CN116194687A - Speed reduction device and electrical equipment - Google Patents

Abstract

The thickness of the whole structure can be further reduced while realizing a high reduction ratio. The reduction gear includes a motor and a reduction member disposed in an axial direction, the reduction member includes a first gear disposed on one side of a 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 axial side of the first motor housing, the reduction member includes at least one bearing disposed on a radially inner side of the first gear, and the first gear includes at least one of the second gear and the third gear, and the second gear and the third gear include two gears disposed adjacent to each other in the axial direction, respectively, so that it is possible to further reduce a thickness of the entire structure in the axial direction and the radial direction while realizing a high reduction ratio.

Description

Speed reduction device and electrical equipment

Technical Field

The present invention relates to a reduction gear and an electrical apparatus. The present application claims priority based on 24 th 9 th 2020 in japanese patent application No. 2020-159870, the contents of which are incorporated herein by reference.

Background

Conventionally, there is a technique of combining a motor and a reduction gear. A typical combination of a motor and a decelerator is a configuration in which the decelerator is directly connected to the motor. The combined motor and decelerator actuator is the main component of the robotic application. In order to output a large torque, the decelerator is required to have a high reduction ratio in order to convert a high-speed low-torque output of the motor into a low-speed high-torque output.

In general, a reduction gear having a high reduction ratio uses a multistage planetary gear device that is long in the axial direction, and thus the device is large-sized. For example, patent documents 1 and 2 below propose a reduction gear having a multistage planetary gear device. According to the device, a high reduction ratio can be obtained.

Further, for example, patent document 3 below proposes a reduction gear having a double-stage planetary gear device, and a greatly improved reduction ratio can be obtained by using the double-stage gear device.

For example, patent document 4 below proposes a configuration in which a motor has a space in the center and a speed reducer is mounted in the space. In this technique, the entire device is designed to be axially thinner.

Prior art literature

Patent literature

Patent document 1: U.S. Pat. No. 8829750 Specification

Patent document 2: chinese patent publication No. 103545981

Patent document 3: U.S. publication No. 20110009232

Patent document 4: chinese patent publication No. 101258664

Disclosure of Invention

Problems to be solved by the invention

However, in the technology in which only the speed reducer having the multistage planetary gear device of the above patent documents 1 and 2 or the speed reducer having the double stage planetary gear device of the above patent document 3 is simply combined with the motor, although a high reduction ratio can be obtained, there is a problem in that the size of the entire device in the axial direction is increased. On the other hand, in patent document 4, in order to install a speed reducer in a space of a motor, an outer diameter of the motor is increased.

The present invention has been made in view of the above circumstances, and an object thereof is to enable realization of a high reduction ratio (high output torque) and further reduction in thickness of the entire structure.

Means for solving the problems

The speed reduction device according to one embodiment of the present invention includes: a motor including a first rotating shaft and a second rotating shaft that rotate about a central axis, a first rotor disposed radially outward of the first rotating shaft, a second rotor disposed radially outward of the second rotating shaft, a stator disposed between the first rotor and the second rotor, and a first motor housing disposed on one side of the first rotor in an axial direction away from the stator, and a second motor housing disposed on the other side of the second rotor in an axial direction away from the stator; and a speed reduction member having a first gear disposed on one side in a radial direction away from the first motor housing and rotating about the central axis, a second gear meshing with the first gear, a third gear meshing with the second gear, the second gear being rotatably attached to the rotation shaft, the third gear driving rotation of the second gear, the second gear driving the output shaft, and a carrier disposed between the output shaft and the first rotation shaft, the motor having at least one bearing disposed on an outer side in the radial direction of the first rotation shaft, the bearing being disposed between the first rotor and the first motor housing, the speed reduction member having at least one bearing disposed on an inner side in the radial direction of the first gear, the first gear being at least one, the second gear and the third gear each including two gears disposed adjacent to each other in the axial direction.

The first gear may include two gears disposed adjacent to each other in the axial direction.

The speed reducing member has a first ring member disposed between the third gear and the first motor housing, and a second ring member disposed between the third gear and the output shaft, the first ring member being in contact with one end of the rotating shaft, and the second ring member being in contact with the other end of the rotating shaft.

The second rotation shaft has a through hole penetrating in the axial direction, and a connecting member for connecting the first rotation shaft and the second rotation shaft is provided in the through hole.

The first motor case may have a first end portion on an axial side away from the first rotor, the bearing of the speed reduction member may include a first bearing, the first bearing may be located radially inward of the third gear, and a circumferential surface of the radially inward of the first bearing may be radially opposed to the first end portion.

The first motor case may further include a second end portion connected to the first end portion on the other side in the axial direction of the first rotor, and the bearing of the speed reducing member may further include a second bearing located between the first ring member and the first motor case, and a circumferential surface of the second bearing on the radially inner side may be radially opposed to the second protruding portion.

