Speed reduction device and electrical apparatus

Abstract

The thickness of the entire structure can be further reduced while achieving a high reduction ratio. The reduction device has a motor and a reduction component, the motor and the reduction component are arranged in an axial direction, the reduction component has a first gear arranged on a side of the first motor housing away from the motor, a second gear engaged with the first gear, and a third gear engaged with the second gear, the first gear, the second gear, and the third gear are located on one side of the first motor housing in the axial direction, the reduction component has at least one bearing arranged on the radially inner side of the first gear, the first gear is at least one, and the second gear and the third gear each include two gears arranged adjacent to each other in the axial direction. Therefore, the thickness of the entire structure in the axial and radial directions can be further reduced while achieving a high reduction ratio.

Description

TECHNICAL FIELD

[0001] The present application relates to a speed reduction device and an electric apparatus. This application claims priority based on Japanese Patent Application No. 2020-159870 filed in Japan on September 24, 2020, the contents of which are incorporated herein. BACKGROUND

[0002] In the past, there has been a technology of combining a motor and a speed reducer. The general combination of a motor and a speed reducer is a configuration in which the speed reducer is directly connected to the motor. An actuator obtained by combining a motor and a speed reducer is a main component for robot applications. In order to output a large torque, it is necessary for the speed reducer to have a high reduction ratio so as to convert a high-speed low-torque output of the motor into a low-speed high-torque output.

[0003] Generally, a speed reducer having a high reduction ratio uses a multi-stage planetary gear device that is long in the axial direction, and thus the device is large-sized. For example, in Patent Documents 1 and 2 described below, a speed reducer having a multi-stage planetary gear device is proposed. According to this device, a high reduction ratio can be obtained.

[0004] In addition, for example, in Patent Document 3 described below, a speed reducer having a two-stage planetary gear device is proposed, and by using a two-stage gear device, a greatly improved reduction ratio can be obtained.

[0005] Also, for example, in Patent Document 4 described below, a structure is proposed in which a motor has a space in the center and a speed reducer is installed in the space. In this technology, the device as a whole is designed to be thin in the axial direction.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT DOCUMENTS

[0008] Patent Document 1: U.S. Patent No. 8829750

[0009] Patent Document 2: Chinese Patent Publication No. 103545981

[0010] Patent Document 3: U.S. Patent Publication No. 20110009232

[0011] Patent Document 4: Chinese Patent Publication No. 101258664 SUMMARY

[0012] PROBLEMS TO BE SOLVED BY THE INVENTION

[0013] However, in the technology of simply combining the reducer with the multi-stage planetary gear device of Patent Documents 1 and 2 or the reducer with the double-stage planetary gear device of Patent Document 3 with the motor, although a higher reduction ratio can be obtained, there is a problem of axial enlargement of the entire device. On the other hand, in Patent Document 4, in order to house the reducer in the space of the motor, the outer diameter of the motor is increased.

[0014] The present application was achieved in view of the above-described circumstances, and aims to further reduce the thickness of the entire configuration while achieving a high reduction ratio (high output torque).

[0015] Means for solving the problem

[0016] The reduction device of one embodiment of the present application includes a motor including first and second rotary shafts that rotate about a center axis, a first rotor disposed radially outward of the first rotary shaft, a second rotor disposed radially outward of the second rotary shaft, a stator disposed between the first rotor and the second rotor, a first motor case disposed on an axial side of the first rotor away from the stator, and a second motor case disposed on an axial side of the second rotor away from the stator, and a reduction member including a first gear disposed on an axial side away from the first motor case and rotating about the center axis, a second gear engaged with the first gear, a third gear engaged with the second gear, the second gear being mounted to a rotary shaft so as to be able to rotate about the rotary shaft, the third gear driving rotation of the second gear, the second gear driving an output shaft, and a carrier disposed between the output shaft and the first rotary shaft, the motor including at least one bearing disposed radially outward of the first rotary shaft, the bearing being positioned between the first rotor and the first motor case, the reduction member including at least one bearing disposed radially inward of the first gear, the first gear including two gears disposed axially adjacent to each other, and the second and third gears each including two gears disposed axially adjacent to each other.

[0017] The first gear can include two gears disposed axially adjacent to each other.

[0018] The reduction member can include a first ring member disposed between the third gear and the first motor case, the first ring member being in contact with one end of the rotary shaft, and a second ring member disposed between the third gear and the output shaft, the second ring member being in contact with the other end of the rotary shaft.

[0019] The second rotating shaft has a through hole extending in the axial direction, and a connecting member for connecting the first rotating shaft and the second rotating shaft is provided in the through hole.

[0020] The first motor housing can also have a second end portion connected to the first end portion on the other axial side close to the first rotor. The bearing of the speed reduction member can also include a second bearing between the first ring member and the first motor housing. The circumferential surface on the radially inner side of the second bearing can be opposite to the second end portion in the radial direction.

[0021] The first motor housing can also have a second end portion connected to the first end portion on the other axial side close to the first rotor. The bearing of the speed reduction member can also include a second bearing between the first ring member and the first motor housing. The circumferential surface on the radially inner side of the second bearing can be opposite to the second end portion in the radial direction.

[0022] According to another embodiment of the present application, the motor has a bearing on the other axial side of the second rotating shaft away from the first rotating shaft. The second motor housing has a protrusion protruding toward the one axial side. The end portion of the second rotating shaft on the other axial side has a recess. The bearing is arranged between the inner circumferential surface of the recess and the outer circumferential surface of the protrusion.

[0023] Preferably, the number of the second gears is at least two or more. The two or more second gears are arranged in the circumferential direction around the center axis.

[0024] Preferably, the first gear is a ring gear, the second gear is a planetary gear, and the third gear is a sun gear.

[0025] Preferably, the motor is an axial flux motor.

[0026] Preferably, the speed reduction member further has a bearing arranged on the radially outer side of the output shaft.

[0027] According to another embodiment of the present application, the positioning portion can be provided between two second gears arranged adjacent to each other in the axial direction.

