TWI845650B - Gear mechanism, speed reducer, and driving device using speed reducer - Google Patents

Abstract

The speed reducer of the present invention comprises: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; and a gear position changing mechanism capable of changing the position of the intermediate gear relative to the input gear and the output gear.

Description

Gear mechanism, speed reducer, and driving device using speed reducer

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

In industrial robots or machine tools, a speed reducer is used to reduce the speed of a rotary drive source such as a motor. In the speed reducer, there is a case where an intermediate gear is inserted between the input gear and the output gear and engages with the two gears (for example, refer to Patent Document 1).

The input gear and output gear of this type of reducer are rotatably supported on a support block of the output rotor or housing. The intermediate gear is similarly rotatably supported on a support block of the output rotor or housing, and engages with the input gear and the output gear. The rotation of the input gear is reduced in speed at a speed ratio corresponding to the ratio of the number of teeth of the output gear to the input gear, and is transmitted to the output gear. The support shaft of the intermediate gear is fixed to the retaining hole of the support block at a position where the tooth surface of the intermediate gear engages with the two tooth surfaces of the input gear and the output gear.

[Prior Art Literature]

[Patent Literature]

[Patent document 1] Japanese Patent No. 5231530

In this type of speed reducer, the input gear may be replaced with another input gear with a different number of teeth for the purpose of changing the reduction ratio. In this case, if a new input gear is installed on the output shaft of the drive source, the distance between the input gear and the output gear changes. Therefore, in order to align 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, the support block of the output rotating body or outer casing that fixes the support shaft of the intermediate gear must be replaced with another component with a different position of the retaining hole. In addition, when the output gear is replaced with a component with a different number of teeth, the support block must also be replaced for the same reason.

Therefore, in previous speed reducers, when the input gear and the output gear are replaced with components with different numbers of teeth, large-scale parts replacement is required, and the parts cost is high.

The present invention provides a speed reducer that can change the speed ratio of the input gear and the output gear without large-scale parts replacement and can suppress the increase in parts cost, and a driving device using the speed reducer.

The present invention further provides a gear mechanism, a speed reducer, and a drive device using the speed reducer that can expand the range of speed ratio changes without large-scale parts replacement and suppress the increase in parts costs.

A speed reducer according to one aspect of the present invention comprises: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; and a gear position changing mechanism capable of changing the position of the intermediate gear relative to the input gear and the output gear.

According to the above structure, 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 in accordance with the change in the distance between the gear surfaces of the input gear and the output gear. In this structure, the speed reduction ratio of the input gear and the output gear can be changed without replacing the support block. Therefore, the speed ratio of the input gear and the output gear can be changed without large-scale parts replacement, and the increase in parts cost can be suppressed.

The aforementioned gear position changing mechanism may have a retaining member, which retains the supporting shaft of the aforementioned intermediate gear and is detachably mounted on the aforementioned supporting block.

In this case, the position of the intermediate gear can be changed by changing the assembly direction of the retaining member relative to the support block and the retaining member itself.

The structure may be as follows: the aforementioned retaining member has a retaining portion of the aforementioned support shaft at a position separated from the reference position on the retaining member, the aforementioned retaining member and the aforementioned support block have a rotational position changing portion that can change the rotational position of the aforementioned retaining member centered on the aforementioned reference position, and the aforementioned gear position changing mechanism has the aforementioned retaining portion of the aforementioned retaining member and the aforementioned rotational position changing portion.

When at least one of the input gear and the output gear is replaced, the rotational position of the retaining member around the reference position is changed by the rotational position changing portion in accordance with the change in the distance between the tooth surfaces of the input gear and the output gear. In this way, the position of the support shaft of the intermediate gear is changed when the retaining member is mounted on the support block. When this structure is adopted, the position of the intermediate gear can be easily changed by simply changing the rotational position of the retaining member.

The structure may be as follows: the aforementioned retaining member is formed into a cylindrical shape with the aforementioned reference position as the axis, the aforementioned support block has a circular retaining hole for the outer peripheral surface of the aforementioned retaining member to fit into, and the aforementioned rotational position changing portion has: the outer peripheral surface of the aforementioned retaining member, and the aforementioned retaining hole.

When at least one of the input gear and the output gear is replaced, the rotation angle of the retaining member around the axis is appropriately changed in accordance with the change in the distance between the tooth surfaces of the input gear and the output gear, and the retaining member is engaged in the retaining hole of the support block in this state.

The aforementioned support shaft can be integrally formed in the aforementioned retaining portion of the aforementioned retaining member.

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

A speed reducer of one aspect of the present invention comprises: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; and a retaining member that retains the support shaft of the intermediate gear and is detachably mounted on the support block; the retaining member is formed in a cylindrical shape, and the support shaft is integrally formed at a position separated from the axial position of the retaining member; the support block has a circular retaining hole for the outer peripheral surface of the retaining member to fit; the outer peripheral surface of the retaining member and the retaining hole of the support block constitute a rotation position changing portion that can change the rotation position of the retaining member centered on the axis.

According to the above-mentioned structure, when at least one of the input gear and the output gear is replaced, the rotation position of the retaining member is appropriately changed according to the change in the distance between the gear surfaces of the input gear and the output gear, and the outer peripheral surface of the retaining member is engaged with the retaining hole of the support block. Thereby, the position of the middle gear on the support block is changed. In this structure, the speed reduction ratio of the input gear and the output gear can be changed only by changing the rotation position of the retaining member relative to the retaining hole of the support block. Therefore, the speed ratio of the input gear and the output gear can be changed without large-scale parts replacement, and the increase in parts cost can be suppressed.

A speed reducer according to one aspect of the present invention comprises: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; and an axis position changing section capable of changing the position of the support axis of the intermediate gear.

When at least one of the input gear and the output gear is replaced, the position of the support shaft of the intermediate gear is changed by the shaft position changing part in accordance with the change in the distance between the tooth surfaces of the input gear and the output gear. In this structure, the speed reduction ratio of the input gear and the output gear can be changed without replacing the support block.

It is feasible that the aforementioned support block has a plurality of support shaft fitting holes for the aforementioned support shaft to fit into, and the aforementioned shaft position changing portion is composed of a plurality of the aforementioned support shaft fitting holes.

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

The driving device of one aspect of the present invention comprises: a speed reducer, which reduces the speed of the rotation of the rotation driving source and outputs it; and a rotating block, which is connected to the output portion of the speed reducer; and the speed reducer comprises: a support block; an input gear, which is rotatably supported by the support block; an intermediate gear, which is engaged with the input gear; an output gear, which is engaged with the intermediate gear; and a gear position changing mechanism, which can change the position of the intermediate gear relative to the input gear and the output gear.

A gear mechanism of one aspect of the present invention comprises: a support block; a first gear rotatably supported by the support block; a second gear engaged with the first gear; a third gear engaged with the second gear; and an axis position changing section capable of changing the position of the support axis of the second gear in correspondence with the third gear having a different number of teeth.

Thus, the shaft position changing part can change the position of the supporting shaft of the second gear in correspondence with the third gear having a different number of teeth, thereby corresponding to the change in the distance between the tooth surfaces of the third gear and the second gear, and the change range of the speed ratio between the first gear and the third gear can be enlarged without replacing the supporting block.

The shaft position changing portion mentioned above in the present invention may have a plurality of supporting holes, which can support the inserted supporting shaft in a rotatable manner and are separately formed in the aforementioned supporting block.

The aforementioned support block of the present invention may have a plurality of the aforementioned support holes along a circumference located at a specific distance from the rotation center of the aforementioned first gear.

The aforementioned support block of the present invention may have a first base portion and a second base portion that are axially opposite to the aforementioned second gear and located on both sides of the aforementioned second gear; and the aforementioned support hole portion is provided on the opposing surface of at least one of the aforementioned first base portion and the aforementioned second base portion.

