METHOD FOR ATTACHING A ROLLER HEAD TO A WELDING ARM FOR A RESISTANCE SEAM WELDING MACHINE

Description

Technical field

[0001] The invention relates to a method for attaching a roller head to a welding arm for a resistance seam welding machine, an arrangement comprising a welding arm for a resistance seam welding machine and a roller head attached thereto, a resistance seam welding machine with such an arrangement, a roller head for such an arrangement, and the use of the arrangement for resistance seam welding of the longitudinal seam of can frames according to the preambles of the independent claims. State of the art

[0002] Liquid-cooled roller heads for welding arms for resistance welding machines are known from documents DE 40 20 182 C1 and WO 2013 / 181765 A1. Resistance welding machines with a welding arm with a roller head attached to it are known from documents DE 34 32 499 A1 (basis for the preamble of claims 1 and 11), DE 27 47 222 A1 and EP 0 714 723 A1, and document CH 688 689 A5 relates to a Z-rail for such a resistance welding machine.

[0003] The roller heads comprise a stator and an electrode roller, which is mounted on the stator as a rotor, allowing it to rotate around an axis of rotation. The stator extends beyond the electrode roller on both sides of the rotation axis, with mounting extensions. Under normal use, the electrode rollers of the roller heads wear around their circumference and are reworked a few times to extend their service life until the wear limit is reached. This reworking is done with the roller heads removed from the vehicle. Consequently, the roller heads must be replaced relatively frequently. The mounting extensions, which are designed as circular cylindrical shaft stubs, serve to attach the roller head to the welding arm, to transmit the welding current from the welding arm to the roller head, and to supply and remove coolant for cooling the roller head.For the latter purpose, the mounting extensions have radial inlet and outlet bores, which must be aligned with corresponding inlet and outlet bores in the welding arm during assembly. Aside from the fact that assembly errors can occur when aligning the inlet and outlet bores, the roller heads currently known also frequently suffer from leaks in the area of ​​the inlet and outlet bores, as well as contact problems, which can lead to costly machine downtime for troubleshooting. Description of the invention

[0004] The task, therefore, is to provide a technical solution that can avoid the disadvantages of the state of the art in a cost-effective manner, either completely or at least partially.

[0005] This problem is solved by the subject matter of the independent patent claims.

[0006] According to these, a first aspect of the invention relates to a method for attaching a roller head to a welding arm for a resistance seam welding machine. The roller head comprises a stator and an electrode roller, which is mounted as a rotor on the stator so as to be rotatable about an axis of rotation. The stator projects beyond the electrode roller on both sides in the direction of the axis of rotation with fastening extensions.

[0007] The process includes the following steps: a) Providing a welding arm for a resistance welding machine, which in its intended operating state has a receiving opening for the roller head formed between two opposing, preferably parallel, boundary walls, which in turn have mounting receiving openings for the mounting extensions of the roller head's stator; b) Arranging the roller head in the receiving opening for the roller head such that the electrode roller protrudes from the receiving opening with a portion of its circumferential boundary and the mounting extensions are arranged in the mounting receiving openings; and c) Attaching the roller head to the welding arm by pressing the mounting extensions of the stator, each with a flat contact surface formed thereon, against an associated flat contact surface within the boundaries of the respective mounting receiving opening. wherein the contact surfaces of the stator mounting extensions and the associated contact surfaces have inlet and outlet openings for a cooling medium and the stator mounting extensions are arranged and fastened in the mounting openings for the mounting extensions in such a way that the inlet and outlet openings each overlap at least partially, and wherein the stator mounting extensions are each pressed with their contact surfaces against the associated contact surfaces by means of a clamping piece received in the respective mounting opening.

[0008] It has been shown that the invention can prevent assembly errors and achieve good and reliable sealing and power transmission.

[0009] In a first embodiment, the associated contact surface is provided by an adapter assembly located in the respective mounting opening, which in turn is pressed against an associated contact surface formed by the boundaries of the respective mounting opening. Such solutions are primarily suitable as retrofit solutions for existing welding arms according to the prior art.

[0010] In a second preferred embodiment, the associated contact surface is provided by the boundaries of the respective mounting opening, and not, as in the first embodiment, by an additional component arranged between these boundaries and the contact surface of the respective mounting extension. This enables direct current transfer from the welding arm to the mounting extensions of the roller head, and the mounting openings can be made smaller, resulting in a more robust welding arm design. It also becomes possible to attach the roller head to the welding arm with very few, easily manufactured parts, which facilitates cost-effective solutions and requires little expertise and time for roller head replacement.

[0011] Preferably, the contact surfaces on the stator's mounting projections and the corresponding contact surfaces of the mounting opening boundaries on the welding arm run in planes parallel to the axis of rotation of the electrode roller, advantageously perpendicular to the longitudinal axis of the welding arm. In this way, large, position-tolerant contact surfaces can be formed between the stator's mounting projections and the mounting opening boundaries on the welding arm, and the roller head's stator, when mounted, has a precisely defined rotational position relative to the contact surfaces of the mounting opening boundaries on the welding arm.

