JP2023147420A - Eccentric oscillation type speed reducer - Google Patents

Abstract

To provide a technology capable of suppressing an axial movement amount of an input shaft when a speed reducer is separated from a motor, while reducing the weight of the speed reducer.SOLUTION: An eccentric oscillation type speed reducer comprises an input shaft 26, an eccentric body provided on the input shaft 26, and an external gear 30 that is oscillated by the eccentric body. In the eccentric oscillation type speed reducer, an input shaft bearing supporting the input shaft 26 is not arranged on one side in an axial direction with respect to the external gear 30, but arranged on the other side in the axial direction with respect to the external gear 30. The eccentric oscillation type speed reducer comprises a first regulation member 50A that regulates axial movement with respect to the input shaft 26. At least a portion of the first regulation member 50A overlaps the external gear 30 in the axial direction.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to an eccentric rocking type speed reduction device.

Patent Document 1 discloses an actuator including a motor and an eccentric swing type reduction gear. This eccentric oscillating type speed reducer consists of an input shaft, an eccentric body provided on the input shaft, an external gear that is oscillated by the eccentric body, and an external gear arranged on both sides of the external gear in the axial direction to support the input shaft. and an input shaft bearing. The input shaft bearing is normally regulated from moving in the axial direction away from the external gear by a movement regulating section such as a retaining ring provided on the carrier.

Japanese Patent Application Publication No. 2013-148198

There are cases where it is required to reduce the weight of the reduction gear. As a solution to this problem, the input shaft bearing may be omitted. However, if the input shaft bearing is simply omitted, when the reduction gear is separated from the motor, the input shaft will be allowed to move to the side where the input shaft bearing is not placed, and the amount of axial movement This can lead to an increase in This may cause unintended problems, so improvement is desired.

One of the objects of the present disclosure is to provide a technique that can reduce the weight of the speed reducer and suppress the amount of axial movement of the input shaft when the speed reducer is separated from the motor.

The speed reduction device of the present disclosure is an eccentric swing type speed reduction device including an input shaft, an eccentric body provided on the input shaft, and an external gear rocked by the eccentric body, the external gear An input shaft bearing supporting the input shaft is not disposed on one side in the axial direction relative to the external gear, but is disposed on the other side in the axial direction relative to the external gear, and axial movement with respect to the input shaft is restricted. A first regulating member is provided, and at least a portion of the first regulating member overlaps the external gear in the axial direction.

According to the present disclosure, it is possible to reduce the weight of the speed reduction device and suppress the axial movement of the input shaft when the speed reduction device is separated from the motor.

FIG. 3 is a side sectional view of the actuator of the first embodiment. FIG. 2 is an enlarged view of the speed reduction device of the first embodiment. FIG. 3 is an explanatory diagram regarding the effects of the speed reduction device of the first embodiment. It is another explanatory diagram regarding the effect of the speed reduction device of a 1st embodiment. FIG. 3 is an enlarged view of a speed reduction device according to a second embodiment. It is an enlarged view of the speed reduction device of 3rd Embodiment.

Embodiments will be described below. Identical components are given the same reference numerals and redundant explanations will be omitted. In each drawing, constituent elements are omitted, enlarged, or reduced as appropriate for convenience of explanation. The drawings should be viewed according to the direction of the symbols.

(First Embodiment) Refer to FIG. 1. The actuator 10 includes a motor 12 and a reduction gear 14.

Specific examples of the motor 12 are not particularly limited, and may be, for example, a permanent magnet motor, an induction motor, a reluctance motor, a coreless motor, or the like. The motor 12 includes a motor shaft 16, a stator 18 and a rotor 20 that generate a rotating magnetic field that rotates the motor shaft 16, and a motor casing 22 that houses the stator 18 and rotor 20. Stator 18 is fixed to motor casing 22 and rotor 20 is fixed to motor shaft 16. The motor casing 22 includes a cylindrical motor frame 22a and a pair of covers 22b that cover the stator 18 and rotor 20 from both sides in the axial direction. Motor shaft bearings 24A and 24B that rotatably support the motor shaft 16 are incorporated into the pair of covers 22b. The motor shaft bearings 24A and 24B include a first motor shaft bearing 24A on the input side (counter-load side) with respect to the stator 18 and rotor 20, and a second motor shaft bearing 24A on the counter-input side (load side) with respect to them. bearing 24B.

The speed reducer 14 meshes with an input shaft 26 into which the rotation of the motor shaft 16 is input, an eccentric body 28 provided on the input shaft 26, an external gear 30 that is oscillated by the eccentric body 28, and the external gear 30. It includes an internal gear 32 and an output member 34 that outputs the output rotation transmitted from the gear mechanism constituted by the external gear 30 and the internal gear 32 to a driven member. In addition, the speed reduction device 14 includes an eccentric bearing 36 disposed between the eccentric body 28 and the external gear 30, and carriers 38A and 38B disposed laterally in the axial direction with respect to the external gear 30. It includes a reduction gear casing 40 that accommodates the external gear 30 and carriers 38A and 38B, and an inner pin 42 that protrudes from the carrier 38A. The driven member is, for example, a part of a driven machine such as a conveyor, a wheel, a machine tool, or a robot.

