Master machine

Abstract

A master machine 100 comprises: a motor 11; a first transmission 21A that varies the speed of rotation of the motor 11; and a second transmission 21B that varies the speed of rotation of the motor 11 in parallel with the first transmission 21A. The first transmission 21A and the second transmission 21B of the master machine 100 are continuously variable transmissions that have variable transmission ratios including a transmission ratio of zero. The master machine 100 may also include: a first arm 91 that is driven by output rotation of the first transmission 21A; a second arm 92 that is connected to the distal end side of the first arm 91 and is driven by output rotation of the second transmission 21B; and a rotation transmitting mechanism 36 that is disposed between the motor 11 and the second transmission 21B.

Description

Parent machine

[0001] The present disclosure relates to a parent machine.

[0002] Robots having multiple drive sources and reducers are known. For example, Patent Document 1 describes an articulated robot having multiple joints. The robot described in Patent Document 1 includes a base, an arm unit, three joints, and an end effector. Each of the three joints has a reducer and a servomotor as a drive source. Each arm unit of this robot is driven to swing by the rotation of the servomotor of each joint.

[0003] Japanese Patent Application Laid-Open No. 2023-113542

[0004] In the articulated robot described in Patent Document 1, a prime mover such as a motor and a reducer are provided at each of a plurality of joints. The reducer has a fixed gear ratio, and the output rotation speed and rotation direction are controlled by the prime mover. In such an articulated robot, the number of prime movers increases in accordance with the number of joints, which poses a problem in that the consumption of raw materials related to the prime movers (such as copper and rare metals in the case of motors) increases in accordance with the number of prime movers.

[0005] The present disclosure has been made in view of such problems, and one of its objects is to provide a parent machine that can reduce the number of prime movers used and the amount of raw materials consumed.

[0006] In order to solve the above problems, a parent machine according to one aspect of the present disclosure includes a prime mover, a first transmission that changes the rotation speed of the prime mover, and a second transmission that changes the rotation speed of the prime mover in parallel with the first transmission. The first transmission and the second transmission are continuously variable transmissions with variable gear ratios, including a gear ratio of 0.

[0007] Any combination of the above components, or mutual substitution of the components or expressions of the present disclosure between methods, systems, etc., are also valid aspects of the present disclosure.

[0008] According to the present disclosure, it is possible to provide a parent machine that can reduce the number of prime movers used and the amount of raw material consumed.

[0009] FIG. 1 is a side view showing a parent machine of a first embodiment. FIG. 2 is a schematic view showing the configuration of the parent machine of FIG. 1. FIG. 3 is a schematic view showing the configuration of an articulated robot of a comparative example. FIG. 4 is a longitudinal sectional view showing the configuration of a speed change unit of the parent machine of FIG. 2. FIG. 5 is a schematic view showing a modified example of the parent machine of FIG. 1. FIG. 6 is a side view showing a parent machine of a second embodiment. FIG. 7 is a schematic view showing the configuration of the parent machine of FIG. 6. FIG. 8 is a schematic view showing the configuration of a self-propelled carriage of a comparative example. FIG. 9 is a schematic view showing a first modified example of the parent machine of FIG. 6. FIG. 10 is a schematic view showing a second modified example of the parent machine of FIG. 6.

[0010] The present disclosure will be described below based on preferred embodiments with reference to the drawings. In the embodiments and modified examples, identical or equivalent components and members are assigned the same reference numerals, and redundant description will be omitted where appropriate. The dimensions of the components in the drawings are enlarged or reduced as appropriate for ease of understanding. Some components that are not important for explaining the embodiments are omitted from the drawings. When describing identical or equivalent components, capital letters such as A, B, and C are added to the end of the reference numerals.

[0011] Furthermore, terms including ordinal numbers such as first and second are used to describe various components, but these terms are used only to distinguish one component from another and do not limit the components.

[0012] [First embodiment] A parent machine 100 according to a first embodiment of the present disclosure will be described with reference to Figures 1 to 5. Figure 1 is a side view of the parent machine 100. Figure 2 is a schematic diagram showing the configuration of the parent machine 100. Figure 3 is a schematic diagram showing the configuration of a multi-joint robot 600 of a comparative example. The parent machine 100 of this embodiment is a multi-joint robot, and in particular a multi-joint SCARA robot whose arms move horizontally.

[0013] The parent machine 100 of this embodiment has a stationary link 90, a first arm 91 connected to the tip end of the stationary link 90 via a first joint 95, a second arm 92 connected to the tip end of the first arm 91 via a second joint 96, and an up / down unit 93 connected to the tip end of the second arm 92 via a third joint 97. The tip end of the first arm 91 swings horizontally about a rotation axis L1 relative to the stationary link 90, and the tip end of the second arm 92 swings horizontally about a rotation axis L2 relative to the tip end of the first arm 91. The up / down unit 93 is a circular rod-shaped part that moves up and down along a rotation axis L3 relative to the second arm 92, and end effectors (not shown) with various functions are attached to the tip of the up / down unit 93.

