meshes with the second gear, and a number of teeth. A gear mechanism including a shaft position changing portion capable of changing the position of the support shaft of the second gear corresponding to a different third gear.
A speed reducer connected to the gear mechanism and
To be equipped.

The circumference on which the plurality of support holes are arranged is centered on the rotation center of the first gear, and the radius of the circumference coincides with the distance from the rotation center of the first gear to the rotation center of the second gear. can do.

The speed reducer and drive device described above can change the gear ratio of the input gear and the output gear without requiring a large-scale replacement of parts. Therefore, when the above-mentioned speed reducer or drive device is adopted, it is possible to suppress an increase in component cost.
Further, the gear mechanism, the speed reducer, and the drive device described above can change the gear ratio and can expand the range of change of the gear ratio without requiring a large-scale replacement of parts. Therefore, when the above-mentioned gear mechanism, speed reducer, or drive device is adopted, it is possible to suppress an increase in component cost.

It is a perspective view of the drive device of 1st Embodiment. It is a front view of the speed reducer of 1st Embodiment. It is sectional drawing which follows the line III-III of FIG. 2 of the speed reducer of 1st Embodiment. FIG. 5 is an enlarged cross-sectional view showing a part of FIG. 3 of the speed reducer of the first embodiment. It is sectional drawing substantially along the VV line of FIG. 3 of the speed reducer of 1st Embodiment. It is sectional drawing substantially along the VV line of FIG. 3 of the speed reducer of 1st Embodiment. It is sectional drawing corresponding to a part of FIG. 5 of the reduction gear of 2nd Embodiment. It is sectional drawing corresponding to a part of FIG. 6 of the reduction gear of 2nd Embodiment. It is an end view of the inside of the reduction gear of the third embodiment. It is sectional drawing of the gear mechanism and reduction gear of 4th Embodiment. FIG. 5 is a cross-sectional view taken along the line XI-XI of FIG. 10 of the gear mechanism and speed reducer of the fourth embodiment. It is explanatory drawing of the shaft position change part of 4th Embodiment. It is sectional drawing which follows the XIII-XIII line of FIG. 12 of the gear mechanism and reduction gear of 4th Embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings. In each of the embodiments described below, the same reference numerals will be given to the common parts, and some duplicate explanations will be omitted.

(First Embodiment)
First, the first embodiment shown in FIGS. 1 to 6 will be described.
FIG. 1 is a perspective view of a drive device 1 used when welding, assembling parts, or the like.
The drive device 1 includes a base block 11 installed on the floor surface F, a speed reducer 10 fixedly installed on the upper surface of the base block 11 on one end side in the longitudinal direction, and a rotary drive source that outputs power to the speed reducer 10. The motor 2, the holding device 12 fixedly installed on the upper surface of the base block 11 on the other end side in the longitudinal direction, and the rotating block 13 in which both ends in the longitudinal direction are supported by the speed reducer 10 and the holding device 12. , Is equipped. The motor 2 is integrally attached to the input side of the speed reducer 10. The speed reducer 10 decelerates the rotation of the motor 2 and transmits the rotation to one end side of the rotation block 13 in the longitudinal direction. The holding device 12 rotatably supports the other end side of the rotating block 13 in the longitudinal direction. The rotation block 13 rotates about the axis o1 substantially along the horizontal direction by transmitting power from the motor 2 via the speed reducer 10.

In the case of the present embodiment, the rotating block 13 has a plurality of work support surfaces 13a around the axis o1. A work w, which is a work target, is attached to each work support surface 13a. The work w attached to the work support surface 13a is moved toward the work position by the rotation of the rotation block 13 by the motor 2. At the working position, for example, a working device 3 such as a welding robot is installed.

FIG. 2 is a front view of the speed reducer 10 as viewed from the output side (the side to which the rotating block 13 is attached), and FIG. 3 is a cross-sectional view taken along the line III-III of FIG. Further, FIG. 4 is a cross-sectional view of the speed reducer 10 in which a part of FIG. 3 is enlarged, and FIG. 5 is a cross-sectional view of the speed reducer 10 substantially along the VV line of FIG. In FIG. 5, the central gear 30, the crankshaft gear 31, the intermediate gear 32, and the like, which will be described later, are not cross-sectioned. Further, in FIG. 5, a holding member 40 and a mounting base 38, which will be described later, are also shown.
The speed reducer 10 has a fixed block 14 whose lower end is fixedly installed on the upper surface on one end side of the base block 11 (see FIG. 1), and a first carrier block 15A and a second carrier block 15B integrally coupled to the fixed block 14. An outer cylinder 17 rotatably supported on the outer peripheral side of the first carrier block 15A and the second carrier block 15B via a bearing 16, and rotatably supported by the first carrier block 15A and the second carrier block 15B. A plurality (three) crankshafts 18 and a first swivel gear 19A and a second swivel gear 19B that swivel together with two eccentric portions 18a and 18b of each crankshaft 18 are provided. The speed reducer 10 is installed in the base block 11 so that the rotation center axis c1 of the output unit coincides with the axis o1 of the drive device 1.

The fixing block 14 includes a perforated disc-shaped base flange 14a (see FIG. 3) having a circular through hole 25 in the center, and a leg portion 14b (see FIG. 2) extending downward from the base flange 14a. Have. In the fixing block 14, the lower end of the leg portion 14b is fixed to the base block 11 by bolting or the like. A perforated disk-shaped first carrier block 15A is superposed on one end surface of the base flange 14a in the thickness direction, and the first carrier block 15A is integrally fixed by bolting or the like. Further, the second carrier block 15B is fixed to the end surface of the first carrier block 15A on the opposite side of the base flange 14a by bolting or the like. The second carrier block 15B has a perforated disk-shaped substrate portion 15Ba and a plurality of support columns (not shown) extending from an end surface of the substrate portion 15Ba toward the first carrier block 15A. In the second carrier block 15B, the end face of the strut portion is abutted against the end face of the first carrier block 15A, and each strut portion is fixed to the first carrier block 15A. An axial gap is secured between the first carrier block 15A and the substrate portion 15Ba of the second carrier block 15B. A first swivel gear 19A and a second swivel gear 19B are arranged in this gap.
The first swivel gear 19A and the second swivel gear 19B are formed with escape holes (not shown) through which each strut portion of the second carrier block 15B penetrates. The relief hole is formed with an inner diameter sufficiently larger than that of the strut portion so that each strut portion does not interfere with the swivel operation of the first swivel gear 19A and the second swivel gear 19B.

The outer cylinder 17 is arranged so as to straddle the outer peripheral surface of the first carrier block 15A and the outer peripheral surface of the substrate portion 15Ba of the second carrier block 15B. Both ends of the outer cylinder 17 in the axial direction are rotatably supported by the first carrier block 15A and the substrate portion 15Ba of the second carrier block 15B via bearings 16. Further, on the inner peripheral surface of the central region of the outer cylinder 17 in the axial direction (the region facing the outer peripheral surfaces of the first swivel gear 19A and the second swivel gear 19B), a plurality of pin grooves extending in parallel with the rotation center axis c1 (Not shown) is formed. A substantially columnar internal tooth pin 20 is rotatably housed in each pin groove. A plurality of internal tooth pins 20 attached to the inner peripheral surface of the outer cylinder 17 face each outer peripheral surface of the first swivel gear 19A and the second swivel gear 19B.

