METHOD AND DEVICES FOR PRODUCING ROUGHENED SURFACES

Abstract

The present invention relates to apparatuses and methods for laser treatment, more particularly laser roughening, of surfaces.

Claims

1. Apparatus for laser roughening, the laser treatment being directed to surfaces of a plurality of workpiece openings that are spaced at a distance from one another, which can be the surfaces of cylinder bores or of a single cylinder bore, comprises at least a work station, wherein the work station comprises, on the one hand, at least one laser treatment module having a module axis and, on the other hand, a positioning device via which a relative movement between a workpiece arranged in the work station for treatment and the laser treatment module can be effected, wherein the laser treatment module comprises beam guiding optics which are designed to guide a laser beam for the treatment of the surface in a discharge direction that is inclined relative to the module axis and a plane which is orthogonal to the module axis onto the surface to be treated, and wherein the laser treatment module is designed and arranged in order to rotate the laser beam about the module axis, the laser treatment module comprises a rotation device, which comprises a direct drive being designed as a hollow shaft drive and a rotor of the hollow shaft drive rotatable about an axis of rotation which corresponds to the module axis, the beam guiding optics comprising a collimator unit for collimation of the laser beam coming from a radiation source and a focusing unit for focusing the collimated laser beam, which is held via a sleeve-like element which extends into the rotor and is connected to the housing, as well as a discharge direction-defining beam deflecting device which deflects the laser beam for the treatment of the surface from a main optical direction extending along the module axis in the discharge direction, rotation device is designed to rotate the discharge direction-defining beam deflecting device relative to the collimator unit or relative to the collimator unit and the focusing unit about the module axis in order to effect the rotation of the exiting laser beam about the module axis, the laser treatment module comprising a further beam deflecting device in the optical path upstream of the discharge direction-defining beam deflecting device, and in particular upstream of the focusing unit, which beam deflecting device deflects the laser beam in the main optical direction, wherein the laser treatment module comprises a process gas flow path comprising a portion extending along the main optical direction, the portion being arranged in particular between the first further beam deflecting device and the discharge direction-defining beam deflecting device, and the process gas exiting at the outlet opening, wherein the process gas flow path is designed such that the process gas flows along the outside of the sleeve-like element, which is used to hold the focusing unit.

2. (canceled)

3. (canceled)

4. Apparatus according to claim 1 characterized in that a stator of the hollow shaft drive is connected to a housing of the laser treatment module in a rotationally fixed manner, and a rotor of the hollow shaft drive has an axis of rotation which corresponds to the module axis.

5. Apparatus according to claim 1, characterized in that the laser treatment module comprises a second further beam deflecting device which is designed and arranged to guide the laser beam in an inclined, orthogonal direction relative to the main optical direction, to the first further beam deflecting device.

6. Apparatus according to claim 1, characterized in that the laser treatment module comprises a tapered spindle portion which is designed for insertion into the workpiece opening to be treated, the direct drive being arranged at a distance from the spindle portion designed for insertion into the workpiece opening to be treated when viewed along the module axis.

7. Apparatus according to claim 23, characterized in that the transfer device is designed as a lifting turntable.

8. Apparatus according to claim 23, characterized in that the turntable is designed to transfer at least 2 workpieces from the loading and unloading station to the work station at the same time per transfer process and, at the same time, by means of the same transfer process at least 2 workpieces from the work station to the loading and unloading station.

9. Apparatus according to claim 23, characterized in that the closure device comprises an openable and closable partition wall which has a double-walled structure, a cavity being delimited by an outer wall and the partition wall comprising a sensor unit which is designed and arranged to detect when laser radiation from the laser of the laser treatment module penetrates into the cavity.

10. Apparatus according to claim 23, characterized in that the work space comprises a suction device which is arranged in a treatment position of a workpiece to be treated in the work space of the work station, below a workpiece opening to be treated.

11. Apparatus according to claim 23, characterized in that the apparatus comprises a radiation source compartment which is separate from the work space of the work station and in which a radiation source for providing the laser beam is arranged for the treatment, a light guide being provided in order to guide the laser beam from the radiation source into the work space of the work station.