[0014] First, a comparative example of an articulated robot 600 will be described with reference to FIG. 3. The articulated robot 600 was created for comparison purposes during the development process of the parent machine 100. As shown in FIG. 3, the articulated robot 600 differs from the parent machine 100 in that a first joint 95, a second joint 96, and a third joint 97 are each provided with a set of a motor 98 and a reducer 99, but the other configurations are similar. In other words, the articulated robot 600 has three sets of motors 98 and reducers 99. Each reducer 99 is configured to reduce the rotation input from the corresponding motor 98 and output it from an output shaft 94 to move a downstream arm, etc.

[0015] The motor shaft (not shown) of the motor 98 of the third joint 97 and the output shaft 94 of the reducer 99 are hollow shafts through which the vertical unit 93 passes vertically without contacting them. The vertical unit 93 is configured to move vertically by receiving rotation transmitted from the output shaft 94 of the reducer 99.

[0016] In the articulated robot 600, the speed reducer 99 has a fixed gear ratio, and the output rotation speed and rotation direction are controlled by the motor 98. The articulated robot 600 uses as many motors 98 as there are joints, so the number of motors 98 increases in accordance with the number of joints, and the consumption of motor raw materials such as copper and rare metals increases.

[0017] The parent machine 100 of this embodiment will be described based on the description of the comparative example. The inventor conceived of a configuration in which a single prime mover drives multiple joints in order to reduce raw material consumption. However, it was found that using a reducer with a fixed gear ratio makes it difficult to independently control multiple joints because the output rotation speed and rotation direction of the reducer are fixed to the rotation speed and rotation direction of the single prime mover. Therefore, the inventor devised a configuration in which joints 95, 96, and 97 are provided with a transmission unit 20 including a transmission 21 with a variable gear ratio in order to independently control multiple joints.

[0018] As shown in Figure 2, in the parent machine 100, a speed change unit 20A is provided at the first joint 95, a speed change unit 20B is provided at the second joint 96, and a speed change unit 20C is provided at the third joint 97. In the parent machine 100, the speed change unit 20A, the speed change unit 20B, and the speed change unit 20C drive each joint by changing the speed of rotation input from a single prime mover 11 provided at the stationary link 90. ​​In the parent machine 100, each joint does not have its own dedicated prime mover 11, so the number of prime movers 11 is reduced and the amount of raw material consumed by the prime movers 11 can be reduced.

[0019] The transmission unit 20 will be described with reference to FIG. 4 . FIG. 4 is a vertical cross-sectional view showing the configuration of the transmission unit 20. For convenience of explanation, the right side in the axial direction in FIG. 4 is referred to as the input side, and the opposite side is referred to as the non-input side. The transmission unit 20 includes a transmission 21 and a transmission actuator 15. The transmission 21 includes an input shaft 22, a speed change mechanism 24, a gear ratio change mechanism 23, and a variable speed transmission mechanism 27. The input shaft 22 receives rotation of a target for speed change from a front device 17. The front device 17 is the prime mover 11 or a front-stage variable speed transmission mechanism 27. In other words, the input shaft 22 may be configured to receive rotation from the prime mover 11 directly, or to receive rotation from the prime mover 11 via the front-stage variable speed transmission mechanism 27. Below, an example will be described in which the front device 17 is the prime mover 11, but this description also applies when the front device 17 is the variable speed transmission mechanism 27. The transmission unit 20 changes the speed of the rotation input from the prime mover 11 and outputs the rotation to the driven device 12 .

[0020] Hereinafter, the rotation of the prime mover 11 refers to the rotation of an object rotating in the prime mover 11, and in this example refers to the rotation of the prime mover shaft 13. Furthermore, the rotation of the driven device 12 refers to the rotation of an object rotating in the driven device 12.

[0021] The speed change mechanism 24 changes the speed of the rotation input to the input shaft 22 and then transmits it to the output shaft 25. The speed change ratio change mechanism 23 changes the speed change ratio of the speed change mechanism 24. The variable speed transmission mechanism 27 transmits the rotation input to the input shaft 22 on the input side to the transmission shaft 26 on the non-input side without changing the speed, that is, without changing the speed. In other words, the variable speed transmission mechanism 27 of this embodiment transmits the rotation input to the input shaft 22 to the transmission shaft 26, bypassing the speed change mechanism 24. The rotation transmitted to the transmission shaft 26 is input to the input shaft of a subsequent transmission.

[0022] The transmission actuator 15 is capable of changing the gear ratio of the transmission 21 by inputting power to the transmission 21 based on control information from a control means (not shown). The transmission actuator 15 of this embodiment is a linear actuator, and inputs power to the transmission 21 along the axial direction of the transmission 21. The specific type of the transmission actuator 15 is not particularly limited as long as it can change the gear ratio of the transmission 21, and it may be a rotary actuator or the like.

