Axis limiting device for mechanically limiting the maximum angle of rotation at a rotary joint of a robot arm and robot arm with such an axis limiting device

Abstract

Axis limiting device for mechanically limiting the maximum angle of rotation at a rotary joint which directly connects a first member (G1) to a second member (G2), comprising: - a movable stop body (16) with a foot section (16a) and a head section (16b), - a first guide member (F1) connectable to the first member (G1) or formed thereon, which has a first groove (17.1) with a first groove track (17a) which is designed for adjustably supporting the foot section (16a) of the stop body (16) along the first groove track (17a) and for limitingly supporting the foot section (16a) of the stop body (16) transversely to the first groove track (17a), - a second guide member (F2) which can be connected to the second member (G2) or is formed thereon and which has a guide surface on which a second groove (17.2) is formed, which has a second groove track (17b) which extends circumferentially around an axis of rotation (D) by more than 360 degrees, wherein the second groove (17.2) is designed for the adjustable mounting of the head section (16b) of the stop body (16) along the second groove track (17b) and for the limiting mounting of the head section (16b) of the stop body (16) transversely to the second groove track (17b), wherein - the first guide member (F1) and the second guide member (F2) are arranged relative to one another in such a way that the stop body (16) simultaneously engages with its foot section (16a) in the first groove (17.1) of the first member (G1) and with its head section (16b) in the second groove (17.2) of the second member (G2), so that when the first guide member (F1) rotates relative to the second guide member (F2) about the axis of rotation (D), the stop body (16) moves both through the first groove track (17a) of the first groove (17.1) and also moves circumferentially about the axis of rotation (D) through the second groove track (17b) of the second groove (17.2).

Description

[0001] The invention relates to an axis limiting device for mechanically limiting the maximum angle of rotation at a rotary joint that directly connects a first member to a second member. The invention also relates to a robot arm with such an axis limiting device.

[0002] EP 2 301 725 B1 describes an industrial robot comprising a multi-axis robot arm with a frame, a carousel mounted so as to be rotatable relative to the frame with respect to an axis, and a mechanical stop device provided for limiting a rotational movement of the carousel relative to the frame, said stop device comprising a guide arranged on the frame with stops arranged at its ends, a trailing stop arranged in the guide, and a driver arranged on the carousel, wherein the driver and the guide are designed such that the driver is inserted into the guide during a corresponding rotational movement of the carousel with respect to the axis and pushes the trailing stop against the relevant stop, and the trailing stop comprises a plastically deformable damping element which is provided, due to a plastic deformation caused by the trailing stop being pushed against the relevant stop by the driver,to slow down the carousel.

[0003] The object of the invention is to provide an axis limiting device and a robot arm with such an axis limiting device which can mechanically limit a maximum angle of rotation greater than 360 degrees using simple and reliably operable means.

[0004] Known axis limiting devices, which can mechanically limit a maximum rotation angle greater than 360 degrees, usually operate with so-called movable drag stops. Such drag stops are separate, movably mounted components that can be adjusted over a specified angular range. When a corresponding swivel joint rotates, for example, by more than 180 degrees clockwise, a stop body of one rotating link strikes the drag stop upon reaching the 180-degree position and displaces it by the specified angular range on the other link until the specified drag stop strikes the end of the thus extended angular range, thus mechanically limiting the maximum clockwise rotation angle to an angle of more than 180 degrees.When the swivel joint rotates more than 180 degrees counterclockwise, a stop body on the opposite side of the trailing stop engages and shifts it by the specified angular range on the other link to the other end of the extended angular range, where the trailing stop then engages. However, the separate design of the trailing stop and its movable bearing within the extended angular range is a disadvantage. This not only leads to loud noises when the stop body strikes the movable trailing stop, but also leads to significant wear and an increased risk of damage and downtime.In addition, the known drag stops can only move over a specified angular range that is significantly smaller than 360 degrees, and in most cases even smaller than 180 degrees, so that it is not possible, for example, to construct axis limitations with known drag stops that allow a maximum angle of rotation of more than 720 degrees.

[0005] The object is achieved by an axis limiting device for mechanically limiting the maximum angle of rotation at a rotary joint which directly rotatably connects a first member to a second member, comprising: - a movable stop body with a foot section and a head section, - a first guide member connectable to the first member or formed thereon, which has a first groove with a first groove path, which is designed for adjustably supporting the foot portion of the stop body along the first groove path and for limitingly supporting the foot portion of the stop body transversely to the first groove path, - a second guide member connectable to the second member or formed thereon, which has a guide surface on which a second groove is formed, which has a second groove path extending circumferentially around a rotation axis by more than 360 degrees, wherein the second groove is designed for adjustably supporting the head portion of the stop body along the second groove path and for limitingly supporting the head portion of the stop body transversely to the second groove path, wherein - the first guide member and the second guide member are arranged relative to one another in such a way that the stop body simultaneously engages with its foot section in the first groove of the first member and with its head section in the second groove of the second member, so that when the first guide member rotates relative to the second guide member about the axis of rotation, the stop body moves both through the first groove path of the first groove and also moves circumferentially through the second groove path of the second groove about the axis of rotation.