12. Method for laser roughening particular surfaces (92) of cylinder bores, using an apparatus for laser roughening comprising the steps of: positioning a workpiece to be treated in a work station of the apparatus; positioning a spindle portion of a laser treatment module of the apparatus in the workpiece opening to be treated of the workpiece which is located in the work station; irradiating the surface of the workpiece opening to be treated by means of a continuous, laser beam guided into the workpiece opening via the laser treatment module, wherein the laser beam rotates about the module axis, wherein the laser treatment module comprises beam guiding optics which are designed to guide a laser beam for the treatment of the surface in a discharge direction that is inclined relative to the module axis and a plane which is orthogonal to the module axis onto the surface to be treated, characterized in that a beam deflecting device, which deflects the laser beam for the treatment of the surface in the discharge direction, rotates relative to a collimator unit for collimating the laser beam coming from a radiation source or relative to the collimator unit and a focusing unit for focusing the collimated laser beam about the module axis in order to effect the rotation of the exiting laser beam about the module axis, wherein the positioning of the workpiece to be treated in the work station of the apparatus takes place in a transfer process of a transfer device, a workpiece that has already been treated being removed from the work station at the same time during the transfer process by means of a rotary movement of the transfer device, wherein a closure device which spatially separates the work space from a loading and unloading station is opened to carry out the transfer process, the workpieces, which leave the work station in the transfer process, and the workpieces, which are moved into the work station in the transfer process, passing the closure device spatially at the same time, and the closure device being subsequently closed in order to separate the work space spatially from the loading and unloading station (22).

13. Method according to claim 12, characterized in that the rotational movement of the beam deflecting device is superimposed with a translational relative movement between the workpiece and the beam deflecting device of the laser treatment module, in particular between the workpiece and the laser treatment module, which is directed along the direction of the module axis.

14. Method according to claim 12, characterized in that the laser treatment module comprises a rotation device which is designed to rotate the beam deflecting device relative to the collimator unit or relative to the collimator unit and the focusing unit about the module axis in order to effect the rotation of the exiting laser beam about the module axis, the rotation device comprising a direct drive which, during the treatment process, is arranged outside when viewed in the direction of the module axis, in particular above the workpiece opening of the workpiece to be treated.

15. Method according to claim 12, characterized in that a monitoring of the treatment process takes place at the same time as the laser treatment, for this monitoring, an optical signal coming from the treated surface initially being guided along the optical path of the laser used for the treatment in the laser treatment module and being decoupled from the optical path of the laser beam by means of a beam deflecting device, designed as an interference mirror, and being fed to a sensor connection point.

16. (canceled)

17. Method according to claim 12, characterized in that at least one workpiece having a plurality of openings to be treated is treated by means of the laser, the currently untreated opening being covered during the laser treatment by a cover assigned to the laser treatment module in use.

18. Apparatus according to claim 1, characterized in that one of the further beam deflecting devices decoupling an optical signal coming along the optical path from the workpiece surface along the main optical direction, from the optical path of the laser beam and feeding it to a sensor connection point,

19. Apparatus according to claim 1, characterized in that by means of the positioning device a relative movement between the workpiece arranged in the work station for treatment and the laser treatment module is effectable, which relative movement running in a plane orthogonal to the module axis and/or in the direction of the module axis.

20. Apparatus according to claim 1, characterized in that the positioning device comprises a compound slide arrangement, wherein the laser treatment module is arranged on the slide arrangement.

21. Apparatus according to claim 1, characterized in that the laser treatment module comprise at least one sealing gas device having a sealing gas outlet arranged in the region of the outlet opening of the laser beam, the sealing gas outlet being arranged on the half of the spindle portion including the outlet opening.

22. Apparatus according to claim 1, characterized in that the laser treatment module comprises at least one sealing gas device, which is designed and arranged to conduct sealing gas into the interior of the sleeve-like element in which the focusing unit is held.

