Drive for a joint of a robot arm, a related robot arm and a corresponding rotary lead-through

Abstract

A drive mechanism for a joint of a robotic arm includes: a drive member connected to a guide tube end section of a cable guide tube, having a hub section connected to the guide tube end section, a radially outwardly offset cable guide section, and a connecting section connecting the two; an annular space coaxially arranged with a motor for accommodating a cable loop placed in the annular space, the annular space having an opening through which the cable can be fed into the annular space; the cable guide section of the drive member is designed such that, in the inserted state, the cable is axially guided from the tube end on the transmission mechanism side to the tube end on the motor side through the cable guide tube and radially guided to the cable guide section; the cable is brought into the opening of the annular space in a transition section when the transmission mechanism output member rotates, such that the cable is introduced into the annular space at a circumferential position corresponding to the instantaneous rotational position of the transmission mechanism output member. A related robotic arm and a corresponding rotary guide member are also disclosed.

Description

Technical Field

[0001] This invention relates to a drive mechanism for a joint of a robotic arm, comprising: a motor having a motor housing and a hollow motor shaft rotatably mounted within the motor housing; a transmission mechanism coaxially arranged with the motor shaft, the transmission mechanism having a hollow transmission mechanism input member coupled to the motor shaft, a hollow transmission mechanism output member, and a support member coupling the transmission mechanism input member and the transmission mechanism output member; and a cable guide tube connected to the transmission mechanism output member, the cable guide tube extending axially from its end on the transmission mechanism side through the hollow motor shaft from the transmission mechanism output member, extending to its rear end on the motor housing, axially opposite to the transmission mechanism, and forming a guide tube end section thereon. The invention also relates to a related robotic arm and a corresponding rotary guide (Drehdurchführung). Background Technology

[0002] Patent document CN107718036A describes a hollow integrated dual-feedback transmission mechanism, including a frameless motor, a brake, an incremental encoder, an absolute encoder, a high-speed motor shaft, a low-speed hollow shaft, a driven flange, motor shaft bearings and hollow shaft bearings, a driver, a housing, a first bearing housing, a second bearing housing, a third bearing housing, and connecting cables and a transition shaft. The motor rotor, incremental encoder, and brake are mounted on the high-speed motor shaft, and the absolute encoder is mounted on the low-speed hollow shaft. High control accuracy is achieved due to the dual feedback on a compact, high-precision hollow joint, which is designed to be hollow for easy wiring. Summary of the Invention

[0003] The object of this invention is to provide a drive device having a hollow motor shaft and a hollow transmission mechanism output member, wherein the cable to be guided through the hollow motor shaft and the hollow transmission mechanism output member can be wired in a particularly abrasion-resistant manner. Another object of this invention is to provide a robot arm having at least one corresponding drive device and / or a corresponding rotary guide for at least one joint of the robot arm.

[0004] The objective of this invention is achieved by a drive mechanism for a joint of a robotic arm, the drive mechanism comprising: - A motor having a motor housing and a hollow motor shaft rotatably mounted within the motor housing. - A transmission mechanism, arranged coaxially with the motor shaft, having a hollow transmission mechanism input member coupled to the motor shaft, a hollow transmission mechanism output member, and a support member coupling the transmission mechanism input member and the transmission mechanism output member. - A cable guide tube, connected to the output component of the transmission mechanism, extends axially from its transmission mechanism side end through the hollow motor shaft, starting from the output component, and extends to its rear end on the motor housing, opposite to the transmission mechanism, where it forms the guide tube end section. - A drive member connected to the guide tube end section of a cable guide tube, the drive member having a hub section connected to the guide tube end section, a radially outwardly offset cable guide section, and a connecting section connecting the hub section and the cable guide section. - An annular space arranged coaxially with the motor, the annular space being designed to accommodate a cable loop placed in the annular space, wherein the annular space has an opening through which the cable can be fed into the annular space, wherein the cable guide section of the drive member is designed such that, in the cable insertion state, the cable is axially guided from the tube end on the transmission mechanism side to the tube end on the rear side of the motor through the cable guide tube and radially guided to the cable guide section, and when the output member of the transmission mechanism rotates, the cable is brought into the opening of the annular space in the cable transition section, so that the cable is introduced into the annular space at the circumferential position (Umfangsstelle) corresponding to the instantaneous rotation position (momentanen Drehstellung) of the output member of the transmission mechanism.

