Components of a Machine Tool for Automated Collet Chuck Maintenance and Cleaning

Abstract

The invention relates to a spindle (1) of a machine tool, in particular a machine tool for machining workpieces, as well as to other components of a machine tool for in particular automatedly maintaining and cleaning collet chucks. To this end, the spindle (1) has a connecting plate (100) for connecting the spindle (1) to a compressed air unit and a lubricant supply of a machine tool, a shank element (110) that can be displaced in the longitudinal direction (L) of the spindle (1) and is mounted in the connecting plate (100) of the spindle (1), as well as a spindle shank (121) that can be rotated in the circumferential direction (U) of the spindle (1), with a connecting piece (124) for connecting a connecting element (202) of a collet chuck (200) set up to receive a processing tool or a maintenance tool (300) to the spindle. The shank element (110) has a through hole (113) in the longitudinal direction (L) of the spindle (1), wherein the connecting plate (100) has a lubricant inlet (105) for connection to the lubricant supply, and at least one separate compressed air inlet (104) for connection to the compressed air unit. The connecting plate is set up to fluidically connect the through hole (113) of the shank element (110) to the at least one compressed air inlet (104) as well as the lubricant inlet (105).

Claims

1. A spindle (1) of a machine tool for machining workpieces, comprising: a connecting plate (100) for connecting the spindle (1) to a compressed air unit and a lubricant supply of the machine tool; a shank element (110) configured to be displaced in the longitudinal direction (L) of the spindle (1) and is mounted in the connecting plate (100) of the spindle (1); a spindle shank (121) configured to be rotated in the circumferential direction (U) of the spindle (1), and has a connecting piece (124) for connecting a connecting element (202) of a collet chuck (200) set up to receive a processing tool or a maintenance tool (300) to the spindle, wherein the shank element (110) has a through hole (113) in the longitudinal direction (L) of the spindle (1), wherein the connecting plate (100) has a lubricant inlet (105) for connection to the lubricant supply, and at least one separate compressed air inlet (104) for connection to the compressed air unit, and wherein the connecting plate is set up to fluidically connect the through hole (113) of the shank element (110) to the at least one compressed air inlet (104) as well as the lubricant inlet (105).

2. The spindle (1) according to claim 1, wherein the connecting plate (100) has a lubricant line (108), wherein the lubricant line protrudes into the through hole (113) of the shank element (110).

3. The spindle (1) according to claim 2, wherein the lubricant line (108) has at least one guide element (117), wherein the at least one guide element (117) has recesses and/or regionally abuts against an inner surface (116) of the through hole (113) of the shank element (110).

4. The spindle (1) according to claim 1, wherein the shank element (110) has a multipart, preferably two-part, design, wherein the parts of the shank element (110) are connected with each other by being screwed together.

5. The spindle (1) according to claim 1, wherein the shank element (110) of the spindle (1) is arranged so that it can be displaced relative to the lubricant line (108) in a longitudinal direction (L) of the spindle (1).

6. The spindle (1) according to claim 1, wherein the connecting plate (100) of the spindle (1) has at least one additional compressed air inlet (106) for connection to the compressed air unit, wherein the shank element (110) of the spindle (1) is arranged so that it can be displaced in the longitudinal direction (L) of the spindle (1) by a compressed air supply that takes place via the at least one additional compressed air inlet (106).

7. The spindle (1) according to claim 1, wherein the connecting plate (100) is discoidal, wherein at least one of the compressed air inlets (104, 106) and/or the lubricant inlet (105) is formed on an outer circumferential surface (103) of the discoidal connecting plate (100).

8. A collet chuck (200) for connecting a spindle according to claim 1, the collet chuck comprising: a clamping element (201) set up in particular for clamping a tool; and a connecting element (202) set up in particular for connecting the collet chuck (200) to a connecting piece (124) of the spindle (1), wherein the clamping element (201) and the connecting element (202) are arranged one behind the other in the longitudinal direction (L) of the collet chuck (200), wherein the clamping element (201) and the connecting element (202) each have a through hole (203, 204), wherein the through hole (204) of the clamping element (201) is set up to receive the tool, and has clamping surfaces (205), and wherein the clamping surfaces (205) of the clamping element (201) are set up to abut against a tool clamped into the clamping element (201), characterized in that the through hole (204) of the clamping element (201) and the through hole (203) of the connecting element (202) together form a through channel (203, 204) through the collet chuck (200).