According to another embodiment of the present invention, the motor has a bearing on the other side of the second rotation shaft in the axial direction away from the first rotation shaft, the second motor housing has a convex portion protruding toward one side in the axial direction, the second rotation shaft has a concave portion at the other end in the axial direction, and the bearing is disposed between an inner peripheral surface of the concave portion and an outer peripheral surface of the convex portion.

Preferably, the number of the second gears is at least two, and the two or more second gears are arranged in a circumferential direction around the central axis.

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

Preferably, the motor is an axial flux motor.

Preferably, the speed reducing member further includes a bearing disposed radially outward of the output shaft.

According to another embodiment of the present invention, a positioning portion may be provided between two of the second gears disposed adjacent to each other in the axial direction.

According to another embodiment of the present invention, the radially outermost end of the first gear may be located radially inward of the radially outermost end of the first motor case.

According to another embodiment of the present invention, the wheel carrier may have one end connected to the first rotation shaft and the other end connected to the third gear.

According to another embodiment of the present invention, the wheel frame may have one end connected to the first rotation shaft and the other end connected to the rotation shaft.

An electric device having a reduction gear unit according to an embodiment of the present invention can be provided.

Effects of the invention

In one embodiment of the present invention, the reduction gear includes a motor and a reduction member disposed in an axial direction, the reduction member includes a first gear disposed in the first motor housing and apart from one of the motors, 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 disposed on one axial side of the first motor housing, the reduction member includes at least one bearing disposed radially inward of the first gear, and the first gear includes at least one of the second gear and the third gear, and the second gear and the third gear include two gears disposed adjacent to each other in the axial direction.

Drawings

Fig. 1 is a perspective view showing a state in which a reduction member is separated from a motor, in a first embodiment of a reduction gear.

Fig. 2 is a cross-sectional view showing a structure in which the reduction member of the first embodiment is separated from the motor.

Fig. 3 is a sectional view partially showing the structure of the first rotation shaft and the second rotation shaft.

Fig. 4 is a cross-sectional view showing the structure of the first embodiment.

Fig. 5 is a diagram showing a planetary gear train of the reduction member of the first embodiment.

Fig. 6 is a perspective view showing a structure of a part of the speed reducing member of the first embodiment.

Fig. 7A is a part of the speed reducing member of the first embodiment, and is a plan view showing the structure of the first-stage planetary gear train.

Fig. 7B is a part of the speed reducing member of the first embodiment, and is a plan view showing the structure of the second-stage planetary gear train.

Fig. 8 is a perspective view showing a state in which a reduction member is separated from a motor, in a modification of the first embodiment of the reduction gear.

Fig. 9 is a cross-sectional view showing a structure of a modification of the first embodiment.

Fig. 10 is a cross-sectional view showing the structure of the second embodiment of the reduction gear.

Fig. 11 is a diagram showing a planetary gear train of the reduction member of the second embodiment.

Fig. 12 is a cross-sectional view showing a configuration of a modification of the second embodiment of the reduction gear.

Fig. 13 is a cross-sectional view showing the structure of a third embodiment of the reduction gear.

Fig. 14 is a diagram showing a planetary gear train of the reduction member of the third embodiment.

Fig. 15 is a cross-sectional view showing a structure of a modification of the third embodiment of the reduction gear.

Fig. 16 is a cross-sectional view showing the structure of a fourth embodiment of the reduction gear.

Fig. 17 is a diagram showing a planetary gear train of the reduction member of the fourth embodiment.

Fig. 18 is a cross-sectional view showing a configuration of a modification of the fourth embodiment of the reduction gear.

Detailed Description

An embodiment of a reduction gear unit will be described as an example of the present invention with reference to fig. 1 to 18. Hereinafter, for convenience of explanation, a radial direction centering on central axes of the first and second rotary shafts of the motor is referred to as a "radial direction", a direction around the central axis is referred to as a "circumferential direction", and an extending direction of the central axis and a direction parallel thereto are referred to as an "axial direction". In the axial direction, the direction in which the motor is directed toward the speed reduction member is referred to as "forward", and the direction opposite to the "forward" is referred to as "rearward".

[ first embodiment ]

As shown in fig. 1, a reduction gear 100 according to 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 is shown separated from the reduction member 2. Then, the motor 1 and the reduction member 2 are integrated in the axial direction by the bolts 34 to constitute the reduction gear 100.

As shown in fig. 2, the motor 1 includes a first rotary shaft 16 and a second rotary shaft 17 that rotate about a central axis C indicated by a chain line, a first rotor 14 disposed radially outward of the first rotary shaft 16, a second rotor 15 disposed radially outward of the second rotary shaft 17, a stator 11 disposed between the first rotor 14 and the second rotor 15, a first motor housing 12 disposed on one side of the first rotor 14 in an axial direction away from the stator 11, a second motor housing 13 disposed on the other side of the second rotor 15 in an axial direction away from the stator 11, and one bearing 18 disposed radially outward of the first rotary shaft 16. The motor 1 has two rotors, sometimes referred to as a double rotor motor in this specification.