[0028] According to another embodiment of the present application, the radially outermost end of the first gear can be located on the radially inner side than the radially outermost end of the first motor housing.

[0029] According to another embodiment of the present application, one end of the wheel carrier can be connected to the first rotating shaft, and the other end of the wheel carrier can be connected to the third gear.

[0030] According to another embodiment of the present application, one end of the wheel carrier can be connected to the first rotating shaft and the other end can be connected to the rotating shaft.

[0031] An electrical device having a speed reduction device of one embodiment of the present application can be provided.

[0032] Effects of Invention

[0033] A speed reduction device of one embodiment of the present application includes a motor and a speed reduction member. The motor and the speed reduction member are arranged in an axial direction. The speed reduction member includes a first gear arranged on a side of a first motor case away from the motor, a second gear engaged with the first gear, and a third gear engaged with the second gear. The first gear, the second gear, and the third gear are arranged on one side of the first motor case in the axial direction. The speed reduction member includes at least one bearing arranged on an inner side of the first gear in a radial direction. The first gear is at least one. The second gear and the third gear each include two gears arranged adjacent to each other in the axial direction. Thus, a high reduction ratio can be achieved while reducing the thickness of the entire structure in the axial and radial directions. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 FIG. 1 is a perspective view of a speed reduction device of a first embodiment, showing a state in which a speed reduction member is separated from a motor.

[0035] Figure 2 FIG. 2 is a cross-sectional view of a structure of the first embodiment, showing a state in which the speed reduction member is separated from the motor.

[0036] Figure 3 FIG. 3 is a cross-sectional view of a structure of a first rotating shaft and a second rotating shaft.

[0037] Figure 4 FIG. 4 is a cross-sectional view of a structure of the first embodiment.

[0038] Figure 5 FIG. 5 is a diagram of a planetary gear train of the speed reduction member of the first embodiment.

[0039] Figure 6 FIG. 6 is a perspective view of a structure of a part of the speed reduction member of the first embodiment.

[0040] Figure 7A FIG. 7 is a top view of a part of the speed reduction member of the first embodiment, showing a structure of a first-stage planetary gear train.

[0041] Figure 7B FIG. 8 is a top view of a part of the speed reduction member of the first embodiment, showing a structure of a second-stage planetary gear train.

[0042] Figure 8is a modification of the first embodiment of the speed reduction device, and is a perspective view showing a state in which the speed reduction member is separated from the motor.

[0043] Figure 9 is a sectional view showing a structure of the modification of the first embodiment.

[0044] Figure 10 is a sectional view showing a structure of the second embodiment of the speed reduction device.

[0045] Figure 11 is a diagram showing a planetary gear train of the speed reduction member of the second embodiment.

[0046] Figure 12 is a sectional view showing a structure of the modification of the second embodiment of the speed reduction device.

[0047] Figure 13 is a sectional view showing a structure of the third embodiment of the speed reduction device.

[0048] Figure 14 is a diagram showing a planetary gear train of the speed reduction member of the third embodiment.

[0049] Figure 15 is a sectional view showing a structure of the modification of the third embodiment of the speed reduction device.

[0050] Figure 16 is a sectional view showing a structure of the fourth embodiment of the speed reduction device.

[0051] Figure 17 is a diagram showing a planetary gear train of the speed reduction member of the fourth embodiment.

[0052] Figure 18 is a sectional view showing a structure of the modification of the fourth embodiment of the speed reduction device. DETAILED DESCRIPTION

[0053] Reference Figures 1-18 Embodiments of a speed reduction device will be described as examples of the present application. Hereinafter, a radial direction with respect to a center axis of first and second rotation shafts of a motor will be referred to as "radial direction", a direction around the center axis will be referred to as "circumferential direction", and an extending direction of the center axis and a direction parallel to the center axis will be referred to as "axial direction". In addition, in the axial direction, a direction in which the motor is directed toward a speed reduction member will be referred to as "front direction", and a direction opposite to the "front direction" will be referred to as "rear direction".

[0054]

First Embodiment

[0055] As Figure 1As shown, the reduction gear 100 of the present invention is a first example of a reduction gear, and includes a motor 1 and a reduction member 2. In the illustrated example, the motor 1 and reduction member 2 are separated. Then, the motor 1 and reduction member 2 are axially integrated by bolts 34 to form the reduction gear 100.

[0056] like Figure 2 As shown, the motor 1 includes a first rotating shaft 16 and a second rotating shaft 17 that rotate about a center axis C indicated by a dashed line; a first rotor 14 disposed radially outward of the first rotating shaft 16; a second rotor 15 disposed radially outward of the second rotating shaft 17; a stator 11 disposed between the first and second rotors 14, 15; a first motor housing 12 disposed on one axial side of the first rotor 14 away from the stator 11; a second motor housing 13 disposed on the other axial side of the second rotor 15 away from the stator 11; and a single bearing 18 disposed radially outward of the first rotating shaft 16. The motor 1 has two rotors and is sometimes referred to as a dual-rotor motor in this specification.

[0057] exist Figure 2 In the example shown in FIG. 1 , the first motor housing 12 is located in front of the stator 11, and the second motor housing 13 is located behind the stator 11, with the stator 11 as the boundary. The first rotor 14 is located in front of the stator 11 and between the stator 11 and the first motor housing 12. Furthermore, the second rotor 15 is located behind the stator 11 and between the stator 11 and the second motor housing 14. A bearing 18 is located axially between the first rotor 14 and the first motor housing 12. The first rotor 14 and the second rotor 15 shown in this embodiment are, for example, disc-shaped disc rotors.

[0058] In this embodiment, the motor 1 and the deceleration member 2 are arranged along the axial direction. The deceleration member 2 is provided on the front side of the motor 1 . For example, the deceleration member 2 is located on the front side of the first motor housing 12 .

[0059] The first motor housing 12 has a first end 120 on one axial side away from the first rotor 14 and a second end 121 connected to the first end 120 on the other axial side close to the first rotor 14. The first rotating shaft 16 is located radially inside the first and second ends 120, 121.

