industrial robot

Abstract

Industrial robot with parallel kinematics with a robot base (1), with a support element (2) for receiving a gripper, a tool or a machine element, with at least two movable actuation units (4) which are connected at one end to actuation unit drives (6) arranged on the robot base (1), and whose other end is movably connected to the carrier element (2), with a first rotary axis (13) which transmits a torque of a first rotary axis drive (14) arranged on the robot base (1) to a gripper, a tool or a machine element arranged on the support element (2), with a first joint (17) designed as a universal joint at the end of the first axis of rotation (13) facing the robot base (1), with a joint fork (22) which is arranged at the end of the first axis of rotation (13) facing the robot base (1), with a cross piece (18) of the first joint (17), which is equipped with a first pair of axle stubs (20) and a second pair of axle stubs (21), wherein the first axis defined by the first pair of axle stubs (20) and the second axis defined by the second pair of axle stubs (21) are substantially perpendicular to each other, wherein the first pair of axle stubs (20) is rotatably mounted in the joint fork (22), with a pulley (23) rotatably mounted on the robot base (1), which is connected to the first rotary axis drive (14) via a belt (24), wherein the second pair of axle stubs (21) is rotatably mounted in the pulley (23), with a second joint (28) with several degrees of freedom, via which the first axis of rotation (13) is movably connected to the support element (2), wherein the first joint (17), the first axis of rotation (13) and the second joint (28) each have a continuous cavity, and the cavities of the first joint (17), the first axis of rotation (13) and the second joint (28) form a continuous channel from the robot base (1) to the support element (2), and wherein a second rotary axis (27) designed as a cardan shaft is arranged in the continuous channel, and the second rotary axis is driven to rotation by a second rotary axis drive (29) arranged on the robot base (1), wherein the second rotary axis (27) transmits a torque of the second rotary axis drive (29) to the gripper, the tool or the machine element on the carrier element (2).

Description

[0001] The invention is based on an industrial robot with parallel kinematics, which is equipped with a robot base, with a carrier element serving as a holder for a gripper or a tool and with several actuating units for moving the carrier element.

[0002] Such industrial robots with parallel kinematics are used to move, position and / or process an object in space. They are equipped with a stationary robot base and a movable support element for holding a gripper, a tool or a machine element. At least two actuating units are connected at one end to the robot base and at the other end to the support element. Each actuating element is moved via an associated drive arranged on the robot base. A movement of the actuating units leads to a movement of the support element. For example, a gripper for picking up an object or a tool for processing an object or a machine element such as a bearing or a gear can be arranged on the support element. For this purpose, the support element is equipped with a holder for a gripper, a tool or a machine element.Through the coordinated movement of the driven actuating units, the gripper, tool or machine element arranged on the support element can be moved in a targeted manner in several dimensions in space. The actuating arms ensure spatial parallelogram guidance of the support element. The resulting parallel kinematics enables fast and precise movement of the support element and the gripper, tool or machine element arranged on it. This movement is a translational movement of the support element. If the industrial robot is equipped with three actuating units, this is a translational movement in three spatial directions. The movement has three degrees of freedom and can be described in a coordinate system with x, y and z axes. If the industrial robot is equipped with two actuating units, this is a translational movement in two spatial directions.In this case, the movement has two degrees of freedom and can be described in a coordinate system with x and z axes. In addition to this translational movement of the support element, a further drive on the robot base can generate a torque and transfer it to a gripper, tool or machine element arranged on the support element. This is a rotational movement and therefore represents a further degree of freedom. This movement is not used to position the gripper, tool or machine element in space, but to move the gripper, tool or machine element itself, for example, opening and closing the gripper or rotating the tool or machine element. If the industrial robot is equipped with three control arms, a rotational axis that transfers the torque from the drive to a gripper, tool or machine element on the support element is referred to as the fourth axis.

[0003] Such robots include, for example, delta robots. These are equipped with at least two control arms as actuating units. The actuating or control arms have an upper and a lower arm section, which are movably connected to one another. Each of the upper arm sections is driven by an actuating arm drive, for example a motor-gear unit. The drives are arranged on the robot base. The movement of the upper arm sections is transmitted to the support element via the lower arm sections. Each lower arm section has two parallel rods or struts running in the longitudinal direction of the arm section, which are movably connected at one end to the associated upper arm section and at the other end to the support element.