The first swivel gear 19A and the second swivel gear 19B are formed to have an outer diameter slightly smaller than the inner diameter of the outer cylinder 17. External teeth 19Aa and 19Ba that are in mesh with a plurality of internal tooth pins 20 arranged on the inner peripheral surface of the outer cylinder 17 are formed on the outer peripheral surfaces of the first swivel gear 19A and the second swivel gear 19B. There is. The number of external teeth 19Aa and 19Ba formed on the outer peripheral surfaces of the first swivel gear 19A and the second swivel gear 19B is set to be slightly smaller (for example, one less) than the number of internal tooth pins 20. There is.

The plurality of crankshafts 18 are arranged on the same circumference centered on the rotation center axis c1 of the first carrier block 15A and the second carrier block 15B. Each crankshaft 18 is rotatably supported by a first carrier block 15A and a second carrier block 15B via a bearing 22. The eccentric portions 18a and 18b of each crankshaft 18 penetrate the first swivel gear 19A and the second swivel gear 19B, respectively. The eccentric portions 18a and 18b are rotatably engaged with the support holes 21 formed in the first swing gear 19A and the second swing gear 19B via the eccentric bearing 23. The two eccentric portions 18a and 18b of each crankshaft 18 are eccentric so that their phases are 180 ° out of phase with respect to the axis of the crankshaft 18.

When a plurality of crankshafts 18 receive an external force and rotate in one direction, the eccentric portions 18a and 18b of the crankshafts 18 turn in the same direction with a predetermined radius, and accordingly, the first turning gear 19A and the second turning gear 19B Turns in the same direction with the same radius. At this time, the outer teeth 19Aa and 19Ba of the first swivel gear 19A and the second swivel gear 19B come into contact with the plurality of internal tooth pins 20 held on the inner circumference of the outer cylinder 17 so as to mesh with each other.
In the speed reducer 10 of the present embodiment, the number of internal tooth pins 20 on the outer cylinder 17 side is set to be slightly larger than the number of teeth of the outer teeth 19Aa and 19Ba of the first swivel gear 19A and the second swivel gear 19B. Therefore, while the first turning gear 19A and the second turning gear 19B make one turn, the outer cylinder 17 is pushed around in the same direction as the turning direction by a predetermined pitch. As a result, the rotation of the crankshaft 18 is greatly decelerated and output as the rotation of the outer cylinder 17. In the present embodiment, since the eccentric portion 18a and the eccentric portion 18b of each crankshaft 18 are eccentric so as to deviate by 180 ° around the axis, the turning phases of the first turning gear 19A and the second turning gear 19B are different. It will be shifted by 180 °.

A perforated disk-shaped output plate 26 is attached to an axial end of the outer cylinder 17 opposite to the base flange 14a. The output plate 26 covers the end portion of the second carrier block 15B in a non-contact state, and a rotating block 13 (see FIG. 1) for holding the work can be attached to the end face on the outer side in the axial direction by bolting or the like. There is. Further, the inner peripheral portion of the output plate 26 penetrates the inner peripheral portions of the second carrier block 15B, the second swivel gear 19B, the first swivel gear 19A, the first carrier block 15A, and the base flange 14a in a non-contact state. A tubular portion 27 is attached. The tubular portion 27 rotates integrally with the output plate 26.

Further, the speed reducer 10 includes an input gear 33 connected to a rotating shaft (not shown) of the motor 2, and a central gear 30 (output gear) rotatably held on the inner peripheral surfaces of the base flange 14a and the first carrier block 15A. And an intermediate gear 32 that meshes with the input gear 33 and the center gear 30 and transmits the rotation of the input gear 33 to the center gear 30. The central gear 30 has a larger diameter than the input gear 33 and has a larger number of teeth than the input gear. Therefore, the rotation of the input gear 33 by the motor 2 is decelerated to a predetermined reduction ratio and transmitted to the central gear 30 in that state.

The input gear 33 is rotatably supported via a bearing 34 at an edge portion radially outwardly separated from the through hole 25 of the base flange 14a. The rotation center axis c4 of the input gear 33 is set parallel to the rotation center axis c1 on the output side of the speed reducer 10.

The center gear 30 is formed to have an axial length straddling the base flange 14a and the first carrier block 15A. External teeth 30a are formed in the central region of the central gear 30 in the axial direction. One end side of the central gear 30 in the axial direction is rotatably held on the inner peripheral surface of the through hole 25 of the base flange 14a via a bearing 35A. The other end side of the central gear 30 in the axial direction is rotatably held on the inner peripheral surface of the first carrier block 15A via the bearing 35B. The central gear 30 rotates about the rotation center axis c1.

Further, at the end of the first carrier block 15A on the base flange 14a side, a plurality (three) recesses 28 are formed corresponding to the positions of the plurality (three) crankshafts 18 described above. Each recess 28 is open to the inner peripheral surface side of the first carrier block 15A. Further, a crankshaft gear 31 for transmitting rotation to the crankshaft 18 is attached to the end of each crankshaft 18 on the base flange 14a side. The crankshaft gear 31 attached to each crankshaft 18 is arranged inside the corresponding recess 28. Each crankshaft gear 31 has external teeth 31a. The outer teeth 31a of each crankshaft gear 31 mesh with the axially opposite end region of the outer teeth 30a of the central gear 30. Therefore, the rotation input from the input gear 33 to the central gear 30 via the intermediate gear 32 is transmitted to each crankshaft 18 through the crankshaft gear 31.
In the reduction gear 10 of the present embodiment, the reduction gear in the front stage by the input gear 33 and the center gear 30, the reduction gear in the rear stage by the crankshaft 18, the first and second turning gears 19A and 19B, the outer cylinder 17, etc. Will slow down.

Further, a recessed portion 36 for accommodating the external teeth 33a portion of the input gear 33 and the intermediate gear 32 is formed at the end portion of the base flange 14a near the first carrier block 15A. A mounting base 38 for supporting the intermediate gear 32 is mounted on the bottom surface of the recessed portion 36 of the base flange 14a (the surface facing the end face of the first carrier block 15A). Further, a part of the recessed portion 36 is open to the through hole 25 in the center of the base flange 14a. The intermediate gear 32 arranged in the recessed portion 36 meshes with the external teeth 30a of the central gear 30 through the radially inner opening portion of the recessed portion 36.

The intermediate gear 32 is rotatably supported by a columnar support shaft 39. The support shaft 39 is integrally formed with a columnar holding member 40 having a larger outer diameter than the support shaft 39 and a shorter shaft length. The support shaft 39 is integrally formed at a position deviated from the axis c2 of the holding member 40. That is, the support shaft 39 is arranged eccentrically (offset in the radial direction) with respect to the axial center c2 of the holding member 40. The axis c3 of the support shaft 39 is set parallel to the axis c2 of the holding member 40.
In the present embodiment, the position of the axis c2 is the reference position on the holding member 40, and the portion 40a connected to the support shaft 39 on the holding member 40 is the holding portion of the support shaft 39. The holding portion of the support shaft 39 is arranged at a position separated from the position of the axis c2 which is the reference position.

