Joint arrangement for a robot and robots with such a joint arrangement

Abstract

The invention relates to a joint arrangement (2) for a robot (1), comprising a drive unit (3), an output unit (4), a ball joint (5) connecting the two units (3, 4) articulately, and a first cable (6), a second cable (7), and a third cable (8), wherein the cables (6, 7, 8) are separately actuable, wherein the ball joint (5) has a hollow sphere (10) with a universal joint (9) arranged therein, wherein the universal joint (9) comprises a rotatable first shaft (11) associated with the drive unit (3) and a driven second shaft (12) associated with the output unit (4), wherein the first cable (6) is configured to set a roll angle of the output unit (4) relative to a center (33) of the hollow sphere (10), and wherein the second cable (7) is configured to set a pitch angle of the output unit (4) relative to the center (33) of the hollow sphere (10). (10) to set up,and wherein the third cable (8) is configured to set a yaw angle of the output device (4) relative to the center (33) of the hollow sphere (10). Furthermore, the invention relates to a robot (1) comprising such a joint arrangement (2).

Description

[0001] The invention relates to a joint arrangement for a robot, in particular for a cable-operated robot. Furthermore, the invention relates to a robot, in particular a cable-operated robot, with at least one such joint arrangement.

[0002] KR 10-2011-0088858 A discloses a 3-DOF actuator (the abbreviation "DOF" stands for "degrees of freedom") for a rotary joint of a robot. The actuator comprises a first rotating part that is rotatably connected to the fixed frame, a first drive unit that rotates the first rotating unit about an axis of the fixed frame and is fixedly connected to the first rotating unit, a second rotating part that is rotatably connected to the first rotating part, and a second drive unit that rotates the second rotating unit about an axis orthogonal to the rotation axis of the first rotating unit and is fixedly mounted to the first rotating unit. Furthermore, a third rotating part that is rotatably connected to the second rotating part and a third drive unit that rotates the third rotating unit about an axis orthogonal to the rotation axis of the second rotating unit and is fixedly installed on the second rotating unit are provided.The three degrees of freedom of the actuator for the robot's rotary joints are characterized by the fact that the rotation axes of the three rotating parts intersect at one point.

[0003] US 2017 / 0 095 922 A1 describes a joint consisting of an alternating sequence of links and gimbals. Multiple cables are connected to one or more of the connections. Because these cables are selectively pulled and released, any desired degree of articulation of the joint can be achieved.

[0004] CN 1 08 422 410 A describes a stiffness-adjustable cable-driven bionic parallel robot. This comprises a movable and a fixed platform, a support spring, a linear bearing, a planar bearing and a drive cable, wherein the support spring is fixedly arranged between the movable platform and the fixed platform. The lower end of the support spring is connected to the fixed platform and the upper end is connected to the movable platform by the planar bearing; the support spring is internally provided with an upper spine, a universal joint and a lower spine; the linear bearing is attached to the movable platform and connected to the upper end of the upper spine. The lower end of the upper spine is connected to the upper end of the universal joint; the lower end of the universal joint is connected to the upper end of the lower spine. The lower end of the lower spine is attached to the fixed platform.One end of the drive rope is attached to the moving platform and the other end of the drive rope acts as the driving end.

[0005] US 8 452 453 B2 describes a robot with three motors arranged on a base profile, a support arranged so that an axial centerline is perpendicular to a surface of the base profile, pulleys, three wires in which non-linear springs are incorporated, an output shaft connected to a load, a differential mechanism having a pinion connected to the output shaft, and also a fastening element arranged at the upper end of the support.

[0006] DE 10 2011 108 265 A1 describes an actuating arm for a handling device with a first and a second arm part connected by a joint. A drive device for the joint pivots the two arm parts relative to each other.

[0007] US 5,740,699 A describes an extendable wrist mechanism with a base and a spaced end plate to which an end effector may be mounted. Three linear actuators are arranged around the central axis, which extends from the base to the end plate. Each actuator is connected to the base by a joint, allowing pivoting toward and away from the central axis and tangential pivoting of a circle centered on the central axis. Each linear actuator is attached to the end plate by a joint, allowing pitch, yaw, and roll of the end link relative to the linear actuator.