Hereinafter, the direction along the rotation center C26 of the input shaft 26 will be referred to as the axial direction X, and the radial direction and circumferential direction of a circle concentric with the rotation center C26 will be simply referred to as the radial direction and the circumferential direction. Further, the side on which the motor 12 is located in the axial direction X is referred to as an input side, and the side opposite to the input side in the axial direction X is referred to as an anti-input side. Further, the side where the external gear 30 is located in the axial direction X is referred to as the external gear side, and the side opposite to the external gear 30 in the axial direction X is referred to as the anti-external gear side. Further, a state in which the speed reduction device 14 is separated from the motor 12 (see FIG. 3, etc.) is referred to as a separated state, and a state in which the speed reduction device 14 is assembled to the motor 12 (see FIG. 1, etc.) is referred to as an assembled state.

The speed reduction device 14 of this embodiment is an eccentric rocking type speed reduction device, in which one of the external gear 30 and the internal gear 32 (here, the external gear 30) is swung by the input shaft 26 (crankshaft). can transmit output rotation to the output member 34. Although an example in which the carrier 38A serves as the output member 34 will be described here, the reduction gear casing 40 may serve as the output member 34. The speed reduction device 14 of this embodiment is a center crank type in which the input shaft 26 is arranged concentrically with the center C32 of the internal gear 32.

The input shaft 26 is integrated with the motor shaft 16. Rotation is input to the input shaft 26 from the external motor shaft 16 . The input shaft 26 is separate from the motor shaft 16. Although this embodiment shows an example in which rotation is directly input from the motor shaft 16 to the input shaft 26, rotation may be input via another member. When the input shaft 26 is in an assembled state in which the speed reduction device 14 is assembled to the motor 12, the axial movement of the input shaft 26 is regulated by the motor shaft bearings 24A and 24B of the motor 12. In this embodiment, the axial movement of the input shaft 26 toward the input side is achieved by the movement restriction portion 16c provided on the motor shaft 16 integrated with the input shaft 26 hitting the first motor shaft bearing 24A from the non-input side. Regulated. The axial movement of the input shaft 26 toward the opposite input side is caused by the rotor 20 fixed to the motor shaft 16 integrated with the input shaft 26 hitting the second motor shaft bearing 24B from the input side via the spacer 21. Regulated. The movement restricting portion 16c of this embodiment is a convex portion that protrudes radially outward at the outer peripheral portion of the motor shaft 16.

The input shaft 26 is a crankshaft that includes at least one (here, three) eccentric bodies 28 . The eccentric body 28 of this embodiment is provided as a part of the same member as the input shaft 26, but may be provided separately from the input shaft 26. The eccentric body 28 is eccentric with respect to the rotation center C26 of the input shaft 26 by an amount of eccentricity e. The eccentric phases of the plurality of eccentric bodies 28 are shifted by 360°/M when the number of eccentric bodies 28 is M (three in this embodiment). The number of eccentric bodies 28 is not particularly limited, and may be one, two, or four or more.

The external gear 30 is provided individually corresponding to each of the plurality of eccentric bodies 28 and is supported by the corresponding eccentric body 28 via an eccentric bearing 36 so as to be relatively rotatable. The external gear 30 includes a shaft hole 30a through which the input shaft 26 passes and in which the eccentric bearing 36 is disposed. The plurality of external gears 30 are in contact with each other at opposing locations facing each other in the axial direction X. The axial movement of the plurality of external gears 30 is regulated by gear regulating members arranged on both sides of the plurality of external gears 30 in the axial direction. The gear regulating member of this embodiment is an outer ring 44a of the main bearing 44, which will be described later. The specific example of the gear regulating member is not particularly limited, and may also be carriers 38A, 38B, etc.

The internal gear 32 is integrated with the reduction gear casing 40. In this embodiment, the speed reducer casing 40 is configured by combining a plurality of casing members 40a and 40b. The casing members 40a and 40b include a first casing member 40a in which the internal gear 32 is provided on the inner periphery, and a first casing member 40a that is provided closer to the motor 12 in the axial direction X than the first casing member 40a and is connected to the motor casing 22. 2 casing member 40b.

