ROBOT ARM WITH A CABLE GUIDE DEVICE

Description

[0001] The invention relates to a robot arm according to the preamble of claim 1.

[0002] JP H02 237793 A describes such a robot arm in which detectors are attached to a support shaft via the cable drum, so that they rotate with one of the support shafts of a tilting part mounted at both ends. Associated detection elements are moved upon corresponding rotation of the tilting part, activating the detectors and thereby detecting the specific rotational position of the tilting part.

[0003] WO 2018 / 195969 A1 describes a cable harness guide module for a robot joint and a robot with at least one robot joint, which has such a cable harness guide module. The cable harness guide module comprises a base plate and a rotatable element that mates with the base plate and can rotate relative to the base plate. At least the base plate and the rotatable element form a device for receiving the cable harness, which has a first end and a second end. The cable harness guide module further comprises a first fastening element for fastening the first end to the base plate and a second fastening element for fastening the second end to the rotatable element.

[0004] DE 10 2017 213033 A1 describes an examination and / or treatment device comprising a multi-axis robot with an articulated arm movable in space and lines accommodated in a flexible sheathing tube and guided to one or more examination or treatment devices arranged on the articulated arm or a support arranged on the latter, wherein a carriage arrangement comprising a carriage having at least one deflection roller and linearly displaceable against at least one restoring element building up a restoring force is provided on the articulated arm, wherein the sheathing tube or a guide tube surrounding it is guided around the deflection roller

[0005] WO 2016 / 188797 A1 describes another robot arm with an energy cable guide.

[0006] The object of the invention is to provide a particularly simple to manufacture and reliable cable guide device on a robot arm, by means of which an intermediate strand section of a power cable strand can be guided particularly gently over a joint of the robot arm from a first structural part to a second structural part.

[0007] This object is achieved according to the invention by a robot arm according to claim 1.

[0008] The robot can be a so-called articulated-arm robot, the robot arm of which has a base frame as one link, on which a carousel as the following link is mounted so as to be rotatable about a vertical axis and is rotationally driven by a first drive motor. A swing arm as a further link can be mounted on the carousel so as to be pivotable up and down about a second horizontal axis and rotationally driven by a second drive motor. The swing arm carries an arm boom which is mounted so as to be pivotable up and down about a third horizontal axis and rotationally driven by a third drive motor. A fourth axis can be provided on the arm boom, the base arm of which forms a further link. This fourth axis runs in the longitudinal extension of the arm boom and a robot hand, which forms a front arm of the arm boom and represents a further link, is rotationally driven via a fourth drive motor.In a first variant of the robot hand, a first leg and a second leg can extend forward in a fork-like manner from the robot hand. In this first variant, the two legs carry a bearing for a free end of the robot hand, which is arranged between the two legs and forms a penultimate link. The bearing defines a fifth axis of the robot arm, about which the robot hand can be pivoted by means of a fifth drive motor. As an alternative to a robot hand with two legs, in a second variant the robot hand can have only a single leg, on which the bearing for the free end of the robot hand is then formed exclusively on this one leg, so that the free end is only mounted on one side of the single leg in the manner of a single-arm swing arm.In addition, the robot hand has a sixth axis to enable a mounting flange, which forms a final link, to be driven in a rotating manner by means of a sixth drive motor.

[0009] Each of the joints can be designed as a rotary joint. Each link is designed to transmit forces and moments, which are introduced in particular by a gripper or tool that is handled, in particular moved, by the robot, via a tool mounting flange of the robot arm into the robot arm, i.e. into its structure, from one joint to a subsequent joint. In addition, forces and moments originating from the robot arm's own weight must also be transmitted to the base frame of the robot arm. For this purpose, each link of the robot arm has at least one structural part designed to absorb and transmit these forces and moments. Such a structural part is generally hollow and can, for example, consist of a cast metal part or a welded steel construction, which can, for example, have pipe sections.Each link is connected, in particular rotatably connected, to an immediately following link of the robot arm via one of the joints. For this purpose, the respective joint can have a pivot bearing. Each pivot bearing can be assigned a sealing arrangement, such as a radial shaft seal. A separate drive motor, such as an electric motor, in particular a servomotor, with associated drive control can be automatically coupled to each joint or pivot bearing. The drives are generally controlled by a robot controller of the robot. The robot controller can adjust the joints using the drives either automatically according to a robot program or drive-controlled during manual operation of the robot in order to change the configuration of the robot arm. A configuration is understood to be the set of current, individual axis angle positions of the joints of the robot arm.