The present invention arranges a plurality of the aforementioned supporting holes along a circumference located at a specific distance from the rotation center of the aforementioned first gear, and the aforementioned supporting holes are alternately formed on the aforementioned opposing surface of the aforementioned first base portion and the aforementioned opposing surface of the aforementioned second base portion on the aforementioned circumference.

A speed reducer of one aspect of the present invention comprises: a gear mechanism; and a speed reduction unit connected to the gear mechanism; and the gear mechanism comprises: a support block; a first gear rotatably supported by the support block; a second gear engaged with the first gear; a third gear engaged with the second gear; and an axis position changing unit capable of changing the position of the support axis of the second gear corresponding to the third gear having a different number of teeth.

The aforementioned circumference of the plurality of supporting holes is centered on the rotation center of the aforementioned first gear, and the radius of the aforementioned circumference may be consistent with the distance from the rotation center of the aforementioned first gear to the rotation center of the aforementioned second gear.

The above-mentioned speed reducer and drive device can change the speed ratio of the input gear and the output gear without large-scale parts replacement. Therefore, when the above-mentioned speed reducer and drive device are adopted, the increase in parts cost can be suppressed.

Furthermore, the gear mechanism, reducer, and drive device mentioned above can change the speed ratio without large-scale parts replacement, and the range of speed ratio change can be expanded.

Therefore, by using the above-mentioned gear mechanism, speed reducer and drive device, the increase in parts cost can be suppressed.

1: Drive device

2,310: Motor (rotational drive source)

3: Operating equipment

10,110,210,301: speed reducer

11: Base block

12: Holding device

13: Rotating block

13a: Workpiece support surface

14: Fixed block (support block)

14a: Base flange

14b: Feet

15A: 1st carrier block (support block)

15B: 2nd carrier block

15Ba: substrate part

16,22,34,35A,35B,321g,324,334c,336: Bearings

17: Outer tube

18: Crankshaft

18a, 18b: eccentric part

19A: 1st rotating gear

19Aa,19Ba,30a,31a,33a: external teeth

19B: 2nd rotating gear

20: Internal tooth pin

21,321f,321h: Support hole

23: Eccentric bearing

25,328a,328d2,328d4:Through hole

26: Output board

27: Cylinder

28: Concave part

30: Central gear (output gear)

31: Crankshaft gear

32: Middle gear

33,33(A),33(B): Input gear

36: Concave part

38,38A: Mounting base (support block)

39,239:Support axis

40,40A: Retaining member

40Aa: Chamfered part

40a: The part connected to the support shaft (retaining part)

41,41A: Holding hole

41Aa: plane

45A, 45B: Support shaft fitting hole

50: Fastening fixing part

302: Shell

302a: base part

302a1: First base part (support block)

302a2: Second base part (support block)

302a2a,302b2a,334a: flange

302b: The first block

302b1: Side of the first block

302b2: The first block plate

302b4: protrusion

302c: Second block

302j: Bolt

310a: Drive shaft

311: Input shaft

311a: Press-in hole

311b: Drive side gear

311c: Driven side gear

320: Gear mechanism

321: Input gear (first gear)

321(A):Input gear

321(D): Input gear

321a: Input shaft (support shaft)

322: Center gear (third gear)

322a: Center axis (support axis)

322d: Gear

323: Idle gear (second gear)

323a: Idle shaft (support shaft)

325: Input shaft support part

326: Motor support component

328b,328d:Inner space

328b1,328b3: Opening

328b2,328d1: Expansion

330: Speed reduction unit (output unit)

331:Transfer axis

332: Transmission gear

333:Carrier

334: Cylinder

334b: Sealing component

350: Axis position changing unit

351A~351F: Support hole (support hole part)

c1: rotation center axis

c2,c3: axis

c4: rotation center axis

F: Ground

III-III,V-V,XI-XI,XIII-XIII: line

L1: Straight line

o1: axis

R50: Circumference

T0: output axis

T1: Input axis

T2: Central axis

T3: Idle axis

T10: driving axis (input axis)

W: Workpiece

Figure 1 is a three-dimensional diagram of the driving device of the first embodiment.

Figure 2 is a front view of the reducer of the first embodiment.

FIG3 is a cross-sectional view of the reducer of the first embodiment along the III-III line of FIG2.

FIG4 is a cross-sectional view showing an enlarged portion of FIG3 of the speed reducer of the first embodiment.

FIG5 is a cross-sectional view of the reducer of the first embodiment taken along the V-V line of FIG3 .

FIG6 is a cross-sectional view of the reducer of the first embodiment taken along the V-V line of FIG3 .

FIG7 is a cross-sectional view of the speed reducer of the second embodiment corresponding to a portion of FIG5 .

FIG8 is a cross-sectional view of the speed reducer of the second embodiment corresponding to a portion of FIG6 .

Figure 9 is a cross-sectional view of the interior of the reducer of the third embodiment.

Figure 10 is a cross-sectional view of the gear mechanism and reducer of the fourth embodiment.

FIG11 is a cross-sectional view of the gear mechanism and reducer of the fourth embodiment along the XI-XI line of FIG10

Figure 12 is an explanatory diagram of the axis position changing portion of the fourth embodiment.

FIG13 is a cross-sectional view of the gear mechanism and reducer of the fourth embodiment along the XIII-XIII line of FIG12 .

Next, the implementation form of the present invention is described based on the drawings. In addition, in each implementation form described below, the same symbol is given to the common part, and some repeated descriptions are omitted.

(First implementation form)

First, the first implementation form shown in Figures 1 to 6 is explained.

Figure 1 is a three-dimensional diagram of a driving device 1 used for welding or parts assembly.

The drive device 1 comprises: a base block 11, which is set on the ground F; a speed reducer 10, which is fixedly set on the upper surface of one end side of the base block 11 in the longitudinal direction; a rotation drive source, i.e., a motor 2, which outputs power to the speed reducer 10; a retaining device 12, which is fixedly set on the upper surface of the other end side of the base block 11 in the longitudinal direction; and a rotating block 13, which is supported at both ends in the longitudinal direction by the speed reducer 10 and the retaining device 12. The motor 2 is integrally mounted on the input side of the speed reducer 10. The speed reducer 10 reduces the rotation of the motor 2 and transmits the rotation to one end side of the rotating block 13 in the longitudinal direction. The holding device 12 supports the other end of the rotating block 13 in a rotatable manner. The rotating block 13 rotates around the axis o1 roughly in the horizontal direction by receiving power from the motor 2 via the speed reducer 10.

In the present embodiment, the rotating block 13 has a plurality of workpiece support surfaces 13a around the axis o1. A workpiece W, which is a work object, is mounted on each workpiece support surface 13a. The workpiece W mounted on the workpiece support surface 13a moves toward the working position by the rotation of the rotating block 13 caused by the motor 2. A working device 3 such as a welding robot is provided at the working position.

FIG. 2 is a front view of the reducer 10 observed from the output side (the side for installing the rotating block 13), and FIG. 3 is a cross-sectional view along the III-III line of FIG. 2. FIG. 4 is a cross-sectional view of the reducer 10 with a portion of FIG. 3 enlarged, and FIG. 5 is a cross-sectional view of the reducer 10 roughly along the V-V line of FIG. 4. In addition, FIG. 5 does not show the cross-section of the central gear 30, the crankshaft gear 31, the intermediate gear 32, etc. described later. In FIG. 5, the retaining member 40 and the mounting base 38 described later are recorded at the same time.

The speed reducer 10 includes: a fixed block 14, whose lower end is fixedly arranged on the upper surface of one end side of a base block 11 (refer to FIG. 1); a first carrier block 15A and a second carrier block 15B, which are integrally combined with the fixed block 14; an outer cylinder 17, which is rotatably supported on the outer periphery of the first carrier block 15A and the second carrier block 15B via a bearing 16; a plurality of (three) crank shafts 18, which are rotatably supported on the first carrier block 15A and the second carrier block 15B; and a first rotating gear 19A and a second rotating gear 19B, which rotate together with two eccentric portions 18a, 18b of each crank shaft 18. The speed reducer 10 is installed on the base block 11 in such a way that the rotation center axis c1 of the output portion coincides with the axis o1 of the drive device 1.