[0012] The clamping elements are advantageously guided by the boundaries of the mounting openings to allow for displacement in the clamping direction. This is preferably achieved by the clamping elements having flat guide surfaces, extending in the contact direction, that abut corresponding guide surfaces of the boundaries of the mounting openings.

[0013] In this way, the mounting extensions of the stator can be reliably and in a controlled manner pressed against the contact surfaces of the boundaries of the mounting openings of the welding arm.

[0014] It is preferred that the mounting extensions of the stator and the mounting openings on the welding arm are designed such that the mounting extensions, with their contact surfaces, can be pressed against the contact surfaces of the mounting opening boundaries in various positions, preferably in various positions transverse to the axis of rotation of the electrode roll and perpendicular to the longitudinal axis of the welding arm. This makes it possible to shift the axis of rotation of the electrode roll transversely to the longitudinal axis of the welding arm and, even with different electrode roll diameters and a stationary welding arm, to ensure that the electrode roll, with its circumferential boundary, always protrudes from the mounting opening by a certain amount and can thus be aligned with the so-called "Z-rail" or the welding plane.

[0015] Advantageously, the positions of the mounting projections are determined by the clamping pieces. When the mounting projections are pressed into place, this creates both a positive fit with the boundaries of the respective mounting opening in a direction parallel to the plane of the contact surfaces and perpendicular to the axis of rotation of the electrode roll, and a positive fit with the respective mounting projection in this same direction. In this way, the positions for specific electrode roll diameters with their corresponding clamping pieces can be reliably and securely determined without complex adjustments.

[0016] The clamping pieces are preferably pressed against the stator's mounting projections by means of clamping screws fixed in the welding arm, thus pressing the mounting projections and their contact surfaces against the corresponding contact surfaces. In this way, all forces used for pressing remain within the welding arm, and large clamping forces can be applied easily and precisely.

[0017] In yet another preferred embodiment of the inventive method, one of the two opposing boundary walls of the receiving opening for the roller head, which form the mounting receiving openings for the mounting extensions of the stator of the roller head, is formed by a component which, preferably pointing away from the axis of rotation of the electrode roller, can be temporarily removed from a main body of the welding arm, which main body forms the other of the two opposing boundary walls of the receiving opening for the roller head.This component is temporarily removed to arrange the roller head in the receiving opening, so that the receiving opening is temporarily open on one side, and after the roller head has been inserted into the main body, it is reinstalled such that one of the mounting extensions of the roller head stator is arranged in the mounting receiving opening formed by the side wall of the main body, and the other mounting extension of the stator is arranged in the mounting receiving opening formed by the side wall of this component.

[0018] This makes it possible to change the roller head in a simple, self-explanatory way and in a short time.

[0019] A second aspect of the invention relates to an arrangement comprising a welding arm for a resistance seam welding machine and a roller head attached thereto. The roller head has a stator and an electrode roller, which is mounted as a rotor on the stator so as to be rotatable about an axis of rotation. The stator projects beyond the electrode roller on both sides in the direction of the axis of rotation by means of mounting extensions.

[0020] The welding arm has a receiving opening for the roller head, which is formed between two opposing, preferably parallel, boundary walls. These boundary walls in turn have mounting openings for the mounting extensions of the roller head's stator.

[0021] The roller head is positioned in the receiving opening such that the electrode roller protrudes from the receiving opening with part of its circumferential boundary, and the mounting projections are arranged in the mounting receiving openings. It is attached to the welding arm by pressing the mounting projections of the stator against a corresponding flat contact surface within the boundaries of the respective mounting receiving opening, with each projection forming a flat contact surface.

[0022] The contact surfaces of the stator's mounting extensions and the associated contact surfaces have inlet and outlet openings for a cooling medium, and the stator's mounting extensions are arranged and fastened in the mounting openings in such a way that the inlet and outlet openings overlap at least partially.

[0023] The mounting extensions of the stator are each pressed against the corresponding contact surfaces by means of a clamping piece inserted in the respective mounting opening.

[0024] It has been shown that the inventive design can prevent assembly errors and achieve good and reliable sealing and power transmission.

[0025] In a first embodiment, the corresponding contact surface is provided by an adapter assembly located in the respective mounting opening, which in turn is pressed against a corresponding contact surface formed by the boundaries of the respective mounting opening. Such solutions are primarily suitable as retrofit solutions for existing welding arms.

