JP6877318B2 - Gear motor - Google Patents

Description

The present invention relates to a gear motor.

Patent Document 1 discloses a gear motor including a motor and a speed reducer. The speed reducer of this gear motor includes an input shaft (101) that rotates integrally with the motor shaft (124), an eccentric body (103) provided on the input shaft, and an external gear (10) that swings due to the eccentric body. 105) (the reference numerals in FIG. 1 of Patent Document 1 are shown in parentheses).

In such a speed reducer, the vibration of the external gear appears as vibration when the gear motor is operated. Therefore, in the gear motor of Patent Document 1, a balance weight (130) is provided in an empty space in the motor to reduce vibration.

Further, conventionally, in such a speed reducer, in order to reduce the vibration caused by the swing of the external gears, a plurality of external gears having different phases of swing may be provided.

Japanese Unexamined Patent Publication No. 10-51999

However, the conventional gear motor has not been able to sufficiently reduce the vibration.

An object of the present invention is to provide a gear motor capable of further reducing vibration.

The present invention
A gear motor equipped with a motor and a speed reducer.
The motor has a stator in which a coil is wound and a rotor shaft having a rotor.
The speed reducer has an input shaft that rotates coaxially with the rotor shaft, an eccentric body provided on the input shaft, and a swing gear that swings by the eccentric body.
The phase of the eccentric body and the phase of the rotating magnetic field of the motor so that the load acting on the rotor shaft due to the rotating magnetic field of the motor is generated in the direction of canceling the load acting on the input shaft due to the rotation of the eccentric body. The motor and the speed reducer are connected to each other.

According to the present invention, it is possible to provide a gear motor capable of further reducing vibration.

It is sectional drawing which shows the gear motor of Embodiment 1 which concerns on this invention. FIG. 2A is a diagram showing the stator and rotor of the first embodiment, and FIG. 2B is a diagram illustrating a load acting on the input shaft and the rotor shaft of the first embodiment. FIG. 3A is a diagram showing a stator and a rotor of the gear motor of the second embodiment according to the present invention, and FIG. 3B is a diagram illustrating a load acting on the input shaft and the rotor shaft of the second embodiment, FIG. 3 (B). C) is a diagram for explaining the magnitude of the load acting on the input shaft and the rotor shaft of the second embodiment. FIG. 4 (A) shows a stator and a rotor of the gear motor according to the third embodiment of the present invention, and FIG. 4 (B) shows a load acting on the input shaft and the rotor shaft of the third embodiment, FIG. 4 (B). C) is a diagram for explaining the magnitude of the load acting on the input shaft and the rotor shaft of the third embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a gear motor according to the first embodiment of the present invention. FIG. 2A is a diagram showing the stator and rotor of the first embodiment, and FIG. 2B is a diagram illustrating a load acting on the input shaft and the rotor shaft of the first embodiment. Hereinafter, the direction along the rotation axis O1 of the input shaft 12 and the rotor shaft 4 is defined as the axial direction, the direction perpendicular to the rotation axis O1 is defined as the radial direction, and the rotation direction centered on the rotation axis O1 is defined as the circumferential direction.

The gear motor 1 of the first embodiment includes a motor M1 and a speed reducer G1.

<Structure of motor M1>
As shown in FIG. 1, the motor M1 has a stator 3 around which a coil is wound, a rotor shaft 4 having a rotor 4a, and a third casing 33, a fourth casing 34, and a fifth casing 35 that cover the rotor 4a. .. The rotor 4a refers to a portion where an electromagnetic force is applied from the stator 3.

The rotor shaft 4 has, for example, a hollow structure, and is rotatably supported by, for example, a third casing 33 and a fifth casing 35 via bearings (for example, ball bearings) 41 and 42. The bearings 41 and 42 are arranged on both sides of the rotor 4a in the axial direction and on the rotor shaft 4 side of the eccentric body 14 of the speed reducer G1 described later.

