JP7227800B2 - internal planetary gear - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal planetary gear system, and more particularly to an internal planetary gear system in which a connecting pin (inner pin) regulates the oscillating motion of an internal gear or the like with respect to a fixed member.

The internal planetary gear device has a fixed member such as an outer case, a fixedly arranged annular internal gear having internal teeth on the inner peripheral portion, and external teeth having a smaller number of teeth than the internal teeth on the outer peripheral portion. an external gear inside the internal gear and meshing with the internal gear; an output shaft coupled with the external gear; There is known a constant velocity internal gear type one having a coupling mechanism that allows relative eccentric oscillation (translational movement on a circular trajectory) and couples to the fixed member (see, for example, Patent Document 1).

The connection mechanism of the internal planetary gear device described above is formed on the inner peripheral portion of the fixed member and the outer peripheral portion of the internal gear so as to face each other about an axis parallel to the central axis of these members. It has an arcuate concave surface and a pin sandwiched between both arcuate concave surfaces, and the pin has an outer diameter smaller than the inner diameter of the arcuate concave surface, and both ends are formed on the fixing member and are larger than the outer diameter of the pin. The internal gear is loosely fitted in the engagement hole of the inner diameter, and the intermediate portion is engaged with both arcuate concave surfaces so as to be able to roll, and the internal gear is eccentrically oscillated with respect to the fixed member with a predetermined eccentricity. It regulates rocking motion.

JP 2017-25979 A

In the above-described coupling mechanism, one of the arc concave surfaces facing each other is formed on the fixed member, and the other arc concave surface is formed on the internal gear, which is a separate member from the fixed member. In addition to the dimensional error, the positional relationship between the arcuate concave surface of the fixed member and the arcuate concave surface of the internal gear is difficult to achieve as designed.

For this reason, in the above-described coupling mechanism, the eccentric oscillation of the internal gear with respect to the fixed member is not performed as designed, and the reduction in the engagement ratio between the internal gear and the external gear causes uneven rotation, resulting in stable operation. is not performed and noise and vibration during operation increase.

Such a problem also occurs in an internal planetary gear system in which an external gear eccentrically oscillates with respect to a fixed member, and an internal planetary gear system in which an external gear eccentrically oscillates with respect to an output shaft. occur.

The problem to be solved by the present invention is that in an internal planetary gear device, the eccentric oscillation of the internal gear or the external gear with respect to the fixed member and the eccentric oscillation of the external gear with respect to the output shaft do not occur as designed. It is to suppress the decrease in the meshing ratio between the internal gear and the external gear.

An internal planetary gear device according to one embodiment of the present invention comprises: a fixed member (10); an output shaft (34) rotatably supported by the fixed member (10); The first gears (22, 40) are coupled to each other through a coupling mechanism (50) so as to be able to move in translation along a circular locus, and are coaxially coupled to the output shaft (34). 22, 40) and second gears (22, 40) inscribed and engaged with each other with a predetermined eccentricity, wherein the connection mechanism (50) a connecting pin (56) fixed to one of the member (10) and the first gear (22, 40) and extending in the axial direction of the first gear (22, 40); (10) and a round hole (52, 54) formed in the other of said first gear and receiving said connecting pin (56) with an amount of play corresponding to said amount of eccentricity.

According to this configuration, the eccentric oscillation of the first gear (22, 40) or the second gear (22, 40) with respect to the fixed member (10) is prevented from being performed as designed. A decrease in the engagement ratio between the gears (22, 40) and the second gears (22, 40) is suppressed.

In the internal planetary gear device, the first gear is an annular internal gear (22) having internal teeth (24) on the inner periphery, and the second gear is the internal teeth on the outer periphery. (24) an external gear (40) having a smaller number of teeth (42) and being inside the internal gear (22) and meshing with the internal gear (22), or the second The first gear is an annular internal gear (22) having internal teeth (24) on the inner circumference, and the first gear has external teeth (42) having fewer teeth than the internal teeth (24) on the outer circumference. ) inside the internal gear (22) and meshing with the internal gear (22).

As a result, the eccentric oscillation of the internal gear (22) or the external gear (40) with respect to the fixed member (10) is prevented from occurring as designed, and the internal gear (22) and the external gear (40) ) is suppressed.