23. Apparatus for laser roughening, the laser treatment being directed to surfaces of a plurality of workpiece openings that are spaced at a distance from one another, which are the surfaces of cylinder bores or of a single cylinder bore, comprises at least a work station, wherein the work station comprises, on the one hand, at least one laser treatment module having a module axis and a positioning device via which a relative movement between a workpiece arranged in the work station for treatment and the laser treatment module can be effected, wherein the laser treatment module comprises beam guiding optics which are designed to guide a laser beam for the treatment of the surface in a discharge direction that is inclined relative to the module axis and a plane which is orthogonal to the module axis onto the surface to be treated, and wherein the laser treatment module is designed and arranged in order to rotate the laser beam about the module axis, the beam guiding optics comprising a collimator unit for collimation of the laser beam coming from a radiation source and a focusing unit for focusing the collimated laser beam as well as a discharge direction-defining beam deflecting device which deflects the laser beam for the treatment of the surface from a main optical direction extending along the module axis in the discharge direction, wherein the apparatus further comprises at least one loading and unloading station in which a workpiece to be treated can be loaded into the apparatus and an already treated workpiece can be removed from the apparatus, at least one work station, wherein the work station comprises at least one laser treatment module for the treatment of workpieces in the work station, wherein the apparatus also has a transfer device which is designed to carry out a workpiece transfer between a loading and unloading station and a work station, the transfer device is designed to carry out a transfer process of a workpiece to be treated from the loading and unloading station into the work station by means of a rotary movement, and, at the same time, to carry out a transfer process of a treated workpiece from the work station to the loading and unloading station by means of the same rotary movement, the apparatus further comprising a closure device which is arranged and designed to separate in a shielding state the loading and unloading station from a work space of the work station in a laser-safe manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Further details and characteristics of the present inventions are explained below with reference to the drawing, in which:

[0070] FIG. 1 is a perspective view of an apparatus according to the invention for laser treatment, a housing of the apparatus not being shown;

[0071] FIG. 2 is a sectional view through a schematically illustrated apparatus according to the invention;

[0072] FIG. 3 is a plan view of an apparatus according to the invention, shown schematically, the housing of the apparatus being only partially shown;

[0073] FIG. 4 is a plan view of the housing of the apparatus with partial openings through the housing;

[0074] FIG. 5 shows a laser treatment module as used in the apparatus according to the invention;

[0075] FIG. 6 is a sectional view through a schematic view of the laser treatment module from FIG. 5;

[0076] FIG. 7 is a schematic view of the beam path of the laser treatment module from FIGS. 5 and 6;

[0077] FIG. 8 is a sectional view corresponding to FIG. 6 in which a first sealing gas device or its sealing gas flow is illustrated;

[0078] FIG. 9 is a sectional view corresponding to FIG. 6 in which a second sealing gas device or its sealing gas flow is illustrated;

[0079] FIG. 10 is a sectional view corresponding to FIG. 6, in which a process gas flow path is illustrated;

[0080] FIG. 11 is a schematic view of a partition wall; and

[0081] FIG. 12 is a schematic view of an alternative partition wall.

DETAILED DESCRIPTION

[0082] Corresponding parts and regions bear the same reference signs in the following figures.

[0083] FIG. 1 shows a schematic perspective representation of an apparatus 10 for laser treatment. In the present case, the apparatus is designed for laser roughening of surfaces of a plurality of workpiece openings that are at a distance from one another, in the present case cylinder bores. The apparatus comprises a work station 12 in which workpieces 14 to be treated, which in the present case are formed by cylinder blocks having a plurality of cylinder bores 16, can be subjected to laser treatment.

[0084] The workpieces to be treated are fed to the work station 12 by means of a transfer device 18. In the present case, the transfer device 18 is designed in the form of a turntable.

[0085] The transfer device 18 is designed and arranged such that it can transfer workpieces 14, which are transported to a loading and unloading station 22 via a belt conveyor 20, by means of a rotary movement in a transfer process from the loading and unloading station 22 to the work station 12. At the same time, by means of the transfer device 18, workpieces 14 (which have already been treated) can be moved simultaneously from the work station 12 into the loading and unloading station 22 in the same transfer process.