The mounting base 38 mounted inside the recessed portion 36 is formed with a circular holding hole 41 in which the outer peripheral surface of the holding member 40 is fitted and fixed. In the case of the present embodiment, the position of the support shaft 39 of the intermediate gear 32 on the base flange 14a (base block 11) is changed by changing the rotation position of the holding member 40 around the axis c2 with respect to the holding hole 41. Can be done. The position of the support shaft 39 of the intermediate gear 32 is changed, for example, when the number of teeth and the outer diameter of the input gear 33 are changed in order to change the reduction ratio of the speed reducer 10.
In the case of the present embodiment, the mounting base 38, together with the fixed block 14 and the first carrier block 15A, constitutes a support block that rotatably supports the input gear 33, the center gear 30 (output gear), and the intermediate gear 32, respectively. doing. Further, in the present embodiment, the holding hole 41 of the mounting base 38 and the outer peripheral surface of the holding member 40 fitted in the holding hole 41 form a rotation position changing portion.

When the number of teeth and the outer diameter of the input gear 33 are changed, the distance between the outer teeth 33a of the input gear 33 and the tooth surface of the outer teeth 30a of the center gear 30 (output gear) changes, so that the conventional support shaft 39 At the position, the intermediate gear 32 cannot be reliably meshed with the input gear 33 and the center gear 30. In this case, by appropriately changing the position of the support shaft 39, the intermediate gear 32 can be reliably meshed with the input gear 33 and the center gear 30.

FIG. 6 is a cross-sectional view similar to FIG. 5 of the speed reducer 10 when the input gear 33 is replaced with a gear having a smaller diameter.
In the example shown in FIG. 5, the axis c3 of the support shaft 39 of the intermediate gear 32 is largely separated from the straight line L1 connecting the input gear 33 (A) and the tooth surface of the central gear 30 at the shortest distance. At this time, the axis c3 of the support shaft 39 is eccentric to the side farthest from the straight line L1 with respect to the axis c2 of the holding member 40.
As in the example of FIG. 6, when the outer diameter of the input gear 33 (B) becomes smaller, the distance between the tooth surfaces of the input gear 33 (B) and the central gear 30 increases, and at the position of the support shaft 39 shown in FIG. , The intermediate gear 32 cannot be reliably meshed with the input gear 33 and the center gear 30. In this case, the holding member 40 is removed from the holding hole 41, and the holding member 40 is rotated by 180 ° around the axis c2 and fitted into the holding hole 41 again. As a result, the axial center c3 of the support shaft 39 is eccentric to the side closest to the straight line L1 connecting the input gear 33 (B) and the tooth surface of the central gear 30 with respect to the axial center c2 of the holding member 40. To do. As a result, the intermediate gear 32 can be reliably meshed with the input gear 33 and the center gear 30 (B).

In this embodiment, a holding portion (a portion 40a connected to the support shaft) arranged apart from the axis c2 (reference position) on the holding member, and a holding hole 41 and a holding member 40 which are rotation position changing portions. The outer peripheral surface of the gear constitutes a gear position changing mechanism (shaft position changing portion).

As described above, in the speed reducer 10 of the present embodiment, the holding member 40 that holds the support shaft 39 of the intermediate gear 32 and the mounting base 38 that is the support block can change the position of the intermediate gear 32. It constitutes a change mechanism. Therefore, when replacing the input gear 33 with another gear having a different number of teeth and outer diameter, the gear responds to a change in the distance between the tooth surfaces between the input gear 33 and the center gear 30 (output gear). The position of the intermediate gear 32 can be changed by the position changing mechanism. Therefore, it is possible to change the reduction ratio of the input gear 33 and the center gear 30 (output gear) without replacing the support block such as the fixed block 14. Therefore, when the speed reducer 10 of the present embodiment is adopted, the gear ratios of the input gear 33 and the center gear 30 (output gear) can be changed without requiring a large-scale replacement of parts, and the increase in parts cost can be suppressed. be able to.

Further, in the speed reducer 10 of the present embodiment, the holding portion of the support shaft 39 (the portion 40a connected to the support shaft 39) is arranged at a position separated from the reference position (axis center c2) on the holding member 40, and the holding member A rotation position changing portion (fitting structure of the holding member 40 and the holding hole 41) capable of changing the rotation position of the holding member 40 is provided between the 40 and the mounting base 38 which is a support block. Therefore, when the speed reducer 10 of the present embodiment is adopted, the position of the intermediate gear 32 can be easily changed only by changing the rotation position of the holding member 40.

In particular, in the case of the present embodiment, the holding member 40 is formed in a columnar shape, and the holding hole 41 into which the holding member 40 is fitted is formed in the mounting base 38 which is a support block. The rotation position changing portion is formed by the outer peripheral surface of the holding member 40 and the holding hole 41 of the mounting base 38. Therefore, when the holding member 40 is fitted into the holding hole 41, the position of the intermediate gear 32 can be easily changed only by changing the rotation angle of the holding member 40.
In the present embodiment, the holding member 40 is formed in a columnar shape, but the outer peripheral surface of the holding member 40 may have a shape other than a circle, for example, a polygonal shape such as a quadrangle.

Further, in the speed reducer 10 of the present embodiment, since the support shaft 39 of the intermediate gear 32 is integrally formed with the holding member 40, the number of component parts can be reduced and the cost can be reduced.
However, it is also possible to form the support shaft 39 as a separate part from the holding member 40 and fix the support shaft 39 to the holding member 40 by press fitting or the like.

(Modification example)
In the above embodiment, the holding member 40 is detachably attached to the holding hole 41 of the mounting base 38, and when the input gear 33 is replaced with one having a different outer diameter, the holding member 40 is rotated by 180 ° and held again. It is fixed in the hole 41 in a fitted state. On the other hand, the mounting base 38 shown in FIGS. 5 and 6 may be mounted in a state of being rotated 180 ° around the axis c3 with respect to the base flange 14a (support block). Specifically, for example, it can be realized by arranging the left and right fastening fixing portions 50 of the mounting base 38 in a symmetrical shape.
In this case, since the holding member 40 does not need to be removed from the mounting base 38, the mounting base 38 may have an integral structure with the holding member 40. In the case of this modification, the mounting base 38 is not a part of the support block, but a part of the holding member that holds the support shaft 39.

(Second Embodiment)
FIG. 7 is a cross-sectional view corresponding to a part of FIG. 5 of the speed reducer 110 of the second embodiment, and FIG. 8 is a cross-sectional view corresponding to a part of FIG. 6 of the speed reducer 110 of the second embodiment. is there.
The speed reducer 110 of the present embodiment differs from the first embodiment only in the structure of the fitting portion between the holding member 40A and the mounting base 38A. The holding member 40A is provided with a pair of chamfered portions 40Aa parallel to each other on a columnar outer peripheral surface. The pair of chamfered portions 40Aa are formed symmetrically with the axial center c3 of the holding member 40A interposed therebetween. The mounting base 38A is formed with a holding hole 41A having a shape that matches the outer peripheral shape of the holding member 40A. That is, the holding hole 41A of the mounting base 38A is provided with two planes 41Aa parallel to each other. The two planes Aa come into contact with the two chamfered portions 40Aa on the holding member 40A side when the holding member 40A is fitted into the holding hole 41A of the mounting base 38A. Therefore, the holding member 40A is fitted into the holding hole 41A only at two rotational positions offset by 180 ° around the axis c2.