The motor M1 of the first embodiment adopts a structure in which a shaft excitation force in one direction is generated. The shaft exciting force corresponds to the load F1 (details will be described later) generated on the rotor 4a by the rotating magnetic field generated by the stator 3. The motor M1 that generates a unidirectional axial centering force has a fractional slot structure such as a 2-pole 3-slot, an 8-pole 9-slot, and a 10-pole 9-slot. Here, the number of poles indicates the number of magnetic poles that are alternately arranged with N poles and S poles on the outer circumference of the rotor 4a. The number of slots indicates the number of slots (between a pair of adjacent segments) through which the wiring of the coil 3b is passed in the stator core 3a, and is the same as the number of segments described later. The fractional slot refers to a motor structure in which the number of slots per pole and phase is a fraction. Subsequently, a specific example to which the structure of 8 poles and 9 slots is applied will be described.

As shown in FIG. 2A, the stator 3 has a stator core 3a which is a magnetic material and a coil 3b wound around the stator core 3a. The coil 3b is divided into three sets of coils through which currents of three phases (u phase, v phase, and w phase) whose phases are 120 degrees different from each other are passed. Further, the stator core 3a has a plurality of segments Seg1 to Seg9 that generate a magnetic field by each of the three-phase currents. In the stator core 3a of the first embodiment, as shown in FIG. 2A, the u-phase three segments Seg1 to Seg3, the v-phase three segments Seg4 to Seg6, and the w-phase three segments Seg7 to Seg9. Are provided side by side. The u-phase segments Seg1 to Seg3 generate a magnetic field having a magnitude corresponding to the u-phase current and directed toward the center of the axis. The v-phase segments Seg4 to Seg6 generate a magnetic field oriented toward the center of the axis with a magnitude corresponding to the v-phase current. The w-phase segments Seg7 to Seg9 generate a magnetic field oriented toward the center of the axis with a magnitude corresponding to the w-phase current.

The rotor 4a has a plurality of permanent magnets 4b1 to 4b8 fixed to the rotor shaft 4. For example, in the first embodiment, eight permanent magnets 4b1 to 4b8 are provided in eight sections divided into eight equal parts in the rotation direction. The eight permanent magnets 4b1 to 4b8 are arranged so that the S poles and the N poles alternately face each other on the outer peripheral side.

<Operation of motor M1>
When the stator 3 is driven by a three-phase current, a rotating magnetic field Hr1 (see FIG. 2A) in a direction orthogonal to the rotation axis O1 is generated in the center of the rotor 4a. The rotating magnetic field Hr1 is a combined magnetic field of a plurality of magnetic fields generated by each of the plurality of segments Seg1 to Seg9 of the stator core 3a, and the magnitude of the magnetic field does not depend on the rotation angle and is in the circumferential direction according to the three-phase current. It is a magnetic field whose direction rotates toward. If the effective value of the three-phase current does not change, the magnitude of the rotating magnetic field Hr1 does not change.

The rotor 4a receives a magnetic field generated from each segment Seg1 to Seg9 of the stator 3 and generates torque centered on the rotation shaft O1. Further, a load F1 (see FIGS. 1 and 2B) acts on the rotor 4a in a direction orthogonal to the rotation axis O1 by the rotating magnetic field Hr1. The load F1 is typically generated in the same direction as the rotating magnetic field Hr1 and in the same direction as or in the opposite direction to the rotating magnetic field Hr1 depending on the arrangement of the magnetic poles of the rotor 4a.

<Structure of reducer G1>
The speed reducer G1 is an eccentric swing type speed reducer. The speed reducer G1 has an eccentric body 14, an input shaft 12 that rotates coaxially with the rotor shaft 4, an external gear 22 that is swung by the eccentric body 14, and an external gear 22 that is engaged while swinging. It includes an internal gear 26 to be fitted. Further, the speed reducer G1 covers the plurality of inner pins 28 penetrating the plurality of pin holes 22a of the outer gear 22, the carrier body 29 connected to the inner pins 28, the inner gear 26, and the input shaft 12. It has a first casing 31 and a second casing 32 connected to the internal gear 26. The external gear 22 corresponds to an example of a swing gear according to the present invention.

The input shaft 12 is a shaft having a hollow structure integrally formed with the rotor shaft 4, and rotates about the rotation shaft O1 by driving the motor M1. The rotor shaft 4 and the input shaft 12 may be formed separately and connected to each other.

The input shaft 12 is rotatably supported by the integrated rotor shaft 4 being supported by bearings 41 and 42. The input shaft 12 is not supported by a bearing on the opposite side of the motor M1 from the eccentric body 14.

The outer peripheral surface of the eccentric body 14 has a curved surface shape on the side surface of a cylinder, and the center line of the outer peripheral surface is eccentric from the rotation axis O1.