[0005] A drive device with a hollow motor shaft and a hollow transmission mechanism output component is provided, enabling the cable to be guided through the hollow motor shaft and the hollow transmission mechanism output component, which is particularly suitable for robotic arms. Thus, the cable can be arranged inside the robotic arm, eliminating the need for external cable routing, which is detrimental to the robotic arm's profile.

[0006] The cable can be a single cable or comprise multiple individual conductors, which may be combined into a bundle, for example. If it is now specified that the cable should be guided through a hollow motor shaft, especially in the case of a robot arm where the cable should be guided from one segment of the robot arm to an immediately adjacent segment, the torsional stress acting on the cable may be detrimental, and in particular, may shorten the cable's lifespan, as excessive torsional stress may cause undesirable conductor breakage.

[0007] While cable manufacturers take into account certain torsional stresses and allow them to act within predetermined limits without causing harmful conductor breakage within the cable's intended lifespan, they also specify, for example, minimum cable section lengths that must be adhered to, which are only permitted to withstand limited torsional angles.

[0008] However, especially in robotic arms, where structural space is limited, the cables guided through the hollow motor shaft must, to some extent, compensate for the torsion caused by the relative rotational motion of two directly adjacent segments of the robotic arm's rotary joint. One limiting aspect is that the entire cross-section of the hollow motor shaft cannot be occupied by the cable; instead, a certain amount of free space must be reserved so that the cable can radially avoid torsion stress, thereby reducing torsion stress. To this end, cable manufacturers also specify a maximum fill power, which determines the ratio of the cross-sectional area occupied by the cable to the unoccupied cross-sectional area within the hollow motor shaft.

[0009] Transmission mechanisms, especially those in robot arms, are typically designed with speed reduction, which causes the motor shaft connected to the input member of the transmission mechanism to rotate faster than a hollow input member.

[0010] Therefore, in the drive device according to the invention, the cable guide tube is connected to the output member of the hollow transmission mechanism, resulting in a slower rotational speed for the cable guide tube. Since, particularly in the case of a robot arm, the output member of the transmission mechanism is connected to a segment of the robot arm, the output member of the transmission mechanism does not rotate relative to that segment of the robot arm. Therefore, for example, the cable fixed to that segment will not move relative to that segment of the robot arm.

[0011] To ensure that the cable experiences no torsional stress and, in particular, no torsional movement along its length within the cable guide tube, the cable guide tube is now fully guided through the hollow motor shaft until it reaches the end of the drive unit opposite the output member of the transmission mechanism, where the cable is drawn out of the cable guide tube and subsequently radially dispersed. For this purpose, a drive element is provided at the guide tube end section, guiding the cable in its radial section and in the cable guiding section of the drive element, such that the cable rotates synchronously with the rotation of the output member of the transmission mechanism and thus synchronously with the cable guide tube in its radial section, thereby preventing cable torsion; that is, no cable torsion occurs because the cable always rotates in the same manner with the output member of the transmission mechanism and the cable guide tube.

[0012] In the drive device according to the invention, the adaptation of one cable end to another cable end, or the adaptation of the relative torsional movement of the transmission mechanism output member to the motor housing or a component connected to the motor housing, is arranged in an annular space in which the cable does not at least substantially twist, but only performs bending motion or bears bending stress along the cable loop.

[0013] The annular space extends coaxially with the motor housing. Cable sections extending from the annular space on the other side of the drive component can be correspondingly fixed to the motor housing or to components connected to the motor housing, particularly to robot arm segments connected to the motor housing and adjacent to the rotary joint.

[0014] The drive component is fixedly connected to the cable guide tube, enabling it to perform the same rotational motion as the cable guide tube and the output component of the transmission mechanism connected to it. In this respect, no relative movement that would cause wear occurs between the cable and the inner wall of the cable guide tube. This also has a further advantage: it allows for increased filling density in the cable guide tube, enabling the guidance of thicker cables or cable bundles with larger diameters through the hollow motor shaft.

[0015] The annular space may have an inner wall that circumferentially surrounds the motor housing and an outer wall that circumferentially surrounds the inner wall of the annular space and is arranged radially spaced from it. A storage space (Lagerraum) for guiding a cable loop through the annular space is formed between the inner wall and the outer wall of the annular space, and the opening of the annular space is located on the same circumference as the cable guiding section of the drive component.

[0016] The inner wall of the annular space radially supports the cable loop extending within it, into which the cable has been inserted. The outer wall of the annular space radially supports the cable loop extending within it. In this respect, the storage space is a cylindrical annular space. The annular space may have an opening on at least one of its two ends, through which a cable transition section guided by a drive element is introduced into the annular space. In this respect, the opening may be annular. The opening may extend coaxially around the motor housing. The opening may have a radial opening width that is only slightly larger than the diameter of the cable.