[0023] The prime mover 11 is capable of rotating the driving shaft 13 by torque generated therein and outputting the rotation from the driving shaft 13 to the transmission 21. The prime mover 11 of this embodiment is an electric motor that uses electrical energy to rotate the driving shaft 13. The motor is capable of rotating the driving shaft 13 by torque generated by the cooperation of a stator and a rotor.

[0024] A specific configuration of the transmission 21 of this embodiment will be described. The transmission 21 is capable of continuously (steplessly) changing the actual gear ratio, which is the actual gear ratio, using the gear ratio changing mechanism 23 via the gear actuator 15. The gear ratio here refers to the ratio of the output rotational speed, which is the rotational speed of the output shaft 25, to the input rotational speed, which is the rotational speed of the input shaft 22 (= output rotational speed / input rotational speed). The transmission 21 of this embodiment is an infinitely variable transmission (IVT) with an infinitely variable gear ratio, and is configured so that the variable range of the actual gear ratio includes zero (= 1 / ∞). Here, an example of such a transmission 21 will be described, but the specific example is not particularly limited.

[0025] The input shaft 22 includes an input member 221 to which rotation is input from the prime mover 11, a shaft 222 connected to the input member 221, and a sleeve 223 fixed to the shaft 222. The specific structure of the input shaft 22 is not particularly limited as long as it can transmit rotation from the prime mover 11 to the transmission mechanism 24. Here, the input shaft 22 is shown as being made up of multiple members by way of example, but it may also be made up of a single member, and the number of members is not particularly limited.

[0026] The speed change mechanism 24 includes an input raceway 40 provided on the input shaft 22 so as to be rotatable therewith, a first support raceway 42 rotatably supported on the input shaft 22, a second support raceway 46 provided axially movably within a casing 44 of the transmission 21, an output raceway 48 provided on the output shaft 25 so as to be rotatable therewith, and a plurality of planetary rolling elements 41 that roll on the raceways 40, 42, 46, 48. The plurality of planetary rolling elements 41 are pressed against the output raceway 48 by a pressing force applied from the second support raceway 46 by a pressing force applying mechanism (not shown).

[0027] When the input bearing ring 40 rotates, the planetary rolling elements 41 rotate about the rotation axis LB while revolving around the rotation axis LA, which is the orbital axis of the input shaft 22. As the planetary rolling elements 41 revolve, the output bearing ring 48 rotates about the rotation axis LA in response. Ideally, the output bearing ring 48 rotates at an output rotation speed obtained by multiplying the input rotation speed of the input shaft 22 by the gear ratio. This gear ratio is determined according to the inclination angle of the rotation axis LB with respect to the rotation axis LA, and is changed by the gear ratio change mechanism 23.

[0028] The output shaft 25 includes an output bearing ring 48 and an output member 251 that is connected to the output bearing ring 48 so as to rotate integrally with the output bearing ring 48 and outputs rotation to the driven device 12. The specific structure of the output shaft 25 is not particularly limited as long as it can transmit rotation from the speed change mechanism 24 to the driven device 12. Here, the output shaft 25 is shown as being made up of multiple members, but it may also be made up of a single member, and the number of members is not particularly limited.

[0029] The gear ratio change mechanism 23 of this embodiment is able to change the gear ratio by changing the attitude of the input race 40. The gear ratio change mechanism 23 includes a shaft 231 that is movable in the axial direction by power output from the gear change actuator 15, and a ring member 232 that is movable in the axial direction integrally with the shaft 231. The ring member 232 rotatably supports the input shaft 22 via a bearing 233, and is able to move in the axial direction integrally with the input shaft 22 by a snap ring or the like. There are no particular limitations on the specific example of the gear ratio change mechanism 23, and various mechanisms similar to those employed in the transmission 21 may be employed.

[0030] When axial power is input from the speed change actuator 15 to the shaft 231, the input shaft 22, including the input race 40 and the first support race 42, moves axially together with the ring member 232. The axial movement of the input race 40 and the first support race 42 relative to the second support race 46 and the output race 48 changes the inclination angle of the rotation axis LB of the planetary rolling elements 41 relative to the rotation axis LA, changing the gear ratio according to that inclination angle. This gear ratio is zero (= 1 / ∞) when the rotation axis LB is parallel to the rotation axis LA, and continuously increases as the inclination angle of the rotation axis LB relative to the rotation axis LA increases. In other words, the actual gear ratio can be changed continuously (steplessly), and the variable range is configured to include zero.

[0031] The present applicant has disclosed examples of infinitely variable speed ratio continuously variable transmissions in Japanese Patent Application Laid-Open No. 2021-181812, Japanese Patent Application Laid-Open No. 2022-135086, etc., and the technology of continuously variable transmissions will be understood by those skilled in the art.