The fixing block 14 has a perforated disc-shaped base flange 14a having a circular through hole 25 in the center (see FIG. 3 ), and a foot 14b extending downward from the base flange 14a (see FIG. 2 ). The lower end of the foot 14b of the fixing block 14 is fixed to the base block 11 by bolt fastening or the like. A perforated disc-shaped first carrier block 15A is stacked on one end face in the thickness direction of the base flange 14a, and the first carrier block 15A is fixed integrally by bolt fastening or the like. In addition, the second carrier block 15B is fixed to the end face of the first carrier block 15A on the opposite side to the base flange 14a by bolt fastening or the like. The second carrier block 15B has: a perforated disc-shaped substrate portion 15Ba, and a plurality of pillar portions not shown extending from the end face of the substrate portion 15Ba toward the first carrier block 15A. The end face of the pillar portion of the second carrier block 15B is butted against the end face of the first carrier block 15A, and each pillar portion is fixed to the first carrier block 15A. An axial gap is ensured between the first carrier block 15A and the substrate portion 15Ba of the second carrier block 15B. The first rotating gear 19A and the second rotating gear 19B are arranged in the gap.

In addition, the first rotating gear 19A and the second rotating gear 19B are provided with escape holes (not shown) through which the pillars of the second carrier block 15B pass. The escape holes are formed with a sufficiently large inner diameter relative to the pillars so that the pillars do not hinder the rotation of the first rotating gear 19A and the second rotating gear 19B.

The outer cylinder 17 is arranged to straddle the outer circumference of the first carrier block 15A and the outer circumference of the base plate portion 15Ba of the second carrier block 15B. Both axial ends of the outer cylinder 17 are rotatably supported by the first carrier block 15A and the base plate portion 15Ba of the second carrier block 15B via bearings 16. In addition, a plurality of pin grooves (not shown) extending parallel to the rotation center axis c1 are formed on the inner circumference of the axial center region of the outer cylinder 17 (region opposite to the outer circumference of the first rotating gear 19A and the second rotating gear 19B). A substantially cylindrical inner gear pin 20 is rotatably received in each pin groove. The plurality of inner gear pins 20 mounted on the inner circumference of the outer cylinder 17 face the outer circumferences of the first rotating gear 19A and the second rotating gear 19B.

The first rotating gear 19A and the second rotating gear 19B are formed with an outer diameter slightly smaller than the inner diameter of the outer cylinder 17. On the outer peripheral surfaces of the first rotating gear 19A and the second rotating gear 19B, outer teeth 19Aa and 19Ba are formed to be in contact with a plurality of inner gear pins 20 arranged on the inner peripheral surface of the outer cylinder 17 in a meshed state. The number of outer teeth 19Aa and 19Ba formed on the outer peripheral surfaces of the first rotating gear 19A and the second rotating gear 19B is set to be slightly less than the number of inner gear pins 20 (for example, one less).

A plurality of crankshafts 18 are arranged on the same circumference with the rotation center axis c1 of the first carrier block 15A and the second carrier block 15B as the center. Each crankshaft 18 is rotatably supported by the first carrier block 15A and the second carrier block 15B via a bearing 22. The eccentric portions 18a and 18b of each crankshaft 18 respectively penetrate the first rotating gear 19A and the second rotating gear 19B. Each eccentric portion 18a and 18b is rotatably engaged with a support hole 21 formed in the first rotating gear 19A and the second rotating gear 19B respectively via an eccentric portion bearing 23. In addition, the two eccentric portions 18a and 18b of each crankshaft 18 are eccentric in a manner that the phase is offset by 180° around the axis of the crankshaft 18.

If the plurality of crankshafts 18 receive external force and rotate in one direction, the eccentric parts 18a and 18b of the crankshaft 18 rotate in the same direction with a specific radius, and accordingly, the first rotating gear 19A and the second rotating gear 19B rotate in the same direction with the same radius. At this time, the outer teeth 19Aa and 19Ba of the first rotating gear 19A and the second rotating gear 19B are in contact with the plurality of inner gear pins 20 retained on the inner circumference of the outer cylinder 17 in an engaging manner.

In the speed reducer 10 of this embodiment, since the number of the inner gear pins 20 on the outer cylinder 17 side is set slightly larger than the number of the outer teeth 19Aa and 19Ba of the first rotating gear 19A and the second rotating gear 19B, the outer cylinder 17 is pushed in the same direction as the rotating direction at a specific pitch during one rotation of the first rotating gear 19A and the second rotating gear 19B. As a result, the rotation of the crankshaft 18 is greatly reduced and output as the rotation of the outer cylinder 17. In addition, in this embodiment, since the eccentric portion 18a and the eccentric portion 18b of each crankshaft 18 are eccentric in a manner offset by 180° around the axis, the rotation phases of the first rotating gear 19A and the second rotating gear 19B are offset by 180°.

A perforated circular plate-shaped output plate 26 is installed at the axial end of the outer cylinder 17 on the opposite side of the base flange 14a. The output plate 26 covers the end of the second carrier block 15B in a non-contact state, and the rotating block 13 for workpiece holding can be installed on the end surface on the axial outer side by bolt tightening (refer to Figure 1). In addition, a cylinder 27 is installed on the inner periphery of the output plate 26, which passes through the inner peripheries of the second carrier block 15B, the second rotating gear 19B, the first rotating gear 19A, the first carrier block 15A, and the base flange 14a in a non-contact state. The cylinder 27 rotates integrally with the output plate 26.

The speed reducer 10 also includes an input gear 33 connected to a not-shown rotating shaft of the motor 2, a central gear 30 (output gear) rotatably supported by the base flange 14a and the inner peripheral surface of the first carrier block 15A, and an intermediate gear 32 engaged with the input gear 33 and the central gear 30 to transmit the rotation of the input gear 33 to the central 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 caused by the motor 2 is reduced in speed at a specific reduction ratio and is transmitted to the central gear 30 in this state.

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

The center gear 30 is formed to span the axial length of the base flange 14a and the first carrier block 15A. An outer gear 30a is formed in the axial central area of the center gear 30. One end side of the center gear 30 in the axial direction is rotatably held on the inner circumference of the through hole 25 of the base flange 14a via a bearing 35A. The other end side of the center gear 30 in the axial direction is rotatably held on the inner circumference of the first carrier block 15A via a bearing 35B. The center gear 30 rotates around the rotation center axis c1.

Furthermore, at the end portion on the base flange 14a side of the first carrier block 15A, a plurality of (three) recesses 28 are formed corresponding to the positions of the aforementioned plurality of (three) crankshafts 18. Each recess 28 is open on the inner peripheral surface side of the first carrier block 15A. Furthermore, at the end portion on the base flange 14a side of each crankshaft 18, a crankshaft gear 31 for transmitting rotation to the crankshaft 18 is installed. The crankshaft gear 31 installed on each crankshaft 18 is arranged on the inner side of the corresponding recess 28. Each crankshaft gear 31 has an external tooth 31a. The outer teeth 31a of each crankshaft gear 31 engage with the area of the other end of the outer teeth 30a of the central gear 30 in the axial direction. 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 speed reducer 10 of this embodiment, the speed reduction is performed by using the front-stage speed reduction section composed of the input gear 33 and the center gear 30, and the rear-stage speed reduction section composed of the crankshaft 18, the first and second rotating gears 19A, 19B, the outer cylinder 17, etc.