[0086] In the present case, the apparatus 10 is shown without a housing 24 that is usually present. The apparatus 10 comprises a machine bed 26. In addition to the machine bed 26, the apparatus further comprises a positioning device 28, which in the present case is designed as a slide arrangement 30 (in this case a compound slide arrangement). Two laser treatment modules 32 are arranged on the slide arrangement 30 or the positioning device 28. The laser treatment module 32 and its structure are explained in detail below in connection with FIGS. 5 to 7.

[0087] A relative movement between the laser treatment module or modules 32 and the corresponding workpieces 14 can be brought about by means of the positioning device 28. In the present case, the laser treatment module 32 is moved for this purpose, while the workpieces 14 remain in their position relative to the machine bed 26.

[0088] FIG. 2 shows the apparatus 10 from FIG. 1 in a schematic side sectional view. In FIG. 2, the housing 24 is shown schematically. The housing defines a work space 34 arranged around the work station. In addition to the work space 34, the apparatus 10 further comprises a radiation source compartment 36 which is separate from the work space 34. A radiation source 38 for providing the laser beam provided for treatment, which is coupled into the laser treatment module 32, is arranged in the radiation source compartment 36. The radiation source 38 is connected via a light guide 40 to the laser treatment module 32 for coupling in the laser beam.

[0089] The apparatus 10 has a first suction device 42 which generally vents the work space 34. In addition, the apparatus 10 has a second or a plurality of second suction devices 44 for each laser treatment module 32, each of which has a suction opening below the workpiece openings to be treated in each case. The laser treatment modules 32 each have a diaphragm device 45 which is designed such that it can close any workpiece openings that are arranged at a distance from the opening provided for the treatment. Each laser treatment module 32 can be moved relative to the corresponding diaphragm device 45. The diaphragm device 45 can be placed on the cylinder block 14 and the laser treatment module 32 can be inserted through an opening in the diaphragm device 45 into the workpiece or the cylinder block 14 or the cylinder bore 16.

[0090] As can be clearly seen in FIGS. 2 and 3, the apparatus 10 has a closure device 46 which comprises a partition wall 48 that can be opened and closed. This can be moved vertically or horizontally to open and close. In the present case, the partition wall 48 is designed to be movable in the vertical direction, which is indicated by the double arrow with the reference sign 50 in FIG. 2.

[0091] The work station 12 or the work space of the work station 12 can be separated from the loading and unloading station 22 by means of the closure device 46 or the partition wall that can be opened and closed. In this case, separable means a radiation-safe separation, so that laser beams exiting from the laser treatment module 32 cannot penetrate from the work space into the loading and unloading station 22 if, for example, the laser treatment module 32 is accidentally switched on without a workpiece 14 being provided.

[0092] For this purpose, it is advantageous if the partition wall 48 and other walls have a double-walled structure. In this double-walled structure, a cavity 51 within the partition wall 46 can be delimited by an outer wall 52. The partition wall 46 can comprise a sensor unit 54, which is shown only symbolically in FIG. 3 and is designed and arranged to detect when laser radiation from the laser of the laser treatment module 32 penetrates into the cavity 51 of the partition wall 48.

[0093] The sensor unit 54 can therefore detect if the outer wall of the partition wall 46 is breached by the laser beam and accordingly an emergency shutdown of the laser treatment module 32 can be carried out before both outer walls delimiting the cavity 51 have been completely penetrated by the laser.

[0094] The closure device 46 in combination with the transfer device 18 offers particular advantages of the present apparatus 10. The transfer device 18 can, at the same time, load the work station 12 and unload already treated workpieces from the work station 12 back into the loading and unloading station 22 by means of a rotary movement within a transfer process. To this end, the closure device 46 must be opened. Since the loading and unloading processes can be carried out at the same time, only a minimal opening time of the closure device 46 is necessary for this and a particularly high cycle time and operational safety of the present apparatus 10 are ensured. In order to increase the cycle time even further, it is provided that the transfer device 18, which is designed as a turntable, can transfer, in this case, two workpieces 14 per transfer process from the loading and unloading station 22 to the work station 12 and, vice versa, can transfer two workpieces 14 from the work station 12 to the loading and unloading station 22 at the same time, in the same transfer process.