[0026] In a second preferred embodiment, the associated contact surface is provided by the boundaries of the respective mounting opening, and not, as in the first embodiment, by an additional component arranged between these boundaries and the contact surface of the respective mounting extension. This enables direct current transfer from the welding arm to the mounting extensions of the roller head, and the mounting openings can be made smaller, allowing for a more robust welding arm design. It also becomes possible to attach the roller head to the welding arm with very few, easily manufactured parts, which facilitates cost-effective solutions and requires minimal expertise and time for roller head replacement.

[0027] The contact surfaces on the stator's mounting projections and the corresponding contact surfaces of the mounting hole boundaries advantageously lie in planes parallel to the axis of rotation of the electrode roller, preferably perpendicular to a longitudinal axis of the welding arm. In this way, large, position-tolerant contact surfaces can be formed between the stator's mounting projections and the mounting hole boundaries on the welding arm, and the roller head's stator has a precisely defined rotational position relative to the contact surfaces of the mounting hole boundaries on the welding arm.

[0028] The mounting holes on the welding arm are advantageously closed all around. This prevents unnecessary structural weakening of the welding arm.

[0029] The clamping pieces are advantageously guided by the limits of the mounting openings to allow for movement in the clamping direction.

[0030] This is preferably achieved by the clamping pieces having flat guide surfaces extending in the pressure direction adjacent to associated guide surfaces of the boundaries of the mounting openings for guidance in order to allow displacement in the clamping direction.

[0031] It is also preferred that the clamping pieces grip the mounting extensions of the stator from the side opposite the contact surface.

[0032] The measures mentioned above make it possible to reliably and in a controlled manner press the mounting extensions of the stator against the contact surfaces of the limits of the mounting openings of the welding arm.

[0033] It is preferred that the mounting extensions of the stator and the mounting openings on the welding arm are designed such that the mounting extensions, with their contact surfaces, can be pressed against the contact surfaces of the mounting opening boundaries in various positions, preferably in various positions transverse to the axis of rotation of the electrode roll and perpendicular to the longitudinal axis of the welding arm. This makes it possible to shift the axis of rotation of the electrode roll transversely to the longitudinal axis of the welding arm and, even with different electrode roll diameters and a stationary welding arm, to ensure that the electrode roll, with its circumferential boundary, always protrudes from the mounting opening by a certain amount and can thus be aligned with the "Z-rail" or the welding plane.

[0034] Advantageously, the positions are fixed using the clamping pieces, as these create a positive fit with the boundaries of the respective mounting opening when the fastening extensions are pressed in, in a direction parallel to the plane of the contact surfaces and perpendicular to the axis of rotation of the electrode roll, and also a positive fit with the respective fastening extension in this direction. In this way, the positions for specific electrode roll diameters with their corresponding clamping pieces can be fixed securely and without complex adjustments.

[0035] In embodiments of the arrangement in which the clamping pieces grip the mounting extensions of the stator from the side opposite the contact surface, it is preferred that the axis of rotation of the electrode roller has different distances to the planes in which the flat guide surfaces of the clamping pieces run in the direction of pressure.

[0036] If the clamping pieces are designed in such a way that they can be installed in two different positions, for the selective positioning of the contact surfaces of the mounting extensions of the stator in two different positions on the contact surfaces of the boundaries of the mounting openings, which is preferred, then it becomes possible to assign the clamping piece to two different electrode roller diameters and thus halve the number of clamping piece dimensions required for a certain number of different electrode roller diameters.

[0037] In a further preferred embodiment of the arrangement according to the invention, the mounting extensions of the stator, viewed in the direction of the axis of rotation of the electrode roller, each have a circular cross-section with a flattened area that forms the contact surface. Such contours are simple and inexpensive to manufacture and enable a precisely defined rotational alignment of the stator of the roller arrangement relative to the welding arm.

[0038] The clamping elements are preferably pressed against the mounting projections of the stator by means of clamping screws fixed in the welding arm, pressing the mounting projections and their contact surfaces against the corresponding contact surfaces of the boundaries of the mounting openings. In this way, all forces required for pressing remain within the welding arm, and large clamping forces can be applied easily and precisely.

[0039] It is preferred that seals are arranged in the contact surfaces of the mounting openings to seal the at least partially overlapping inlet and outlet openings to the outside. This design avoids weakening the mounting extensions of the roller head stator caused by recesses for the seals.

[0040] In yet another preferred embodiment of the arrangement according to the invention, one of the two opposing boundary walls of the receiving opening for the roller head, which provides the mounting openings for the mounting extensions of the roller head's stator, is formed by a component that can be temporarily removed from a main body of the welding arm, which forms the other of the two opposing boundary walls of the receiving opening for the roller head, for the purpose of mounting or replacing the roller head. This makes it possible to change the roller head in a simple, self-explanatory manner and in a short time.

[0041] A third aspect of the invention relates to a resistance seam welding machine with an arrangement according to the second aspect of the invention.