[0060] In this embodiment, bearing 18 is located between second end portion 121 and first rotating shaft 16. In this embodiment, first rotating shaft 16 and second rotating shaft 17 are rotatably supported by a single bearing 18 in first motor housing 12. This allows for a greater space to be created in front of first motor housing 12, compared to, for example, a case where multiple bearings are provided in front of stator 11.

[0061] like Figure 3As shown in FIG. 1, the second rotary shaft 17 has a through-hole 170 that penetrates through in the axial direction. The through-hole 170 is located on the rear side of the second rotary shaft 17 in the axial direction. A connecting member 50 for connecting the first rotary shaft 16 and the second rotary shaft 17 is provided in the through-hole 170. The connecting member 50 is, for example, a bolt. The connecting member 50 is not limited to a bolt, but can be a member other than a bolt.

[0062] As shown in FIG. 1, the first rotary shaft 16 has a first hole 160 and a second hole 161. The first hole 160 is located on the rear side of the first rotary shaft 16 in the axial direction, toward the second rotary shaft 17 side. The second hole 161 is located on the front side of the first rotary shaft 16 in the axial direction, toward the reduction member 2 side. Both the first hole 160 and the second hole 161 are, for example, internally threaded holes having internal threads. Figure 2 Figure 3 When the first rotary shaft 16 and the second rotary shaft 17 are connected, the connecting member 50 is inserted from the through-hole 170 and is threadedly fastened in the first hole 160, thereby connecting the first rotary shaft 16 and the second rotary shaft 17, and a combined rotary shaft in which the two rotary shafts are combined can be formed. The first rotary shaft 16 and the second rotary shaft 17 can also be hollow. Thus, the weight of the first rotary shaft 16 and the second rotary shaft 17 can be reduced. The combined rotary shaft referred to in the present specification means a rotary shaft in which two rotary shafts are combined in a manner connected in the axial direction.

[0063] A connecting member 34 for connecting the above-mentioned combined rotary shaft and the reduction member 2 is provided in the second hole 161. The connecting member 34 is, for example, a bolt. The connecting member 34 is not limited to a bolt, but can be a member other than a bolt. The connecting member 34 is inserted into the second hole 161 from the reduction member 2 side and is threadedly fastened, thereby connecting the combined rotary shaft and the reduction member 2. Thus, a reduction device 100 in which the motor 1 and the reduction member 2 are integrated is constituted.

[0064] A connecting member 34 for connecting the above-mentioned combined rotary shaft and the reduction member 2 is provided in the second hole 161. The connecting member 34 is, for example, a bolt. The connecting member 34 is not limited to a bolt, but can be a member other than a bolt. The connecting member 34 is inserted into the second hole 161 from the reduction member 2 side and is threadedly fastened, thereby connecting the combined rotary shaft and the reduction member 2. Thus, a reduction device 100 in which the motor 1 and the reduction member 2 are integrated is constituted. Figure 3 As shown in FIG. 1, the motor 1 and the reduction member 2 become the reduction device 100.

[0065] Next, the structure of the reduction member 2 will be described in detail. As shown in FIG. 2, the reduction member 2 has two first gears 21, 23 disposed on the side of the first motor housing 12 away from the motor 1 in the axial direction, two second gears 22, 24 engaged with the first gears 21, 23, two third gears 30, 31, an output shaft 25 driven in rotation by the second gears 22, 24 and driving the second gears 22, 24 in rotation by the third gears 30, 31 (in the present embodiment, the second gear 24), a rotary shaft 26, and a carrier 32 disposed between the output shaft 25 and the first rotary shaft 16. Figure 4 As shown in FIG. 2, the reduction member 2 has two first gears 21, 23 disposed on the side of the first motor housing 12 away from the motor 1 in the axial direction, two second gears 22, 24 engaged with the first gears 21, 23, two third gears 30, 31, an output shaft 25 driven in rotation by the second gears 22, 24 and driving the second gears 22, 24 in rotation by the third gears 30, 31 (in the present embodiment, the second gear 24), a rotary shaft 26, and a carrier 32 disposed between the output shaft 25 and the first rotary shaft 16.

[0066] Figure 5 ​​As shown, the reduction member 2 has two-stage planetary gear trains PGT1, PGT2. The planetary gear trains PGT1, PGT2 each include three gears. Specifically, the planetary gear train PGT1 includes a first gear 21, a second gear 22, and a third gear 30. The planetary gear train PGT2 includes a first gear 23, a second gear 24, and a third gear 31.

[0067] The planetary gear trains PGT1 and PGT2 are located Figure 4 The planetary gear trains PGT1 and PGT2 are located

[0068] The two first gears 21, 23 are arranged adjacent to each other in the axial direction. In the present embodiment, the first gear 21 of the two first gears 21, 23 is fixed to the first motor housing 12, and the first gear 23 is connected to the output shaft 25. In addition, the two second gears 22, 24 are arranged adjacent to each other in the axial direction. The two second gears 22, 24 are each mounted on the rotating shaft 26 by a bearing 27. Also, the two third gears 30, 31 are arranged adjacent to each other in the axial direction. The two third gears 30, 31 are mounted on the carrier 32 by bolts 33, and are integrally configured as a common gear. The reduction member 2 shown in the present embodiment is configured as a two-stage planetary gear device, and thus can achieve a higher reduction ratio than a one-stage planetary gear device.

[0069] The reduction member 2 has a first ring member 28 arranged between the third gear 30 and the first motor housing 12, and a second ring member 29 arranged between the third gear 31 and the output shaft 25. The first ring member 28 is in contact with one end of the rotating shaft 26 of the third gear, and the second ring member 29 is in contact with the other end of the rotating shaft 26. That is, the rotating shaft 26 is fixed by the first ring member 28 and the second ring member 29. The rotating shaft 26 is integrally configured with the first ring member 28 and the second ring member 29. Thus, the rotating shaft 26 is stably mounted in the reduction member 2. The rotating shaft 26 is in a state of being integrated with the first ring member 28 and the second ring member 29, and becomes a common rotating shaft in the two-stage gear configuration of the present application.