The external gear 22 is swingably incorporated into the outer periphery of the eccentric body 14 via a roller bearing 18, and is inscribed and meshed with the internal gear 26. The external gear 22 has a plurality of pin holes 22a at positions offset from the axis, and the plurality of inner pins 28 penetrate through the external gears 22. Further, the external gear 22 is provided with a trochoidal tooth portion 22b on the outermost peripheral portion.

The carrier body 29 to which the inner pin 28 is connected is connected to the first casing 31 and the third casing 33. The inner pin 28 may be held by the carrier body 29.

The internal gear 26 is rotatably supported by the internal gear main body 26a connected to the second casing 32, the plurality of pin grooves 26c provided in the internal gear main body 26a, and the plurality of pin grooves 26c, respectively. It has a plurality of outer pins 26b. The internal gear 26 is rotatably supported by the first casing 31 via the spindle support 44. The number of internal teeth of the internal gear 26 (the number of external pins 26b) is slightly different from the number of external teeth of the external gear 22 (for example, one more).

<Operation of reducer G1>
When the input shaft 12 rotates, the eccentric body 14 rotates eccentrically, and the external gear 22 swings following this. The external gear 22 is inscribed in the internal gear 26, while the carrier body 29 holding the internal pin 28 is connected to the first casing 31 and the third casing 33. Therefore, the external gear 22 through which the internal pin 28 is penetrated does not rotate about the rotation shaft O1, but the internal gear 26 has a difference in the number of teeth with respect to the external gear 22 every time the eccentric body 14 rotates once. Relative rotation (rotation). As a result, the rotational movement of the input shaft 12 is reduced by a reduction ratio of 1 / (the number of teeth of the external gear 22) and is output as the rotation of the internal gear 26 and the second casing 32.

The external gear 22 swings so that the center of gravity makes one rotation in the circumferential direction around the rotation axis O1 each time the eccentric body 14 makes one rotation. Therefore, a load F2 (see FIGS. 1 and 2B) corresponding to a centrifugal force is generated on the input shaft 12 as the external gear 22 rotates. The load F2 is a force in a direction orthogonal to the rotation axis O1.

<Load generated on input shaft 12 and rotor shaft 4>
As described above, the load F2 caused by the swing of the external gear 22 acts on the input shaft 12. On the other hand, a load F1 caused by the rotating magnetic field Hr1 acts on the rotor shaft 4. As shown in FIG. 2B, the current phases of the stator 3 are adjusted so that these loads F1 and F2 cancel each other out, and the fixed positions of the permanent magnets 4b1 to 4b8 of the rotor 4a are fixed. Has been adjusted. Specifically, the loads F1 and F2 are adjusted so as to be opposite to each other so as to cancel each other out. In the present specification, the directions opposite to each other are not limited to directions that differ exactly by 180 °, but include directions that include an error within ± 10 °. By adjusting the two loads F1 and F2 in opposite directions, the total load due to the rotation applied to the input shaft 12 and the rotor shaft 4 is reduced, thereby reducing the vibration of the gear motor 1.

As shown in the lower part of FIG. 1 showing the relationship between the force point and the fulcrum, the two loads F1 and F2 act at different positions in the axial direction of the input shaft 12 and the rotor shaft 4. Further, the bearings 41 and 42 act as fulcrums A1 and A2. Therefore, when the input shaft 12 and the rotor shaft 4 are bent, vibration due to the bending of the input shaft 12 and the rotor shaft 4 may occur due to the support of the loads F1 and F2 and the fulcrums A1 and A2. Therefore, it is not always preferable that the two loads F1 and F2 are adjusted to have the same magnitude. For example, the magnitudes of the two loads F1 and F2 so that the vibration due to the total load (F1 + F2) and the vibration due to the deflection of the input shaft 12 and the rotor shaft 4 are reduced at an appropriate ratio according to, for example, the usage environment. Should be adjusted.

As described above, according to the gear motor 1 of the first embodiment, the load F2 generated by the eccentric rotation of the external gear 22 and the load F1 generated by the rotating magnetic field Hr1 of the motor M1 are adjusted so as to cancel each other out. ing. Thereby, for example, the vibration caused by the eccentric rotation of the external gear 22 can be reduced without increasing the number of the external gears 22 or adding the balance weight. Therefore, it is possible to reduce the vibration of the gear motor 1 while suppressing the increase in the volume of the gear motor 1.

