Drive device

Abstract

To reduce an axial dimension of a drive device.SOLUTION: A drive device 1 includes a motor 5, a first decelerator 30, and a first brake 10. The motor 5 includes a motor shaft 6 that rotates about a rotation axis XM along a shaft direction DX. The first decelerator 30 includes a first input shaft 35 that is connected to the motor shaft 6 and rotates, and a first output unit 60 that decelerates and outputs rotation of the first input shaft 35. The first brake 10 is disposed between the motor 5 and the first decelerator 30 and applies braking force to the first input shaft 35.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a drive device.

Background Art

[0002] As disclosed in Patent Document 1, conventionally, a drive device including a motor and a speed reducer that decelerates and outputs the rotation of the motor is known. The drive device can be used to move heavy objects such as an elevator car.

[0003] Such a drive device may include a brake that stops the rotation of the speed reducer in order to hold the position of the heavy object at a predetermined position or to maintain the posture of a moving device including the drive device. Patent Document 1 discloses a drive device including a motor, a speed reducer, and a brake. The motor, the speed reducer, and the brake speed reducer are arranged in this order along the axial direction of the motor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, miniaturization of the drive device is desired. In particular, reduction of the dimensions of the drive device in the axial direction is desired.

[0006] The present invention has been made in consideration of such circumstances, and an object thereof is to reduce the axial dimension of the drive device.

Means for Solving the Problems

[0007] The present invention relates to the following <1> to <8>.

[0008] <1> A motor having a motor shaft that rotates about a rotational axis along the axial direction, a first reduction gear including a first input shaft that is connected to and rotates with the motor shaft, and a first output unit that decelerates and outputs the rotation of the first input shaft, a driving device including a first brake disposed between the motor and the first reduction gear and applying a braking force to the first input shaft.

[0009] <2> The driving device according to <1>, wherein at least a part of the first brake in the axial direction overlaps with at least a part of the motor shaft in the axial direction.

[0010] <3> The driving device according to <1> or <2>, wherein the motor includes a second brake that applies a braking force to the motor shaft.

[0011] <4> The first brake includes a solenoid that generates a magnetic force when energized, a rotating plate that is relatively rotatable with respect to the solenoid and non-rotatable with respect to the first input shaft, a fixed plate that is non-rotatable with respect to the solenoid, an armature that is movable in the axial direction, is biased by a biasing force directed in a first direction along the axial direction, is movable in a second direction opposite to the first direction by the magnetic force of the solenoid, and presses the rotating plate against the fixed plate by the biasing force or the magnetic force to apply a braking force to the first input shaft, and the driving device according to any one of <1> to <3>.

[0012] <5> The driving device according to <4>, wherein at least a part of the solenoid in the axial direction overlaps with at least a part of the motor shaft in the axial direction.

[0013] <6> The first brake includes a hub that connects the rotating plate to the first input shaft. The drive device according to <4> or <5>, wherein at least a part of the hub in the axial direction overlaps with at least a part of the motor shaft in the axial direction.

[0014] <7> The drive device according to any one of <1> to <6>, further comprising a second reduction gear having a second output portion that is connected to the first output portion and decelerates and outputs the rotation of the first output portion.

[0015] <8> The first reduction gear includes: a first case having internal teeth formed on an inner peripheral surface and arranged along a circumferential direction; a first external gear having external teeth that mesh with the internal teeth of the first case; a first shaft member that is connected to the first input shaft and eccentrically swings the first external gear; a first carrier that supports the first shaft member and relatively rotates with respect to the first case and serves as the first output portion; and includes The second reduction gear includes: a second input shaft connected to the first carrier; a second case having internal teeth formed on an inner peripheral surface and arranged along a circumferential direction; a second external gear having external teeth that mesh with the internal teeth of the second case; a second shaft member that is connected to the second input shaft and eccentrically swings the second external gear; a second carrier that supports the second shaft member and relatively rotates with respect to the second case and serves as the second output portion; and includes, the drive device according to <7>.

Advantages of the Invention

[0016] According to the present invention, the axial dimension of the drive device can be reduced.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiment for Carrying Out the Invention

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIGS. 1 to 4 are diagrams for explaining an embodiment of the present invention. In some of the diagrams, the configurations and the like shown may be omitted in other diagrams. The scales and the aspect ratios of the vertical and horizontal dimensions may be different between the diagrams.

[0019] In the present embodiment, the drive device 1 includes a motor 5, a brake 10, a first speed reducer 30, and a second speed reducer 130. The motor 5, the brake 10, the first speed reducer 30, and the second speed reducer 130 are arranged in this order along the rotation axis of the motor 5 (hereinafter, also referred to as the "motor rotation axis") XM.

[0020] The motor 5 has a motor shaft 6, a rotor and a stator (not shown), and a motor case 7 that houses a part of the motor shaft 6 and the rotor and the stator. The motor shaft 6 is connected to the first speed reducer 30. In the illustrated example, a second brake 110 is attached to the motor 5. The second brake 110 is housed in the motor case 7.