[0070] The reduction member 2 has at least one bearing arranged radially inward of the first gear 21. In the present embodiment, the reduction member 2 has at least a first bearing 38 and a second bearing 39. The first bearing 38 is located radially inward of the third gears 30, 31. The second bearing 39 is located between the first ring member 28 and the first motor housing 13. Also, when the motor 1 is connected to the reduction member 2, the peripheral surface radially inward of the first bearing 38 is in radial opposition to the first end portion 120, and the peripheral surface radially inward of the second bearing 39 is in radial opposition to the second end portion 121.

[0071] The carrier 32 is connected to the first rotating shaft 16 via a connecting member 34. Therefore, the carrier 32 functions as an input shaft for inputting driving force to the speed reduction member 2. The carrier 32 can transmit the driving force of the motor 1 to the third gear 30, for example.

[0072] The radially outermost end 320 of the carrier 32 is positioned radially inward of the radially innermost end 250 of the output shaft 25. This prevents the carrier 32 from interfering with the rotation of the output shaft 25, further reducing the axial thickness of the reduction component 2. This further reduces the axial thickness of the reduction gear 100.

[0073] The reduction component 2 further includes a bearing 35 disposed radially outward of the output shaft 25, a housing 36 connected to the first gear 21, and a bearing 37 disposed radially inward of the output shaft 25. The output shaft 25 is rotatable within the bearing 35. The bearing 35 mounts the output shaft 25 to the housing 36 of the reduction component 2. The bearing 37 is supported by the wheel carrier 32.

[0074] In this embodiment, if Figure 4 As shown, one bearing 18 is located axially forward of the stator 11. Therefore, a large space surrounding the bearing 18 can be formed in front of the first motor housing 12 of the motor 1. This large space can effectively accommodate the first gears 21, 23, the second gears 22, 24, and the third gears 30, 31 of the reduction member 2. As a result, the motor 1 and the reduction member 2 are configured to be relatively small in the axial and radial directions.

[0075] Furthermore, in this embodiment, the front end side of the first motor housing 12 in the axial direction is supported by the first bearing 38 and the second bearing 39 of the speed reduction member 2. That is, Figure 2 The radially inner circumference of the first bearing 38 shown is radially opposed to the first end 120, and the radially inner circumference of the second bearing 39 is radially opposed to the second end 121. Since the motor 1 is connected to the reduction gear 2, the first motor housing 12 is supported by the bearing 18 on the motor 1 side and the first and second bearings 38 and 39 on the reduction gear 2 side. This improves the rigidity of the motor 1. This prevents vibration of the combined rotating shaft, thereby enhancing the stability of the combined rotating shaft and the overall stability of the reduction gear.

[0076] The motor 1 shown in this embodiment is preferably an axial flux motor. Since the motor 1 is short in the axial direction, the overall structure of the reduction gear 100 can be made more compact.

[0077] In this embodiment, if Figure 6As shown, the first gears 21, 23 are, for example, ring gears. The second gears 22, 24 are, for example, planetary gears. The third gears 30, 31 are, for example, sun gears.

[0078] The diameters of the two second gears, i.e., the second gear 22 and the second gear 24, of the present application are different. For example, the diameter of the second gear 22 is larger than the diameter of the second gear 24. In addition, the diameters of the second gear 22 and the second gear 24 can also be the same, not limited to the above-described structure.

[0079] As shown, the second gear 22 in the planetary gear train PGT1 can revolve around the third gear 30 with the central axis C as an axis at the radially inner periphery of the first gear 21, and can rotate around the rotation axis 26. In addition, the third gear 30 in the planetary gear train PGT1 can rotate or orbit with the central axis C as an axis together with the first rotation axis 16. Figure 7A As shown, the second gear 22 in the planetary gear train PGT1 can revolve around the third gear 30 with the central axis C as an axis at the radially inner periphery of the first gear 21, and can rotate around the rotation axis 26. In addition, the third gear 30 in the planetary gear train PGT1 can rotate or orbit with the central axis C as an axis together with the first rotation axis 16.

[0080] As shown, the second gear 22 in the planetary gear train PGT1 can revolve around the third gear 30 with the central axis C as an axis at the radially inner periphery of the first gear 21, and can rotate around the rotation axis 26. In addition, the third gear 30 in the planetary gear train PGT1 can rotate or orbit with the central axis C as an axis together with the first rotation axis 16. Figure 7B As shown, the second gear 24 in the planetary gear train PGT2 can revolve around the third gear 31 with the central axis C as an axis at the radially inner periphery of the first gear 23, and can rotate around the rotation axis 26. In addition, the third gear 31 in the planetary gear train PGT2 can rotate or orbit with the central axis C as an axis together with the first rotation axis 16. In addition, the first gears 21, 23, the second gears 22, 24, and the third gears 30, 31 are not limited to the above-described structure.

[0081] The second gears 22, 24 can also be fixed to the rotation axis 26. In addition, the front end of the rotation axis 26 can also be installed in the wheel carrier 32. Thus, the second gears 22, 24 can rotate around the rotation axis 26 in the wheel carrier 32 through a journal bearing or a roller bearing.

[0082] The number of each of the second gears 22, 24 can also be two or more, and the two or more second gears 22, 24 are arranged in a circumferential direction with the central axis C as a center. The number of each of the second gears 22, 24 can also be determined according to the reduction ratio required to be achieved by the reduction member 2. In one embodiment, the number of each of the second gears 22, 24 can be, for example, 4 to 10. In the present embodiment, the number of each of the second gears 22, 24 is 6.