The eccentric bearing 36 includes a plurality of rolling elements 36a and a retainer 36b that maintains the relative positions of the plurality of rolling elements 36a. Although the rolling elements 36a of this embodiment are rollers, the specific example thereof is not particularly limited. The eccentric bearing 36 of this embodiment does not include a dedicated outer ring, and the inner peripheral surface of the shaft hole 30a of the external gear 30 also serves as the outer ring. The eccentric bearing 36 of the embodiment does not have a dedicated inner ring, and the outer peripheral surface of the eccentric body 28 also serves as the inner ring. In addition to this, the eccentric bearing 36 may include a dedicated outer ring and an inner ring.

The carriers 38A, 38B include a first carrier 38A disposed on the opposite input side with respect to the external gear 30, and a second carrier 38B disposed on the input side with respect to the external gear 30. A main bearing 44 that connects the reduction gear casing 40 and the carriers 38A, 38B in a relatively rotatable manner is arranged between the reduction gear casing 40 and the carriers 38A, 38B.

A plurality of internal pins 42 are provided at intervals around the center C32 at positions offset from the center C32 of the internal gear 32. The inner pin 42 passes through a pin hole 30b formed in the external gear 30 in the axial direction. The inner pin 42 of this embodiment is configured as a part of the same member as the carrier 38A, but may be configured separately from the carrier 38A. The inner pin 42 of this embodiment connects the first carrier 38A and the second carrier 38B. The inner pin 42 is in contact with the pin hole 30b of the external gear 30, and when the external gear 30 swings, it is possible to synchronize the rotation component of the external gear 30 with the carriers 38A, 38B. . "Synchronized with the rotation component" here means that the rotation component of the external gear 30, the rotation component of the carriers 38A and 38B, and the revolution component of the inner pin 42 are maintained at the same magnitude within a numerical range including zero. Say something. The inner pin 42 of this embodiment is in contact with the pin hole 30b of the external gear 30 via a roller 46 arranged on the outer circumferential side thereof. In addition to this, the internal pin 42 may be in direct contact with the pin hole 30b of the external gear 30.

The operation of the above actuator 10 (deceleration device 14) will be explained. Motor shaft 16 is rotated by a rotating magnetic field generated by stator 18 and rotor 20. The rotation of the motor shaft 16 is input to the input shaft 26 . When the input shaft 26 rotates, the external gear 30 swings by the eccentric body 28 of the input shaft 26 such that the center of the external gear 30 rotates around the rotation center C26 of the input shaft 26. When the external gear 30 swings, the meshing position between the external gear 30 and the internal gear 32 changes around the center of the internal gear 32. Accordingly, each time the input shaft 26 rotates once, one of the external gear 30 and the internal gear 32 (in this case, the external gear 30) rotates by the difference in the number of teeth between the external gear 30 and the internal gear 32. . This rotation component is transmitted as output rotation to the output member 34 (here, the first carrier 38A) via the inner pin 42. At this time, the output rotation that is decelerated relative to the rotation of the input shaft 26 is transmitted to the output member 34.

Here, in the speed reduction device 14 of this embodiment, an input shaft bearing that supports the input shaft 26 is not disposed on one side (here, the input side) in the axial direction X with respect to the external gear 30. Further, in the speed reduction device 14 of the present embodiment, an input shaft bearing that supports the input shaft 26 is not disposed on the other side of the external gear 30 in the axial direction X (here, on the opposite input side). The "input shaft bearing" here refers to one that is disposed between the carriers 38A, 38B and the input shaft 26 and directly supports the input shaft 26.

See FIG. 2. The speed reduction device 14 includes a first regulating member 50A disposed on the other side (the opposite input side) of the external gear 30 in the axial direction ), and shaft fixing members 52A and 52B fixed to the input shaft 26 in the axial direction X.

The regulating members 50A and 50B are plate-shaped members arranged on the radially outer side of the input shaft 26. Although the regulating members 50A and 50B of this embodiment have an annular shape continuous in the circumferential direction, they may have a notched annular shape with a part of the circumferential direction cut away. The outer circumference side portions 50a of the regulation members 50A, 50B are provided at positions shifted toward the external gears from the inner circumference side portions 50b of the regulation members 50A, 50B. The regulating members 50A and 50B are regulated from moving in the axial direction with respect to the input shaft 26, as will be described later.

The shaft fixing members 52A and 52B are arranged such that the first shaft fixing member 52A is disposed on the side opposite to the externally toothed gear with respect to the first regulating member 50A, and the shaft fixing member 52A is disposed on the side opposite to the externally toothed gear with respect to the second regulating member 50B. and a second shaft fixing member 52B. In this embodiment, each of the first shaft fixing member 52A and the second shaft fixing member 52B is a retaining ring. The shaft fixing members 52A and 52B constituted by retaining rings are fixed to the input shaft 26 in the axial direction X by being fitted into the grooves 54 formed in the input shaft 26. The shaft fixing members 52A, 52B regulate the axial movement of the regulating members 50A, 50B located between the external gear 30 and themselves. The shaft fixing members 52A and 52B of this embodiment directly regulate the axial movement of the regulating members 50A and 50B, but they may also regulate it through other members (for example, an input shaft bearing 70, a collar, etc. to be described later). good.