[0017] The annular space or storage space for the cable loop can thus form a cable reel. This cable reel does not necessarily need to be located at the same axial height as the motor of the drive unit. Therefore, the annular space can also be arranged offset relative to the motor axis.

[0018] However, it may be particularly advantageous to arrange the annular space at the same axial height as the motor in drive units where the motor diameter is significantly smaller than that of the transmission mechanism, and thus the transmission mechanism diameter is significantly larger than that of the motor. In this respect, the annular space can surround the motor circumferentially. The annular space or storage space for the cable loop can particularly have a radial structural height less than half the difference between the motor diameter and the transmission mechanism diameter. Therefore, the annular space or storage space for the cable loop can have a diameter at least slightly smaller than the outer diameter of the transmission mechanism. Thus, despite the additional annular space provided for the cable loop, a particularly compact structure of the drive unit can still be achieved.

[0019] The connecting section of the drive component can be formed by a lever that extends radially from the hub section to the cable guide section.

[0020] Therefore, the drive component does not necessarily have to be designed as a disc. The connecting section can therefore be designed as a rod, and in its basic shape, functionally provide only a rigid connection from the hub section to the cable guide section, so that the rotational position of the hub section is precisely transmitted to the rotational position of the cable guide section. However, in addition to functioning as a lever connecting the hub section and the cable guide section, the connecting section can also have additional functions.

[0021] As an alternative to levers, the connecting section of the drive component can be formed by an annular disc or annular disc sector extending radially from the hub section to the cable guide section.

[0022] If the drive element is designed as a ring-shaped disc, this disc covers the rear end face of the motor or the entire drive unit, and thus can additionally serve as a protective cover, for example, to prevent dust and accidental intrusion into the drive unit. Furthermore, the inner wall of the ring-shaped disc facing the motor can form a lateral guide surface for the cable loop in the ring-shaped space. In this respect, the ring-shaped disc largely and completely covers the opening in the ring-shaped space except for the cable guide section area.

[0023] When the drive component is designed as an annular disc segment, the inner wall of the annular disc segment facing the motor can also form a lateral guide surface for the cable loop in the annular space. The angle of the annular disc segment can be adapted to the maximum rotational angle difference between the motor housing and the input component of the transmission mechanism.

[0024] The drive element can be designed, in particular, to be can-shaped, wherein the connecting section designed as an annular disk is formed by the bottom surface of the can-shaped drive element, and at least one side surface of the can-shaped drive element axially forms at least partially or completely the outer wall and / or inner wall of the annular space.

[0025] In this variation, the drive component thus also forms part of the annular space, i.e., part of the outer wall and / or inner wall of the annular space. The can-shaped drive component's can side can extend, in particular, across half the axial width of the annular space. Accordingly, the half of the cable loop facing the drive component can be covered or enclosed (eingeschlossen) between the two coaxially spaced can sides of the can-shaped drive component. The inner wall of the annular space formed by the inner can side is mounted relative to the motor housing with at least a small gap. Therefore, the inner wall of the annular space formed by the inner can side can perform relative movement relative to the motor housing. In this variation, the inner can side is not also part of the motor housing.

[0026] The inner wall of the connecting section of the drive component, which is designed as an annular disk or an annular disk sector, facing the annular space, can form an axial annular end wall of the annular space or a circumferential sub-segment of the axial annular end wall of the annular space. The cable loop formed in the annular space is axially guided on the axial annular end wall or circumferential sub-segment.

[0027] In this regard, the inner wall prevents the cable loop from detaching from the annular space. Due to the bending stress in the bending section of the cable loop, there is a tendency for the sides of the cable loop to be axially extruded outwards. This extrusion tendency is prevented by the inner wall of the drive component connection section.

[0028] The cable guiding section may have radially oriented guide walls that lead in the direction of rotation of the drive member and radially oriented guide walls that lag in the direction of rotation of the drive member, wherein the two guide walls are arranged spaced apart from each other, so that the inserted cable is guided from two opposite sides.

[0029] Therefore, the cable guiding section can be formed by an open notch in the drive element, particularly in drive elements designed as annular discs or annular disc segments. This notch can have an axial clearance width that matches the diameter of the cable to be guided. Therefore, the axial clearance width of the notch can be slightly larger than the diameter of the cable to be guided. Here, a certain amount of play between the notch and the inserted cable is harmless.