In the example of fig. 2, the stator 11 is defined, the first motor housing 12 is located on the front side of the stator 11, and the second motor housing 13 is located on the rear side of the stator 11. The first rotor 14 is located in front of the stator 11 and between the stator 11 and the first motor housing 12. In addition, the second rotor 15 is located behind the stator 11, and is located between the stator 11 and the second motor housing 14. The bearing 18 is axially located between the first rotor 14 and the first motor housing 12. The first rotor 14 and the second rotor 15 in the present embodiment are, for example, disk-shaped disk rotors.

In the present embodiment, the motor 1 and the reduction member 2 are disposed in the axial direction, and the reduction member 2 is provided on the front side of the motor 1, for example, the reduction member 2 is located on the front side of the first motor housing 12.

The first motor housing 12 has a first end 120 on one side in the axial direction away from the first rotor 14 and a second end 121 connected to the first end 120 on the other side in the axial direction near the first rotor 14. The first rotation shaft 16 is located radially inward of the first end 120 and the second end 121.

In the present embodiment, the bearing 18 is located between the second end 121 and the first rotation shaft 16. The first rotary shaft 16 and the second rotary shaft 17 in the present embodiment are rotatably supported by one bearing 18 in the first motor housing 12. This allows a space to be formed in the front side of the first motor case 12, for example, as compared with a case where a plurality of bearings are provided in the front side of the stator 11.

As shown in fig. 3, the second rotary shaft 17 has a through hole 170 penetrating in the axial direction. The through hole 170 is located axially rearward of the second rotary shaft 17. The through hole 170 is provided with a connecting member 50 for connecting the first rotary shaft 16 and the second rotary shaft 17. The connection member 50 is, for example, a bolt. The connection member 50 is not limited to a bolt, and may be a member other than a bolt.

As shown in fig. 2 and 3, the first rotation 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 rotation shaft 16 in the axial direction, toward the second rotation shaft 17 side. The second hole 161 is located on the front side of the first rotation shaft 16 in the axial direction, toward the reduction member 2 side. The first and second holes 160 and 161 are each internally threaded holes, for example, having internal threads.

When the first rotation shaft 16 and the second rotation shaft 17 are connected, the connection member 50 is inserted from the through hole 170 and screwed into the first hole 160, whereby the first rotation shaft 16 and the second rotation shaft 17 are connected, and a combined rotation shaft in which both rotation shafts are combined can be formed. The first rotation shaft 16 and the second rotation shaft 17 may have a hollow structure. This reduces the weight of the first rotation shaft 16 and the second rotation shaft 17. The combined rotary shaft as used herein refers to a rotary shaft in which two rotary shafts are combined so as to be connected to each other in the axial direction.

A connection member 34 for connecting the above-described combined rotary shaft and reduction member 2 is provided in the second hole 161. The connection member 34 is, for example, a bolt. The connection member 34 is not limited to a bolt, and may be a member other than a bolt. The coupling member 34 is inserted into the second hole 161 from the reduction member 2 side and screw-fastened, thereby coupling the combined rotary shaft and the reduction member 2. Thus, the reduction gear 100 is formed by integrating the motor 1 and the reduction member 2 shown in fig. 3.

Next, the structure of the reduction member 2 will be described in detail. As shown in fig. 4, the speed reduction member 2 includes two first gears 21 and 23 disposed on one side of the first motor housing 12 in the axial direction of the motor 1, two second gears 22 and 24 meshing with the first gears 21 and 23, two third gears 30 and 31, and an output shaft 25 driven by the second gears (in the present embodiment, the second gear 24) while the third gears 30 and 31 drive the rotation of the second gears 22 and 24, a rotation shaft 26, and a carrier 32 disposed between the output shaft 25 and the first rotation shaft 16.

As shown in fig. 5, 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.

The planetary gear trains PGT1 and PGT2 are located on the axially outer side, i.e., the front side, of the first motor housing 12 shown in fig. 4. In addition, the planetary gear trains PGT1 and PGT2 are each located radially outside the bearing 18.

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 disposed adjacent to each other in the axial direction. The two second gears 22, 24 are each mounted on a rotary shaft 26 by means of bearings 27. The two third gears 30 and 31 are disposed adjacent to each other in the axial direction. The two third gears 30 and 31 are mounted on the carrier 32 by bolts 33, and are formed as a common gear integrally. The reduction member 2 according to the present embodiment is configured as a double-stage planetary gear device, and therefore a higher reduction ratio can be obtained than that of a 1-stage planetary gear device.

The reduction member 2 has a first ring member 28 disposed between the third gear 30 and the first motor housing 12, and a second ring member 29 disposed between the third gear 31 and the output shaft 25. The first ring member 28 is connected to one end of the rotary shaft 26 of the third gear, and the second ring member 29 is connected to the other end of the rotary shaft 26. That is, the rotation shaft 26 is fixed by the first ring member 28 and the second ring member 29. The rotation shaft 26 is integrally formed with a first ring member 28 and a second ring member 29. Thereby, the rotation shaft 26 is stably mounted in the reduction member 2. The rotation shaft 26 is a rotation shaft shared by the two-stage gear structure of the present invention in a state of being integrated with the first ring member 28 and the second ring member 29.