The inner peripheral side portions 50b of the regulating members 50A, 50B are in contact with the shaft fixing members 52A, 52B located on the side opposite to the externally toothed gear with respect to the regulating members 50A, 50B, so that the inner circumferential side portion 50b of the regulating member 50A, 50B is prevented from moving toward the side opposite to the externally toothed gear with respect to the input shaft 26. Axial movement is restricted. In addition, the inner peripheral side portions 50b of the regulating members 50A and 50B are regulated from moving in the axial direction toward the external gear by contacting with the stepped portion 26a provided on the input shaft 26. As a result, the regulating members 50A and 50B are prevented from moving to both sides in the axial direction with respect to the input shaft 26, and are positioned in the axial direction X with respect to the input shaft 26. This requirement is satisfied whether the speed reducer 14 is in the separated state or the assembled state. The stepped portion 26a of the input shaft 26 is disposed on the external gear side with respect to the regulating members 50A and 50B, and its outer diameter increases toward the external gear side.

At least a portion of the regulating members 50A, 50B overlaps in the axial direction X with the external gear 30 adjacent in the axial direction X to the regulating members 50A, 50B. Thereby, as will be described later, when the reduction gear device 14 is in the separated state, by contacting the external gear 30, the axial movement of the regulating members 50A and 50B toward the external gear is regulated. In this embodiment, the entire circumferential direction of the regulating members 50A and 50B overlaps with the external gear 30 in the axial direction X. In addition, a portion of the regulating members 50A, 50B in the circumferential direction may overlap with the external gear 30 in the axial direction X. In this embodiment, this condition is satisfied by each of the outer peripheral side portions 50a of the first regulating member 50A and the second regulating member 50B.

The outer diameter R50 of the regulating members 50A and 50B, the inner diameter R30a of the shaft hole 30a of the external gear 30, and the eccentricity e of the eccentric body 28 are assumed. The outer diameter R50 refers to the distance (radius) from the rotation center C26 of the input shaft 26 to the outer peripheral surfaces of the regulating members 50A and 50B. The inner diameter R30a refers to the distance (radius) from the center C30a of the shaft hole 30a to the inner peripheral surface of the shaft hole 30a. At this time, by making the outer diameter R50 of the regulating members 50A, 50B larger than the difference value (R30a-e) between the inner diameter R30a of the shaft hole 30a and the eccentricity e of the eccentric body 28, the circumferential direction of the regulating members 50A, 50B is At least a portion of the external gear 30 can be overlapped with the external gear 30 in the axial direction X. In addition, by making the outer diameter R50 of the regulating members 50A, 50B larger than the sum (R30a+e) of the inner diameter R30a of the shaft hole 30a and the eccentricity e of the eccentric body 28, the entire circumferential direction of the regulating members 50A, 50B is It can be overlapped with the external gear 30 in the axial direction.

The plurality of eccentric bearings 36 are in contact with each other at opposing locations in the axial direction X. Here, opposing portions of the retainer 36b of the plurality of eccentric bearings 36 are in contact with each other. The first regulating member 50A and the second regulating member 50B are caused by contact between the regulating members 50A, 50B and the eccentric bearings 36 adjacent to each other in the axial direction 36 is restricted from moving in the axial direction. In this embodiment, the outer peripheral side portions 50a of the regulating members 50A, 50B contact the retainer 36b of the eccentric bearing 36, thereby regulating their axial movement. As a result, the axial movement of the plurality of eccentric bearings 36 is restricted by the first restriction member 50A and the second restriction member 50B, and the eccentric bearings 36 are positioned in the axial direction X with respect to the input shaft 26. This requirement is satisfied whether the speed reducer 14 is in the separated state or the assembled state.

The effects of the above reduction gear device 14 will be explained.

(A) In the reduction gear device 14, an input shaft bearing is not arranged on one side (input side) in the axial direction X with respect to the external gear 30. Therefore, by omitting the input shaft bearing, the weight of the speed reducer 14 can be reduced. Further, by omitting the input shaft bearing, friction loss can be reduced, and the transmission efficiency of the speed reducer 14 can be improved.

See FIG. 3. Assuming that the input shaft bearing is not disposed on one side of the external gear 30 in the axial direction X (the input side, the right side in FIG. 3), it is assumed that the first regulating member 50A is not provided. In this case, when the speed reducer 14 is in the separated state, the input shaft 26 is allowed to move largely to the one side where the input shaft bearing is not present. This may cause unintended problems such as the input shaft 26 falling off and the rolling elements 36a of the eccentric bearing 36 being worn out.