In the internal planetary gear device, preferably, the round hole (52) is a through hole axially penetrating the annular portion of the internal gear (22).

According to this configuration, the round hole (52) can be easily configured without complicating the structure.

In the above internal planetary gear device, preferably, the internal gear (22) has an annular gear body (23) having the internal teeth (24) on its inner periphery and an axis of the gear body (23). Each end plate (25) has at least one tongue (25A) located outside the outer circumference of the gear body (23). , The round hole (52) is a through hole that passes through the tongue (25A) in the axial direction.

According to this configuration, the round hole (52) does not adversely affect the magnetic properties of the internal gear (22) as the rotor.

An internal planetary gear device according to one embodiment of the present invention comprises a fixed member (10), an output shaft (34) rotatably supported by the fixed member (10), and fixed to the fixed member (10). and an annular internal gear (22) having internal teeth (24) on the inner periphery thereof, and the output shaft (34) are connected to the output shaft (34) through a connection mechanism (50) so as to be capable of translating in a circular locus. , an external tooth (42) inside the internal gear (22) and having a smaller number of teeth than the internal tooth (24) on the outer periphery thereof and having a predetermined eccentricity with respect to the internal gear (22) and an external gear (40) meshing with the internal gear (22), wherein the connection mechanism (50) comprises the output shaft (34) and A connecting pin (56) fixed to one of the external gears (40) and extending in the axial direction of the external gear (40), the output shaft (34) and the external gear (40) and a round hole (52, 74) formed in either one of the two and receiving the connecting pin (56) with an amount of play corresponding to the amount of eccentricity.

This configuration prevents the external gear (40) from eccentrically oscillating with respect to the output shaft (34) as designed, and the meshing between the internal gear (22) and the external gear (40). Decrease in rate is suppressed.

In the internal planetary gear device, preferably, the round holes (52, 54) have an inner diameter larger than the outer diameter of the connecting pin (56) by the amount of eccentricity.

According to this configuration, under eccentric oscillation of the internal gear (22) or the external gear (40) with respect to the fixed member (10) or under eccentric oscillation of the external gear (40) with respect to the output shaft (34), The meshing between the internal gear (22) and the external gear (40) is properly performed without overloading.

In the above internal planetary gear device, preferably, the fixed member (10) and the internal gear (22) include surfaces opposed to each other in the axial direction, and between the surfaces the fixed member (10) is A thrust support portion (30) is provided to regulate axial displacement and inclination of the internal gear (22).

According to this configuration, the internal gear (22) is restricted from displacing in the axial direction with respect to the fixing member (10) and from tilting with respect to the central axis. Rotational motion of the external gear (40) with respect to the member (10) is facilitated as designed.

In the above internal planetary gear device, preferably, the thrust support portion (30) includes a plurality of balls (28) individually provided at at least three locations apart from each other in the circumferential direction of the internal gear.

According to this configuration, the displacement of the internal gear (22) in the axial direction with respect to the fixed member (10) and the regulation of the inclination of the internal gear (22) with respect to the central axis provide a large frictional resistance. done without happening.

In the above internal planetary gear device, preferably, at least one of the opposing surfaces is formed with an annular groove (26) along the circumferential direction of the internal gear (22), and the annular groove ( 26), the ball (28) is rotatably arranged.

According to this configuration, the thrust support of the internal gear (22) by the balls (28) is stably and appropriately performed.

In the above internal planetary gear device, preferably, the thrust support portions (30) are provided at least three locations on the fixed member (10) spaced apart in a direction corresponding to the circumferential direction of the internal gear (22). The ball housing holes (58) provided, the balls (28) housed in the ball housing holes (58), and the balls (28) are biased toward the surface of the internal gear (22). and a spring (62).

According to this configuration, the thrust support of the internal gear (22) by the balls (28) is performed more reliably.

In the above internal planetary gear device, preferably, the thrust support portion (30) is provided on at least one of the opposing surfaces at least three times apart in a direction corresponding to the circumferential direction of the internal gear (22). It includes a protrusion (64) provided at the point.

This configuration provides thrust support for the internal gear (22) without the need for additional parts.