[0032] The variable speed transmission mechanism 27 includes an input member 221 to which rotation is input from the prime mover 11, a shaft 222 connected to the input member 221, and a transmission shaft 26 connected to the shaft 222. In other words, the input member 221 and the shaft 222 are shared with the transmission mechanism 24. The transmission shaft 26 in this example has a configuration symmetrical to that of the input member 221. The transmission shaft 26 is connected to an input portion of the rear device 18. The variable speed transmission mechanism 27 outputs the rotation input to the input member 221 from the transmission shaft 26 via the shaft 222, thereby rotating the input portion of the rear device 18 connected to the transmission shaft 26. For example, the rear device 18 is the rear-stage change gear unit 20.

[0033] Returning to Figure 2, the parent machine 100 includes a prime mover 11, a first transmission 21A that changes the speed of the rotation of the prime mover 11, a second transmission 21B that changes the speed of the rotation of the prime mover 11 in parallel with the first transmission 21A, and a third transmission 21C that changes the speed of the rotation of the prime mover 11 in parallel with the first transmission 21A. "Multiple transmissions changing the speed of the rotation of the prime mover in parallel" means that the rotation of the prime mover is input to multiple transmissions in parallel. "The rotation of the prime mover is input to multiple transmissions in parallel" does not mean that the rotation of the prime mover whose speed has been changed by another transmission is input to one of the multiple transmissions, but rather that the rotation of the prime mover is input to one transmission regardless of the gear ratio of the other transmissions. The first transmission 21A, the second transmission 21B, and the third transmission 21C are continuously variable transmissions whose gear ratios are variable, including a gear ratio of 0.

[0034] As an example, the parent machine 100 has a first arm 91 driven by the output rotation of the first transmission 21A, a second arm 92 driven by the output rotation of the second transmission 21B, and an upper and lower unit 93 driven by the output rotation of the third transmission 21B.

[0035] A more detailed description will be given below. The driving shaft 13 of the prime mover 11 is connected to the input shaft 22A of the transmission 21A of the speed change unit 20A of the first joint 95, and the rotation of the prime mover 11 is input to the input shaft 22A of the transmission 21A. At the first joint 95, the transmission 21A outputs a variable-speed rotation from the output shaft 25A to the first arm 91, which is the driven device, thereby causing the first arm 91 to swing. The operation of the first arm 91 can be controlled by changing the gear ratio of the transmission 21A using the speed change actuator 15A.

[0036] The rotation of the prime mover 11 input to the input shaft 22A is transmitted to a pulley 28A fixed to the transmission shaft 26A via a variable-speed transmission mechanism of the transmission 21A. The rotation of the pulley 28A is transmitted to the intermediate shaft 14 via an annular transmission body 29A and a pulley 30B. The pulley 28A, the annular transmission body 29A, and the pulley 30B are disposed between the prime mover 11 and the second transmission 21B and constitute a rotation transmission mechanism 36 that transmits the rotation of the prime mover 11 to the second transmission 21B. The pulley 28A is a rotating member on the input side of the rotation transmission mechanism 36 and is located on a rotation axis L1 of the first arm 91. The pulley 30B is a rotating member on the output side of the rotation transmission mechanism 36 and is located on a rotation axis L2 of the second arm 92. As shown in FIG. 2 , the rotation transmission mechanism 36 is disposed within the hollow first arm 91. This reduces the possibility of malfunction due to foreign matter adhering to the rotation transmission mechanism 36, compared to when the rotation transmission mechanism 36 is disposed outside the first arm 91. There are no particular limitations on the specific example of the rotation transmission mechanism 36, and it may be, for example, a gear mechanism, a combination of a chain and a sprocket, or the like.

[0037] Hereinafter, a looped endless belt that transmits rotation between multiple pulleys will be simply referred to as a "belt," and a looped endless wire that transmits rotation between multiple pulleys will be simply referred to as a "wire," and belts and wires are included in the annular transmission body.

[0038] The intermediate shaft 14 is connected to an input shaft 22B of a transmission 21B of a speed change unit 20B of the second joint 96, and rotation of the intermediate shaft 14 is input to the input shaft 22B of the transmission 21B. At the second joint 96, the transmission 21B outputs a variable-speed rotation from an output shaft 25B to a second arm 92, which is a driven device, thereby causing the second arm 92 to swing. The operation of the second arm 92 can be controlled by changing the gear ratio of the transmission 21B with a speed change actuator 15B.