[0030] Each of these two guide walls serves as the edge of the driving element according to the direction of rotation, so that it rotates together with the driven component of the transmission mechanism or the guide tube according to the rotational angular position, i.e., the guide cable. If necessary, the radial section of the cable can be fixed to the outer wall of the driving element.

[0031] The drive unit may have a cable placed in a cable guide tube, which is fastened to the transmission input member or to a component connected to the transmission input member, and the cable is axially guided out of the cable guide tube at the rear end of the motor and guided radially to the cable guide section, where the cable enters the annular space and forms a cable loop therein.

[0032] A drive unit can also be a device without cables, for example, manufactured and supplied as a spare part or accessory. However, a drive unit can also be designed as a kit, in which the drive unit is already equipped with cables. For example, for multiple drive units to be mounted in a robot arm, each of the multiple drive units can have a cable segment, which can be provided with an electrical plug, socket, or coupling at both ends of the cable, for example. Each drive unit can then be assembled with its associated cable segment, and the multiple cable segments are then electrically connected by their electrical plugs, sockets, or couplings. However, alternatively, it can be specified that a single cable or a single cable bundle passes through multiple drive units.

[0033] The object of the present invention is also achieved by a robotic arm having a plurality of segments and joints that adjustably connect these segments to each other, wherein at least one joint has a drive mechanism according to one of the foregoing embodiments.

[0034] The joint of the robot arm having a drive device according to one of the foregoing embodiments may have a hollow first segment and a second segment directly rotatably connected to the hollow first segment. In the robot arm, a motor housing may be arranged inside the hollow first segment, and an intermediate space may be formed between the outer side of the motor housing and the inner side of the hollow first segment, wherein the annular space is arranged in the intermediate space.

[0035] The cable placed in the cable guide tube can be fixed to the second segment connected to the output component of the transmission mechanism.

[0036] The technical teachings of the present invention are not limited to drive mechanisms, but can also be implemented in non-drive joints, more specifically in the form of a rotary guide, which, for example, guides a cable through a hinge region. In this hinge region, the first component or first segment also rotates relative to the second component or second segment. A similar task arises when guiding the cable axially through the hollow journal and the hollow rotary journal housing: preventing cable twisting.

[0037] Therefore, the object of the present invention is also achieved by a rotary guide for a joint of a robot arm, the rotary guide comprising: - Hollow rotating journal housing, - A hollow rotating journal, coaxially and rotatably mounted in a hollow rotating journal housing. - A cable guide tube connected to a hollow rotating journal, the cable guide tube extending axially from its end on the base side of the journal through the hollow rotating journal, to its end on the head side of the journal, opposite to the base of the journal, where a guide tube end section is formed. - A drive member connected to the guide tube end section of a cable guide tube, the drive member having a hub section connected to the guide tube end section, a radially outwardly offset cable guide section, and a connecting section connecting the hub section and the cable guide section. - An annular space coaxially arranged with the hollow rotating journal receiving portion, the annular space being designed to accommodate a cable loop placed in the annular space, wherein the annular space has an opening through which the cable can be fed into the annular space, wherein the cable guiding section of the drive member is designed such that, in the cable insertion state, the cable is axially guided from the tube end on the journal base side to the tube end on the journal head side through the cable guiding tube and radially guided to the cable guiding section, and when the hollow rotating journal rotates relative to the hollow rotating journal receiving portion, the cable is brought into the opening of the annular space in the cable transition section, such that the cable is introduced into the annular space at a circumferential position corresponding to the instantaneous rotation position of the hollow rotating journal relative to the hollow rotating journal receiving portion.

[0038] The features described in the drive unit, particularly those concerning the cable guide tube, the drive element, and the annular space, can be similarly applied to rotary threading components. Accordingly, the corresponding disclosure of the drive unit also applies to rotary threading components. Attached Figure Description

[0039] Specific embodiments of the invention will now be described in detail with reference to the accompanying drawings. Specific features of these exemplary embodiments may be considered individually or in combination as necessary to represent advantageous features of alternative embodiments of the invention, regardless of where they are specifically mentioned herein.

[0040] Figure 1 A perspective view of a representative embodiment of a robot is shown, particularly a lightweight robot designed for human-robot collaboration. The robot includes: a robotic arm having articulated limbs, joints, and actuation devices; and a control device configured and designed to automatically manipulate the actuation devices to move the robotic arm.

[0041] Figure 2 A partial perspective view of a modified robotic arm in the joint region of the robotic arm, the joint including a drive mechanism, is shown.