[0021] The first speed reducer 30 reduces the rotation input from the motor shaft 6 and outputs it to the second speed reducer 130. The second speed reducer 130 reduces the rotation input from the first speed reducer 30 and outputs it. The drive device 1 having such a configuration can be used for moving heavy objects such as an elevator car, a large metal door or lid. The brake 10 applies a braking force to the first speed reducer 30 and the second speed reducer 130. Thereby, the posture of the moving device including the drive device 1 can be maintained, and the heavy object can be held at a predetermined position (for example, a predetermined height position).

[0022] In the present embodiment, the first speed reducer 30 and the second speed reducer 130 are each an eccentric swing type speed reducer. An eccentric swing type speed reducer generally has a small backlash and can reduce malfunction of the entire drive device 1. Of course, the speed reducers 30; 130 are not limited to eccentric swing type speed reducers, and other types of speed reducers can also be adopted. For example, the speed reducers 30; 130 may be planetary gear type speed reducers, or may be configured by a speed reduction structure in which a planetary gear type and an eccentric swing type are combined, or may be configured by a speed reduction structure in which an eccentric swing type and a worm type are combined. Further, the speed reducers 30; 130 may be configured by any other type of speed reduction structure.

[0023] Also, in the present embodiment, the first brake 10 and the second brake 110 are electromagnetic brakes, but are not limited thereto. The brakes 10; 110 may be other types of brakes such as mechanical brakes. The brakes 10; 110 may be brakes of different types from each other.

[0024] Hereinafter, the speed reducers 30; 130 and the brakes 10; 110 will be described.

[0025] <Speed reducers 30; 130> The first speed reducer 30 includes a first input shaft 35, a first external gear 40, a first shaft member 50 that eccentrically oscillates the first external gear 40, a first carrier 60 that rotatably supports the first shaft member 50, and a substantially cylindrical first case 70. The first case 70 at least partially houses the first carrier 60. Bearings may be disposed between the first external gear 40 and the first shaft member 50, between the first carrier 60 and the first shaft member 50, and between the first case 70 and the first carrier 60. The first case 70 and the first carrier 60 are relatively rotatable about a first main rotation axis XR1. In the illustrated example, a part of the first speed reducer 30 is housed in the first housing 80. In the illustrated example, the first main rotation axis XR1 coincides with the motor rotation axis XM.

[0026] The second speed reducer 130 is configured in the same manner as the first speed reducer 30. The second speed reducer 130 includes a second input shaft 135, a second external gear 140, a second shaft member 150 that eccentrically oscillates the second external gear 140, a second carrier 160 that rotatably supports the second shaft member 150, and a substantially cylindrical second case 170. The second case 170 at least partially houses the second carrier 160. Bearings may be disposed between the second external gear 140 and the second shaft member 150, between the second carrier 160 and the second shaft member 150, and between the second case 170 and the second carrier 160. The second case 170 and the second carrier 160 are relatively rotatable about a second main rotation axis XR2. In the illustrated example, a part of the second speed reducer 130 is housed in the second housing 180. In the illustrated example, the second main rotation axis XR2 coincides with the first main rotation axis XR1 and the motor rotation axis XM. Hereinafter, a direction parallel to the rotation axes XM, XR1, XR2 and a central axis XB1 described later is referred to as an axial direction DX. Also, a direction perpendicular to the axial direction DX is referred to as a radial direction DY.

[0027] The first input shaft 35 of the first speed reducer 30 is connected to the motor shaft 6 and receives rotation input from the motor shaft 6. The first speed reducer 30 decelerates and outputs the input rotation. The first speed reducer 30 decelerates the input rotation and outputs it as the relative rotation of the first case 70 and the first carrier 60. In the illustrated example, the first case 70 is fixed to the motor case 7 via the first housing 80 and the connecting member 90. Therefore, the first carrier 60 constitutes the output portion (hereinafter also referred to as the "first output portion") of the first speed reducer 30. The first carrier 60 rotatably holds the first shaft member 50.

[0028] In the illustrated example, the second input shaft 135 of the second speed reducer 130 receives rotation input from the first carrier 60 of the first speed reducer 30. The second speed reducer 130 decelerates the input rotation and outputs it as the relative rotation of the second case 170 and the second carrier 160. In the illustrated example, the second case 170 is fixed to the motor case 7 via the second housing 180, the first case 70, the first housing 80, and the connecting member 90. Therefore, the second carrier 160 constitutes the output portion (hereinafter also referred to as the "second output portion") of the second speed reducer 130. The second carrier 160 rotatably holds the second shaft member 150.