[0010] In order to be able to control the drive motors via the robot controller, the robot controller is connected to all drive motors via a power cable harness. In the case of electric drive motors, the power cable harness can be formed by a bundle of several electrical cables, with at least one electrical cable leading to each of the drive motors. Since such a power cable harness is generally introduced via a base frame of the robot arm and guided along the robot arm to the drive motor of the last, i.e., the distal end joint, the power cable harness runs along or through the entire robot arm with corresponding cable branches and associated cable cross-section reductions. Depending on the design of the robot arm, the power cable harness can be laid completely within the hollow links, i.e., the hollow structural parts of the robot arm, or externally along the links, i.e.,the structural parts of the robot arm, which then do not necessarily have to be hollow.

[0011] Even if the links of the robot arm are designed as hollow structural parts, it may be expedient or even necessary, for example due to the design of the joints, the construction of gears and the arrangement of the drive motors, for a power line harness guided within one of the hollow links to be led out of a first link, i.e. out of a first hollow structural part, in the region of one or more of the joints of the robot arm, to be led outside the links or outside the hollow structural parts around the relevant joint and then to be led again into the immediately following second link, i.e. into the second hollow structural part. The power line harness can have lines for conducting electrical current, in particular for supplying at least one of the drive motors, electrical signals and / or process fluids, in particular gases, liquids such as cooling water and oil or mixtures thereof.The power line harness can simply be referred to as a cable.

[0012] By guiding the intermediate strand section in a cable guiding device which comprises an energy cable strand drum or, synonymously, a cable drum, wherein the cable drum orIf the power cable strand drum has a guide groove extending at least over part of its circumference, in which guide groove the first strand section is guided for at least partial winding and unwinding during rotation of the cable drum, and the cable drum has a central outlet opening from which the second strand section is led out axially, the cable drum being fastened to the second structural part and the intermediate strand section being guided in at least one connecting channel of the cable drum connecting the guide groove to the outlet opening, a particularly reliable cable guiding device on a robot arm is created, by means of which the intermediate strand section of the power cable strand is guided particularly gently via a joint of the robot arm from a first structural part to a second structural part.

[0013] The cable guide device according to the invention is particularly suitable for rotary joints. The cable drum can be secured to one of the structural components forming the respective joint. In this case, the cable drum rotates simultaneously with the structural component to which the cable drum is attached. Preferably, the central outlet opening of the cable drum is located on the rotational axis of the respective joint. Since the cable drum is firmly connected to the rotating or at least pivoting structural component, there is no relative movement between this structural component and the cable drum. This means that the second strand section of the power line strand emerging from the central outlet opening of the cable drum is not subjected to any torsional loading about the rotational axis of the respective joint. This significantly contributes to protecting the power line strand.

[0014] Even within the cable drum, the power cable strand is guided in the connecting channel in a torsion-free and bend-free manner. For this purpose, the intermediate strand section can be fixed in the connecting channel, at least along its longitudinal extent. For example, the intermediate strand section can be clamped in the connecting channel. In this respect, the connecting channel can also function as a conventional strain relief grommet or strain relief clamp.

[0015] The inventive solution thus comprises a cable reel and, if necessary, an excess length compensation device. The cable, i.e., the power line harness, can be wound around the circumference in a guide groove on the cable reel. The cable is statically routed within the cable reel to the center, i.e., the axis of rotation of the joint, and is guided axially out from there. The cable reel can preferably be connected to the output-side structural component of the joint in question or directly to an output of the joint gear, so that the cable, i.e., the power line harness, is statically routed after passing through the center of the cable reel and performs no further movement.

[0016] As the cable is unwound and / or wound up, the portion of the first strand section after the cable reel lengthens or shortens, respectively, particularly in a cable storage unit of the cable guide device. This necessary excess cable length can be stored in an excess length compensation unit, i.e., in the cable storage unit. The cable can be laid there in a loop, for example. To prevent the cable from dragging uncontrollably against the surrounding structure and causing wear, the excess length compensation unit can be guided.