[0042] A fourth aspect of the invention relates to a roller head for an arrangement according to the second aspect of the invention or for a resistance seam welding machine according to the third aspect of the invention, comprising a stator and an electrode roller which is rotatably mounted on the stator about an axis of rotation, wherein the stator projects beyond the electrode roller on both sides in the direction of the axis of rotation with mounting extensions. The mounting extensions of the stator have flat contact surfaces for attaching the roller head by pressing it against corresponding contact surfaces of a welding arm for a resistance seam welding machine. These contact surfaces extend in planes that are parallel to the axis of rotation of the electrode roller. This design ensures that the stator of the roller head assumes a defined rotational orientation relative to the welding arm when it is mounted on the welding arm.

[0043] This is particularly advantageous when the contact surfaces of the stator's mounting extensions have inlet and outlet openings for a cooling medium, which is preferred for supplying and removing a cooling medium to and from the electrode roller. During assembly, these inlet and outlet openings must be aligned with corresponding inlet and outlet openings on the welding arm. With this embodiment of the roller head according to the invention, this alignment can occur automatically if the welding arm is appropriately designed, thus helping to avoid assembly errors.

[0044] In a preferred embodiment of the roller head, the mounting extensions of the stator, viewed in the direction of the axis of rotation of the electrode roller, each have a circular cross-section with a flattening which forms the contact surface according to the claim.

[0045] A fifth aspect of the invention relates to the use of the arrangement according to the second aspect of the invention for resistance seam welding of the longitudinal seam of can frames. Brief description of the drawings

[0046] The current state of the art and the invention are explained in more detail below with reference to the drawings. These show: Fig. 1 a perspective view of a welding arm for a resistance seam welding machine with a roller head attached to it, in accordance with the state of the art; Fig. 2 a side view of the welding arm from Fig. 1 ; Fig. 3 a vertical section through the welding arm Fig. 1 along line AA in Fig. 1 ; Fig. 4 a perspective view of a first welding arm for a resistance seam welding machine with a roller head attached to it according to the invention; Fig. 5 a top view of the welding arm Fig. 4 ; Fig. 6a side view of the welding arm from Fig. 4 ; Fig. 7 a cut through the sweat arm Fig. 4 along line BB in Fig. 5 ; Fig. 8 a perspective view of a second welding arm for a resistance seam welding machine with a roller head attached to it according to the invention; Fig. 9 a side view of the welding arm from Fig. 8 ; and Fig. 10 a cut through the sweat arm Fig. 8 along line CC in Fig. 8 . Ways to implement the invention

[0047] Figure 1 shows a welding arm for a resistance seam welding machine with a roller head attached to it, as is known from the prior art, in a perspective view.

[0048] Roller heads for resistance seam welding machines are known to those skilled in the art, e.g. from the aforementioned documents DE 40 20 182 C1 and WO 2013 / 181765 A1, and therefore do not need to be described in detail here.

[0049] Such roller heads 1 comprise a stator 3 and an electrode roller 4, which is mounted as a rotor on the stator 3 so as to rotate about an axis of rotation R. The stator 3 projects beyond the electrode roller 4 on both sides in the direction of the axis of rotation R with mounting extensions 5.

[0050] As can be seen, the welding arm 2 has a receiving opening 6 for the roller head 1, which is formed between two opposing parallel boundary walls 7.

[0051] The boundary walls 7 each have circumferentially closed mounting openings 8 for the mounting extensions 5 of the stator 3 of the roller head 1.

[0052] The roller head 1 is arranged in the receiving opening 6 of the welding arm 2 such that the electrode roller 4 protrudes from the receiving opening 6 with part of its circumferential boundary and the fastening extensions 5 are arranged in the fastening receiving openings 8.

[0053] As can be seen from a combination of the Figures 2 and 3 which shows a side view of the welding arm from Fig. 1 show ( Fig. 2 ) as well as a vertical section through the welding arm made of Fig. 1 along line AA in Fig. 1 ( Fig. 3 ), the mounting extensions 5 of the stator 3 are designed as cylindrical axle stubs with a circular cross-section and the roller head 1 is attached to the welding arm 2 by pressing these axle stubs 5 with a curved contact surface 23 formed thereon to an associated curved contact surface 22 within the limits of the respective mounting opening 8.

[0054] The associated curved contact surface 22 is provided by an adapter arrangement 20 located in the respective mounting opening 8, which in turn is pressed against an associated contact surface 10 formed by the boundaries of the respective mounting opening 8 with a contact surface 21 formed thereon.

[0055] The mounting extensions 5 of the stator 3 are each pressed against the corresponding contact surfaces 22 by a clamping piece 11, which is inserted into the respective mounting opening 8. The clamping pieces 11 grip the mounting extensions 5 of the stator 3 from the side opposite the contact surface 23.

[0056] Fig. 4Figure 1 shows a first arrangement according to the invention in the form of a first welding arm according to the invention for a resistance seam welding machine with a roller head according to the invention attached to it in a perspective view.