According to the internal planetary gear device of the present invention, the eccentric oscillation of the internal gear or the external gear with respect to the fixed member and the eccentric oscillation of the external gear with respect to the output shaft are prevented from being performed as designed, A decrease in the engagement ratio between the internal gear and the external gear is suppressed.

1 is a front view showing Embodiment 1 of an internal planetary gear device according to the present invention (a front view with a rear case removed); FIG. 1 is a half-sectional perspective view of an internal planetary gear device according to Embodiment 1. FIG. FIG. 2 is an enlarged cross-sectional view of a main part of the internal planetary gear device according to Embodiment 1; FIG. 4 is an enlarged cross-sectional view showing a modification of the main part of the internal planetary gear device according to Embodiment 1; FIG. 4 is an enlarged cross-sectional view showing a modification of the main part of the internal planetary gear device according to Embodiment 1; FIG. 2 is a front view showing Embodiment 2 of an internal planetary gear device according to the present invention; Half cross-sectional perspective view of an internal planetary gear device according to Embodiment 2 Configuration diagram of internal planetary gear units according to Embodiments 1 and 2 Configuration diagram of an internal planetary gear device according to Embodiment 3 Configuration diagram of an internal planetary gear device according to Embodiment 4

A first embodiment of an internal planetary gear device according to the present invention will be described below with reference to FIGS. 1 to 3. FIG.

The internal planetary gear device of Embodiment 1 is of a direct drive type, and has a hollow outer case (fixing member) 10 formed by an assembly of a front case 12 and a rear case 14 .

A substantially annular stator member 16 that constitutes an eccentric swing motor (variable gap motor) is fixed in the outer case 10 . Six salient poles (teeth) 18 protruding radially inward from the inner peripheral portion of the stator member 16 are formed at predetermined intervals in the circumferential direction. A stator coil 20 is wound around the outer periphery of each salient pole 18 .

A substantially annular internal gear (first gear) 22 is arranged in a radially inner space of the stator member 16 . The internal gear 22 is made of a ferromagnetic material and forms a rotor of a reluctance type eccentric oscillating motor and an input member of an internal planetary gear device. The internal gear 22 is connected to the outer case 10 by a connecting mechanism 50, which will be described later, in a state in which relative eccentric rocking by a predetermined amount of eccentricity E is allowed with respect to the outer case 10. As shown in FIG. The relative eccentric oscillation due to the predetermined amount of eccentricity E referred to here is translational movement by a circular trajectory with a radius corresponding to the amount of eccentricity E without changing the rotation phase around the center of the internal gear 22, that is, This is the motion of the internal gear 22 without changing its attitude around the center of the internal gear 22 .

A plurality of internal teeth 24 are formed on the inner peripheral surface of the internal gear 22 at equal pitches in the circumferential direction.

The front case 12 and the rear case 14 include inner side surfaces 12A and 14A that face outer side surfaces 22A and 22B on both axial sides of the internal gear 22 with a predetermined gap in the axial direction. As shown in FIG. 3, each of the inner side surfaces 12A and 14A is formed with an annular groove 26 that is concentric with the rotation center of an external gear 40, which will be described later. A plurality of balls 28 are rotatably arranged at at least three locations equidistantly spaced apart in the circumferential direction of each annular groove 26 , in other words, in the circumferential direction of the internal gear 22 . Each ball 28 is in contact with the outer surface 22A or 22B of the internal gear 22. As shown in FIG. As a result, thrust support portions 30 by thrust ball bearings are formed on both sides of the internal gear 22 in the axial direction.

Each thrust support portion 30 restricts the axial displacement of the internal gear 22 with respect to the outer case 10 and the inclination of the internal gear 22 with respect to the central axis.

An annular retainer plate 27 is provided in each annular groove 26 where the balls 28 are arranged so that the plurality of balls 28 are arranged at equal intervals in the circumferential direction as described above. As a result, together with the balls 28 being rotatably arranged in the annular groove 26, the thrust support of the internal gear 22 by the balls 28 is stably and appropriately performed.

The rear case 14 rotatably supports an output shaft 34 with a radial ball bearing 32 . The output shaft 34 includes a portion positioned radially inward of the internal gear 22 , and an external gear (second gear) 40 is fixed to the outer peripheral surface of this portion by a screw sleeve 36 . The front case 12 rotatably supports a screw sleeve 36 with a radial ball bearing 33 .