The reduction member 2 has at least one bearing disposed radially inward of the first gear 21. In the present embodiment, the bearings of the reduction member 2 include 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. When the motor 1 is connected to the reduction member 2, the radially inner circumferential surface of the first bearing 38 is aligned so as to be radially opposed to the first end 120, and the radially inner circumferential surface of the second bearing 39 is aligned so as to be radially opposed to the second protruding portion 121.

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

The radially outermost end 320 of the carrier 32 is disposed radially inward of the radially innermost end 250 of the output shaft 25. Thus, the carrier 32 does not interfere with the rotation of the output shaft 25, and the axial thickness of the reduction member 2 can be further reduced. In this way, the axial thickness of the reduction gear 100 can be further reduced.

The reduction gear 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 in a bearing 35. The bearing 35 mounts the output shaft 25 to the housing 36 of the reduction member 2. The bearing 37 is supported by the wheel carrier 32.

In the present embodiment, since one bearing 18 is located on the front side of the stator 11 in the axial direction as shown in fig. 4, a large space surrounding the bearing 18 can be formed on the front side of the first motor case 12 of the motor 1, and the 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. Thereby, the motor 1 and the reduction member 2 are constituted to be small in the axial direction and the radial direction.

In the present embodiment, the first bearing 38 and the second bearing 39 of the speed reducing member 2 support the axial tip side of the first motor housing 12. That is, since the radially inner peripheral surface of the first bearing 38 and the first end 120 shown in fig. 2 are radially opposed to each other, and the radially inner peripheral surface of the second bearing 39 and the second protrusion 121 are radially opposed to each other, the motor 1 is connected to the reduction member 2, and the first motor housing 12 is supported by the bearing 18 on the motor 1 side, the first bearing 38 on the reduction member 2 side, and the second bearing 39, the rigidity of the motor 1 can be improved. Therefore, vibration of the combined rotary shaft can be prevented. This can improve the stability of the combined rotating shaft and the stability of the entire reduction gear.

The motor 1 shown in the present embodiment is preferably an Axial flux motor (Axial flux motor). Since the motor 1 is axially short, the overall configuration of the reduction gear 100 can be made more compact.

In the present embodiment, as shown in fig. 6, the first gears 21 and 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.

The diameters of the two second gears of the present invention, namely the second gear 22 and the second gear 24, are different. For example, the diameter of the second gear 22 is greater than the diameter of the second gear 24. The diameter of the second gear 22 may be the same as that of the second gear 24, for example.

As shown in fig. 7A, the second gear 22 in the planetary gear train PGT1 is capable of revolving around the third gear 30 around the central axis C on the radially inner periphery of the first gear 21, and is capable of rotating around the rotation shaft 26. In addition, the third gear 30 in the planetary gear train PGT1 can perform rotation or circular movement with the first rotation shaft 16 about the central axis C.

As shown in fig. 7B, the second gear 24 in the planetary gear train PGT2 is capable of revolving around the third gear 31 around the central axis C on the radially inner periphery of the first gear 23, and is capable of rotating around the rotation shaft 26. In addition, the third gear 31 in the planetary gear train PGT2 can rotate or circularly move with the first rotation shaft 16 about the central axis C. The first gears 21, 23, the second gears 22, 24, and the third gears 30, 31 are not limited to the above-described configuration.

The second gears 22, 24 may also be fixed to the rotary shaft 26. The front end of the rotation shaft 26 may be attached to the wheel frame 32. Thereby, the second gears 22, 24 can rotate around the rotation shaft 26 in the carrier 32 by journal bearings or roller bearings.

The number of the second gears 22, 24 may be two or more, and the two or more second gears 22, 24 may be arranged in a circumferential direction around the central axis C. The number of the second gears 22, 24 may be determined according to the reduction ratio that the reduction member 2 needs to obtain. In one embodiment, the number of second gears 22, 24 may each be, for example, 4 to 10. In the present embodiment, the number of the second gears 22, 24 is 6.

Here, the speed of the carrier 32 is determined by the planetary gear train PGT1 on the input side. In the example of fig. 4, the numbers of the third gear 30 (sun gear), the second gear 22 (planet gear), and the first gear 21 (ring gear) in the planetary gear train PGT1 are z1, 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) in the planetary gear train 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 number of gears of the planetary gear trains PGT1, PGT 2.

As described above, the reduction gear 100 according to the first embodiment includes the dual-rotor motor (motor 1) and the reduction member 2, the dual-rotor motor and the reduction member 2 are disposed in the axial direction, the reduction member 2 includes the first gear disposed 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 located on the axial outer side of the first motor case, and the reduction member 2 further includes at least one bearing disposed on the radial inner side of the first gear, and therefore, the dual-rotor motor and the reduction gear can be made compact in the axial direction and the radial direction, and a reduction gear having a small size and a strong driving capability can be obtained.