[0042] Figure 3 A perspective cross-sectional view of an exemplary embodiment of the drive device according to the present invention is shown.

[0043] Figure 4 It shows Figure 3 The axial cross-sectional view shown is an exemplary embodiment of the drive device according to the invention, which has a can-shaped drive member in a first variant embodiment, the drive member having only one outer can side.

[0044] Figure 5 It shows Figure 3 The axial cross-sectional view shown is an exemplary embodiment of the drive device according to the invention, which has a can-shaped drive member in a second variant embodiment, the drive member having an outer can side and an inner can side.

[0045] Figure 6 Showing what is seen from the outside, according to Figure 3 A perspective view of the drive unit, showing an annular outer wall surrounding the motor and a disc-shaped drive component.

[0046] Figure 7 It shows that according to Figure 6 The perspective view of the drive unit when the outer wall of the annular space is removed allows the cable loop installed in the annular space to be seen.

[0047] Figure 8 It shows that according to Figure 6 A perspective view of the drive device, which has a semi-circular drive member in the first variant embodiment, which is a modification of the disc-shaped drive member.

[0048] Figure 9 It shows that according to Figure 6 A perspective view of the drive device, which has a lever-type drive element in a second variant embodiment, modified from the disc-shaped and semi-circular drive elements. Detailed Implementation

[0049] Figure 1 The image shows a robotic arm 3 having a plurality of limbs G and joints L that adjustably connect the limbs G to each other, wherein at least one joint L may have a drive device 4 according to the invention.

[0050] Figure 1A robotic arm 3 in the form of a lightweight robot 3a is shown, having a total of six or seven axes. The lightweight robot 3a is particularly suitable for human-robot collaboration. The lightweight robot 3a can be operated in a force / torque-adjustable manner via a control device 2, particularly in a flexible adjustment manner. The lightweight robot 3a has multiple limbs G and joints L that adjust the limbs G relative to each other, wherein all joints L are designed as rotary joints. In this regard, the respective joints L respectively rotatably connect the first limb G1 of the robotic arm 3 to the directly adjacent second limb G2 relative to each other, wherein the respective rotary joints may have a drive device 4 according to the invention, as described in one of the foregoing embodiments.

[0051] In a robotic arm 3 having multiple limbs G and multiple joints L, each joint L connects two directly adjacent limbs G in the kinetic chain of the robotic arm 3 in an adjustable manner via an automatically controllable drive device 4, wherein each drive device is designed to move one joint in the joint L, such that the limbs G of the robotic arm 3 can be adjusted to a desired joint configuration by automatically controlling the movement of the joint L by means of the respective drive device 4.

[0052] At least one drive device 4, particularly multiple or all drive devices 4 of joint L, can be designed as a drive device 4 according to one of the embodiments described in the present invention.

[0053] Figure 2 A partial section of the robot arm 3 is shown, the section having a plurality of limbs G and a plurality of joints L that adjustably connect the limbs G to each other, wherein at least one joint L is designed as a rotary joint having a drive device 4 according to one of the embodiments.

[0054] Optionally, all joints of the robotic arm 3 may be equipped with a drive device 4 according to one of the embodiments, or only a portion of the joints L may be equipped with a drive device 4 according to one of the embodiments. In a simple embodiment, the robotic arm 3 may also have only one joint L equipped with a drive device 4 according to one of the embodiments, while the remaining joints L of the robotic arm 3 may be equipped with conventional drive devices.

[0055] The joint L of the robot arm 3, having a drive device 4 according to one of the embodiments, may have a hollow first segment G1 and a second segment G2 directly rotatably connected to the hollow first segment G1. The motor housing 6 of the drive device 4 may be at least partially or completely arranged inside the hollow first segment G1, and a hollow space Z is formed between the outer side of the motor housing 6 and the inner side of the hollow first segment G1. An annular space R is arranged in this hollow space, such as... Figure 3 As shown.

[0056] The inserted cable 7 can be fixed, for example, to the second segment G2 connected to the transmission mechanism output member 15 of the drive unit 4.

[0057] exist Figures 3 to 9 An exemplary drive device 4 for one of the joints L of a robot arm 3, shown in the figure, has a motor 9 having a motor housing 6 and a hollow motor shaft 10 rotatably mounted in the motor housing 6. The motor 9 may have a stator 11 connected to the motor housing 6 and a rotor 12 running in the stator. The rotor 12 is connected to the hollow motor shaft 10.