[0029] The input shafts 35; 135 input rotation to the shaft members 50; 150, respectively. The shaft members 50; 150 each include an eccentric member 55; 155. The eccentric members 55; 155 are eccentric from the rotation centers of the shaft members 50; 150. The external gear wheels 40; 140 are each penetrated by the shaft members 50; 150. The external gear wheels 40; 140 are located on the eccentric members 55; 155. As the shaft members 50; 150 rotate, the external gear wheels 40; 140 perform eccentric oscillation. The external gear wheels 40; 140 have external teeth 45; 145. Internal teeth 75; 175 are provided on the inner surfaces of the cases 70; 170. The external teeth 45; 145 and the internal teeth 75; 175 are arranged in the circumferential direction of a circle centered on the main rotation axes XR1; XR2. The external teeth 45; 145 mesh with the internal teeth 75; 175. The number of the external teeth 45; 145 is different from the number of the internal teeth 75; 175. When rotation is input to the shaft members 50; 150, the external gear wheels 40; 140 perform eccentric oscillation so that the internal teeth 75; 175 and the external teeth 45; 145 mesh with each other. Due to the difference between the number of the internal teeth 75; 175 and the number of the external teeth 45; 145, the carriers 60; 160 that support the external gear wheels 40; 140 and the shaft members 50; 150 rotate relative to the cases 70; 170.

[0030] Hereinafter, the carrier 60; 160, the shaft member 50; 150, and the external gear wheel 40; 140 will be described in detail in order with respect to the illustrated specific configurations.

[0031] As shown well in FIG. 3, the carriers 60; 160 are held in the cases 70; 170 via a pair of main bearings 32; 132. The carriers 60; 160 are rotatable with respect to the cases 70; 170 about the main rotation axes XR1; XR2. The illustrated carriers 60; 160 have carrier bases 61; 161 and carrier plates 62; 162 fixed to each other. The carrier bases 61; 161 and the carrier plates 62; 162 can be fixed to each other using fixtures such as bolts. The carrier base 61; 161 includes a base plate portion 61a; 161a on a disk and a plurality of pillar portions 61b; 161b protruding in the axial direction DX from the base plate portion 61a; 161a. The base plate portion 61a; 161a and the plurality of pillar portions 61b; 161b may be integrally formed. The plurality of pillar portions 61b; 161b may be provided at equal intervals in the circumferential direction of a circle centered on the main rotation axes XR1; XR2. In the illustrated specific example, two or three pillar portions 61b; 161b are provided for each speed reducer 30; 130. In the illustrated example, the first carrier 60 of the first speed reducer 30 includes two pillar portions 61b, and the second carrier 160 of the second speed reducer 130 includes three pillar portions 161b.

[0032] The illustrated carriers 60; 160 are provided with central holes 64; 164. The central holes 64; 164 penetrate the carrier bases 61; 161 and the carrier plates 62; 162. The central holes 64; 164 are located on the main rotation axes XR1; XR2. An input shaft 35; 135 extends into the central holes 64; 164.

[0033] As shown in FIG. 2, the carriers 60; 160 are further provided with a plurality of through holes 65; 165 corresponding to the plurality of shaft members 50; 150. Each through hole 65; 165 penetrates the carrier bases 61; 161 and the carrier plates 62; 162. The plurality of through holes 65; 165 are positioned at equal intervals in the circumferential direction of a circle centered on the main rotation axes XR1; XR2. Each shaft member 50; 150 extends through the corresponding through hole 65; 165.

[0034] As shown in FIG. 2, the shaft members 50; 150 are rotatably held by the carriers 60; 160. The shaft members 50; 150 are rotatable about the rotation axes XA1; XA2 with respect to the carriers 60; 160. The rotation axes XA1; XA2 are parallel to the axial direction DX. The illustrated speed reducers 30; 130 include a plurality of shaft members 50; 150. The plurality of shaft members 50; 150 are respectively inserted into the corresponding through holes 65; 165 of the carriers 60; 160. The plurality of shaft members 50; 150 are positioned at equal intervals in the circumferential direction of a circle centered on the main rotation axes XR1; XR2. In the illustrated example, each speed reducer 30; 130 is provided with two or three shaft members 50; 150. Correspondingly, each carrier 60; 160 is provided with two or three through holes 65; 165. In the illustrated example, the first speed reducer 30 includes two shaft members 50, and the second speed reducer 130 includes three shaft members 150.

[0035] The illustrated shaft members 50; 150 include a shaft main body portion 51; 151 and a pair of eccentric members 55; 155 located on the shaft main body portion 51; 151. The eccentric members 55; 155 are columnar portions. The eccentric members 55; 155 have a diameter larger than that of the shaft main body portion 51; 151. The eccentric members 55; 155 are eccentric from the rotation axes XA1; XA2 which are the rotation centers of the shaft members 50; 150. The pair of eccentric members 55; 155 includes an eccentric member 55A; 155A and an eccentric member 55B; 155B. The eccentric member 55A; 155A and the eccentric member 55B; 155B are eccentric by the same amount on the opposite side from the rotation axes XA1; XA2. In other words, in a cross section perpendicular to the axial direction DX, the centers of the eccentric member 55A; 155A and the eccentric member 55B; 155B are at point-symmetrical positions centered on a point on the rotation axes XA1; XA2.