Further, since the first gear, the second gear, and the third gear each include two gears disposed adjacent to each other, a high reduction ratio can be realized, and the thickness of the entire structure can be further reduced as compared with a case of a multistage structure in which three or more gears are overlapped.

In addition, in the reduction gear 100, the third gears 30 and 31 are assembled after being manufactured separately, or manufactured as one member including the carrier 32. In the reduction gear 100, the first gear 23 and the output shaft 25 are manufactured separately and then assembled, or manufactured as one piece.

[ modification of the first embodiment ]

The reduction gear 100A shown in fig. 8 is a modification of the reduction gear 100, and includes a motor 1A and a reduction member 2A. The motor 1A and the reduction member 2A are integrated by the connecting member 34 to constitute a reduction gear 100A. Hereinafter, a structure different from that of the reduction gear 100 will be described, and the same reference numerals will be given to the same structures as those of the reduction gear 100, and detailed description thereof will be omitted.

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 side of the second rotary shaft 17a in the axial direction from the first rotary shaft 16 a. The first motor housing 12a has an end 122 protruding toward one side in the axial direction away from the first rotor 14. The second motor housing 13a has a convex portion 130 protruding toward one axial side, and the second rotary shaft 17a has a concave portion 171 at the other axial side end. The bearing 19 is disposed between the inner peripheral surface of the concave portion 171 and the end surface of the convex portion 130.

In the motor 1A, the rotation shaft is supported by two bearings 18, 19. That is, the second rotary shaft 17a on the rear side (rear side) is supported by the bearing 19, and the first rotary shaft 16a on the front side (front side) is supported by the bearing 18, so that the rigidity of the motor can be improved. Further, the combined rotary shaft and the reduction member 2A are connected by inserting the connecting member 34 into the second hole 161 from the reduction member 2 side and screw-fastening. Thus, the reduction gear 100A is configured by integrating the motor 1A and the reduction member 2A shown in fig. 9.

The two third gears 30, 31 of the reduction member 2A are connected to the first rotation shaft 16 a. That is, in the reduction gear 100A, the third gears 30 and 31 are directly connected to the combined rotation shaft without using a carrier, and the third gears 30 and 31 function as input shafts for inputting driving force to the reduction member 2A. In addition, the output shaft 25 is supported by a bearing 37 mounted on the third gear 31.

In the reduction gear 100A, the radially inner peripheral surface of the bearing 39 is radially opposed to the convex portion 122, and the motor 1A is connected to the reduction member 2A. The front end side in the axial direction of the first motor housing 12A 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, so that the rigidity of the motor 1 can be improved. Therefore, vibration of the combined rotary shaft can be prevented as in the reduction gear 100. This can improve the stability of the combined rotating shaft and the stability of the entire reduction gear.

[ second embodiment ]

The reduction gear 200 shown in fig. 10 is a second example of a reduction gear, and includes a motor 1 and a reduction member 2B. The following description will be given of a configuration different from that of the first embodiment, and the same reference numerals are given to the same configuration as the reduction gear 100, and detailed description thereof will be omitted.

The speed reducing member 2B has two first gears 21a and 23a arranged on one of the first motor housing 12 away from the motor 1, two second gears 22a and 24a meshing with the first gears 21a and 23a, two third gears 30 and 31, an output shaft 25a, two rotary shafts 26a and 26B, two housings 36a and 36B, and a positioning ring 40 arranged between the two first gears 21a and 23 a.

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. Thereby, the radial dimension of the reduction member 2B can be reduced.

The positioning ring 40 is disposed between the two first gears 21a and 23a, and therefore can restrict movement of both in the axial direction. In addition, in the second embodiment 2, unlike the first embodiment, the second gear 22a is attached to the rotation shaft 26a through a bearing 27, and the second gear 22b is attached to the rotation shaft 26b through a bearing 27.

In the second embodiment, the housing 36a is fixed to the first motor housing 12, and the end of the rotation shaft 26a is fixed to the housing 36 a. On the other hand, the rotation 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 by the carrier 32a via a bearing 37.

As shown in fig. 11, the reduction member 2A of the present embodiment has two-stage planetary gear trains PGT1, PGT2, and the planetary gear trains PGT1, PGT2 each include three gears. Specifically, the planetary gear train PGT1 includes a first gear 21a, a second gear 22a, and a third gear 30. The planetary gear train PGT2 includes a first gear 23a, a second gear 24a, and a third gear 31.

The second gear 22A in the planetary gear train PGT1 of the reduction member 2A is capable of revolving around the third gear 30 around the central axis C on the radially inner periphery of the first gear 21a, and is capable of rotating around the rotation shaft 26 a. In addition, the third gear 30 in the planetary gear train PGT1 can perform rotation or circular movement with the first rotation shaft 16 about the central axis C. The second gear 24a in the planetary gear train PGT2 of the speed reducing member 2A is capable of revolving around the third gear 31 around the central axis C on the radially inner periphery of the first gear 23a, and is capable of rotating around the rotation shaft 26 b. In addition, the third gear 31 in the planetary gear train PGT2 can rotate or circularly move with the first rotation shaft 16 about the central axis C.