[0039] The rotation of the intermediate shaft 14 input to the input shaft 22B is transmitted to a pulley 28B fixed to the transmission shaft 26B via the variable-speed transmission mechanism of the transmission 21B. The rotation of the pulley 28B is transmitted to the input shaft 22C of the transmission 21C via an annular transmission body 29B and a pulley 30C. The pulley 28B, the annular transmission body 29B, and the pulley 30C are disposed between the prime mover 11 and the third transmission 21C and constitute a rotation transmission mechanism 38 that transmits the rotation of the prime mover 11 to the third transmission 21C. The pulley 28B is a rotating member on the input side of the rotation transmission mechanism 38 and is located on the rotation axis L2 of the second arm 92. The pulley 30C is a rotating member on the output side of the rotation transmission mechanism 38 and is located on the rotation axis L3 of the upper / lower unit 93. As shown in FIG. 3 , the rotation transmission mechanism 38 is disposed within the hollow second arm 92. This reduces the possibility of malfunction due to foreign matter adhering to the rotation transmission mechanism 38, compared to when the rotation transmission mechanism 38 is disposed outside the second arm 92. There are no particular limitations on the specific example of the rotation transmission mechanism 38, and it may be, for example, a gear mechanism, or a combination of a chain and a sprocket, etc.

[0040] At the third joint 97, rotation of the input shaft 22C outputs a variable-speed rotation from the output shaft 25C of the transmission 21C to the up / down unit 93, which is a driven device. The input shaft 22C and the output shaft 25C are hollow shafts through which the up / down unit 93 passes vertically without contacting each other. The up / down unit 93 is configured to move vertically by transmitting rotation from the output shaft 25C of the transmission 21C. The operation of the up / down unit 93 can be controlled by changing the gear ratio of the transmission 21C using the gear change actuator 15C.

[0041] The master machine 100 configured as described above controls the first arm 91, the second arm 92, and the upper and lower units 93 independently of one another by rotating the single prime mover 11, thereby realizing the desired operation.

[0042] In the description of FIG. 4 , an example was shown in which multiple transmissions 21 are connected in a cascade with their variable speed transmission mechanisms, and the rotation of the prime mover 11 is transmitted in stages via the variable speed transmission mechanisms of the transmissions 21, but the present disclosure is not limited to this. For example, the rotation of the prime mover 11 may be transmitted using an independent transmission mechanism without using a variable speed transmission mechanism. Also, in the description of FIG. 4 , an example was shown in which multiple transmissions 21 are distributed and arranged on each arm, but the present disclosure is not limited to this. For example, the multiple transmissions 21 may be arranged centrally within a predetermined space. Below, a description is given of a parent machine 200 to which these modifications are applied to the parent machine 100.

[0043] A parent machine 200 according to a modified example of the parent machine 100 will be described with reference to Fig. 5. Fig. 5 is a schematic diagram showing the parent machine 200 according to the modified example. The configuration example in Fig. 5 differs from the configuration example in Fig. 4 in that multiple transmissions 21A, 21B, 21C are centrally arranged within the stationary link 90, and the rotation of the output shafts 25B, 25C of the transmissions 21B, 21C is transmitted using an annular transmission body. The following description will omit redundant explanations and focus on the differences.

[0044] In the parent machine 200, the rotation of the prime mover 11 is transmitted to the input shaft 22A of the transmission 21A via the drive shaft 13. The rotation of the prime mover 11 is also transmitted to the input shaft 22B of the transmission 21B via the drive shaft 13, pulley 33B, annular transmission body 34B, and pulley 35B. The rotation of the prime mover 11 is also transmitted to the input shaft 22C of the transmission 21C via the drive shaft 13, pulley 33A, annular transmission body 34A, and pulley 35A. The annular transmission bodies 34A and 34B may be wires, but in this example they are belts.

[0045] The transmission 21A changes the speed of the rotation transmitted to the input shaft 22A and outputs the rotation to the output shaft 25A. As a result, the output shaft 25A rotates about the rotation axis L1, swinging the first arm 91. The operation of the first arm 91 can be controlled by changing the gear ratio of the transmission 21A using the speed change actuator 15A.

[0046] The transmission 21B changes the speed of the rotation transmitted to the input shaft 22B and outputs it to the output shaft 25B. The rotation of the output shaft 25B is transmitted to the shaft member 35 to which the pulley 30E is fixed via the pulley 30C, the annular transmission body 29B, and the pulley 30E fixed to the output shaft 25B. This causes the shaft member 35 to rotate about the rotation axis L2, causing the second arm 92 to swing. The operation of the second arm 92 can be controlled by changing the gear ratio of the transmission 21B with the speed change actuator 15B. The shaft member 35 is a hollow shaft, and the intermediate shaft 34 passes through it without contacting it.

[0047] The transmission 21C changes the speed of the rotation transmitted to the input shaft 22C and outputs it to the output shaft 25C. The rotation of the output shaft 25C is transmitted to the intermediate shaft 34 to which the pulley 30F is fixed via a pulley 30D, an annular transmission body 29C, and a pulley 30F fixed to the output shaft 25C. The rotation of the intermediate shaft 34 is transmitted to the upper and lower unit 93 via a pulley 30G, an annular transmission body 29D, and a pulley 30H fixed to the intermediate shaft 34. As a result, the upper and lower unit 93 is configured to rotate about the rotation axis L3 and move up and down. The operation of the upper and lower unit 93 can be controlled by changing the gear ratio of the transmission 21C using the speed change actuator 15C.

