Transmission device, electric drive device, and vehicle-mounted system

Abstract

A transmission device (50) is provided with: an input shaft (70b); an output shaft (72b) extending in a direction in which the input shaft extends; a transmission mechanism (70a, 71a, 72a) that changes the rotational speed of the input shaft and transmits the rotational speed to the output shaft; a housing (60) that accommodates the input shaft, the output shaft, and the transmission mechanism; and a brake mechanism (80) that applies a brake torque to at least one of the input shaft and the output shaft. The brake mechanism is accommodated in the housing.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese application No. 2022-154091 filed on September 27, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a transmission device, an electric drive device having the transmission device, and a vehicle-mounted system having the electric drive device. Background Art

[0004] Conventionally, as described in Patent Document 1, a speed change device integrated with an electric motor is known.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6148509

[0008] The speed change device includes an input shaft, an output shaft extending in the direction in which the input shaft extends, and a speed change mechanism that changes the rotation speed of the input shaft and transmits the speed to the output shaft. The input shaft, the output shaft, and the speed change mechanism are housed in a housing of the speed change device.

[0009] Sometimes a brake mechanism is required to apply a braking force to at least one of the input shaft and the output shaft of the transmission. If the transmission is provided with a brake mechanism, there is a concern that the size of the transmission will increase. Summary of the invention

[0010] A main object of the present disclosure is to provide a transmission device capable of minimizing the increase in size of the device, an electric drive device including the transmission device, and an in-vehicle system including the electric drive device.

[0011] The present disclosure comprises: an input shaft;

[0012] an output shaft extending in a direction in which the input shaft extends;

[0013] a speed change mechanism that changes the speed of the input shaft and transmits it to the output shaft;

[0014] a housing that accommodates the input shaft, the output shaft, and the speed change mechanism; and

[0015] a brake mechanism that applies a braking torque to at least one of the input shaft and the output shaft,

[0016] The brake mechanism is accommodated in the housing.

[0017] This can minimize the increase in size of the transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the attached drawings. These drawings are as follows:

[0019] Figure 1 It is a diagram showing the overall structure of an automated guided vehicle according to an embodiment.

[0020] Figure 2 It is a side view of the automated guided vehicle.

[0021] Figure 3 It is a three-dimensional diagram of the reduction gear.

[0022] Figure 4 This is a diagram showing the internal structure of the motor and the reduction gear.

[0023] Figure 5 It is a diagram showing the internal structure of the reduction gear transmission in a state where the second case member and the third case member are removed.

[0024] Figure 6 It is a diagram showing the internal structure of the reduction gear transmission in a state where the third case member is removed.

[0025] Figure 7 It is a diagram showing the internal structure of the reduction gear transmission in a state where the third case member is removed.

[0026] Figure 8 It is a diagram showing a drum brake mechanism.

[0027] Fig. 9 It is a diagram showing a drum brake mechanism in a braking operation state.

[0028] Fig.10 It is a diagram showing a drum brake mechanism in a brake non-actuated state.

[0029] Fig.11 This is a diagram showing the vicinity of the solenoid coil inside the housing as viewed from above.

[0030] Fig.12 It is a diagram showing the overall structure of an automated guided vehicle according to another embodiment.

[0031] Fig.13 It is a side view of an automated guided vehicle according to another embodiment. DETAILED DESCRIPTION

[0032] Hereinafter, an embodiment of a speed change device and an electric drive device having a speed change device according to the present disclosure will be described with reference to the accompanying drawings. The electric drive device is applied to small mobility. The small mobility of the present embodiment is a vehicle that travels at a low speed, for example, below 10 km / h. Specifically, the small mobility is an unmanned transport vehicle of an electric vehicle used for transporting articles in a workplace such as a production line or a warehouse in a factory, and more specifically, an AGV (Automatic Guided Vehicle).

[0033] like Figure 1 and Figure 2 As shown, the unmanned guided vehicle 10 includes a vehicle body 11 and a plurality of drive wheels 12. In this embodiment, the plurality of drive wheels 12 are a right front wheel 12FR, a left front wheel 12FL arranged in parallel with the right front wheel 12FR in the vehicle width direction, a right rear wheel 12RR, and a left rear wheel 12RL arranged in parallel with the right rear wheel 12RR in the vehicle width direction. That is, the unmanned guided vehicle 10 includes two sets of right drive wheels and left drive wheels. Figure 2 In FIG. 1 , for convenience, only the structure of the right driving wheel among the left and right driving wheels is shown.

[0034] The vehicle body 11 is a structure in which the dimension in the vehicle length direction is larger than the dimension in the vehicle width direction. The upper surface of the vehicle body 11 is a loading surface 11a on which the transported object is loaded. The loading surface 11a is substantially parallel to the road surface GL on which the automated guided vehicle 10 travels. Figure 1 In FIG. 1 , the outer peripheral edge of the vehicle body 11 is depicted by a dotted line, and a portion of the structure below the mounting surface 11 a of the vehicle body 11 is depicted by a solid line.

[0035] The vehicle body 11 includes, as a vehicle-mounted system, an electric drive device 20 for rotating the drive wheels 12 to drive the unmanned guided vehicle 10, a steering mechanism 13 for steering the drive wheels 12, a host ECU (not shown) for controlling the travel of the unmanned guided vehicle 10, and a power storage unit (not shown) that serves as a power source for the electric drive device 20 and the host ECU. The power storage unit is, for example, a secondary battery such as a lithium-ion battery. The power storage unit is, for example, provided at the lower portion of the vehicle body 11.

[0036] The electric drive device 20 is provided corresponding to each drive wheel 12. In the present embodiment, each electric drive device 20 has basically the same structure. The electric drive device 20 includes a motor 30 as a rotational power source for the drive wheel 12 and a reduction device 50 that amplifies the output torque of the motor 30 and transmits it to the drive wheel 12.