Here, the speed of the common gear is determined by the planetary gear train PGT1 on the input side. In the example of fig. 10, the numbers of the third gears 31 (sun gears), the second gears 22a (planet gears), and the first gears 21a (ring gears) of the planetary gear train PGT1 are z1, z2, and z3, respectively, and the numbers of the third gears 31 (sun gears), the second gears 24a (planet gears), and the first gears 23a (ring gears) of the planetary gear train 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 number of gears of the planetary gear trains PGT1, PGT 2.

Modification of the second embodiment

The reduction gear 200A shown in fig. 12 is a modification of the reduction gear 200, and includes a motor 1A and a reduction member 2C. The motor 1A and the reduction member 2C are integrated by the connecting member 34 to constitute a reduction gear 200A. The motor 1A has the same structure as the motor 1A of the reduction gear 100A. That is, in the motor 1A of the reduction gear 200A, the rotation shaft is supported by the two bearings 18 and 19, so that 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 screw fastening is performed, thereby connecting the combined rotary shaft and the reduction member 2B. Thus, the reduction gear 200A is formed by integrating the motor 1A and the reduction member 2B.

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

[ third embodiment ]

The reduction gear 300 shown in fig. 13 is a third example of a reduction gear, and includes a motor 1B and a reduction member 2D. The motor 1B and the reduction member 2D are integrated by the connecting member 34 to form the reduction gear 300. Hereinafter, the configuration different from those of the reduction gear units 100 and 200 will be described, and the same reference numerals will be given to the same configurations as those of the reduction gear units 100 and 200, and detailed description thereof will be omitted.

The motor 1B has a first motor housing 12B, and the other structures are the same as the motor 1. The first motor housing 12b has an end 124 protruding toward one side in the axial direction away from the first rotor 14.

The speed reducing member 2D has one first gear 21B disposed on one side of the first motor housing 12B away from the motor 1B, two second gears 22B, 24B meshing with the first gear 21B, two third gears 30B, 31B, one rotation shaft 26c, a housing 36B, a carrier 41, and a bearing 42.

The first gear 21b extends longer in the axial direction than the first gear 21 of the first embodiment. The first gear 21b is a gear commonly used with respect to the second gears 22b and 24 b. The first gear 21b is supported by a bearing 42 mounted on the housing 36 b. Further, 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 12 b. Thereby, the radial dimension of the reduction member 2D can be reduced.

In the third embodiment, the third gear 30b is fixed to the first motor housing 12 b. On the other hand, the third gear 31b is mounted on the housing 36b through a bearing 35, and is supported on the wheel carrier 41 through a bearing 37. The third gear 31b of the third embodiment functions as an output shaft.

The two second gears 22b, 24b are respectively mounted on the rotation shaft 26c through bearings 27. The two second gears 22b, 24b are rotatable about the rotation shaft 26 c. The rotation shaft 26C is fixed to a wheel carrier 41 that inputs the driving force of the motor 1B to the speed reduction member 2C.

As shown in fig. 14, the speed reducing member 2D of the present embodiment has two-stage planetary gear trains PGT1, PGT2, and the planetary gear trains PGT1, PGT2 each include 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.

The second gear 22b in the planetary gear train PGT1 of the reduction member 2D is capable of revolving around the third gear 30b around the central axis C on the radially inner periphery of the first gear 21b, and is capable of rotating around the rotation shaft 26C. In addition, the third gear 30b in the planetary gear train PGT1 can rotate or circularly move with the first rotation shaft 16 about the central axis C. The second gear 24b in the planetary gear train PGT2 of the speed reducing member 2C is capable of revolving around the third gear 31b around the central axis C in the radially inner periphery of the first gear 23b, and is capable of rotating around the rotation shaft 26C. In addition, the third gear 31b in the planetary gear train PGT2 can rotate or circularly move with the first rotation shaft 16 about the central axis C.

Here, the speed of the carrier 41 is determined by the planetary gear train PGT1 on the input side. In the example of fig. 14, the numbers of the third gears 31b (sun gears), the second gears 22b (planet gears), and the first gears 21b (ring gears) of the planetary gear train PGT1 are z1, z2, and z3, respectively, and the numbers of the third gears 31b (sun gears), the second gears 24b (planet gears), and the first gears 23b (ring gears) of the planetary gear train 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 number of gears of the planetary gear trains PGT1, PGT 2.

In the reduction gear 300, the first gear 21b (ring gear) and the housing 36b of the reduction member 2D are formed as a single unit, so that a smaller number of parts is sufficient as a whole. The first gear 21b may be manufactured as one member or may be manufactured as two members and then connected as one member.

