TURNING DEVICE, USE OF A HYDROSTATIC BEARING AND METHOD FOR TURNING A WORKPIECE

Abstract

For a turning machine (1) that can be used for rotary turning, the tool holder (20) is hydrostatically mounted. A method corresponding to this is described, and it is provided to use a hydrostatic bearing (8, 9) for the damping of mechanical vibrations of a tool holder (20) and/or for the permanent mounting of a tool holder (20) of a turning machine (1).

Claims

1. A turning machine (1) for machining a workpiece (14), the turning machine comprising: a motor (4), which drives a shaft (2) about an axis of rotation (3); a tool holder (7, 20), which is rotationally connected to the shaft (2) and which is rotatable about the axis of rotation (3); and a hydrostatic bearing (8, 9) by which the tool holder (7, 20) is hydrostatically mounted by means.

2. The turning machine (1) as claimed in claim 1, wherein the tool holder (7, 20) comprises as a tool revolver (7, 20) that includes at least two tools (10, 11) that are adapted to be exchangeable by rotation of the tool revolver (7, 20) about the axis of rotation (3).

3. The turning machine (1) as claimed in claim 1, wherein the hydrostatic bearing (8, 9) is at least one of arranged or configured such that mechanical vibrations of the tool holder (7, 20) that are generated by at least one of the workpiece (14) during turning machining or the motor (4) are dampened.

4. The turning machine (1) as claimed in claim 1, wherein the hydrostatic bearing (8, 9) is arranged on a mechanical connection path between the motor (4) and the tool holder (7, 20), the mechanical connection path forming a main transmission path of mechanical vibrations that are generated by the motor and transmitted to the tool holder (7, 20).

5. The turning machine (1) as claimed in claim 1, wherein the hydrostatic bearing (8, 9) is arranged on the shaft (2).

6. The turning machine (1) as claimed in claim 1, wherein the hydrostatic bearing (8, 9) comprises a bearing (8, 9) that imparts permanent hydrostatic mounting.

7. The turning machine (1) as claimed in claim 1, wherein the hydrostatic bearing (8, 9) imparts hydrostatic mounting of the tool holder (7, 20) along at least two linearly independent spatial directions, said hydrostatic mounting being imparted at least one of radially or axially in relation to the axis of rotation (3).

8. The turning machine (1) as claimed in claim 1, further comprising a tool (10, 11) on the tool holder, the tool is shaped such that the workpiece (14) can be machined during a rotational movement of the tool holder (7, 20), and the tool (10, 11) being movable relative to the tool holder (7, 20).

9. The turning machine (1) as claimed in claim 1, wherein at least one of the shaft (2) or the axis of rotation (3) is oriented parallel to an axis of rotation (17) of a workpiece spindle (15) of the turning machine (1).

10. A method of damping mechanical vibrations of a tool holder (7, 20) of a turning machine (1), the method comprising: providing a hydrostatic bearing (8, 9) by which the tool holder is hydrostatically mounted; and damping the mechanical vibrations being generated by at least one of a workpiece (14) during turning machining thereof or a motor (4) of the turning machine (1) that are being transmitted to the tool holder (7, 20).

11. The method of claim 10, further comprising permanently mounting the tool holder (7, 20) using the hydrostatic bearing (8, 9).

12. A method for turning machining of a workpiece (14) on a turning machine, the method comprising: hydrostatically mounting the tool holder (7, 20); and machining the workpiece (14) while the tool holder (7, 20) of the turning machine (1) is rotated.

13. The method as claimed in claim 12, wherein the tool holder (7, 20) is hydrostatically mounted permanently, during the turning machining of the workpiece (14) and during an exchange of a tool (10, 11).

14. The method as claimed in claim 12, wherein the tool holder (7, 20) is hydrostatically mounted such that mechanical vibrations of the tool holder (7, 20) that are generated at least one of by the workpiece (14) during turning machining or by the motor (4) are dampened.

15. The method as claimed in claim 12, further comprising damping mechanical vibrations generated by the motor (4) that are transmitted to the tool holder (7, 20), wherein a main transmission path of the generated mechanical vibrations is distinguished, and the mechanical vibrations are dampened on the main transmission path by the hydrostatic mounting.

16. The turning machine (1) as claimed in claim 5, wherein the hydrostatic bearing (8, 9) is arranged spatially between the motor (4) and the tool holder (7, 20).

17. The turning machine (1) as claimed in claim 1, wherein the tool holder (7, 20) is permanently hydrostatically mounted during at least one of machining of the workpiece (14) or an exchange of a tool (10, 11).

18. The turning machine (1) as claimed in claim 1, wherein the motor (4) is configured to effect a tool feed of the tool holder (7, 20) during turning machining of the workpiece (14).

19. The turning machine (1) as claimed in claim 1, wherein the hydrostatic bearing (8, 9) acts as a damping member (19).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention will now be described in more detail on the basis of one or a few exemplary embodiments, but is not restricted to these few exemplary embodiments. Further exemplary embodiments will emerge from combination of the features of individual or multiple patent claims with one another and/or with individual or further features of the exemplary embodiments.

[0023] In the FIGURE:

[0024] The sole FIGURE shows an exemplary embodiment of a turning machine 1 according to the invention.

DETAILED DESCRIPTION

[0025] The turning machine 1 illustrated in the FIGURE may be used in particular for rotary turning with high machining accuracy.

[0026] For this purpose, the turning machine 1 has a workpiece 14 which is clamped into a tailstock 16 and which can be set in rotational motion by the tool spindle 15. In an alternative exemplary embodiment, the workpiece 14 is not additionally clamped into a tailstock 16. In the exemplary embodiment shown in the FIGURE, the workpiece rotates, for the machining thereof, about the rotational axis 17 of the tool spindle 15. Furthermore, a device (not illustrated in any more detail) is designed for the three-dimensional translational movement of the workpiece 14.