Further, according to the gear motor 1 of the first embodiment, the number of external gears 22 is one, and the load acting on the rotor shaft 4 by the rotating magnetic field Hr1 and the load acting on the input shaft 12 by the rotation of the eccentric body 14. Are adjusted in opposite directions. Conventionally, if the number of external gears is one, the gear motor can be compactly configured in the axial direction, but there is a problem that the vibration becomes large due to the influence of the swing of the external gears. However, in the first embodiment, the vibration of the gear motor 1 can be reduced after the gear motor 1 is configured to be short in the axial direction without arranging the balance weight.

Further, according to the gear motor 1 of the first embodiment, the input shaft 12 is not bearing on the opposite side of the rotor shaft 4 from the eccentric body 14. By reducing the bearings in this way, it is possible to shorten the axial direction of the gear motor 1 and reduce the volume. Conventionally, the vibration of the end portion of the input shaft 12 increases due to the reduction of the bearing, but in the first embodiment, the load F2 due to the swing of the external gear 22 and the load F1 generated on the rotor shaft 4 are mutual. By canceling each other, the vibration of the end portion of the input shaft 12 can be suppressed.

(Embodiment 2)
FIG. 3A is a diagram showing a stator and a rotor of the gear motor of the second embodiment according to the present invention, and FIG. 3B is a diagram illustrating a load acting on the input shaft and the rotor shaft of the second embodiment, FIG. 3 (B). C) is a diagram for explaining the magnitude of the load acting on the input shaft and the rotor shaft of the second embodiment.

In the gear motor of the second embodiment, the arrangement of the segments Seg11 to Seg16 and the coil 3Ab of the stator 3A and the number of the eccentric body 14 and the external gears 22A1 and 22A2 are different from those of the first embodiment, and other configurations are implemented. It is the same as the first form. Hereinafter, only the differences from the first embodiment will be described in detail.

The stator 3A and rotor 4Aa of the second embodiment each include two sets of components that generate a unidirectional axial excitation force. Such configurations include, for example, 4 poles and 6 slots (2 sets of 2 poles and 3 slots components), 16 poles and 18 slots (2 sets of 8 poles and 9 slot components), and 20 poles and 18 slots (10 poles and 9 slots). A motor structure such as (two sets of slots) is applicable. Subsequently, a specific example to which the structure of 4 poles and 6 slots is applied will be described.

As shown in FIG. 3A, the stator 3A of the second embodiment has a stator core 3Aa having six segments Seg11 to Seg16, and a plurality of coils 3Ab through which a three-phase current is passed. In the second embodiment, u-phase segments Seg11 and Seg14, v-phase segments Seg12 and Seg15, and w-phase segments Seg13 and Seg16 are provided side by side as shown in FIG. 3A.

With such an arrangement, the u-phase, v-phase, and w-phase segments Seg11 to Seg13 provide a rotating magnetic field Hr11 orthogonal to the rotation axis O1 at the center of the rotor 4Aa. Further, another u-phase, v-phase, and w-phase segments Seg14 to Seg16 provide a rotating magnetic field Hr12 orthogonal to the rotation axis O1 at the center of the rotor 4Aa. The rotating magnetic fields Hr11 and Hr12 are opposite to each other, and rotate in the circumferential direction according to the three-phase current.

In the second embodiment, the two rotating magnetic fields Hr11 and Hr12 are set so as to have different sizes from each other. Such a setting can be realized, for example, by making the number of turns of the coil 3Ab wound around the segments Seg11 to Seg13 different from the number of turns of the coil 3Ab wound around the segments Seg14 to Seg16. Alternatively, it can be realized by configuring the segments Seg11 to Seg13 and the segments Seg14 to Seg16 in different sizes.