(A) Here, in the speed reduction device 14 of this embodiment, the first regulating member 50A is arranged on the other side in the axial direction X (the opposite input side, the left side in FIG. 3) with respect to the external gear 30, The first regulating member 50A overlaps the external gear 30 in the axial direction X. As shown in FIG. 3, consider a case where the input shaft 26 is about to move to one side (the right side in FIG. 3) where the input shaft bearing is not arranged. In this case, the first regulating member 50A comes into contact with the external gear 30, thereby regulating its axial movement toward the external gear. Further, the axial movement of the input shaft 26 is regulated by the first regulating member 50A, which regulates axial movement with respect to the input shaft 26. As a result, the external gear 30 and the first regulating member 50A can regulate the axial movement of the input shaft 26 to one side. Therefore, even if the input shaft bearing is not arranged on one side (input side) in the axial direction The amount of axial movement of the input shaft 26 at certain times can be suppressed.

(B) The first regulating member 50A regulates the axial movement of the eccentric bearing 36. Therefore, when the speed reducer 14 is in the separated state, the first regulating member 50A can prevent the components of the eccentric bearing 36 (such as the rolling elements 36a) from falling off. Similar effects can be obtained by the second regulating member 50B.

(C) The speed reducer 14 includes a first shaft fixing member 52A that is fixed to the input shaft 26 in the axial direction X and regulates the axial movement of the first regulating member 50A. Therefore, when the input shaft 26 attempts to move to one side (input side) in the axial direction 52A makes it possible to restrict movement of the input shaft 26.

(D) The first shaft fixing member 52A is a retaining ring. Therefore, it becomes possible to restrict the axial movement of the first restriction member 50A with respect to the input shaft 26 with a simple configuration.

(E) In the reduction gear device 14, no input shaft bearing is disposed on the other side (counter-input side) of the external gear 30 in the axial direction X. Therefore, by omitting the input shaft bearing, the weight of the reduction gear device 14 can be further reduced. Further, by omitting the input shaft bearing, the transmission efficiency of the speed reducer 14 can be further improved.

See FIG. 4. As in this embodiment, when the second regulating member 50B is not provided on the premise that the input shaft bearing is not arranged on the other side of the external gear 30 in the axial direction X (the opposite input side, the left side in FIG. 4) Assume that In this case, when the speed reducer 14 is in the separated state, a large movement of the input shaft 26 to the side without its input shaft bearing is allowed. Moreover, even when the input shaft bearing 70 is arranged on the other side (counter-input side) of the external gear 30 in the axial direction X, as in a second embodiment described later, The same thing can be said when the carrier 38A is not provided with a movement restriction portion that restricts axial movement toward the gear, and when the second restriction member 50B is not provided.

(F) Here, in the reduction gear device 14, a second regulating member 50B is disposed on one side of the external gear 30 in the axial direction X (input side, right side in FIG. 4), and the second regulating member 50B overlaps the external gear 30 in the axial direction X. As shown in FIG. 4, consider a case where the input shaft 26 is about to move to the other side in the axial direction X (the opposite input side, the left side in FIG. 4). In this case, the second regulating member 50B comes into contact with the external gear 30, thereby regulating its axial movement toward the external gear. Furthermore, the input shaft 26 is restricted from moving in the axial direction toward the other side by the second restricting member 50B, which restricts the movement of the input shaft 26 in the axial direction. As a result, the external gear 30 and the second regulating member 50B can regulate the axial movement of the input shaft 26 to the other side. Therefore, compared to the case where the second regulating member 50B is not provided as described above, the amount of axial movement of the input shaft 26 when the speed reduction device 14 is in the separated state can be suppressed. Furthermore, combined with the effect of the first regulating member 50A, the amount of axial movement of the input shaft 26 can be greatly suppressed.

(G) The speed reducer 14 includes a second shaft fixing member 52B that is fixed to the input shaft 26 in the axial direction X and regulates the axial movement of the second regulating member 50B. Therefore, when the input shaft 26 attempts to move to the other side (counter-input side) in the axial direction become able to.

(H) The second shaft fixing member 52B is a retaining ring. Therefore, it becomes possible to restrict the axial movement of the second restriction member 50B with respect to the input shaft 26 with a simple configuration.

Next, other features of the speed reducer 14 will be explained. See FIG. 2. The input shaft 26 of this embodiment includes a hollow portion 26b, and the motor shaft 16 is inserted into the hollow portion 26b. Input shaft 26 is integrally rotatably connected to motor shaft 16 using connection structure 60 . The connection structure 60 of this embodiment includes a keyway 60a formed in the inner peripheral surface of the hollow portion 26b of the input shaft 26 and the outer peripheral surface of the motor shaft 16, and a key 60b fitted into the keyway 60a. A specific example of the connection structure 60 is not particularly limited. In addition to this, the connection structure 60 may be, for example, a male spline and a female spline that are provided on each of the input shaft 26 and the motor shaft 16 and that fit into each other.