In the third embodiment, the wheel carrier 41 supports the intermediate portion of the rotation shaft 26c in the axial direction, and the second gears 22b and 24b provided at the front end and the rear end of the rotation shaft 26c are engaged with the first gear 21b and the third gears 30b and 31b, respectively, so that the stability of the rotation shaft 26c is high. Therefore, in the third embodiment, the first ring member 28 and the second ring member 29 in the first embodiment need not be provided. Moreover, as the whole apparatus, a smaller number of parts is sufficient, and the thickness of the whole construction can be further reduced.

Modification of the third embodiment

The reduction gear 300A shown in fig. 15 is a modification of the reduction gear 300, and includes a motor 1A and a reduction member 2D. The motor 1A and the reduction member 2D are integrated by the connecting member 34 to constitute a reduction gear 300A. The motor 1A has the same structure as the motor 1A of the reduction gear 100A, and the reduction member 2D has the same structure as the reduction member 2D of the reduction gear 300. In the motor 1A of the reduction gear 300A, the rotation shaft is supported by the two bearings 18 and 19, so that the rigidity of the motor can be improved. Then, the connecting member 34 is inserted into the hole from the reduction member 2D side, and screw fastening is performed, thereby connecting the combined rotary shaft and the reduction member 2D. Thus, the reduction gear 300A is formed in which the motor 1A and the reduction member 2D are integrated.

[ fourth embodiment ]

The reduction gear 400 shown in fig. 16 is a fourth example of a reduction gear, and includes a motor 1 and a reduction member 2E. The motor 1 and the reduction member 2E are integrated by the connecting member 34 to form the reduction gear 400. The following description will be given of the structures different from those of the first to third embodiments, and the same reference numerals are given to the same structures as those of the reduction gear units 100, 200, 300, and detailed descriptions thereof will be omitted.

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

The third gears 30c and 31c are separate, but are connected to the speed reduction member 2E via the motor 1, and function as one gear. The third gears 30c, 31c are rotatable within bearings 38 mounted to the first motor housing 12.

The two second gears 22, 24 are each mounted on a rotary shaft 26 by means of bearings 27. The two second gears 22, 24 are rotatable about rotation shafts 26, respectively.

The first ring member 28a is in contact with one end of the rotation shaft 26, and the wheel frame 43 is in contact with the other end of the rotation shaft 26. As a result, the rotation shaft 26 is stably attached to the speed reducing member 2E as in the first embodiment. The output shaft 25 is mounted on the housing 36 via a bearing 35, and is supported on the wheel carrier 43 via a bearing 37.

As shown in fig. 17, the speed reducing member 2E of the present embodiment has two-stage planetary gear trains PGT1, PGT2, and 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, 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 a carrier 43.

The second gear 22 in the planetary gear train PGT1 of the speed reducing member 2E is capable of revolving around the third gear 30C around the central axis C on the radially inner periphery of the first gear 21, and is capable of rotating around the rotation shaft 26. In addition, the third gear 30C in the planetary gear train PGT1 can rotate or circularly move with the first rotation shaft 16 about the central axis C. The second gear 24 in the planetary gear train PGT2 of the speed reducing member 2D is capable of revolving around the third gear 31C around the central axis C on the radially inner periphery of the first gear 23, and is capable of rotating around the rotation shaft 26. In addition, the third gear 31C in the planetary gear train PGT2 can rotate or circularly move with the first rotation shaft 16 about the central axis C.

Here, the speed of the carrier 43 is determined by the planetary gear train PGT1 on the input side. In the example of fig. 16, the numbers of the third gear 31c (sun gear), the second gear 22 (planet gear), and the first gear 21 (ring gear) of the planetary gear train PGT1 are z1, z2, and z3, respectively, and the numbers of the third gear 31c (sun gear), the second gear 24 (planet gear), and the first gear 23 (ring gear) of the planetary gear train 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 number of gears of the planetary gear trains PGT1, PGT 2.

In the reduction gear 400 according to the fourth embodiment, the wheel carrier 43 is directly fixed to the rotation shaft 26, so that the stability of the rotation shaft 26 is high. Therefore, in the fourth embodiment, the second ring member 29 in the first embodiment described above does not need to be provided. Further, as the whole apparatus, a smaller number of parts is sufficient, and the thickness of the whole structure can be further reduced.

Modification of the fourth embodiment

The reduction gear 400A shown in fig. 18 is a modification of the reduction gear 400, and includes a motor 1C and a reduction member 2E. The motor 1C and the reduction member 2E are integrated by the connecting member 34 to form a reduction gear 400A. The motor 1C has a first motor housing 12 identical to the motor 1 and a second motor housing 13a identical to the motor 1A. The speed reducing member 2E has the same structure as the speed reducing member 2E of the speed reducing device 400 described above. In the motor 1C of the reduction gear 400A, the combined rotation shaft is supported by the two bearings 18 and 19, and the combined rotation shaft is supported by the two bearings 38 and 39 on the reduction member 2E side, so that the rigidity of the motor can be further improved. The coupling member 34 is inserted into a second hole (not shown) from the reduction member 2E side, and is screwed, whereby the combined rotary shaft and the reduction member 2E are coupled. Thus, the reduction gear 400A is formed in which the motor 1C and the reduction member 2E are integrated.