[0008] DE 10 2010 029 784 B3 describes a robot whose robot drive is connected to the robot head via a spacer rod and a control arm. The robot head comprises a mounting assembly and an actuator assembly coupled to it via a transmission gear. The mounting assembly is connected to the control arm and the spacer rod. The transmission gear converts rotation of the mounting assembly into rotation of the actuator assembly.

[0009] The object of the invention is to provide a joint assembly for a robot that exhibits improved load-bearing behavior while simultaneously offering high flexibility and a compact design. This object is achieved by the subject matter of patent claim 1 and by the subject matter of patent claim 10. Preferred embodiments can be found in the dependent claims, the description, and the figures.

[0010] A joint arrangement according to the invention for a robot comprises a drive device, an output device, a ball joint connecting the two devices in an articulated manner, as well as a first cable pull, a second cable pull and a third cable pull, wherein the cables can be actuated separately, wherein the ball joint has a hollow ball with a universal joint arranged therein, wherein the universal joint comprises a first shaft which is assigned to the drive device and can be driven in rotation, and a second output shaft which is assigned to the output device, wherein the first cable pull is designed to set a roll angle of the output device relative to a center of the hollow sphere, wherein the second cable pull is designed to set a pitch angle of the output device relative to the center of the hollow sphere, and wherein the third cable pull is designed to set a yaw angle of the output device relative to the center of the hollow sphere.

[0011] By operating the first cable pull, the output device rolls relative to the drive device. By operating the second cable pull, the output device pitches relative to the drive device. By operating the third cable pull, the output device yaws relative to the drive device. Roll-pitch-yaw angles are special attitude angles that are used to describe the orientation of an object in three-dimensional space. The roll, pitch, and yaw movements can be summarized as "roll-pitch-yaw motions" (or "RPY" for short). The roll-pitch-yaw movements can be understood as rotations of the output device around the z, y, and x axes, with the z-axis (roll axis), the y-axis (pitch axis), and the x-axis (yaw axis) meeting or intersecting at the center of the hollow sphere.Therefore, the output device always rotates around the center of the hollow sphere during rolling, pitching and / or yawing.

[0012] The center or midpoint of the hollow sphere simultaneously forms the center of the universal joint, and vice versa. The center or midpoint of the hollow sphere thus forms the pivot point of the joint assembly, around which the drive mechanism can rotate relative to the output mechanism, and vice versa. The ball joint is a ball joint with three degrees of freedom, also referred to as a 3-DOF ball joint. The term "3-DOF ball joint" therefore refers to a ball joint that can realize three degrees of freedom (or "DOF" for short).

[0013] The shafts, together with the universal joint, form a cardan shaft with a fundamentally familiar function and act as the center shaft between the drive and output shafts. The universal joint enables torque transmission in a bent shaft train consisting of the shafts and the joint located between them.

[0014] By operating each cable separately, the roll angle, pitch angle, or yaw angle can be adjusted. "Individually operable" in this context means that the cables can be controlled individually and independently of each other to adjust the roll, pitch, or yaw angle of the output device. The ball joint allows two or all cables to be operated simultaneously, but to adjust a combination of roll, pitch, and yaw movements simultaneously.

[0015] With this type of joint design, the drive and output devices can always rotate around the center of the 3-DOF ball joint, specifically the center of the hollow sphere. This allows for high precision in roll, pitch, and yaw movements.

[0016] The use of a universal joint in the ball joint and the independent actuation of each of the aforementioned movements offers high flexibility and expands the angular range that can be covered by the joint assembly. Furthermore, such a joint assembly can be used in applications with high dynamic requirements, as the integration of the ball joint into the joint assembly improves the joint assembly's ability to bear heavy loads and apply large torques. The ball joint, or 3-DOF ball joint, simplifies and compresses the structure of the joint assembly. Thus, the robot, especially a robot arm of the robot that incorporates such a joint assembly, can be designed slimmer and more compact.