[0048] In this example, the annular transmission bodies 29B, 29C, and 29D of the parent machine 200 are wires, but they may also be belts. In the case of a multi-joint part, the two rotation axes involved in the rotation transmission may not be parallel, and in this case, it has been found that wires have better ability to follow the movements of the two rotation axes.

[0049] The modified master machine 200 configured as described above controls the first arm 91, the second arm 92, and the upper and lower units 93 independently of one another by rotating the single prime mover 11, thereby realizing the desired operation.

[0050] Second Embodiment A parent machine 300 according to a second embodiment of the present disclosure will be described with reference to Figures 6 to 8. Figure 6 is a side view showing the parent machine 300 according to the second embodiment. Figure 7 is a schematic diagram showing the configuration of the parent machine 300. Figure 8 is a schematic diagram showing the configuration of a self-propelled carriage 700 according to a comparative example. In the following description, components denoted with the same reference numerals as those in the first embodiment are the same or equivalent components as those in the first embodiment, and the description of the first embodiment applies unless otherwise specified.

[0051] As shown in Figure 6, the parent machine 300 of this embodiment is a transport vehicle having a vehicle body 50 and multiple wheels 52, 53, 54, and 55. The multiple wheels 52, 53, 54, and 55 are collectively referred to as wheels 56. In this example, the wheels 52 and 53 are front wheels, and the wheels 54 and 55 are rear wheels. The parent machine 300 of this example is provided with an articulated robot 80. This allows the parent machine 300 to travel to any position and perform work using the articulated robot 80.

[0052] In this embodiment, wheels 56 for traveling are provided on the output side of the first transmission 21A, the output side of the second transmission 21B, the output side of the third transmission 21C, and the output side of the fourth transmission 21D. Various known types of wheels can be used as the wheels 56. As an example, in addition to tires, Mecanum wheels, omni wheels, etc. can be used as the wheels 56.

[0053] First, a comparative example of a self-propelled carriage 700 will be described with reference to Figure 8. The self-propelled carriage 700 was created for comparison purposes during the development process of the parent machine 300. As shown in Figure 8, the self-propelled carriage 700 differs from the parent machine 300 in that a set of a motor 98 and a reducer 99 is provided corresponding to each of the two front wheels 52 and 53 and the two rear wheels 54 and 55, but the other configurations are similar. In other words, the self-propelled carriage 700 has four sets of a motor 98 and a reducer 99. Each reducer 99 is configured to reduce the rotation input from the corresponding motor 98 and output it to rotate and drive the wheel 56.

[0054] In the self-propelled carriage 700, the speed reducer 99 has a fixed gear ratio, and the output rotation speed and rotation direction are controlled by the motor 98. The self-propelled carriage 700 can move forward, backward, turn, and stop by individually controlling the rotation of each motor 98. The self-propelled carriage 700 uses as many motors 98 as there are wheels 56, and therefore the number of motors 98 increases in accordance with the number of wheels 56, resulting in increased consumption of motor raw materials such as copper and rare metals.

[0055] The parent machine 300 of this embodiment will be described based on the description of the comparative example. The inventor conceived of a configuration in which a single prime mover 11 drives multiple wheels 56 in order to reduce raw material consumption. However, it was found that using a speed reducer with a fixed gear ratio makes it difficult to independently control multiple wheels 56 because the output rotation speed and rotation direction of the reducer are fixed to the rotation speed and rotation direction of the single prime mover. Therefore, the inventor devised a configuration in which, in order to independently control multiple wheels 56, each of the multiple wheels 56 is provided with a transmission unit 20 including a transmission 21 with a variable gear ratio. The description of the transmission 21 in the first embodiment is applicable to the transmission 21.

[0056] 7 , in the parent machine 300, a transmission unit 20A is provided on a wheel 52, a transmission unit 20B is provided on a wheel 53, a transmission unit 20C is provided on a wheel 54, and a transmission unit 20D is provided on a wheel 55. In the parent machine 300, the transmission units 20A, 20B, 20C, and 20D change the speed of rotation input in parallel from a single prime mover 11 provided on a base 51 of the body 50 to drive each wheel 56. In the parent machine 300, each wheel 56 does not have its own dedicated prime mover 11, so the number of prime movers 11 is reduced, and the amount of raw material consumed by the prime movers 11 can be reduced.