The input shaft 26 is fastened to the motor shaft 16 in the axial direction X by a bolt 62, as described below. The bolt 62 applies an axial force F1 to the input shaft 26 that presses the input shaft 26 against the motor shaft 16. The bolt 62 of this embodiment applies an axial force F1 to the input shaft 26 via the seat member 64 on which the head of the bolt 62 is seated. The seat member 64 is a flanged bush. The seat member 64 includes a cylindrical portion 64a that is inserted into the hollow portion 26b of the input shaft 26 from the non-input side end, and a flange portion 64b that protrudes outward from the non-input side end of the cylindrical portion 64a. The cylindrical portion 64a includes a counterbore hole 64c in which the head portion 62a of the bolt 62 is accommodated, and an insertion hole 64d having an inner diameter smaller than the counterbore hole 64c and into which the shaft portion 62b of the bolt 62 is inserted. The head 62a of the bolt 62 is seated on the bottom of the counterbore hole 64c. The axial force F1 of the bolt 62 is transmitted to the input shaft 26 by screwing the shaft portion 62b of the bolt 62 into the female threaded hole 16a formed at the opposite end of the motor shaft 16. In this embodiment, the axial force F1 of the bolt 62 is transmitted to the input shaft 26 via the flange portion 64b of the seat member 64. The axial force F1 transmitted to the input shaft 26 is received by the stepped portion 16b formed on the motor shaft 16. As a result, the input shaft 26 is pressed against the stepped portion 16b of the motor shaft 16 by the axial force F1 of the bolt 62, thereby being fastened to the motor shaft 16 in the axial direction X. At this time, a frictional resistance corresponding to the axial force F1 acts between the input shaft 26 and the motor shaft 16, and the relative rotation of the input shaft 26 with respect to the motor shaft 16 is regulated by the frictional resistance.

(I) In this way, the input shaft 26 is axially fastened to the motor shaft 16 by the bolt 62. Therefore, when an overturning moment acts on the input shaft 26, the overturning moment can be transmitted from the input shaft 26 to the motor shaft 16 via the bolt 62. In turn, the motor shaft 16 supported by the motor shaft bearing 24 can effectively resist overturning moments acting on the input shaft 26. In particular, even when the input shaft bearing for resisting the overturning moment is omitted, there is an advantage that the overturning moment can be effectively resisted. The overturning moment here refers to a moment that causes the end of the input shaft 26 on the opposite input side to bend. Furthermore, in order to resist the overturning moment acting on the input shaft 26, it is not necessary to insert the motor shaft 16 deeply into the hollow portion 26b of the input shaft 26. Therefore, while resisting the overturning moment acting on the input shaft 26, ease of assembly when connecting the input shaft 26 to the motor shaft 16 can be ensured.

In relation to such effects, the bolt 62 may apply the axial force F1 directly to the input shaft 26 instead of the seat member 64. In this case, it is sufficient to provide a solid portion in the opposite-to-input side portion of the input shaft 26 where the hollow portion 26b was located, and then seat the bolt 62 on the solid portion of the input shaft 26. In this case, there is an advantage that the number of parts can be reduced because the seat member 64 can be omitted.

Further, when inserting the seat member 64 into the hollow portion 26b provided on the input shaft 26 as described above, the input shaft 26 is provided with a hollow portion 26b that penetrates in the axial direction X. In this case, there is an advantage that large changes in wall thickness are unlikely to occur over the entire range of the input shaft 26 in the axial direction X, and it becomes easier to uniformly provide the quenched hardened layer over the entire range.

(Second Embodiment) Refer to FIG. 5. The speed reduction device 14 of this embodiment differs from the first embodiment in the presence or absence of an input shaft bearing 70, which will be described next. Specifically, in the first embodiment, an example has been described in which input shaft bearings are not arranged on both sides of the external gear 30 in the axial direction. The speed reducer 14 of this embodiment includes an input shaft bearing 70 that is disposed on the side opposite to the external gear with respect to the first regulating member 50A and supports the input shaft 26. The input shaft bearing 70 is arranged between the first shaft fixing member 52A and the first regulating member 50A. Specific examples of the input shaft bearing 70 are not particularly limited, but include, for example, a ball bearing, a roller bearing, and the like. The input shaft bearing 70 includes a rolling element 70a, an outer ring 70b arranged on the first carrier 38A, and an inner ring 70c arranged on the input shaft 26.

The input shaft bearing 70 is arranged in a shaft insertion hole 38a formed in the first carrier 38A and into which the input shaft 26 is inserted. The shaft insertion hole 38a is not provided with a movement restricting portion such as a stepped portion or a retaining ring that restricts the axial movement of the input shaft bearing 70 toward the side opposite to the externally toothed gear. Thereby, the shape of the shaft insertion hole 38a can be simplified, and the cost required for machining (cutting, etc.) to obtain the shaft insertion hole 38a can be reduced.