[0006] The axle limiting device according to the invention thus has two different grooves, namely a first groove with a first groove path in the first guide member of the axle limiting device and a second groove with a second groove path in the second guide member of the axle limiting device.

[0007] The movable stop body is guided in both the first groove and the second groove. For this purpose, the movable stop body has a foot section, which guides it within the first groove path of the first groove, and the movable stop body has a head section, which guides it within the second groove path of the second groove.

[0008] Across the entire maximum angle of rotation, the first groove path of the first groove runs at least substantially perpendicular to the second groove path of the second groove. The first groove can in particular have a straight first groove path. The second groove path, on the other hand, has an at least substantially spiral-shaped second groove path or a helical second groove path. Due to a spiral or helical design of the second groove path, a second groove can be created which can in particular also rotate around the axis of rotation by at least two complete revolutions of 360 degrees each. In this way, an axis limiting device can be realized which permits a maximum angle of rotation of more than 720 degrees, if desired.Of course, even with the use of such an axis limiting device, the maximum angle of rotation can still be limited to less than 720 degrees, for example, by inserting stopper inserts into the second groove, which are described in more detail below. However, the option of expanding the maximum angle of rotation to more than 720 degrees remains.

[0009] Because the movable stop body is always guided in both the first groove and the second groove simultaneously, the stop body is guided in contact with both the first guide member and the second guide member in every angular position of the pivot joint. Consequently, the axle limiting device according to the invention does not have a drag stop body that would be freely movable in one of the grooves. In this respect, striking against a freely movable drag stop body cannot occur with the axle limiting device according to the invention. This not only prevents the otherwise possible loud noise when the stop body strikes a movable drag stop, but also avoids excessive wear and an increased risk of damage and operational failures. With the axle limiting device according to the invention, no moving component collides with another stationary component at high speed.Rather, the movable stop body according to the invention is always in contact engagement with both the first guide member and the second guide member.

[0010] In a first embodiment, the first groove can have a first groove track extending at least substantially radially to the axis of rotation, which is designed for radially adjustably supporting the foot section of the stop body along the first groove track and for limitingly supporting the foot section of the stop body in a circumferential direction around the axis of rotation, wherein the guide surface extends perpendicular to the axis of rotation, and at least a first groove track section of the second groove extends on an inner annular surface section of the guide surface and at least a second groove track section of the second groove extends on an outer annular surface section of the guide surface that is different from the inner annular surface section, wherein the second groove is designed for adjustably supporting the head section of the stop body along the second groove track and for limitingly supporting the head section of the stop body in the radial direction to the axis of rotation.

[0011] The first guide member is arranged with respect to the second guide member such that the first opening of the first groove and the second opening of the second groove are oriented towards one another. Accordingly, the stop body can simultaneously engage in the first groove track of the first groove and in the second groove track of the second groove. The stop body is loosely inserted between the first groove and the second groove. The stop body is guided on the one hand by the opposite first groove side walls of the first groove and on the other hand by the opposite second groove side walls of the second groove and is held in position. The foot section of the stop body can be guided in the first groove either with a sliding bearing or with a rolling bearing. The head section of the stop body can be guided in the second groove in a similar manner, either with a sliding bearing or with a rolling bearing.

[0012] The second groove path can, in particular, have a spiral shape. This means that in such an embodiment, the second groove revolves multiple times, i.e., at least twice, around a center point located on the axis of rotation, and the radial distance of the second groove from the center point changes continuously. The second groove always lies in the same plane, which runs perpendicular to the axis of rotation.

[0013] Instead of a spiral course, in a modified embodiment the second groove can extend by slightly less than 360 degrees, for example by 315 degrees, on a first circular path with a constant first radius around the axis of rotation and shortly before reaching one end of the second groove the second groove path leads radially in an arc from the first circular path with a constant first radius into a second circular path with a constant second radius different from the first radius, so that the stop body guided therein can switch from one circular path section to the other circular path section like a switch. The second groove can therefore have a plurality of approximately completely circumferential circular annular groove sections, of which two adjacent circular annular groove sections are connected by a short arc to form a continuous, multi-circumferential second groove.

[0014] In a further development of the first embodiment, the second guide member can be designed as a circular disc, one disc surface of which forms the guide surface in which the second groove is introduced.

[0015] The circular disc can have a center point located on the axis of rotation. The disc surface lies in a plane extending perpendicular to the axis of rotation. The second groove then extends in the disc surface, particularly in a spiral design or in a multiple concentric design with curved paths.