[0083] Here, the speed of the wheel carrier 32 is determined by the planetary gear train PGT1 on the input side. In the planetary gear train PGT1, the speed of the wheel carrier 32 is determined by the second gear 22. Figure 4In the example of FIG. 1, the numbers of the third gear 30 (sun gear), the second gear 22 (planet gear), and the first gear 21 (ring gear) of the planetary gear system PGT1 are zl, z2, and z3, respectively, and the numbers of the third gear 31 (sun gear), the second gear 24 (planet gear), and the first gear 23 (ring gear) of the planetary gear system PGT2 are z4, z5, and z6, respectively. The reduction ratio in this case is determined by the following equation. However, the reduction ratio is determined by the numbers of the gears of the planetary gear systems PGT1 and PGT2.

[0084]

[0085] Thus, the reduction device 100 of the first embodiment has the dual rotor motor (motor 1) and the reduction member 2, the dual rotor motor and the reduction member 2 are arranged in the axial direction, the reduction member 2 has the first gear arranged on the side of the first motor case 12 away from the motor 1, the second gear engaged with the first gear, and the third gear engaged with the second gears 22 and 24, the first gear, the second gear, and the third gear are arranged on the outer side in the axial direction of the first motor case, and the reduction member 2 has at least one bearing arranged on the inner side in the radial direction of the first gear. Therefore, the dual rotor motor and the reduction device can be made compact in the axial and radial directions, and a reduction device having a small volume and a high driving capacity can be obtained.

[0086] In addition, since the first gear, the second gear, and the third gear each include two gears arranged adjacent to each other, a high reduction ratio can be achieved, and the thickness of the entire structure can be further reduced compared to the case of a multi-stage configuration in which three or more gears are overlapped.

[0087] In addition, in the reduction device 100, the third gears 30 and 31 are manufactured separately and assembled, or are manufactured as one member including the carrier 32. In addition, in the reduction device 100, the first gear 23 and the output shaft 25 are manufactured separately and assembled, or are manufactured as one member.

[0088]

Variations of the First Embodiment

[0089] Figure 8 The reduction device 100A illustrated in FIG. 2 is a variation of the reduction device 100, and has a motor 1A and a reduction member 2A. The motor 1A and the reduction member 2A are integrated by a connecting member 34 to constitute the reduction device 100A. Hereinafter, structures different from those of the reduction device 100 will be described, and the same reference numerals will be assigned to the same structures as those of the reduction device 100, and detailed descriptions thereof will be omitted.

[0090] The motor 1A has a first motor housing 12a, a second motor housing 13a, a bearing 18, a first rotary shaft 16a, and a second rotary shaft 17a, and has a bearing 19 on the other axial side of the second rotary shaft 17a from the first rotary shaft 16a. The first motor housing 12a has an end portion 122 protruding toward the other axial side from the first rotor 14. The second motor housing 13a has a protrusion 130 protruding toward the one axial side, and the end portion of the second rotary shaft 17a on the other axial side has a recess 171. The bearing 19 is disposed between the inner peripheral surface of the recess 171 and the end surface of the protrusion 130.

[0091] In the motor 1A, the rotary shafts are supported by the two bearings 18, 19. That is, the second rotary shaft 17a on the rear side (rearward side) is supported by the bearing 19, and the first rotary shaft 16a on the front side (forward side) is supported by the bearing 18, and thus the rigidity of the motor can be improved. Also, the combined rotary shaft and the speed reduction member 2A are connected by inserting the connecting member 34 from the speed reduction member 2 side into the second hole 161 and threadedly fastening it. Thus, the speed reduction device 100A in which the motor 1A and the speed reduction member 2A are integrated is configured. Figure 9

[0092] The two third gears 30, 31 of the speed reduction member 2A are connected to the first rotary shaft 16a. That is, in the speed reduction device 100A, the wheel carrier is not used, and the third gears 30, 31 are directly connected to the combined rotary shaft, and the third gears 30, 31 function as input shafts that input driving force to the speed reduction member 2A. In addition, the output shaft 25 is supported by the bearing 37 mounted on the third gear 31.

[0093] In the speed reduction device 100A, the peripheral surface on the radially inner side of the bearing 39 opposes the protrusion 122 in the radial direction, and the motor 1A is connected to the speed reduction member 2A. The front end side of the first motor housing 12a in the axial direction is supported by the bearing 39 of the speed reduction member 2A, and the first motor housing 12a is supported by the two bearings 18, 19 on the motor 1 side, and thus the rigidity of the motor 1 can be improved. Thus, as with the speed reduction device 100, vibration of the combined rotary shaft can be prevented. Thus, the stability of the combined rotary shaft can be improved, and the stability of the entire speed reduction device can be improved.

[0094] [Second Embodiment]

[0095] Figure 10 The speed reduction device 200 illustrated is a second example of a speed reduction device, and has a motor 1 and a speed reduction member 2B. Hereinafter, structures different from the first embodiment will be described, and the same reference numerals will be assigned to the same structures as the speed reduction device 100, and detailed descriptions thereof will be omitted.

[0096] ​The reduction member 2B has two first gears 21a, 23a disposed on the side of the first motor housing 12 away from the motor 1, two second gears 22a, 24a engaged with the first gears 21a, 23a, two third gears 30, 31, an output shaft 25a, two rotating shafts 26a, 26b, two housings 36a, 36b, and a positioning ring 40 disposed between the two first gears 21a, 23a.

[0097] The radially outermost ends 210, 230 of the first gears 21a, 23a are located radially inward of the radially outermost end 123 of the first motor housing 12. Thus, the radial dimension of the reduction member 2B can be reduced.

[0098] The positioning ring 40 is disposed between the two first gears 21a, 23a, and thus can restrict both from moving in the axial direction relative to each other. Also, in the second embodiment 2, unlike the first embodiment, the second gear 22a is mounted on the rotating shaft 26a via a bearing 27, and the second gear 22b is mounted on the rotating shaft 26b via a bearing 27.

[0099] Also, in the second embodiment, the housing 36a is fixed to the first motor housing 12, and the end of the rotating shaft 26a is fixed to the housing 36a. On the other hand, the rotating shaft 26b is fixed to the output shaft 25a. The output shaft 25a is assembled to the housing 36b via a bearing 35, and is supported to the wheel carrier 32a via a bearing 37.

