Seal for a radial gap between two elements of a robot arm

Abstract

The invention relates to a robot arm having at least two elements (11, 12), which are rotatably connected together relative to each other about a rotational axis (D) in a joint (13), and a seal assembly having a seal support (20), which is secured to one of the two elements, and an elastic seal (30), which is supported on the seal support and on the other element in order to seal a radial gap (S) between the two elements.

Description

[0001] Description

[0002] Sealing a radial gap between two links of a robot arm

[0003] The present invention relates to the sealing of a radial gap between two links of a robot arm.

[0004] Robot arms often have several joints in which two links of the robot arm are connected to each other in such a way that they can be rotated relative to each other around a rotation axis of the respective joint.

[0005] Radial shaft seals according to DIN 3760 are commonly used to seal radial gaps between components that can rotate relative to each other. However, these have fixed outer and inner diameters and widths, so the components to be sealed must be adapted accordingly depending on the dimensions of the preselected radial shaft seal. This can, in particular, lead to housing components and / or shafts having to be made unnecessarily large and / or heavy in order to install the corresponding radial shaft seal.

[0006] The object of the present invention is to improve the sealing of a radial gap between two links of a robot arm, preferably to reduce the aforementioned disadvantages, in particular to avoid them.

[0007] This object is achieved by a robot arm having the features of claim 1. Claims 14-16 protect a corresponding sealing arrangement or one described here, or the use thereof, or a method for sealing at least one radial gap of a robot arm in the manner described here, in particular using a corresponding sealing arrangement or one described here. The subclaims relate to advantageous developments, wherein the features of the subclaims which refer back to claim 1 can each also form features of advantageous developments of the subject matter of claims 14-16. According to one embodiment of the present invention, a robot arm has one or more pairs of links, each having two links, which are each connected to one another in a joint (of the respective pair of links) in such a way that they can rotate relative to one another about an axis of rotation (of the respective pair of links orJoint) are rotatable, wherein in one embodiment, the two links of the or one or more of the link pairs (each) are rotatable about the respective axis of rotation by a drive, preferably an electric motor. In this case, one link of a link pair can simultaneously be a link of another of the link pairs of the robot arm. In one embodiment, the robot arm has at least three, in particular exactly or at least six, in one embodiment exactly or at least seven, joints.

[0008] According to one embodiment of the present invention, in order to seal a radial gap between one member of the or one or more of the pairs of members, which in the present case is also referred to (in each case) as the first member (of the (respective) pair of members without restriction of generality, and the other member of this (respective) pair of members, which in the present case is referred to (in each case) as the second member (of this (respective) pair of members without restriction of generality), a sealing arrangement is (in each case) provided or used, which (in each case) has (in each case) a seal carrier which is fastened to the (respective) one or first of the two members, and an elastic seal which, in order to seal the (respective) radial gap between the (respective) one or first and the (respective) other or second of the (respective) two members, on the one hand on this seal carrier and on the other hand on the (respective) other or secondsecond member, preferably (at least) in the radial direction, in particular is or will be clamped or compressed between them (at least in the radial direction).

[0009] By providing or using a separate seal carrier in one embodiment (each), the two links can advantageously be dimensioned more freely. Additionally or alternatively, this makes it possible to reduce material and therefore weight, particularly on the side of the (respective) one or first link. Additionally or alternatively, this makes it possible to adapt the seal carrier and / or the seal more easily in one embodiment without having to modify one or the first and / or the other or second link. Additionally or alternatively, this makes it possible to assemble, disassemble, maintain and / or inspect the seal carrier and / or the seal more easily in one embodiment.

[0010] In particular, one or first link of the or one or more of the link pairs can (in each case) be a more proximal or base-side link of the robot arm, and the other or second link of this or these link pairs can (in each case) be a more distal or end-effector-side link of the robot arm. This can be particularly advantageous because it means that more distal links do not have to bear the weight of the sealing arrangement explained below. Likewise, one or first link of the or one or more of the link pairs can (in each case) be a more distal or end-effector-side link of the robot arm, and the other or second link of this or these link pairs can (in each case) be a more proximal or base-side link of the robot arm. The present invention can also be particularly advantageous in this case, in particular because, as explained below, the weight of the first link can be reduced.