[0037] First, use Figure 4 The electric motor 30 will be described. Figure 4 It is a longitudinal overall view of the motor 30 and the reduction gear device 50 .

[0038] The motor 30 includes a rotor 31 including an excitation pole (e.g., a permanent magnet), a shaft 32 fixed to the rotor 31, and a stator 33 arranged radially outwardly relative to the rotor 31. The rotation center axis of the shaft 32 extends in the horizontal direction. The stator 33 includes a stator core (not shown) and a stator winding (not shown) wound around the stator core.

[0039] The motor 30 includes a motor housing 34. The motor housing 34 includes a tubular portion 35, a first connecting portion 36, a second connecting portion 37, and a cover portion 38. The tubular portion 35 is in the shape of a tube that is longer in the direction in which the shaft 32 extends, and specifically, is in the shape of a cylinder. The first connecting portion 36 is provided on the first end side of the two ends in the long side direction of the tubular portion 35, and the second connecting portion 37 is provided on the second end side. The rotor 31 and the stator 33 are accommodated in the cylindrical space surrounded by the tubular portion 35, the first connecting portion 36, and the second connecting portion 37. The stator 33 is provided on the inner circumferential surface of the tubular portion 35. In addition, the cross section of the motor housing 34 is not limited to a cylindrical shape, and for example, the cross section may also be a rectangular shape.

[0040] A first opening 36a is formed in the first connection portion 36. A first motor bearing 39 is provided in the first opening 36a. In addition, a second opening 37a is formed in the second connection portion 37, and a second motor bearing 40 is provided in the second opening 37a. In the present embodiment, each bearing 39, 40 is a rolling bearing having an inner ring, an outer ring, and rolling elements provided between the inner ring and the outer ring. The first end side of the shaft 32 is rotatably supported by the first motor bearing 39, and the second end side of the shaft 32 is rotatably supported by the second motor bearing 40.

[0041] A cover portion 38 is provided on the side opposite to the tubular portion 35 in the long side direction of the motor housing 34 in the second connection portion 37. A control substrate 41 is arranged in the space surrounded by the second connection portion 37 and the cover portion 38. In the present embodiment, the control substrate 41 is arranged in such a manner that the plate surface of the control substrate 41 is orthogonal to the extension direction of the shaft 32. An inverter electrically connected to the stator winding and a motor ECU as a control unit are provided on the control substrate 41. The inverter has semiconductor switches of the upper arm and the lower arm of three phases. The inverter converts the direct current supplied from the power storage unit of the unmanned guided vehicle 10 into alternating current and supplies it to the stator winding by switching control of the semiconductor switches of the upper arm and the lower arm. The motor ECU is mainly composed of a microcomputer. The motor ECU performs switching control of the inverter to control the control amount (for example, torque) of the motor 30 to the command value sent from the upper ECU.

[0042] Next, use Figure 3 to Figure 5 The reduction gear 50 will be described. Figure 4For convenience, the structure of the housing shown in FIG. Figure 3 The structure shown is simplified. The reduction gear 50 amplifies the input torque from the shaft 32 and outputs it to the drive wheel 12. In the present embodiment, in order to suppress the increase in the size of the electric drive device 20 in the vehicle width direction, the reduction gear 50 is a structure that is long in the vehicle length direction. The reduction gear 50 includes a housing 60 connected to the motor housing 34.

[0043] The housing 60 is in a generally rectangular parallelepiped shape with the direction perpendicular to the input shaft 70b and the output shaft 72b as the long side direction. The housing 60 has a generally rectangular bottom plate portion 66, a first long side wall portion 67a and a second long side wall portion 67b extending in a vertical direction from the long side of the bottom plate portion 66, a first short side wall portion 68a and a second short side wall portion 68b extending in a vertical direction from the short side of the bottom plate portion 66, and a top plate portion 69. The housing 60 is composed of a first housing component 61, a second housing component 62, and a third housing component 63. The output shaft 72b extends from an output side opening portion formed in the first long side wall portion 67a in the housing 60 to the outside of the housing 60. In addition, the input shaft 70b extends toward an opening portion 63a (equivalent to an “input side opening portion”) formed in the second long side wall portion 67b in the housing 60. In addition, Figure 5 FIG. 2 is a diagram showing the internal structure of the reduction gear 50 in a state where the second housing member 62 and the third housing member 63 are removed. Figure 5 For the sake of convenience, some structures are omitted from the illustration.

[0044] A plurality of spur gears constituting a speed reduction (speed change) mechanism are accommodated in the first space 64 surrounded by the first housing member 61 and the second housing member 62. Specifically, in the first space 64, the input side gear 70a, the intermediate gear 71a, and the output side gear 72a are arranged and accommodated along the long side direction of the housing 60. The input side gear 70a is provided with an input shaft 70b, the intermediate gear 71a is provided with an intermediate shaft 71b, and the output side gear 72a is provided with an output shaft 72b. The input shaft 70b, the intermediate shaft 71b, and the output shaft 72b extend in the same direction as the direction in which the shaft 32 extends. In the present embodiment, the rotation center axes of the input shaft 70b, the intermediate shaft 71b, the output shaft 72b, and the shaft 32 are located on the same plane.

[0045] An opening 63a is formed in the third housing member 63. The shaft 32 is inserted through the opening 63a. The first end of the shaft 32 is fixed to the first end of the input shaft 70b by a joint or the like. The second end of the input shaft 70b is rotatably supported by a first bearing 70c (rolling bearing) provided on the first longitudinal wall portion 67a.

[0046] The intermediate shaft 71b of the intermediate gear 71a meshing with the input side gear 70a is rotatably supported by the second bearing 71c (rolling bearing) provided on the first long-side wall portion 67a and the second long-side wall portion 67b. The output shaft 72b of the output side gear 72a meshing with the intermediate gear 71a is rotatably supported by the third bearing 72c (rolling bearing) provided on the first long-side wall portion 67a and the second long-side wall portion 67b. The output shaft 72b extends to the outside of the housing 60 via the output side opening portion provided with the third bearing 72c in the first long-side wall portion 67a. The drive wheel 12 is connected to the end of the output shaft 72b.