9. The collet chuck (200) according to claim 8, wherein the through channel of the collet chuck is set up to establish a flow connection with the through hole (113) of the shank element (110) of the spindle (1) just as soon as the collet chuck (200) is connected to the spindle (1).

10. The collet chuck (200) according to claim 8, wherein the connecting element (202) of the collet chuck (200) is at least regionally arranged inside of the clamping element (201) of the collet chuck (200), wherein the clamping element (201) is arranged so that it can be displaced in the longitudinal direction (L) of the collet chuck relative to the connecting element (202), in particular against a spring force of a spring arranged between the clamping element and the connecting element.

11. The collet chuck (200) according to claim 10, wherein the through channel of the collet chuck has a sealing element (206), wherein the sealing element (206) in particular seals an area lying between the connecting element (202) and the clamping element (201) in relation to the through channel (203, 204).

12. A maintenance tool (300) for the collet chuck (200) according to claim 8, the maintenance tool comprising: a rod element (301) with an outer surface and a through hole (302) that runs along the longitudinal axis of the rod element, wherein the through hole (302) of the maintenance tool (300) is set up to form a flow connection with the through channel of the collet chuck (200) as soon as the maintenance tool (300) is arranged in the through channel of the collet chuck (200).

13. The maintenance tool according to claim 12, wherein the outer surface of the rod element (301) has a sealant (305), for example a rubber lip, wherein the sealant (305) is set up to seal clamping surfaces (206) of the collet chuck (201) as soon as the maintenance tool (300) is arranged in the through channel of the collet chuck (200).

14. The maintenance tool (300) according to claim 12, wherein the rod element (301) has a catch tank (307) at one end, or is set up to be arranged in a catch tank, wherein the through hole (302) of the rod element (301) is set up to be fluidically connected with the catch tank (307).

15. The maintenance tool (300) according to claim 14, wherein the rod element (301) of the maintenance tool (300) is rotatably mounted relative to the catch tank (307).

16. The maintenance tool (300) according to claim 14, characterized in that the rod element (301) of the maintenance tool (300) is mounted so that it cannot rotate relative to the catch tank (307).

17. The maintenance tool (300) according to claim 12, wherein the catch tank (307) has at least one permeable filter fleece (310).

18. A processing station of a machine tool having the spindle according to claim 1, a collet chuck (200) connected to the spindle (1) according to claim 8, a maintenance tool (300) according to claim 12, a compressed air unit connected to a compressed air inlet (104) of the spindle (1), and a lubricant supply connected to the lubricant inlet (105) of the spindle (1), wherein the processing station further comprises a drive unit, which is set up to rotate the spindle (1), as well as a control unit, and wherein the control unit is set up to actuate the processing station in at least two operating modes, a first operating mode, for example for processing workpieces, and a second operating mode, for example for maintaining the processing station, characterized in that the compressed air unit of the spindle (1) in the first operating mode supplies compressed air in a first pressure stage, in particular for blowing out foreign bodies, and wherein the compressed air unit and the lubricant supply of the spindle sequentially or simultaneously supply lubricant and compressed air in at least one second stage in the second operating mode, in which the maintenance tool is introduced into the through channel of the collet chuck (200).

19. The processing station according to claim 18, wherein a shank element (110) of the spindle (1) is further repeatedly displaced in the longitudinal direction (L) of the shank element (110) of the spindle (1) in the second operating mode, as a result of which the connecting element (202) of the collet chuck (200) connected to the spindle is displaced relative to the clamping element (201) of the collet chuck (200) in the longitudinal (L) direction of the shank element (110).

20. The processing station according to claim 18, wherein the spindle shank (121) of the spindle (1) rotates with changing rotational speeds in the second operating mode, as a result of which the collet chuck (200) of the processing station connected to the spindle shank (121) rotates with varying rotational speeds.

21. The processing station according to claim 18, wherein the control unit acquires at least one of the following pieces of information: a time at which the processing station is operated in the second operating mode; a number and/or a duration of operation of the processing station in the second operating mode; and a supplied quantity of lubricant during the operation of the processing station in the second operating mode.