In addition, a recessed portion 36 for accommodating the outer gear 33a of the input gear 33 and the intermediate gear 32 is formed at the end of the base flange 14a near the first carrier block 15A. A mounting base 38 for supporting the intermediate gear 32 is installed on the bottom surface of the recessed portion 36 of the base flange 14a (the surface opposite to the end surface of the first carrier block 15A). In addition, a portion of the recessed portion 36 is open to the through hole 25 in the center of the base flange 14a. The intermediate gear 32 disposed in the recessed portion 36 engages with the outer gear 30a of the center gear 30 through the radially inward opening of the recessed portion 36.

The intermediate gear 32 is rotatably supported on a cylindrical support shaft 39. The support shaft 39 is integrally formed on a cylindrical retaining member 40 having an outer diameter larger than that of the support shaft 39 and a shorter shaft length. The support shaft 39 is integrally formed at a position offset from the axis c2 of the retaining member 40.

That is, the support shaft 39 is arranged eccentrically (displaced in the radial direction) relative to the axis c2 of the retaining member 40. The axis c3 of the support shaft 39 is set parallel to the axis c2 of the retaining member 40.

In this embodiment, the position of the axis c2 is set as the reference position on the retaining member 40, and the portion 40a on the retaining member 40 connected to the support shaft 39 is set as the retaining portion of the support shaft 39. The retaining portion of the support shaft 39 is arranged at a position separated from the reference position, i.e., the position of the axis c2.

The mounting base 38 mounted inside the recessed portion 36 is formed with a circular retaining hole 41 for the outer peripheral surface of the retaining member 40 to be fitted and fixed. In the case of this embodiment, the position of the support shaft 39 of the intermediate gear 32 on the base flange 14a (base block 11) can be changed by changing the rotation position of the retaining member 40 relative to the retaining hole 41 around the axis c2. The support shaft 39 of the intermediate gear 32 changes its position when, for example, the number of teeth and the outer diameter of the input gear 33 are changed in order to change the reduction ratio of the reducer 10.

In addition, in the case of this embodiment, the mounting base 38, the fixing block 14 and the first carrier block 15A together constitute a support block for the input gear 33 to be rotatably supported, the central gear 30 (output gear), and the intermediate gear 32. In addition, in this embodiment, the retaining hole 41 of the mounting base 38 and the outer peripheral surface of the retaining member 40 engaged in the retaining hole 41 constitute a rotational position changing portion.

When the number of teeth and outer diameter of the input gear 33 are changed, the distance between the tooth surfaces of the outer teeth 33a of the input gear 33 and the outer teeth 30a of the central gear 30 (output gear) changes, so the intermediate gear 32 cannot be properly engaged with the input gear 33 and the central gear 30 at the previous position of the support shaft 39.

In this case, by appropriately changing the position of the support shaft 39, the intermediate gear 32 can be securely engaged with the input gear 33 and the center gear 30.

FIG6 is a cross-sectional view of the speed reducer 10 similar to FIG5 when the input gear 33 is replaced with a gear of a smaller diameter.

In the example shown in FIG5 , the axis c3 of the support shaft 39 of the intermediate gear 32 is greatly separated from the straight line L1 connecting the tooth surfaces of the input gear 33 (A) and 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 relative to the axis c2 of the retaining member 40.

As shown in the example of FIG. 6, if the outer diameter of the input gear 33 (B) is reduced, the distance between the tooth surfaces of the input gear 33 (B) and the center gear 30 is expanded, and the intermediate gear 32 cannot be reliably engaged with the input gear 33 and the center gear 30 at the position of the support shaft 39 shown in FIG. 5. In this case, the retaining member 40 is removed from the retaining hole 41, and the retaining member 40 is rotated 180° around the axis c2 and is again engaged with the retaining hole 41. Thereby, the axis c3 of the support shaft 39 is eccentric with respect to the axis c2 of the retaining member 40 toward the side closest to the straight line L1 connecting the tooth surfaces of the input gear 33 (B) and the center gear 30 with the shortest distance. As a result, the intermediate gear 32, the input gear 33 and the center gear 30 (B) can be securely engaged.

In addition, in this embodiment, the retaining portion (the portion 40a connected to the support shaft) disposed separately from the axis c2 (reference position) on the retaining member, the rotational position changing portion, i.e., the retaining hole 41, and the outer peripheral surface of the retaining member 40 constitute a gear position changing mechanism (axis position changing portion).

As described above, the retaining member 40 of the support shaft 39 for retaining the intermediate gear 32 of the speed reducer 10 of this embodiment and the support block, i.e., the mounting base 38, constitute a gear position changing mechanism that can change the position of the intermediate gear 32. Therefore, when the input gear 33 is replaced with another gear having a different number of teeth and outer diameter, the position of the intermediate gear 32 can be changed by the gear position changing mechanism in accordance with the change in the distance between the gear surfaces between the input gear 33 and the center gear 30 (output gear).

Therefore, the speed reduction ratio between the input gear 33 and the central gear 30 (output gear) can be changed without replacing the support block such as the fixed block 14. Therefore, when the speed reducer 10 of this embodiment is adopted, the speed ratio between the input gear 33 and the central gear 30 (output gear) can be changed without large-scale parts replacement, and the increase in parts cost can be suppressed.

In addition, the speed reducer 10 of this embodiment is provided with a retaining portion of the support shaft 39 (a portion 40a connected to the support shaft 39) at a position separated from the reference position (axis c2) on the retaining member 40. In addition, a rotation position changing portion (a fitting structure between the retaining member 40 and the retaining hole 41) is provided between the retaining member 40 and the support block, i.e., the mounting base 38, which can change the rotation position of the retaining member 40. Therefore, in the case of adopting the speed reducer 10 of this embodiment, the position of the intermediate gear 32 can be easily changed by simply changing the rotation position of the retaining member 40.

In particular, in the present embodiment, the retaining member 40 is formed in a cylindrical shape, and a retaining hole 41 for the retaining member 40 to be engaged is formed in the support block, i.e., the mounting base 38. Moreover, the outer peripheral surface of the retaining member 40 and the retaining hole 41 of the mounting base 38 constitute a rotation position changing portion. Therefore, when the retaining member 40 is engaged in the retaining hole 41, the position of the intermediate gear 32 can be easily changed by simply changing the rotation angle of the retaining member 40.

In addition, in this embodiment, although the retaining member 40 is formed into a cylindrical shape, the outer peripheral surface of the retaining member 40 may be a shape other than a circle, such as a polygonal shape such as a square.

Furthermore, in the speed reducer 10 of this embodiment, since the support shaft 39 of the intermediate gear 32 and the retaining member 40 are formed integrally, the number of components can be reduced, thereby reducing costs.

However, the support shaft 39 may be formed as a separate component from the retaining member 40, and the support shaft 39 may be fixed relative to the retaining member 40 by pressing, etc.

(Variation example)

In the above-mentioned embodiment, the retaining member 40 is detachably mounted in the retaining hole 41 of the mounting base 38. When the input gear 33 is replaced with a member having a different outer diameter, the retaining member 40 is rotated 180° and fixed to the retaining hole 41 again in an engaged state. In contrast, a structure can be adopted in which the mounting base 38 shown in Figures 5 and 6 is mounted in a state rotated 180° around the axis c3 relative to the base flange 14a (support block). Specifically, for example, this can be achieved by configuring the left and right fastening fixing parts 50 of the mounting base 38 in the figure to be left-right symmetrical.

In this case, since the retaining member 40 does not need to be removed from the mounting base 38, the mounting base 38 can be provided as an integral structure with the retaining member 40. In this variation, the mounting base 38 becomes a part of the retaining member that retains the support shaft 39, rather than a part of the support block.

(Second implementation form)

FIG. 7 is a cross-sectional view of the speed reducer 110 of the second embodiment corresponding to a portion of FIG. 5 , and FIG. 8 is a cross-sectional view of the speed reducer 110 of the second embodiment corresponding to a portion of FIG. 6 .

