Spindle assembly for a machine tool

Abstract

The invention relates to a spindle assembly of a machine tool, comprising a main spindle (2) having a spindle shaft (3), a spindle housing (4) and exactly one clamping sleeve (8), a first centering interface (6) on the spindle shaft (3) and a second centering interface (7) on the spindle housing (4), wherein the first centering interface (6) is configured to provide a first centering between the spindle shaft (3) and a tool receptacle (100), wherein the clamping sleeve clamps the tool receptacle (100), and wherein the second centering interface (7) is configured to provide a second centering between the spindle housing (4) and a tool receptacle element (5), wherein the clamping sleeve (8) clamps the tool receptacle element (5) in such a way that a gap (10, 11) remains at the first centering interface.

Description

Technical Field

[0001] The present invention relates to a spindle assembly for a machine tool, which has improved application variability by means of an additional centering interface. Background Technology

[0002] Mandrel assemblies for machine tools in various embodiments are known from the prior art. When selecting a machine tool's main mandrel, a trade-off is always sought between the rigidity of the mandrel requiring large ball bearings and the maximum possible rotational speed limiting the bearing size. It is desirable for a main mandrel that is very rigid for machining with large tools and has a high rotational speed for machining with small tools. However, this is technically impossible. Therefore, in practice, so-called auxiliary mandrels are used. These auxiliary mandrels are clamped at the clamping interface of the main mandrel, where tool receivers for different tools are also clamped; this clamping interface is, for example, a hollow taper shank (HSK) clamping interface. However, the rigidity of the connection between the auxiliary mandrel and the main mandrel is thus limited. During operation, undesirable vibrations occur, and the machining quality is often insufficient. Therefore, auxiliary mandrels are rarely used in practice. Summary of the Invention

[0003] The object of the present invention is to provide a mandrel assembly for a machine tool that has a simple design and simpler, more cost-effective manufacturability, enabling the expansion of the possible uses of various tool receiving elements and, in particular, additional mandrels.

[0004] This objective is achieved by a mandrel assembly having the features of claim 1. The dependent claims illustrate preferred improvements of the invention.

[0005] The spindle assembly of the machine tool according to the invention, having the features of claim 1, has the advantage that, in addition to the first centering interface on the spindle body, a second centering interface is also provided on the spindle housing. Therefore, the spindle assembly includes a main spindle having a spindle body and a spindle housing, and exactly one clamping kit disposed on the spindle body. The clamping kit clamps a tool receiving portion, wherein the first centering interface is configured to provide centering between the spindle body and the tool receiving portion. The spindle body is preferably a hollow shaft, and the first centering interface is preferably disposed on the hollow shaft. The clamping kit is preferably a hollow taper shank (HSK) clamping kit. The spindle assembly also includes a second centering interface on the spindle housing. The second centering interface is configured to provide a second centering between the spindle housing and the tool receiving element. In this case, the clamping kit clamps the tool receiving element in a manner that maintains a gap at the first centering interface.

[0006] Therefore, on one hand, the clamping kit clamps the tool receiving part at the first centering interface on the mandrel body, where the second centering interface does not perform a centering function; on the other hand, the clamping kit clamps the tool receiving element at the mandrel housing, where the first centering interface on the mandrel body does not perform a centering function. Thus, a single clamping kit is used to clamp both the tool receiving part and the tool receiving element. A decisive advantage of this invention is that only exactly one clamping kit exists, by which a standard tool can be clamped to the mandrel body via the tool receiving part, and the tool receiving element can be clamped to the mandrel housing.

[0007] The tool receiving element is preferably an additional mandrel or a tool holder. Therefore, a problem previously unresolved in the prior art can be solved in such a way that, when using the first centering interface, the main mandrel clamps a large tool with maximum rigidity, and on the other hand, the tool receiving element, particularly the additional mandrel or other tool, can be operated at high rotational speeds by centering at the second centering interface.

[0008] Therefore, on the one hand, the mandrel assembly according to the invention can be used in the usual manner by centering with a tool at the first centering interface, and on the other hand, it can be operated by centering with an additional mandrel at the second centering interface, in particular.

[0009] Preferably, the first centering interface is a hollow taper shank (HSK) interface. Therefore, the present invention can be used on standardized interfaces that are coupled to hollow mandrel bodies.

[0010] More preferably, the tool receiving element in the region of the first centering interface is configured such that, in the clamped state of the tool receiving element, there is a gap between the first mandrel body and the tool receiving element at the tapered contact surface of the hollow tapered shank interface. More preferably, a second gap is formed between the mandrel body and the tool receiving element at the face seat of the hollow tapered shank interface.

[0011] For particularly compact designs, the spindle assembly is preferably configured such that the second centering interface is disposed on the end face of the main spindle.

[0012] The second centering interface is also preferably disposed on the annular region of the spindle housing, particularly adjacent to the spindle shaft or the labyrinth seal. Multiple connections for power lines and / or signal lines and / or media channels are preferably disposed on the annular region of the spindle housing. These connections are preferably used for supplying additional spindles.

[0013] Preferably, the second centering interface has a centering element that provides a form-fit connection between the main spindle and the tool receiving element. The centering element of the second centering interface is preferably a rib and a groove, particularly having tapered contact surfaces respectively. The rib preferably extends radially relative to the spindle axis. The rib is formed in the spindle housing and / or the tool receiving element, and the groove is formed in the corresponding other components.

[0014] The second centering interface also preferably includes a flat surface as a centering element for axial contact between the spindle housing and the tool receiving element of the main spindle.

[0015] The centering elements of the second centering interface are preferably arranged in the circumferential direction at equidistant positions, and in particular, the four centering elements are arranged at 90° intervals from each other.

[0016] The centering element is preferably disposed on the annular region of the spindle housing, and in particular is inserted into the annular region.