[0036] The shaft main body 51; 151 has a first bearing support portion 52a; 152a that serves as an insertion portion into the carrier base 61; 161 and a second bearing support portion 52b; 152b that serves as an insertion portion into the carrier plate 62; 162. The bearing support portion 52a; 152a supports the base plate portion 61a; 161a via a bearing. The bearing support portion 52b; 152b supports the carrier plate 62; 162 via a bearing. The pair of eccentric bodies 55A, 55B; 155A, 155B are located between the pair of bearing support portions 52a, 52b; 152a, 152b in the axial direction DX.

[0037] The illustrated shaft member 50; 150 further includes an input gear 59; 159 fixed to the shaft main body 51; 151. The rotation of the input shaft 35; 135 is input to the input gear 59; 159. More specifically, the input gear 59; 159 meshes with a gear provided on the outer peripheral portion of the input shaft 35; 135 and rotates with the rotation of the input shaft 35; 135. In the illustrated example, the input gear 59; 159, the first bearing support portion 52a; 152a, the eccentric body 55A; 155A, the eccentric body 55B; 155B, and the second bearing support portion 52b; 152b are located in this order along the axial direction DX.

[0038] The illustrated speed reducer 30; 130 has external gear wheels 40; 140, namely, an external gear wheel 40A; 140A and an external gear wheel 40B; 140B. The external gear wheel 40A; 140A is located on the eccentric body 55A; 155A of a plurality of shaft members 50; 150. The external gear wheel 40B; 140B is located on the eccentric body 55B; 155B of a plurality of shaft members 50; 150. The external gear wheel 40A; 140A and the external gear wheel 40B; 140B are located between the base plate portion 61a; 161a of the carrier base 61; 161 and the carrier plate 62; 162 in the axial direction DX.

[0039] The illustrated external gear 40; 140 includes a disk-shaped central plate portion 41; 141 and external teeth 45; 145 arranged at the peripheral edge of the central plate portion 41; 141. The central plate portion 41; 141 is provided with a central hole 42a; 142a and a pillar portion through-hole 42b; 142b. The central hole 42a; 142a is located on the main rotation axis XR1; XR2. The central hole 42a; 142a faces the central hole 64; 164 in the axial direction DX. In the illustrated example, a plurality of pillar portion through-holes 42b; 142b are located at equal intervals in the circumferential direction of a circle centered on the central hole 42a; 142a. The pillar portions 61b; 161b of the carrier 60; 160 penetrate through the pillar portion through-holes 42b; 142b. In the illustrated specific example, corresponding to the number of the pillar portions 61b; 161b, the central plate portion 41; 141 is provided with two or three pillar portion through-holes 42b; 142b.

[0040] As shown in FIG. 2, the central plate portion 41; 141 is further provided with holes 43; 143. In the illustrated example, corresponding to the number of the shaft members 50; 150, two or three holes 43; 143 are located at equal intervals in the circumferential direction of a circle centered on the central hole 42a; 142a. Eccentric members 55; 155 are arranged in the holes 43; 143. A bearing is provided between the eccentric members 55; 155 and the external gear 40; 140. The external gears 40A; 140A are supported on the eccentric members 55A; 155A of the shaft members 50; 150 via bearings. The external gears 40B; 140B are supported on the eccentric members 55B; 155B of the shaft members 50; 150 via bearings.

[0041] Each external gear 40; 140 is supported by two or three eccentric members 55; 155. The eccentric members 55; 155 included in the two or three shaft members 50; 150 are in phase alignment. Therefore, when the two or three shaft members 50; 150 rotate, the external gear 40; 140 eccentrically oscillates. In other words, when the two or three shaft members 50; 150 rotate, the external gear 40; 140 translates in the circumferential direction of a circle centered on the main rotation axis XR1; XR2. The external gears 40A; 140A and the external gears 40B; 140B operate with a half-phase shift.

[0042] When rotation is input to the input shafts 35; 135 of the speed reducers 30; 130 having the above-described configuration, the shaft members 50; 150 rotate together with the input gears 59; 159, and the external gear 40; 140 swings eccentrically. At this time, the external teeth 45; 145 of the external gear 40; 140 mesh with the internal teeth 75; 175 of the case 70; 170. Due to the difference in the number of teeth between the external teeth 45; 145 and the internal teeth 75; 175, the carrier 60; 160 that supports the external gear 40; 140 via the shaft member 50; 150 and the case 70; 170 rotate relative to each other about the main rotation axes XR1; XR2. When the case 70; 170 is fixed, the rotation of the carrier 60; 160 is output. When the carrier 60; 160 is fixed, the rotation of the case 70; 170 is output. In the illustrated example, since the case 70; 170 is fixed, the rotation of the carrier 60; 160 is output.

[0043] Next, the brakes 10; 110 will be described. In the illustrated example, the first brake 10 applies a braking force to the first input shaft 35 of the first speed reducer 30. The second brake 110 applies a braking force to the motor shaft 6.