[0057] Although the location of the prime mover 11 is not limited, in this example, the prime mover 11 is located in the center of the width direction between the front and rear wheels in the longitudinal direction. A pulley 61 is fixed to the output shaft of the prime mover 11, and the pulley 61 rotates when the prime mover 11 rotates. The rotation of the pulley 61 is transmitted to pulleys 62 and 63 via an annular transmission body 65. The pulleys 62 and 63 are fixed to axles 66 and 67, respectively, and the axles 66 and 67 rotate integrally with the pulleys 62 and 63.

[0058] One end of the axle 66 is connected to the input shaft 22A of the transmission 21A of the transmission unit 20A, and the other end of the axle 66 is connected to the input shaft 22B of the transmission 21B of the transmission unit 20B. One end of the axle 67 is connected to the input shaft 22C of the transmission 21C of the transmission unit 20C, and the other end of the axle 67 is connected to the input shaft 22D of the transmission 21D of the transmission unit 20D.

[0059] An output shaft 25A of the transmission 21A is connected to a wheel 52, and an output shaft 25B of the transmission 21B is connected to a wheel 53. An output shaft 25C of the transmission 21C is connected to a wheel 54, and an output shaft 25D of the transmission 21D is connected to a wheel 55.

[0060] The rotational speed and direction of the wheels 52 can be controlled by changing the speed ratio of the transmission 21A using the speed change actuator 15A. The rotational speed and direction of the wheels 53 can be controlled by changing the speed ratio of the transmission 21B using the speed change actuator 15B. The rotational speed and direction of the wheels 54 can be controlled by changing the speed ratio of the transmission 21C using the speed change actuator 15C. The rotational speed and direction of the wheels 55 can be controlled by changing the speed ratio of the transmission 21D using the speed change actuator 15D. In this way, the parent machine 300 can move forward, backward, turn, and stop by independently controlling the rotational speed and direction of each wheel 56.

[0061] The parent machine 300 configured as described above controls the wheels 52, 53, 54, and 55 independently of one another by the rotation of the single prime mover 11, thereby realizing the desired traveling operation.

[0062] A parent machine 400 according to a first modified example of the parent machine 300 will be described with reference to FIG. 9 . FIG. 9 is a schematic diagram showing the parent machine 400 according to the first modified example. In the description of the parent machine 300, an example was shown in which the parent machine has a transmission but no speed reducer, but the present disclosure is not limited to this. The parent machine may also be configured to use both a transmission and a speed reducer. The parent machine 400 in FIG. 9 differs from the parent machine 300 in that a speed reducer 99 is provided between the output shaft 25 of the transmission 21 and the wheels 56. The following description will omit redundant explanations and focus on the differences.

[0063] In the parent machine 400, a reducer 99 is provided downstream of each of the transmissions 21A, 21B, 21C, and 21D. Specifically, in addition to the transmissions 21A, 21B, 21C, and 21D, the parent machine 400 is equipped with a reducer 99 that reduces the rotation of the output shafts 25A, 25B, 25C, and 25D of the transmissions 21A, 21B, 21C, and 21D at a fixed reduction ratio and transmits the rotation to the wheels 52, 53, 54, and 55. With the parent machine 400, by using the transmissions 21A, 21B, 21C, and 21D in combination, the range of the total gear ratio can be flexibly expanded.

[0064] The parent machine 400 of the first modified example configured as described above controls the wheels 52, 53, 54, and 55 independently of one another by the rotation of the single prime mover 11, thereby realizing the desired traveling operation.

[0065] A parent machine 500 according to a second modified example of the parent machine 300 will be described with reference to FIG. 10 . FIG. 10 is a schematic diagram showing the parent machine 500 according to the second modified example. In the description of the parent machine 300, an example was shown in which the parent machine drives wheels and does not drive other elements, but the present disclosure is not limited to this. The parent machine may be configured to drive multiple different types of drive elements with the rotation of a single prime mover. The parent machine 500 in FIG. 10 differs from the parent machine 300 in that the rotation of a single prime mover 11 drives wheels 56 and also drives an articulated robot 80. The following description will omit redundant explanations and focus on the differences. Note that the parent machine 500, like the parent machine 400, has a reducer 99 provided between the output shaft 25 of the transmission 21 and the wheels 56.

[0066] The articulated robot 80 has an orthogonal axis reducer 81, a first variable speed unit 20A, a second variable speed unit 20B, and a third variable speed unit 20C. The variable speed actuators of the variable speed units are not shown in Fig. 10. The first variable speed unit 20A swings a first arm 91 in response to the rotation of the prime mover 11. The second variable speed unit 20B swings a second arm 92 in response to the rotation of the prime mover 11. The third variable speed unit 20C moves an end effector (not shown) in response to the rotation of the prime mover 11.