[0017] The robot arm can in particular comprise: a plurality of joints connected by links, which are adjustable in a drive-controlled manner by drive motors of the robot arm, which are coupled to the joints, in order to change the arm position, wherein a first link is connected to a second link by one of the joints, over which a power line strand of the robot arm, which is designed to transmit drive energy to the at least one drive motor, is guided, wherein the first link comprises a first hollow structural part, within which a first strand section of the power line strand is guided, the second link comprises a second hollow structural part, within which a second strand section of the power line strand is guided, and the power line strand comprises an intermediate strand section running between the first strand section and the second strand section, characterized in thatthat the intermediate strand section is guided in a cable guide device which comprises a cable drum, wherein the cable drum has a guide groove extending at least over its partial circumference, in which the first strand section is guided for at least partial winding and unwinding upon rotation of the cable drum, and the cable drum has a central outlet opening from which the second strand section is led out axially, wherein the cable drum is fastened to the second hollow structural part and the intermediate strand section is guided in at least one connecting channel of the cable drum connecting the guide groove to the outlet opening.

[0018] The cable drum can have a first cable drum half and a second cable drum half connected to the first cable drum half, wherein the first cable drum half has a first side cheek running around its circumference, which forms a first side wall of the guide groove and the second cable drum half has a second side cheek running around its circumference, which forms a second side wall of the guide groove, and wherein a circumferential shoulder on the first cable drum half and / or on the second cable drum half forms a groove base of the guide groove.

[0019] The two cable drum halves can be designed with mirror symmetry, so that the two cable drum halves complement each other to form the cable drum when their surfaces facing one another are in contact. The respective side wall of the guide groove can thus be formed by a circumferential shoulder in the edge region of the respective cable drum half. Half of the groove base can be formed by a circumferential cylindrical wall that is set back radially inwards compared to the outer circumference of the circular disk-shaped cable drum half. On the axial outside, a circular ring-shaped side cheek, which forms the respective side wall of the guide groove, complements the set-back circumferential cylindrical wall or the groove base. In the case of a straight, radially extending channel half of a connecting channel for each cable drum half, the two cable drum halves can be of identical design.Otherwise, the two cable drum halves can be mirror-symmetrical.

[0020] According to the invention, the cable drum comprises a first cable drum half and a second cable drum half connected to the first cable drum half. The first cable drum half has a first separating surface facing the second cable drum half, in which a first channel half of the connecting channel is formed, and the second cable drum half has a second separating surface facing the first cable drum half, in which a second channel half of the connecting channel is formed, complementing the first channel half. In particular, the second cable drum half can be detachably connected to the first cable drum half.

[0021] The first channel half of the connecting channel and the second channel half of the connecting channel can be formed by groove-like depressions in the respective separating surface of the cable drum half. The groove-like depressions can have a semicircular cross-section. Within the connecting channel, which is formed when two cable drum halves are placed together at the separating surfaces, the power cable strand can be guided as a bundle of cables or in the form of individual cables. There can be a single connecting channel in the cable drum. Alternatively, there can also be two or more connecting channels in the cable drum. If there are two or more connecting channels in the cable drum, then a corresponding number of individual cables or several bundles of cables can be guided separately in the various connecting channels, i.e. spatially separated from one another in the cable drum.

[0022] The first cable drum half can have first through-holes and the second cable drum half can have second through-holes which are aligned with one another in a joined state of the first cable drum half and the second cable drum half, wherein screws projecting through the first through-holes and the second through-holes are provided, which on the one hand connect the first cable drum half and the second cable drum half to one another and on the other hand the joined cable drum is fastened to the second structural part.

[0023] In addition to the first through holes and second through holes, the cable drum halves can have blind holes or blind recesses and corresponding pin projections, wherein the pin projections engage positively with the blind recesses when the two cable drum halves are assembled to form the cable drum.

[0024] The at least one connecting channel, in particular the first channel half of the connecting channel and the second channel half of the connecting channel, can have a curved course in the radial direction.

[0025] The at least one connecting channel extends radially between the guide groove and the central outlet opening, however, in the case of a curved path, not along a straight line, but rather, for example, along an arcuate, in particular circular, path. The arcuate path can thus optionally have a constant curvature or a changing curvature, in particular one that increases continuously toward the center.