The speed reducer 110 of this embodiment differs from the first embodiment only in the structure of the fitting portion between the retaining member 40A and the mounting base 38A. The retaining member 40A is provided with a pair of chamfered portions 40Aa parallel to each other on the cylindrical outer peripheral surface. The pair of chamfered portions 40Aa are formed symmetrically across the axis c3 of the retaining member 40A. A retaining hole 41A having a shape matching the outer peripheral shape of the retaining member 40A is formed in the mounting base 38A. That is, two planes 41Aa parallel to each other are provided in the retaining hole 41A of the mounting base 38A. The two planes 41Aa are provided for the two chamfered portions 40Aa on the side of the retaining member 40A to abut when the retaining member 40A is fitted into the retaining hole 41A of the mounting base 38A. Therefore, the retaining member 40A is only engaged with the retaining hole 41A at two rotation positions offset by 180° around the axis c2.

The speed reducer 110 of this embodiment can fit the retaining member 40A into the retaining hole 41A at only two rotational positions offset 180° around the axis c2, so the rotational position of the retaining member 40A can be correctly positioned at two positions. Therefore, the tooth surface of the intermediate gear 32 can be correctly engaged with two types of input gears 33 with different numbers of teeth and outer diameters.

(Third implementation form)

FIG9 is a front view of the cross-sectional view of the inner end surface (the end surface opposite to the first carrier block) of the base flange 14a (fixed block 14) of the reducer 210 of the third embodiment.

In FIG. 9 , two types of input gears 33 (A), 33 (B), intermediate gear 32, and center gear 30 (output gear) having different outer diameters and numbers of teeth are indicated by imaginary lines.

The speed reducer 210 of this embodiment is formed with a plurality of support shaft engagement holes 45A and 45B that can engage the support shaft 239 of the intermediate gear 32 with the inner end surface of the base flange 14a. The formation position of each support shaft engagement hole 45A and 45B is set at the position where the tooth surface of the intermediate gear 32 supported by the support shaft 239 engages with the input gear 33 and the center gear 30 used. In addition, in the example shown in FIG. 9, although there are two support shaft engagement holes 45A and 45B, there may be three or more. In addition, in this embodiment, a retaining member for retaining the support shaft 239 is not provided, and the support shaft 239 is formed into a simple cylindrical shape.

In the case of this embodiment, a plurality of support shaft fitting holes 45A, 45B constitute a shaft position changing portion that can change the position of the support shaft 239 of the intermediate gear 32.

When using an input gear 33 (A) with a larger outer diameter, the support shaft 239 is fixed in an engagement state to the support shaft engagement hole 45A far from the straight line L1 connecting the tooth surfaces of the input gear 33 (A) and the center gear 30 with the shortest distance. When the input gear 33 (A) is replaced with another input gear 33 (B) with a smaller outer diameter, after removing the support shaft 239 from the support shaft engagement hole 45A, the support shaft 239 is fixed in an engagement state to the support shaft engagement hole 45B close to the straight line L1 connecting the tooth surfaces of the input gear 33 (B) and the center gear 30 with the shortest distance.

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

In addition, the present invention is not limited to the above-mentioned implementation forms, and various design changes can be made without departing from the scope of the gist.

For example, in the description of the above-mentioned embodiment, a detailed description is given for the case where the input gear is replaced with another gear having a different number of teeth and outer diameter, but when the output gear (e.g., the center gear) is replaced with another gear having a different number of teeth and outer diameter, the position of the support shaft of the intermediate gear can also be changed in the same manner. Moreover, when both the input gear and the output gear are replaced with another different gear, the position of the support shaft of the intermediate gear can also be changed in the same manner.

Furthermore, in the above-mentioned embodiment, although the intermediate gear and the input gear are rotatably supported on the side of the fixed block, it is feasible that the intermediate gear and the input gear are rotatably supported on the side of the first carrier block.

(Fourth implementation form)

The following is a description of the fourth embodiment of the gear mechanism and speed reducer of the present invention based on the drawings.

FIG10 is a cross-sectional view showing the gear mechanism and the speed reducer of this embodiment, and FIG11 is a cross-sectional view along the XI-XI line of FIG10. In the figure, symbol 301 is the speed reducer.

The speed reducer 301 of this embodiment is shown in Figures 10 and 11. The rotational driving force of the motor (rotational driving source) 310 is transmitted to the speed reducer (output unit) 330 via the gear mechanism 320, and is output as the rotational force around the output axis T0 of the speed reducer 330 at a specific speed reduction ratio.

In addition, there is a case where the direction along the output axis T0 is called the up-down direction (vertical direction). The speed reducer 301 of this embodiment can be applied to, for example, the stage drive of a turntable.

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

When viewed along the output axis T0, the motor 310 and the gear mechanism 320 are arranged adjacent to each other. Similarly, when viewed along the output axis T0, the gear mechanism 320 and the speed reducer 330 are arranged adjacent to each other. The positions of the motor 310 and the speed reducer 330 along the output axis T0 are roughly the same. Although the position of the gear mechanism 320 along the output axis T0 is roughly the same as that of the motor 310 and the speed reducer 330, it is arranged at a position slightly adjacent to the lower side.

The gear mechanism 320 includes: a center gear (third gear) 322, which rotates about the center axis T2; an idler gear (second gear) 323, which engages with the center gear 322; and an input gear (first gear) 321, which engages with the idler gear 323 and receives the driving force from the motor 310 from the input shaft 311. The center gear 322, the idler gear 323, and the input gear 321 are all flat 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 is consistent with the output axis T0.

The center gear 322 rotates around the center axis T2. The idler gear 323 rotates around the idler axis T3. The input gear 321 rotates around the input axis T1.

The outer shell 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. When viewed in the direction along the output axis T0, the first block 302b accommodating the gear mechanism 320 and the cylindrical second block 302c accommodating the speed reducer 330 are arranged in an array on the upper surface of the base portion 302a.

The base portion 302a is formed as a support block that at least supports the input gear 321, the center gear 322, and the idler gear 323 in a rotatable manner.

The first block 302b and the second block 302c are respectively coupled to the upper surface of the base portion 302a in an arranged state. The first block 302b and the second block 302c protrude upward from the upper surface of the base portion 302a. The first block 302b and the base portion 302a can be coupled to each other to seal the interior of the reducer 301.

The cylindrical second block 302c is arranged in such a way that its central axis is consistent 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 reducer 301. The second block 302c is fastened to the upper surface of the base 302a by bolts 302j and the like. The second block 302c and the base 302a can be combined with each other to seal the interior of the reducer 301.

The base portion 302a has: a plate-shaped first base portion 302a1, and a plate-shaped second base portion 302a2 having a smaller outline than the first base portion 302a1. The first base portion 302a1 has an outline that can mount both the first block 302b and the second block 302c. The second base portion 302a2 has an outline corresponding to the first block 302b, and as described later, is integrally embedded in the first base portion 302a1 in the area corresponding to the first block 302b. The first base portion 302a1 and the second base portion 302a2 can seal the internal space 328b of the reducer 301.

The first base portion 302a1 is formed to have a thickness greater than that of the second base portion 302a2 so that the second base portion 302a2 can be embedded as described later. The second base portion 302a2 is exposed on the lower surface of the speed reducer 301. The second base portion 302a2 is integrally connected to the first base portion 302a1 at a position opposite to the first block 302b in the vertical direction.

The first block 302b has: a first block side portion 302b1 integrally bonded to the upper surface of the first base portion 302a1, and a first block plate 302b2 integrally bonded to the upper surface of the first block side portion 302b1.

The first block side portion 302b1 protrudes upward from the upper surface of the plate-shaped first base portion 302a1. The first block plate 302b2 is combined in a manner to seal the interior 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 front end of the input shaft 311 that transmits the rotational driving force of the motor 310 to the gear mechanism 320 passes 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 of the first block side 302b1. The front end of the drive shaft 310a is set as an input shaft 311 that passes through the outer shell 302.