22. A method for maintaining a collet chuck (200) of a processing station according to claim 18, wherein the method for maintaining the collet chuck (200) comprises the following steps: checking whether a through channel of the collet chuck (200) according to one of claims 8 to 11 has a tool for processing workpieces; bringing out the tool, if present; introducing a maintenance tool (300) according to one of claims 12 to 17 into the through channel of the collet chuck (200); supplying compressed air and/or lubricant via a through hole of a shank element (110) of a spindle (1) according to one of claims 1 to 7 of the processing station into the collet chuck (200); and removing the maintenance tool (300) from the through channel of the collet chuck (200).

23. A method for maintaining a collet chuck (200) according to claim 22, characterized in that the method additionally comprises at least one of the following steps: displacing the shank element (110) of the spindle (1) of the machine tool in the longitudinal direction (L) of the shank element (110); rotating the spindle shank (121) of the spindle (1) with a changing rotational speed; determining the time at which the method is implemented; determining the implementation of the method; determining the duration of the method; and determining the supplied lubricant quantity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The invention will be described in more detail below based on exemplary embodiments and drawings. All described and/or graphically illustrated features here constitute the subject matter of the invention, whether taken separately or in any combination, regardless of how they are summarized in the claims or referenced.

[0060] Schematically shown on:

[0061] FIG. 1 is a side, sectional view of an embodiment of a spindle according to the invention with connected collet chuck according to the invention;

[0062] FIG. 2 is a side view of a connecting plate of a spindle according to the invention;

[0063] FIG. 3 is a side, sectional view of a connecting plate of a spindle according to the invention with lubricant line;

[0064] FIG. 4A is a side, sectional view of a first embodiment of a shank element of a spindle according to the invention;

[0065] FIG. 4B is a side, sectional view of an alternative embodiment of a shank element of a spindle according to the invention;

[0066] FIG. 4C is a top view of the side of the collet chuck-side outlet of the shank element according to FIG. 4B;

[0067] FIG. 5 is a side, sectional view of a lubricant lien with guide elements;

[0068] FIG. 6A is a top view of a first embodiment of a guide element of a lubricant line;

[0069] FIG. 6B is a top view of an alternative embodiment of a guide element of a lubricant line;

[0070] FIG. 7 is a side, sectional view of a collet chuck according to the invention;

[0071] FIG. 8A is a side, sectional view of a first embodiment of a maintenance tool according to the invention;

[0072] FIG. 8B is a side, sectional view of a second embodiment of a maintenance tool according to the invention with catch tank; and

[0073] FIG. 8C is a side, sectional view of another embodiment of a maintenance tool according to the invention with catch tank.

DETAILED DESCRIPTION

[0074] Exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0075] The FIGS. 1 to 8C described below sequentially depict a spindle with connected collet chuck (FIG. 1), the components of a spindle in detail (FIGS. 2 to 6B), a collet chuck 200 (FIG. 7), and three embodiments of a maintenance tool 300 (FIGS. 8A and 8C).

[0076] Further, an arrow L in all figures points in the longitudinal direction of the respective inventive component of a machine tool or a processing station, i.e., in the longitudinal direction of the spindle, in the longitudinal direction of the collet chuck or in the longitudinal direction of the maintenance tool. Moreover, an arrow U points in the circumferential direction, wherein the circumferential direction is synonymous with the rotational direction of a collet chuck and a tool clamped herein, if the collet chuck is connected according to the invention to the spindle shank of the spindle of a processing station.

[0077] A spindle 1 according to the invention comprises a preferably disk-shaped connecting plate 100 with a first upper surface 101, which is set up to be connected to a processing station of a machine tool. Moreover, the spindle 1 shown on FIG. 1 comprises an actuator element 126 as well as a stator 122, which is arranged rotationally fixed around a spindle shank 121. The side of the spindle shank 121 facing away from the connecting plate 100 has a connecting piece 124, which is set up to connect a collet chuck 200 to the spindle 1. While a workpiece is being processed, a processing tool is clamped into the collet chuck 200. The spindle shank 121 arranged inside of the stator 122 subsequently rotates in the circumferential direction U, as a result of which the collet chuck 200 rotates, and thus also the workpiece. In order to be able to secure the spindle shank 121 in the stator 122 against falling out, the spindle 1 has a spindle cover 123 on the side facing the connecting plate.