In the speed reducer 110 of the present embodiment, the holding member 40A can be fitted into the holding hole 41A only at two rotation positions shifted by 180 ° around the axis c2, so that the holding member 40A has two rotation positions. It can be accurately positioned at the position. Therefore, the tooth surfaces of the intermediate gear 32 can be accurately meshed with the two types of input gears 33 having different numbers of teeth and outer diameters.

(Third Embodiment)
FIG. 9 is an end view of the inner end surface (the end surface on the side facing the first carrier block) of the base flange 14a (fixed block 14) of the speed reducer 210 of the third embodiment as viewed from the front. In FIG. 9, two types of input gears 33 (A) and 33 (B) having different outer diameters and numbers of teeth, an intermediate gear 32, and a center gear 30 (output gear) are shown by virtual lines.
In the speed reducer 210 of the present embodiment, a plurality of support shaft fitting holes 45A and 45B into which the support shaft 239 of the intermediate gear 32 can be fitted are formed on the inner end surface of the base flange 14a. The forming positions of the support shaft fitting holes 45A and 45B are set at positions where the tooth surfaces of the intermediate gear 32 supported by the support shaft 239 mesh with the input gear 33 and the center gear 30 to be used. In the example shown in FIG. 9, the support shaft fitting holes 45A and 45B are two, but may be three or more. Further, in the present embodiment, the holding member for holding the support shaft 239 is not provided, and the support shaft 239 is formed in a simple cylindrical shape.
In the case of this embodiment, the plurality of support shaft fitting holes 45A and 45B form a shaft position changing portion capable of changing the position of the support shaft 239 of the intermediate gear 32.

When one of the input gears 33 (A) having a large outer diameter is used, the support shaft fitting hole on the side away from the straight line L1 connecting the input gear 33 (A) and the tooth surface of the center gear 30 at the shortest distance. The support shaft 239 is fixed to 45A in a fitted state. When replacing the input gear 33 (A) with the other input gear 33 (B) having a smaller outer diameter from this state, after removing the support shaft 239 from the support shaft fitting hole 45A, the input gear 33 (B) The support shaft 239 is fixed in the fitted state in the support shaft fitting hole 45B on the side close to the straight line L1 that connects the tooth surface of the central gear 30 with the tooth surface at the shortest distance.

In the case of the speed reducer 210 of the present embodiment, when the input gear 33 is replaced, the support shaft is fitted on the base flange 14a according to a change in the distance between the tooth surfaces between the input gear 33 and the center gear 30 (output gear). The joint holes 45A and 45B can be appropriately selected, and the support shaft 39 of the intermediate gear 32 can be fixed in the optimum support shaft fitting holes 45A and 45B. Therefore, it is possible to change the reduction ratio of the input gear 33 and the center gear 30 (output gear) without replacing the support block such as the fixed block 14. Therefore, even when the speed reducer 210 of the present embodiment is adopted, the gear ratio of the input gear 33 and the center gear 30 (output gear) can be changed without requiring a large-scale replacement of parts, and the increase in parts cost can be suppressed. be able to.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist thereof.
For example, in the above description of the embodiment, the case where the input gear is replaced with another gear having a different number of teeth and an outer diameter has been described in detail, but the output gear (for example, the center gear) has a different number of teeth and an outer diameter. The position of the support shaft of the intermediate gear can be changed in the same manner when the gear is replaced with the above gear. Further, when both the input gear and the output gear are replaced with different gears, the position of the support shaft of the intermediate gear can be changed in the same manner.

Further, in the above embodiment, the intermediate gear and the input gear are rotatably supported on the fixed block side, but the intermediate gear and the input gear may be rotatably supported on the first carrier block side. ..

Hereinafter, a fourth embodiment of the gear mechanism and the speed reducer according to the present invention will be described with reference to the drawings.
FIG. 10 is a cross-sectional view showing a gear mechanism and a speed reducer according to the present embodiment, and FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. In the figure, reference numeral 301 is a speed reducer.

As shown in FIGS. 10 and 11, the speed reducer 301 according to the present embodiment transmits the rotational driving force of the motor (rotational drive source) 310 to the speed reduction unit (output unit) 330 via the gear mechanism 320 to reduce the speed. A predetermined reduction ratio is output as a rotational force around the output axis T0 of the unit 330.
The direction along the output axis T0 may be referred to as a vertical direction (vertical direction). The speed reducer 301 of the present embodiment can be applied to, for example, table driving of a turntable.

In the speed reducer 301, the gear mechanism 320 and the speed reduction unit 330 are housed in the casing 302. The motor 310 is attached to the outside of the casing 302. The motor 310 drives a drive shaft 310a along a drive axis (input axis) T10 extending in a substantially horizontal direction. An input shaft 311 having a coaxial input shaft line is attached to the drive shaft 310a. The input shaft 311 is rotatably supported by the casing 302. The gear mechanism 320 is interlocked with the input shaft 311. The speed reduction unit 330 outputs a rotation speed lower than the rotation speed input from the gear mechanism 320.

The motor 310 and the gear mechanism 320 are arranged so as to be adjacent to each other when viewed in the direction along the output axis T0. Similarly, the gear mechanism 320 and the reduction unit 330 are arranged so as to be adjacent to each other when viewed in the direction along the output axis T0. The positions of the motor 310 and the deceleration unit 330 in the vertical direction along the output axis T0 substantially overlap. The gear mechanism 320 is arranged at a position slightly lower than the motor 310 and the speed reducing unit 330 in the vertical direction along the output axis T0.

The gear mechanism 320 inputs the driving force from the center gear (third gear) 322 having the center axis T2 as the rotation axis, the idler gear (second gear) 323 that meshes with the center gear 322, and the idler gear 323 meshing with the motor 310. It includes an input gear (first gear) 321 input from 311. The center gear 322, the idler gear 323, and the input gear 321 are all spur gears and are arranged along the same horizontal plane.

The idler axis T3 of the idler gear 323, the input axis T1 of the input gear 321 and the center axis T2 of the center gear 322 are all parallel to the output axis T0. The center axis T2 of the center gear 322 coincides with the output axis T0.
The center gear 322 has the center axis T2 as the center of rotation. The idler gear 323 has the idler axis T3 as the center of rotation. The input gear 321 has the input axis T1 as the center of rotation.

The casing 302 has a base portion 302a, a first block 302b, and a second block 302c.
The base portion 302a is formed in a plate shape and is arranged along a horizontal plane orthogonal to the output axis T0. The base portion 302a is arranged along the lower surface of the speed reducer 301. On the upper surface of the base portion 302a, the first block 302b accommodating the gear mechanism 320 and the tubular second block 302c accommodating the deceleration portion 330 are arranged side by side when viewed in the direction along the output axis T0. ing.
The base portion 302a constitutes a support block that rotatably supports at least the input gear 321 and the center gear 322 and the idler gear 323.