A press-fit hole 311a is formed on the outer end surface of the input shaft 311 for inserting the drive shaft 310a of the motor 310. The motor 310 is fixed to the motor support member 326 mounted on 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 with the drive axis T10 extending in the horizontal direction (in a direction parallel to the base 302a). The motor 310 is located slightly above the upper outer surface of the base 302a (on the first block 302b side).

A drive side gear 311b is installed at the front end of the input shaft 311.

The driving side gear 311b is a structure in which teeth are formed at the outer end of a disc-shaped portion protruding radially from the outer circumferential surface of the input shaft 311. The driven side gear 311c is engaged with the driving side gear 311b. The driving side gear 311b and the driven side gear 311c include bevel gears.

In addition, the driving side gear 311b and the driven side gear 311c are not limited to bevel gears, and the following structure can be adopted, that is, the driving axis T10 of the driving side gear 311b and the input axis T1 of the input shaft 321a of the driven side gear 311c are in a cross position relationship, and the driving force can be transmitted from the driving side gear 311b to the driven side gear 311c. The driven side gear 311c uses the input shaft 321a extending in the vertical direction as a rotation axis. 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 includes a shaft member extending in a straight line concentrically with the rotation axis of the driven side gear 311c. The input shaft 321a is supported by a bearing 321g described later in a position where the input shaft T1 is orthogonal to the drive shaft T10 of the input shaft 311. That is, the input shaft 321a is rotatably supported by the housing 302.

In this embodiment, the driving axis T10 of the input shaft 311 is parallel to the upper surface of the reducer 301, and the input axis T1 of the input shaft 321a is orthogonal to the upper surface of the reducer 301.

In addition, the input axis T1 of the input axis 321a and the drive axis T10 of the input axis 311 are not limited to an orthogonal positional relationship, as long as they are a positional relationship other than parallel. For example, the drive axis T10 of the input axis 311 may be tilted in the vertical direction in such a way that the motor 310 side is lowered from the horizontal position.

The driven side gear 311c is a structure in which teeth are formed at the outer end of a disc-shaped portion radially protruding from the outer circumferential surface of the input shaft 321a. The outer end of the driven side gear 311c enters the expanded diameter portion 328d1 formed in the first block 302b. The expanded diameter portion 328d1 is formed at the upper end position of the internal space 328d of the first block side portion 302b1 as described later, and is closed by the first block plate 302b2.

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

Two through holes 328a and 328d2 are formed in the first base portion 302a1 and are connected in the up-down direction. Both the through holes 328a and 328d2 are connected to the internal space 328b.

The through hole 328a is arranged with the output axis T0 as the center line, and is formed into a shape concentric with the cylindrical 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 connects the internal space 328b to the internal space 328d of the first block 302b described later.

The input gear (first gear) 321, the idler gear (second gear) 323, and the center gear (third gear) 322 of the gear mechanism 320 are accommodated in the internal space 328b in a mutually engaged state. The internal space 328b has a planar contour shape that is continuous with a portion that is formed to be concentric with the input shaft (support shaft) 321a, a portion that is formed to be concentric with the idler shaft (support shaft) 323a, and a portion that is concentric with the center gear 322.

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

The center gear 322 is set to have a larger diameter than the input gear 321 and a larger number of teeth than the input gear 321. Therefore, the rotation of the input gear 321 caused by the motor 310 is reduced at a specific reduction ratio and is transmitted to the center gear 322 in this state.

An opening 328b1 is formed in the first base portion 302a1 at the lower side opposite to the input gear 321 and the idle gear 323 of the internal space 328b. The opening 328b1 is closed by inserting the second base portion 302a2 from the lower side. The second base portion 302a2 is fixed at a position halfway into the internal space 328b in the vertical direction.

In the first base portion 302a1, an expanded diameter portion 328b2 having a step difference is formed at the edge of the opening 328b1 of the inner space 328b facing downward. A flange portion 302a2a formed in a manner of protruding toward the periphery of the second base portion 302a2 is embedded in the expanded diameter portion 328b2. In this state, the surfaces of the expanded diameter portion 328b2 and the flange portion 302a2a facing each other in the vertical direction are in contact with each other. Thereby, the position of the second base portion 302a2 relative to the first base portion 302a1 in the vertical direction is fixed. In addition, the expanded diameter portion 328b2 can be formed to the end portion that becomes the outline of the first base portion 302a1 in the horizontal direction. A sealing mechanism such as an O-ring may also be provided around the opening 328b1 at a position above the flange portion 302a2a.

In the second base portion 302a2, a support hole 321f having a circular cross section and a bottom is formed on the inner surface of the inner space 328b.

Bearing 321g is installed in the support hole 321f. Bearing 321g is installed on the inner circumference of the support hole 321f. Bearing 321g supports the lower end of the input shaft 321a. The input shaft 321a has an input axis T1 along the upper and lower directions of the output axis T0. The lower end of the input shaft 321a is inserted into the support hole 321f. The input gear 321 is installed near the lower end of the input shaft 321a.

FIG12 is an explanatory diagram showing the axis position changing portion of this embodiment, and FIG13 is a cross-sectional view along the XIII-XIII line of FIG12 .

In the second base portion 302a2, support holes (support hole portions) 351A, 351C, and 351E with a circular cross section and a bottom are formed on the inner surface of the inner space 328b.

In the first base portion 302a1, support holes (support hole portions) 351B, 351D, and 351F having a circular cross section and a bottom are formed on the inner surface of the inner space 328b.

That is, the base portion 302a has a first base portion 302a1 and a second base portion 302a2 that are axially opposite to the idler gear 323 and located on both sides of the idler gear 323. In addition, support holes (support hole portions) 351A to 351F are formed on the facing surface of at least one of the first base portion 302a1 and the second base portion 302a2.

The support holes (support hole portions) 351A to 351F are provided as shaft position changing portions 350 that can change the position of the idler shaft (support shaft) 323a of the idler gear 323 corresponding to the input gear 321 having different numbers of teeth. The support holes (support hole portions) 351A to 351F are all open relative to the internal space 328b. The support holes (support hole portions) 351A to 351F are all arranged along a circumference R50 located at a specific distance from the rotation center of the input gear 321, i.e., the input axis T1.

The supporting holes (supporting hole portions) 351A to 351F are alternately arranged on the first base portion 302a1 and the second base portion 302a2 on the circumference R50. The supporting holes (supporting hole portions) 351A to 351F are arranged separately from each other on the circumference R50.

The front end of the cylindrical idler shaft 323a is inserted into any of the support holes 351A~351F. Thus, the idler shaft 323a is supported rotatably at one of the support holes 351A~351F where the idler shaft 323a is inserted. The idler gear 323 is connected to the idler shaft 323a.

By selecting the insertion position of the idler shaft 323a through the self-supporting holes 351A~351F, the idler gear 323 is supported in a rotatable manner. The idler shaft 323a has an idler axis T3 along the upper and lower directions of the output axis T0.

The support holes (support hole portions) 351A to 351F and the support hole 321f are formed evenly and separately in a plane observed along the direction of the output axis T0. Moreover, 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.

In addition, FIG. 10 shows the state where the idle shaft 323a of the idle gear 323 is installed in the support hole (support hole portion) 351B among the support holes (support hole portions) 351A to 351F.

Here, the front end of the cylindrical idle shaft 323a is inserted into the support hole 351B. The idle shaft 323a is connected to the idle gear 323.

An internal space 328d extending in the vertical direction is formed at a position opposite to the support hole 321f on the side portion 302b1 of the first block. The internal space 328d is formed by extending in the upward direction, and its lower end is connected to the internal space 328b via the through hole 328d2.