[0100] As shown in FIG. 1, the reduction member 2A shown in the present embodiment has two-stage planetary gear trains PGT1, PGT2, each of which includes three gears. Specifically, the planetary gear train PGT1 includes the first gear 21a, the second gear 22a, and the third gear 30. The planetary gear train PGT2 includes the first gear 23a, the second gear 24a, and the third gear 31. Figure 11 The second gear 22a in the planetary gear train PGT1 of the reduction member 2A can revolve around the third gear 30 with the central axis C as an axis in the radially inner periphery of the first gear 21a, and can rotate around the rotating shaft 26a. Also, the third gear 30 in the planetary gear train PGT1 can rotate or orbit with the central axis C as an axis together with the first rotating shaft 16. The second gear 24a in the planetary gear train PGT2 of the reduction member 2A can revolve around the third gear 31 with the central axis C as an axis in the radially inner periphery of the first gear 23a, and can rotate around the rotating shaft 26b. Also, the third gear 31 in the planetary gear train PGT2 can rotate or orbit with the central axis C as an axis together with the first rotating shaft 16.

[0101]

[0102] ​Here, the speed of the common gear is determined by the planetary gear system PGT1 on the input side. In Figure 10 In the example shown, let the number of the third gear 31 (sun gear), the second gear 22a (planetary gear), and the first gear 21a (ring gear) of the planetary gear system PGT1 be zl, z2, and z3, respectively, and let the number of the third gear 31 (sun gear), the second gear 24a (planetary gear), and the first gear 23a (ring gear) of the planetary gear system PGT2 be z4, z5, and z6, respectively. In this case, the reduction ratio is determined by the following equation. However, the reduction ratio is determined by the number of gears of the planetary gear systems PGT1 and PGT2.

[0103]

[0104] [Second Embodiment]

[0105] Figure 12 The reduction device 200A shown is a modification of the reduction device 200, and has a motor 1A and a reduction member 2C. The motor 1A and the reduction member 2C are integrated by a connecting member 34, and constitute the reduction device 200A. The motor 1A is of the same structure as the motor 1A of the above-described reduction device 100A. That is, in the motor 1A of the reduction device 200A, the rotating shaft is supported by two bearings 18 and 19, and thus the rigidity of the motor can be improved. Then, the connecting member 34 is inserted into the hole from the reduction member 2B side, and is threadedly fastened, and thus the combined rotating shaft and the reduction member 2B are connected. Thus, the reduction device 200A in which the motor 1A and the reduction member 2B are integrated is constituted.

[0106] The reduction member 2C has two third gears 30a and 31a, and the third gears 30a and 31a are connected to the first rotating shaft 16a. That is, in the reduction device 200A, the third gears 30a and 31a are directly connected to the combined rotating shaft without using a carrier, and the third gears 30a and 31a function as input shafts that input driving force to the reduction member 2C. In addition, the output shaft 25a is supported by a bearing 37 mounted on the third gear 31a.

[0107] [Third Embodiment]

[0108] Figure 13 The reduction device 300 shown is a third example of a reduction device, and has a motor 1B and a reduction member 2D. The motor 1B and the reduction member 2D are integrated by a connecting member 34, and constitute the reduction device 300. Hereinafter, the structure different from the reduction devices 100 and 200 will be described, and the same reference numerals are assigned to the same structures as those of the reduction devices 100 and 200, and detailed description thereof will be omitted.

[0109] The motor 1B includes a first motor housing 12 b and has the same other structures as the motor 1. The first motor housing 12 b includes an end portion 124 that protrudes toward one side away from the first rotor 14 in the axial direction.

[0110] The speed reduction member 2D includes a first gear 21b arranged on the side of the first motor housing 12b farther from the motor 1B, two second gears 22b and 24b meshing with the first gear 21b, two third gears 30b and 31b, a rotating shaft 26c, a housing 36b, a wheel carrier 41, and a bearing 42.

[0111] The first gear 21b extends axially longer than the first gear 21 of the first embodiment. This first gear 21b is shared with the second gears 22b and 24b. The first gear 21b is supported by a bearing 42 mounted on the housing 36b. Furthermore, the radially outermost end 210 of the first gear 21b is located radially inward of the radially outermost end 123 of the first motor housing 12b. This reduces the radial dimension of the deceleration component 2D.

[0112] In the third embodiment, the third gear 30b is fixed to the first motor housing 12b. Meanwhile, the third gear 31b is mounted on the housing 36b via a bearing 35 and supported on the wheel carrier 41 via a bearing 37. The third gear 31b in the third embodiment functions as an output shaft.

[0113] The two second gears 22b and 24b are mounted on the rotating shaft 26c via bearings 27. The two second gears 22b and 24b are rotatable about the rotating shaft 26c. The rotating shaft 26c is fixed to the wheel carrier 41 that inputs the driving force of the motor 1B to the speed reduction member 2C.

[0114] like Figure 14 As shown, the reduction gear unit 2D shown in this embodiment includes two-stage planetary gear trains PGT1 and PGT2. Each of the planetary gear trains PGT1 and PGT2 includes three gears. Specifically, the planetary gear train PGT1 includes a first gear 21b, a second gear 22b, a third gear 30b, and a carrier 41. The planetary gear train PGT2 includes a first gear 23b, a second gear 24b, a third gear 31b, and a carrier 41.

[0115] The second gear 22b in the planetary gear train PGT1 of the reduction gear 2D is capable of orbiting around the third gear 30b about the center axis C on the radially inner periphery of the first gear 21b and is capable of rotating about its own axis 26c. Furthermore, the third gear 30b in the planetary gear train PGT1 is capable of rotating or performing circular motion about the center axis C along with the first rotating shaft 16. The second gear 24b in the planetary gear train PGT2 of the reduction gear 2C is capable of orbiting around the third gear 31b about the center axis C on the radially inner periphery of the first gear 23b and is capable of rotating about its own axis 26c. Furthermore, the third gear 31b in the planetary gear train PGT2 is capable of rotating or performing circular motion about the center axis C along with the first rotating shaft 16.