[0016] In a second embodiment, the first groove may have a first groove path extending at least substantially parallel to the axis of rotation, which is designed for adjustably supporting the foot portion of the stop body along the first groove path parallel to the axis of rotation and for limitingly supporting the foot portion of the stop body in a circumferential direction around the axis of rotation, wherein the guide surface is an inner cylinder wall extending concentrically to the axis of rotation, and at least a first groove path portion of the second groove extends on an upper cylinder surface portion of the inner cylinder wall and at least a second groove path portion of the second groove extends on a lower cylinder surface portion of the guide surface different from the upper cylinder surface portion,wherein the second groove is designed for adjustably supporting the head portion of the stop body along the second groove path and for limiting the support of the head portion of the stop body in a direction parallel to the axis of rotation.,

[0017] In this second embodiment, too, the first guide member is arranged with respect to the second guide member such that the first opening of the first groove and the second opening of the second groove are oriented towards one another. Accordingly, the stop body can simultaneously engage in the first groove track of the first groove and in the second groove track of the second groove. The stop body is loosely inserted between the first groove and the second groove. The stop body is guided on the one hand by the opposite first groove side walls of the first groove and on the other hand by the opposite second groove side walls of the second groove and is held in position. The foot section of the stop body can be guided in the first groove either with a sliding bearing or with a rolling bearing. The head section of the stop body can be guided in the second groove in a similar manner, either with a sliding bearing or with a rolling bearing.

[0018] In the second embodiment, the second groove path can in particular have a helical course. This means that in such an embodiment, the second groove is formed on a circular cylinder jacket wall whose axis of rotation lies on the axis of rotation. The second groove thus screws itself forward in a thread-like manner parallel to the axis of rotation in an axial direction. The second groove can thus realize two or more complete thread revolutions. The circular cylinder jacket wall can generally be designed either as an inner cylinder jacket wall or an outer cylinder jacket wall. The first groove can have a straight course. The first groove can in particular extend parallel to the axis of rotation. In this case, the stop body moves in the first groove parallel to the axis of rotation in the axial direction of the axis of rotation.

[0019] In a further development of the second embodiment, the second guide member can be designed as a hollow circular cylindrical pipe section, the inner cylinder wall of which forms the guide surface in which the second groove is introduced.

[0020] The hollow cylindrical pipe section lies with its rotational axis on the rotational axis. The number of complete revolutions of the second groove on the inner cylinder wall determines the required axial height of the hollow cylindrical pipe section.

[0021] In both embodiments, the second groove can have a first counter stop surface for the stop body at one end of the second groove track to limit the angle of rotation in one direction of rotation and a second counter stop surface for the stop body at the other end of the second groove track to limit the angle of rotation in the opposite direction of rotation.

[0022] The head portion of the stop body is guided in the second groove. If the head portion has a circular-cylindrical cross-section, the first counter-stop surface and / or the second counter-stop surface can have a concave semicircular-cylindrical shape that matches the circular-cylindrical cross-section of the head portion.

[0023] The first counter-stop surface of the second groove may have a first spring device which is designed to cushion an impact of the stop body on the first counter-stop surface, and / or the second counter-stop surface of the second groove may have a second spring device which is designed to cushion an impact of the stop body on the second counter-stop surface.

[0024] The first spring device and / or the second spring device can be formed, for example, by a rubber-like coating or support.

[0025] The respective axis limiting device can have at least one stopper insert part which is designed for the detachable and / or adjustable insertion of the stopper insert part into the second groove at a point of the second groove track lying between one end of the second groove track and the other end of the second groove track, wherein the stopper insert part forms a third counter stop surface for the stop body on its side facing the stop body.

[0026] Using such a stopper insert, the actual effective maximum angle of rotation can be reduced compared to the maximum angle of rotation without a stopper insert. With a second groove without a stopper insert, the maximum angle of rotation is determined by one end of the second groove and the other end of the second groove. This maximum groove length can be shortened by inserting one or two stopper inserts into the second groove. This then results in a reduced effective maximum angle of rotation for the axis limiting device.

[0027] The stopper insert can, for example, be clamped or spread into the second groove. Alternatively, the stopper insert can also be formed by a screw or a threaded shaft of the screw, which can be screwed radially into the groove path of the second groove via a lateral hole.

[0028] The third counter-stop surface of the stopper insert can have a third spring device configured to cushion the impact of the stop body against the third counter-stop surface. The third spring device can be formed, for example, by a rubber-like coating or support on the stopper insert.

[0029] In addition, in all versions of the second groove, a second position measuring system can be assigned, which is designed and configured to detect the position of the stop body at its current location on the second groove path.

[0030] The term "second" position measuring system is used to express the assignment of the position measuring system to the second groove. Therefore, in certain design variants, the "second" position measuring system can also be provided as the sole position measuring system. The term "second" position measuring system also serves to clarify the distinction from the "first" position measuring system, described in more detail below, which is assigned to the first groove. Therefore, in certain design variants, the "first" position measuring system can be provided as the sole position measuring system as an alternative to the "second" position measuring system, or the "first" position measuring system can be implemented together with the "second" position measuring system on the axle limiting device.