[0058] The drive unit 4 also has a transmission mechanism 13 arranged coaxially with the motor shaft 10. The transmission mechanism has a hollow transmission mechanism input member 14 coupled to the motor shaft 10, a hollow transmission mechanism output member 15, and a support member 16 that couples the transmission mechanism input member 14 and the transmission mechanism output member 15.

[0059] Especially as Figure 3 As shown, in this embodiment, the transmission mechanism 13 is designed as a harmonic transmission mechanism.

[0060] In this harmonic drive mechanism, the wave generator forms the input component 14 of the drive-side drive mechanism, while the driven sleeve (flexible wheel) forms the output component 15 of the driven-side drive mechanism. Here, the inner toothed outer ring (circular spline) of the harmonic drive mechanism forms a support component 16, which is connected to the motor housing 6.

[0061] In addition, the drive unit 4 also includes a cable guide tube 17 connected to the transmission mechanism output member 15. The cable guide tube starts from its transmission mechanism side tube end 17a, passes axially through the hollow motor shaft 10 from the transmission mechanism output member 15, and extends to its rear motor side tube end 17b located on the motor housing 6 and axially opposite to the transmission mechanism 13, where a guide tube end section 18 is formed.

[0062] The drive unit 4 has a drive member 19 connected to the guide tube end section 18 of the cable guide tube 17. The drive member has a hub section 19a connected to the guide tube end section 18, a radially outwardly offset cable guide section 19b, and a connecting section 19c connecting the hub section 19a and the cable guide section 19b.

[0063] Furthermore, the drive unit 4 also has an annular space R arranged coaxially with the motor 9. This annular space is designed to accommodate a cable loop 7a of the cable 7 placed within the annular space R, which is particularly as follows: Figure 7 As shown. The annular space R has an opening 20 ( Figure 6The cable 7 can be fed into the annular space R through the opening. The cable guide section 19b of the drive member 19 is designed such that, when the cable 7 is inserted, the cable 7 is axially guided from the transmission mechanism side tube end 17a to the motor rear tube end 17b through the cable guide tube 17, and is radially guided to the cable guide section 19b via the cable radial section 7b. When the transmission mechanism output member 15 rotates, the cable 7 is brought into the opening 20 of the annular space R in the cable 7 transition section 7c, so that the cable 7 is introduced into the annular space R at the circumferential position corresponding to the instantaneous rotation position of the transmission mechanism output member 15.

[0064] The annular space R has an inner annular space wall 21 that circumferentially surrounds the motor housing 6 and an outer annular space wall 22 that circumferentially surrounds the inner annular space wall 21 and is arranged radially at a distance A from the inner annular space wall 21. A storage space for a cable loop 7a for guiding the cable 7 through the annular space R is formed between the inner annular space wall 21 and the outer annular space wall 22. The opening 20 of the annular space R is located on the same circumference as the cable guiding section 19b of the drive member 19.

[0065] According to such Figure 6 and Figure 7 In the basic embodiment shown, the connecting section 19c of the drive member 19 can be formed by an annular disk that extends radially from the hub section 19a to the cable guide section 19b.

[0066] Alternatively, the drive component 19 can also be designed as a canister, such as... Figure 4 As shown in the cross-sectional view, the connecting section 19c, which is designed as an annular disk, is formed by the bottom surface 23 of the can-shaped drive member 19, while the side surface 24 of the can-shaped drive member 19 axially, at least partially or completely, forms the annular outer wall 22 of the annular space R.

[0067] In another variation, such as Figure 5 As shown in the cross-sectional view, the can-shaped drive 19 may have two can sides, more specifically an outer can side 24 and an inner can side 28.

[0068] Accordingly, half of the cable loop 7a facing the drive member 19 can be enclosed between two coaxially spaced can sides 24 and 28 of the can-shaped drive member 19. The inner wall 21a of the annular space formed by the inner can side 28 is mounted relative to the motor housing 6 with at least a small gap. Therefore, the inner wall 21a of the annular space formed by the inner can side 28 can perform relative movement relative to the motor housing 6. Therefore, according to... Figure 5 In a modified embodiment, the inner tank side 28 is also not part of the motor housing 6. According to... Figure 5In the variant, the annular space R does not completely surround the motor housing 6, but is arranged partially axially outward about the rear end of the motor housing 6. Alternatively, the cable ring 7c does not axially enter the annular space R at the end, but passes radially from below through the inner tank side 28.