The external gear 40 is composed of a laminated body of steel plates, and is coaxially fixed (coupled) to the output shaft 34 by radial ball bearings 32 and 33 . Moreover, it is eccentrically attached to the internal gear 22 with an amount of eccentricity E so as to be rotatable around its own central axis.

A plurality of external teeth 42 are formed on the outer peripheral surface of the external gear 40 in the circumferential direction with equal modules. A plurality of external teeth 42 are formed. The external teeth 42 have the same pitch as the internal teeth 24 and are provided with a number of teeth that is at least one less than the number of teeth of the internal teeth 24 , and are provided on the eccentric side of the external gear 40 with respect to the internal gear 22 and the internal teeth 24 . are engaged. That is, the external gear 40 is inscribed with the internal gear 22 with a predetermined amount of eccentricity E, and meshes with the internal gear 22 . In the eccentric oscillation of the internal gear 22 with respect to the external gear 40, the side (meshing side) where the internal gear 22 approaches the external gear 40 is called the eccentric side.

As shown in FIG. 3, the connecting mechanism 50 extends in the axial direction through the annular portion of the internal gear 22 at each position (six positions) equally spaced apart in the circumferential direction. A plurality of gear-side round holes 52, and case-side round holes (fixed-side round holes) 54 formed in each of the front case 12 and the rear case 14 corresponding to the gear-side round holes 52 and extending in the coaxial direction. , a connecting pin (inner pin) 56 having a circular cross-section including ends inserted into the respective case-side round holes 54 through the gear-side round holes 52 .

Since the gear-side round hole 52 is a through-hole that axially penetrates the annular portion of the internal gear 22 , the gear-side round hole 52 does not complicate the structure of the internal gear 22 .

The inner diameter of each case-side round hole 54 is substantially equal to the outer diameter of the connecting pin 56 . The connecting pin 56 is fixed to the outer case 10 by press-fitting the end portion into the case-side circular hole 54 . The gear-side round hole 52 is a round hole and has an inner diameter that is larger than the outer diameter of the connecting pin 56 by the amount of eccentricity E.

The coupling mechanism 50 allows eccentric oscillation (translational movement on a circular locus) with respect to the outer case 10 by the amount of eccentricity E without changing the rotation phase of the internal gear 22 with respect to the outer case 10, and the internal gear 22 and the stator member 16 in a torque transmission relationship, in this case, a reaction force receiving relationship.

With this structure, the internal gear 22 can be displaced in a circular locus along the inner peripheral surface of the case-side round hole 54 to which each connecting pin 56 corresponds, without changing the rotational phase around its own center. The case 10 and the external gear 40 are translated along a circular locus with a radius corresponding to the amount of eccentricity E. Thus, an inner pin type constant speed internal gear mechanism is constructed.

With the above configuration, each of the salient poles 18 is composed of the stator member 16 wound with the stator coil 20 and the internal gear 22 forming the rotor to form a reluctance variable gap motor. is supplied with U-phase, V-phase, and W-phase sinusoidal currents of three-phase AC at predetermined timings, a rotating magnetic field is generated around the center of the stator member 16, and the external teeth 42 rotate to the internal teeth on the eccentric side. 24, the internal gear 22 eccentrically oscillates with the eccentricity E with respect to the stator member 16 under the coupling action of the coupling mechanism 50 without changing the rotational phase.

When the number of teeth of the external gear 42 is Za and the number of teeth of the internal gear 24 is Zb, the eccentric oscillation of the internal gear 22 causes the external gear 40 to rotate at a reduced speed with a reduction ratio G=Za/(Za-Zb). do.

According to the above-described embodiment, the gear-side round hole 52 is defined by the internal gear 22 as a through-hole axially penetrating the internal gear 22. Therefore, the shape of the gear-side round hole 52 is is not affected by component assembly errors. Moreover, since the ends of the connecting pins 56 are fixed to the outer case 10, the positions of the connecting pins 56 with respect to the outer case 10 do not change.

