gear motor

Abstract

This gear motor (1) comprises a motor (20) and a reducer (30). The reducer (30) is a magnetic shift gear. Accordingly, contactless power transmission is possible due to magnetic force, and thus, a lubricant is not necessary for the reducer (30) and it is possible to achieve a simple structure.

Description

[Technical Field]

[0001] The present invention relates to a gear motor. [Background technology]

[0002] BACKGROUND ART Conventionally, a gear motor including a motor and a reducer has been known (see, for example, Patent Document 1). Generally, a gear motor consists of a motor and a mechanical gear reducer arranged side by side in the axial direction, as shown in Figure 6. The motor and reducer are separated by a partition wall to prevent the lubricant in the reducer from entering the motor, and the reducer is equipped with multiple oil seals that seal in lubricating oil. In addition, the motor and reducer have their respective shafts supported by multiple bearings so that they can each function as a single rotating machine. As described above, conventional gear motors have a complex structure, making it difficult to reduce the number of parts and make them more compact. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3916337 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in view of the above circumstances, and has as its object to simplify the structure. [Means for solving the problem]

[0005] The present invention provides a gear motor including a motor including a rotor and a stator, and a reducer, the reducer is a magnetic modulation gear, an input shaft having a plurality of inner pole magnets arranged in a circumferential direction; a plurality of magnetic pole pieces arranged on the outer diameter side of the input shaft and arranged in a circumferential direction; a plurality of outer pole magnets arranged on the outer diameter side of the plurality of magnetic pole pieces and arranged in a circumferential direction; Equipped with The rotation of the rotor of the motor is input to the magnetic modulation gear, the magnetic modulation gear The magnetic modulation gear is decelerated by The output rotation is transmitted to the output member. [Effects of the Invention]

[0006] According to the present invention, the structure can be simplified. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a gear motor according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a reducer included in the gear motor according to the present embodiment. [Figure 3] FIG. 10 is a cross-sectional view showing a gear motor according to a modified example of the present embodiment. [Figure 4] FIG. 10 is a cross-sectional view showing a gear motor according to another modified example of the present embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing a gear motor according to another modified example of the present embodiment. [Figure 6] FIG. 1 is a cross-sectional view of a conventional gear motor. BEST MODE FOR CARRYING OUT THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0009] [Gear motor configuration] FIG. 1 is a cross-sectional view of a gear motor 1 according to this embodiment. As shown in this figure, the gear motor 1 according to this embodiment includes a motor 20 and a reducer 30, which are housed in a common casing (frame) .

[0010] <Motor> The motor 20 includes a motor rotor 21 and a motor stator 22 . The motor rotor 21 has a shaft 21a, a rotor yoke 21b, and a rotor magnet 21c. The rotor yoke 21b is made of a magnetic material and is fitted and fixed to the outer circumferential surface of the shaft 21a. The rotor magnet 21c is a permanent magnet such as a neodymium magnet, and a plurality of rotor magnets corresponding to a predetermined number of poles are attached to a portion of the outer circumferential surface of the rotor yoke 21b that is located on the inner diameter side of the motor stator 22. In the following description, the direction along the central axis Ax of the shaft 21a is referred to as the "axial direction," the direction perpendicular to the central axis Ax is referred to as the "radial direction," and the direction of rotation about the central axis Ax is referred to as the "circumferential direction." In addition, in the axial direction, the side that is connected to an external driven member (the left side in the drawing) is referred to as the "load side," and the side opposite the load side (the right side in the drawing) is referred to as the "anti-load side."

[0011] The motor rotor 21 is supported by two bearings (for example, ball bearings) 12a and 12b that support the shaft 21a. Of these, the anti-load side bearing 12a is disposed between the shaft 21a and an anti-load side cover 11 fixed to the casing 10. The anti-load side cover 11 is fixed to the casing 10 so as to cover the anti-load side of the motor stator 22, and rotatably supports the shaft 21a (motor rotor 21) via the bearing 12a. On the other hand, the load-side bearing 12b is disposed between a low-speed rotor 32 (output member 32b) of the reducer 30 (described later) and the shaft 21a, on the load side of the reducer 30. The low-speed rotor 32 and the shaft 21a are capable of relative rotation via the bearing 12b.

[0012] The motor stator 22 is configured by winding a coil 22b around a stator core 22a made of laminated steel plates. The motor stator 22 is concentrically disposed on the outer diameter side of the motor rotor 21, and is held by the casing 10 with the stator core 22a fitted inside the casing 10.