[0026] The cable drum can have two or more connecting channels for a plurality of individual lines of the power line strand, wherein at least a first individual line is laid in a first connecting channel and at least a second individual line is laid in at least one second connecting channel. With the two or more connecting channels, which are preferably formed in two cable drum halves of the cable drum which are joined together at the separating surfaces, the power line strand can be guided in the form of two or more bundles of lines or in the form of two or more individual lines. There can therefore be two or more connecting channels in the cable drum. If there are two or more connecting channels in the cable drum, then a corresponding number of individual lines or several bundles of lines can be guided separately in the various connecting channels, ie spatially separated from one another in the cable drum.

[0027] The intermediate strand section can be guided loosely through the connecting channel, in particular without clamping within the connecting channel.

[0028] Due to the connecting channel, and particularly in the case of a curved connecting channel, the intermediate strand section can be inserted at least largely stress-free, without the intermediate strand section being crushed. Because the intermediate strand section lies at least largely flush in the connecting channel, the intermediate strand section is positioned with sufficient precision, and there is no risk of slipping in the longitudinal direction of the intermediate strand section, even if the intermediate strand section is not clamped, i.e., if it is guided through the connecting channel without clamping.

[0029] In a first basic embodiment, the cable guide device can comprise a cable storage device assigned to the cable drum, in which the first strand section is guided at least in sections, wherein the cable storage device is designed to receive a length of the first strand section running from the guide groove of the cable drum during its rotation into the cable storage device and to release a length of the first strand section running into the guide groove of the cable drum during its opposite rotation from the cable storage device.

[0030] In a basic embodiment, the cable storage device can be formed solely by a space in the cable guide device, which can also be an interior space of a structural part of the robot arm, in which at least a U-shaped section of the first strand section is inserted. The section of the first strand section facing away from the cable drum, which is stationary in this respect, can be fixed in a circular static guide. The circular static guide can extend, for example, by approximately 270 degrees. The circular static guide can be formed in a holding part in which the stationary section of the first strand section is inserted. The holding part can be firmly connected to the first structural part of the robot arm.

[0031] In a second basic embodiment, the cable guide device can have a tensioning device which is designed to apply a tensile force to the first strand section, which holds the first strand section running off the cable drum under a tensile stress in the cable storage despite a rotation of the cable drum, wherein the tensioning device is an energy guide chain which encompasses the first strand section in the cable storage and has a plurality of chain links, of which two adjacent chain links are connected via a respective spring hinge.

[0032] The first strand section is guided by the energy guide chain. For example, the first strand section can be guided within the energy guide chain. The first strand section can, for example, be arranged in a U-shaped curve, with the energy guide chain following this U-shape. The chain links exert a force on the first strand section, which applies tensile stress to the first strand section. Two adjacent chain links are connected to one another in an articulated manner, in particular hinge-like, so that they can move relative to one another. Two adjacent chain links are each connected via a spring hinge, so that all the spring hinges and chain links together generate forces that tend to stretch the energy guide chain and thus the first strand section.Due to this urge to stretch the energy chain, the first strand section is pulled off the cable reel by the energy chain or is held under a spring-loaded tensile stress.

[0033] In a third basic embodiment, the cable guide device can have a tensioning device which is designed to apply a tensile force to the first strand section, which holds the first strand section running off the cable drum under a tensile stress in the cable storage despite a rotation of the cable drum, wherein the tensioning device has a roller which is pressed against a loop section of the first strand section in the cable storage by means of a tension spring in order to impose a tensile stress on the first strand section.

[0034] The first strand section is also arranged in a U-shaped curve, and the roller rests with its inner circumferential side against the U-shaped first strand section. The tension spring presses the roller against the throat area of ​​the U-shaped first strand section, exerting a tensile force on the first strand section, which attempts to pull the first strand section off the cable reel.

[0035] In a fourth basic embodiment, the cable guide device can have a support device which is designed to prevent a lateral deflection of the first strand section transversely to its longitudinal extent when, due to a rotation of the cable drum, the first strand section running off the cable drum is pushed into the cable storage device under the action of pressure from the cable drum, wherein the support device has a support roller which is rotatably mounted on the cable guide device and which supports a section of the first strand section running off tangentially from the cable drum on the outside of this section with its circumferential surface.