As a result, the external gear 40 can easily oscillate eccentrically with respect to the outer case 10, which is restricted by loosely fitting the connecting pin 56 into the gear-side round hole 52, as designed. As a result, a decrease in the meshing ratio between the internal gear 22 and the external gear 40 is suppressed, and uneven rotation is less likely to occur, resulting in stable operation and reduced noise and vibration during operation. .

Since the inner diameter of the gear-side round hole 52 is larger than the outer diameter of the connecting pin 56 by the amount of eccentricity E, the internal gear 22 and the external gear 40 are displaced from each other when the internal gear 22 is eccentrically oscillated with respect to the outer case 10 . is properly engaged without overloading.

In addition, since the axial displacement of the internal gear 22 with respect to the outer case 10 and the inclination of the internal gear 22 with respect to the central axis are restricted by the respective thrust support portions 30, The eccentric oscillation of the tooth gear 22 can be easily performed as designed. This also suppresses a decrease in the meshing ratio between the internal gear 22 and the external gear 40, making it difficult for uneven rotation to occur, enabling stable operation and reducing noise and vibration during operation. do.

Further, in this embodiment, the displacement of the internal gear 22 in the axial direction with respect to the outer case 10 and the inclination of the internal gear 22 with respect to the central axis are restricted without generating a large frictional resistance. .

4 and 5 show another embodiment of the thrust support 30. FIG.

In the embodiment shown in FIG. 4, each ball 28 on the front case 12 side is inserted into a ball retaining hole 58 formed in the front case 12, and a plug is screwed to the front case 12 within the ball retaining hole 58. A compression coil spring 62 is provided between the ball 28 and the ball 28 to bias the ball 28 toward the outer surface 22A of the internal gear 22 .

In this embodiment, the thrust support portion 30 on the front case 12 side is preloaded by the compression coil spring 62, and the balls 28 are pressed against the outer surface 22A of the internal gear 22. rattling in the thrust direction is eliminated. As a result, axial displacement of the internal gear 22 with respect to the outer case 10 and inclination of the internal gear 22 with respect to the central axis are more reliably restricted. The sets of the balls 28, the plugs 60, and the compression coil springs 62 may be provided at at least three locations in the circumferential direction of the front case 12. As shown in FIG. This provides stable three-point support.

In the embodiment shown in FIG. 5, in place of the balls 28, hemispherical protrusions 64 protrude from the inner side surfaces 12A, 14A of the front case 12 and the rear case 14 toward the outer side surfaces 22A, 22B of the internal gear 22. are formed integrally with the front case 12 and the rear case 14, respectively. The projections 64 are provided at at least three locations in the circumferential direction of the front case 12 and the rear case 14, and are in contact with the outer surface 22A or 22B of the internal gear 22, respectively.

In this embodiment, the thrust support portion 30 is constructed without the need for additional parts such as the balls 28, and the axial displacement of the internal gear 22 with respect to the outer case 10 and the centering of the internal gear 22 are controlled. Tilting with respect to the axis is restricted.

Next, Embodiment 2 of the internal planetary gear device according to the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 and 7, portions corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

In the internal planetary gear device of Embodiment 2, a plurality of rotor-side salient poles 70 are formed on the outer peripheral surface of the internal gear 22 . A rotor coil 72 is wound around each rotor-side salient pole 70 . Thus, in Embodiment 2, a reluctance type eccentric oscillating motor with a rotor coil is configured.

The internal gear 22 includes an annular gear body 23 having internal teeth 24 on its inner periphery and end plates 25 fixed to both sides of the gear body 23 in the axial direction. Each end plate 25 integrally has a plurality of (six) tongues 25A positioned outside the outer circumference of the gear body 23, and each tongue 25A is provided with a gear-side circular hole axially penetrating through the tongues 25A. 52 are formed. Since the gear-side round hole 52 is provided outside the gear body 23, the gear-side round hole 52 does not adversely affect the magnetic characteristics of the internal gear 22 as a rotor.

Each tongue 25A is arranged between adjacent rotor-side salient poles 70 in the circumferential direction. As a result, the coupling mechanism 50 formed on each tongue 25A has little adverse effect on the magnetic characteristics of the stator coil 20 and the rotor coil 72, and has little effect on the performance of the eccentric oscillating motor.