[0017] To connect the shafts of the universal joint to the drive device or the output device, the hollow ball of the ball joint preferably has recesses for the shafts to pass through. In other words, the shafts are guided axially through the outer skin of the hollow sphere and connected accordingly. The recesses can be designed in such a way that lateral support of the shafts is possible. The recesses can be designed as elongated holes in the outer skin of the hollow sphere, allowing guided rotation of the respective shaft around the center of the hollow sphere.

[0018] Preferably, the drive device and the output device each have a curved section with a radius that is complementary to the outer diameter. The curved section with the radius can be annular and formed or arranged on a ring segment of the drive device and / or the output device, wherein the ring segment in turn can be arranged on a respective block or support component of the drive device or the output device. Alternatively, the ring segment can be an integral part of the support component. The hollow sphere can slide along the respective curved section when the roll, pitch, and / or yaw angle is adjusted. The smaller the tolerances of the hollow sphere and the curved sections, the lower any friction losses.

[0019] In a further development of the invention, the respective curved section, i.e., the surface facing the hollow sphere and / or the outer skin or outer peripheral surface of the hollow sphere, has a coating and / or means for minimizing friction. As a means for minimizing friction, rolling elements, in particular balls, can be arranged between the respective curved section and the hollow sphere. These rolling elements roll against the curved sections and the hollow sphere during operation or upon actuation of the joint arrangement. The rolling elements can be guided in a cage.

[0020] According to the invention, each cable pull has a first cable and a second cable, wherein the cables of the first cable pull are wound on a cable pulley of the drive device, wherein the cables of the second cable pull are arranged on opposite sides with respect to the hollow sphere and are axially guided on the drive device and fastened to the output device, and wherein the cables of the third cable pull are arranged on opposite sides with respect to the hollow sphere and offset in the circumferential direction of the drive device from the cables of the second cable pull, and are axially guided on the drive device and fastened to the output device. The first and second cables of the respective cable pull each form a cable pair.

[0021] The cable pairs of the second and third cable pulls are arranged axially parallel to each other and offset by 90° from each other, i.e., evenly spaced around the hollow sphere. In other words, in a plan view of the drive mechanism or the output mechanism, a first cable of the first cable pull is circumferentially followed by a first cable of the second cable pull, followed by a second cable of the first cable pull, followed by a second cable of the second cable pull, and followed by the first cable of the first cable pull.

[0022] The pulley for the first cable pull is arranged coaxially with the rest of the drive mechanism and can have one or more windings on which the respective cable of the first cable pull is wound. The pulley is preferably at least indirectly connected in a rotationally fixed manner to the first or driving shaft of the universal joint and transmits a rotational movement to the universal joint, which in turn executes a rolling movement of the output mechanism. To execute the rolling movement powerfully and increase the resulting torque, the radius of the pulley is as large as possible. The larger the outer diameter of the pulley, the higher the operating accuracy during rolling movements and the lower the risk of winding errors during operation.

[0023] According to the invention, the cable pulley is axially supported on a first block of the drive device via a first axial bearing and is mounted rotatably relative thereto. In other words, the cable pulley is supported on the first block of the drive device via the first axial bearing. Thus, the cable pulley is arranged rotatably relative to the block or support component of the drive device. The cable pulley can be connected, for example, by positive locking in a rotationally fixed manner to a drive shaft or a drive yoke, wherein the drive shaft or the drive yoke is connected in a rotationally fixed manner, preferably directly in a rotationally fixed manner, to the rotationally drivable first shaft of the universal joint for torque transmission.

[0024] In a further development of the invention, the first cable of the first cable pulley is deflected by a first deflection pulley, and the second cable of the first cable pulley is deflected by a second deflection pulley. By means of the deflection pulleys, the cables of the first cable pulley can be deflected such that they are arranged essentially axially parallel to the cables of the second and third cable pulleys. The deflection pulleys are provided, in particular, to deflect the cables of the first cable pulley such that the cables can be guided to an actuator arranged axially offset to the rear. The cables of the second and third cable pulleys are also operatively connected to a respective actuator arranged axially offset to the rear.