[0057] As can be seen, the welding arm 2 also has a receiving opening 6 for the roller head 1, which is formed between two opposing parallel boundary walls 7.

[0058] Here too, the roller head 1 comprises a stator 3 and an electrode roller 4, which is mounted as a rotor on the stator 3 so as to rotate about an axis of rotation R. The stator 3 projects beyond the electrode roller 4 on both sides in the direction of the axis of rotation R with mounting extensions 5.

[0059] The boundary walls 7 also each have circumferentially closed mounting openings 8 for the mounting extensions 5 of the stator 3 of the roller head 1 and the roller head 1 is also arranged in the receiving opening 6 of the welding arm 2 such that the electrode roller 4 protrudes from the receiving opening 6 with a part of its circumferential boundary and the mounting extensions 5 are arranged in the mounting openings 8.

[0060] One of the two opposing boundary walls 7 of the receiving opening 6 for the roller head 1, which forms one of the mounting receiving openings 8 for the mounting extensions 5 of the stator 3 of the roller head 1, is formed by a component 17 which can be temporarily removed from a main body 18 of the welding arm 2, which forms the other of the two opposing boundary walls 7 of the receiving opening 6 for the roller head 1, for the purpose of mounting or replacing the roller head 1.

[0061] As can be seen from a combination of the Figures 5 to 7 which shows a top view of the welding arm from above Fig. 4 ( Fig. 5 ), a side view of the welding arm made of Fig. 4 ( Fig. 6 ) as well as a cross-section through the welding arm made of Fig. 4 along line BB in Fig. 5 ( Fig. 7) show that, in this embodiment according to the invention, the fastening extensions 5 of the stator 3 each have a circular cross-section with a flattening which forms the contact surface 9 of the respective fastening extension 5 when viewed in the direction of the axis of rotation R of the electrode roller 4.

[0062] In this embodiment, the associated contact surfaces 10 are formed by the boundaries of the respective mounting opening 8.

[0063] The contact surfaces 9 on the mounting extensions 5 of the stator 3 and the associated contact surfaces 10 on the boundaries of the respective mounting opening 8 run in planes which run parallel to the axis of rotation R of the electrode roller 4 and perpendicular to the longitudinal axis L of the welding arm 2.

[0064] The mounting extensions 5 of the stator 3 are each pressed against the corresponding contact surfaces 10 by a clamping piece 11, which is inserted into the respective mounting opening 8. Here too, the clamping pieces 11 grip the mounting extensions 5 of the stator 3 from the side opposite the contact surface 9.

[0065] However, here the clamping pieces 11 are guided for displacement in the clamping direction by the limits of the mounting openings 8, by directly adjoining associated guide surfaces 13 of the limits of the mounting openings 8 with flat guide surfaces 12 extending in the pressure direction.

[0066] The fastening extensions 5 of the stator 3 and the fastening receiving openings 8 are designed in such a way that the fastening extensions 5 with their contact surfaces 9 can be pressed against the contact surfaces 10 of the boundaries of the fastening receiving openings 8 in different positions.

[0067] The positions are fixed by the clamping pieces 11, in that when the fastening extensions 5 are pressed on, they create both a positive locking with the boundaries of the respective fastening receiving opening 8 in a direction parallel to the plane of the contact surfaces 9 and 10 and also perpendicular to the axis of rotation R of the electrode roller 4, and a positive locking with the respective fastening extension 5 in a direction parallel to the plane of the contact surfaces 9 and 10 and also perpendicular to the axis of rotation R of the electrode roller 4.

[0068] As can be seen, the clamping pieces 11 are designed such that the axis of rotation R of the electrode roller 4 has different distances to the planes in which the flat guide surfaces 12 of the clamping pieces 11 run in the direction of pressure.

[0069] The clamping pieces 11 are also designed in such a way that they can be installed in two different positions, for the selective positioning of the contact surfaces 9 of the mounting extensions 5 of the stator 3 in two different positions on the contact surfaces 10 of the boundaries of the mounting openings 8.

[0070] The clamping pieces 11 are pressed against the mounting extensions 5 of the stator 3 by means of clamping screws 14 fixed in the welding arm 2, in order to press the contact surfaces 9 formed thereon against the associated contact surfaces 10 of the boundaries of the mounting openings 8.

[0071] As from Fig. 7emerges, which makes a vertical cut along line BB in Fig. 5 As shown, the contact surfaces 9 of the mounting extensions 5 of the stator 3 and the associated contact surfaces 10 of the boundaries of the mounting openings 8 have inlet and outlet openings 15, 16 for a cooling medium for the roller head 1. The mounting extensions 5 of the stator 3 are arranged and fastened in the mounting openings 8 such that the inlet and outlet openings 15, 16 overlap in every possible position.

[0072] As can also be seen, seals 24 are arranged in the contact surfaces 10 of the mounting openings 8 to seal the overlapping inlet and outlet openings 15, 16 to the outside.