[0047] The diameter of the intermediate gear 71a is larger than the diameter of the input side gear 70a, and the diameter of the output side gear 72a is larger than the diameter of the intermediate gear 71a. That is, the diameters of the gears 70a, 71a, and 72a accommodated in the first space 64 increase from the side of the input shaft 70b toward the side of the output shaft 72b in the long side direction of the housing 60. As a result, the rotation speed of the output side gear 72a is reduced relative to the input side gear 70a, and the torque transmitted from the motor 30 to the input shaft 70b can be amplified and transmitted to the output shaft 72b.

[0048] Back to Figure 1 and Figure 2 As described above, each electric drive device 20 is arranged so that the long side direction of the housing 60 constituting the reduction gear 50 faces the vehicle length direction. In addition, each electric drive device 20 arranged in the vehicle width direction is arranged so that each output shaft 72b is arranged in the vehicle width direction.

[0049] like Figure 2 As shown, the upper part of the housing 60 of each electric drive device 20 and the lower part of the vehicle body 11 are connected via a steering mechanism 13. The steering mechanism 13 supports the electric drive device 20 so as to be rotatable relative to the vehicle body 11 around an axis orthogonal to the mounting surface 11a. Thus, the driving wheel 12 can be steered. The steering of the steering mechanism 13 is performed by, for example, a host ECU.

[0050] In addition, Figure 1 In the example shown, the motor 30 of the electric drive device 20 (equivalent to the "right device") corresponding to the right front wheel 12FR and the motor 30 of the electric drive device 20 (equivalent to the "left device") corresponding to the left front wheel 12FL are opposite in the vehicle length direction. In addition, the motor 30 of the electric drive device 20 (equivalent to the "right device") corresponding to the right rear wheel 12RR and the motor 30 of the electric drive device 20 (equivalent to the "left device") corresponding to the left rear wheel 12RL are opposite in the vehicle length direction. As a result, the dimension of the unmanned guided vehicle 10 in the vehicle width direction is reduced. In addition, each electric drive device 20 is configured in a manner that the top plate portion 69 is upward.

[0051] Each electric drive device 20 has a brake mechanism 80 for braking the drive wheel 12. Figures 4 to 8 The brake mechanism 80 will be described. Figure 6 and Figure 7 2 is a diagram showing the internal structure of the reduction gear 50 in a state where the third case member 63 is removed. Figure 6 and Figure 7 For the sake of convenience, some structures are omitted from the illustration.

[0052] The brake mechanism 80 of this embodiment applies a braking torque only to the input shaft 70b of the input shaft 70b and the output shaft 72b. The torque of the output shaft 72b is greater than the torque of the input shaft 70b. Therefore, the brake mechanism that applies a braking torque to the output shaft 72b tends to be large-scale. In contrast, according to the brake mechanism 80 of this embodiment, miniaturization can be achieved.

[0053] The brake mechanism 80 is a drum brake mechanism, and has a brake drum 81 (equivalent to a "rotating portion") provided on the input shaft 70b. The brake drum 81 is accommodated in the second space 65 surrounded by the second housing member 62 and the third housing member 63, and rotates integrally with the input shaft 70b. By accommodating the brake mechanism 80 in the housing 60, it is possible to suppress the size increase of the reduction gear 50.

[0054] A fixing portion 73 for fixing the brake drum 81 is provided on the input shaft 70b, which is closer to the motor 30 than the input side gear 70a. The brake drum 81 includes a circular plate portion 81a and a sliding portion 81b fixed to the fixing portion 73 by fastening members such as bolts. The sliding portion 81b is annular and extends from the peripheral edge of the circular plate portion 81a toward one side of the input side gear 70a in the direction in which the input shaft 70b extends. The brake drum 81 rotates integrally with the input shaft 70b. In addition, Figure 6 and Figure 7 This is a diagram showing a state in which the brake drum 81 is removed.

[0055] like Figure 4 , Figure 6 and Figure 7 As shown in FIG. 1 , the brake mechanism 80 includes a first brake pad 82 and a second brake pad 83. The first brake pad 82 is opposed to the inner peripheral surface of the sliding portion 81b of the brake drum 81 and has an arc shape extending along the inner peripheral surface. The second brake pad 83 is opposed to the inner peripheral surface of the sliding portion 81b on the opposite side of the surface of the first brake pad 82 opposed to the input shaft 70b and has an arc shape extending along the inner peripheral surface.

[0056] The brake mechanism 80 includes an anchor portion 84 and a return spring 85 as a biasing portion (see Figure 8 ).in addition, Figure 8Observed from the back Figure 7 The anchor portion 84 is a member that supports the first end portion of each of the first brake pad 82 and the second brake pad 83 so as to be rotatable relative to the housing 60 about the direction in which the input shaft 70b extends. The anchor portion 84 is fixed to the housing 60 (for example, the first longitudinal wall portion 67a of the first housing member 61).

[0057] The return spring 85 is mounted on each brake pad 82, 83, and is a component that applies elastic force to the first brake pad 82 and the second brake pad 83 in the direction in which the second ends of the first brake pad 82 and the second brake pad 83 approach each other. In addition, a rotation spring may be mounted on each brake pad 82, 83 instead of the return spring 85. The rotation spring is provided in a manner that rotates around the anchor bolt portion 84. In this case, the rotation spring also applies elastic force to the first brake pad 82 and the second brake pad 83 in the direction in which the second ends of the first brake pad 82 and the second brake pad 83 approach each other.

[0058] Each brake pad 82 , 83 is configured such that a first end portion of each brake pad 82 , 83 faces a second end portion of each brake pad 82 , 83 across the input shaft 70 b .