The first block 302b and the second block 302c are connected to the upper surface of the base portion 302a in a side-by-side state. The first block 302b and the second block 302c project upward from the upper surface of the base portion 302a. The first block 302b and the base portion 302a are coupled to each other so that the inside of the speed reducer 301 can be sealed.

The tubular second block 302c is arranged so that its central axis coincides with the output axis T0. The first block 302b is arranged adjacent to the second block 302c. The upper end of the second block 302c is arranged along the upper surface of the speed reducer 301. The second block 302c is fastened to the upper surface of the base portion 302a by bolts 302j or the like. The second block 302c and the base portion 302a are coupled to each other so that the inside of the speed reducer 301 can be sealed.

The base portion 302a has a plate-shaped first base portion 302a1 and a plate-shaped second base portion 302a2 having a contour smaller than that of the first base portion 302a1. The first base portion 302a1 has a contour to which both the first block 302b and the second block 302c can be attached. The second base portion 302a2 has a contour corresponding to the first block 302b, and is fitted into the first base portion 302a1 integrally with the region corresponding to the first block 302b as described later. The first base portion 302a1 and the second base portion 302a2 are coupled to each other so as to be able to seal the internal space 328b of the speed reducer 301.
The first base portion 302a1 is formed to be thicker than the second base portion 302a2 so that the second base portion 302a2 can be fitted as described later. The second base portion 302a2 is exposed on the lower surface of the speed reducer 1. The second base portion 302a2 is integrally connected to the first base portion 302a1 at a position opposite to that of the first block 302b in the vertical direction.

The first block 302b has a first block side portion 302b1 integrally coupled to the upper surface of the first base portion 302a1 and a first block plate 302b2 integrally coupled to the upper surface of the first block side portion 302b1.
The first block side portion 302b1 projects upward from the upper surface of the plate-shaped first base portion 302a1. The first block plate 302b2 is coupled so as to close the inside of the first block side portion 302b1. The first block plate 302b2 is arranged substantially parallel to the first base portion 302a1 and the second base portion 302a2. The first block plate 302b2 is arranged along the upper surface of the speed reducer 301.
The tip of the input shaft 311 that transmits the rotational driving force of the motor 310 to the gear mechanism 320 penetrates through the first block 302b. The input shaft 311 faces the horizontal direction.

The motor 310 has a drive shaft 310a. The motor 310 is fixed to the side portion of the first block side portion 302b1. The tip of the drive shaft 310a is an input shaft 311 penetrating the casing 302.
A press-fit hole 311a into which the drive shaft 310a of the motor 310 is fitted is formed on the outer end surface of the input shaft 311. The motor 310 is fixed to a motor support member 326 attached to the first block 302b. The drive shaft 310a of the motor 310 is inserted into the press-fit hole 311a of the input shaft 311 in a posture in which the drive axis T10 extends in the horizontal direction (direction parallel to the base portion 302a). The motor 310 is located slightly above the upper and outer surfaces of the base portion 302a (on the side of the first block 302b).

A drive-side gear 311b is attached to the tip of the input shaft 311.
The drive-side gear 311b has a configuration in which teeth are formed at the outer end portion of a disk-shaped portion protruding in the radial direction from the outer peripheral surface of the input shaft 311. The driven side gear 311c meshes with the driving side gear 311b. The drive side gear 311b and the driven side gear 311c are made of bevel gears. The drive side gear 311b and the driven side gear 311c are not limited to the bevel gear, and the positional relationship between the drive axis T10 of the drive side three-wheeled wheel 11b and the input axis T1 of the input shaft 321a of the driven side gear 311c intersect. It is sufficient that the driving force can be transmitted from the driving side gear 311b to the driven side gear 311c. The driven side gear 311c has an input shaft 321a extending in the vertical direction as a rotation shaft. The driven side gear 311c is arranged close to the second block 302c in the vertical direction of the input shaft 321a.

The input shaft 321a is composed of a shaft member extending linearly concentrically with the rotation axis of the driven side gear 311c. The input shaft 321a is supported by a bearing 321g, which will be described later, in a posture in which the input shaft line T1 is orthogonal to the drive shaft line T10 of the input shaft 311. That is, the input shaft 321a is rotatably supported by the casing 302.
In the present embodiment, the drive axis T10 of the input shaft 311 is parallel to the upper surface of the speed reducer 301, and the input axis T1 of the input shaft 321a is orthogonal to the upper surface of the speed reducer 301.
The input axis T1 of the input shaft 321a and the drive axis T10 of the input shaft 311 are not limited to the orthogonal positional relationship, and may have a positional relationship other than parallel. For example, the drive axis T10 of the input shaft 311 can be tilted in the vertical direction so that the motor 310 side is lowered from the horizontal position.

The driven side gear 311c has a configuration in which teeth are formed at the outer end portion of a disk-shaped portion protruding in the radial direction from the outer peripheral surface of the input shaft 321a. The outer end portion of the driven side gear 311c is inserted into the enlarged diameter portion 328d1 formed in the first block 302b. As will be described later, the enlarged diameter portion 328d1 is located at the upper end position of the internal space 328d formed in the first block side portion 302b1 and is closed by the first block plate 302b2.

An internal space 328b is formed in the first base portion 302a1 in the middle in the vertical direction. The internal space 328b is formed along a horizontal plane orthogonal to the output axis T0.

The first base portion 302a1 is formed with two through holes 328a and through holes 328d2 penetrating in the vertical direction. Both the through hole 328a and the through hole 328d2 communicate with the internal space 328b.
The through hole 328a is arranged with the output axis T0 as the center line, and is formed in a shape concentric with the tubular second block 302c. The through hole 328a penetrates from the internal space 328b to the outside of the lower surface of the speed reducer 301.
The through hole 328d2 is formed at a position corresponding to the center of the input gear 321. The through hole 328d2 communicates from the internal space 328b to the internal space 328d of the first block 302b, which will be described later.

The input gear (first gear) 321 of the gear mechanism 320, the idler gear (second gear) 323, and the center gear (third gear) 322 are housed in the internal space 328b in a state of being meshed with each other. The internal space 328b is concentric with the center gear 322, a portion formed in a shape concentric with the input shaft (support shaft) 321a, and a portion formed in a shape concentric with the idler shaft (support shaft) 323a. It has a part corresponding to the shape and a continuous planar contour shape.

In the internal space 328b, the input gear 321 is connected to the input shaft 311 on the side that transmits the rotational driving force from the motor 310 as the gear mechanism 320. The idler gear 323 meshes with the input gear 321 inside the internal space 328b and is rotatably held by the first base portion 302a1 and the second base portion 302a2. The center gear 322 is located inside the internal space 328b and meshes with the idler gear 323 to transmit the rotation of the input gear 321.