[0116] Here, the speed of the carrier 41 is determined by the planetary gear train PGT1 on the input side. Figure 14 In this example, assume that the number of gears in the third gear 31b (sun gear), second gear 22b (planet gear), and first gear 21b (ring gear) of planetary gear train PGT1 is z1, z2, and z3, respectively. And assume that the number of gears in the third gear 31b (sun gear), second gear 24b (planet gear), and first gear 23b (ring gear) of planetary gear train PGT2 is z4, z5, and z6, respectively. The reduction ratio in this case is determined by the following equation. However, the reduction ratio is determined by the number of gears in the planetary gear trains PGT1 and PGT2.

[0117]

[0118] In the reduction gear 300, since the first gear 21b (ring gear) and the housing 36b of the reduction member 2D are a single structure, the device as a whole can be constructed with a relatively small number of components. Furthermore, the first gear 21b can be manufactured as a single component or as two components that are then connected to form a single component.

[0119] Furthermore, in the third embodiment, the wheel carrier 41 supports the axially intermediate portion of the rotating shaft 26c. The second gears 22b and 24b, located at the front and rear ends of the rotating shaft 26c, mesh with the first gear 21b and the third gears 30b and 31b, respectively. This provides high stability for the rotating shaft 26c. Consequently, the third embodiment eliminates the need for the first and second ring members 28 and 29 of the first embodiment. Furthermore, the overall device requires fewer components, further reducing the overall thickness of the structure.

[0120] [Modification of the Third Embodiment]

[0121] Figure 15The illustrated speed reducer 300A is a modification of the speed reducer 300, and has the motor 1A and the speed reduction member 2D. The motor 1A and the speed reduction member 2D are integrated by the connecting member 34, and constitute the speed reducer 300A. The motor 1A is of the same structure as the motor 1A of the speed reducer 100A described above, and the speed reduction member 2D is of the same structure as the speed reduction member 2D of the speed reducer 300 described above. In the motor 1A of the speed reducer 300A, since the rotation shaft is supported by the two bearings 18, 19, the rigidity of the motor can be improved. Then, the connecting member 34 is inserted into the hole from the speed reduction member 2D side, and is threadedly fastened, whereby the combined rotation shaft and speed reduction member 2D are connected. Thus, the speed reducer 300A in which the motor 1A and the speed reduction member 2D are integrated is constituted.

[0122] [Fourth Embodiment]

[0123] Figure 16 The illustrated speed reducer 400 is a fourth example of the speed reducer, and has the motor 1 and the speed reduction member 2E. The motor 1 and the speed reduction member 2E are integrated by the connecting member 34, and constitute the speed reducer 400. Hereinafter, the structure different from the first to third embodiments will be described, and for the same structure as the speed reducers 100, 200, 300, the same reference numerals are attached and detailed description thereof will be omitted.

[0124] The speed reduction member 2E has two first gears 21, 23, two second gears 22, 24, two third gears 30c, 31c, the output shaft 25, the rotation shaft 26, the ring member 28a disposed between the third gear 30c and the first motor housing 12, and the wheel carrier 43 disposed between the third gear 31c and the output shaft 25. The wheel carrier 43 functions as an input shaft that inputs the driving force of the motor 1 to the speed reduction member 2D.

[0125] The third gears 30c, 31c are separate bodies, but function as one gear by being connected to the motor 1 and the speed reduction member 2E. The third gears 30c, 31c are rotatable within the bearing 38 installed to the first motor housing 12.

[0126] The two second gears 22, 24 are each installed to the rotation shaft 26 by the bearing 27. The two second gears 22, 24 are each rotatable about the rotation shaft 26.

[0127] The first ring member 28a abuts against one end of the rotation shaft 26, and the wheel carrier 43 abuts against the other end of the rotation shaft 26. Thus, as in the first embodiment, in the speed reduction member 2E, the rotation shaft 26 is stably installed. The output shaft 25 is installed to the housing 36 by the bearing 35, and is supported to the wheel carrier 43 by the bearing 37.

[0128] As Figure 17As shown, the reduction mechanism 2E shown in the present embodiment has two-stage planetary gear trains PGT1, PGT2, each of which includes three gears. Specifically, the planetary gear train PGT1 includes a first gear 21, a second gear 22, a third gear 30c, and a carrier 43. The planetary gear train PGT2 includes a first gear 23, a second gear 24, a third gear 31c, and the carrier 43.

[0129] The second gear 22 in the planetary gear train PGT1 of the reduction mechanism 2E is capable of revolving around the third gear 30c with the central axis C as an axis at the radially inner periphery of the first gear 21 and is capable of rotating around the rotation axis 26. In addition, the third gear 30c in the planetary gear train PGT1 is capable of rotating or circularly moving with the first rotation axis 16 with the central axis C as an axis. The second gear 24 in the planetary gear train PGT2 of the reduction mechanism 2D is capable of revolving around the third gear 31c with the central axis C as an axis at the radially inner periphery of the first gear 23 and is capable of rotating around the rotation axis 26. In addition, the third gear 31c in the planetary gear train PGT2 is capable of rotating or circularly moving with the first rotation axis 16 with the central axis C as an axis.

[0130] Here, the speed of the carrier 43 is determined by the planetary gear train PGT1 on the input side. In the case of the planetary gear train PGT1, the number of the third gear 31c (sun gear), the second gear 22 (planetary gear), and the first gear 21 (ring gear) is z1, z2, and z3, respectively. In the case of the planetary gear train PGT2, the number of the third gear 31c (sun gear), the second gear 24 (planetary gear), and the first gear 23 (ring gear) is z4, z5, and z6, respectively. The reduction ratio in this case is determined by the following formula. Figure 16

[0131] In the reduction device 400 of the fourth embodiment, since the carrier 43 is directly fixed to the rotation axis 26, the stability of the rotation axis 26 is high. Therefore, in the fourth embodiment, it is not necessary to provide the second ring member 29 in the first embodiment. Moreover, as a whole of the device, a small number of components is sufficient, and it is possible to further reduce the thickness of the entire configuration.