[0013] <Reducer> The reducer 30 is disposed on the load side of the motor 20, and reduces the speed of the rotation input from the motor 20 and outputs it to the load side. The reducer 30 and the motor 20 share a common shaft (the motor rotor 21 and the high-speed rotor 31), and there is no partition between them, such as a partition wall. Specifically, the reducer 30 is a magnetic modulation gear, and includes a high-speed rotor (input shaft) 31, a low-speed rotor (output shaft) 32, and an outer pole magnet 33.

[0014] FIG. 2 is a perspective view of the reducer 30. As shown in FIG. As shown in FIGS. 1 and 2 , the high-speed rotor 31 includes a shaft 21a and a rotor yoke 21b, which are common to the motor rotor 21 of the motor 20, and an internal magnet 31a. The shaft 21a and the rotor yoke 21b extend axially from the motor 20 to the reducer 30. Both axial ends of the shaft 21a extend from the rotor yoke 21b, and these end ends are supported by the bearings 12a and 12b. The internal magnet 31a is a permanent magnet, such as a neodymium magnet, and is attached to the outer circumferential surface of the rotor yoke 21b so that multiple magnets with different polarities are arranged alternately in the circumferential direction. The internal magnet 31a forms magnetic poles that do not contribute to torque generation of the motor 20. The number of poles may be the same as or different from the number of field poles of the motor 20. The internal magnet 31a may be a single ring-shaped magnet, or may be divided and arranged in the circumferential direction. Preferably, the high-speed rotor 31 is configured integrally with the motor rotor 21, and more preferably shares at least one shaft part with the motor rotor 21. The rotor yoke of the reducer 30 may be separate from the rotor yoke 21b of the motor 20 (see FIG. 4).

[0015] In this embodiment, the low-speed rotor 32 is formed in a stepped cylindrical shape and is arranged concentrically with the high-speed rotor 31. The low-speed rotor 32 has magnetic pole pieces 32a arranged on the outer diameter side of the internal pole magnets 31a. The magnetic pole pieces 32a are made of laminated steel plates, and a plurality of them are arranged at predetermined intervals in the circumferential direction. The number of magnetic pole pieces 32a is the number of outer pole pairs (the number of pole pairs of the outer pole magnets 33) ± the number of inner pole pairs (the number of pole pairs of the inner pole magnets 31a), and is generally the number of outer pole pairs + the number of inner pole pairs. Two circumferentially adjacent magnetic pole pieces 32a may be connected by a thin connecting portion or a non-magnetic material. The low-speed rotor 32 also has an output member 32b connected to the load side of the pole piece 32a. More specifically, resin portions 32c are fixed to both axial ends of the pole piece 32a, and the output member 32b is fixed to the load-side resin portion 32c with bolts 32d (made of, for example, super engineering plastic). The bolts 32d may be fixed radially rather than axially, or may be integrally molded with the resin portion 32c. The load-side end of the output member 32b is exposed from the casing 10 and is connected to a driven member (not shown). The low-speed rotor 32 is rotatably supported by the casing 10 via a bearing 32e provided on the anti-load side of the pole piece 32a and a bearing 32f provided on the load side of the pole piece 32a. The anti-load side bearing 32e is disposed between the casing 10 and a stainless steel ring member 32g fixed to the anti-load side resin portion 32c of the pole piece 32a. On the other hand, the load-side bearing 32f is disposed between the load-side cover 13 fixed to the load-side end of the casing 10 and the output member 32b.

[0016] The outer magnet 33 is concentrically arranged on the outer diameter side of the pole piece 32a with a predetermined gap therebetween. This outer magnet 33 has more poles than the inner magnet 31a of the high-speed rotor 31, and is a stator attached to the inner peripheral surface of the casing 10 via a yoke portion 33a (not shown in FIG. 2) so that multiple magnets with different polarities are arranged alternately in the circumferential direction. The outer magnet 33 may be a single ring-shaped magnet, or may be divided and arranged in the circumferential direction.

[0017] [Gear motor operation] In the gear motor 1, when the coil 22b of the motor 20 is energized and the motor stator 22 generates a rotating magnetic field, a rotational torque acts on the rotor magnet 21c, causing the motor rotor 21 to rotate around the central axis Ax. As a result, the high-speed rotor 31 of the reducer 30, which is formed integrally with the motor rotor 21, also rotates, and rotation is input to the reducer 30. When the high-speed rotor 31 rotates, the spatial magnetic flux waveform of the internal pole magnet 31a of the high-speed rotor 31 is modulated by the magnetic pole piece 32a of the low-speed rotor 32 to the same frequency as the external pole magnet 33, and rotational torque is transmitted to the low-speed rotor 32 using the magnetic force between the magnetic pole piece 32a and the external pole magnet 33. At this time, the reduction ratio is (number of magnetic pole pieces / number of pole pairs of the internal pole magnet).