[0095] The positioning device 28 is designed such that the two laser treatment modules 32 can be used for the treatment of different workpieces 14, but, at the same time, the positioning device 28 also allows the laser treatment modules 32 to be moved such that both laser treatment modules 32 can process the same workpiece 14, for example in adjacent openings. This is also supported by the fact that the laser treatment modules 32 are designed to be particularly slim and space-saving. For this purpose, the laser treatment modules 32 have a special structure that allows a compact design with high precision and reliability at the same time. The laser treatment modules 32 are each constructed as illustrated in FIGS. 5 to 7.

[0096] FIG. 7 shows the basic structure of a beam guiding optics 60 of the laser treatment modules 32. The beam guiding optics 60 have a collimator unit 62. The collimator unit 62 can be set using a corresponding operating device 63 or the diameter of the collimated beam can be set using the operating device 63. The collimator unit 62 can also be designed such that it can be adjusted electromechanically. The beam guiding optics 60 also have a focusing unit 64 which is designed as a focusing lens. In addition to the collimator unit 62 and the focusing unit 64, the beam guiding optics 60 also have a discharge direction-defining beam deflecting device 66. The beam deflecting device 66 defines a discharge direction 90, i.e. the direction in which the laser beam leaves the laser treatment module 32 without further deflection or is directed onto the surface to be treated. The laser beam 86 strikes the discharge direction-defining beam deflecting device 66 along a main optical direction 67, which extends along a module axis 84. The beam guiding optics 60 also comprise a first further beam deflecting device 68 and a second further beam deflecting device 69.

[0097] The first further beam deflecting device 68 deflects the laser beam 86 in the main optical direction 67. The laser beam 86 passes the focusing unit 64 along the main optical direction 67.

[0098] The second further beam deflecting device 69 deflects the laser beam 86 in a direction 71 (in the present case orthogonal) inclined to the main optical direction 67. In the direction 71 which is inclined to the main optical direction 67, the beam strikes the first further beam deflecting device 68.

[0099] FIG. 5 shows the laser treatment module 32 in a side view, the beam guiding optics 60 being arranged in a housing 78.

[0100] The present laser treatment modules 32 are designed such that both the direct drive 72 forming the rotation device 70 and the beam-shaping and deflecting optical components (beam guiding optics 60) are arranged in the laser treatment module 32. This makes the laser treatment modules 32 easy to replace, compact, and damage-resistant. All of the above components can be accommodated in a sealed manner in the laser treatment module 32 and the laser treatment module 32 only has a minimum of connection points (for example a connection point 102 for the light guide 40 for coupling in the laser beam 86). The device can thus be supplemented in a simple manner by further laser treatment modules 32, which, in combination with the transfer device, allows a high degree of flexibility with regard to the clock rate of the apparatus. A plurality of laser treatment modules 32 can thus be provided, each of which can process a plurality of workpieces in order to move the apparatus with a particularly high throughput. The transfer apparatus can convey a plurality of workpieces into the work station per transfer process. On the other hand, if only a small cycle is required, the apparatus can be quasi downgraded, in which, for example, only one workpiece is moved into the work station per transfer process and only one laser treatment module 32 is provided that the individual workpiece openings are treated sequentially.

[0101] In the sectional view of FIG. 6, it is particularly clearly illustrated that the laser treatment module 32 comprises a rotation device 70. The rotation device 70 is implemented in the present case in the form of a direct drive 72, which is designed as a hollow shaft drive 74.

[0102] A stator 76 of the hollow shaft drive 74 is connected non-rotatably to the housing 78 of the laser treatment module 32. A rotor 80 of the hollow shaft drive 74 is arranged in the laser treatment module 32 such that it can rotate about an axis of rotation 82 which coincides with the module axis 84. FIGS. 5 and 6 show a plane 85 arranged orthogonally to the module axis 84.