[0044] In the example shown in FIG. 4, the brakes 10; 110 are non-energized actuating type electromagnetic brakes. The non-energized actuating type electromagnetic brakes 10; 110 are in an actuated state when not energized and in a non-actuated state when energized. The brakes 10; 110 apply a braking force to the first input shaft 35 or the motor shaft 6 in the actuated state. The brakes 10; 110 release the first input shaft 35 or the motor shaft 6 in the non-actuated state. Therefore, when the first brake 10 is in the non-actuated state, the first input shaft 35 can rotate without receiving a braking force. Also, when the second brake 110 is in the non-actuated state, the motor shaft 6 can rotate without receiving a braking force.

[0045] Power supply to the first brake 10 and the second brake 110 is performed in synchronization with the power supply to the motor 5. When the motor 5 is energized, the brakes 10; 110 are also energized. When the motor 5 is de-energized, the brakes 10; 110 are also de-energized. Therefore, when the motor 5 is energized, the brakes 10; 110 are in a non-operating state, and the first input shaft 35 and the motor shaft 6 can rotate without being subject to the braking force of the brakes 10; 110. On the other hand, when the motor 5 is de-energized, the brakes 10; 110 are in an operating state, and a braking force is applied to the first input shaft 35 and the motor shaft 6. By providing the drive device 1 with two brakes 10; 110, even if one brake fails, the other brake can be operated. For this reason, even if one brake fails, the heavy object can be held at a predetermined position.

[0046] As shown in FIG. 4, the brakes 10; 110 include hubs 11; 111, rotating plates 12; 112, solenoids 13; 113, yokes 14; 114, fixed plates 18; 118, and armatures 19; 119. These elements constituting the brakes 10; 110 are arranged around the central axes XB1; XB2.

[0047] The hub 11 of the first brake 10 is connected to the first input shaft 35. The hub 11 is non-rotatable relative to the first input shaft 35 and rotates together with the first input shaft 35. The hub 111 of the second brake 110 is connected to the motor shaft 6. The hub 111 is non-rotatable relative to the motor shaft 6 and rotates together with the motor shaft 6. More specifically, the hubs 11; 111 have a cylindrical shape. The hubs 11; 111 have central holes 11a; 111a. The central holes 11a; 111a are located on the central axes XB1; XB2. By inserting the first input shaft 35 or the motor shaft 6 into the central holes 11a; 111a, the hubs 11; 111 are connected to the first input shaft 35 or the motor shaft 6.

[0048] The rotating plates 12; 112 are connected to the hubs 11; 111. In other words, the rotating plate 12 of the first brake 10 is connected to the first input shaft 35 via the hub 11. Also, the rotating plate 112 of the second brake 110 is connected to the motor shaft 6 via the hub 111. The rotating plates 12; 112 are disk-shaped. The rotating plates 12; 112 are connected to the outer peripheral surfaces of the hubs 11; 111 at their inner peripheral portions. The rotating plates 12; 112 are non-rotatable relative to the hubs 11; 111 and rotate together with the hubs 11; 111 (and thus together with the first input shaft 35 or the motor shaft 6). The rotating plates 12; 112 may be integrally formed with the hubs 11; 111.

[0049] The solenoids 13; 113 are coils that are excited when energized. In the illustrated example, the brakes 10; 110 include a plurality of solenoids 13; 113. The plurality of solenoids 13; 113 are arranged so as to surround the central axes XB1; XB2. The solenoids 13; 113 may receive power supply from a power supply device common to the motor 5.

[0050] The yokes 14; 114 house the solenoids 13; 113. The yokes 14; 114 have cylindrical outer wall portions 15; 115, cylindrical inner wall portions 16; 116, and disk-shaped bottom wall portions 17; 117. The inner wall portions 16; 116 are located inside the outer wall portions 15; 115. The solenoids 13; 113 are housed between the outer wall portions 15; 115 and the inner wall portions 16; 116. The bottom wall portions 17; 117 connect one end of the outer wall portions 15; 115 and one end of the inner wall portions 16; 116. The yokes 14; 114 have central holes 14a; 114a. The central holes 14a; 114a are located on the central axes XB1; XB2. The first input shaft 35 or the motor shaft 6 is inserted into the central holes 14a; 114a. The yokes 14; 114 are non-rotatable relative to the motor case 7. The yoke 14 of the first brake 10 is fixed to the motor case 7 and the first housing 80 of the first speed reducer 30 via the connecting member 90.

[0051] The fixed plates 18; 118 are axially spaced from the yokes 14; 114 in the axial direction DX. A rotating plate 12; 112 and an armature 19; 119 are disposed between the fixed plate 18; 118 and the yoke 14; 114. The fixed plate 18; 118, the rotating plate 12; 112, the armature 19; 119, and the yoke 14; 114 are arranged in this order in the axial direction DX.

[0052] The fixed plate 18; 118 is fixed to the yoke 14; 114 via a spacer 20; 120. The fixed plate 18; 118 is disk-shaped and has a central hole 18a; 118a. A hub 11; 111 is inserted into the central hole 18a; 118a. The hub 11; 111 is rotatable relative to the fixed plate 18; 118.

