Wire drive mechanism

Abstract

To provide a wire drive mechanism capable of reducing its size and weight, and reducing friction of a wire.SOLUTION: When winding a first wire 3 wound around a first driven pulley 11 around a second rotational shaft drive pulley 13, the first wire 3 is wound around the second rotational shaft drive pulley 13 via a single first change pulley 14 that changes the direction of the first wire 3, and when winding a second wire 4 wound around the first driven pulley 11 around the second rotational shaft drive pulley 13, the second wire 4 is wound around the second rotational shaft drive pulley 13 via a single second change pulley 15 that changes the direction of the second wire 4.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a wire drive mechanism that transmits power by wire.

Background Art

[0002] In recent years, robots have been explored for use in replacing or collaborating with humans in various environments. For example, various service robots with arms have been developed that move near people and perform auxiliary work for people to support people's lives.

[0003] By the way, conventionally, when configuring a robot arm as described above, it is known to arrange an actuator at a joint portion of the arm and drive the joint portion by this actuator.

[0004] However, in this case, since an actuator is required for all joint portions, there is a problem that the weight of the entire robot increases.

[0005] Therefore, in order to solve such a problem, a wire drive mechanism has been proposed in which an actuator is arranged not at the joint portion but on the robot body side, and power is transmitted from the robot body side to the joint using a wire (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the wire drive mechanism described above had a problem: when the axial direction changed between the front and rear links as the movement passed through a joint, such as the adduction / abduction axis or flexion / extension axis in the hip joint, multiple pulleys were required to change the direction of the wire, resulting in an overall increase in weight and size. Furthermore, the need for multiple pulleys to change the direction of the wire increased friction in the wire, potentially leading to wire breakage, wear, or loosening.

[0008] Therefore, in view of the above problems, the present invention aims to provide a wire drive mechanism that can be miniaturized and made lighter, while also reducing wire friction. [Means for solving the problem]

[0009] The object of the present invention described above is achieved by the following means. The reference numerals in parentheses indicate the embodiments described later, but the present invention is not limited thereto.

[0010] The wire drive mechanism according to claim 1 is arranged on the first rotation axis (Z1). Singular The first pulley (first driven pulley 11) and, It is positioned on the second rotation axis (Z2), which is located in a direction intersecting the first rotation axis (Z1). Singular The second pulley (second rotating shaft drive pulley 13) and, A first wire (3) is wound around the first pulley (first driven pulley 11) and the second pulley (second rotating shaft drive pulley 13), A second wire (4) is wound around the first pulley (first driven pulley 11) and the second pulley (second rotating shaft drive pulley 13), The first wire (3) and the second wire (4) are wrapped around a drive pulley (2) such that when one wire is pulled, the other wire is pushed out. The drive pulley (2) is rotatably mounted, and the actuator (1) pulls the first wire (3) and the second wire (4) in an antagonistic manner. When winding the first wire (3) which is wound around the first pulley (first driven pulley 11) around the second pulley (second rotating shaft drive pulley 13), a single first changing pulley (first changing pulley 14) is used to guide the wire from the direction of the first tangent (11a) of the first pulley (first driven pulley 11) to the direction of the first tangent (13a) of the second pulley (second rotating shaft drive pulley 13), The system includes a single second changing pulley (second changing pulley 15) that guides the second wire (4), which is wound around the first pulley (first driven pulley 11), to be wound around the second pulley (second rotating shaft drive pulley 13), from the direction of the second tangent (11b) of the first pulley (first driven pulley 11) to the direction of the second tangent (13b) of the second pulley (second rotating shaft drive pulley 13), The first wire (3) is wrapped around the outer surfaces of the first pulley (first driven pulley 11) and the second pulley (second rotating shaft drive pulley 13) so as to cover only a portion of them, not the entire surface. The second wire (4) is wrapped around the outer surfaces of the first pulley (first driven pulley 11) and the second pulley (second rotating shaft drive pulley 13) so as to cover only a portion of them, not the entire surface. The first changing pulley (first changing pulley 14) is positioned where the first tangent (11a) of the first pulley (first driven pulley 11) and the first tangent (13a) of the second pulley (second rotating shaft drive pulley 13) intersect, and when the axial direction of the first pulley (first driven pulley 11) and the axial direction of the second pulley (second rotating shaft drive pulley 13) intersect in the vertical up-and-down direction, the axial direction of the first changing pulley (first changing pulley 14) is positioned toward the vertical up-and-down direction. The second change pulley (second change pulley 15) is positioned where the second tangent (11b) of the first pulley (first driven pulley 11) and the second tangent (13b) of the second pulley (second rotating shaft drive pulley 13) intersect. Furthermore, when the axial direction of the first pulley (first driven pulley 11) and the axial direction of the second pulley (second rotating shaft drive pulley 13) intersect in the vertical direction, the axial direction of the second change pulley (second change pulley 15) is positioned where they intersect in the vertical direction. It is characterized by the following.