The input shaft bearing 70 is restricted from moving in the axial direction toward the side opposite to the externally toothed gear relative to the input shaft 26 . In this embodiment, this is realized by the first shaft fixing member 52A, which is arranged on the side opposite to the external gear with respect to the input shaft bearing 70. The first shaft fixing member 52A of this embodiment restricts the axial movement of the first regulating member 50A toward the side opposite to the external gear via the input shaft bearing 70. The first regulating member 50A is regulated from moving in the axial direction toward the side opposite to the external gear due to contact between the input shaft bearing 70 and the inner peripheral portion 50b of the first regulating member 50A. Further, as described above, the axial movement of the first regulating member 50A toward the external gear is regulated by contact with the stepped portion 26a of the input shaft 26. As a result, as described above, the first regulating member 50A is prevented from moving to both sides in the axial direction with respect to the input shaft 26, and is positioned in the axial direction X with respect to the input shaft 26. This requirement is satisfied whether the speed reducer 14 is in the separated state or the assembled state.

As a result, when the input shaft 26 attempts to move to one side (input side) in the axial direction Movement of the shaft 26 can now be restricted.

In addition, the speed reduction device 14 of this embodiment includes the components described in (A) to (D) and (F) to (I) above, and can obtain effects corresponding to those descriptions. .

(Third Embodiment) Refer to FIG. 6. The speed reduction device 14 of this embodiment is different from the first embodiment in terms of a speed reduction device casing 40 and carriers 38A and 38B, which will be described next.

The casing members 40a, 40b, and 40c of the reduction gear casing 40 of this embodiment are a third casing member 40c that is provided on the opposite side of the motor 12 in the axial direction X than the first casing member 40a and accommodates the first carrier 38A. including.

The inner pin 42 of the above-described embodiment has been described as an example in which the inner pin 42 is supported from both sides in the axial direction X by the first carrier 38A and the second carrier 38B. In this embodiment, the other second carrier 38B is not arranged on the opposite side of the first carrier 38A in the axial direction with the external gear 30 interposed therebetween. That is, the speed reduction device 14 of this embodiment includes only the first carrier 38A and does not include the second carrier 38B. With this structure, the inner pin 42 of this embodiment is cantilevered from one side in the axial direction by a single carrier 38A. Thereby, by omitting the carrier 38B of the speed reducer 14, the axial dimension of the speed reducer 14 can be reduced in size.

In addition, the speed reduction device 14 of this embodiment includes the components described in (A) to (I) above, and can obtain effects corresponding to the descriptions.

Next, modifications of each of the constituent elements described so far will be described. Hereinafter, when the components (regulating member 50, shaft fixing member 52, etc.) whose numbers are suffixed with "A, B" are referred to generically, this will be omitted.

The type of eccentric rocking type reduction gear 14 is not particularly limited. As an example of this, the eccentric rocking type speed reduction device 14 may be of a distribution type in which a plurality of input shafts 26 are arranged at positions offset from the center C32 of the internal gear 32.

In the embodiment, an example has been described in which "one side in the axial direction X" is the input side, and "the other side in the axial direction X" is the opposite input side. In addition, "one side in the axial direction X" may be the opposite input side, and "the other side in the axial direction X" may be the input side. For example, in the first to third embodiments, an input shaft bearing is not disposed on the input side, which is one side in the axial direction X with respect to the reduction gear 14, and An example has been described in which the first regulating member 30A is arranged on the opposite input side, which is the other side. Alternatively, the input shaft bearing is not arranged on the opposite input side which is one side in the axial direction X with respect to the reduction gear 14, and the input side which is the other side in the axial direction X with respect to the external gear 30. This means that the first regulating member 30A may be disposed at. In this case, as in the second embodiment, the input shaft bearing 70 may be arranged on the input side that is the other side in the axial direction X with respect to the external gear 30, or as in the first embodiment, the input shaft bearing 70 The bearing 70 may be omitted.

An example has been described in which the axial movement of the first regulating member 50A with respect to the input shaft 26 is regulated by the first shaft fixing member 52A. Without being limited to this, the first regulating member 50A itself may be fixed to the input shaft 26 in the axial direction X, thereby regulating movement in the axial direction with respect to the input shaft 26. This is assumed to be realized, for example, by fitting a part of the first regulating member 50A into a groove formed in the input shaft 26.

An example has been described in which the second regulating member 50B is regulated from moving in the axial direction with respect to the input shaft 26 by the second shaft fixing member 52B. The present invention is not limited thereto, and axial movement with respect to the input shaft 26 may be restricted by fixing the second regulating member 50B itself in the axial direction X with respect to the input shaft 26. This is assumed to be realized, for example, by fitting a part of the second regulating member 50B into a groove formed in the input shaft 26. Further, the second regulating member 50B may be arranged at a position that does not overlap with the external gear 30 in the axial direction X, and may have only the function of regulating the axial movement of the eccentric bearing 36.