[0025] To operate the cable pulls, the cables of the respective cable pull are preferably operatively connected to an associated actuator arranged on the drive device. In other words, each cable pull is assigned a separate actuator. Therefore, three actuators are provided, one for each cable pull. The respective actuator is designed and connected to the associated cables of the respective cable pull in such a way that shortening the length of one cable results in a corresponding lengthening of the other cable of the same cable pull, so that the output device can be moved around the center of the hollow sphere and through the hollow sphere. Pulling to shorten the length of one cable therefore causes the other cable of the same cable pull to directly lengthen. Depending on the cable pull, a rolling movement, a pitching movement and / or a yawing movement of the output device is carried out orA roll angle, a pitch angle, and / or a yaw angle of the output device, which is attached to the ends of the cables, is set. The roll, pitch, and / or yaw movements are guided and limited by the shape and design of the 3-DOF ball joint.

[0026] The respective actuator can have a rotary pulley on which the ropes of the respective cable pulley can be wound. The two ropes of the respective cable pulley can be separate ropes. Alternatively, the ropes can be a continuous, one-piece rope, which is wound accordingly on the aforementioned pulley of the actuator or on a cable winch.

[0027] Each cable of the second and third cable pulleys is attached to a block or support of the output device. The cables of the second and third cable pulleys are routed from the output device to the drive device, whereby the drive device can in turn comprise means for guiding, in particular axially, the respective cable, which is / are arranged between the connection point on the output device and the actuator of the respective cable pulley.

[0028] The respective actuator can be designed as an electric machine, comprising a stator fixed to the housing and a rotor rotatably arranged thereon. A rotor or a rotor shaft connected thereto in a rotationally fixed manner can be connected in a rotationally fixed manner to a cable pulley or cable winch for transmitting drive power. Depending on the direction of rotation of the rotor, one cable of the respective cable pair or cable pulley can be wound up and the other cable of the same cable pair or cable pulley can be unwound in the same manner. The second and third cable pulleys are arranged and connected to the output device in such a way that these connection points move in opposite directions and around the center of the hollow sphere when actuated by the respective actuator.

[0029] The output device preferably has a connection plate that is at least indirectly connected in a rotationally fixed manner to the second shaft of the universal joint and is axially supported and rotatably mounted on a second block of the output device via a second axial bearing. The connection plate is designed to accommodate additional components of a robot and connect them to the joint arrangement. The connection plate can have corresponding means for accommodating these components, for example, threaded holes, through openings, recesses, or the like. The connection plate can be designed in the shape of an annular disk.

[0030] The output device preferably comprises an output shaft that is at least indirectly connected in a rotationally fixed manner to the second shaft of the universal joint, wherein the output shaft is connected in a rotationally fixed manner to the connecting plate via a star lock. The output shaft can be directly connected in a rotationally fixed manner to the second shaft of the universal joint in order to transmit a rotational movement and a torque to the connecting plate. The star lock creates a positive connection between the output shaft and the connecting plate.

[0031] The wording “at least indirectly” means that two components are (actively) connected to one another via at least one further component arranged between the two components or are directly and thus immediately connected to one another.

[0032] In this context, the term “operatively connected” or “operative connection” refers in particular to a non-switchable connection between two components which is intended for the permanent transmission of a rotational speed and / or a torque. The connection can be direct, i.e. immediately, or indirect, for example via a fixed gear ratio. The connection can be made, for example, via a fixed shaft, a gear toothing, in particular a spur gear toothing, and / or a belt or traction device, in particular chains or belts. In the case of an indirect connection, another component can be arranged between the two components. For example, further shafts and / or gears can be operatively arranged between two shafts.

[0033] The invention further relates to a robot comprising at least one joint arrangement according to the above embodiments. In particular, the joint arrangement according to the invention is arranged in a robot arm or robot arm segment, for example in a robot arm joint, of the robot and acts at least indirectly on at least the robot arm or one of the robot arm segments of the robot arm. The robot is preferably a cable-operated robot.