[0004] In addition to delta robots, cable robots are also classified as industrial robots with parallel kinematics. Cable robots are equipped with cables as actuating units. Each cable is connected to a drive at one end. The drives are designed as rotary or linear drives, which specify the free length of the cables by winding and unwinding them onto a shaft connected to one end of the cable, or by pushing a push rod connected to one end of the cable back and forth. At the end facing away from the drive, the cables are connected to a support element for a gripper or tool. Care must be taken to ensure that the cables are taut. Through the coordinated movement of the drives, the gripper or tool arranged on the support element can be moved precisely in several dimensions.

[0005] A gripper, tool, or machine element arranged on the support element can additionally be actuated via a pneumatic, hydraulic, or electric drive. In addition, sensors for monitoring and controlling the gripper, tool, or machine element can be arranged on the support element. For this purpose, hydraulic, pneumatic, electrical, or optical supply lines are routed from the robot base to the support element. The supply lines transport compressed air, hydraulic fluid, electrical current, or light. Light may, for example, be necessary for a sensor arranged on the gripper or tool. The supply lines connect the robot base to the support element freely and without guidance, or they are routed along the actuation units or the transmission device.

[0006] Such an industrial robot with actuating units in the form of control arms is known, for example, from EP 250 470 A1.

[0007] DE 10 2010 033 429 A1 discloses a delta robot suitable for use in food production and processing. It has three control arms and a torque transmission device for transmitting torque to a tool. The torque transmission device has at least two telescopically movable tubes through which the supply lines run.

[0008] DE 10 2010 006 155 A1 discloses a parallel robot with three arms and a rod-shaped transmission element for transmitting torque from the drive motor to a tool arranged on the wrist section. The drive mechanism for the wrist section comprises a hollow outer holder, a middle holder, and an inner holder, each of which is rotatable about orthogonal axes.

[0009] DE 10 2008 023 069 A1 discloses a handling device for positioning products. It comprises a movable handling element, for example, a gripper or a suction cup, with a fixed-position drive and a connecting element that transmits the torque of the drive to the handling element. The connecting element protrudes from the first bearing on the side opposite the longitudinal extension effective for rotational transmission, so that it is guided through it like a push rod.

[0010] DE 10 2008 019 725 A1 discloses a delta robot with a base plate on which four servo drives are mounted. Three of the four servo drives are each connected to a swivel arm, which is articulated to rods that are articulated to a motion plate. The fourth servo drive is connected via a universal joint to a two-part telescopic axis consisting of a hollow torsion outer beam and a torsion core beam that can be telescopically inserted into it.

[0011] DE 699 27 704 T2 discloses an industrial robot based on the delta concept with a spatially rotatable arm system consisting of a base station, a movable plate, several multi-jointed connecting rods, and a telescopic axis arranged between the base section and the movable plate. Opposite ends of the connecting rods and the telescopic axis are connected to the base section and the movable plate, respectively. The telescopic axis consists of an inner axis and an outer tube arranged longitudinally displaceably on the inner axis, in which a torsionally rigid sleeve is fixedly arranged.

[0012] WO 2008 / 122 721 A2 discloses a parallel motion device with at least three pivot arms. An actuator is provided at each first end of each pivot arm, and connecting elements are provided at each second end of each pivot arm to ensure a connection to the head. Furthermore, a gripper is provided, the free end of which is slidably guided in a joint guide and the other end of which is connected to the head via a universal joint. The gripper is designed as a telescopic gear with two interlocking rods and is protected by a sleeve. The joint guide consists of concentric rings.

[0013] Known industrial robots with parallel kinematics have the disadvantage that a rotation axis, which transmits torque from a rotation axis drive on the robot base to the support element, is movably connected to the robot base via a joint with multiple degrees of freedom. Such joints with multiple degrees of freedom typically require a lot of space. Since the distance between the robot base and the support element is determined by the location of the industrial robot, extending the joint in the axial direction leads to a corresponding reduction in the axial length of the rotation axis. The shorter the rotation axis, the larger the angle of the cone within which the rotation axis moves when the support element is deflected by the actuating units.

[0014] The invention is based on the object of providing an industrial robot with parallel kinematics in which the joint via which the rotation axes are connected to the robot base has a small structural dimension.

[0015] This object is achieved by an industrial robot having the features of claim 1. It is characterized in that the joint of the first rotational axis near the robot base, referred to as the first joint, is a universal joint. It has a crosspiece with a first pair of stub axles and a second pair of stub axles. The axes defined by the two pairs of stub axles are essentially perpendicular to one another. They preferably intersect. The first pair of stub axles is rotatably mounted in a joint fork. The joint fork is arranged at the end of the first rotational axis facing the robot base. The second pair of stub axles is rotatably mounted in a belt pulley. The belt pulley, in turn, is rotatably mounted on the robot base. It is connected by a belt to a rotational axis drive of the first rotational axis.The cross piece is located inside the pulley, which is equipped with a recess extending in the axial direction.