The inner space 328d is set to be circular in cross section corresponding to the through hole 328d2. The upper end of the inner space 328d is closed by the first block plate 302b2. A support hole 321h with a circular cross section and a bottom is formed on the lower surface position of the first block plate 302b2 which becomes the inner side of the inner space 328d. A bearing 321g is installed in the support hole 321h. The bearing 321g is installed on the inner circumference 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 expanded diameter portion 328d1 is formed at the upper end of the internal space 328d. In the expanded diameter portion 328d1, the driven side gear 311c is accommodated at a position that becomes the lower side of the bearing 321g. The lower end of the first block plate 302b2 is embedded in the upper end of the internal space 328d. Around the upper end of the first block plate 302b2, a flange portion 302b2a is provided to protrude radially outward. The flange portion 302b2a contacts the upper end of the first block side portion 302b1, thereby fixing the upper and lower positions of the first block plate 302b2 relative to the first block side portion 302b1. At the same time, the first block side 302b1 is in close contact with the first block plate 302b2, thereby sealing the internal space 328d. A sealing mechanism (sealing structure, sealing component) such as an O-ring can also be provided on the outer peripheral surface of the first block plate 302b2, at a position lower than the flange 302b2a and inserted into the first block side 302b1.

In the first block 302b, a bearing 321g is installed near the lower end of the internal space 328d to support the axial center position of the input shaft 321a. The bearing 321g is installed on the inner circumference of the internal space 328d of the first block side 302b1.

At the lower end of the first block side portion 302b1, which becomes the lower end position of the internal space 328d, a protrusion 302b4 protruding downward is formed at a position around the through hole 328d2. The protrusion 302b4 is inserted into the through hole 328d2 and is used to position 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 expanded diameter portion 328d1 in the up-down direction and at the lower side thereof.

The through hole 328d4 is formed to extend from the input shaft 321a toward the motor 310. The driving side gear 311b is accommodated inside the through hole 328d4. On the outside of the through hole 328d4, at a position surrounding the input shaft 311, the input shaft support portion 325 is connected to the first block side portion 302b1. The input shaft support portion 325 is configured to be cylindrical surrounding the input shaft 311, and a bearing 324 is arranged on the inner side thereof. The bearing 324 supports the input shaft 311 in a rotatable manner. A motor support member 326 is fixed to the outside of the input shaft support portion 325 near the motor 310. The inner part of the input shaft support part 325 has a diameter size corresponding to the through hole 328d4. The input shaft support part 325 and the first block side part 302b1 accommodate the input shaft 311 and the drive side gear 311b, and are sealed relative to the outside.

In the first base portion 302a1, an opening 328b3 is formed on the upper side of the inner space 328b opposite to the center gear 322. The opening 328b3 is closed by the second block 302c and the deceleration portion 330. The opening 328b3 is formed in a planar contour shape that is concentric with the second block 302c and the center gear 322, with the output axis T0 as the center.

In the inner space 328b, the center gear 322 is rotatably supported on the cylinder 334.

The cylinder 334 penetrates the internal space 328b in the vertical direction. The cylinder 334 is arranged with the output axis T0 as the center. The cylinder 334 penetrates the reducer 301 in the vertical direction. The lower end of the cylinder 334 is embedded in the through hole 328a. A sealing member 334b can be provided between the lower end of the cylinder 334 and the inner surface of the through hole 328a. A flange portion 334a exposed on the upper surface of the reducer 330 is formed at the upper end of the cylinder 334. The flange portion 334a is formed to be concave downward relative to the upper surface of the reducer 301. The cylinder 334 is arranged at the approximate 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 is set to a small diameter. The center gear 322 and the gear 322d can rotate integrally around the cylinder 334. The gear 322d is arranged on the upper side of the center gear 322. The gear 322d is arranged closer to the speed reduction unit 330 than the center gear 322. The gear 322d is set on the input side of the speed reduction unit 330. The gear 322d is accommodated inside the opening 328b3. The lower end of the center gear 322 is rotatably supported at a position near the through hole 328a via the bearing 334c. The upper end of the center gear 322 is rotatably supported relative to the speed reduction unit 330 via the bearing 334c.

The deceleration unit 330 is housed in the cylindrical second block 302c fixed to the first base portion 302a1. The deceleration unit 330 may be, for example, an eccentric swing type deceleration mechanism. The deceleration unit 330 has: a carrier 333 disposed on the inner side of the second block 302c, and a transmission shaft 331 that rotates with the rotation of the center gear 322.

The carrier 333 can rotate relative to the second block 302c with the output axis T0 as the center. Specifically, the relative rotation of the second block 302c and the carrier 333 is allowed by the bearing 336 provided between the inner periphery of the second block 302c and the outer periphery of the carrier 333. The carrier 333 is exposed on the upper surface of the deceleration part 330. The carrier 333 becomes the output side of the deceleration part 330. The lower end of the deceleration part 330 is opposite to the opening 328b3. The cylinder 334 passes through the central part of the carrier 333. The axis of the carrier 333 is consistent with the axis of the cylinder 334, that is, the output axis T0. The cylinder 334 can be fixed to, for example, the carrier 333.

The transmission shaft 331 is provided as the input side of the speed reducer 330 to which the rotational driving force is transmitted from the center gear 322. The transmission shaft 331 is rotatably installed relative to the carrier 333 with the direction parallel to the output axis T0 as the axis. Based on the rotation of the transmission shaft 331, the speed reducer 330 rotates the second block 302c and the carrier 333 relative to each other at a speed slower than the rotation speed of the transmission shaft 331. The transmission shaft 331 is provided with a transmission gear 332 engaged with the gear 322d. The transmission gear 332 is a flat gear. The transmission gear 332 is arranged above the center gear 322.

The speed reducer 301 of this embodiment can be fixed on a flat speed reducer mounting surface. Moreover, in this state, a turntable or the like can 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 tightening bolts or the like.

In this speed reducer 301, when the motor 310 is driven, the drive shaft 310a rotates, and the input shaft 311 which is coaxial with and integral with the drive shaft 310a rotates. As a result, the driven side gear 311c engaged 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 axis T1. When the input shaft 321a rotates, the input gear 321 coupled to the input shaft 321a rotates around the input axis T1. The input gear 321 rotates, and the idler gear 323 engaged with the input gear 321 rotates around the idler shaft 323a. If the idler gear 323 rotates, the center gear 322 engaged with the idler gear 323 rotates around the output axis T0. If the center gear 322 rotates, the coaxial gear 322d provided as a whole with the center gear 322 rotates. Thereby, the transmission gear 332 engaged with the gear 322d rotates, and the transmission shaft 331 provided as a whole with the transmission gear 332 rotates. By the rotation of the transmission shaft 331, the second block 302c, which becomes the outer cylinder of the deceleration part 330, and the carrier 333 rotate relative to each other at a speed slower than the rotation speed of the transmission shaft 331. In this way, the turntable rotates.

In the speed reducer 301 of this embodiment, different speed ratios can be selected and set by selecting a plurality of input gears 321 and making the installation position of the idler gear 323 correspond by the shaft position changing unit 350.

In FIG. 12 and FIG. 13, six supporting holes (supporting hole portions) 351A to 351F are shown as the shaft position changing portion 350, wherein the idle shaft 323a of the idle gear 323 is inserted into the supporting hole 351A.

When viewed along the direction of the input axis T1, the support hole 351F is arranged in such a way that the idle axis T3 becomes a straight line connecting the input axis T1 and the center axis T2.

Furthermore, when viewed along the direction of the input axis T1, the support holes 351A to 351E are arranged in order from near to far, namely, support hole 351E, support hole 351D, support hole 351C, support hole 351B, and support hole 351A, in a manner that the distance from the straight line connecting the input axis T1 and the center axis T2 increases. Among the support holes 351A to 351F, support hole 351A is the farthest from the straight line connecting the input axis T1 and the center axis T2.

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

In contrast, as shown by the imaginary lines in FIG. 12 and FIG. 13, when the input gear 321 (D) having a smaller outer diameter and a smaller number of teeth than the input gear 321 (A) is used, the idler gear 323 inserts the idler shaft 323a into the support hole 351D. The idler gear 323 is mounted on the second base portion 302a2 of the base portion 302a using the support hole 351D.