[0034] The above definitions as well as explanations of technical effects, advantages and advantageous embodiments of the joint arrangement according to the first aspect of the invention also apply mutatis mutandis to the robot according to the second aspect of the invention, and vice versa.

[0035] Further measures improving the invention are described in more detail below together with the description of a preferred embodiment of the invention with reference to the figures. Fig. 1 a schematic representation of a partially shown robot according to the invention in the form of a cable-operated robot, Fig. 2 a first schematic perspective view of an inventive joint arrangement of the robot according to Fig. 1, Fig. 3 a second schematic perspective view of the joint arrangement according to the invention of the robot according to Fig. 1 and Fig. 2, Fig. 4 a schematic perspective view of a ball joint of the joint arrangement according to the invention according to Fig. 1 to Fig. 3, Fig. 5 a schematic view of a drive device of the joint arrangement according to the invention according to Fig. 1 to Fig. 4, Fig. 6 a first schematic exploded view of the drive device according to Fig. 5, Fig. 7 a second schematic exploded view of the drive device - shown here only partially - according to Fig. 5 and Fig. 6, Fig. 8 a schematic view of an output device of the joint arrangement according to the invention according to Fig. 1 to Fig. 4, Fig. 9 a schematic exploded view of the drive device according to Fig. 8, and Fig. 10 a schematic plan view of the drive device according to Fig. 8 and Fig. 9.

[0036] According to Fig. 1 shows a highly schematic and simplified representation of a robot arm 30 of a robot 1—only partially shown here. The robot 1 is designed as a cable-operated robot, with the robot arm 30 correspondingly forming a cable-operated robot arm. In this example, the robot arm 30 has a first robot arm segment 31 and a second robot arm segment 32, which are connected to one another in an articulated, i.e. pivotable, manner via a joint arrangement 2 according to the invention, which forms the robot arm joint. The structure and function of the joint arrangement 2 are described in more detail below.

[0037] After Fig. 2 and Fig. 3, the joint arrangement 2 comprises a drive device 3, an output device 4, a ball joint 5 connecting the two devices 3, 4 in an articulated manner, as well as a first cable 6, a second cable 7, and a third cable 8, wherein each cable 6, 7, 8 has a first cable 6a, 7a, 8a and a second cable 6b, 7b, 8b. The cable 6, 7, 8 can each be actuated separately via an actuator 22, 23, 24. The actuators 22, 23, 24 are in Fig. 3 indicated by dashed rectangles arranged on the drive device 3.

[0038] The ball joint 5 has a hollow ball 10 with a cardan joint 9 arranged therein. The ball joint 5 is isolated and detailed in Fig. 4. Accordingly, recesses 13, 14 in the form of elongated holes are formed on the outer skin of the hollow sphere 10, which are provided for receiving and guiding a first shaft 11 or a second shaft 12 of the universal joint 9, wherein the shafts 11, 12 are connected to one another in an articulated manner. In the following description, the first shaft 11 is assigned to the drive device 3 and functions as the rotationally driving or driving element of the universal joint 9. The second shaft 12 is assigned to the output device 4 and functions as the output element of the universal joint 9.

[0039] The meeting or intersection point of the Fig. 4 shown coordinate system with the x, y and z axes is to be understood as the center 33 of the joint arrangement 2, the hollow ball 10 and the cardan joint 9, wherein the output device 4 is rotatable about the x, y and / or z axis depending on an actuation of the cables 6, 7, 8 in order to adjust a roll, pitch and / or yaw angle of the output device 4 relative to the drive device 3, and vice versa.

[0040] According to the Fig. 2 and Fig. 3, the first cable pull 6 is designed to adjust a roll angle of the output device 4 relative to the center 33 of the hollow sphere 10. The second cable pull 7 is designed here to adjust a pitch angle of the output device 4 relative to the center 33 of the hollow sphere 10. The third cable pull 8 is designed to adjust a yaw angle of the output device 4 relative to the center 33 of the hollow sphere 10. Regardless of a separate or simultaneous actuation of the cables 6, 7, 8, the drive device 3 and the output device always rotate around the center 33 of the operatively connected ball joint 5 or the hollow sphere 10.