Advantages of the Invention

[0012] Next, the effects of the present invention will be described with reference numerals in the drawings. The reference numerals in parentheses are those of the embodiments described later, but the present invention is not limited thereto.

[0013] According to the invention of claim 1, when changing the direction of the first wire (3), one first change pulley (first change pulley 14) is arranged, and when changing the direction of the second wire (4), one second change pulley (second change pulley 15) is arranged. Therefore, there is no need to arrange a plurality of change pulleys for the wire whose direction is to be changed as in the prior art. Also, since the number of change pulleys is singular, the friction between the first wire (3) and the second wire (4) can be reduced.

[0014] Thus, according to the present invention, it is possible to reduce the size and weight, and also to reduce the friction of the wire.

[0015] In arranging such a first change pulley (first change pulley 14), claim 1 described in When the first tangent (11a) of the first pulley (first driven pulley 11) and the first tangent (13a) of the second pulley (second rotating shaft drive pulley 13) intersect, and the axial direction of the first pulley (first driven pulley 11) and the axial direction of the second pulley (second rotating shaft drive pulley 13) intersect in the vertical direction, the axial direction of the first change pulley (first change pulley 14) is positioned in the vertical direction. is preferable That is the case. Furthermore, in arranging the second change pulley (second change pulley 15), claim 1 described in The second change pulley (second change pulley 15) is positioned where the second tangent (11b) of the first pulley (first driven pulley 11) and the second tangent (13b) of the second pulley (second rotating shaft drive pulley 13) intersect, and the axial direction of the first pulley (first driven pulley 11) and the axial direction of the second pulley (second rotating shaft drive pulley 13) intersect in the vertical direction. is preferable.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic diagram for explaining a state in which a wire drive mechanism according to an embodiment of the present invention is provided on a link of a robot. [Figure 2] It is a perspective explanatory diagram for explaining a case where the wire drive mechanism according to the embodiment is applied to a link of a robot in which the first rotation axis and the second rotation axis are not parallel. [Figure 3]It is a perspective explanatory view when viewing the content shown in FIG. 2 from another direction. [Figure 4] It is a perspective explanatory view for explaining that the wire drive mechanism according to this embodiment can also be applied when there is a third rotation axis.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the wire drive mechanism according to an embodiment of the present invention will be specifically described with reference to the drawings. In the following description, when indicating the up, down, left, and right directions, it shall refer to the up, down, left, and right when viewed from the front shown in the drawings.

[0018] <统一替换为 The wire drive mechanism according to this embodiment is a wire drive mechanism that pulls the wire antagonistically, and is provided, for example, on the link of a robot as shown in FIG. 1. More specifically, this link of the robot is composed of a first link R1 and a second link R2, and the first link R1 and the second link R2 are connected to each other via a joint portion K1 so as to be relatively displaceable.

[0019] By the way, as shown in FIG. 1, one actuator 1 is provided on the left end surface R1a side of the first link R1, and a drive pulley 2 is rotatably attached to the output shaft 1a of this actuator 1. And the first wire 3 and the second wire 4 are wound around the drive pulley 2. Thereby, when the drive pulley 2 rotates by the actuator 1, one wire (for example, the first wire 3) is pulled and the other wire (for example, the second wire 4) is pushed out. And the first wire 3 and the second wire 4 are wound around the driven pulley 5 provided at the joint portion K1, and further wound around other joint portions. Thereby, it is possible to drive a plurality of joint portions by driving one actuator 1.

[0020] Herein, a key feature of the present invention is that the wire drive mechanism described above is provided on a non-parallel rotating shaft. This point will be explained in detail with reference to Figures 2 and 3.

[0021] As shown in Figures 2 and 3, if there is a robot link where the first rotation axis Z1 and the second rotation axis Z2 are not parallel (orthogonal in the figures), the wire drive mechanism according to this embodiment is configured as follows.

[0022] As shown in Figure 2, a first rotating shaft drive pulley 10 is positioned on the first rotating shaft Z1, which rotates on the first rotating shaft Z1. Then, as shown in Figures 2 and 3, a first driven pulley 11 is positioned on the first rotating shaft Z1, which rotates in conjunction with the rotation of the first rotating shaft drive pulley 10. As shown in Figures 2 and 3, the first wire 3 and the second wire 4, which have been guided via the intermediate pulley 12, are wound around this first driven pulley 11.