[0053] The armature 19; 119 is disposed between the rotating plate 12; 112 and the solenoid 13; 113. The armature 19; 119 is disk-shaped and has a central hole 19a; 119a. The central hole 19a; 119a is located on the central axis XB1; XB2. The armature 19; 119 is supported by a spacer 20; 120. More specifically, through holes 19b; 119b are formed in the armature 19; 119. A spacer 20; 120 is inserted into the through holes 19b; 119b. The armature 19; 119 is movable in the axial direction DX.

[0054] The armature 19; 119 is biased in the first direction D1 by a biasing member (not shown). The first direction D1 is a direction along the axial direction DX and is a direction toward the rotating plate 12; 112. That is, the armature 19; 119 is biased toward the rotating plate 12; 112. For this reason, when the solenoid 13; 113 is not energized, the armature 19; 119 presses the rotating plate 12; 112 against the fixed plate 18; 118. Thereby, a braking force is applied to the rotating plate 12; 112 from the fixed plate 18; 118 and the armature 19; 119. On the other hand, when the solenoid 13; 113 is energized, a magnetic attraction force of the solenoid 13; 113 acts on the armature 19; 119 in the second direction D2. The second direction D2 is a direction along the axial direction DX and is a direction toward the solenoid 13; 113. That is, the armature 19; 119 is attracted to the solenoid 13; 113.

[0055] Note that a biasing member 21; 121 is provided between the rotating plate 12; 112 and the fixed plate 18; 118. A biasing member 22; 122 is provided between the rotating plate 12; 112 and the armature 19; 119. The biasing member 21; 121 biases the rotating plate 12; 112 in the second direction D2. In other words, the biasing member 21; 121 biases the rotating plate 12; 112 in a direction to separate it from the fixed plate 18; 118. The biasing member 22; 122 biases the rotating plate 12; 112 in the first direction D1. In other words, the biasing member 22; 122 biases the rotating plate 12; 112 in a direction to separate it from the armature 19; 119. For this reason, when the solenoid 13; 113 is energized and the armature 19; 119 is attracted to the solenoid 13; 113, the rotating plate 12; 112 separates from the fixed plate 18; 118 and the armature 19; 119. As a result, when the solenoid 13; 113 is energized, no braking force is applied to the rotating plate 12; 112 from the fixed plate 18; 118 and the armature 19; 119.

[0056] The brakes 10; 110 having the above configuration, when the solenoids 13; 113 are energized, the armatures 19; 119 are attracted to the solenoids 13; 113, so that the rotating plates 12; 112 and the hubs 11; 111 can rotate without receiving braking force from the fixed plates 18; 118 and the armatures 19; 119. As a result, the first input shaft 35 or the motor shaft 6 can rotate without receiving braking force from the brakes 10; 110.

[0057] On the other hand, when the solenoids 13; 113 are not energized, since the magnetic attraction force of the solenoids 13; 113 does not occur, the armatures 19; 119 press the rotating plates 12; 112 against the fixed plates 18; 118 as described above. As a result, braking force is applied to the rotating plates 12; 112 and the hubs 11; 111 from the fixed plates 18; 118 and the armatures 19; 119, and unintended rotation of the first input shaft 35 or the motor shaft 6 is prevented.

[0058] Next, the connection mode between the first speed reducer 30 and the first brake 10 will be described. In the drive device 1 of the present embodiment, as shown in FIG. 1, the first brake 10 is disposed between the motor 5 and the first speed reducer 30. The first input shaft 35 of the first speed reducer 30 extends through the central holes 11a; 19a; 14a of the first brake 10 and is connected to the motor shaft 6. An insertion hole 35a for inserting the motor shaft 6 is formed in the first input shaft 35. The insertion hole 35a is open at the end of the first input shaft 35 on the side facing the motor case 7. The motor shaft 6 is inserted from the side of the end of the first input shaft 35. The first speed reducer 30 and the motor 5 are connected by a connecting member 90.

[0059] Since the first brake 10 is disposed between the motor 5 and the first speed reducer 30, the positions of the first housing 80 and / or the connecting member 90 of the first speed reducer 30 in the axial direction DX can be overlapped with the position of the first brake 10 in the axial direction DX. In other words, when viewed in the radial direction DY, the first housing 80 and / or the connecting member 90 of the first speed reducer 30 and the first brake 10 can be arranged so as to overlap each other. Thereby, the dimension in the axial direction DX of the region occupied by the first speed reducer 30 and / or the connecting member 90 and the brake 10 in the drive device 1 can be reduced. Therefore, the dimension of the drive device 1 in the axial direction DX can be reduced. In the example shown in FIG. 1, a part of the first brake 10 is housed in the first housing 80, and the other part is housed in the connecting member 90.