[0059] The first brake pad 82 has an arcuate first bushing 82a (equivalent to the "pressing portion") at the arcuate portion facing the sliding portion 81b. The second brake pad 83 has an arcuate second bushing 83a (equivalent to the "pressing portion") at the arcuate portion facing the sliding portion 81b.

[0060] The brake pads 82 and 83 are arranged so that the first end of each brake pad 82 and 83 is on the bottom plate portion 66 side and the second end of each brake pad 82 and 83 is on the top plate portion 69 side. In addition, the brake pads 82 and 83 are arranged so that the second end of each brake pad 82 and 83 is located on the side of the output shaft 72b relative to the input shaft 70b in the long side direction of the housing 60.

[0061] The brake mechanism 80 has a function for making each bushing 82a, 83a Figure 6 status or Figure 7 The position changing unit in any state of Figure 6 The state is a state in which the first brake pad 82 and the second brake pad 83 are pushed apart in a direction in which the second end of the first brake pad 82 is separated from the second end of the second brake pad 82 and abut against the inner peripheral surface of the sliding portion 81b, Figure 7 The state is a state in which the second end of the first brake pad 82 and the second end of the second brake pad 83 are close to each other and separated from the inner peripheral surface of the sliding portion 81b. Figures 4 to 11As shown, the position changing unit includes a cam portion 90, a solenoid coil 100, a spring 110, a seat portion 111, and a rod portion 120. Fig. 9 is with Figure 6 The corresponding figure, Fig.10 is with Figure 7 The corresponding figure.

[0062] The cross-sectional shape of the cam portion 90 is an ellipse having a long diameter direction and a short diameter direction. Fig.11 As shown, the cam portion 90 is fixed to a first end portion of a support portion 121 constituting the rod portion 120. The support portion 121 extends in the direction in which the input shaft 70b extends. The second end portion of the support portion 121 is supported by the first long-side direction wall portion 67a in a manner that allows rotation around the direction in which the input shaft 70b extends. Thus, the cam portion 90 is supported by the housing 60 in a manner that allows rotation around the direction in which the input shaft 70b extends.

[0063] The solenoid coil 100 is a linear actuator having a coil portion 101 (equivalent to a "main body") and a movable iron core 102 (equivalent to a "movable portion"), wherein the coil portion 101 includes a fixed iron core and a coil wound around the fixed iron core, and the movable iron core 102 can move in a linear direction relative to the coil portion 101. Figure 4 and Fig.11 As shown, the solenoid coil 100 is disposed on the second short-side wall portion 68b side relative to the input side gear 70a in the housing 60. Also, the solenoid coil 100 is disposed on the first long-side wall portion 67a side relative to the brake drum 81 in the housing 60.

[0064] The coil portion 101 of the solenoid coil 100 is fixed to the housing 60 (for example, at least one of the bottom plate portion 66 and the second short-side direction wall portion 68b). By energizing the coil portion 101, the movable iron core 102 can move in the long-side direction of the housing 60 and in the direction orthogonal to the input shaft 70b. The energizing operation of the coil portion 101 is performed, for example, by the motor ECU or the upper ECU. When the coil portion 101 is energized, the movable iron core 102 is attracted by the magnetic force of the coil portion 101, and the movable iron core 102 moves in a direction close to the coil portion 101.

[0065] In addition, the solenoid coil 100 includes a wiring 103 for energizing the coil portion 101. The wiring 103 is used to supply power from the power storage unit to the coil portion 101. The wiring 103 is connected via a through hole 130 and a sealing portion 131 (see FIG. 1 ) formed in the second short-side wall portion 68b of the housing 60. Figure 3 ) is pulled out of the housing 60. The wiring 103 is arranged in a space on the second short-side wall portion 68b side relative to the input-side gear 70a in the housing 60. Therefore, the wiring 103 is less likely to be caught in rotating parts such as the input-side gear 70a.

[0066] The spring 110 (eg, a compression spring) extends in the operating direction of the movable core 102 and is arranged in parallel with the solenoid coil 100 in the direction in which the input shaft 70b extends. The base end of the spring 110 is attached to a seat 111 fixed to the bottom plate 66.

[0067] The rod 120 includes a main connection portion 122 extending from the support portion 121 in the long side direction of the housing 60 and a sub-connection portion 123 branching from the middle portion of the main connection portion 122. In the present embodiment, the support portion 121, the main connection portion 122 and the sub-connection portion 123 are integrally formed, and the rod 120 is formed as one component. The top end portion of the main connection portion 122 is connected to the top end portion of the movable iron core 102. In the present embodiment, the connection portion between the main connection portion 122 and the movable iron core 102 allows rotation around the direction in which the input shaft 70b extends.

[0068] The auxiliary connection portion 123 is provided with a seat portion 124. The front end portion of the spring 110 is mounted on the seat portion 124.

[0069] Next, the operation of the brake mechanism 80 will be described. Hereinafter, the motor ECU or the host ECU will be simply referred to as ECU.

[0070] When the ECU determines that a braking instruction has been issued, it stops the power supply from the power storage unit to the coil unit 101. As a result, the attraction force no longer acts on the movable iron core 102, and the movable iron core 102 moves away from the coil unit 101 due to the restoring force of the spring 110. As a result, the top position of the movable iron core 102 is located at Fig. 9 The first position is shown.

[0071] The top end position of the movable iron core 102 approaches the first position, and the cam portion 90 rotates in the first direction via the rod portion 120. When the top end position of the movable iron core 102 is at the first position, the first end of the cam portion 90 in the long-diameter direction abuts against the second end of the first brake pad 82, and the second end of the cam portion 90 in the long-diameter direction abuts against the second end of the second brake pad 83. As a result, the first brake pad 82 and the second brake pad 83 are pushed apart, and each bushing 82a, 83a abuts against the inner peripheral surface of the sliding portion 81b constituting the brake drum 81. As a result, a braking torque is applied to the input shaft 70b.