[0078] The interior of the spindle shank 121 has a recess 125, in which a shank element 110 is arranged. The actuator element 126 is set up to induce an axial displacement of the shank element 110. To this end, a pneumatic actuator element has undepicted pressure chambers and seals, so as to axially displace the shank element 110 controlled by air. The shank element 110 is mounted on the one end side in the connecting plate 100 so that it can be axially displaced in the longitudinal direction L of the spindle, and bumps up against the collet chuck 200 on the opposing end side. The interior of the shank element 110 has a through hole 113, in which a lubricant line 108 is arranged. The through hole 113 can be supplied with compressed air from a compressed air unit via a compressed air inlet 104, and the lubricant line 108 can be supplied with lubricant from a lubricant reservoir via a lubricant inlet 105. The lubricant line 105, in particular a capillary tube, can be guided in the through hole 113 of the shank element 110 with the help of guide elements 117.

[0079] In order to open the collet chuck 200, the shank element 110 is displaced in the longitudinal direction, and thereby displaces a connecting element 202 relative to the clamping element 201 against the force of a spring pack 210. In the opened state, a tool can be introduced into the collet chuck 200 or removed from it. In particular with the help of the spring force of the spring pack 210, the collet chuck 200 can subsequently be reset, and thereby switched into a closed state. While processing a workpiece or while maintaining the collet chuck 200, the connecting plate 100 can always be used to carry compressed air or lubricant via the corresponding channels (compressed air inlet 104, lubricant inlet 105, through channel 107, lubricant line 108, through hole 113, through channel 203, 204).

[0080] The connecting plate 100 shown on FIG. 2 and in an alternative configuration on FIG. 3 has a second lower surface 102, which is oriented in the direction of a shank element 110 of a spindle 1 depicted on FIG. 4A and FIG. 4B. In a state where a collet chuck 200 is connected to the spindle 1, the lower surface 102 thus points in the direction of this collet chuck 200. The side view of the disk-shaped connecting plate 100 on FIG. 2 here shows a circumferential surface 103 of the connecting plate 100 especially well, so that the compressed air inlet 104 arranged on the circumferential surface 103, the lubricant inlet 105 and another compressed air inlet 106 become especially well visible.

[0081] In the case of a pneumatic actuator element 126, the pressure chambers of this actuator element can be filled with compressed air via the compressed air inlet 106. As a result, the inner structure of the actuator element consisting of several chambers can be moved together with the beveled shank element 110 relative to the outer shell of the actuator element 126, and thus induce an axial displacement of the shank element.

[0082] In an exemplary embodiment of the connecting plate 100 according to FIG. 3, the lubricant inlet 105 can be connected to a lubricant line 105 via a through channel 107. On the shank element side, the lubricant line 108 protrudes from a cylinder bore 109 of the connecting plate 100. On the machine tool or processing station side, the lubricant inlet 105 of the connecting plate 100 can be connected to a lubricant supply, so that lubricant can flow out of a lubricant reservoir of the machine tool into the lubricant inlet 105. The compressed air inlet 104 is connected to a compressed air unit on the machine tool side, and thus set up to allow compressed air flowing from the machine tool to flow into the connecting plate 100. If the connecting plate 100 has no lubricant line 108, the compressed air from the compressed air inlet 104 and the lubricant from the lubricant inlet 105 flows in the direction of the cylinder bore 109 of the connecting plate 100, and possibly accumulates here. The compressed air inlet 104 and the lubricant inlet 105 are here used in particular to supply compressed air and lubricant for maintaining the collet chuck 200, wherein the compressed air inlet 106 is used in particular for pneumatically activating or displacing the shank element 110 of the spindle 1 mounted in an axially displaceable manner in the connecting plate 100.