[0016] The pulley is part of the belt drive that transfers the torque of the rotary axis drive to the first rotary axis. In addition to the pulley, the belt drive includes a belt that runs on a running surface of the pulley. The pulley has an axle stub that is rotatably mounted in a bearing on the robot base.

[0017] Because the crosspiece of the universal joint is located in the pulley, which is connected to the rotary axis drive by a belt, the first joint requires significantly less space in the axial direction than corresponding joints of conventional industrial robots with parallel kinematics. This allows the joint, together with the pulley, to be characterized by a compact design.

[0018] Further advantages and advantageous embodiments of the invention are contained in the following description, the drawings and the claims. drawing

[0019] The drawing illustrates an embodiment of the invention and describes it in more detail below. It shows: Fig. 1 Industrial robot with parallel kinematics in a first perspective view, Fig. 2 industrial robots according to Fig. 1 in a second perspective view, Fig. 3 industrial robots according to Fig. 1 in a third perspective view, Fig. 4 industrial robots according to Fig. 1 in a perspective view from above, Fig. 5 first joint of the industrial robot according to Fig. 1 in a view from below, Fig. 6 industrial robots according to Fig. 1 in a view from above, marking the section planes A - A and B - B, Fig. 7 Section through the industrial robot according to Fig. 1 along the Fig. 6 specified section plane A - A, Fig. 8 Section through the industrial robot according to Fig. 1 along the Fig. 6 specified section plane B - B, Fig. 9 Excerpt from Fig. 7, Fig. 10 Excerpt from Fig. 8. Description of the embodiment

[0020] In the Fig. 1 to 10 show an industrial robot with parallel kinematics based on the delta principle, comprising a robot base 1, a support element 2 on which a gripper, a tool, or a machine element can be arranged, and three actuating units 4 designed as control arms. The gripper, the tool, or the machine element are not shown in the drawing. Each of the three actuating units is connected via a drive shaft to an actuating unit drive 6 designed as a motor. All three actuating units 4 have the same structure. The actuating units 4 have an upper arm section 7 and a lower arm section 8. The upper arm section 7 is characterized by high stability and low weight. The lower arm section 8 has two parallel rods 9 and 10.The two rods 9 and 10 of the lower arm section 8 of an actuating unit 4 are connected via joints 11 at their upper end to the upper arm section 7 of the actuating unit 4 and via joints 12 to the support element 2.

[0021] The industrial robot is further equipped with a first rotary axis 13 designed as a hollow body. It serves to transmit a torque of a first rotary axis drive 14 arranged on the robot base 1 to a gripper (not shown in the drawing) or a tool or machine element (not shown) on the support element. The first rotary axis 13 has two telescopically arranged tubes 15 and 16 that can be moved one inside the other. Due to the movable mounting, changes in the distance between the robot base 1 and the support element 2 can be compensated during a movement of the actuating units 4. The upper tube 16 is movably connected to the robot base 1 via a first joint 17. The first joint is particularly well suited to Fig. 5, Fig. 9 and Fig. 10. This is a cardan joint or universal joint. The first joint 17 has a cross piece 18 which is equipped with a ring 19. A first pair of stub axles 20 and a second pair of stub axles 21 are arranged on the ring 19. The two axes defined by the pairs of stub axles 20, 21 intersect at right angles. The first pair of stub axles 20 is rotatably mounted in a joint fork 22 which is arranged on the first axis of rotation 13. The second pair of stub axles 21 is rotatably mounted in a pulley 23. The pulley 23 is connected to the first axis of rotation drive 14 via a belt 24. Furthermore, the pulley 23 is rotatably mounted on the robot base 1. A torque of the first axis of rotation drive 14 is transmitted to the pulley 23 via the belt 24. The pulley 23 and the belt 24 are part of a belt drive that transmits the torque of the rotary axis drive 14 to the first rotary axis.The pulley 23 has a recess and is hollow inside. Two bearings 25, 26 are provided on the inside of the pulley. The second pair of axle stubs 21 is rotatably mounted in these bearings 25, 26.

[0022] The pulley 23 is designed as a toothed belt pulley. The belt 24 is designed as a toothed belt.

[0023] The first joint 17 and the first rotation axis 13 have a continuous cavity through which a second rotation axis 27, designed as a cardan shaft, extends. The continuous cavity can also be referred to as a channel. The second rotation axis 27 is driven by a second rotation axis drive 29. It extends through the first rotation axis 13 to the side of the support element 2 facing away from the robot base 1. Fig.2 shows an end of the second rotation axis 27 designed as a shaft stub, which can be connected to a gripper, tool or machine element arranged on the carrier element.