[0069] exist Figure 7 The diagram shows how the inner wall 5 of the connecting section 19c of the drive 19, which is designed as a ring disk, facing the annular space R can form an axial annular end wall of the annular space R, on which the cable loop 7a formed by the cable 7 in the annular space R can be axially guided, i.e., in the direction of arrow P1.

[0070] The cable guiding section 19b has a radially oriented guide wall 25 that leads the rotation direction P2 of the drive member 19 and a radially oriented guide wall 26 that lags behind the rotation direction P2 of the drive member 19, wherein the two guide walls 25, 26 are arranged spaced apart from each other, so that the inserted cable 7 is guided from two opposite sides.

[0071] Figures 3 to 9 The drive unit 4 is shown, which has a cable 7 inserted into a cable guide tube 17. This cable is secured to a transmission mechanism output member 15 or to a segment 8 connected to the transmission mechanism output member 15. The cable 7 is axially led out of the cable guide tube 17 at a tube end 17b on the rear side of the motor and radially led as a cable radial segment 7b to a cable guide segment 19b, where the cable enters an annular space R in its transition segment 7c and forms a cable loop 7a therein, as is particularly evident in… Figure 7 As clearly shown in the text.

[0072] Figure 8 It shows that according to Figure 6 A perspective view of the drive unit 4, which has a first variant of the drive unit 19, a semi-circular drive unit 19, which is a variation of the disc-shaped drive unit 19. In this first variant, the connecting section 19c of the drive unit 19 is formed by an annular disk sector extending radially from the hub section 19a to the cable guide section 19b, having a sector angle of, for example, 180 degrees. However, other sector angles, such as 90 degrees or 270 degrees, or other angle values ​​in between, can also be considered and implemented.

[0073] Figure 9 It shows that according to Figure 6 A perspective view of the drive device, which has a second variant embodiment with a lever 27 in the form of a drive member 19, which is a variation of the disc-shaped and semi-circular drive member 19.

[0074] In this second variant embodiment, the connecting section 19c of the drive member 19 is formed by a lever 27 that extends radially from the hub section 19a to the cable guide section 19b.

Claims

1. A drive device (4) for a joint (L) of a robot arm (3), comprising: - Motor (9), having a motor housing (6) and a hollow motor shaft (10) rotatably mounted in the motor housing (6). - A transmission mechanism (13) arranged coaxially with the motor shaft (10), the transmission mechanism having a hollow transmission mechanism input member (14) coupled to the motor shaft (10), a hollow transmission mechanism output member (15) and a support member (16) coupling the transmission mechanism input member (14) and the transmission mechanism output member (15). - A cable guide tube (17) connected to the output member (15) of the transmission mechanism, the cable guide tube starting from its end (17a) on the transmission mechanism side, axially passing through the hollow motor shaft (10) from the output member (15) of the transmission mechanism, and extending to its end (17b) on the rear side of the motor located on the motor housing (6) opposite to the transmission mechanism (13), and forming a guide tube end section (18) there. - A drive member (19) connected to the guide tube end section (18) of the cable guide tube (17), the drive member having a hub section (19a) connected to the guide tube end section (18), a radially outwardly offset cable guide section (19b), and a connecting section (19c) connecting the hub section (19a) and the cable guide section (19b). - An annular space (R) coaxially arranged with the motor (9), the annular space being designed to accommodate a cable loop (7a) of a cable (7) placed in the annular space (R), wherein the annular space (R) has an opening (20) through which the cable (7) can be fed into the annular space (R), wherein the cable guide section (19b) of the drive member (19) is designed such that, in the inserted state of the cable (7), the cable (7) is axially guided from the tube end (17a) on the transmission mechanism side to the tube end (17b) on the rear side of the motor through the cable guide tube (17) and radially guided to the cable guide section (19b), and the cable (7) is brought into the opening (20) of the annular space (R) in the transition section (7c) of the cable (7) when the transmission mechanism output member (15) rotates, such that the cable (7) is introduced into the annular space (R) at a circumferential position corresponding to the instantaneous rotational position of the transmission mechanism output member (15).

2. The driving device (4) according to claim 1, characterized in that, The annular space (R) has an annular inner wall (21) that circumferentially surrounds the motor housing (6) and an annular outer wall (22) that circumferentially surrounds the annular inner wall (21) and is arranged radially at a distance (A) from the annular inner wall (21). A storage space for a cable loop (7a) for guiding a cable (7) through the annular space (R) is formed between the annular inner wall (21) and the annular outer wall (22). The opening (20) of the annular space (R) is located on the same circumference as the cable guiding section (19b) of the drive member (19).