The rotor 4Aa is configured by fixing a plurality of permanent magnets to the rotor shaft. In the second embodiment, four permanent magnets (not shown) are provided in four sections divided into four equal parts in the rotation direction. These four permanent magnets are arranged so that the S pole and the N pole alternately face each other on the outer peripheral side. The rotor 4Aa receives the magnetic fields generated from the respective segments Seg11 to Seg16 of the stator 3A to generate torque centered on the rotating shaft O1, while the rotors 4Aa are affected by the rotating magnetic fields Hr11 and Hr12 to load FA1 and FA2 (FIG. 3). (B), see FIG. 3 (C)) occurs. The load FA1 generated by receiving the rotating magnetic field Hr11 is typically generated in the same direction as the rotating magnetic field Hr11 and in the same direction as or in the opposite direction to the rotating magnetic field Hr11 depending on the magnetic pole arrangement of the rotor 4Aa. The load FA2 generated by receiving the other rotating magnetic field Hr12 is generated in the opposite direction to the load FA1 generated by the other rotating magnetic field Hr11. Since the sizes of the two rotating magnetic fields Hr11 and Hr12 are different from each other, the sizes of the loads FA1 and FA2 are also different from each other.

The speed reducer G1 of the second embodiment is provided with two eccentric bodies 14 on the input shaft 12, and further includes two external gears 22A1 and 22A2 corresponding to the two eccentric bodies 14. The two eccentric bodies 14 are provided at different positions in the axial direction, and correspondingly, the two external gears 22A1 and 22A2 are also provided at different positions in the axial direction. The two external gears 22A1 and 22A2 are each provided with a plurality of pin holes at positions offset from the axis, and the plurality of internal pins 28 are commonly penetrated.

The two eccentric bodies 14 are arranged so that their eccentric axes (eccentric directions) are 180 degrees out of alignment with each other, and rotate in phases that differ by 180 degrees. Correspondingly, the two external gears 22A1 and 22A2 swing in different phases by 180 degrees. Therefore, the load FA3 caused by the swing of one external gear 22A1 acting on the input shaft 12 and the load FA4 caused by the swing of the other external gear 22A2 are opposite to each other. The load FA3 and the load FA4 have the same size, and the orientation changes in the circumferential direction according to the rotation of the input shaft 12.

In the second embodiment, the current phase of the stator 3A and the permanent magnets 4b1 to 4b8 of the rotor 4Aa cancel each other so that the load FA1 due to the rotating magnetic field Hr11 and the load FA3 due to the swing of the external gear 22A1 cancel each other out. The fixed position of is adjusted. Further, the current phase of the stator 3A and the fixed positions of the permanent magnets 4b1 to 4b8 of the rotor 4Aa so that the load FA2 due to the other rotating magnetic field Hr12 and the load FA4 due to the swing of the other external gear 22A2 cancel each other out. Has been adjusted. Specifically, the load FA1 and the load FA3 are adjusted to be opposite to each other, and the load FA2 and the load FA4 are adjusted to be opposite to each other. By such adjustment, a plurality of loads FA1 to FA4 acting on the input shaft 12 and the rotor shaft 4 cancel each other out to reduce the total load, thereby reducing the vibration of the gear motor according to the second embodiment. Can be done.

As shown in FIG. 3C, the loads FA3 and FA4 by the two external gears 22A1 and 22A2 and the loads FA1 and FA2 caused by the rotating magnetic fields Hr11 and Hr12 are the axial directions of the input shaft 12 and the rotor shaft 4. Acts on different positions. Therefore, when the input shaft 12 and the rotor shaft 4 are bent, vibration due to the bending of the input shaft 12 and the rotor shaft 4 may occur due to the support of the loads FA1 to FA4 and the fulcrums A1 and A2. Therefore, it is not always preferable that the sizes of the four loads FA1 to FA4 are all adjusted to the same size. For example, in the load FA3 and the load FA4, the load FA3 closer to the end has a larger moment centered on the fulcrum A1. Therefore, the load FA2 due to the one rotating magnetic field Hr12 may be adjusted to be larger than the load FA1 due to the other rotating magnetic field Hr11 so as to cancel this moment. The magnitudes of the loads FA1 and FA2 caused by the rotating magnetic fields Hr11 and Hr12 may be appropriately set so as to reduce the vibration to be removed according to the usage environment and the like.

As described above, according to the gear motor of the second embodiment, the loads FA3 and FA4 generated by the swing of the external gears 22A1 and 22A2 and the loads FA1 and FA2 generated by the rotating magnetic fields Hr11 and Hr12 cancel each other out. It is adjusted so that. Thereby, for example, vibration caused by eccentric rotation of the external gears 22A1 and 22A2 can be reduced without adding a balance weight. Therefore, it is possible to reduce the vibration of the gear motor 1 while suppressing the increase in the volume of the gear motor 1.