[0103] When the hollow shaft drive 74 is actuated, the rotor 80 and the components connected thereto are set in rotation about the module axis 84. As a result, the beam deflecting device 66 is set in rotation, so that the collimated and focused laser beam 86 provided for treatment exits in a rotating manner about the module axis 84 in the discharge direction (which is illustrated in this case by the arrow with the reference sign 90) from the laser treatment module 32 and correspondingly strikes a surface 92 of the workpiece opening 16 of the workpiece 14 to be treated.

[0104] The discharge direction 90 is inclined with respect to the module axis 84 and the plane 85 arranged orthogonally to the module axis 84, i.e. it runs relative to both at an angle other than zero degrees (angle a relative to the plane 85 and angle β relative to the module axis 84). Preferably both the angle a as well as the angle β are at least 10°, at least 20°, at least 30°.

[0105] The laser treatment module 32 has a spindle portion 94 which is designed for insertion into the workpiece opening 16 to be treated. The spindle portion 94 comprises an outlet opening 95 for the laser beam 86. The laser beam 86 leaves the laser treatment module 32 in the discharge direction 90 from the outlet opening 95.

[0106] The direct drive 72 or the hollow shaft drive 74, when viewed along the module axis 84, is arranged at a distance from the spindle portion 94, which in turn is designed to be inserted into the workpiece opening 16 to be treated.

[0107] By designing the drive of the laser treatment module 32 as a direct drive 72 or, in the present case, as a hollow shaft drive 74, the laser treatment module 32 can be made very compact. The outlet opening 95 of the laser beam 86 can advantageously be introduced into the workpiece openings 16 to be treated, so that the surfaces of the workpiece openings 16 can be efficiently treated by means of the spindle portion 94, which is arranged rotatably relative to the rest of the housing 78 of the laser treatment module 32 via bearing arrangements 98. By providing a direct drive 72, particularly precise treatment is possible, which is combined with a compact design of the laser treatment module 32. In addition, the apparatus 10 can be equipped with further laser treatment modules 32 in a simple manner, so that the cycle time of the apparatus 10 is very variable or can be increased in a simple manner.

[0108] The direct drive 72 is designed to be offset along the module axis 84 in relation to the spindle portion 94. As a result of the offset arrangement, the spindle portion 94 can be designed such that it does not include any parts of the direct drive 72 and can be designed correspondingly slim.

[0109] During operation of the laser treatment module, the spindle portion 94 can be inserted into the workpiece opening and then the laser beam 86 exiting from the laser treatment module 32 can be rotated in the discharge direction 90 about the module axis 84 by rotating the beam deflecting device 66. A lowering of the laser treatment module 32 into the workpiece opening can be superimposed on this rotation of the laser beam 86. The laser treatment module can generally be moved along the module axis 84 relative to the workpiece (movement of the laser treatment module 32 and/or workpiece 14). This movement can take place step by step, so that the laser treatment is carried out in a quasi-ring shape or continuously, so that a kind of spiral path along the surface of the opening is treated by the laser.

[0110] Since the beam deflecting device 66 is rotated with respect to the other optical components of the system, they can be designed to be rigid and thus space-saving and robust. Only the beam deflecting device 66 is rotated. In the present case, the focusing unit 64 is connected to the housing 78 in a rotationally fixed manner. The focusing unit 64 is arranged within the rotor 80. The focusing unit 64 is held via a sleeve-like element 101 which extends into the rotor 80 and is connected to the housing 78. The sleeve-like element 101 is arranged concentrically to the module axis 84.

[0111] The laser beam is coupled into the laser treatment module 32 via a connection point 102 for the light guide 40. The connection point 102 can be designed and arranged such that the laser beam is initially coupled into the laser treatment module 32 offset (as shown in the figure) or inclined relative to the main optical direction 87. By means of the second further beam deflecting device 69, the laser beam 86 is guided in the present case to the collimator unit 62 and is guided by this to a second further beam deflecting device 68, which in the present case is designed as an interference mirror. The second further beam deflecting device 68 deflects the laser beam 86 onto the focusing unit 64, and from there through the radiolucent sealing unit 100 via the beam deflecting device 66 through the outlet opening 95 onto the surface 92 to be treated. The radiolucent sealing unit 100 is optional.