[0036] In the fourth basic embodiment, the cable guide device can have a support device which is designed to prevent lateral deflection of the first strand section transversely to its longitudinal extent when, due to a rotation of the cable drum, the first strand section running from the cable drum is pushed into the cable storage device under the action of pressure from the cable drum, wherein the support device, alternatively or in addition to the support roller rotatably mounted on the cable guide device, has a plurality of stationary circumferential rollers distributed along the circumference of the cable drum, which are rotatably mounted on the cable guide device and which secure the section of the first strand section wound on the cable drum against radial deflection from the cable drum by supporting the wound section of the first strand section radially from the outside in places.

[0037] In a fifth basic embodiment, the cable guide device can have a support device which is designed to prevent lateral deflection of the first strand section transversely to its longitudinal extent when, due to a rotation of the cable drum, the first strand section running from the cable drum is pushed into the cable storage device under the action of compressive force from the cable drum, wherein the support device has one or more stationary circumferential guide slideways extending along the circumference of the cable drum, which are fastened to the cable guide device and which secure the section of the first strand section wound on the cable drum against radial deflection from the cable drum by supporting the wound section of the first strand section radially from the outside in places or in sections.

[0038] In general, the cable guiding device, in particular the cable storage, can be attached to the first structural part.

[0039] Specific embodiments of the invention are explained in more detail in the following description with reference to the accompanying figures. Regardless of the specific context in which they are mentioned, specific features of these exemplary embodiments may represent general features of the invention, even when considered individually or in further combinations.

[0040] They show: Fig. 1 is a perspective view of an exemplary robot arm, Fig. 2 is a perspective view of an exemplary first embodiment of a cable guiding device according to the invention in the basic structure, Fig. 3 is a perspective view of an exemplary cable drum half of a cable drum according to the invention of the cable guiding device, Fig. 4 is a perspective view of an exemplary second embodiment of a cable guiding device according to the invention with a spring preload by means of an energy guiding chain, Fig. 5 is a perspective view of an exemplary third embodiment of a cable guiding device according to the invention with a spring preload by means of a roller and tension spring, Fig.Fig. 6 is a perspective view of an exemplary fourth embodiment of a cable guide device according to the invention with a support device in the form of small stationary, rotatable circumferential rollers and a large support roller, and Fig. 7 is a perspective view of an exemplary fifth embodiment of a cable guide device according to the invention with a support device in the form of guide slideways.

[0041] The Fig. 1 shows an exemplary robot 1 with a robot controller 2 and a robot arm 3. The robot arm 3 has a base frame 5 as the first link G1, on which a carousel 7 as the second link G2 is mounted so as to be rotatable about a first vertical axis A1 and is rotationally driven by a first drive motor M1. The axes A1-A6 of the robot arm 3 can also be referred to as joints L1-L6 of the robot arm 3. A rocker arm 9 as the third link G3 is mounted on the carousel 7 so as to be pivotable up and down about a second horizontal axis A2 and is rotationally driven by a second drive motor M2. The rocker arm 9 carries an arm boom 11, which is mounted so as to be pivotable up and down about a third horizontal axis A3 and is rotationally driven by a third drive motor M3.On the arm extension 11, whose base arm forms a fourth link G4, a fourth axis A4 is provided, which runs in the longitudinal extension of the arm extension 11 and rotatably drives a front arm 15 via a fourth drive motor (not shown). A first leg 15a and a second leg 15b extend forward from the front arm 15 in a forked manner. The two legs 15a, 15b carry a bearing for a hand 13, which forms a sixth link G6. The bearing defines a fifth axis A5 of the robot arm 3, about which the hand 13 can be pivoted by means of a fifth drive motor (not shown). In addition, the hand 13 has a sixth axis A6 in order to be able to rotatably drive a mounting flange 16, which forms a seventh link G7, by means of a sixth drive motor (not shown).Each axis A1 to A6 is assigned a joint L1 to L6. In the illustrated embodiment, these joints L1 to L6 connect the links G1 to G7 in the manner of a serial kinematics of a kick-arm robot. A cable guide device 20 according to the invention can be provided in particular at joint L5, which pivotally connects the hand 13, i.e., link G6, to the forearm 15, i.e., link G5.