The center gear 322 has a larger diameter than the input gear 321 and has a larger number of teeth than the input gear 321. Therefore, the rotation of the input gear 321 by the motor 310 is reduced to a predetermined reduction ratio and transmitted to the center gear 322 in that state.

The first base portion 302a1 is formed with an opening 328b1 at a lower position facing the input gear 321 and the idler gear 323 in the internal space 328b. The opening 328b1 is closed by fitting the second base portion 302a2 from below. The second base portion 302a2 is fixed at a position inserted halfway in the internal space 328b in the vertical direction.

In the first base portion 302a1, a diameter-expanded portion 328b2 having a step and being expanded in diameter is formed at the edge portion of the opening 328b1 that faces downward in the internal space 328b. A flange portion 302a2a formed so as to project around the second base portion 302a2 is fitted in the enlarged diameter portion 328b2. In this state, the surfaces of the enlarged diameter portion 328b2 and the flange portion 302a2a facing each other in the vertical direction come into contact with each other. As a result, the position of the second base portion 302a2 with respect to the first base portion 302a1 in the vertical direction is fixed. The diameter-expanded portion 328b2 may be formed up to the end portion that is the contour of the first base portion 302a1 in the horizontal direction. A sealing means such as an O-ring may be provided around the opening 328b1 at a position above the flange portion 302a2a.

The second base portion 302a2 is formed with a bottomed support hole 321f having a circular cross section on the inner surface of the internal space 328b.
A bearing 321 g is mounted in the support hole 321 f. The bearing 321g is attached to the inner peripheral surface of the support hole 321f. The bearing 321g supports the lower end of the input shaft 321a. The input shaft 321a has a vertical input axis T1 along the output axis T0. The lower end of the input shaft 321a is inserted into the support hole 321f. An input gear 321 is attached to the input shaft 321a in the vicinity of the lower end portion.

FIG. 12 is an explanatory view showing a shaft position changing portion in the present embodiment, and FIG. 13 is a cross-sectional view taken along the line XIII-XIII of FIG.
The second base portion 302a2 is formed with bottomed support holes (support hole portions) 351A, 351C, and 351E having a circular cross section on the inner surface of the internal space 328b.
The first base portion 302a1 is formed with bottomed support holes (support hole portions) 351B, 351D, and 351F having a circular cross section on the inner surface of the internal space 328b.
That is, the base portion 302a has a first base portion 302a1 and a second base portion 302a2 located on both sides of the idler gear 323 facing the axial direction of the idler gear 323, and the first base portion 32a1 and the second base portion 302a2. Support holes (support hole portions) 351A to 351F are formed on at least one facing surface of the above.

The support holes (support hole portions) 351A to 351F are shaft position changing portions 350 capable of changing the position of the idler shaft (support shaft) 323a of the idler gear 323 corresponding to the input gears 321 having different numbers of teeth. The support holes (support hole portions) 351A to 351F are all open to the internal space 328b. The support holes (support hole portions) 351A to 351F are all arranged along the circumference R50 at a predetermined distance from the input axis T1 which is the rotation center of the input gear 321.
Support holes (support hole portions) 351A to 351F are alternately arranged in the first base portion 302a1 and the second base portion 302a2 on the circumference R50. The support holes (support hole portions) 351A to 351F are arranged apart from each other on the circumference R50.

The tip of the columnar idler shaft 323a is inserted into any one of the support holes 351A to 351F. As a result, one of the support holes 351A to 351F into which the idler shaft 323a is inserted rotatably supports the idler shaft 323a. An idler gear 323 is connected to the idler shaft 323a.
The idler gear 323 is rotatably supported by selecting the insertion position of the idler shaft 323a from the support holes 351A to 351F. The idler shaft 323a has a vertical idler axis T3 along the output axis T0.

The support holes (support hole portions) 351A to 351F and the support holes 321f are formed so as to be separated from each other in a plane viewed in the direction along the output axis T0. Further, even if the insertion position of the idler shaft 323a is selected from the support holes 351A to 351F, the distance between the rotation centers of the input gear 321 and the idler gear 323 does not change.

Note that FIG. 10 shows a state in which the idler shaft 323a of the idler gear 323 is attached to the support hole (support hole portion) 351B among the support holes (support hole portions) 351A to 351F.
Here, the tip of the cylindrical idler shaft 323a is inserted into the support hole 351B. An idler gear 323 is connected to the idler shaft 323a.

An internal space 328d extending in the vertical direction is formed at a position of the first block side portion 302b1 facing the support hole 321f. The internal space 328d is formed so as to extend upward, and its lower end communicates with the internal space 328b via a through hole 328d2.
The internal space 328d has a circular cross section corresponding to the through hole 328d2. The upper end of the internal space 328d is closed by the first block plate 302b2. A bottomed support hole 321h having a circular cross section is formed at the lower surface position of the first block plate 302b2, which is inside the internal space 328d. A bearing 321 g is mounted in the support hole 321 h. The bearing 321g is attached to the inner peripheral surface of the support hole 321h. The bearing 321g supports the input shaft 321a. The upper end of the input shaft 321a is inserted into the support hole 321h.

In the first block 302b, an enlarged diameter portion 328d1 is formed at the upper end of the internal space 328d. The driven side gear 311c is housed in the enlarged diameter portion 328d1 at a position below the bearing 321g. The lower end of the first block plate 302b2 is fitted to the upper end of the internal space 328d. A flange portion 302b2a is provided so as to project outward in the radial direction around the upper end of the first block plate 302b2. The flange portion 302b2a is in contact with the upper end of the first block side portion 302b1, whereby the vertical position of the first block plate 302b2 with respect to the first block side portion 302b1 is fixed. At the same time, the first block side portion 302b1 and the first block plate 302b2 are brought into close contact with each other to seal the internal space 328d. On the outer peripheral surface of the first block plate 302b2, a sealing means such as an O-ring may be provided at a position below the flange portion 302b2a and inserted into the first block side portion 302b1.

In the first block 302b, near the lower end of the internal space 328d, a bearing 321g that supports the central position of the input shaft 321a in the axial direction is attached. The bearing 321g is attached to the inner peripheral surface of the internal space 328d in the first block side portion 302b1.
At the lower end of the first block side portion 302b1, which is the lower end position of the internal space 328d, a ridge 302b4 that protrudes downward is formed at a position around the through hole 328d2. The ridge 302b4 is inserted into the through hole 328d2 and is used for positioning the first block side portion 302b1 and the first base portion 302a1.

In the first block 302b, a through hole 328d4 extending in the horizontal direction is formed at the position of the internal space 328d corresponding to the enlarged diameter portion 328d1 in the vertical direction and the position below the internal space 328d. The through hole 328d4 is formed so as to extend from the input shaft 321a toward the motor 310. The drive side gear 311b is housed inside the through hole 328d4. On the outside of the through hole 328d4, an input shaft support portion 325 is continuously formed on the first block side portion 302b1 at a position surrounding the periphery of the input shaft 311. The input shaft support portion 325 has a tubular shape that surrounds the circumference of the input shaft 311, and a bearing 324 is arranged inside the input shaft support portion 325. The bearing 324 rotatably supports the input shaft 311. A motor support member 326 is fixed to the outside of the input shaft support portion 325 near the motor 310. The inside of the input shaft support portion 325 has a diameter dimension corresponding to the through hole 328d4. The input shaft support portion 325 and the first block side portion 302b1 accommodate the input shaft 311 and the drive side gear 311b and are sealed to the outside.