[0011] In one embodiment, the seal carrier and / or the elastic seal is ring-shaped.

[0012] This can improve the sealing effect and / or installation in one design.

[0013] In one embodiment, the seal carrier and / or the elastic seal (each) is formed in one piece.

[0014] This allows weight to be (further) reduced in one version.

[0015] In one embodiment, the seal carrier and / or the elastic seal (each) is constructed in several parts.

[0016] This can (further) improve assembly and / or function in one embodiment. In particular, the seal carrier can be designed as a single piece and the elastic seal as a multi-piece, or conversely, the seal carrier can be designed as a multi-piece and the elastic seal as a single piece.

[0017] In one embodiment, the or one or more of the seal carriers are or are fastened (each) frictionally to the (respective) one or first member, in one embodiment in such a way that there is an interference fit between the seal carrier and the one or first member, and / or by pressing in or on, preferably in the axial direction, and / or shrinking.

[0018] In this embodiment, “axial” refers to the (respective) axis of rotation, “radial” accordingly refers to a direction perpendicular to the (respective) axis of rotation and the rotation or circumferential direction around it, preferably outwards away from the (respective) axis of rotation.

[0019] In this way, an advantageous, preferably low-vibration fastening can be realized in one embodiment.

[0020] Additionally or alternatively, this or one or more of these seal carriers and / or one or more further seal carriers is or will be fastened (in each case) in a form-fitting manner to the (respective) one or first member, in one embodiment secured, preferably fixed or secured, in the axial, radial and / or circumferential direction.

[0021] In this way, an advantageous, preferably more robust, fastening can be realized in one embodiment.

[0022] In addition or alternatively to a positive and / or frictional fastening, one or more of the seal carriers are or will be fastened (each) materially to the (respective) one or first member, in one embodiment by bonding and / or welding.

[0023] This allows for an advantageous, preferably more reliable, fastening in one embodiment. Particularly preferred is the combination of bonding with pressing and / or shrinking, which, as mentioned above, allows for a particularly reliable and, at the same time, low-vibration fastening.

[0024] In one embodiment, the or one or more of the seal carriers are or are fastened (each) in a radial, preferably end-side arranged, recess of a wall of the (respective) one or first member, preferably thin-walled in this area, preferably in a recess open towards an end side of this wall and / or ring-like.

[0025] This allows the seal carrier to be positioned more reliably, more compactly, more simply and / or more protected.

[0026] In one embodiment, the or one or more of the seal carriers are or are arranged (each) on an inner side of the (respective) one or first member.

[0027] This allows the seal carrier to be positioned more reliably, more compactly and / or more protected in one design.

[0028] In one embodiment, the one or more of the seal carriers are or are arranged (each) on an outer side of the (respective) one or first member.

[0029] In one embodiment, this allows the seal carrier to be positioned more easily and / or the member to be dimensioned advantageously.

[0030] In one embodiment, the or one or more of the elastic seals are or are arranged (each) on an inner side of the (respective) other or second member.

[0031] In one embodiment, this allows the seal to be positioned more reliably, more compactly, and / or more securely. In one embodiment, the elastic seals are arranged on an outer side of the other or second member.

[0032] This makes it easier to position and / or maintain the seal in one version.

[0033] In one embodiment, the or one or more of the elastic seals (each) are supported in a radial, preferably end-side arranged, recess of a wall of the (respective) other or second member, preferably thin-walled in this area, preferably in a ring-like recess open towards an end side of this wall.

[0034] This makes it easier to install and / or maintain the seal in one version.

[0035] In one embodiment, the seal carrier(s) or one or more of the seal carriers (each) have a radial recess, in a further development a radial groove, in which the (respective) seal is supported, in one embodiment being axially secured on one or both sides.

[0036] In one embodiment, this allows the seal to be positioned more reliably and / or more compactly and / or more protected.

[0037] In one embodiment, the one or more of the one or first members are (each) a single-part or multi-part metal and / or cast component.