[0060] Furthermore, in the drive device 1 of the present embodiment, at least a part of the motor shaft 6 extends inside the first brake 10. In other words, the position of at least a part of the motor shaft 6 in the axial direction DX overlaps with the position of at least a part of the first brake 10 in the axial direction DX. Further in other words, when viewed in the radial direction DY, at least a part of the motor shaft 6 and at least a part of the first brake 10 overlap each other.

[0061] Here, conventionally, as shown in FIG. 5, in a drive device including a speed reducer, a motor, and a brake, the positions in the axial direction of the speed reducer, the motor, and the brake did not overlap. On the other hand, in the present embodiment, the positions of at least a part of the motor shaft 6 and at least a part of the first brake 10 in the axial direction DX overlap each other. Thereby, the dimension in the axial direction DX of the region occupied by the motor 5 and the brake 10 in the drive device 1 can be reduced. Therefore, the dimension of the drive device 1 in the axial direction DX can be reduced.

[0062] Furthermore, in the illustrated example, at least a part of the motor shaft 6 extends within the solenoid 13 of the first brake 10. In other words, the position of at least a part of the motor shaft 6 in the axial direction DX overlaps with the position of at least a part of the solenoid 13 in the axial direction DX. Stated yet another way, when viewed in the radial direction DY, at least a part of the motor shaft 6 and at least a part of the solenoid 13 overlap. Thereby, the dimension in the axial direction DX of the region occupied by the motor 5 and the brake 10 in the drive device 1 can be effectively reduced. Therefore, the dimension of the drive device 1 in the axial direction DX can be effectively reduced.

[0063] Although one embodiment has been described with reference to a specific example, the above example is not intended to limit one embodiment. The above-described one embodiment can be implemented with various other specific examples, and various omissions, replacements, changes, and additions can be made without departing from the gist thereof.

[0064] For example, the motor shaft 6 may extend into the hub 11 or the rotating plate 12 of the first brake 10. In other words, the position of at least a part of the motor shaft 6 in the axial direction DX may overlap with the position of at least a part of the hub 11 or the rotating plate 12 in the axial direction DX. Stated yet another way, when viewed in the radial direction DY, at least a part of the motor shaft 6 and at least a part of the hub 11 or the rotating plate 12 of the first brake 10 may overlap. In this case, the dimension in the axial direction DX of the region occupied by the motor 5 and the first brake 10 in the drive device 1 can be further effectively reduced. Therefore, the dimension of the drive device 1 in the axial direction DX can be further effectively reduced.

[0065] Also, in the above-described embodiments, the carriers 60; 160 constitute the output portions of the speed reducers 30; 130, but the present invention is not limited to this. The cases 70; 170 may constitute the output portions of the speed reducers 30; 130. When the first case 70 constitutes the output portion of the first speed reducer 30, the first carrier 60 may be fixed to the motor case 7. In this case, the second input shaft 135 may be connected to the first case 70. Also, when the second case 170 constitutes the output portion of the second speed reducer 130, the second carrier 160 may be fixed to the motor case 7.

[0066] Also, the drive device 1 may not include a plurality of speed reducers 30; 130. The drive device 1 may not include the second speed reducer 130. In this case, the output portion 60 or 70 of the first speed reducer 30 may constitute the output portion of the drive device 1.

[0067] According to the above-described embodiment and its modification, the drive device 1 includes the motor 5, the first speed reducer 30, and the first brake 10. The motor 5 has a motor shaft 6 that rotates about a rotation axis XM along the axial direction DX. The first speed reducer 30 has a first input shaft 35 that is connected to the motor shaft 6 and rotates, and a first output portion 60 that reduces and outputs the rotation of the first input shaft 35. The first brake 10 is disposed between the motor 5 and the first speed reducer 30 and applies a braking force to the first input shaft 35. According to such a drive device 1, the dimension of the drive device 1 in the axial direction DX can be reduced.

[0068] In the above-described embodiment and its modification, at least a part of the position of the first brake 10 in the axial direction overlaps with at least a part of the position of the motor shaft 6 in the axial direction. In this case, the dimension of the drive device 1 in the axial direction DX can be effectively reduced.

[0069] In the above-described embodiment and its modification, at least a part of the solenoid 13 of the first brake 10 overlaps with at least a part of the motor shaft 6 in the axial direction. In this case, the dimension of the drive device 1 in the axial direction DX can be effectively reduced.

[0070] In the modification described above, at least a part of the hub 11 of the first brake 10 overlaps with at least a part of the motor shaft 6 in the axial direction. In this case, the dimension of the drive device 1 in the axial direction DX can be effectively reduced.

[0071] In the above-described embodiment and its modification, the motor 5 includes a second brake 110 that applies a braking force to the motor shaft 6. In this case, even if one of the brakes 10 and 110 fails, the other of the brakes 10 and 110 can apply a braking force to the first input shaft 35.