The first base portion 302a1 is formed with an opening 328b3 on the upper side of the internal space 328b facing the center gear 322. The opening 328b3 is closed by the second block 302c and the speed reducer 330. The opening 328b3 is formed in a planar contour shape centered on the output axis T0 and concentric with the second block 302c and the center gear 322.

In the internal space 328b, the center gear 322 is rotatably supported by the tubular body 334.
The tubular body 334 penetrates the internal space 328b in the vertical direction. The tubular body 334 is arranged around the output axis T0. The cylinder 334 penetrates the speed reducer 301 in the vertical direction. The lower end of the tubular body 334 is fitted into the through hole 328a. A seal member 334b may be provided between the lower end of the tubular body 334 and the inner surface of the through hole 328a. A flange portion 334a exposed on the upper surface of the deceleration portion 330 is formed at the upper end of the tubular body 334. The flange portion 334a is formed so as to be recessed downward with respect to the upper surface of the speed reducer 301. The tubular body 334 is arranged substantially in the center of the opening 328b3.

A coaxial gear 322d is integrally formed on the center gear 322. The gear 322d has a smaller number of teeth than the center gear 322 and has a smaller diameter. The center gear 322 and the gear 322d can rotate around the cylinder 334 as a unit. The gear 322d is arranged above the center gear 322. The gear 22d is arranged closer to the reduction gear 330 than the center gear 322. The gear 322d is the input side to the reduction unit 330. The gear 322d is housed inside the opening 328b3. The lower end of the center gear 322 is rotatably supported in the vicinity of the through hole 328a via the bearing 334c. The upper end of the center gear 322 is rotatably supported with respect to the reduction gear 330 via the bearing 334c.

The speed reduction unit 330 is housed in a tubular second block 302c fixed to the first base unit 302a1. The speed reduction unit 330 may be, for example, an eccentric swing type speed reduction mechanism. The speed reduction unit 330 has a carrier 333 arranged inside the second block 302c, and a transmission shaft 331 that rotates with the rotation of the center gear 322.

The carrier 333 is rotatable relative to the second block 302c about the output axis T0. Specifically, the relative rotation of the second block 302c and the carrier 333 is allowed by the bearing 336 provided between the inner circumference of the second block 302c and the outer circumference of the carrier 333. The carrier 333 is exposed on the upper surface of the deceleration unit 330. The carrier 333 is on the output side of the deceleration unit 330. The lower end of the speed reduction unit 330 faces the opening 328b3. A tubular body 334 penetrates the central portion of the carrier 333. The axis of the carrier 333 coincides with the output axis T0, which is the axis of the cylinder 334. The tubular body 334 may be fixed to, for example, a carrier 333.

The transmission shaft 331 is the input side of the speed reduction unit 330 to which the rotational driving force is transmitted from the center gear 322. The transmission shaft 331 is rotatably attached to the carrier 333 about a direction parallel to the output axis T0. The speed reduction unit 330 relatively rotates the second block 302c and the carrier 333 at a speed slower than the rotation speed of the transmission shaft 331 based on the rotation of the transmission shaft 331. The transmission shaft 331 is provided with a transmission gear 332 that meshes with the gear 322d. The transmission gear 332 is a spur gear. The transmission gear 332 is arranged above the center gear 322.

The speed reducer 301 of the present embodiment may be fixed to a flat speed reducer mounting surface. Then, in this state, a turntable or the like may be placed on the upper surface of the carrier 333. In this case, the turntable is fixed to the upper surface of the carrier 333 by a fastening bolt or the like.

In the speed reducer 301, when the motor 310 is driven, the drive shaft 310a rotates, and the input shaft 311 coaxially integrated with the drive shaft 310a rotates. As a result, the driven side gear 311c that meshes with the drive side gear 311b provided on the input shaft 311 is driven, and the input shaft 321a of the gear mechanism 320 rotates around the input shaft line T1. When the input shaft 321a rotates, the input gear 321 coupled to the input shaft 321a rotates around the input shaft line T1. Due to the rotation of the input gear 321, the idler gear 323 meshed with the input gear 321 rotates around the idler shaft 323a. When the idler gear 323 rotates, the center gear 322 meshing with the idler gear 323 rotates around the output axis T0. When the center gear 322 rotates, the coaxial gear 322d integrated with the center gear 322 rotates. As a result, the transmission gear 332 that meshes with the gear 322d rotates, and the transmission shaft 331 integrated with the transmission gear 332 rotates. Due to the rotation of the transmission shaft 331, the second block 302c, which is the outer cylinder of the deceleration unit 330, and the carrier 333 rotate relatively at a speed slower than the rotation speed of the transmission shaft 331. This causes the turntable to rotate.

In the speed reducer 301 of the present embodiment, different gear ratios can be selected and set by selecting a plurality of types of input gears 321 and matching the mounting positions of the idler gears 323 with the shaft position changing unit 350.
In FIGS. 12 and 13, six support holes (support hole portions) 351A to 351F are shown as shaft position changing portions 350, of which the idler shaft 323a of the idler gear 323 is inserted into the support hole 351A.
The support hole 351F is arranged so that the idler axis T3 is on a straight line connecting the input axis T1 and the center axis T2 when viewed in the direction along the input axis T1.
Further, the support holes 351A to 351E are arranged in the order of distance from the support hole 351E to the support hole 351D so as to increase the distance from the straight line connecting the input axis T1 and the center axis T2 when viewed in the direction along the input axis T1. , Support hole 351C, support hole 351B, and support hole 351A are arranged in this order. The support hole 351A is the farthest from the straight line connecting the input axis T1 and the center axis T2 among the support holes 351A to 351F.

Here, the input gear 321 (A) has the largest outer diameter and the number of teeth in the speed reducer 301 of the present embodiment. In this case, the idler gear 323 has the idler shaft 323a inserted into the support hole 351A. The idler gear 323 is attached to the first base portion 302a1 of the base portion 302a using the support hole 351A.

On the other hand, as shown by virtual lines in FIGS. 12 and 13, when the input gear 321 (D) having a smaller outer diameter and the number of teeth than the input gear 321 (A) is applied, the idler gear 323 , The idler shaft 323a is inserted into the support hole 351D. The idler gear 323 is attached to the second base portion 302a2 of the base portion 302a using the support hole 351D.

Similarly, by attaching the idler gear 323 to the base portion 302a using any of the support holes 351A to 351F, it is possible to correspond to the input gear 321 having a different outer diameter and the number of teeth.

In the speed reducer 301 of the present embodiment, when the speed reducer 301 is replaced with an input gear 321 having a different outer diameter and the number of teeth, the distance between the tooth surfaces between the input gear 321 and the center gear 322 is changed according to the change. The idler shaft 323a of the idler gear 323 can be fixed at an optimum position by appropriately selecting from a plurality of support holes 351A to 351F formed in the base portion 302a as the shaft position changing portion 350.
Therefore, the reduction ratio between the input gear 321 and the center gear 322 can be changed and the change range can be further expanded without replacing the support block such as the base portion 302a. As a result, when the speed reducer 301 of the present embodiment is adopted, the range of change in the gear ratio between the input gear 321 and the center gear 322 can be expanded without requiring a large-scale replacement of parts, and the rise in parts cost can be suppressed. can do.