[0073] Fig. 8Figure 1 shows a second arrangement according to the invention in the form of a welding arm for a resistance seam welding machine with a roller head according to the invention attached to it in a perspective view. This embodiment of the invention represents a retrofit solution for existing welding arms according to the prior art.

[0074] This arrangement, based on its basic concept, demonstrates the structure of the Figures 1 to 3 described arrangement according to the state of the art.

[0075] As seen in the overall view of the Fig. 8 with the Figure 9 and 10 It is recognizable which is a side view of the welding arm. Fig. 8 show ( Fig. 9 ) as well as a cross-section through the welding arm made of Fig. 8 along line CC in Fig. 8 ( Fig. 10) show, however, in this second embodiment according to the invention, the fastening extensions 5 of the stator 3 each have a circular cross-section with a flat flattening in the direction of the axis of rotation R of the electrode roller 4, which forms the contact surface 9 of the respective fastening extension 5.

[0076] In this embodiment, the associated flat contact surfaces 19 are each provided by an adapter arrangement 20 arranged in the respective mounting opening 8, which in turn is pressed against an associated contact surface 10 formed by the boundaries of the respective mounting opening 8 with a contact surface 21 formed thereon.

[0077] The mounting extensions 5 of the stator 3 are each pressed against the corresponding contact surfaces 19 by a clamping piece 11, which is inserted into the respective mounting opening 8. The clamping pieces 11 engage the mounting extensions 5 of the stator 3 from the side opposite the contact surface 9.

[0078] The contact surfaces 9 on the mounting extensions 5 of the stator 3 and the associated contact surfaces 19 on the adapter arrangements 20 run in planes that are parallel to the axis of rotation R of the electrode roller 4 and perpendicular to the longitudinal axis L of the welding arm 2.

[0079] The fastening extensions 5 of the stator 3 and the adapter arrangements 20 are designed in such a way that the fastening extensions 5 with their contact surfaces 9 can be pressed against the contact surfaces 19 of the adapter arrangements 20 in different positions.

[0080] The positions are fixed by the clamping pieces 11, in that when the fastening extensions 5 are pressed on, they create both a positive locking connection with the adapter arrangements 20 in a direction parallel to the plane of the contact surfaces 9 and 19 and also perpendicular to the axis of rotation R of the electrode roller 4, and a positive locking connection with the respective fastening extension 5 in a direction parallel to the plane of the contact surfaces 9 and 19 and also perpendicular to the axis of rotation R of the electrode roller 4.

[0081] As from Fig. 10 emerges, which makes a vertical cut along line CC in Fig. 8As shown, the contact surfaces 9 of the mounting extensions 5 of the stator 3 and the associated contact surfaces 19 of the adapter arrangements 20, as well as the contact surfaces 21 of the adapter arrangements 20 and the associated contact surfaces 10 of the boundaries of the mounting openings 8, have inlet and outlet openings 15, 16 for a cooling medium for the roller head 1. The mounting extensions 5 of the stator 3 and the adapter arrangements 20 are arranged and fastened in the mounting openings 8 such that the inlet and outlet openings 15, 16 overlap.

[0082] As can also be seen, seals 24 are arranged in the contact surfaces 19 of the adapter arrangement 20 and in the contact surfaces 10 of the mounting openings 8, for sealing the overlapping inlet and outlet openings 15, 16 to the outside.

[0083] While preferred embodiments of the invention are described in the present application, it should be clearly pointed out that the invention is not limited to these and can also be carried out in other ways within the scope of the following claims.

Claims

1. Method for fastening a roller head (1) to a welding arm (2) for a resistance seam welding machine, wherein the roller head (1) has a stator (3) and an electrode roller (4) which is supported as a rotor on the stator in a rotatable way about a rotation axis (R), and wherein the stator (3) protrudes over the electrode roller (4) with fastening extensions (5) on both sides of the electrode roller (4) in the direction of the rotation axis (R), comprising the steps: a) providing a welding arm (2) for a resistance seam welding machine comprising a reception opening (6) for the roller head (1), which is formed between two, particularly parallel, limiting walls (7) facing each other, which themselves have fastening reception openings (8) for the fastening extensions (5) of the stator (3) of the roller head (1); b) arranging the roller head (1) in the reception opening (6) for the roller head in such a way that the electrode roller (4) protrudes outside the reception opening (6) with a part of its circumferential boundary and the fastening extensions (5) are arranged inside the fastening reception openings (8); characterized by c) fastening the roller head (1) to the welding arm (2) by pressing each of the fastening extensions (5) of the stator (3) with an even contact surface (9) formed thereon to an attributed even contact surface (10, 19) inside the boundaries of the respective fastening reception opening (8), wherein the contact surfaces (9) of the fastening extensions (5) of the stator (3) and the attributed even contact surfaces (10) have supply and discharge openings (15, 16) for a cooling medium and the fastening extensions (5) of the stator (3) are arranged and fastened in the fastening reception openings (8) for the fastening extensions (5) in such a way that each of the supply and discharge openings (15, 16) overlap at least partially, and wherein each of the fastening extensions (5) of the stator (3) is pressed with a clamping piece (11) received in the respective fastening reception opening (8) with its contact surfaces (9) against the attributed contact surfaces (10, 19).