[0031] The second position measuring system can be an absolute position measuring system. The second position measuring system can detect the position of the stop body on the second groove track, for example, using optical, magnetic, capacitive, or resistive sensors.

[0032] In all embodiments, the first groove can have a first counter surface for the stop body at one end of the first groove track to limit the angle of rotation in one direction of rotation and a second counter surface for the stop body at the other end of the first groove track to limit the angle of rotation in the opposite direction of rotation.

[0033] The base section of the stop body is guided in the first groove. If the base section has a rectangular or square cross-section, the first counter stop surface and / or the second counter stop surface can have a flat shape matching the base section.

[0034] The first counter surface of the first groove may have a first spring device which is designed to cushion an impact of the stop body on the first counter surface, and / or the second counter surface of the first groove may have a second spring device which is designed to cushion an impact of the stop body on the second counter surface.

[0035] The first spring device and / or the second spring device can be formed, for example, by a rubber-like coating or support.

[0036] The respective axis limiting device can have at least one stopper element which is designed for the detachable and / or adjustable insertion of the stopper element into the first groove at a point of the first groove track lying between one end of the first groove track and the other end of the first groove track, wherein the stopper element forms a third counter surface for the stop body on its side facing the stop body.

[0037] Using such a stopper element, the actual maximum effective angle of rotation can be reduced compared to the maximum angle of rotation without a stopper element. With a first groove without a stopper element, the maximum angle of rotation is determined by one end of the first groove and the other end of the first groove. This maximum groove length can be shortened by inserting one or two stopper elements into the first groove. This then results in a reduced effective maximum angle of rotation for the axis limiting device.

[0038] A sensor, in particular an electrical switching means, can be assigned to the respective stopper element and / or each end of the first groove, which can electrically detect contact or at least direct approach of the stop body to the stopper element and / or the respective end of the first groove and transmit this to a control unit, wherein the control unit can be configured to stop a driven rotation of the rotary joint if the sensor or the electrical switching means sends a corresponding signal. In this respect, a so-called software stop can be implemented, which, when the end position with the stop body in the first groove is reached, causes the rotation of the rotary joint to stop through control technology. In such a case, the stopping of the rotary joint is no longer dependent on a mechanically acting lock at the end of the groove.

[0039] The stopper element can, for example, be clamped or spread into the first groove. Alternatively, the stopper element can also be formed by a screw or a threaded shaft of the screw, which can be screwed radially into the groove path of the first groove via a lateral hole.

[0040] The third counter surface of the stopper element can have a third spring device configured to cushion the impact of the stop body against the third counter surface. The third spring device can be formed, for example, by a rubber-like coating or support on the stopper element.

[0041] In addition, in all embodiments, a first position measuring system can be assigned to the first groove, which is designed and configured to detect the position of the stop body at its current location on the first groove path.

[0042] The term "first" position measuring system is used to express the assignment of the position measuring system to the first groove. Therefore, in certain design variants, the "first" position measuring system can also be provided as the sole position measuring system. The term "first" position measuring system also serves to clarify the distinction from the previously described "second" position measuring system, which is assigned to the second groove. Therefore, in certain design variants, the "first" position measuring system can be provided as the sole position measuring system as an alternative to the "second" position measuring system, or the "first" position measuring system can be implemented together with the "second" position measuring system on the axle limiting device.

[0043] The first position measuring system can be an absolute position measuring system. The first position measuring system can detect the position of the stop body on the first groove path, for example, using optical, magnetic, capacitive, or resistive sensors.

[0044] In all versions, the stop body can be rigid.

[0045] The head section of the stop body and / or the foot section of the stop body can be provided with a spring-elastic jacket on its respective outer jacket wall.

[0046] The stop body can generally be designed as a pin, one half of which forms the head section of the stop body and the other half of which forms the foot section.

[0047] The head portion may be formed as a pin portion having a circular cylindrical cross section and the foot portion may be formed as a pin portion having a rectangular or square cross section.

[0048] If the head section is designed as a pin section with a circular cylindrical cross-section, it can slide smoothly through the second groove path. Designing the foot section as a pin section with a rectangular or square cross-section ensures a torsion-proof mounting of the stop body in the first groove.

[0049] The object is also achieved by a robot arm with a plurality of links and joints which adjust the links relative to one another, of which at least one joint is designed as a rotary joint which connects a first link of the robot arm to an immediately adjacent second link of the robot arm in a manner which can rotate relative to one another, wherein the rotary joint has an axis limiting device according to one of the described embodiments.

[0050] In general, an axis limiting device according to the invention can be provided on any rotational axis of a robot arm. In a specific embodiment, the axis limiting device according to the invention can preferably be provided on the first axis of the kinematic chain of the robot arm, i.e., on the pivot joint that rotatably connects a base frame of the robot arm to a carousel of the robot arm.