[0072] The spring 110 applies elastic force to the rod 120. Here, the spring 110 is arranged side by side with the solenoid coil 100 in the direction in which the input shaft 70b extends. Therefore, the distance between the cam portion 90 and the top end of the spring 110 can be increased, and the rotation amount of the cam portion 90 relative to the spring 110 side end of the rod 120 by a predetermined displacement amount in the up-down direction can be increased, so that each brake pad 82, 83 can be reliably pushed open. In addition, the distance between the cam portion 90 and the top end of the spring 110 can be increased, and the torque around the main connecting portion 122 can be increased. Furthermore, according to Fig. 9 and Fig.10 The structure in which the spring 110 is arranged in the vacant space shown can increase the free length and diameter of the spring 110. According to the above structure, the braking torque can be increased, and for example, the parking state of the automated guided vehicle 10 can be reliably maintained.

[0073] Furthermore, by arranging the spring 110 in parallel with the solenoid coil 100 in the direction in which the input shaft 70 b extends, the vertical dimension of the solenoid coil 100 can be reduced compared to a structure in which the spring is provided on the movable core 102 . As a result, the vertical dimension of the automated guided vehicle 10 can be reduced.

[0074] In this embodiment, Fig. 9 In the state shown, the length of the spring 110 is shorter than the free length, and the spring 110 is in a compressed state. Therefore, each bushing 82a, 83a can be reliably pressed against the inner peripheral surface of the sliding portion 81b.

[0075] In the present embodiment, there is an empty space on the side of the top plate portion 69 of the input side gear 70a having the smallest diameter among the spur gears constituting the speed reduction mechanism. In order to effectively utilize the space, the support portion 121 of the rod portion 120 is arranged in the space. As a result, the distance between the cam portion 90 and the top end portion of the spring 110 can be further increased, and the moment around the main connection portion 122 can be further increased. As a result, the braking torque can be further increased without increasing the size of the speed reduction device 50 in the vertical direction.

[0076] When the coil unit 101 is not energized, a braking torque is applied to the input shaft 70 b . Therefore, when the unmanned guided vehicle 10 is not in use, such as when the unmanned guided vehicle 10 is being stored, the unmanned guided vehicle 10 can be prevented from starting to move.

[0077] On the other hand, when the ECU determines that there is no braking instruction, the coil unit 101 is energized from the power storage unit. As a result, the attraction acts on the movable iron core 102, and the movable iron core 102 moves in a manner that the movable iron core 102 approaches the coil unit 101 while overcoming the restoring force of the spring 110. As a result, the top position of the movable iron core 102 is located at Fig.10 The second position is shown.

[0078] The top position of the movable iron core 102 approaches the second position, and the cam portion 90 rotates in the second direction opposite to the first direction via the rod portion 120. When the top position of the movable iron core 102 is the second position, the end of the cam portion 90 in the short-diameter direction is in a state facing the second end side of each brake pad 82, 83. Due to the restoring force of the return spring 85, the first end of the cam portion 90 in the short-diameter direction abuts against the second end of the first brake pad 82, and the second end of the cam portion 90 in the short-diameter direction abuts against the second end of the second brake pad 83. As a result, the second end of the first brake pad 82 and the second end of the second brake pad 83 approach each other, and each bushing 82a, 83a is in a state of being separated from the inner peripheral surface of the sliding portion 81b. As a result, the braking torque is not applied to the input shaft 70b.

[0079] In this embodiment, the solenoid coil 100 and the spring 110 and other structures required for the operation of the brake pads 82 and 83 are not arranged between the brake pads 82 and 83, but are arranged in the adjacent space between the brake pads 82 and 83. Thus, the outer diameter of the brake drum 81 can be reduced, and the reduction gear 50 can be miniaturized.

[0080] In this embodiment, the vehicle body 11 is long in the vehicle length direction and short in the vehicle width direction. Therefore, it is desirable to minimize the dimension of the reduction gear 50 in the vehicle length direction. Therefore, a mechanism with spur gears is used as a reduction mechanism, and a solenoid coil 100 and a spring 110 are arranged in the housing 60 in a space adjacent to the input shaft 70b in the vehicle length direction. As a result, the dimension of the reduction gear 50 in the vehicle width direction can be reduced.

[0081] <Other Implementation Methods>

[0082] In addition, the above-mentioned embodiment may be implemented by being modified as follows.

[0083] In the speed reduction mechanism, a plurality of intermediate gears may be arranged in a row along the long side direction of the housing 60. In this case, the diameter of each intermediate gear may increase, for example, from the input shaft 70b side toward the output shaft 72b side in the long side direction of the housing 60. In addition, the intermediate gear 71a may not be provided in the speed reduction mechanism, and the input side gear 70a and the output side gear 72a may be directly meshed.

[0084] The linear actuator is not limited to the solenoid coil, and may include, for example, a ball screw (corresponding to the "movable part") and a motor (corresponding to the "main body") for moving the ball screw in a linear direction.

[0085] The support portion 121 that rotatably supports the cam portion 90 may be formed of a member different from the lever portion 120 .

[0086] The braking mechanism is not limited to a drum brake mechanism, and may be, for example, a disc brake mechanism. In this case, the braking mechanism may include a disc rotor (equivalent to a "rotating portion"), a brake pad (equivalent to a "pushing portion"), and a brake caliper (equivalent to a "position changing portion"). The disc rotor is provided on the input shaft and rotates integrally with the input shaft. The brake pad applies a braking torque to the input shaft by contacting the disc rotor, and stops applying the braking torque to the input shaft by separating from the disc rotor. The brake caliper is operated by powering on, so that the brake pad is in contact with the disc rotor or separated from the disc rotor.