[0038] This is particularly advantageous for robot arm limbs, particularly due to their shape and stability requirements. The invention can be used particularly advantageously for (metal) castings, since the seal carrier(s) can significantly save material and thus weight, or allow for more advantageous dimensions for the casting. Additionally or alternatively, one or more of the seal carriers are (each) a single- or multi-part metal component in one embodiment. This allows the associated seal to be supported more reliably in one embodiment.

[0039] Additionally or alternatively, in one embodiment, the one or more of the first members and the (respective) seal carrier attached thereto are (respectively) made of different materials. In one embodiment, the one or more of the first members and the (respective) seal carrier attached thereto are (respectively) made of the same material.

[0040] By using links and seal carriers made of different materials, weight can be (further) reduced in one design, and by using links and seal carriers made of the same material in one design, their connection can be improved.

[0041] Additionally or alternatively, the seal carrier(s) and the seal supported thereon (respective) are made of different materials in one embodiment and / or the seal(s) are a single-part or multi-part plastic component.

[0042] This can improve the sealing effect in one design.

[0043] In one embodiment, the or one or more of the one or first members and / or the or one or more of the seal carriers comprises aluminum, in particular at least one aluminum alloy.

[0044] This allows weight to be (further) reduced in one version.

[0045] In one embodiment, the or one or more of the sealing arrangements are (respectively) designed such that sealing between the two members by the (respective) seal meets at least protection class IP5 and / or IP54, in particular according to ISO 20653 and / or DIN EN 60529.

[0046] As a result, in one embodiment, the robot arm can be designed or used particularly advantageously. As mentioned above, the present invention also relates to the use of one or more sealing assemblies, as described here, for sealing radial gaps between two members of a robot arm that are connected to one another in a joint such that they can rotate relative to one another about an axis of rotation, a sealing assembly with a seal carrier and an elastic seal for sealing the radial gap between two members of a robot arm that are connected to one another in a joint such that they can rotate relative to one another about an axis of rotation, as described here, and a method for sealing a radial gap between one or the first and the other or the second of (respectively) two members of one or more pairs of members of a robot arm as described here.The advantages mentioned here apply equally to the use, sealing arrangement and process.

[0047] In one embodiment, the seal carrier(s) or one or more of the seal carriers are (respectively) fastened to the (respective) one or first member, and during or preferably by this fastening, the (respective) elastic seal is tensioned, preferably tensioned or compressed (at least) in the radial direction, to seal the radial gap between the seal carrier and the other or second member. This can simplify the assembly of the seal in one embodiment.

[0048] In one embodiment, the seal carrier(s) or one or more of the seal carriers are (respectively) attached to the (respective) one or first member, and then, or with the seal carrier already attached, the (respective) elastic seal for sealing the radial gap between the seal carrier and the other or second member is preferably tensioned (at least) in the radial direction, in particular compressed, in one embodiment by mounting the (respective) other or second member on the one or first member. This allows the members to be simplified in one embodiment.

[0049] Further advantages and features emerge from the subclaims and the exemplary embodiments. The following shows, partly schematically:

[0050] Fig. 1: a robot arm according to an embodiment of the present invention; and Fig. 2: a detail of a joint of the robot arm in an axial section.

[0051] Fig. 1 shows an example of a six-axis robot arm, which is preferably intended for, configured for, or used for collaboration with humans, and / or, in one embodiment, is arranged on a mobile platform. The present invention is particularly advantageous for this purpose due to the usual constraints, but is not limited thereto.

[0052] Fig. 2 shows an enlarged section through a detail of the base frame 11 and the carousel 12, which are connected to one another in a proximal pivot joint 13 so as to be rotatable about a vertical axis of rotation D. The present invention will now be explained using this example as an example, as this joint represents a particularly preferred application. Additionally or alternatively, the present invention can also be advantageously used with other joints, for example the subsequent joint with a horizontal axis of rotation. As explained above, the designation of one link (in the example of the base frame 11) as the “first link” and the other link (in the example of the carousel 12) as the “second link” is used without restriction of generality, although it can be particularly advantageous if the more proximal link is the one or first link.

[0053] Fig. 2 shows a (part of a) ring-like seal carrier(s) 20, which has an axial flange 20A, which is pressed into a front-side radial recess 11B in a wall 11A of the base frame 11 and additionally glued therein and is thereby arranged on an inner side of the base frame 11.