[0051] In a first variant, the first guide member of the axis limiting device can be designed as a component separate from the first member of the robot arm and fastened to the first member of the robot arm and / or the second guide member of the axis limiting device can be designed as a component separate from the second member of the robot arm and fastened to the second member of the robot arm.

[0052] By designing the first guide member of the axis limiting device as a separate component from the first member of the robot arm and / or by designing the second guide member of the axis limiting device as a separate component from the second member of the robot arm, the entire axis limiting device can be manufactured separately from the robot arm. If necessary, an axis limiting device according to the invention can also be retrofitted to a robot arm.

[0053] Alternatively, in a second variant, the first guide member of the axis limiting device can be formed as a one-piece component together with the first member of the robot arm and / or the second guide member of the axis limiting device can be formed as a one-piece component together with the second member of the robot arm.

[0054] In this design variant, the axis limiting device is integrated into the robot arm during manufacture. This can be particularly useful if the robot arm is designed as a lightweight robot that should have the lowest possible weight.

[0055] 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.

[0056] They show: Fig. 1 a perspective view of an exemplary robot arm in the manner of an industrial robot, Fig. 2 a plan view of an exemplary axle limiting device according to the invention in a stand-alone position, Fig. 3 a lateral sectional view of the axle limiting device according to Fig. 2, Fig. 4 a perspective view of the axle limiting device according to Fig. 2, Fig. 5 a modified perspective view of the axle limiting device according to Fig. 2 with representation of hidden lines, so that the first groove path is recognizable, Fig. 6 to 11 several schematic representations of the axle limiting device from above, each in a rotation angle position progressively changed by 180 degrees, Fig. 12 an exemplary stop body with a head section with a circular cylindrical cross section and a foot section with a rectangular or square cross section in a unique position, and Fig. 13 a perspective view of a modified robot arm in the style of a lightweight robot.

[0057] The Fig. 1 shows an exemplary robot 1 in the form of an industrial robot 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 8 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 8 carries an arm boom 9, 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 9, whose base arm 10 forms a fourth link G4, a fourth axis A4 is provided, which runs in the longitudinal extension of the arm extension 9 and, via a fourth drive motor (not shown), drives a front arm 11 in rotation, which forms a fifth link G5.

[0058] A first leg 12a and a second leg 12b extend forward in a forked manner from the front arm 11. The two legs 12a, 12b support 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 fastening flange 14, 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 case of the exemplary embodiment shown, these joints L1 to L6 connect the links G1 to G7 in the manner of a serial kinematics of a kick-arm robot.

[0059] One or more of the joints L1 to L6 of the robot arm 3 can have an axis limiting device 15 according to the invention. In a specific embodiment, for example, the joint L1, which rotatably connects the base frame 5 as the first link G1 of the robot arm 3 to the carousel 7 as the second link G2 of the robot arm 3, can have the axis limiting device 15. The axis limiting device 15 thus serves to mechanically limit the maximum angle of rotation at a rotary joint L, which directly rotatably connects a first link G1 to a second link G2.

[0060] The axle limiting device 15 as such is in Fig. 2 to Fig. 11 shown.

[0061] The axis limiting device 15 has a movable stop body 16. The stop body 16 is in Fig. 12 in a standalone position. In the present embodiment, the stop body 16 comprises a cuboid base portion 16a and a circular cylindrical head portion 16b.

[0062] The axle limiting device 15 comprises a first guide member F1 which can be connected to the first member G1 or is formed thereon and which has a first groove 17.1 with a first groove track 17a which is designed for the adjustable mounting of the foot section 16a of the stop body 16 along the first groove track 17a and for the limiting mounting of the foot section 16a of the stop body 16 transversely to the first groove track 17a.

[0063] The axis limiting device 15 also comprises a second guide member F2 which can be connected to the second member G2 or is formed thereon and which has a guide surface on which a second groove 17.2 is formed, which has a second groove track 17b which extends circumferentially around an axis of rotation D by more than 360 degrees, as is particularly shown in Fig. 2, Fig. 4 and Fig. 5, wherein the second groove 17.2 is designed for adjustably supporting the head portion 16b of the stop body 16 along the second groove path 17b and for limitingly supporting the head portion 16b of the stop body 16 transversely to the second groove path 17b.

[0064] In the axis limiting device 15, the first guide member F1 and the second guide member F2 are arranged relative to one another in such a way that the stop body 16 simultaneously engages with its foot section 16a in the first groove 17.1 of the first member G1 and with its head section 16b in the second groove 17.2 of the second member G2, so that upon relative rotation of the first guide member F1 against the second guide member F2 about the axis of rotation D, the stop body 16 moves both through the first groove track 17a of the first groove 17.1 and through the second groove track 17b of the second groove 17.2 in a circumferential manner about the axis of rotation D.