[0042] In the following, reference is made to Fig. 2 bis Fig. 7 The cable guide device 20 for a power line harness 17 is described. The power line harness 17 of the robot arm 3 is designed to transmit drive energy to the at least one drive motor M1-M6. A first member of the members G1-G7 has a first hollow structural part, within which a first strand section 17.1 of the power line harness 17 is guided; an adjacent second member of the members G1-G7 has a second hollow structural part, within which a second strand section 17.2 of the power line harness 17 is guided. The power line harness 17 also has an intermediate strand section 17.3 running between the first strand section 17.1 and the second strand section 17.2.

[0043] The intermediate strand section 17.3 is guided in the cable guide device 20, which comprises a cable drum 21, wherein the cable drum 21 has a guide groove 22 extending at least over its partial circumference, in which the first strand section 17.1 is guided for at least partial winding and unwinding upon rotation of the cable drum 21 and the cable drum 21 has a central outlet opening 23, from which the second strand section 17.2 is led out axially, wherein the cable drum 21 is fastened to the second hollow structural part and the intermediate strand section 17.3 is guided in at least one connecting channel 24 connecting the guide groove 22 with the outlet opening 23 ( Fig. 3 ) of the cable drum 21.

[0044] The cable drum 21 has a first cable drum half 21.1 and a second cable drum half 21.2 connected to the first cable drum half 21.1, wherein the first cable drum half 21.1 has a first side cheek 25.1 running around its circumference, which forms a first side wall of the guide groove 22, and the second cable drum half 21.2 has a second side cheek 25.2 running around its circumference ( Fig. 4 ), which forms a second side wall of the guide groove 22. A circumferential shoulder 26 on the first cable drum half 21.1 (and on the second cable drum half 21.2) forms a groove base of the guide groove 22.

[0045] The first cable drum half 21.1 has a first separating surface 27.1 facing the second cable drum half 21.2, in which a first channel half 24.1 of the connecting channel 24 is formed, and the second cable drum half 21.2 has a second separating surface facing the first cable drum half 21.1, in which a second channel half of the connecting channel 24 is formed, supplementing the first channel half 24.1.

[0046] The first cable drum half 21.1 has first through holes 28.1 and the second cable drum half 21.2 has second through holes 28.2, which in a joined state of the first cable drum half 21.1 and the second cable drum half 21.2 (see Fig. 4 bis Fig. 7 ) are aligned with each other, wherein screws 29 projecting through the first through holes 28.1 and the second through holes 28.2 are provided, which on the one hand connect the first cable drum half 21.1 and the second cable drum half 21.2 to each other, and on the other hand the joined cable drum 21 can be fastened to the second structural part.

[0047] As in Fig. 3 As shown, the connecting channel 24, in particular the first channel half 24.1 of the connecting channel 24 and the second channel half 24.2 of the connecting channel 24, can have a curved course in the radial direction.

[0048] In the first embodiment according to Fig. 2 the cable guiding device 20 has a cable storage 30 assigned to the cable drum 21, in which the first strand section 17.1 is guided at least in sections, wherein the cable storage 30 is designed to receive a length of the first strand section 17.1 running from the guide groove 22 of the cable drum 21 during its rotation into the cable storage 30 and to release a length of the first strand section 17.1 running into the guide groove 22 of the cable drum 21 during its opposite rotation from the cable storage 30.

[0049] In the second embodiment according to Fig. 4 the cable guide device 20 has a tensioning device 31 which is designed to apply a tensile force to the first strand section 17.1, which holds the first strand section 17.1 running from the cable drum 21 under tensile stress in the cable storage 30 despite a rotation of the cable drum 21, wherein the tensioning device 31 is an energy guide chain 32 which encompasses the first strand section 17.1 in the cable storage 30 and has a plurality of chain links 33, of which two adjacent chain links 33 are each connected via a spring hinge 34.

[0050] In the third embodiment according to Fig. 5 the cable guide device 20 has a tensioning device 31 which is designed to apply a tensile force to the first strand section 17.1, which holds the first strand section 17.1 running off the cable drum 21 under a tensile stress in the cable storage 30 despite a rotation of the cable drum 21, wherein the tensioning device 31 has a roller 35 which is pressed in the cable storage 30 by means of at least one tension spring 36 against a loop section of the first strand section 17.1 in order to impose a tensile stress on the first strand section 17.1.