Further, according to the gear motor of the second embodiment, two sets of the eccentric body 14 and the external tooth gears 22A1 and 22A2 are provided so as to be 180 degrees out of phase with each other. Due to the configuration of the speed reducer, when a plurality of external gears are provided, the axial positions of the loads FA3 and FA4 acting on the input shaft 12 differ due to the arrangement of the external gears 22A1 and 22A2, and this difference in position. Acts on the input shaft 12 as a moment. However, according to the gear motor of the second embodiment, the stators 3A generate two rotating magnetic fields Hr11 and Hr12 having opposite directions and different sizes, and the loads FA1 and FA2 acting on the rotor shaft 4 by the rotating magnetic fields Hr11 and Hr12. The size of is different. With this configuration, it is possible to adjust the external gears 22A1 and 22A2 so as to reduce the moment applied to the input shaft 12 by the loads FA3 and FA4.

(Embodiment 3)
FIG. 4 (A) shows a stator and a rotor of the gear motor according to the third embodiment of the present invention, and FIG. 4 (B) shows a load acting on the input shaft and the rotor shaft of the third embodiment, FIG. 4 (B). C) is a diagram for explaining the magnitude of the load acting on the input shaft and the rotor shaft of the third embodiment. In FIG. 4C, each load FB1 to FB6 is represented by the magnitude of a predetermined directional component (for example, the directional component of the loads FB3 and FB6).

In the gear motor of the third embodiment, the arrangement of the segments Seg21 to Seg29 and the coil 3Bb of the stator 3B and the number of the eccentric body 14 and the external tooth gears 22B1 to 22B3 are different from those of the first embodiment, and other configurations are implemented. It is the same as the first form. Hereinafter, only the differences from the first embodiment will be described in detail.

The stator 3B and rotor 4Ba of the third embodiment each include three sets of components that generate a unidirectional axial excitation force. Such configurations include, for example, 6 poles and 9 slots (3 sets of 2-pole and 3-slot components), 24-pole 27 slots (3 sets of 8-pole and 9-slot components), and 30-pole and 27 slots (10-pole and 9 slots). Structures such as (3 sets of slots) are applicable. Subsequently, a specific example to which the structure of 6 poles and 9 slots is applied will be described.

As shown in FIG. 4A, the stator 3B of the third embodiment has a stator core 3Ba having nine segments Seg21 to Seg29, and a plurality of coils 3Bb through which a three-phase current is passed. In the third embodiment, the u-phase coil 3Bb, the v-phase coil 3Bb, and the w-phase coil 3Bb of the nine segments Seg21 to Seg29 are wound with some overlap. Then, three rotating magnetic fields Hr21, Hr22, and Hr23 orthogonal to the rotation axis O1 are obtained in the center of the rotor 4Ba. The rotating magnetic fields Hr21 to Hr23 face different directions by 120 degrees from each other, and rotate in the circumferential direction according to the three-phase current.

In the third embodiment, at least one of the three rotating magnetic fields Hr21 to Hr23 is set to be different in magnitude from the others. Such a setting can be realized, for example, by adjusting the number of turns of the coil 3Bb wound around each segment Seg21 to Seg29.

The rotor 4Ba is configured by fixing a plurality of permanent magnets to the rotor shaft. In the third embodiment, for example, six permanent magnets (not shown) are provided in six sections divided into six equal parts in the rotation direction. These six permanent magnets are arranged so that the S pole and the N pole are alternately oriented on the outer peripheral side. The rotor 4Ba receives a magnetic field generated from each segment Seg21 to Seg29 of the stator 3B to generate torque centered on the rotating shaft O1, while the rotor 4Ba is affected by the rotating magnetic fields Hr21 to Hr23 and loads FB1 to FB3 (FIG. 4). (B), see FIG. 4 (C)) occurs. The loads FB1 to FB3 are typically in the same direction as the corresponding rotating magnetic fields Hr21 to Hr23, and in the same direction as or opposite to the corresponding rotating magnetic fields Hr21 to Hr23 depending on the magnetic pole arrangement of the rotor 4Ba. Occurs in the direction. Since at least one magnitude of the three rotating magnetic fields Hr21 to Hr23 is different from the others, at least one magnitude of the three loads FB1 to FB3 is different from the others.