[0018] [Technical effect of this embodiment] As described above, according to the gear motor 1 of this embodiment, the reducer 30 is a magnetic modulation gear, which enables contactless power transmission by magnetic force and eliminates the need for lubricant in the reducer 30. This eliminates the need for a partition wall separating the motor 20 and the reducer 30, and also eliminates oil seals from the anti-load side cover 11 and the load side cover 13. This simplifies the structure. In addition, by eliminating the oil seal, the gear motor has a structure that does not have any parts that come into sliding contact with the shaft, and does not inhibit the circulation of fluid inside and outside the gear motor 1. Furthermore, by eliminating the oil seal, friction loss can be reduced and noise can be reduced, and there is no need to replace the oil seal itself or the oil, which reduces costs. In addition, because lubricant is no longer necessary, the gear motor can be suitably applied in environments where clean operation is required.

[0019] Furthermore, according to the gear motor 1 of this embodiment, the motor rotor (output shaft) 21 of the motor 20 and the high-speed rotor (input shaft) 31 of the reducer 30 are integrally constructed, which eliminates the need to process the connecting portion of these shafts. This makes it possible to reduce the number of parts and make the device more compact, which means that the structure can be further simplified.

[0020] Furthermore, according to the gear motor 1 of this embodiment, the motor rotor 21 of the motor 20 and the high-speed rotor 31 of the reducer 30 are supported by a bearing 12b arranged on the load side of the reducer 30 and a bearing 12a arranged on the anti-load side of the motor 20. That is, due to the compact design, the shaft can be supported by only two bearings 12a and 12b that straddle the motor 20 and the reducer 30. Therefore, compared to the conventional design in which the shaft was supported by multiple bearings, the number of bearings can be reduced, simplifying the structure and reducing bearing loss.

[0021] In addition, the gear motor 1 of this embodiment is provided with two bearings 12a, 12b that support the motor rotor 21 of the motor 20 and the high-speed rotor 31 of the reducer 30, and two bearings 32e, 32f that support the low-speed rotor (output shaft) 32 of the reducer 30. In other words, four bearings are sufficient for the entire gear motor 1.

[0022] [Variation 1] FIG. 3 is a cross-sectional view showing a gear motor 1A according to a modified example of the above embodiment. In the above embodiment, the rotor magnet 21c of the motor 20 and the internal magnet 31a of the reducer 30 form magnetic poles that are independent of each other. However, the field poles of the motor 20 and the magnetic poles of the high-speed rotor 31 of the reducer 30 may be common. For example, as shown in Fig. 3, in a gear motor 1A according to this modification, the motor 20 is an induction machine, and instead of the rotor yoke 21b in the above embodiment (or on its outer diameter side), a rotor core 21d made of laminated steel plates is provided from the inner diameter side of the motor stator 22 to the inner diameter side of the magnetic pole pieces 32a. Multiple axially extending conductor bars (secondary conductors) 21e are embedded circumferentially in the rotor core 21d, and both axial ends of the conductor bars are connected by end rings 21f. This allows the field poles of the motor 20 and the magnetic poles of the high-speed rotor 31 of the reducer 30 to be common.

[0023] [Variation 2] FIG. 4 is a cross-sectional view showing a gear motor 1B according to another modified example of the above embodiment. The gear motor 1B according to this modification differs from the above embodiment mainly in that it includes a partition wall that separates the motor 20 and the reducer 30. The following mainly describes this difference, and the same components as those in the above embodiment are denoted by the same reference numerals and their description is omitted.

[0024] As shown in FIG. 4, in the gear motor 1B, the casing (frame) is divided into a motor casing 10M that houses the motor 20 and a reducer casing 10G that houses the reducer 30. The motor casing 10M and the reducer casing 10G are fixed to a partition wall 14 that separates the motor 20 and the reducer 30 from each other.

[0025] Furthermore, in the gear motor 1B, unlike the above-described embodiment, the motor 20 and the reducer 30 do not share a common shaft, but are divided into a motor shaft 21g for the motor 20 and a reducer shaft 31b for the reducer 30. The motor shaft 21g and the reducer shaft 31b are coupled (fitted) to enable power transmission. The motor shaft 21g is rotatably supported by a bearing 12c provided on the inner periphery of the partition wall 14. Furthermore, unlike the above-described embodiment, the high-speed rotor 31 of the reducer 30 has a rotor yoke 31c that is separate from the rotor yoke 21b of the motor 20.