[0023] On the other hand, as shown in Figures 2 and 3, a second rotating shaft drive pulley 13 is positioned on the second rotating shaft Z2 and rotates on the second rotating shaft Z2. The first wire 3 and the second wire 4, which are wound around the first driven pulley 11, are wound around this second rotating shaft drive pulley 13, as shown in Figures 2 and 3.

[0024] To explain this point in more detail, the first rotation axis Z1 and the second rotation axis Z2 are not parallel (they are perpendicular in the diagram). Therefore, if the first wire 3 and the second wire 4, which are wound around the first driven pulley 11, are to be wound around the second rotation axis drive pulley 13, the direction of the first wire 3 and the second wire 4 must be changed. Conventionally, in order to change the direction of the first wire 3 and the second wire 4, it was necessary to arrange multiple pulleys for changing the direction of the first wire 3, and furthermore, multiple pulleys for changing the direction of the second wire 4. As a result, the entire wire drive mechanism became heavier and larger. Moreover, if multiple pulleys are required to change the direction of the first wire 3 and the second wire 4, the friction generated in the first wire 3 and the second wire 4 increases, which can lead to the first wire 3 and the second wire 4 being cut, worn, or loosened.

[0025] Therefore, in this embodiment, as shown in Figures 2 and 3 (see Figure 3 in particular), one first changing pulley 14 is provided to change the direction of the first wire 3, and one second changing pulley 15 is provided to change the direction of the second wire 4.

[0026] However, this approach eliminates the need to place multiple pulleys for changing the direction of the wire, thus allowing for a smaller and lighter overall wire drive mechanism. Furthermore, since there is only one pulley for changing the direction, friction between the first wire 3 and the second wire 4 can be reduced.

[0027] Incidentally, the reason why only one first changing pulley 14 is needed to change the direction of the first wire 3 is because the first changing pulley 14 is positioned according to the following concept. That is, as shown in Figure 3, the first wire 3 is wound along the first tangent 11a of the first driven pulley 11, and then wound along the first tangent 13a of the second rotating shaft drive pulley 13. Therefore, in order to smoothly guide the first wire 3 from the first driven pulley 11 to the second rotating shaft drive pulley 13, it is necessary to guide the first wire 3 from the first tangent 11a of the first driven pulley 11 to the first tangent 13a of the second rotating shaft drive pulley 13. To achieve this, in this embodiment, as shown in Figure 3, the first changing pulley 14 is positioned at the intersection of the first tangent 11a of the first driven pulley 11 and the first tangent 13a of the second rotating shaft drive pulley 13. In this way, the first changing pulley 14 can engage with both the first tangent 11a of the first driven pulley 11 and the first tangent 13a of the second rotating shaft drive pulley 13. Therefore, the first changing pulley 14 can not only change the direction of the first wire 3 that has been guided from the first tangent 11a of the first driven pulley 11, but also guide it to the first tangent 13a of the second rotating shaft drive pulley 13.

[0028] However, by arranging the first changing pulley 14 according to the above considerations, it becomes possible to change the direction of the first wire 3 by simply arranging one first changing pulley 14.

[0029] On the other hand, the reason why only one second changing pulley 15 is needed to change the direction of the second wire 4 is because the second changing pulley 15 is positioned according to the following concept. That is, as shown in Figure 3, the second wire 4 is wound along the second tangent 11b of the first driven pulley 11, and then wound along the second tangent 13b of the second rotating shaft drive pulley 13. Therefore, in order to smoothly guide the second wire 4 from the first driven pulley 11 to the second rotating shaft drive pulley 13, it is necessary to guide the second wire 4 from the second tangent 11b of the first driven pulley 11 to the second tangent 13b of the second rotating shaft drive pulley 13. To achieve this, in this embodiment, as shown in Figure 3, the second changing pulley 15 is positioned at the intersection of the second tangent 11b of the first driven pulley 11 and the second tangent 13b of the second rotating shaft drive pulley 13. In this way, the second changing pulley 15 can engage with both the second tangent 11b of the first driven pulley 11 and the second tangent 13b of the second rotating shaft drive pulley 13. Therefore, the second changing pulley 15 can not only change the direction of the second wire 4 that has been guided from the second tangent 11b of the first driven pulley 11, but also guide it to the second tangent 13b of the second rotating shaft drive pulley 13.