The speed reducer G1 of the third embodiment is provided with three eccentric bodies 14 on the input shaft 12, and further includes three external gears 22B1 to 22B3 corresponding to the three eccentric bodies 14. The three eccentric bodies 14 are provided at different positions in the axial direction, and correspondingly, the three external gears 22B1 to 22B3 are also provided at different positions in the axial direction. Each of the three external gears 22B1 to 22B3 is provided with a plurality of pin holes at positions offset from the axis, and the plurality of internal pins 28 are commonly penetrated.

The three eccentric bodies 14 are arranged so that their eccentric axes (eccentric directions) are shifted by 120 degrees from each other, and rotate in phases 120 degrees different from each other. Correspondingly, the three external gears 22B1 to 22B3 swing in different phases by 120 degrees. Therefore, the loads FB4 to FB6 acting on the input shaft 12 from the external gears 22B1 to 22B3 have different orientations by 120 degrees from each other. The three loads FB4 to FB6 have the same magnitude as each other, and their directions change in the circumferential direction according to the rotation of the input shaft 12.

In the third embodiment, the current phase of the stator 3B and the permanent magnets 4b1 to 4b8 of the rotor 4Ba cancel each other so that the load FB1 generated by one rotating magnetic field Hr21 and the load FB4 caused by the swing of one external gear 22B1 cancel each other out. The fixed position of is adjusted. Similarly, the current phase of the stator 3B and the fixed positions of the permanent magnets 4b1 to 4b8 of the rotor 4Ba are set so that the load FB2 and the load FB5 cancel each other out, and the load FB3 and the load FB6 cancel each other out. It has been adjusted. Specifically, the load FB1 and the load FB4 are adjusted to be opposite to each other, the load FB2 and the load FB5 are adjusted to be opposite to each other, and the load FB3 and the load FB6 are adjusted to be opposite to each other. By such adjustment, a plurality of loads acting on the input shaft 12 and the rotor shaft 4 cancel each other out to reduce the total load, whereby the vibration of the gear motor according to the third embodiment can be reduced.

As shown in FIG. 4C, the loads FB4 to FB6 by the three external gears 22B1 to 22B3 and the loads FB1 to FB3 caused by the rotating magnetic fields Hr21 to Hr23 are the axial directions of the input shaft 12 and the rotor shaft 4. Acts on different positions. Therefore, when the input shaft 12 and the rotor shaft 4 are bent, vibration due to the bending of the input shaft 12 and the rotor shaft 4 may occur due to the support of the loads FB1 to FB6 and the fulcrums A1 and A2. Therefore, it is not always preferable that the sizes of the six loads FB1 to FB6 are all adjusted to the same size. For example, when comparing the three loads FB4 to FB6, the load FB4 closer to the end has a larger moment centered on the fulcrum A1. Therefore, in order to cancel this moment, the loads FB2 and FB3 by the rotating magnetic fields Hr22 and Hr23 that generate the opposite moment may be adjusted to be large. The magnitudes of the loads FB1 to FB3 caused by the rotating magnetic fields Hr21 to Hr23 may be appropriately set so as to reduce the vibration to be removed according to the usage environment and the like.

As described above, according to the gear motor of the third embodiment, the loads FB4 to FB6 generated by the swing of the external gears 22B1 to 22B3 and the loads FB1 to FB3 caused by the rotating magnetic fields Hr21 to Hr23 cancel each other out. It is adjusted so that. Thereby, for example, the vibration caused by the swing of the external gears 22B1 to 22B3 can be reduced without adding a balance weight. Therefore, it is possible to reduce the vibration of the gear motor 1 while suppressing the increase in the volume of the gear motor 1.

Further, according to the gear motor of the third embodiment, three sets of the eccentric body 14 and the external tooth gears 22B1 to 22B3 are provided so as to be out of phase with each other by 120 degrees. Due to the configuration of the speed reducer, when a plurality of external gears are provided, the axial positions of the loads FB4 to FB6 acting on the input shaft 12 are different due to the arrangement of the external gears 22B1 to 22B3, and this difference in position. Acts on the input shaft 12 as a moment. However, according to the gear motor of the third embodiment, the stators 3B generate three rotating magnetic fields Hr21 to Hr23 having different directions by 120 degrees from each other, and at least one of the three rotating magnetic fields Hr21 to Hr23 has a different magnitude. .. As a result, the magnitude of at least one of the loads FB1 to FB3 acting on the rotor shaft 4 is different. With this configuration, it is possible to adjust so as to reduce the moment applied to the input shaft 12 by the loads FB4 to FB6 of the three external gears 22B1 to 22B3.