2. Method according to claim 1, wherein the attributed contact surface (19) is provided by an adapter arrangement (20, 21) arranged inside the respective fastening reception opening (8), which itself is pressed with a contact surface (19) formed thereon on an attributed contact surface (10) formed by the boundaries of the respective fastening reception opening (8).

3. Method according to claim 1, wherein each attributed contact surface (10) is provided by the boundaries of the respective fastening reception opening (8).

4. Method according to claim 3, wherein the contact surfaces (9) at the fastening extensions (5) of the stator (3) and the attributed contact surfaces (10, 19) extend in planes, which are parallel to the rotation axis (R) of the electrode roller (4), and particularly perpendicular to a longitudinal axis (L) of the welding arm (2).

5. Method according to one of the claims 3 to 4, wherein the clamping pieces (11) are guided through the boundaries of the fastening reception openings (8) for an ability to shift in clamping direction.

6. Method according to claim 5, wherein, for guidance, the clamping pieces (11) adjoin, for an ability to shift in clamping direction, attributed guiding surfaces (13) of the boundaries of the fastening reception openings (8) by means of even guiding surfaces (12) extending in pressing direction.

7. Method according to one of the claims 3 to 6, wherein the fastening extensions (5) of the stator (3) and the fastening reception opening (8) are adapted in such a way that the fastening extensions (5) can be pressed with their contact surfaces (9) in different positions on the contact surfaces (10) of the boundaries of the fastening reception openings (8).

8. Method according to claim 7, wherein the positions are set by means of the clamping pieces (11) in such a way that during pressing of the fastening extensions (5) the latter establish a positive fit with the boundaries of the respective fastening reception openings (8) in a direction parallel to the plane of the contact surfaces (9, 10) and perpendicular to the rotation axis (R) of the electrode roller (4) as well as a positive fit with the respective fastening extension (5) in a direction parallel to the planes of the contact surfaces (9, 10) and perpendicular to the rotation axis (R) of the electrode roller (4).

9. Method according to one of the claims 3 to 8, wherein the clamping pieces (11) are pressed against the fastening extensions (5) of the stator (3) by means of clamping screws (14) fastened in the welding arm (2) for pressing the fastening extensions (5) with the contact surfaces (9) formed thereon on the attributed contact surfaces (10, 19).

10. Method according to one of the preceding claims, wherein one of the limiting walls (7) facing each other of the reception opening (6) for the roller head (1), which limiting walls (7) form the fastening reception openings (8) for the fastening extensions (5) of the stator (3) of the roller head (1), is formed by a component (17) which can be temporarily removed from a main body (18) of the welding arm (2), which forms the other one of the two limiting walls (7) of the reception opening (6) for the roller head (1), particularly showing away in the direction of the rotation axis (R) of the electrode roller (4), and wherein this component (17) is removed temporarily for arranging the roller head (1) in the reception opening (6) and is reinstalled after inserting the roller head (1) into the main body (18) in such a way that one of the fastening extensions (5) of the stator (3) of the roller head (1) is arranged inside the fastening reception opening (8) which is formed by the side wall (7) of the main body (18), in such a way that the other fastening extension (5) of the stator (3) is arranged inside the fastening reception opening (8) which is formed by the side wall (7) of the component (17).

11. Arrangement comprising a welding arm (2) for a resistance seam welding machine and a roller head (1) fastened thereon, wherein the roller head (1) has a stator (3) and an electrode roller (4) which is supported as a rotor on the stator (3) in a rotatable way about a rotation axis (R), and wherein the stator (3) protrudes over the electrode roller (4) with fastening extensions (5) on both sides of the electrode roller (4) in the direction of the rotation axis (R), wherein the welding arm (2) has a reception opening (6) for the roller head (1), which is formed between two, particularly parallel, limiting walls (7) facing each other, which themselves have fastening reception openings (8) for the fastening extensions (5) of the stator (3) of the roller head (1), wherein the roller head (1) is arranged inside the reception opening (6) in such a way that the electrode roller (4) protrudes outside the reception opening (6) with a part of its circumferential boundary and the fastening extensions (5) are arranged inside the fastening reception openings (8), characterized in that the roller head (1) is fastened to the welding arm (2) by pressing each of the fastening extensions (5) of the stator (3) with an even contact surface (9) formed thereon to a attributed even contact surface (10, 19) inside the boundaries of the respective fastening reception opening (8), wherein the contact surfaces (9) of the fastening extensions (5) of the stator (3) and the attributed even contact surfaces (10) have supply and discharge openings (15, 16) for a cooling medium and the fastening extensions (5) of the stator (3) are arranged and fastened in the fastening reception openings (8) in such a way that each of the supply and discharge openings (15, 16) overlap at least partially, and wherein each of the fastening extensions (5) of the stator (3) is pressed with a clamping piece (11) received in the respective fastening reception opening (8) with its contact surfaces (9) against the attributed contact surfaces (10, 19).