[0087] The braking mechanism is not limited to a structure that applies braking torque only to the input shaft of the input shaft and the output shaft, and may apply braking torque only to the output shaft, or apply braking torque to both the input shaft and the output shaft.

[0088] The speed reduction mechanism is not limited to a mechanism including spur gears, and may be, for example, a planetary gear mechanism or a cycloid gear mechanism in which the rotation center axes of the input shaft and the output shaft are the same.

[0089] The speed change device provided in the electric drive device is not limited to a speed reduction device, and may be a speed increase device that increases the rotation speed of the input shaft and transmits the speed to the output shaft.

[0090] The electric motor is not limited to an inner rotor type structure, and may be an outer rotor type structure. In addition, the electric motor is not limited to a radial gap type structure, and may be an axial gap type structure.

[0091] As an unmanned guided vehicle, for example Fig.12 and Fig.13 In the unmanned guided vehicle 10a shown in FIG. 1 , the electric drive devices 20 arranged in the vehicle width direction are arranged so that the electric motors 30 are opposite to each other in the vehicle width direction and the output shafts 72b are arranged in the vehicle width direction. Fig.12 and Fig.13 In the example shown, the electric drive device 20 for rotating the right front wheel 12FR and the left rear wheel 12RL is arranged with the top plate portion 69 facing upward. On the other hand, the electric drive device 20 for rotating the left front wheel 12FL and the right rear wheel 12RR is arranged with the bottom plate portion 66 facing upward.

[0092] The unmanned guided vehicle is not limited to a four-wheel vehicle, and may be, for example, a six-wheel vehicle having three sets of driving wheels arranged in the vehicle width direction, or a two-wheel vehicle having one set. In addition, the unmanned guided vehicle is not limited to a structure in which all wheels are driving wheels, and may be a structure in which some wheels are driven wheels.

[0093] The unmanned guided vehicle used in the factory is not limited to the AGV, and may be, for example, an autonomous mobile robot (AMR: Autonomous Mobile Robot).

[0094] In addition, the small mobility is not limited to the unmanned guided vehicle, and may be, for example, a small electric vehicle such as an electric wheelchair or an assistive vehicle. The small electric vehicle is, for example, a vehicle with a travel speed of 10 km / h or less.

[0095] The control unit and method described in the present disclosure may also be implemented by a special-purpose computer, which is provided by constituting a processor and a memory, and the processor and the memory are programmed to perform one or more functions embodied by a computer program. Alternatively, the control device and method described in the present disclosure may also be implemented by a special-purpose computer provided by constituting a processor by one or more special-purpose hardware logic circuits. Alternatively, the control device and method described in the present disclosure may also be implemented by one or more special-purpose computers, which are composed of a combination of a processor and a memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-volatile tangible storage medium as an instruction executed by a computer.

[0096] The following describes technical features extracted from each of the above-mentioned embodiments.

[0097] [Structure 1]

[0098] A speed change device (50) comprising:

[0099] Input shaft (70b);

[0100] An output shaft (72b) extending in the direction in which the input shaft extends;

[0101] a speed change mechanism (70a, 71a, 72a) which changes the rotation speed of the input shaft and transmits it to the output shaft;

[0102] a housing (60) accommodating the input shaft, the output shaft and the speed change mechanism; and

[0103] a brake mechanism (80) that applies a braking torque to at least one of the input shaft and the output shaft,

[0104] The brake mechanism is accommodated in the housing.

[0105] [Structure 2]

[0106] According to the speed change device described in structure 1,

[0107] The speed change mechanism is a speed reduction mechanism that reduces the rotation speed of the input shaft and transmits the speed to the output shaft.

[0108] The brake mechanism applies a braking torque to the input shaft of the input shaft and the output shaft.

[0109] [Structure 3]

[0110] According to the speed change device described in structure 2,

[0111] The brake mechanism comprises:

[0112] A rotating part (81), which is arranged on the input shaft and rotates integrally with the input shaft;

[0113] a pressing portion (82a, 83a) that applies a braking torque to the input shaft by coming into contact with the rotating portion and stops applying the braking torque to the input shaft by moving away from the rotating portion; and

[0114] a position changing unit (90, 100, 110, 111, 120) which, by powering on, causes the pressing unit to be in either a state of contact with the rotating unit or a state of separation from the rotating unit,

[0115] The position changing portion is accommodated in the housing.

[0116] [Structure 4]

[0117] According to the speed change device described in structure 3,

[0118] The rotating part is a brake drum,

[0119] The brake mechanism comprises:

[0120] a first brake pad (82), the first brake pad being opposite to the inner peripheral surface of the brake drum and comprising an arc-shaped portion extending along the inner peripheral surface;

[0121] a second brake pad (83) which is opposed to an inner peripheral surface of the brake drum on the opposite side of the input shaft from the surface opposed to the first brake pad and includes an arc-shaped portion extending along the inner peripheral surface;

[0122] an anchor portion (84) that supports first ends of the first brake pad and the second brake pad so as to be rotatable relative to the housing about a direction in which the input shaft extends; and

[0123] a force applying portion (85) for applying elastic force to the first brake pad and the second brake pad in a direction in which the second ends of the first brake pad and the second brake pad approach each other,

[0124] The pressing portion is a bushing (82a, 83a) provided on the arc-shaped portion of each of the first brake pad and the second brake pad.

[0125] The position changing portion causes the bushing to be in either of the following two states: a state in which the first brake pad and the second brake pad are pushed apart in a direction in which the second end of the first brake pad and the second end of the second brake pad are separated and abut against the inner circumferential surface of the brake drum; and a state in which the second end of the first brake pad and the second end of the second brake pad are brought close to each other and separated from the inner circumferential surface of the brake drum.