[0065] In the illustrated embodiment, the first groove 17.1 has a first groove track 17a which extends at least substantially radially to the axis of rotation D and is designed for the radially adjustable mounting of the foot section 16a of the stop body 16 along the first groove track 17a and for the limiting mounting of the foot section 16a of the stop body 16 in a circumferential direction about the axis of rotation D, wherein the guide surface extends perpendicular to the axis of rotation D, and at least a first groove track section 17b.1 of the second groove 17.2 extends on an inner annular surface section RI of the guide surface and at least a second groove track section 17b.2 of the second groove 17.2 extends on an outer annular surface section RA of the guide surface which is different from the inner annular surface section RI, wherein the second groove 17.2 is designed for adjustable mounting of the head portion 16b of the stop body 16 along the second groove track 17b and for limiting mounting of the head portion 16b of the stop body 16 in the radial direction to the axis of rotation D.

[0066] In the case of the present embodiment, the second guide member F2 is designed as a circular disc, one disc surface of which forms the guide surface in which the second groove 17.2 is introduced. As in Fig. 4 to Fig. 11, in the case of the present embodiment, the second groove track 17b has a spiral course.

[0067] The second groove 17.2 has a first counter stop surface 18.1 for the stop body 16 at one end of the second groove track 17b to limit the angle of rotation in one direction of rotation and a second counter stop surface 18.2 for the stop body 16 at the other end of the second groove track 17b to limit the angle of rotation in the opposite direction of rotation.

[0068] As in Fig. 5, the axle limiting device 15 can have at least one stopper insert 19 which is designed for the detachable and / or adjustable insertion of the stopper insert 19 into the second groove 17.2 at a point on the second groove 17b lying between one end of the second groove track 17b and the other end of the second groove track 17b, wherein the stopper insert 19 forms a third counter stop surface 18.3 for the stop body 16 on its side facing the stop body 16.

[0069] The first groove 17.1 has a first counter surface 20.1 for the stop body 16 at one end of the first groove track 17a to limit the angle of rotation in one direction of rotation and a second counter surface 20.2 for the stop body 16 at the other end of the first groove track 17a to limit the angle of rotation in the opposite direction of rotation.

[0070] As also in Fig. 5, the axle limiting device 15 can have at least one stopper element 21 which is designed for the detachable and / or adjustable insertion of the stopper element 21 into the first groove 17.1 at a point on the first groove 17a lying between one end of the first groove track 17a and the other end of the first groove track 17a, wherein the stopper element 21 forms a third counter surface 20.3 for the stop body 16 on its side facing the stop body 16.

[0071] In Fig. 6 to 11, the axis limiting device 15 is shown from above, in each case in a rotation angle position progressively changed by 180 degrees.

[0072] The current actual position of the stop body 16 is indicated by a solid black dot in the second groove path 17b of the second groove 17.2. An open dot or a ring indicates the previous position of the stop body 16 in the actual position of the stop body 16 shown immediately before in the previous figure, in order to illustrate the progressive movement of the stop body 16 in a straight, radial direction within the first groove 17.1 from the outside right to the inside left during a rotational movement of the first guide member F1 relative to the second guide member F2.

[0073] In Fig. 6, the head portion 16b of the stop body 16 is located at the outer end of the spiral second groove 17.2. In the Fig. 7, the second guide member F2 is rotated 180 degrees counterclockwise relative to the first guide member F1, the stop body 16 has moved radially further to the left within the straight, radially aligned first groove 17.1. This linear movement of the stop body 16 in the first groove 17.1 continues in Fig. 8, Fig. 9 and Fig. 10 with each further rotation by a further 180 degrees counterclockwise, again by the same length of a partial section in the first groove 17.1 radially inwards towards the axis of rotation D. In Fig. 11, the stop body 16 has almost reached the opposite inner end of the second groove 17.2, in which area the total maximum possible angle of rotation of, for example, 900 degrees ends, which accordingly corresponds to 2.5 full revolutions.

[0074] The Fig. Figure 12 shows an exemplary embodiment of a stop body 16 in a standalone position. The stop body 16 is rigid.

[0075] In the case of the present embodiment, the stop body 16 is designed as a pin, one pin half of which forms the head section 16b of the stop body 16 and the other pin half of which forms the foot section 16a.

[0076] In this case, the head portion 16b is formed as a pin portion with a circular cylindrical cross section and the foot portion 16a is formed as a pin portion with a rectangular or square cross section.

[0077] The Fig.Figure 13 shows a modified design of a robot arm 3 in the manner of a lightweight robot 3a with a total of seven axes. This lightweight robot 3a has several links G and joints L that adjust the links G relative to one another, each of which is designed as a pivot joint. Thus, each pivot G connects a first link G1 of the robot arm 3 to an immediately adjacent second link G2 of the robot arm 2 in a manner that allows rotation relative to one another. The corresponding pivot joint G can each have an axis limiting device 15 according to one of the described embodiments.