12. Arrangement according to claim 11, wherein the attributed contact surface (19) in each case is provided by an adapter arrangement (20) arranged inside the respective fastening reception opening (8), which itself is pressed with a contact surface (21) formed thereon on an attributed contact surface (10) formed by the boundaries of the respective fastening reception opening (8).

13. Arrangement according to claim 11, wherein each attributed contact surface (10) is provided by the boundaries of the respective fastening reception opening (8).

14. Arrangement according to claim 13, wherein the contact surfaces (9) at the fastening extensions (5) of the stator (3) and the attributed contact surfaces (10, 19) extend in planes, which are parallel to the rotation axis (R) of the electrode roller (4), and particularly perpendicular to a longitudinal axis (L) of the welding arm (2).

15. Arrangement according to one of the claims 13 to 14, wherein the fastening reception openings (8) are circumferentially closed.

16. Arrangement according to claims 15, wherein the clamping pieces (11) are guided through the boundaries of the fastening reception opening (8) for an ability to shift in clamping direction.

17. Arrangement according to claim 16, wherein, for guidance, the clamping pieces (11) adjoin, for an ability to shift in clamping direction, attributed guiding surfaces (13) of the boundaries of the fastening reception opening (8) by means of even guiding surfaces (12) extending in pressing direction.

18. Arrangement according to one of the claims 13 to 17, wherein each clamping piece (11) engages a fastening extension (5) of the stator (3) from the side opposed to the contact surface (9).

19. Arrangement according to one of the claims 13 to 18, wherein the fastening extensions (5) of the stator (3) and the fastening reception opening (8) are adapted in such a way that the fastening extensions (5) can be pressed with their contact surfaces (9) in different positions on the contact surfaces (10) of the boundaries of the fastening reception opening (8).

20. Arrangement according to claim 19, wherein the positions are set by means of the clamping pieces (11) in such a way that during pressing of the fastening extensions (5) the latter establish a positive fit with the boundaries of the respective fastening reception opening (8) in a direction parallel to the plane of the contact surfaces (9, 10) and perpendicular to the rotation axis (R) of the electrode roller (4) as well as a positive fit with the respective fastening extension (5) in a direction parallel to the planes of the contact surfaces (9, 10) and perpendicular to the rotation axis (R) of the electrode roller (4).

21. Arrangement according to claim 18 and claim 20, wherein the rotation axis (R) of the electrode roller (4) has different distances to the planes in which the even guiding surfaces (12) extending in pressing direction of the clamping pieces (11) run.

22. Arrangement according to claim 21, wherein the clamping pieces (11) are formed in such a way that they can be mounted in two different positions for the optional positioning of the contact surfaces (9) of the fastening extensions (5) of the stator (3) in two different positions on the contact surfaces (10) of the boundaries of the fastening reception openings (8).

23. Arrangement according to one of the claims 13 to 22, wherein each one of the fastening extensions (5) of the stator (3) has a circular cross section with a flattening forming the contact surface (9), as seen in the direction of the rotation axis (R) of the electrode roller (4).

24. Arrangement according to one of the claims 13 to 23, wherein the clamping pieces (11) are pressed against the fastening extensions (5) of the stator (3) by means of clamping screws (14) fastened in the welding arm (2) for pressing the contact surfaces (9) formed thereon on the attributed contact surfaces (10) of the boundaries of the fastening reception openings (8).

25. Arrangement according to one of the claims 11 to 24, wherein seals (24) for sealing the at least partially overlapping supply and discharge openings (15, 16) towards the exterior are arranged in the contact surfaces (10) of the fastening reception openings (8).

26. Arrangement according to one of the claims 13 to 25, wherein one of the two limiting walls (7) facing each other of the reception opening (6) for the roller head (1), which limiting walls (7) form the fastening reception openings (8) for the fastening extensions (5) of the stator (3) of the roller head (1), is formed, for the purpose of mounting or removing the roller head (11), by a component (17) which can be temporarily removed from a main body (18) of the welding arm (2), which forms the other one of the two limiting walls (7) of the reception opening (6) for the roller head (1).

27. Resistance seam welding machine with an arrangement according to one of the claims 11 to 26.

28. Use of the arrangement according to one of the claims 11 to 26 for resistance seam welding of the longitudinal seam of container bodies.