[0072] In the above-described embodiment and its modification, the first brake 10 includes a solenoid 13, a rotating plate 12, a fixed plate 18, and an armature 19. The solenoid 13 generates a magnetic force when energized. The rotating plate 12 is relatively rotatable with respect to the solenoid 13 and non-rotatable with respect to the first input shaft 35. The fixed plate 18 is non-rotatable with respect to the solenoid 13. The armature 19 is movable in the axial direction DX. The armature 19 is biased by a biasing force directed in the first direction D1 along the axial direction DX. The armature 19 is also movable in the second direction D2 opposite to the first direction D1 by the magnetic force of the solenoid 13. The armature 19 presses the rotating plate 12 against the fixed plate 18 by the biasing force or the magnetic force to apply a braking force to the first input shaft 35. In this case, a braking force can be applied to the first input shaft 35 corresponding to the presence or absence of power supply to the solenoid 13.

[0073] In the above-described embodiment and its modifications, the drive device 1 further includes a second speed reducer 130. The second speed reducer 130 is connected to the first output portion 60 of the first speed reducer 30. The second speed reducer 130 has a second output portion 160 that decelerates and outputs the rotation of the first output portion 60. In this case, the drive device 1 can be used to move heavy objects such as an elevator car, a large metal door, or a lid.

[0074] In the above-described embodiment and its modifications, the first speed reducer 30 includes a first case 70, a first external gear 40, a first shaft member 50, and a first carrier 60 as a first output portion. Inner teeth 75 arranged along the circumferential direction are formed on the inner circumferential surface of the first case 70. The first external gear 40 has external teeth 45 that mesh with the inner teeth 75 of the first case 70. The first shaft member 50 is connected to the first input shaft 35 and eccentrically oscillates the first external gear 40. The first carrier 60 supports the first shaft member 50 and rotates relative to the first case 70. The second speed reducer 130 includes a second input shaft 135, a second case 170, a second external gear 140, a second shaft member 150, and a second carrier 160 as a second output portion. The second input shaft 135 is connected to the first carrier 60. Inner teeth 175 arranged along the circumferential direction are formed on the inner circumferential surface of the second case 170. The second external gear 140 has external teeth 145 that mesh with the inner teeth 175 of the second case 170. The second shaft member 150 is connected to the second input shaft 135 and eccentrically oscillates the second external gear 140. The second carrier 160 supports the second shaft member 150 and rotates relative to the outer cylinder of the second case 170. In this case, it is possible to reduce malfunction of the entire drive device 1.

[0075] Although some modifications to the above-described embodiment have been described above, of course, it is also possible to appropriately combine and apply a plurality of modifications.

Explanation of Reference Numerals

[0076] 1: Driving device, 5: Motor, 6: Motor shaft, 10: First brake, 11: First hub, 12: First rotating plate, 13: First solenoid, 18: Fixed plate, 19: Armature, 30: First speed reducer, 110: Second brake, 130: Second speed reducer

Claims

1. A motor having a motor shaft that rotates about a rotational axis along the axial direction, a first reduction gear having a first input shaft that is connected to and rotates with the motor shaft, and a first output portion that decelerates and outputs the rotation of the first input shaft, a drive device disposed between the motor and the first reduction gear and including a first brake that applies a braking force to the first input shaft.

2. The drive device according to claim 1, wherein at least a part of the first brake in the axial direction overlaps with at least a part of the motor shaft in the axial direction.

3. The drive device according to claim 1, wherein the motor includes a second brake that applies a braking force to the motor shaft.

4. The first brake includes a solenoid that generates a magnetic force when energized, a rotating plate that is relatively rotatable with respect to the solenoid and non-rotatable relative to the first input shaft, a fixed plate that is non-rotatable relative to the solenoid, and an armature that is movable in the axial direction, is biased by a biasing force directed in a first direction along the axial direction, is movable in a second direction opposite to the first direction by the magnetic force of the solenoid, and presses the rotating plate against the fixed plate by the biasing force or the magnetic force to apply a braking force to the first input shaft. The drive device according to claim 1.

5. The drive device according to claim 4, wherein at least a part of the solenoid in the axial direction overlaps with at least a part of the motor shaft in the axial direction.

6. The first brake includes a hub that connects the rotating plate to the first input shaft, The drive device according to claim 4, wherein at least a part of the hub in the axial direction overlaps with at least a part of the motor shaft in the axial direction.

7. The drive device according to claim 1, further comprising a second reduction gear connected to the first output portion and having a second output portion that decelerates and outputs the rotation of the first output portion.

8. The first reduction gear includes a first case having internal teeth formed on an inner peripheral surface and arranged along the circumferential direction, a first external gear having external teeth that mesh with the internal teeth of the first case, and a first shaft member connected to the first input shaft and eccentrically oscillating the first external gear. a first carrier as the first output portion that supports the first shaft member and rotates relative to the first case; including; the second speed reducer; a second input shaft connected to the first carrier; a second case having internal teeth formed on an inner peripheral surface thereof and arranged along a circumferential direction; a second external gear having external teeth meshing with the internal teeth of the second case; a second shaft member connected to the second input shaft and eccentrically swinging the second external gear; a second carrier as the second output portion that supports the second shaft member and rotates relative to the second case; The drive device according to claim 7, including the above.

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