[0078] The first guide member F1 of the axis limiting device 15 can be designed as a component separate from the first member G1 of the robot arm 3 or the lightweight robot 3a and fastened to the first member G1 of the robot arm 3 and in the same way the second guide member F2 of the axis limiting device 15 can be designed as a component separate from the second member G2 of the robot arm 3 or the lightweight robot 3a and fastened to the second member G2 of the robot arm 3.

[0079] Alternatively, the first guide member F1 of the axis limiting device 15 can be formed together with the first member G1 of the robot arm 3 or the lightweight robot 3a as a one-piece component and in the same way the second guide member F2 of the axis limiting device 15 can be formed together with the second member G2 of the robot arm 3 as a one-piece component. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 301 725 B1

[0002]

Claims

[1] Axis limiting device for mechanically limiting the maximum angle of rotation at a rotary joint which directly connects a first member (G1) to a second member (G2) in a rotatable manner, comprising: - a movable stop body (16) with a foot section (16a) and a head section (16b), - a first guide member (F1) connectable to the first member (G1) or formed thereon, which has a first groove (17.1) with a first groove track (17a) which is designed for adjustably supporting the foot section (16a) of the stop body (16) along the first groove track (17a) and for limitingly supporting the foot section (16a) of the stop body (16) transversely to the first groove track (17a), - a second guide member (F2) which can be connected to the second member (G2) or is formed thereon and which has a guide surface on which a second groove (17.2) is formed, which has a second groove track (17b) which extends circumferentially around an axis of rotation (D) by more than 360 degrees, wherein the second groove (17.2) is designed for the adjustable mounting of the head section (16b) of the stop body (16) along the second groove track (17b) and for the limiting mounting of the head section (16b) of the stop body (16) transversely to the second groove track (17b), wherein - the first guide member (F1) and the second guide member (F2) are arranged relative to one another in such a way that the stop body (16) simultaneously engages, on the one hand, with its foot section (16a) in the first groove (17.1) of the first member (G1) and, on the other hand, with its head section (16b) in the second groove (17.2) of the second member (G2), so that upon relative rotation of the first guide member (F1) against the second guide member (F2) about the axis of rotation (D), the stop body (16) moves both through the first groove track (17a) of the first groove (17.1) and through the second groove track (17b) of the second groove (17.2) in a circumferential manner about the axis of rotation (D). [2] Axle limiting device according to claim 1, characterized bythat the first groove (17.1) has a first groove track (17a) extending at least substantially radially to the axis of rotation (D), which is designed for the radially adjustable mounting of the foot section (16a) of the stop body (16) along the first groove track (17a) and for the limiting mounting of the foot section (16a) of the stop body (16) in a circumferential direction around the axis of rotation (D), and the guide surface extends perpendicular to the axis of rotation (D), and at least a first groove track section (17b.1) of the second groove (17.2) extends on an inner annular surface section (RI) of the guide surface and at least a second groove track section (17b.2) of the second groove (17.2) extends on an outer annular surface section (RA) of the guide surface which is different from the inner annular surface section (RI), wherein the second groove (17.2) is designed for adjustably supporting the head portion (16b) of the stop body (16) along the second groove track (17b) and for limitingly supporting the head portion (16b) of the stop body (16) in the radial direction to the axis of rotation (D). [3] Axle limiting device according to claim 2, characterized by that the second guide member (F2) is designed as a circular disc, one disc surface of which forms the guide surface in which the second groove (17.2) is introduced. [4] Axle limiting device according to claim 2 or 3, characterized by that the second groove track (17b) has a spiral course. [5] Axle limiting device according to claim 1, characterized bythat the first groove (17.1) has a first groove track (17a) extending at least substantially parallel to the axis of rotation (D), which is designed for the adjustably supporting of the foot section (16a) of the stop body (16) along the first groove track (17a) parallel to the axis of rotation (D) and for the limiting supporting of the foot section (16a) of the stop body (16) in a circumferential direction around the axis of rotation (D), and the guide surface is an inner cylinder jacket wall running concentrically to the axis of rotation (D), and at least a first groove track section of the second groove (17.2) extends on an upper cylinder surface section of the inner cylinder jacket wall and at least a second groove track section of the second groove (17.2) extends on a lower cylinder surface section of the guide surface that is different from the upper cylinder surface section, wherein the second groove (17.2) is designed for adjustably supporting the head portion (16b) of the stop body (16) along the second groove track (17b) and for limitingly supporting the head portion (16b) of the stop body (16) in a direction parallel to the axis of rotation (D). [6] Axle limiting device according to claim 5, characterized by that the second guide member (F2) is designed as a hollow circular cylindrical pipe section, the inner cylinder wall of which forms the guide surface in which the second groove (17.2) is introduced. [7] Axle limiting device according to claim 5 or 6, characterized by that the second groove track (17b) has a helical course. [8] Axle limiting device according to one of claims 1 to 7, characterized bythat the second