[0030] However, by arranging the second changing pulley 15 according to the above considerations, it becomes possible to change the direction of the second wire 4 by simply arranging one second changing pulley 15.

[0031] According to the embodiment described above, when changing the direction of the first wire 3, one first changing pulley 14 is provided, and when changing the direction of the second wire 4, one second changing pulley 15 is provided. Therefore, as in the conventional method, it is not necessary to provide multiple changing pulleys for the wire whose direction you want to change. In addition, since there is only one changing pulley, friction between the first wire 3 and the second wire 4 can be reduced.

[0032] However, according to this embodiment, it is possible to make the device smaller and lighter, and also to reduce wire friction.

[0033] The shapes and other features shown in this embodiment are merely examples, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. For example, although this embodiment uses two axes as an example, it is not limited to this, and can be applied to three or more axes using a similar approach. A concrete example can be shown in Figure 4. A detailed explanation will follow below. Note that the same reference numerals are used for components identical to those in Figures 2 and 3, and their descriptions will be omitted.

[0034] As shown in Figure 4, a second driven pulley 20 is positioned on the first rotating shaft Z1, which rotates in conjunction with the rotation of the first rotating shaft drive pulley 10. As shown in Figure 4, the third wire 22 and the fourth wire 23, which have been guided via the intermediate pulley 21, are wound around this second driven pulley 20.

[0035] On the other hand, as shown in Figure 4, a third driven pulley 24 is positioned on the second rotating shaft Z2, which rotates in conjunction with the rotation of the second rotating shaft drive pulley 13. The third wire 22 and the fourth wire 23, which are wound around the second driven pulley 20, are wound around this third driven pulley 24, as shown in Figure 4. More specifically, the direction of the third wire 22 is changed by a third changing pulley 25, which is positioned in the same manner as described above, and guided from the second driven pulley 20 to the third driven pulley 24. The direction of the fourth wire 23 is changed by a fourth changing pulley 26, which is positioned in the same manner as described above, and guided from the second driven pulley 20 to the third driven pulley 24. Thus, the third wire 22 and the fourth wire 23 are wound around the third driven pulley 24. Then, the third wire 22 and the fourth wire 23, which are wrapped around the third driven pulley 24, are guided to a third rotating shaft (not shown) via the intermediate pulley 27, as shown in Figure 4. In this way, it is possible to apply it to three or more axes. Furthermore, if it is possible to apply it to three or more axes in this way, it can be applied to robots with more joints, such as multi-legged robots and multi-jointed arm robots. [Explanation of symbols]

[0036] 3. First wire 4. Second wire 11. First driven pulley (first pulley) 11a 1st tangent 11b Second tangent 13. Second rotating shaft drive pulley (second pulley) 13a 1st tangent 13b Second tangent 14. First change pulley (first change pulley) 15. Second change pulley (second change pulley) Z1 First rotation axis Z2 Second rotation axis

Claims

[Claim 1] A single first pulley positioned on the first rotation axis, A single second pulley is positioned on a second rotation axis located in a direction intersecting the first rotation axis, A first wire wrapped around the first pulley and the second pulley, A second wire wrapped around the first pulley and the second pulley, The first wire and the second wire are wrapped around a drive pulley such that when one wire is pulled, the other wire is pushed out. The drive pulley is rotatably mounted, and the actuator pulls the first wire and the second wire in an antagonistic manner. When winding the first wire, which is wound around the first pulley, onto the second pulley, a single first changing pulley is used to guide the wire from the first tangential direction of the first pulley to the first tangential direction of the second pulley, The second wire, which is wound around the first pulley, is wound around the second pulley by a single second changing pulley which guides the wire from the second tangential direction of the first pulley to the second tangential direction of the second pulley. The first wire is wrapped around the outer surfaces of the first and second pulleys so as to cover only a portion of them, not all of them. The second wire is wrapped around the outer surfaces of the first and second pulleys so as to cover only a portion of them, not all of them. The first changing pulley is positioned where the first tangent of the first pulley and the first tangent of the second pulley intersect, and when the axial direction of the first pulley and the axial direction of the second pulley intersect in the vertical up-and-down direction, the axial direction of the first changing pulley is positioned toward the vertical up-and-down direction. The wire drive mechanism wherein the second changing pulley is positioned at the intersection of the second tangent of the first pulley and the second tangent of the second pulley, and when the axial direction of the first pulley and the axial direction of the second pulley are positioned at the intersection in the vertical direction, the axial direction of the second changing pulley is positioned at the intersection in the vertical direction.

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