[0051] In the fourth embodiment according to Fig. 6 the cable guide device 20 has a support device 37 which is designed to prevent lateral deflection of the first strand section 17.1 transversely to its longitudinal extent when, due to a rotation of the cable drum 21, the first strand section 17.1 running off the cable drum 21 is pushed into the cable storage 30 under the action of pressure from the cable drum 21, wherein the support device 37 has a support roller 38 which is rotatably mounted on the cable guide device 20 and which supports a section of the first strand section 17.1 running off tangentially from the cable drum 21 on the outside of this section with its circumferential surface.

[0052] In the fourth embodiment according to Fig. 6 the cable guide device 20 also has a support device 37 which is designed to prevent lateral deflection of the first strand section 17.1 transversely to its longitudinal extent when, due to a rotation of the cable drum 21, the first strand section 17.1 running from the cable drum 21 is pushed into the cable storage 30 under the action of pressure from the cable drum 21, wherein the support device 37 has a plurality of stationary circumferential rollers 39 which are distributed along the circumference of the cable drum 21 and which are rotatably mounted on the cable guide device 20 and which secure the section of the first strand section 17.1 wound up on the cable drum 21 against radial deflection from the cable drum 21 by supporting the wound up section of the first strand section 17.1 radially from the outside in places.

[0053] In the fifth embodiment according to Fig. 7the cable guide device 20 has a support device 37 which is designed to prevent lateral deflection of the first strand section 17.1 transversely to its longitudinal extent when, due to a rotation of the cable drum 21, the first strand section 17.1 running from the cable drum 21 is pushed into the cable storage 30 under the action of pressure from the cable drum 21, wherein the support device 37 has one or more stationary circumferential guide slideways 40.1 extending along the circumference of the cable drum 21, which are fastened to the cable guide device 20 and which secure the section of the first strand section 17.1 wound up on the cable drum 21 against radial deflection from the cable drum 21 by supporting the wound up section of the first strand section 17.1 radially from the outside in places or in sections. The support device 37 can additionally have a guide rail 40.2, which supports a section of the first strand section 17.1 running tangentially from the cable drum 21 on the outside of this section.

Claims

1. Robot arm comprising a plurality of joints (L1-L6) connected by links (G1-G7), which are moveable in a drive-controlled manner by drive motors (M1-M6) of the robot arm (3) which are coupled to the joints (L1-L6), in order to change the arm position, wherein a first link (G1-G7) is connected to a second link (G1-G7) by one of the joints (L1-L6) through which an energy supply line (17) of the robot arm (3) is guided, wherein the first link (G1-G7) comprises a first structural part on which a first strand section (17.1) of the energy supply line (17) is guided, the second link (G1-G7) comprises a second structural part on which a second strand section (17.2) of the energy supply line (17) is guided, and the energy supply line (17) comprises an intermediate strand section (17.3) extending between the first strand section (17.1) and the second strand section (17.2), wherein the intermediate strand section (17.3) is guided in a cable guide device (20) which comprises a cable drum (21), wherein the cable drum (21) comprises a guide groove (22) extending at least over part of its circumference, in which the first strand section (17.1) is guided for at least partial winding and unwinding during rotation of the cable drum (21), and the cable drum (21) comprising a central outlet opening (23) from which the second strand section (17.2) is guided axially out of the cable drum (21), wherein the cable drum (21) is fastened to the second structural part and the intermediate strand section (17.3) is guided in at least one connecting channel (24) of the cable drum connecting the guide groove (22) with the outlet opening (23), characterized in that the cable drum (21) comprises a first cable drum half (21.1) and a second cable drum half (21.2) connected to the first cable drum half (21.1), wherein the first cable drum half (21.1) has a first separating surface (27.1) facing the second cable drum half (21.2), in which a first channel half (24.1) of the connecting channel (24) is formed, and the second cable drum half (21.2) has a second separating surface (27.2) facing the first cable drum half (21.1), in which a second channel half (24.2) of the connecting channel (24) is formed, which complements the first channel half (24.1).