[0041] The Fig. 5 to 7 show the structure of the drive device 3 in detail. The drive device 3 is to be understood as a driving base and here has a first block 19 and a third block 34, which are arranged axially spaced from one another by means of four spacer sleeves 40 and two deflection rollers 20, 21. The drive device 3 is arranged around a drive shaft 35. The drive shaft 35 is rotatably arranged relative to the blocks 19, 34 and is axially supported. The drive shaft 35 is non-rotatably connected to the first shaft 11 according to Fig. 4. The blocks 19, 34 are firmly connected to each other by six screws 36 (see in particular Fig. 6), whereby four of the six screws 36 are guided through a respective associated spacer sleeve 40 and the other two of the six screws 36 are guided through the deflection rollers 20, 21. The third block 34 is to be understood as a connecting part between the joint arrangement 2 and further - not shown here - components of the robot arm 30, in particular the first robot arm segment 31. Each deflection roller 20, 21 has Fig. 6 has a horizontal shaft 37 on which a roller 38 is rotatably mounted for deflecting or changing the direction of one of the cables 6a, 6b of the first cable pull 6. The shaft 37 is rotatably mounted on a spacer 39, with the roller 38 being rotatably mounted within the spacer 39. Fig. 6 further shows that a tube section 41 or ring segment is formed on a side of the first block 19 opposite the spacer sleeves 40 and deflection rollers 20, 21, on which a curved section 15 is formed with a radius which is designed to slidably receive the hollow ball 10 of the ball joint 5.

[0042] Between the blocks 19, 34, a pulley 17 is arranged, which is connected in a rotationally fixed manner to the drive shaft 35 or the first shaft 11 and is rotatably arranged on the first block 19 via a first axial bearing 18 and is axially supported thereon. Fig. 7, a hexagonal recess 43 is formed on the cable pulley 17, in which a complementary nut 42, which is connected in a rotationally fixed manner to the drive shaft 35, is axially received and arranged in a rotationally fixed manner.

[0043] The ropes 6a, 6b of the first rope pulley 6 are, as in Fig. 3, wound on the cable pulley 17. The first actuator 22 is designed to actuate the cables 6a, 6b deflected by the deflection rollers 20, 21 such that the cable pulley 17 can rotate selectively clockwise or counterclockwise about its axis of rotation relative to the blocks 19, 34 of the drive device 3, whereby the drive shaft 35 is set into a rotational movement. The rotation of the drive shaft causes a rotation of the shafts 11, 12 of the universal joint 9, wherein the second shaft 12 of the universal joint 9 transmits the drive power to the output device 4 in order to execute a rolling movement of the output device 4 relative to the drive device 3, specifically by the Fig. 2. The respective deflection pulleys 20, 21 are arranged between the cable pulley 17 and the first actuator 22. The radius or diameter of the cable pulley 17 is selected so that the rolling movement can be powerful, i.e., with a high resulting torque.

[0044] The structure of the output device 4 should be Fig. 8 to 10. The output device 4 is to be understood as a driven base and has a second block 27 with a tube section 44 arranged thereon, which, analogous to the tube section 41 of the drive device 3, has a curved section (not shown here) for receiving and slidingly supporting the hollow sphere 10. The output device 4 comprises a connection plate 25, which is designed to connect further components of the robot 1 to the joint arrangement 2, in particular extensions of the robot arm 30 or the second robot arm segment 32, such as a robot hand or further end effectors.

[0045] The connection plate 25 is connected to an output shaft 28 in a form-fitting and rotationally fixed manner via a star lock 29, wherein the star lock 29 is arranged in accordance with the Fig. 9 and Fig. 10 is axially received in a complementary recess 45 on the connecting plate 25. The output shaft 28 is connected in a rotationally fixed manner to the second shaft 12 of the universal joint 9 for transmitting the input drive power. In addition, a second axial bearing 26 is provided that axially supports the connecting plate 25 on the second block 27 and mounts it rotatably therewith.