[0132]

[0133]

Fourth Embodiment Variation

[0134] Figure 18 ​The illustrated speed reducer 400A is a modification of the speed reducer 400, and has a motor 1C and a speed reduction member 2E. The motor 1C and the speed reduction member 2E are integrated by a connecting member 34, and constitute the speed reducer 400A. The motor 1C has the same first motor housing 12 as the motor 1 described above and the same second motor housing 13a as the motor 1A described above. The speed reduction member 2E has the same structure as the speed reduction member 2E of the speed reducer 400 described above. In the motor 1C of the speed reducer 400A, the combined rotating shaft is supported by two bearings 18, 19, and by two bearings 38, 39 on the speed reduction member 2E side, so the rigidity of the motor can be further improved. Also, the combined rotating shaft and the speed reduction member 2E are connected by inserting the connecting member 34 from the speed reduction member 2E side into a second hole (not shown) and threadedly fastening it. Thus, the speed reducer 400A is constituted in which the motor 1C and the speed reduction member 2E are integrated.

[0135] In addition, the present application is not limited to the first to fourth embodiments, and the motor and the speed reduction member can have other configurations.

[0136] The present application has been described above in connection with specific embodiments, and it will be readily apparent to those skilled in the art that many modifications and variations of the present application can be made in light of the above teachings without departing from the scope and spirit of the application. Accordingly, the application is not to be restricted based on the specific embodiments that are described above.

[0137] Industrial Applicability

[0138] The speed reducer of the present application can be used in all technical fields in which a speed reducer is used. In particular, it can be widely used in speed reducers in which a motor and a speed reducer are integrated and miniaturization is required.

[0139] Explanation of Reference Numerals

[0140] 1: motor; 2: speed reduction member; 11: stator; 12: first motor housing; 120: first end portion; 121: second end portion; 13: second motor housing; 14: first rotor; 15: second rotor; 16: first rotary shaft; 160: hole; 17: second rotary shaft; 170: through-hole; 171: recess; 18: bearing; 19: bearing; 21: first gear; 22: second gear; 23: first gear; 24: second gear; 25: output shaft; 26: rotary shaft; 27: bearing; 28: first ring member; 29: second ring member; 30, 31: third gear; 32: carrier; 33, 34: connecting member; 35: bearing; 36: housing; 37: bearing; 38: first bearing; 39: second bearing; 40: positioning ring; 41: carrier; 42: bearing; 43: carrier; 50: connecting member; 100: speed reduction device; 200: speed reduction device; 300: speed reduction device; 400: speed reduction device.

Claims

1. A speed reduction device, comprising: a motor having first and second rotary shafts, the first and second rotary shafts rotating about a center axis, a first rotor disposed radially outward of the first rotary shaft, a second rotor disposed radially outward of the second rotary shaft, a stator disposed between the first and second rotors, a first motor case disposed axially away from the first rotor, and a second motor case disposed axially away from the second rotor; and a speed reduction member having a first gear disposed axially away from the first motor case and rotating about the center axis, a second gear engaged with the first gear, a third gear engaged with the second gear, the second gear being mounted to a rotary shaft so as to be able to rotate about the rotary shaft, the third gear driving rotation of the second gear, the second gear driving an output shaft, and a carrier disposed between the output shaft and the first rotary shaft.

2. The speed reduction device according to claim 1, wherein the first gear comprises two gears disposed axially adjacent to each other.

3. The speed reduction device according to claim 1 or 2, wherein the speed reduction member comprises: a first ring member disposed between the third gear and the first motor case; and a second ring member disposed between the third gear and the output shaft.

4. The speed reduction device according to claim 1 or 2, wherein the second rotary shaft has a through hole extending through in the axial direction, and a connecting member for connecting the first and second rotary shafts is disposed in the through hole.

5. The speed reduction device according to claim 1, wherein the first motor case has a first end portion disposed axially away from the first rotor, the bearing of the speed reduction member comprises a first bearing, and the first bearing is disposed radially inward of the first gear. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The first bearing is located radially inside the third gear, and a radially inner circumferential surface of the first bearing is radially opposed to the first end portion.

6. The speed reduction device according to claim 5, wherein The first motor housing further has a second end portion connected to the first end portion on an axially other side of the first rotor, The bearing of the speed reduction member further includes a second bearing, The second bearing is located between the first ring member and the first motor housing, and a radially inner circumferential surface of the second bearing is radially opposed to the second end portion.

7. The speed reduction device according to claim 1 or 2, wherein The motor has a bearing on an axially other side of the second rotary shaft away from the first rotary shaft, The second motor housing has a protrusion protruding toward an axially one side, An end portion of the second rotary shaft on an axially other side has a recess, The bearing is arranged between an inner circumferential surface of the recess and an outer circumferential surface of the protrusion.

8. The speed reduction device according to claim 1, wherein The number of the second gears is at least two or more, The two or more second gears are arranged in a circumferential direction around the center axis.

9. The speed reduction device according to claim 1 or 2, wherein The first gear is a ring gear, The second gear is a planetary gear, The third gear is a sun gear.

10. The speed reduction device according to claim 1, wherein The motor is an axial flux motor.

11. The speed reduction device according to claim 1, wherein The speed reduction member further has a bearing arranged radially outside the output shaft.

12. The speed reduction device according to claim 2, wherein A positioning portion is provided between two axially adjacent second gears.

13. The speed reduction device according to claim 1, wherein A radially outermost end of the first gear is located radially inside a radially outermost end of the first motor housing.

14. The speed reduction device according to claim 1, wherein One end of the wheel carrier is connected to the first rotary shaft, and the other end is connected to the third gear.

15. The speed reduction device according to claim 2, wherein One end of the wheel carrier is connected to the first rotary shaft, and the other end is connected to the rotary shaft.

16. An electric device, wherein The electric device has the speed reduction device according to any one of claims 1 to 15.

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