Further, by arranging a plurality of support holes 351A to 351F along the circumference R50, the idler gear 323 is attached to the input gears 321 (A) to (F) having different outer diameters and the number of teeth. By simply changing the position, the range for changing the gear ratio between the input gear 321 and the center gear 322 can be expanded, and soaring component costs can be suppressed.

A plurality of support holes 351A to 351F are alternately arranged in the first base portion 302a1 and the second base portion 302a2 on the circumference R50, so that one side of the first base portion 302a1 and the second base portion 302a2 is provided. Therefore, it is possible to deal with fine fluctuations in the gear ratio as compared with the case where a plurality of support holes 351A to 351F are arranged. Moreover, even when the gear ratio fluctuates finely, the distance between the adjacent support holes 351A to 351F is set within a range having sufficient strength in either the first base portion 302a1 or the second base portion 302a2. be able to.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist thereof.
For example, in the description of the above embodiment, an example in which six support holes 351A to 351F are arranged is shown, but the present invention is not limited to this. Further, support holes 351A to 351F are alternately arranged in the first base portion 302a1 and the second base portion 302a2, but the present invention is not limited to this. The arrangement of the shaft position changing unit 350 can be appropriately changed according to the gear ratio between the input gear 321 and the center gear 322 to be set.

Further, in the present embodiment, the speed reducer 301 is used for driving the turntable as a configuration in which the speed reducer 301 is placed on a surface extending in the horizontal direction, but the present invention is not limited to this configuration and application. .. The speed reducer 301 in the present embodiment may be fixed to a mounting surface extending in a direction other than horizontal.
Further, in the speed reduction unit 330, the output side has been described as the carrier 333, but the present invention is not limited to this configuration, and any one of the carrier 333 and the tubular second block 302c may be the output side.

The gear mechanism according to the present invention is not limited to being applied to the speed reducer 301 of the above-described embodiment, and may be applied to any machine or device.

1 ... Drive device, 2 ... Motor (rotary drive source), 10,110,210,301 ... Reducer, 13 ... Rotating block, 14 ... Fixed block (support block), 15A ... First carrier block (support block), 30 ... Central gear (output gear), 32 ... Intermediate gear, 33 ... Input gear, 38, 38A ... Mounting base (support block), 39, 239 ... Support shaft, 40, 40A ... Holding member, 40a ... Connected to the support shaft Part (holding part), 41 ... holding hole, 45A, 45B ... support shaft fitting hole, c2 ... axis, 302a1 ... first base part (support block), 302a2 ... second base part (support block), 320 ... Gear mechanism, 321 ... Input gear (first gear), 321a ... Input shaft (support shaft), 322 ... Center gear (third gear), 322a ... Center shaft (support shaft), 323 ... Idler gear (second gear), 323a ... Idler (support shaft), 350 ... Shaft position change part, 351A to 351F ... Support hole (support hole part)

Claims (15)

Support block and
An input gear rotatably supported by the support block,
An intermediate gear that meshes with the input gear,
An output gear that meshes with the intermediate gear and
A gear position changing mechanism capable of changing the positions of the intermediate gear with respect to the input gear and the output gear, and
The reducer equipped with. The speed reducer according to claim 1, wherein the gear position changing mechanism holds a support shaft of the intermediate gear and includes a holding member that is detachably attached to the support block. The holding member has a holding portion of the support shaft at a position separated from a reference position on the holding member.
The holding member and the support block have a rotation position changing portion capable of changing the rotation position of the holding member about the reference position.
The speed reducer according to claim 2, wherein the gear position changing mechanism includes the holding portion of the holding member and the rotating position changing portion. The holding member is formed in a columnar shape centered on the reference position.
The support block has a circular holding hole into which the outer peripheral surface of the holding member is fitted.
The speed reducer according to claim 3, wherein the rotation position changing portion has an outer peripheral surface of the holding member and the holding hole. The speed reducer according to claim 4, wherein the support shaft is integrally formed with the holding portion of the holding member. Support block and
An input gear rotatably supported by the support block,
An intermediate gear that meshes with the input gear,
An output gear that meshes with the intermediate gear and
A holding member that holds the support shaft of the intermediate gear and is detachably attached to the support block is provided.
The holding member is formed in a columnar shape, and the support shaft is integrally formed at a position separated from the axial center position of the holding member.
The support block has a circular holding hole into which the outer peripheral surface of the holding member is fitted.
The outer peripheral surface of the holding member and the holding hole of the support block form a speed reducer that constitutes a rotation position changing portion capable of changing the rotation position about the axis of the holding member. Support block and
An input gear rotatably supported by the support block,
An intermediate gear that meshes with the input gear,
An output gear that meshes with the intermediate gear and
A shaft position changing portion that can change the position of the support shaft of the intermediate gear,
The reducer equipped with. The support block has a plurality of support shaft fitting holes into which the support shaft can be fitted.
The speed reducer according to claim 7, wherein the shaft position changing portion is composed of a plurality of the support shaft fitting holes. A speed reducer that slows down the rotation of the rotary drive source and outputs it,
A drive device including a rotating block connected to the output unit of the speed reducer.
The speed reducer
Support block and
An input gear rotatably supported by the support block,
An intermediate gear that meshes with the input gear,
An output gear that meshes with the intermediate gear and
A gear position changing mechanism capable of changing the positions of the intermediate gear with respect to the input gear and the output gear, and
The drive device equipped with. Support block and
The first gear rotatably supported by the support block,
The second gear that meshes with the first gear,
The third gear that meshes with the second gear,
A shaft position changing portion capable of changing the position of the support shaft of the second gear corresponding to the third gear having a different number of teeth,
Gear mechanism with. The gear mechanism according to claim 10, wherein the shaft position changing portion has a plurality of support hole portions formed apart from the support block so that the inserted support shaft can be rotatably supported. The gear mechanism according to claim 11, wherein the support block has a plurality of support holes along a circumference at a predetermined distance from the rotation center of the first gear. The support block has a first base portion and a second base portion located on both sides of the second gear so as to face the axial direction of the second gear.
The gear mechanism according to claim 11 or 12, wherein the support hole portion is provided on at least one facing surface of the first base portion and the second base portion. The support block is arranged along a circumference at a predetermined distance from the rotation center of the first gear, and the facing surface of the first base portion and the facing surface of the second base portion on the circumference. The gear mechanism according to claim 13, further comprising the plurality of support holes arranged alternately with and. The support block, the first gear rotatably supported by the support block, the second gear that meshes with the first gear, the third gear that meshes with the second gear, and the third gear with a different number of teeth. A gear mechanism including a shaft position changing portion capable of changing the position of the support shaft of the second gear, and
A speed reducer connected to the gear mechanism and
A reducer equipped with.

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