[0083] As shown on FIG. 4A, the shank element 110 can to this end abut with a stop 111 against the first lower surfaces 102 of the connecting plate 100 in a first position, wherein a connecting element 112 of the shank element 110 is arranged inside of the cylinder bore 109 of the connecting plate 100. In this position of the shank element 110, the collet chuck 200 is closed. As soon as compressed air flows into the connecting plate 100 via the compressed air inlet 106 and exposes the connecting element 112 of the shank element 110 to compressed air, the shank element 110 is displaced in a longitudinal direction of the shank element away from the connecting plate 100. This movement of the shank element can be transferred to a connecting element 202 of a corresponding collet chuck 200 and open the latter. If the collet chuck 200 has a spring or a spring pack 210 for the restoring force, the connecting element 202 of the collet chuck 200 is then displaced automatically as soon as the compressed air abates, thereby closing the collet chuck 200.

[0084] FIG. 4B shows an alternative configuration of a shank element 110, which consists of two parts that can be connected with each other using conventional connection techniques. In the area of the collet chuck-side outlet 115, the through hole 113 is divided into five passages, which together form the through hole of the shank element. The embodiment shown on FIG. 4C shows that a lubricant line 108 runs in the central through hole, wherein four additional through holes are arranged around this central through hole. Consequently, a compressed air flow that flows from the connecting plate-side inlet 113 in the direction of the collet chuck-side outlet 115 is divided into four partial air flows in the area of the collet chuck-side outlet 115. In this embodiment, the guiding function for the lubricant line 108 is ensured by the reduced diameter of the through hole in which the lubricant line 108 is guided in the area of the collet chuck-side outlet 115. For example, if the shank element 110 according to the embodiment on FIGS. 4B and 4C is displaced in the longitudinal direction L of the shank element away from the connecting plate 100, this can take place pneumatically by exposing the surface of the shank element to pressure in the area of the connecting plate-side inlet 114 (not shown on FIG. 4B, since FIG. 4B shows only sections of a shank element, wherein the part in the direction of the connecting plate-side inlet was omitted).

[0085] In order to supply the collet chuck with compressed air and lubricant, the compressed air can thus flow via the compressed air inlets 104, 106, the through channels 107 and the cylinder bore 109 into a through hole 113 running in a longitudinal direction of the shank element 110 via a connecting plate-side inlet 114 in the direction of a collet chuck-side outlet 115. Regardless of whether the lubricant is likewise suppled to the cylinder bore 109 via a through channel 107 or carried directly into the through hole 113 of the shank element 110 via a lubricant line 108, the lubricant can also flow in the direction of the collet chuck-side outlet 115 of the through hole 113 via the connecting plate-side inlet 114.

[0086] If the spindle according to the invention has a lubricant line 108, the latter can be abutted and supported against an inner surface 116 of the through hole 113 via guide elements 117 (see FIGS. 1, 5, 6A and 6B). Alternatively, the lubricant line 108 can be guided as described previously and shown on FIGS. 4B and 4C. If the shank element 110 of the spindle is displaced in the longitudinal direction, the at least one guide element 117 glides along the inner surface 116 of the through hole 113, or the guide element 117 glides along the lubricant line 108. In the alternative embodiment according to FIGS. 4B and 4C, the lubricant line 108 glides along the area with a reduced diameter of the through hole 113.

[0087] In order for the guide elements 117 arranged inside of the through hole 113 not to block the through hole 113 and to allow compressed air and/or lubricant to pass, the guide elements have the shape depicted on FIG. 6A or FIG. 6B, for example, wherein only contact surfaces 118 of the guide elements 117 abut against the inner surface 116 of the through opening 113 of the shank element 110. Arranged between the contact surfaces 118 of the guide element 117 are protrusions 119, at which the guide element does not abut against the inner surface 116 of the through hole 113, so that the compressed air flowing in through the connecting plate-side inlet 114 can flow past the guide elements 117 with the help of the protrusions 119 and possibly an opening 120. As an alternative to the embodiments shown on FIGS. 6A and 6B, the guide element can also be designed in the form of a circular ring, and have corresponding recesses through which the compressed air can flow. In this case, the guide element would completely abut against the inner surface 116 of the through hole 113. Moreover, the guide element 117 has an opening 120 for a lubricant line 108, so that the guide element 117 can be put over the lubricant line 108, wherein the lubricant line need not necessarily abut against the opening 120. For example, the guide elements 117 can also be immovably fixed in relation to the shank element 110, and displaced with the shank element 110 axially relative to the lubricant line 108. By way of the lubricant line 108, the lubricant gets directly into the interior of the through hole 113 of the shank element 110, or directly into a through channel of the collet chuck 200, and is here moved in the direction of the collet chuck 200 with the help of an air flow and/or by gravitational force.