[0024] The lower tube 15 of the first rotation axis 13 is movably connected to the support element 2 via a second joint 28 designed as a universal joint. The two joints 17, 23 allow the length-adjustable first rotation axis 13 to follow a deflection of the support element 2 relative to the robot base 1.

[0025] All features of the invention can be essential to the invention both individually and in any combination with one another. Reference numbers 1 robot base 2 support element 3 4 Actuating unit 5 6 Actuator drive 7 upper arm section 8 lower arm section 9 rods 10 bars 11 Joint 12 joint 13 first axis of rotation 14 first rotary axis drive 15 pipe 16 pipe 17 first joint 18 Crosspiece 19 rings 20 First pair of axle stumps 21 Second pair of axle stub 22 Joint fork 23 Pulley 24 belts 25 warehouses 26 warehouses 27 Second axis of rotation 28 Second joint 29 Second rotary axis drive 30 shaft stubs

Claims

[1] Industrial robots with parallel kinematics with a robot base (1), with a carrier element (2) for receiving a gripper, a tool or a machine element, with at least two movable actuating units (4), one end of which is connected to actuating unit drives (6) arranged on the robot base (1), and the other end of which is movably connected to the support element (2), with a first rotational axis (13) which transmits a torque of a first rotational axis drive (14) arranged on the robot base (1) to a gripper, a tool or a machine element arranged on the carrier element (2), with a first joint (17) designed as a universal joint at the end of the first axis of rotation (13) facing the robot base (1), with a joint fork (22) which is arranged at the end of the first rotation axis (13) facing the robot base (1), with a crosspiece (18) of the first joint (17), which is equipped with a first pair of axle stub (20) and a second pair of axle stub (21), wherein the first axis defined by the first pair of axle stub (20) and the second axis defined by the second pair of axle stub (21) are substantially perpendicular to each other, wherein the first pair of axle stub (20) is rotatably mounted in the joint fork (22), with a pulley (23) rotatably mounted on the robot base (1), which is connected to the first rotary axis drive (14) via a belt (24), wherein the second pair of axle stubs (21) is rotatably mounted in the pulley (23), with a second joint (28) with several degrees of freedom, via which the first axis of rotation (13) is movably connected to the support element (2), wherein the first joint (17), the first rotation axis (13) and the second joint (28) each have a continuous hollow space, and the hollow spaces of the first joint (17), the first rotation axis (13) and the second joint (28) form a continuous channel from the robot base (1) to the support element (2), and wherein a second rotational axis (27) designed as a cardan shaft is arranged in the continuous channel, and the second rotational axis is driven for rotation by a second rotational axis drive (29) arranged on the robot base (1), wherein the second rotational axis (27) transmits a torque of the second rotational axis drive (29) to the gripper, the tool or the machine element on the carrier element (2). [2] Industrial robot according to claim 1, characterized by that the pulley (23) has a recess, and that the cross piece (18) is arranged within the recess. [3] Industrial robot according to claim 1 or 2, characterized by that the joint fork (22) is arranged at least in sections within the pulley (23). [4] Industrial robot according to claim 1, 2 or 3, characterized by that the first axis defined by the first pair of axle stub (20) intersects the axis of the pulley (23), and that the second axis defined by the second pair of axle stub (21) intersects the axis of the pulley (23). [5] Industrial robot according to one of the preceding claims, characterized by that the drive axis of the first rotary axis drive (14) and the axis of the pulley (23) are substantially perpendicular to each other. [6] Industrial robot according to one of the preceding claims, characterized by that the first rotary axis drive (14) is located below the robot base (1). [7] Industrial robot according to one of the preceding claims, characterized bythat the pulley (23) is designed as a toothed belt pulley, and that the belt (24) is designed as a toothed belt. [8] Industrial robot according to one of the preceding claims, characterized by that the cross piece (18) has a ring (19) on which the first pair of axle stubs (20) and the second pair of axle stubs (21) are arranged. [9] Industrial robot according to one of the preceding claims, characterized by that supply lines for a gripper, a tool or a machine element arranged on the carrier element are arranged in the continuous channel. [10] Industrial robot according to one of the preceding claims, characterized by that the actuating units (4) are designed as arms with an upper arm section (7) which is coupled to a respective actuating unit drive (6), and with a lower arm section (8) rotatably connected to the upper arm section (7).

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