The present invention is not limited to the description of the first to fourth embodiments, and the motor and the speed reducing member may have other structures.

While the invention has been described with reference to specific embodiments, those skilled in the art will appreciate that these descriptions are meant to be exemplary and not limiting. Those skilled in the art can make various modifications and corrections to the present invention according to the technical ideas and principles of the present invention, and these modifications and corrections are included in the scope of the present invention.

Industrial applicability

The reduction gear of the present invention can be used in all technical fields in which a reduction gear is utilized. In particular, the present invention is widely applicable to a reduction gear in which a motor and a reduction gear are integrated, which is required to be miniaturized.

Description of the reference numerals

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

Claims (16)

1. A speed reduction device, comprising:

a motor including a first rotating shaft and a second rotating shaft that rotate about a central axis, a first rotor disposed radially outward of the first rotating shaft, a second rotor disposed radially outward of the second rotating shaft, a stator disposed between the first rotor and the second rotor, and a first motor housing disposed on one side of the first rotor in an axial direction away from the stator, and a second motor housing disposed on the other side of the second rotor in an axial direction away from the stator; and

a speed reducing member having a first gear disposed on one side in an axial direction away from the first motor housing and rotating about the central axis, a second gear engaged with the first gear, a third gear engaged with the second gear, the second gear rotatably mounted to the rotary shaft, the third gear driving rotation of the second gear, an output shaft driven by the second gear, and a carrier disposed between the output shaft and the first rotary shaft,

It is characterized in that the method comprises the steps of,

the motor has at least one bearing disposed radially outward of the first rotation shaft,

the bearing is axially located between the first rotor and the first motor housing,

the speed reducing member has at least one bearing disposed radially inward of the first gear,

the number of the first gears is at least one,

the second gear and the third gear each include two gears disposed adjacent to each other in an axial direction.

2. The reduction gear as claimed in claim 1, wherein,

the first gear includes two gears disposed adjacent to each other in an axial direction.

3. The reduction gear as claimed in claim 1 or 2, wherein,

the speed reduction member has:

a first ring member disposed between the third gear and the first motor housing; and

a second ring member disposed between the third gear and the output shaft,

the first ring member is connected to one end of the rotation shaft,

the second ring member is connected to the other end of the rotating shaft.

4. A reduction gear as claimed in any one of claims 1 to 3, wherein,

the second rotation shaft has a through hole penetrating in the axial direction, and a connecting member for connecting the first rotation shaft and the second rotation shaft is provided in the through hole.

5. The reduction gear as claimed in claim 1, wherein,

the first motor housing has a first end portion on a side in an axial direction away from the first rotor,

the bearing of the reduction member comprises a first bearing,

the first bearing is located radially inward of the third gear, and a radially inward circumferential surface of the first bearing is radially opposed to the first end portion.

6. The reduction gear according to claim 5, wherein,

the first motor housing further has a second end portion connected to the first end portion at the other side in the axial direction near the first rotor,

the bearing of the reduction member further comprises a second bearing,

the second bearing is located between the first ring member and the first motor housing, and a radially inner peripheral surface of the second bearing is radially opposed to the second convex portion.

7. The reduction gear as claimed in any one of claims 1 to 6, wherein,

the motor has a bearing on the other side of the second rotation shaft in the axial direction away from the first rotation shaft,

the second motor housing has a convex portion protruding toward one side in the axial direction,

the second rotating shaft has a recess at the end portion on the other side in the axial direction,

The bearing is disposed between an inner peripheral surface of the concave portion and an outer peripheral surface of the convex portion.

8. The reduction gear as claimed in claim 1, wherein,

the number of the second gears is at least more than two,

the two or more second gears are arranged in a circumferential direction around the central axis.

9. The reduction gear as claimed in any one of claims 1 to 8, wherein,

the first gear is a ring gear and,

the second gear is a planetary gear,

the third gear is a sun gear.

10. The reduction gear as claimed in claim 1, wherein,

the motor is an axial flux motor.

11. The reduction gear as claimed in claim 1, wherein,

the speed reduction member further includes a bearing disposed radially outward of the output shaft.

12. The reduction gear as claimed in claim 2, wherein,

a positioning portion is provided between two second gears disposed adjacent to each other in the axial direction.

13. The reduction gear as claimed in claim 1, wherein,

the radially outermost end of the first gear is located radially inward of the radially outermost end of the first motor housing.

14. The reduction gear as claimed in claim 1, wherein,

One end of the wheel frame is connected with the first rotating shaft, and the other end of the wheel frame is connected with the third gear.

15. The reduction gear as claimed in claim 2, wherein,

one end of the wheel frame is connected with the first rotating shaft, and the other end of the wheel frame is connected with the rotating shaft.

16. An electrical apparatus, wherein,

the electrical apparatus having the reduction device according to any one of claims 1 to 15.

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