[0046] The mutually facing blocks 19, 27 of the drive device 3 and the output device 4 generally have identical or almost identical circular hole patterns. In the output device 4, the four larger holes 46 evenly distributed around the circumference of the second block 27 serve to attach the cable ends of the cables 7a, 7b, 8a, 8b of the second and third cable pulls 7, 8, respectively, while the other holes can perform other secondary functions not described in detail here. This hole pattern is transferred in the same or similar way to the drive device 3, the difference being that the larger holes 47 arranged on the first block 19 serve to axially guide the cables 7a, 7b, 8a, 8b of the second and third cable pulls 7, 8 between the second block 27 and the third block 34.The third block 34 of the drive device 3 also has bores 48 for axially guiding the cables 7a, 7b, 8a, 8b to the associated actuator 23, 24. The first and third blocks 19, 34 presently have six bores 47, 48 to additionally axially guide the deflected cables 6a, 6b of the first cable pull 6 to the associated actuator 22. The first and third blocks 19, 34 can also have additional bores that can perform other secondary functions not described in detail here.

[0047] The Fig. The second actuator 23 indicated in Fig. 3 is designed to actuate the cables 7a, 7b of the second cable pull 7 in such a way that the output device 4, guided by the ball joint 5, executes a pitching movement relative to the drive device 3, namely in order to Fig. 2. The y-axis shown in Fig. The third actuator 24 indicated in Figure 3 is designed to actuate the cables 8a, 8b of the third cable pull 8 in such a way that the output device 4, guided by the ball joint 5, carries out a yawing movement relative to the drive device 3, namely by the Fig. 2 x-axis shown.

[0048] To execute the pitching movement, the cables 7a, 7b of the second cable pull 7 are arranged on opposite sides of the hollow sphere 10 with respect to the hollow sphere 10. To execute the pitching movement, the cables 8a, 8b of the third cable pull 8 are arranged on opposite sides of the hollow sphere 10 with respect to the hollow sphere 10 and offset by 90° in the circumferential direction of the drive device 2 from the cables 7a, 7b of the second cable pull 7. The cables 7a, 7b, 8a, 8b of the second and third cable pulls 7, 8 are arranged alternately and evenly around the circumference of the hollow sphere 10 and are fastened or guided in the aforementioned bores 46, 47, 48. The cables 6a, 6b of the first cable pull 6 are arranged and guided in the circumferential direction between the first cable 7a of the second cable pull 7 and the first cable 8a of the third cable pull 8 or between the second cable 7b of the second cable pull 7 and the second cable 8b of the third cable pull 8, cf. Fig. 6.

[0049] The joint assembly 2 proposed and described here implements a so-called 3-DOF (3-degree-of-freedom) mechanism, which enables high flexibility, independent degrees of freedom, a compact design, and high torque and shear force carrying capacities. Such a joint assembly 2 can also be used in gear assemblies with high flexibility requirements, in flexible shafts, in the wrists or shoulders of robot arms, and in flexible robot bodies. List of reference symbols 1 robot 2 Joint arrangement 3 Drive device 4 Output device 5 ball joint 6 First rope pull 6a First rope of the first rope pull 6b Second rope of the first rope pull 7 Second cable pull 7a First rope of the second rope pull 7b Second rope of the second rope pull 8 Third cable pull 8a First rope of the third rope pull 8b Second rope of the third rope pull 9 Cardan joint 10 hollow spheres 11 First shaft of the cardan joint 12 Second shaft of the cardan joint 13 First recess of the hollow sphere 14 Second recess of the hollow sphere 15 Curved section 16 outer diameter of the hollow sphere 17 Drive pulley 18 First thrust bearing 19 First block of the drive device 20 First pulley 21 Second pulley 22 First actuator 23 Second actuator 24 Third actuator 25 Connection plate of the output device 26 Second thrust bearing 27 Second block of the output device 28 Output shaft of the output device 29 Star Lock 30 robot arm 31 First robot arm segment 32 Second robot arm segment 33 Center 34 Third Block 35 Drive shaft of the drive device 36 screw 37 Shaft of the pulley 38 roll 39 spacers 40 spacer sleeve 41 Pipe section of the drive device 42 mother 43 Hexagonal recess 44 Pipe section of the output device 45 Recess of the connection plate 46 Hole on the first block of the output device 47 Hole on the second block of the drive device 48 Hole on the third block of the drive device