[0027] In alternative exemplary embodiments, the workpiece 14 may be clamped, and/or capable of being set in linear and/or rotational motion, in some other way, wherein embodiments may also be provided in which a translational movement of the workpiece 14 can be effected only along fewer than three spatial directions, or else cannot be effected at all. A translational movement may for example also be effected by mobility of a tool 10, 11 relative to the tool holder 20.

[0028] In the exemplary embodiment shown in the FIGURE, a shaft 2 can be set in rotational motion about the axis of rotation 3 by a motor 4, which has a stator 5 and a rotor 6. Here, the axis of rotation 3 and thus also the shaft 2 are oriented parallel to the rotational axis 17. Here, the motor 4 is designed to effect a tool feed of the tool revolver 7 during turning machining of the workpiece 14.

[0029] In further exemplary embodiments, the axis of rotation 3, which constitutes a pivot axis, may also be oriented perpendicularly or in some other way relative to the rotational axis 17 of the workpiece 14.

[0030] A tool holder 20 in the form of a tool revolver 7 is rotationally connected to the shaft 2 in the FIGURE such that the tool revolver 7 can be set in rotational motion about the axis of rotation 3 by the motor 4. The tool revolver 7 has a multiplicity of tools 10, 11, of which only two tools 10, 11 are explicitly illustrated in the FIGURE. In the situation shown in the FIGURE, the tool 10 is presently provided for machining the workpiece 14. The workpiece 14 can be machined owing to the rotation of the workpiece 14 and the contact with the tool 10, 11.

[0031] The FIGURE shows, by way of example, two tools 10, 11, which are configured for machining a radially oriented workpiece surface. Instead of or in addition to these tools 10, 11, use may also be made of tools which permit machining of an axially oriented workpiece surface.

[0032] Rotary turning is achieved by virtue of the workpiece 14 being rotated and machined while the tool revolver 7 is rotated. Furthermore, during the machining, the workpiece 14 and the tool 10 are moved relative to one another along the axis of rotation 3 and thus also along the rotational axis 17. Thus, the relative movement of the tool 10 with respect to a fixed point of the workpiece 14 describes a three-dimensional curve. It can also be stated that the tool 10 performs a pivoting movement during the workpiece machining. Correspondingly, the cutting edge of the tool 10 can be shaped so as to describe a segment of the three-dimensional curve.

[0033] The tool 10, 11 can be exchanged by virtue of the tool revolver 7 being correspondingly rotated onward.

[0034] The shaft 2 and thus the tool revolver 7 are permanently hydrostatically mounted by means of the hydrostatic bearings 8, 9. Here, the hydrostatic bearings 8, 9 are arranged and configured such that the pivoting movement of the tool 10, 11 that is performed during the workpiece machining is hydrostatically mounted, such that mechanical vibrations are dampened. The hydrostatic bearings 8, 9 thus act in each case as a damping member 19. Thus, firstly, mechanical vibrations of the tool revolver 7 that are generated by the motor 4 are dampened, and secondly, mechanical vibrations of the tool revolver 7 that are generated by the workpiece 14 during the turning machining are also dampened.

[0035] The hydrostatic bearings 8, 9 are each of annular form. They each fully surround the shaft 2.

[0036] Here, the hydrostatic bearing 8 is arranged spatially between the motor 4 and the tool revolver 7. The further hydrostatic bearing 9 is arranged on the shaft 2 on the opposite side of the tool revolver 7 as viewed from the motor 4. The shaft 2 and the tool revolver 7 are mounted exclusively by the two hydrostatic bearings 8, 9. In alternative exemplary embodiments, mounting may also be realized partially by non-hydrostatic means, for example by virtue of only the bearing 8 being designed as a hydrostatic bearing 8.

[0037] In the exemplary embodiment shown in the FIGURE, the stator 5 of the motor 4 and the hydrostatic bearings 8, 9 are in each case mechanically connected by a mechanical connection 13 to the housing 12 of the turning machine 1. In the exemplary embodiment shown in the FIGURE, the hydrostatic bearings 8, 9 are in each case arranged on a mechanical connection path between the motor 4 and the tool revolver 7. Here, said mechanical connection path forms a main transmission path of mechanical vibrations that are generated by the motor 4 and transmitted via the stator 6 of the motor 4 to the tool revolver 7.

[0038] The shaft 2 has two annular attachments 18 which are enclosed by the hydrostatic bearings 8, 9. In this way, hydrostatic mounting, and thus vibration damping, are imparted along two special directions that are oriented perpendicular to one another. Hydrostatic mounting and thus damping are thus realized radially and axially in relation to the axis of rotation 17.

[0039] It is provided, in the case of a turning machine 1 that can be used for rotary turning, for the tool holder 20 to be hydrostatically mounted. A method corresponding to this is described, and it is provided to use a hydrostatic bearing 8, 9 for the damping of mechanical vibrations of a tool holder 20 and/or for the permanent mounting of a tool holder 20 of a turning machine 1.

LIST OF REFERENCE DESIGNATIONS

[0040] 1 Turning machine [0041] 2 Shaft [0042] 3 Axis of rotation [0043] 4 Motor [0044] 5 Stator [0045] 6 Rotor [0046] 7 Tool revolver [0047] 8 Hydrostatic bearing [0048] 9 Further hydrostatic bearing [0049] 10 Tool [0050] 11 Further tool [0051] 12 Housing [0052] 13 Mechanical connection [0053] 14 Workpiece [0054] 15 Workpiece spindle [0055] 16 Tailstock [0056] 17 Rotational axis of 15 [0057] 18 Attachment [0058] 19 Damping member [0059] 20 Tool holder