Also in the second embodiment, the inner diameter of the case-side round hole 54 formed in each of the front case 12 and the rear case 14 is substantially equal to the outer diameter of the connecting pin 56 . The connecting pin 56 is fixed to the outer case 10 by press-fitting the end portion into the case-side circular hole 54 . The gear-side round hole 52 is a round hole and has an inner diameter that is larger than the outer diameter of the connecting pin 56 by the amount of eccentricity E.

Also in Embodiment 2, the gear-side round hole 52 is defined as a through-hole that axially penetrates the end plate 25 of the internal gear 22 , and is defined entirely by the end plate 25 . The shape is not affected by part assembly errors. Moreover, since the ends of the connecting pins 56 are fixed to the outer case 10, the positions of the connecting pins 56 with respect to the outer case 10 do not change.

As a result, the rotational movement (eccentric oscillation) of the external gear 40 with respect to the outer case 10, which is restricted by loosely fitting the connecting pin 56 in the gear-side round hole 52, can be easily performed as designed. As a result, a decrease in the meshing ratio between the internal gear 22 and the external gear 40 is suppressed, and uneven rotation is less likely to occur, resulting in stable operation and reduced noise and vibration during operation. .

By loosely fitting the connecting pin 56 in the gear-side round hole 52 of the end plate 25, the contact area with the external gear 40 in the gear-side round hole 52 is smaller than that of the first embodiment, and friction resistance is increased. becomes less.

FIG. 8 is a configuration diagram of the internal planetary gear of Embodiments 1 and 2 described above, in which the eccentrically oscillating internal gear 22 forms an input member and is connected between the internal gear 22 and the outer case 10 . Mechanism 50 is shown to be provided.

FIG. 9 shows Embodiment 3 of an internal planetary gear device according to the present invention. In Embodiment 3, the external gear 40 constitutes the first gear that eccentrically oscillates with respect to the outer case 10, and the output shaft 34 is connected to the internal gear 22 so that the internal gear 22 constitutes the second gear. , a connecting mechanism 50 similar to that of the above-described embodiment is provided between the external gear 40 and the outer case 10 . In this case, the gear-side round hole 52 is provided in the external gear 40 .

Therefore, the internal planetary gear device of Embodiment 3 can also obtain the same functions and effects as those of the above-described embodiments.

FIG. 10 shows Embodiment 4 of an internal planetary gear device according to the present invention. In the fourth embodiment, the internal gear 22 is fixed to the outer case 10, the external gear 40 constitutes an input member that eccentrically oscillates with respect to the output shaft 34, and the above-described A connecting mechanism 50 similar to that of the embodiment is provided. In this case, the external gear 40 is provided with a gear-side round hole 52, the output shaft 34 is provided with an output-shaft-side round hole 74, and the connecting pin 56 is formed in either the gear-side round hole 52 or the output-shaft-side round hole 74. It is loosely fitted on one side and press-fitted on the other side to be fixed to the external gear 40 or the output shaft 34 . The inner diameter of the gear-side round hole 52 or the output-shaft-side round hole 74 into which the connecting pin 56 is loosely fitted has an inner diameter larger than the outer diameter of the connecting pin 56 by the amount of eccentricity E of the eccentric oscillation of the external gear 40 .

Therefore, in the internal planetary gear device of Embodiment 4 as well, functions and effects similar to those of the above-described embodiments can be obtained.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and can be modified as appropriate without departing from the scope of the present invention.

For example, in Embodiments 1 and 2 and the embodiments shown in FIGS. 8 and 9, the connecting pin 56 is press-fitted into the gear-side round hole 52 and fixed to the internal gear 22 or the external gear 40. may be loosely fitted in the round hole 54 on the case side, which is larger than the outer diameter of the connecting pin 56 .

In the embodiment shown in FIG. 10 , the connecting pin 56 is loosely fitted in the gear-side round hole 52 formed in the external gear 40 and having an inner diameter larger than the outer diameter of the connecting pin 56 . , or is press-fitted into the gear-side round hole 52 and fixed to the internal gear 22, and the inner diameter is outside the connecting pin 56. It may be loosely fitted in the output shaft side round hole 74 having a larger diameter.