[0126] [Structure 5]

[0127] According to the speed change device described in structure 4,

[0128] The position changing unit comprises:

[0129] A cam portion (90), the cam portion having a major diameter direction and a minor diameter direction;

[0130] a support portion (121) that supports the cam portion so as to be rotatable about a direction in which the input shaft extends;

[0131] a rod portion (120); and

[0132] An actuator (100) includes a main body (101) and a movable part (101) capable of moving in a linear direction relative to the main body.

[0133] The cam portion and the movable portion are connected via the rod portion.

[0134] In a first state in which the first end of the cam portion in the long-diameter direction abuts against the second end of the first brake pad and the second end of the cam portion in the long-diameter direction abuts against the second end of the second brake pad, the first brake pad and the second brake pad are pushed apart so that the bushing abuts against the inner peripheral surface of the brake drum.

[0135] In a second state in which the first end of the cam portion in the short-diameter direction abuts against the second end of the first brake pad and the second end of the cam portion in the short-diameter direction abuts against the second end of the second brake pad, the second end of the first brake pad and the second end of the second brake pad approach each other so that the bushing is separated from the inner peripheral surface of the brake drum.

[0136] The position changing portion is configured such that when the top end position of the movable portion is located at a first position, the action state of the cam portion becomes the first state; when the top end position of the movable portion is located at a second position closer to the main body portion than the first position, the action state of the cam portion becomes the second state.

[0137] [Structure 6]

[0138] According to the speed change device described in structure 5,

[0139] The housing has a shape with its long side being in a direction perpendicular to the input shaft and the output shaft.

[0140] The input shaft and the output shaft are arranged in parallel along the long side direction of the housing.

[0141] The speed reduction mechanism comprises:

[0142] an input-side spur gear (70a) disposed on the input shaft; and

[0143] an output-side spur gear (72a), which is disposed on the output shaft and has a larger diameter than the input-side spur gear,

[0144] The actuator is provided in the housing on a side opposite to a side of the output shaft with respect to the input shaft.

[0145] The movable portion is movable along the longitudinal direction of the housing and in a direction perpendicular to the input shaft.

[0146] The cam portion and the support portion are arranged at positions farther from the input shaft than the input-side spur gear in a direction from the input shaft toward the cam portion.

[0147] [Structure 7]

[0148] According to the speed change device described in structure 5 or 6,

[0149] The actuator is a solenoid coil having a coil portion as the main body portion and a movable iron core as the movable portion.

[0150] The position changing part includes a spring (110) for applying elastic force to the rod part so that the position of the movable part becomes the first position.

[0151] The position changing unit is configured such that the position of the movable unit is set to the second position by energizing the main body, and the position of the movable unit is set to the first position by stopping energizing the main body.

[0152] [Structure 8]

[0153] According to the speed change device described in structure 7,

[0154] The movable portion is movable along the longitudinal direction of the housing and in a direction orthogonal to the input shaft.

[0155] The spring extends in an operating direction of the movable portion and is arranged in parallel with the solenoid coil in a direction in which the input shaft extends.

[0156] [Structure 9]

[0157] An electric drive device (20) mounted on a vehicle (10, 10a), comprising:

[0158] The speed change device according to any one of structures 5 to 8; and

[0159] An electric motor (30) applies a rotational torque to the input shaft of the speed change device.

[0160] [Structure 10]

[0161] An in-vehicle system comprising a plurality of electric drive devices according to structure 9,

[0162] In each of the electric drive devices, the output shaft extends from an output-side opening formed in the housing at one side of a first end portion in a longitudinal direction of the housing to the outside of the housing.

[0163] In each of the electric drive devices, the input shaft extends toward an input-side opening formed in the housing at one side of the second end portion in the longitudinal direction of the housing.

[0164] In each of the electric drive devices, the input side opening is formed on the opposite side to one side of the output side opening with respect to an axis extending in the longitudinal direction of the housing.

[0165] In each of the electric drive devices, the electric motor is mounted at a position of the input side opening portion in the housing.

[0166] In each of the electric drive devices, the output shaft is connected to a drive wheel (12) of the vehicle.

[0167] A right device of the electric drive device for rotating the right driving wheel of the vehicle and a left device of the electric drive device for rotating the left driving wheel of the vehicle are arranged in a row in a vehicle width direction on a body (11) of the vehicle.

[0168] The right device and the left device are arranged so that the longer sides of the housings of the right device and the left device, which are arranged in line in the vehicle width direction, face the vehicle length direction.

[0169] [Structure 11]

[0170] According to the vehicle-mounted system of Configuration 10, a dimension of the vehicle body in a vehicle width direction is smaller than a dimension of the vehicle body in a vehicle length direction.

[0171] [Structure 12]

[0172] According to the vehicle-mounted system of structure 9 or 10, the vehicle is an unmanned guided vehicle used in a work site.

[0173] The present disclosure is described according to the embodiments. However, it should be understood that the present disclosure is not limited to the embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, although the present disclosure discloses various combinations and methods, other combinations and methods including only one element among these, or including elements above these or elements below these are all within the scope and thought of the present disclosure.

Claims

1. A speed change device (50), characterized in that: have: Input shaft (70b); An output shaft (72b) extending in the direction in which the input shaft extends; a speed change mechanism (70a, 71a, 72a) which changes the rotation speed of the input shaft and transmits it to the output shaft; a housing (60) for accommodating the input shaft, the output shaft and the speed change mechanism; as well as a brake mechanism (80) that applies a braking torque to at least one of the input shaft and the output shaft, The brake mechanism is accommodated in the housing.

2. The speed change device according to claim 1, characterized in that: The speed change mechanism is a speed reduction mechanism that reduces the rotation speed of the input shaft and transmits the speed to the output shaft. The brake mechanism applies a braking torque to the input shaft of the input shaft and the output shaft.