[0026] In this way, the motor 20 and the reducer 30 may be separated by the partition wall 14. Even with this configuration, the same effects as those of the above embodiment can be obtained. That is, because the reducer 30 is a magnetic modulation gear, contactless power transmission is possible using magnetic force, eliminating the need for lubricant in the reducer 30. This allows oil seals to be eliminated from the non-load side cover 11, the load side cover 13, and the partition wall 14. This simplifies the structure. Furthermore, elimination of oil seals not only reduces friction loss and noise, but also eliminates the need to replace the oil seals themselves or the oil, reducing costs. Furthermore, because no lubricant is required, the reducer 30 can be suitably applied in environments where clean operation is required.

[0027] 5, a partition wall separating the motor 20 and the reducer 30 may be provided on each of the motor 20 and the reducer 30. Specifically, this gear motor 1C includes a partition wall 14M on the motor 20 side and a partition wall 14G on the reducer 30 side. The partition wall 14M on the motor 20 side is fixed to a motor casing 10M. The partition wall 14M rotatably supports a motor shaft 21g via a bearing 12d provided on the inner periphery. On the other hand, the partition wall 14G on the reducer 30 side is fixed to a reducer casing 10G. The partition wall 14G rotatably supports a reducer shaft 31b via a bearing 12e provided on the inner periphery. These partition walls 14M and 14G are fitted together so that they can be centered with desired accuracy by means of a spigot portion R. Furthermore, the partition walls 14M and 14G each have a flange portion (not shown) that protrudes from the outer periphery, and are fixed to each other by a fastening bolt that is inserted into the flange portion. With this structure, the motor 20 and the reducer 30 can be configured to be detachable.

[0028] [others] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, the type and structure of the motor 20 are not particularly limited, and as described above, it may be a synchronous machine, an induction machine, a DC machine, or the like. Furthermore, in the reducer 30 of the above embodiment, the external pole magnet 33 is used as the stator, and output is extracted from the low-speed rotor 32 having the pole pieces 32a. However, the pole pieces 32a may be fixed, and the external pole magnet 33 may be provided on a rotatable low-speed rotor, and output may be extracted from the low-speed rotor.

[0029] In addition, the details shown in the above embodiment can be modified as appropriate without departing from the spirit of the invention.

[0030] As described above, the gear motor according to the present invention is useful for simplifying the structure. [Explanation of symbols]

[0031] 1, 1A, 1B, 1C gear motor 10 Casing 10G reducer casing 10M motor casing 11 Anti-load side cover 12a~12e Bearings 13 Load side cover 14, 14G, 14M Bulkhead 20 Motor 21 Motor rotor 21a shaft 21b Rotor yoke 21c rotor magnet 21d rotor core 21e Conductor bar 21f End Ring 21g motor shaft 22 Motor stator 30 Reducer 31 High-speed rotor 31a Inner pole magnet 31b Reducer shaft 32 Low-speed rotor 32a pole piece 32b Output member 32e, 32f bearings 33 outer pole magnet Ax center axis

Claims

1. A gear motor including a motor including a rotor and a stator, and a reducer, the reducer is a magnetic modulation gear, an input shaft having a plurality of inner pole magnets arranged in a circumferential direction; a plurality of magnetic pole pieces arranged on the outer diameter side of the input shaft and arranged in a circumferential direction; a plurality of outer pole magnets arranged on the outer diameter side of the plurality of magnetic pole pieces and arranged in a circumferential direction; Equipped with The rotation of the rotor of the motor is input to the magnetic modulation gear, The output rotation of the magnetic modulation gear reduced by the magnetic modulation gear is rotationally transmitted to an output member. Gear motor.

2. The number of magnetic poles of the inner magnet is different from the number of field poles of the motor.

2. The gear motor according to claim 1.

3. cover members disposed on both axial sides of the motor and the reducer; No oil seal is disposed on the cover member.

3. The gear motor according to claim 1 or 2.

4. The output shaft of the motor and the input shaft of the reducer share at least one shaft part. The gear motor according to any one of claims 1 to 3.

5. There is no partition between the motor and the reducer. A gear motor according to any one of claims 1 to 4.

6. a partition wall separating the motor and the reducer; The gear motor according to any one of claims 1 to 3.

7. an output shaft of the motor and an input shaft of the reducer are supported by a bearing disposed on the load side of the reducer and a bearing disposed on the anti-load side of the motor; A gear motor according to any one of claims 1 to 6.

8. two bearings supporting the output shaft of the motor and the input shaft of the reducer, and two other bearings supporting the output shaft of the reducer; A gear motor according to any one of claims 1 to 7.

9. The field poles of the motor and the magnetic poles of the input shaft of the reducer are common to each other. A gear motor according to any one of claims 1 to 8.

10. a magnetic pole that does not contribute to torque generation of the motor is formed on the input shaft of the reducer; A gear motor according to any one of claims 1 to 8.

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