The first regulating member 50A and the second regulating member 50B do not have to regulate the axial movement of the eccentric bearing 36. This assumes, for example, that a bearing regulating member for regulating the axial movement of the eccentric bearing 36 is provided separately from the regulating members 50A and 50B.

Specific examples of the first shaft fixing member 52A and the second shaft fixing member 52B are not limited to retaining rings. The first shaft fixing member 52A and the second shaft fixing member 52B may be, for example, a collar, a nut, or the like. This collar may be fixed to the input shaft 26 in the axial direction X by press fitting. This nut may be fixed to the input shaft 26 in the axial direction by screwing into a male thread provided on the input shaft 26. Further, the first shaft fixing member 52A may be constituted by an input shaft bearing 70 fixed to the input shaft 26 by interference fit or the like.

The input shaft 26 does not need to be fastened to the motor shaft 16 in the axial direction X by the bolt 62.

The above embodiments and modifications are illustrative. These abstracted technical ideas should not be interpreted as being limited to the contents of the embodiments and modified forms. The contents of the embodiments and modified forms may be subject to many design changes such as changes, additions, and deletions of constituent elements. In the embodiments described above, the content that allows such design changes is emphasized by adding the notation "embodiment". However, design changes are allowed even if there is no such notation. The hatching added to the cross section of the drawing does not limit the material of the hatched object. Naturally, the structures/numerical values referred to in the embodiments and modifications include those that can be considered to be the same when manufacturing errors and the like are taken into account.

In the embodiment, a component made up of a single member may be made up of a plurality of members. Similarly, a component configured with multiple members in an embodiment may be configured with a single member.

12...Motor, 14...Reduction device, 16...Motor shaft, 26...Input shaft, 28...Eccentric body, 30...External gear, 36...Eccentric bearing, 38A, 38B...Carrier, 42...Inner pin, 50A...First Regulation member, 50B...Second regulation member, 52A...First shaft fixing member, 52B...Second shaft fixing member, 62...Bolt, 70...Input shaft bearing.

Claims (10)

An eccentric rocking type speed reduction device comprising an input shaft, an eccentric body provided on the input shaft, and an external gear rocked by the eccentric body,
An input shaft bearing supporting the input shaft is not disposed on one side in the axial direction with respect to the external gear,
a first regulating member disposed on the other side in the axial direction with respect to the external gear, and regulating movement in the axial direction with respect to the input shaft;
At least a portion of the first regulating member is an eccentric swing type speed reduction device that overlaps the external gear in the axial direction. comprising an eccentric bearing disposed between the external gear and the eccentric body,
The eccentric rocking speed reduction device according to claim 1, wherein the first regulating member regulates axial movement of the eccentric bearing. Claim: further comprising a first shaft fixing member disposed on the side opposite to the external gear with respect to the first regulating member, fixed in the axial direction with respect to the input shaft, and regulating axial movement of the first regulating member. 3. Eccentric oscillation type reduction gear according to 1 or 2. The eccentric rocking type speed reduction device according to claim 3, wherein the first shaft fixing member is a retaining ring. an input shaft bearing disposed on the side opposite to the externally toothed gear with respect to the first regulating member, and axial movement of the input shaft in the side opposite to the externally toothed gear is restricted;
The eccentric rocking speed reduction device according to any one of claims 1 to 4, wherein the first regulating member is regulated in axial movement by the input shaft bearing. An input shaft bearing supporting the input shaft is not arranged on the other side with respect to the external gear,
a second regulating member disposed on the one side with respect to the external gear and regulating axial movement with respect to the input shaft;
The eccentric rocking type speed reduction device according to any one of claims 1 to 4, wherein at least a portion of the second regulating member overlaps the external gear in the axial direction. Claim: further comprising a second shaft fixing member disposed on the side opposite to the external gear with respect to the second regulating member, fixed in the axial direction with respect to the input shaft, and regulating movement of the second regulating member in the axial direction. 6. The eccentric rocking type speed reduction device according to 6. The eccentric rocking type speed reduction device according to claim 7, wherein the second shaft fixing member is a retaining ring. a carrier disposed laterally in the axial direction with respect to the external gear;
an inner pin that passes through the external gear and synchronizes the rotational component of the external gear with the carrier;
9. The eccentric rocking speed reduction device according to claim 1, wherein no other carrier is disposed on the opposite side of the carrier in the axial direction across the external gear. The eccentric swing according to claim 1, wherein the input shaft is separate from an external motor shaft that inputs rotation to the input shaft, and is axially fastened to the motor shaft with a bolt. Type reduction device.

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