Claims

[1] Joint arrangement (2) for a robot (1), comprising a drive device (3), an output device (4), a ball joint (5) connecting the two devices (3, 4) in an articulated manner, and a first cable (6), a second cable (7) and a third cable (8), wherein the cables (6, 7, 8) are separately operable, wherein the ball joint (5) has a hollow ball (10) with a universal joint (9) arranged therein, wherein the universal joint (9) comprises a first shaft (11) which is assigned to the drive device (3) and which can be driven in rotation, and a second output shaft (12) which is assigned to the output device (4), wherein the first cable (6) is designed to set a roll angle of the output device (4) relative to a center (33) of the hollow ball (10), wherein the second cable (7) is designed to set a pitch angle of the output device (4) relative to the center (33) of the hollow ball (10), and wherein the third cable (8) is designed toto set a yaw angle of the output device (4) relative to the center (33) of the hollow sphere (10), characterized by that each cable pull (6, 7, 8) has a first cable (6a, 7a, 8a) and a second cable (6b, 7b, 8b), wherein the cables (6a, 6b) of the first cable pulley (6) are wound on a cable pulley (17) of the drive device (3), wherein the cables (7a, 7b) of the second cable pull (7) are arranged on opposite sides with respect to the hollow sphere (10) and are guided axially on the drive device (3) and fastened to the output device (4), wherein the cables (8a, 8b) of the third cable pull (8) are arranged offset relative to the cables (7a, 7b) of the second cable pull (7) on opposite sides and in the circumferential direction of the drive device (2) with respect to the hollow sphere (10), and are guided axially on the drive device (3) and fastened to the output device (4), and wherein the cable pulley (17) is at least indirectly connected in a rotationally fixed manner to the first shaft (11) of the cardan joint (9) and is axially supported and rotatably mounted on a first block (19) of the drive device (3) via a first axial bearing (18). [2] Joint arrangement (2) according to claim 1, characterized by that the hollow ball (10) of the ball joint (5) has recesses (13, 14) for receiving and guiding the shafts (11, 12) of the cardan joint (9). [3] Joint arrangement (2) according to claim 1 or claim 2, characterized by that the drive device (3) and the output device (4) each have a curved section (15) with a radius which is complementary to the outer diameter (10). [4] Joint arrangement (2) according to claim 1, characterized bythat the first cable (6a) of the first cable pull (6) is deflected by a first deflection pulley (20) and the second cable (6b) of the first cable pull (6) is deflected by a second deflection pulley (21). [5] Joint arrangement (2) according to one of claims 1 to 4, characterized by that the cables (6a, 6b, 7a, 7b, 8a, 8b) of the respective cable pull (6, 7, 8) are operatively connected to an associated actuator (22, 23, 24) arranged on the drive device (3). [6] Joint arrangement (2) according to one of the preceding claims, characterized by that the output device (4) has a connecting plate (25) which is at least indirectly connected in a rotationally fixed manner to the second shaft (12) of the cardan joint (9) and is axially supported and rotatably mounted on a second block (27) of the output device (4) via a second axial bearing (26). [7] Joint arrangement (2) according to one of the preceding claims, characterized bythat the output device (4) comprises an output shaft (28) which is connected in a rotationally fixed manner to the second shaft (12) of the cardan joint (9), wherein the output shaft (28) is connected in a rotationally fixed manner to the connecting plate (25) via a star lock (29). [8] Robot (1) comprising at least one joint arrangement (2) according to one of the preceding claims.

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