3. The driving device (4) according to claim 1 or 2, characterized in that, The connecting section (19c) of the drive member (19) is formed by a lever (27) that extends radially from the hub section (19a) to the cable guide section (19b).

4. The driving device (4) according to claim 1 or 2, characterized in that, The connecting section (19c) of the drive member (19) is formed by an annular disc or annular disc sector extending radially from the hub section (19a) to the cable guide section (19b).

5. The driving device (4) according to claim 4, characterized in that, The drive member (19) is designed as a can, wherein the connecting section (19c) designed as an annular disk is formed by the bottom surface (23) of the can of the can-shaped drive member (19), and at least one side surface (24) of the can-shaped drive member (19) axially, at least partially or completely forms the outer wall (22) and / or the inner wall (21) of the annular space (R).

6. The driving device (4) according to claim 4 or 5, characterized in that, The inner wall (5) of the connecting section (19c) of the drive member (19), which is designed as an annular disk, facing the annular space (R), forms the axial annular end wall of the annular space (R), and the cable loop (7c) formed in the annular space (R) is axially guided on the axial annular end wall.

7. The driving device (4) according to any one of claims 1 to 6, characterized in that, The cable guiding section (19b) has a radially oriented guide wall (25) that leads in the rotation direction (P2) of the drive member (19) and a radially oriented guide wall (26) that lags in the rotation direction (P2) of the drive member (19), wherein the leading guide wall (25) and the lagging guide wall (26) are arranged spaced apart from each other, such that the inserted cable (7) is guided from two opposite sides.

8. The drive device (4) according to any one of claims 1 to 7, comprising a cable (7) placed in the cable guide tube (17), the cable being fastened to the transmission mechanism output member (15) or to a component (8) connected to the transmission mechanism output member (15), and the cable being axially led out of the cable guide tube (17) at a tube end (17b) on the rear side of the motor and guided in the radial direction to the cable guide section (19b), where the cable enters the annular space (R) and forms a cable loop (7c) therein.

9. A robotic arm (3) having a plurality of limbs (G) and joints (L) that adjustably connect the limbs (G) to each other, wherein at least one of the joints (L) has a drive device (4) according to any one of claims 1 to 8.

10. The robotic arm (3) according to claim 9, characterized in that, The joint (L) of the robot arm (3) having a drive device (4) according to any one of claims 1 to 8 has a hollow first segment (G1) and a second segment (G2) directly rotatably connected to the hollow first segment (G1), wherein the motor housing (6) is arranged inside the hollow first segment (G1) and an intermediate space is formed between the outer side of the motor housing (6) and the inner side of the hollow first segment (G1), and the annular space (R) is arranged in the intermediate space.

11. The robotic arm (3) according to claim 10, characterized in that, The cable (7) placed in the cable guide tube (17) is fixed on the second segment (G2) connected to the output member (15) of the transmission mechanism.

12. A rotary guide for a joint (L) of a robot arm (3), comprising: - Hollow rotating journal housing, - A hollow rotating journal is coaxially and rotatably mounted in the hollow rotating journal receiving portion. - A cable guide tube (17) connected to the hollow rotating journal, the cable guide tube extending axially from the tube end on the base side of the journal through the hollow rotating journal, and extending to the tube end on the head side of the journal located on the hollow rotating journal receiving portion, which is axially opposite to the base of the journal, and forming a guide tube end section (18) there. - A drive member (19) connected to the guide tube end section (18) of the cable guide tube (17), the drive member having a hub section (19a) connected to the guide tube end section (18), a radially outwardly offset cable guide section (19b), and a connecting section (19c) connecting the hub section (19a) and the cable guide section (19b). - An annular space (R) is arranged coaxially with the hollow rotating journal receiving portion. The annular space is designed to accommodate a cable loop (7c) of a cable (7) placed in the annular space (R). The annular space (R) has an opening (20) through which the cable (7) can be fed into the annular space (R). The cable guide section (19b) of the drive member (19) is designed such that, in the inserted state of the cable (7), the cable (7) is axially guided from the tube end on the journal base side to the tube end on the journal head side through the cable guide tube (17) and radially guided to the cable guide section (19b). When the hollow rotating journal rotates, the cable (7) is brought into the opening (20) of the annular space (R) in the transition section (7c) of the cable (7), so that the cable (7) is introduced into the annular space (R) at a circumferential position corresponding to the instantaneous rotational position of the hollow rotating journal relative to the hollow rotating journal receiving portion.

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