Each embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment. For example, the second embodiment shows a configuration in which the sizes of the two rotating magnetic fields Hr11 and Hr12 are different, and the third embodiment shows a configuration in which the size of any one of the three rotating magnetic fields Hr21 to Hr23 is different from the others. However, these sizes may be the same. Further, in the above embodiment, the configuration in which the balance weight is not provided to the gear motor is shown, but the configuration may have a balance weight. Even in this case, by applying the present invention, it is possible to reduce the balance weight as compared with the case where it is not applied, and to suppress an increase in the volume of the gear motor.

Further, in the present invention, the number, magnitude and direction of the load generated by the rotating magnetic field of the motor and the number, magnitude and direction of the load generated by the rotation of the eccentric body of the speed reducer are adjusted so that the vibration of the gear motor is reduced. Any combination may be used as long as it is set appropriately. For example, a configuration in which a motor generates more rotating magnetic fields than those in the first to third embodiments to apply loads in many directions, and these loads cancel each other out with the loads acted by the rotation of the eccentric body of the speed reducer. It may be adopted. Further, for a speed reducer in which loads in multiple directions are applied by rotation of a plurality of eccentric bodies, a motor generates a rotating magnetic field in one direction so as to cancel out the combined load in these multiple directions. A configuration in which a load acts in one direction may be adopted.

Further, in the above embodiment, as the speed reducer, a so-called center crank type eccentric swing type speed reducer in which one shaft (input shaft) having an eccentric body is arranged at the shaft center of the speed reducer is shown. However, to the speed reducer of the present invention, a so-called distribution type eccentric swing type speed reducer in which two or more shafts having an eccentric body are arranged offset from the axis of the speed reducer may be applied. Further, in the above embodiment, an example in which an eccentric swing type speed reducer that swings the external gear is applied as the speed reducer is shown. However, as the speed reducer according to the present invention, an internal tooth swing type inscribed meshing planetary gear device in which the internal tooth gear swings and meshes with the external tooth gear may be applied. In this case, the swing gear corresponds to an internal gear.

Further, in the above embodiment, an example in which a permanent magnet type rotor is applied is shown, but any type of rotor may be applied as long as it is a rotor in which a load is generated by a rotating magnetic field. In addition, the details shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

1 Gear Motor M1 Motor G1 Reducer 3 Stator 3a, 3Aa, 3Ba Stator Core 3b, 3Ab, 3Bb Coil 4 Rotor Shaft 4a Rotor 4b1-4b8 Permanent Magnet 12 Input Shaft 14 Eccentric Body 22, 22A1, 22A2, 22B1-22B3 External Gear 26 Internal gear 26b External pin 28 Internal pin 29 Carrier body 31-35 1st to 5th casing 41, 42 Bearing 44 Main bearing Hr1, Hr11, Hr12, Hr21 to Hr23 Rotating magnetic field F1, F2, FA1 to FA4, FB1 to FB6 Load A1, A2 fulcrum

Claims (4)

A gear motor equipped with a motor and a speed reducer.
The motor has a stator in which a coil is wound and a rotor shaft having a rotor.
The speed reducer has an input shaft that rotates coaxially with the rotor shaft, an eccentric body provided on the input shaft, and a swing gear that swings by the eccentric body.
The phase of the eccentric body and the phase of the rotating magnetic field of the motor so that the load acting on the rotor shaft due to the rotating magnetic field of the motor is generated in the direction of canceling the load acting on the input shaft due to the rotation of the eccentric body. Is adjusted so that the motor and the speed reducer are connected.
Gear motor. The number of the oscillating gears is one,
The load acting on the rotor shaft due to the rotating magnetic field of the motor and the load acting on the input shaft due to the rotation of the eccentric body are adjusted in opposite directions.
The gear motor according to claim 1. The input shaft is not bearing on the opposite side of the rotor shaft from the eccentric body.
The gear motor according to claim 1 or 2. The input shaft is provided with a plurality of the eccentric bodies having different positions in the axial direction.
The motor generates multiple rotating magnetic fields of different sizes and directions.
The gear motor according to claim 1 or 3.

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