The connection pin 56 may be fixed to the outer case 10, the internal gear 22, the external gear 40, or the output shaft 34 by a method other than press-fitting, including integrally forming them.

The numbers of salient poles 18, rotor-side salient poles 70, and coupling mechanisms 50 are not limited to six. In the embodiment of thrust support portion 30 shown in FIG. 3, annular groove 26 may be formed in rear case 14 or both front case 12 and rear case 14 .

Further, all of the components shown in the above embodiments are not necessarily essential, and can be appropriately selected without departing from the gist of the present invention.

10: Outer case (fixing member)
12: Front case 12A: Inside surface 14: Rear case 14A: Inside surface 16: Stator member 18: Salient poles 20: Stator coil 22: Internal gear (first gear or second gear)
22A: Outer surface 22B: Outer surface 23: Gear body 24: Internal tooth 25: End plate 25A: Tongue piece 26: Annular groove 27: Retainer plate 28: Ball 30: Thrust support portion 32: Radial ball bearing 33: Radial ball Bearing 34 : Output shaft 36 : Screw sleeve 38 : Ball 40 : External gear (first gear or second gear)
42 : External tooth 50 : Connection mechanism 52 : Gear side round hole 54 : Case side round hole 56 : Connection pin 58 : Ball holding hole 60 : Plug 62 : Compression coil spring 64 : Protrusion 70 : Rotor side salient pole 72 : Rotor coil 74: Output shaft side round hole

Claims (4)

a fixing member;
an output shaft rotatably supported by the fixed member;
a first gear coupled to the fixed member via a coupling mechanism so as to be capable of translating along a circular locus;
An internal planetary gear device having a second gear that is coaxially coupled to the output shaft and meshes with the first gear by a predetermined amount of eccentricity, wherein
The connecting mechanism is
a connecting pin fixed to one of the fixing member and the first gear and extending in the axial direction of the first gear;
a round hole formed in the other of the fixed member and the first gear and receiving the connecting pin with an amount of play corresponding to the amount of eccentricity;
The first gear is an annular internal gear having internal teeth on the inner circumference,
the second gear is an external gear that has external teeth having fewer teeth than the internal teeth on the outer peripheral portion and is inside the internal gear and meshes with the internal gear;
The fixed member and the internal gear include surfaces facing each other in the axial direction, and a thrust support portion is provided between the surfaces to regulate displacement and inclination of the internal gear in the axial direction with respect to the fixed member. ,
The thrust support portion includes ball housing holes provided in at least three locations of the fixed member separated in a direction corresponding to the circumferential direction of the internal gear, balls housed in the respective ball housing holes, and the respective balls. toward said surface of said internal gear. a fixing member;
an output shaft rotatably supported by the fixed member;
a first gear coupled to the fixed member via a coupling mechanism so as to be capable of translating along a circular locus;
An internal planetary gear device having a second gear that is coaxially coupled to the output shaft and meshes with the first gear by a predetermined amount of eccentricity, wherein
The connecting mechanism is
a connecting pin fixed to one of the fixing member and the first gear and extending in the axial direction of the first gear;
a round hole formed in the other of the fixed member and the first gear and receiving the connecting pin with an amount of play corresponding to the amount of eccentricity;
The first gear is an annular internal gear having internal teeth on the inner circumference,
the second gear is an external gear that has external teeth having fewer teeth than the internal teeth on the outer peripheral portion and is inside the internal gear and meshes with the internal gear;
The fixed member and the internal gear include surfaces facing each other in the axial direction, and a thrust support portion is provided between the surfaces to regulate displacement and inclination of the internal gear in the axial direction with respect to the fixed member. ,
The internal planetary gear device, wherein the thrust support portion includes protrusions provided at least three locations on at least one of the opposing surfaces, the projections being spaced apart in a direction corresponding to the circumferential direction of the internal gear. 3. The internal planetary gear device according to claim 1, wherein the round hole is a through hole axially penetrating the annular portion of the internal gear. The internal gear includes an annular gear body having the internal teeth on its inner periphery and end plates fixed to both sides in the axial direction of the gear body,
each end plate integrally has at least one tongue located outside the outer circumference of the gear body;
3. An internal planetary gear device according to claim 1, wherein said round hole is a through hole axially penetrating said tongue.

Images