[0088] The collet chuck 200 comprises a clamping element 201 and a connecting element 202, wherein the clamping element 201 shown on FIG. 7 and the connecting element 202 are fixedly connected with each other. Both the clamping element 201 and the connecting element 202 each have a through hole 203, 204. The through holes 203, 204 together form a through channel, so that in particular compressed air and/or lubricant flowing into the collet chuck 200 can flow completely through the collet chuck 200. Located inside of the through hole 204 of the collet chuck 200 are clamping surfaces 205, which are set up to clamp a tool, in particular a tool for processing workpieces. Furthermore, a sealing element 206 is arranged in the clamping element 201. The sealing element 206 is used in particular given a displaceable collet chuck, i.e., given a collet chuck in which the clamping element 201 is arranged so that it can be displaced in relation to the connecting element 202 in the longitudinal direction L of the collet chuck 200, for the purpose of sealing an intermediate space between the connecting element 202 and the clamping element 201. Furthermore, a maintenance tool not shown here can be introduced into the through hole 204 of the clamping element 201, and in particular be placed in the sealing element 206, so that the through hole 203 can be connected directly to a through hole 302 shown on FIGS. 8A to 8C in the upper area of the collet chuck 200. The collet chuck further 200 has a drilled sleeve 207. Instead of the threaded sleeve, conventional collet chucks often have grub screws, which prevent a transfer of compressed air and lubricant from an upper area (see through hole 203) of the collet chuck to the lower area (see through hole 204) of the collet chuck by blocking the through channel shown here.

[0089] As soon as the collet chuck 200 has been connected to the spindle, the compressed air as well as the lubricant can flow out the collet chuck-side outlet 115 via the through hole 113 of the shank element 110 and into a spindle-side inlet 208 of the collet chuck 200, and flow out of an outlet 209 of the collet chuck 200.

[0090] During maintenance, i.e., while the machine tool or processing station is being actuated in a second operating mode, a maintenance tool 300 according to FIGS. 8A to 8C can be introduced into the through hole 204 of the collet chuck 200. Such a maintenance tool 300 comprises a rod element 301, and is essentially set up to route the lubricant and the compressed air along with any other foreign bodies present past the clamping surfaces 205 of the collet chuck 200. The rod element 301 has a tubular body with a through hole 302, wherein the lubricant and the compressed air flow in through the collet chuck-side inlet 303 and flow out through the outlet 304. The depicted rod elements 301 comprise a sealant 305 on the collet chuck side, which, as soon as the maintenance tool 300 has been introduced into the collet chuck 200, is set up in particular to seal the clamping surfaces 205 of the collet chuck 200. An outlet-side rod element 306 is located on the side opposite the sealant 305. The outlet-side rod element 306 preferably has a metallic material, which in particular can extend over the entire length of the rod element 301, and can be provided with a sealant 305 only on the outer surface (see FIG. 8C). If the maintenance tool 300 is clamped in a collet chuck 200, the sealant 305 preferably seal the clamping surfaces 205, so that they are not wetted with lubricant.

[0091] Depending on the design of the maintenance tool 300, the outlet 304 can also empty into a catch tank 307, in which the maintenance tool 300 is mounted, wherein the catch tank 307 is connected to the maintenance tool (see FIGS. 8B and 8C). Alternatively, the maintenance tool 300 is initially introduced and clamped in the collet chuck 200, and subsequently introduced into a catch tank 307, wherein the maintenance tool 300 can rotate relative to the catch tank 307 (see FIG. 8A). Regardless of whether the catch tank 307 is already connected with the maintenance tool 300 during the use of a maintenance tool 300 or only connected with the later during maintenance, the catch tank 307 has a bearing 308 that defines the interface between the maintenance tool 300 and the catch tank 307. Depending on the selected bearing 308, the rod element 301 can thus rotate relative to the catch tank 307, or even only rotate together with the catch tank 307.