2. Robot arm according to claim 1, characterized in that the cable drum (21) has a first cable drum half (21.1) and a second cable drum half (21.2) connected to the first cable drum half (21.1), wherein the first cable drum half (21.1) has a first side wall (25.1) extending around its circumference, which forms a first side wall of the guide groove (22), and the second cable drum half (21.2) has a second side wall (25.2) extending around its circumference which forms a second side wall of the guide groove (22), and wherein a circumferential shoulder (26) on the first cable drum half (21.1) and / or on the second cable drum half (21.2) forms a groove base of the guide groove (22).

3. Robot arm according to claim 1 or 2, characterized in that the cable drum (21) has two or more connecting channels (24) for multiple individual cables of the energy supply line (17), wherein at least one first individual cable is inserted in a first connecting channel (24) and at least one second individual cable is inserted in at least one second connecting channel (24).

4. Robot arm according to any one of claims 1 to 3, characterized in that the cable guide device (20) comprises a cable storage device (30) assigned to the cable drum (21), in which the first strand section (17.1) is guided at least in a section, wherein the line storage device (30) is designed to receive a length of the first strand section (71.1) running out of the guide groove (22) of the cable drum (21) during its rotation and running out a length of the first strand section (71.1) out of the storage device (30), which is received in the guide groove (22) of the cable drum (21) during its opposite rotation.

5. Robot arm according to claim 4, characterized in that the cable guide device (20) comprises a tensioning device (31) which is designed to apply a tensile force to the first strand section (17.1) which holds the first strand section (17.1) running off the cable drum (21) under tension, despite rotation of the cable drum (21), wherein the tensioning device (31) comprises an energy guide chain (32) with several chain links (33) surrounding the first strand section (17.1) in the cable storage device (30), with two adjacent chain links (33) connected to each other via a spring hinge (34).

6. Robot arm according to claim 4, characterized in that the cable guide device (20) comprises a tensioning device (31) which is designed to apply a tensile force to the first strand section (17.1) which holds the first strand section (17.1) running off the cable drum (21) running off the cable drum (21) under tension, despite rotation of the cable drum (21), wherein the tensioning device (31) has a roller (35) which is pressed in the cable storage device (30) by means of a tension spring (36) against a loop section of the first strand section (17.1) in order to apply tension to the first strand section (17.1).

7. Robot arm according to claim 4, characterized in that the cable guide device (20) comprises a support device (37) which is designed to prevent lateral displacement of the first strand section (17.1) transversely to its longitudinal extension when, due to a rotation of the cable drum (21), the first strand section (17.1) running off the cable drum (21) is pushed into the cable storage device (30) under the effect of pressure force originating from the cable drum (21), wherein the support device (37) has a support roller (38) mounted rotatably on the cable guide device (20), which supports a section of the first strand section (17.1) running tangentially from the cable drum (21) with its peripheral surface abutting the outside of this section.

8. Robot arm according to claim 4, characterized in that the cable guide device (20) comprises a support device (37) which is designed to prevent lateral displacement of the first strand section (17.1) transversely to its longitudinal extension when, due to rotation of the cable drum (21), the first strand section (17.1) running off the cable drum (21) is pushed into the cable storage device (30) under the effect of pressure force originating from the cable drum (21), wherein the support device (37) comprises a plurality of stationary circumferential rollers (39) distributed along the circumference of the cable drum (21), which are rotatably mounted on the cable guide device (20) and which secure the section of the first strand section (17.1) being wound on the cable drum (21) against radial displacement from the cable drum (21) by supporting the wound section of the first strand section (17.1) radially from the outside at some places.

9. Robot arm according to claim 4, characterized in that the cable guide device (20) comprises a support device (37) which is designed to prevent lateral displacement of the first strand section (17.1) transversely to its longitudinal extension when, due to rotation of the cable drum (21), the first strand section (17.1) running off the cable drum (21) is pushed into the cable storage device (30) under the effect of a pressure force originating from the cable drum (21), wherein the support device (37) comprises one or more stationary circumferential guide slides (40) extending along the circumference of the cable drum (21), which are fixedly connected to the cable guide device (20) and which secure the section of the first strand section (17.1) being wound onto the cable drum (21) against radial displacement from the cable drum (21) by supporting the wound section of the first strand section (17.1) radially from the outside at some places or along sections.