[0067] The rotation of the prime mover 11 is transmitted from the axle 66 to the first change gear unit 20A via the orthogonal axis reducer 81. The rotation of the prime mover 11 is also transmitted to the second change gear unit 20B by the transmission mechanism 82. The rotation of the prime mover 11 is also transmitted to the third change gear unit 20C by the transmission mechanisms 82 and 84. As an example, the transmission mechanisms 82 and 84 transmit the rotation by an annular transmission body and a pulley. The configurations of the transmission mechanisms 82 and 84 in the parent machine 500 can be applied to the configurations of the parent machines 100 and 200.

[0068] The parent machine 500 of the second modified example configured as described above controls the wheels 52, 53, 54, and 55 independently of one another by the rotation of the single prime mover 11, thereby realizing the desired running operation, and also controls the first arm 91 and the second arm 92 independently of one another by the rotation of the prime mover 11, thereby realizing the desired operation.

[0069] The features of the parent machines 100, 200, 300, 400, and 500 configured as described above will be described below. The parent machines 100, 200, 300, 400, and 500 each include a prime mover 11, a first transmission 21A that changes the speed of the rotation of the prime mover 11, and a second transmission 21B that is parallel to the first transmission 21A and changes the speed of the rotation of the prime mover 11. The first transmission 21A and the second transmission 21B are continuously variable transmissions whose gear ratios are variable, including a gear ratio of 0.

[0070] This configuration makes it possible to reduce the number of prime movers 11 used and reduce the amount of raw materials consumed for the prime movers 11. Furthermore, because no prime movers are provided at the joints, this is advantageous for reducing the weight of the joints, which in turn is advantageous for reducing the weight of the parent machines 100, 200, 300, 400, and 500. Note that the parent machines may partially include other reducers.

[0071] The above description is based on the embodiments and their modifications. These are merely examples, and it will be understood by those skilled in the art that various modifications and variations are possible and that such modifications and variations are also within the scope of the present disclosure. Therefore, the descriptions and drawings in this specification should be treated as illustrative rather than restrictive.

[0072] Other modifications will be described below. In the following description and drawings, the same reference numerals will be used to designate components and members that are the same as or equivalent to those in the embodiment. Explanations that overlap with the above description will be omitted as appropriate, and the description will focus on the differences from the above description.

[0073] In the above description, an example in which the prime mover 11 is an electric motor has been described, but the present disclosure is not limited to this. Specific examples of the prime mover 11 are not particularly limited, and may be, for example, an engine that uses thermal energy to rotate the drive shaft 13, a water wheel that uses the kinetic energy of water to rotate the drive shaft, a windmill that uses the kinetic energy of air to rotate the drive shaft, or the like.

[0074] Although the above description shows an example in which the present disclosure is applied to an articulated SCARA robot and a traveling device, the present disclosure is not limited thereto. The present disclosure can be applied to a master machine based on known principles and having multiple drive parts.

[0075] Although the above description has shown an example in which the rotation of the prime mover 11 is transmitted by an annular transmission body and a pulley, the present disclosure is not limited to this. The mechanism for transmitting the rotation of the prime mover 11 to the transmission unit 20 may include transmission mechanisms based on various known principles, such as gears, toothed belts, and couplings such as universal joints.

[0076] In the above description, an example has been shown in which the prime mover 11 is disposed in the stationary joint 90, but the present disclosure is not limited to this. The prime mover may be disposed in a location other than the stationary joint, such as within the arm.

[0077] Each of these modifications provides the same functions and effects as the embodiment.

[0078] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present disclosure. A new embodiment resulting from the combination has the combined effects of the combined embodiments and modifications.

[0079] The present disclosure relates to a parent machine.

[0080] 11 prime mover, 15 variable speed actuator, 20 variable speed unit, 21 transmission, 36 rotation transmission mechanism, 56 wheel, 90 stationary link, 91 first arm, 92 second arm, 100, 200, 300, 400, 500 parent machine.

Claims

1. A main machine comprising a prime mover, a first transmission for changing the rotation speed of the prime mover, and a second transmission for changing the rotation speed of the prime mover in parallel with the first transmission, wherein the first transmission and the second transmission are continuously variable transmissions including a transmission ratio of 0 and having a variable transmission ratio.

2. The main machine according to claim 1, further comprising a first arm driven by the output rotation of the first transmission, a second arm connected to the tip side of the first arm and driven by the output rotation of the second transmission, and a rotation transmission mechanism disposed between the prime mover and the second transmission.

3. The main machine according to claim 2, wherein the rotating member on the input side of the rotation transmission mechanism is located on the rotation axis of the first arm.

4. The main machine according to claim 2 or 3, wherein the rotation transmission mechanism is disposed within the first arm.

5. The main machine according to any one of claims 1 to 4, having a first arm that moves relative to a stationary node and a second arm that moves relative to the first arm, wherein the prime mover is disposed at the stationary node.

6. The main machine according to claim 1, wherein traveling wheels are respectively provided on the output sides of the first transmission and the second transmission.

7. The main machine according to claim 6, wherein a speed reducer is provided respectively downstream of the first transmission and the second transmission.

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