groove (17.2) has a first counter-stop surface (18.1) for the stop body (16) at one end of the second groove track (17b) to limit the angle of rotation in one direction of rotation and a second counter-stop surface (18.2) for the stop body (16) at the other end of the second groove track (17b) to limit the angle of rotation in the opposite direction of rotation. [9] Axle limiting device according to claim 8, characterized by that the first counter-stop surface (18.1) of the second groove (17.2) has a first spring device which is designed to cushion the striking of the stop body (16) against the first counter-stop surface (18.1), and / or the second counter-stop surface (18.2) of the second groove (17.2) has a second spring device which is designed to cushion the striking of the stop body (16) against the second counter-stop surface (18.2). [10] Axle limiting device according to one of claims 1 to 9, characterized by at least one stopper insert part (19) which is designed for the detachable and / or adjustable insertion of the stopper insert part (19) into the second groove (17.2) at a point of the second groove track (17b) lying between one end of the second groove track (17b) and the other end of the second groove track (17b), wherein the stopper insert part (19) forms a third counter-stop surface (18.3) for the stop body (16) on its side facing the stop body (16). [11] Axle limiting device according to claim 10, characterized by that the third counter-stop surface (18.3) of the stopper insert part (19) has a third spring device which is designed to cushion an impact of the stop body (16) on the third counter-stop surface (18.3). [12] Axle limiting device according to one of claims 1 to 11, characterized bythat the second groove (17.2) is assigned a second position measuring system which is designed and configured to detect the position of the stop body (16) at its current location on the second groove path (17b). [13] Axle limiting device according to one of claims 1 to 12, characterized by that the first groove (17.1) has a first counter-surface (20.1) for the stop body (16) at one end of the first groove track (17a) to limit the angle of rotation in one direction of rotation and a second counter-surface (20.2) for the stop body (16) at the other end of the first groove track (17a) to limit the angle of rotation in the opposite direction of rotation. [14] Axle limiting device according to claim 13, characterized bythat the first counter surface (20.1) of the first groove (17.1) has a first spring device which is designed to cushion an impact of the stop body (16) on the first counter surface (20.1), and / or the second counter surface (20.2) of the first groove (17.1) has a second spring device which is designed to cushion an impact of the stop body (16) on the second counter surface (20.2). [15] Axle limiting device according to one of claims 1 to 14, characterized by at least one stopper element (21) which is designed for the detachable and / or adjustable insertion of the stopper element (21) into the first groove (17.1) at a point of the first groove track (17a) lying between one end of the first groove track (17a) and the other end of the first groove track (17a), wherein the stopper element (21) forms a third counter-surface (20.3) for the stop body (16) on its side facing the stop body (16). [16] Axle limiting device according to claim 15, characterized by that the third counter surface (20.3) of the stopper element (21) has a third spring device which is designed to cushion an impact of the stop body (16) on the third counter surface (20.3). [17] Axle limiting device according to one of claims 1 to 16, characterized by that the first groove (17.1) is assigned a first position measuring system which is designed and configured to detect the position of the stop body (16) at its current location on the first groove path (17a). [18] Axle limiting device according to one of claims 1 to 17, characterized by that the stop body (16) is rigid. [19] Axle limiting device according to one of claims 1 to 18, characterized bythat the head section (16b) of the stop body (16) and / or the foot section (16a) of the stop body (16) is provided with a spring-elastic jacket on its respective outer jacket wall. [20] Axle limiting device according to one of claims 1 to 19, characterized by that the stop body (16) is designed as a pin, one pin half of which forms the head section (16b) of the stop body (16) and the other pin half of which forms the foot section (16a). [21] Axle limiting device according to claim 20, characterized by that the head section (16b) is designed as a pin section with a circular cylindrical cross section and the foot section (16a) is designed as a pin section with a rectangular or square cross section. [22] Robot arm with several links (G1-G7) and joints (L1-L6) which adjust the links (G1-G7) relative to one another, of which at least one joint (L1-L6) is designed as a rotary joint which connects a first link (G1) of the robot arm (3) to an immediately adjacent second link (G2) of the robot arm (3) in a manner which can rotate relative to one another, wherein the rotary joint has an axis limiting device (15) according to one of claims 1 to 21. [23] Robot arm according to claim 22, characterized by that the first guide member (F1) of the axis limiting device (15) is designed as a component separate from the first member (G1) of the robot arm (3) and is fastened to the first member (G1) of the robot arm (3) and / or the second guide member (F2) of the axis limiting device (15) is designed as a component separate from the second member (G2) of the robot arm (3) and is fastened to the second member (G2) of the robot arm (3). [24] Robot arm according to claim 22, characterized bythat the first guide member (F1) of the axis limiting device (15) is designed as a one-piece component together with the first member (G1) of the robot arm (3) and / or the second guide member (F2) of the axis limiting device (15) is designed as a one-piece component together with the second member (G2) of the robot arm (3).

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