[0092] The catch tank 307 shown on FIG. 8B has a box shape with side walls 309, wherein one of the side walls 309 comprises a filter fleece 310. The maintenance tool 300 according to FIG. 8C also exhibits a catch tank 307 with a filter fleece 310. As soon as the maintenance tool 300 is introduced into a collet chuck 200 for maintenance, the rod element 301 can be rotated dependently or independently of the catch tank 307. The compressed air flowing out of the maintenance tool 300, including the lubricant particles and possible foreign bodies, is collected in the catch tank 307, wherein the filter fleece 310 can be used to filter the lubricant out of the compressed air flowing through the filter fleece 310. The filter fleece 310 is preferably designed in such a way that it can be changed and replaced by a new filter fleece in the catch tank 307.

[0093] During the operation of a machine tool or a processing station, in particular during the operation of a fully automated machine tool with at least one processing station and with a control unit, the control unit can actuate the processing station in two operating modes. While the processing station is operating in the first operating mode, in which the processing station is set up to process a workpiece, the spindle is connected to the processing station, wherein the collet chuck 200 is connected to the spindle, and holds a tool for processing, for example a drill, between the clamping surfaces 205 of the clamping element 201 of a collet chuck 200. As soon as a drive unit, for example a motor, rotates the spindle or the spindle shank 121, the collet chuck 200 also rotates, and thus so too does the tool for processing the workpiece. During operation in the first operating mode, compressed air of a compressed air unit can flow into the spindle or the shank element 110 via a compressed air inlet 104 of a connecting plate 100 of the spindle 1, and from here flow into the collet chuck 200 via a through hole 113 of the shank element 110. In particular, the air flow can here serve as seal air, so that it protects the through channel of the collet chuck against the undesired entry of foreign bodies. If the processing station is now operated in the second operating mode for maintaining the collet chuck, the compressed air of the compressed air unit can flow into another compressed air inlet 106, and displace the shank element 110 of the spindle in a longitudinal direction of the spindle.

[0094] If the connecting element 202 is arranged so that it can be displaced relative to the clamping element of the collet chuck 200 in a longitudinal direction of the collet chuck 200, this relative movement can be used to open the collet chuck, widen the clamping surfaces 205 and release the clamped tool. A maintenance tool 300 can subsequently be introduced into the through hole 204, and the spindle can be supplied with compressed air via the compressed air inlet 104 and with lubricant via the lubricant inlet 105. As soon as the maintenance tool is arranged inside of the through hole 204, the clamping surfaces 205 are sealed. The clamping surfaces 205 of the collet chuck are thus protected against contaminants, so that the oil-air mixture can now enter into the collet chuck through the through hole 113 of the shank element 110 via the spindle shank-side inlet 208 of the collet chuck 200, become distributed here, and exit again through the through hole 302 of the maintenance tool 300. While the compressed air unit and the lubricant supply of the machine tool are being used to introduce lubricant and compressed air into the collet chuck and to clean and lubricate the collet chuck, i.e., maintain it, the collet chuck 200 connected to the spindle 1 can additionally be rotated, thereby distributing the lubricant assisted by centrifugal force. The collet chuck 200 can likewise be opened and closed with the help of the previously described motion of the rod element 110 in the longitudinal direction of the spindle 1, making it possible to additionally support lubricant distribution. The maintenance tool 300 is then preferably secured against falling out with the sealant 305 in the sealing element 206. Alternatively, the collet chuck can only be opened or closed once the maintenance tool 300 has been removed from the collet chuck, wherein the maintenance tool 300 is previously held in the collet chuck 200 with the help of the clamping surfaces 205. During maintenance, the maintenance tool 300 thus carries the compressed air flow directly past the clamping surfaces 205, and filters the compressed air flow, possibly with the help of a filter fleece 310 arranged in a catch tank 307.

[0095] As a consequence, the present invention enables a fully automated maintenance of a machine tool, which in particular involves the introduction of compressed air and lubricant into a collet chuck of a spindle. Moreover, the structure of the spindle, collet chuck and maintenance tool also allows a targeted, partially automated maintenance, for example in which the maintenance tool is manually inserted into the collet chuck, and the lubricant and compressed air are automatedly supplied.