3. The speed change device according to claim 2, characterized in that: The brake mechanism comprises: A rotating part (81), which is arranged on the input shaft and rotates integrally with the input shaft; a pressing portion (82a, 83a) that applies a braking torque to the input shaft by coming into contact with the rotating portion and stops applying the braking torque to the input shaft by moving away from the rotating portion; and a position changing unit (90, 100, 110, 111, 120) which, by powering on, causes the pressing unit to be in either a state of contact with the rotating unit or a state of separation from the rotating unit, The position changing portion is accommodated in the housing.

4. The speed change device according to claim 3, characterized in that: The rotating part is a brake drum, The brake mechanism comprises: a first brake pad (82), the first brake pad being opposite to the inner peripheral surface of the brake drum and comprising an arc-shaped portion extending along the inner peripheral surface; a second brake pad (83) which is opposed to an inner peripheral surface of the brake drum on the opposite side of the input shaft from the surface opposed to the first brake pad and includes an arc-shaped portion extending along the inner peripheral surface; an anchor portion (84) that supports first ends of the first brake pad and the second brake pad so as to be rotatable relative to the housing about a direction in which the input shaft extends; as well as a force applying portion (85) for applying elastic force to the first brake pad and the second brake pad in a direction in which the second ends of the first brake pad and the second brake pad approach each other, The pressing portion is a bushing (82a, 83a) provided on the arc-shaped portion of each of the first brake pad and the second brake pad. The position changing portion causes the bushing to be in either of the following two states: a state in which the first brake pad and the second brake pad are pushed apart in a direction in which the second end of the first brake pad and the second end of the second brake pad are separated and abut against the inner circumferential surface of the brake drum; and a state in which the second end of the first brake pad and the second end of the second brake pad are brought close to each other and separated from the inner circumferential surface of the brake drum.

5. The speed change device according to claim 4, characterized in that: The position changing unit comprises: A cam portion (90), the cam portion having a major diameter direction and a minor diameter direction; a support portion (121) that supports the cam portion so as to be rotatable about a direction in which the input shaft extends; A rod portion (120); as well as An actuator (100) includes a main body (101) and a movable part (101) capable of moving in a linear direction relative to the main body. The cam portion and the movable portion are connected via the rod portion. In a first state in which the first end of the cam portion in the long-diameter direction abuts against the second end of the first brake pad and the second end of the cam portion in the long-diameter direction abuts against the second end of the second brake pad, the first brake pad and the second brake pad are pushed apart so that the bushing abuts against the inner peripheral surface of the brake drum. In a second state in which the first end of the cam portion in the short-diameter direction abuts against the second end of the first brake pad and the second end of the cam portion in the short-diameter direction abuts against the second end of the second brake pad, the second end of the first brake pad and the second end of the second brake pad approach each other so that the bushing is separated from the inner peripheral surface of the brake drum. The position changing portion is configured such that when the top end position of the movable portion is located at a first position, the action state of the cam portion becomes the first state; when the top end position of the movable portion is located at a second position closer to the main body portion than the first position, the action state of the cam portion becomes the second state.

6. The speed change device according to claim 5, characterized in that: The housing has a shape with its long side being in a direction perpendicular to the input shaft and the output shaft. The input shaft and the output shaft are arranged in parallel along the long side direction of the housing. The speed reduction mechanism comprises: An input-side spur gear (70a), the input-side spur gear being arranged on the input shaft; as well as an output-side spur gear (72a), which is disposed on the output shaft and has a larger diameter than the input-side spur gear, The actuator is provided in the housing on a side opposite to a side of the output shaft with respect to the input shaft. The movable portion is movable along the longitudinal direction of the housing and in a direction perpendicular to the input shaft. The cam portion and the support portion are arranged at positions farther from the input shaft than the input-side spur gear in a direction from the input shaft toward the cam portion.

7. The speed change device according to claim 5 or 6, characterized in that: The actuator is a solenoid coil having a coil portion as the main body portion and a movable iron core as the movable portion. The position changing part includes a spring (110) for applying elastic force to the rod part so that the position of the movable part becomes the first position. The position changing unit is configured such that the position of the movable unit is set to the second position by energizing the main body, and the position of the movable unit is set to the first position by stopping energizing the main body.

8. The speed change device according to claim 7, characterized in that: The movable portion is movable along the longitudinal direction of the housing and in a direction orthogonal to the input shaft. The spring extends in an operating direction of the movable portion and is arranged in parallel with the solenoid coil in a direction in which the input shaft extends.

9. An electric drive device (20) mounted on a vehicle (10, 10a), characterized in that: have: The speed change device according to claim 5 or 6; and An electric motor (30) applies a rotational torque to the input shaft of the speed change device.

10. An in-vehicle system comprising a plurality of electric drive devices according to claim 9, characterized in that: In each of the electric drive devices, the output shaft extends from an output-side opening formed in the housing at one side of a first end portion in a longitudinal direction of the housing to the outside of the housing. In each of the electric drive devices, the input shaft extends toward an input-side opening formed in the housing at one side of the second end portion in the longitudinal direction of the housing. In each of the electric drive devices, the input side opening is formed on the opposite side to one side of the output side opening with respect to an axis extending in the longitudinal direction of the housing. In each of the electric drive devices, the electric motor is mounted at a position of the input side opening portion in the housing. In each of the electric drive devices, the output shaft is connected to a drive wheel (12) of the vehicle. A right device of the electric drive device for rotating the right driving wheel of the vehicle and a left device of the electric drive device for rotating the left driving wheel of the vehicle are arranged in a row in a vehicle width direction on a body (11) of the vehicle. The right device and the left device are arranged so that the longer sides of the housings of the right device and the left device, which are arranged in line in the vehicle width direction, face the vehicle length direction.

11. The vehicle-mounted system according to claim 10, characterized in that: A dimension of the vehicle body in a vehicle width direction is smaller than a dimension of the vehicle body in a vehicle length direction.

12. The vehicle-mounted system according to claim 10, characterized in that: The vehicle is an unmanned guided vehicle used in a work site.

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