Similarly, by using any of the support holes 351A~351F to mount the idler gear 323 on the base portion 302a, it can correspond to the input gear 321 with different outer diameters and numbers of teeth.

In the speed reducer 301 of this embodiment, when the input gear 321 having a different outer diameter and number of teeth is replaced, the idler shaft 323a of the idler gear 323 can be fixed at the best position by appropriately selecting from the plurality of support holes 351A to 351F formed in the base portion 302a as the shaft position changing portion 350 corresponding to the change in the distance between the tooth surfaces of the input gear 321 and the center gear 322.

Therefore, the speed reduction ratio between the input gear 321 and the center gear 322 can be changed without replacing the support block such as the base 302a, and the change range can be further expanded. Thus, when the speed reducer 301 of this embodiment is adopted, the change range of the speed ratio between the input gear 321 and the center gear 322 can be expanded without large-scale parts replacement, and the increase in parts cost can be suppressed.

Furthermore, by arranging a plurality of supporting holes 351A~351F along the circumference R50, the range of change of the speed ratio between the input gear 321 and the center gear 322 can be expanded by simply changing the mounting position of the idler gear 323 relative to the input gears 321(A)~(F) having different outer diameters and numbers of teeth, and the increase in parts cost can be suppressed.

A plurality of supporting holes 351A to 351F are alternately arranged on the first base portion 302a1 and the second base portion 302a2 on the circumference R50. In this way, compared with the case where a plurality of supporting holes 351A to 351F are arranged on only one side of the first base portion 302a1 and the second base portion 302a2, it is possible to respond to a slight change in the speed ratio. Moreover, even in the case of responding to a slight change in the speed ratio, the distance between adjacent supporting holes 351A to 351F can be set within a range with sufficient strength on either the first base portion 302a1 or the second base portion 302a2.

In addition, the present invention is not limited to the above-mentioned implementation forms, and various design changes can be made within the scope of the gist.

For example, although the support holes 351A to 351F are shown as being arranged at 6 locations in the above-mentioned embodiment, this is not limited to this. Furthermore, although the support holes 351A to 351F are arranged alternately in the first base portion 302a1 and the second base portion 302a2, this is not limited to this. As the shaft position changing portion 350, the arrangement can be appropriately changed in accordance with the set speed ratio of the input gear 321 and the center gear 322.

Furthermore, although in this embodiment, the reducer 301 is placed on a surface extending in the horizontal direction and used to drive the turntable, it is not limited to this structure and use. The reducer 301 in this embodiment can be fixed on a mounting surface extending in a direction other than the horizontal direction.

Furthermore, although the output side of the deceleration unit 330 is described as the carrier 333, it is not limited to this configuration, and any one of the carrier 333 and the cylindrical second block 302c can be set as the output side.

The gear mechanism of the present invention is not limited to the reducer 301 of the above-mentioned embodiment, but can be applied to any machine or device.

10: Speed reducer

14:Fixed block

14a: Base flange

18: Crankshaft

25:Through hole

27: Cylinder

30: Central gear (output gear)

30a,31a,33a: external teeth

31: Crankshaft gear

32: Middle gear

33(A): Input gear

36: Concave part

38: Install the base

39: Support shaft

40: Retaining components

40a: The part connected to the support shaft

41:Holding hole

50: Fastening fixing part

c1: rotation center axis

c2,c3: axis

c4: rotation center axis

L1: Straight line

Claims (12)

A speed reducer, comprising: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; a support shaft supporting the intermediate gear in a manner that allows the intermediate gear to rotatably support the intermediate gear; and a gear position changing mechanism that can change the position of the intermediate gear relative to the input gear and the output gear; and the gear position changing mechanism comprises: a retaining member detachably mounted on the support block; and a retaining portion that is a portion of the retaining member connected to the support shaft; and the outer diameter of the retaining member is larger than the outer diameter of the support shaft. The speed reducer of claim 1, wherein the aforementioned retaining member includes a retaining portion of the aforementioned support shaft at a position separated from the reference position on the retaining member; and the aforementioned retaining member and the aforementioned support block include a rotational position changing portion that can change the rotational position of the aforementioned retaining member centered on the aforementioned reference position; the aforementioned gear position changing mechanism includes: the aforementioned retaining portion of the aforementioned retaining member, and the aforementioned rotational position changing portion. The speed reducer of claim 2, wherein the aforementioned retaining member is formed into a cylindrical shape with the aforementioned reference position as the axis; and the aforementioned support block has a circular retaining hole for the outer peripheral surface of the aforementioned retaining member to fit into; and the aforementioned rotational position changing portion has: the outer peripheral surface of the aforementioned retaining member, and the aforementioned retaining hole. A speed reducer as claimed in claim 3, wherein the aforementioned support shaft is integrally formed in the aforementioned retaining portion of the aforementioned retaining member. A speed reducer comprises: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; a support shaft supporting the intermediate gear in a manner that allows the intermediate gear to rotatably support the intermediate gear; a retaining member detachably mounted on the support block; and a retaining portion, which is a portion of the retaining member connected to the support shaft; and the retaining member The outer diameter is larger than the outer diameter of the aforementioned support shaft; the aforementioned retaining member is formed in a cylindrical shape, and the aforementioned support shaft is integrally formed at a position separated from the axis position of the retaining member; the aforementioned support block has a circular retaining hole for the outer peripheral surface of the aforementioned retaining member to fit into; the outer peripheral surface of the aforementioned retaining member and the aforementioned retaining hole of the aforementioned support block constitute a rotational position changing portion, and the rotational position changing portion can change the rotational position of the aforementioned retaining member with its axis as the center. A speed reducer, comprising: a support block; an input gear rotatably supported by the support block; an intermediate gear engaged with the input gear; an output gear engaged with the intermediate gear; a support shaft supporting the intermediate gear in a manner that allows the intermediate gear to rotatably support the intermediate gear; and an axis position changing portion that can change the position of the support shaft of the intermediate gear; and the axis position changing portion comprises: a retaining member detachably mounted on the support block; and a retaining portion that is a portion of the retaining member connected to the support shaft; and the outer diameter of the retaining member is larger than the outer diameter of the support shaft. As in claim 6, the reducer, wherein the aforementioned support block has a plurality of support shaft engagement holes for the aforementioned support shaft to engage with; and the aforementioned shaft position changing portion is further provided with the aforementioned plurality of support shaft engagement holes. A gear mechanism, comprising: a support block; a first gear rotatably supported by the support block; a second gear engaged with the first gear; a third gear engaged with the second gear; and an axis position changing portion, which can change the position of the support shaft of the second gear corresponding to the third gear having a different number of teeth; and the axis position changing portion includes a plurality of support holes, which can support the support shaft inserted therein in a rotatable manner and are separately formed in the support block; The support block includes a first base portion and a second base portion that are opposite to each other in the axial direction of the second gear and located on both sides of the second gear; and the supporting hole portion is included on the facing surface of at least one of the first base portion and the second base portion; the support block includes a plurality of the supporting hole portions, and the plurality of the supporting hole portions are arranged along a circumference located at a specific distance from the rotation center of the first gear, and are alternately arranged on the facing surface of the first base portion and the facing surface of the second base portion on the circumference. A gear mechanism as claimed in claim 8, wherein the support block includes a plurality of support holes along a circumference located at a specific distance from the rotation center of the first gear. A speed reducer, comprising: a gear mechanism as described in claim 8 or claim 9; and a speed reduction unit connected to the gear mechanism. A driving device, comprising: a speed reducer as described in any one of claims 1 to 7, which reduces the speed of a rotational driving source and outputs it; and a rotating block connected to the output portion of the speed reducer. A driving device, comprising: a speed reducer as described in claim 10, which reduces the speed of the rotation of a rotary driving source and outputs it; and a rotating block connected to the output portion of the aforementioned speed reducer.