[0054] An annular elastic seal 30 is supported radially on one side in a radial annular groove 20B of the seal carrier 20 and on the other side in a radial recess 12B in a wall 12A of the carousel 12, and is compressed radially between them. Due to the support in the annular groove 20B, it is axially secured on both sides (top and bottom in Fig. 2).

[0055] This advantageously seals a radial gap S between base frame 11 and carousel 12. Although exemplary embodiments have been explained in the preceding description, it should be noted that a multitude of modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples that are not intended to limit the scope of protection, applications, or design in any way. Rather, the preceding description provides the person skilled in the art with a guide for implementing at least one exemplary embodiment, wherein various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as it results from the claims and combinations of features equivalent to these.

[0056] List of reference symbols

[0057] 10 Robot arm

[0058] 11 Base frame 11A Wall

[0059] 11 B radial recess

[0060] 12 Carousel

[0061] 12A wall

[0062] 12B radial recess 13 joint

[0063] 20 seal carriers

[0064] 20A flange

[0065] 20B radial groove

[0066] 30 elastic seal D rotation axis

[0067] S radial gap

Claims

Patent claims 1. Robot arm with at least two links (11 , 12) which are connected to each other in a joint (13) so as to be rotatable about an axis of rotation (D), and a sealing arrangement comprising a sealing carrier (20) which is attached to one of the two links, and an elastic seal (30) which is supported on the one hand on the sealing carrier and on the other hand on the other link to seal a radial gap (S) between this one and the other of the two links.

2. Robot arm according to claim 1, characterized in that the sealing carrier is attached to one member by friction, form and / or material locking.

3. Robot arm according to one of the preceding claims, characterized in that the sealing carrier is fixed in a radial recess (11 B) of a wall (11 A) of one member and / or an interference fit exists between the sealing carrier and the one member.

4. Robot arm according to one of the preceding claims, characterized in that the sealing carrier is arranged on an inner side of one link.

5. Robot arm according to one of the preceding claims 1-3, characterized in that the sealing carrier is arranged on an outer side of one member.

6. Robot arm according to one of the preceding claims, characterized in that the seal is arranged on an inner side of the other link.

7. Robot arm according to one of the preceding claims 1-5, characterized in that the seal is arranged on an outer side of the other member.

8. Robot arm according to one of the preceding claims, characterized in that the seal is supported in a radial recess (12B) of a wall (12A) of the other member.

9. Robot arm according to one of the preceding claims, characterized in that the sealing carrier has a radial recess, in particular a groove (20B), in which the seal is supported, in particular axially secured.

10. Robot arm according to one of the preceding claims, characterized in that one member is a one- or multi-part metal and / or cast component and / or the sealing carrier is a one- or multi-part metal component and / or the seal is a one- or multi-part plastic component and / or the sealing carrier and the seal are made of different materials.

11. Robot arm according to one of the preceding claims, characterized in that the sealing carrier and one link are made of different materials.

12. Robot arm according to one of the preceding claims 1-10, characterized in that the sealing carrier and the one link are made of the same material.

13. Robot arm according to one of the preceding claims, characterized in that the sealing between the two elements by means of the seal meets at least the protection class IP5 and / or IP54.

14. Use of a sealing arrangement with a sealing carrier (20) and an elastic seal (30) for sealing the radial gap (S) between the two links (11, 12) of a robot arm (10) which are rotatably connected to each other in the joint (13) about the axis of rotation (D) according to one of the preceding claims. A sealing arrangement comprising a sealing carrier (20) and an elastic seal (30) for sealing the radial gap (S) between the two links (11, 12) of a robot arm (10) which are rotatably connected to each other about the axis of rotation (D) in a joint (13) according to one of the preceding claims. A method for sealing a radial gap (S) between one and the other of two links (11, 12) of at least one pair of links of a robot arm (10), in particular according to one of the preceding claims 1 to 13, which are rotatably connected to each other about an axis of rotation (D) in a joint (13), wherein a sealing carrier (20), in particular a sealing arrangement according to claim 15, is attached to one link, and an elastic seal (30), in particular the seal of the sealing arrangement according to claim 15, is clamped to seal the radial gap between the sealing carrier and the other link.

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