[0112] The first further beam deflecting device 68 is designed as an interference mirror in order to guide an optical signal coming from the treated surface 92 in the direction of a sensor connection point 104. The first further beam deflecting device 68 guides the optical signal coming from the treated surface 92 along the main optical direction to the sensor connection point 104.

[0113] The radiation-permeable sealing unit 100 is arranged in front of the beam deflecting device 64 along the beam direction and is configured to prevent particles that arise during laser treatment or other contaminants from entering the beam path of the laser treatment module 32.

[0114] The various aspects of the two inventions implemented in the present apparatus 10 can also each be provided individually, but it is particularly advantageous if the aspects of both inventions are implemented in an apparatus according to the invention.

[0115] FIG. 8 shows a sectional view (corresponding to that of FIG. 6), with most of the reference signs not being shown for the sake of clarity. In FIG. 8, a first sealing gas device 106 or its flow path is illustrated. The sealing gas (illustrated by arrows) prevents impurities from getting into the optical path. The sealing gas is introduced into the laser treatment module 32 via a first sealing gas inlet 108. A sealing gas outlet 110 is arranged on the spindle portion 94. The sealing gas outlet 110 is designed to be circular in a circumferential direction U (circumference of the spindle portion). The first sealing gas flow path or the sealing gas device 106 can in particular also be designed such that the sealing gas flows through the gap between the rotor 80 and the stator 76 of the hollow shaft drive of the rotation device.

[0116] The laser treatment module 32 can alternatively or additionally also be designed with a second sealing gas device 112 or a second sealing gas flow path. For the sake of clarity, this is illustrated in FIG. 9. The second sealing gas device 112 is fed with sealing gas via a second sealing gas connection 114. The sealing gas connection 114 is arranged in a portion 116 of the housing 78 in which the collimator unit 62 is arranged. This portion 116 of the housing 78 is designed separately from the portion 118 of the housing 78 which comprises the rotation device 70 (direct drive).

[0117] The sealing gas of the second sealing gas device 112 flows around the collimator 62. The sealing gas of the second sealing gas device 112 fills the sleeve-like element 101 in which the focusing unit 64 is held.

[0118] In FIG. 10, the use of a process gas is illustrated in a representation corresponding to FIGS. 6, 8, and 9. A process gas flow path 120 is designed such that the process gas (illustrated by arrows) flows along the outside of the sleeve-like element 101, which is used to hold the focusing unit 64.

[0119] The laser treatment module 32 of FIG. 10 differs from that shown in FIGS. 6, 8, and 9 in that no sealing unit 100 is provided. The process gas flows continuously through the interior of the spindle portion 94.

[0120] The laser treatment module 32 can be designed such that the process gas flow path 120 is separated from the first sealing gas flow path 106 via a seal 122. The seal 122 can in particular be arranged between a stationary part 124 of the housing 78 and a part 126 of the laser treatment module 32 that can be rotated by the rotation device 70.

[0121] The process gas is introduced into the laser treatment module 32 via a process gas inlet. It flows around the outside of the sleeve-like element 101. It flows inside the spindle portion 94. The process gas leaves the laser treatment module 32 via the outlet opening 95. The outlet opening 95 is configured such that it forms a type of nozzle which directs the exiting flow of the process gas onto the point on the workpiece surface that is treated by the laser beam. The process gas can thus serve as a kind of protective gas when treating the surface.

[0122] The partition wall 46 having the cavity 51 is illustrated in FIG. 11. The partition wall 46 has the outer wall 52, which in turn comprises a first side surface 52a and a second side surface 52b, which together delimit the cavity 51.

[0123] A closure device 46 according to the invention is schematically illustrated in FIG. 12, in which the partition wall is connected to the transfer device 18 and is opened and closed via its rotary movement.