[0017] More preferably, the mandrel assembly includes an activatable support device that establishes and releases the connection between the mandrel housing and the mandrel body of the main mandrel. When the tool receiving element is clamped against the mandrel housing at the second centering interface by the clamping kit, the clamping force of the clamping kit does not act on the mandrel bearing of the main mandrel. When the support device has established a connection between the mandrel housing and the mandrel body, the clamping force of the clamping kit is transmitted from the mandrel body to the mandrel housing via the support device.

[0018] The support device preferably includes a pin and a spring, wherein the spring preloads the pin into a retracted position so that no connection is formed between the spindle housing and the spindle shaft of the main spindle.

[0019] Preferably, the support device engages in a recess formed in the spindle body, or the support device may extend in front of a shoulder on the spindle body.

[0020] More preferably, the first centering interface and the second centering interface are located in a common plane E. This keeps the longitudinal extension of the mandrel assembly as small as possible.

[0021] More preferably, the clamping part of the clamping kit and the second centering interface are both located in a common plane E, or the clamping part intersects with plane E.

[0022] The tool receiving element is preferably an additional mandrel, particularly for small tools that can operate at high rotational speeds, or a tool holder, such as a tool holder for stationary turning tools. The additional mandrel is preferably a complete mandrel with its own drive, wherein the additional mandrel is supported on a smaller diameter than the main mandrel. Attached Figure Description

[0023] Preferred exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings:

[0024] Figure 1 A perspective view of a mandrel assembly with an additional mandrel is shown from a first angle in an exploded view of a preferred exemplary embodiment of the invention.

[0025] Figure 2 Shown from a second perspective Figure 1 Exploded perspective view of the spindle assembly.

[0026] Figure 3 The image shows an assembly with an additional spindle. Figure 1 A schematic cross-sectional view of the mandrel assembly.

[0027] Figure 4 It shows Figure 3 A schematic enlarged partial cross-sectional view of the spindle assembly.

[0028] Figure 5 A schematic partial cross-sectional view of a mandrel assembly with a clamping tool holder is shown, the clamping tool holder being centered only at the second centering interface, and

[0029] Figure 6 A schematic cross-sectional view of the mandrel assembly is shown, in which the tool receiving portion is centered at the first centering interface. Detailed Implementation

[0030] The following is for reference. Figures 1 to 6 A detailed description of a spindle arrangement 1 with various clamping devices according to a preferred exemplary embodiment of the present invention is provided.

[0031] The spindle assembly 1 includes a main spindle 2 having a spindle body 3. The spindle body 3 is mounted on a first bearing assembly 21 and a second bearing assembly 22 (see...). Figure 3 ).

[0032] To secure the first bearing assembly 21 of the main spindle 2, the spindle nut 12 is screwed onto the corresponding external thread on the outer circumference of the spindle body 3. Reference numeral 13 indicates a labyrinth seal used to seal the first bearing assembly 21 of the main spindle 2.

[0033] The spindle body 3 is a hollow spindle. The spindle assembly 1 also includes a clamping kit 8 configured for use with a hollow taper shank (HSK) and located within the spindle body 3. Furthermore, the spindle body 3 includes a first centering interface 6 having a faceplate 81 and a tapered contact surface 80, at which a tool receiving portion configured as a hollow taper shank can be centered. The tapered contact surface 80 is oriented toward the clamping kit 8. The faceplate 81 is oriented perpendicular to the spindle axis (central axis) of the spindle assembly (see [reference]). Figure 4 Therefore, the main spindle 2 has a standardized clamping position.

[0034] Main spindle 2 also includes only Figure 3 and Figure 4 The multi-component spindle housing 4 and driver 20 are schematically shown in the figure.

[0035] The mandrel assembly also includes a second centering interface 7 disposed on the mandrel housing 4. Figure 1 and Figure 2 The second centering interface 7 can be seen in detail. Figure 1 and Figure 2 Two perspective views of the mandrel assembly 1 are shown from different angles. In addition to the main mandrel 2, a tool receiving element 5, which is an additional mandrel 50 in this exemplary embodiment, is also shown.

[0036] The second centering interface 7 includes ribs 70 formed on the additional spindle 50 and grooves 71 formed on the spindle housing 4. In this case, four ribs 70 and four grooves 71 are provided, each offset by 90°.

[0037] The groove 71 is formed in the annular region 40 on the end face of the spindle housing 4, which is also the end face of the main spindle 2.

[0038] In order to supply power and / or signal and / or medium to the additional spindle 50, a plurality of connections 72 are schematically shown in the annular region 40 of the spindle housing 4. These connections may be for power lines and / or signal lines and / or medium channels.

[0039] Therefore, the second centering interface 7 has ribs 70 and grooves 71 as centering elements, wherein a tapered contact surface is preferably formed between the ribs and the grooves. Furthermore, a flat surface 73 is provided on the annular region 40 for centering, wherein the flat surface 73 is formed perpendicular to the mandrel axis XX. A corresponding flat surface 57 is formed on the tool receiving element 5.

[0040] Therefore, the second centering interface 7 has a shape-fitting centering element and a flat centering element (flat surface).

[0041] The first centering interface 6 is configured to provide a first centering between the spindle body 3 and the tool receiving portion 100, such as Figure 6 As shown. Clamping kit 8 clamping tool receiving part 100. As from Figure 6 As can be seen, the second centering interface 7 at the end face of the spindle housing 4 is not functioning.

[0042] Centering via the first centering interface 6 occurs at the tapered contact surface 80 of the hollow tapered shank interface and at the face seat 81 of the hollow tapered shank interface. The tool receiving part 100 itself does not have a driver and is driven via the spindle 2. The tool receiving part 100 receives a tool 101, such as a milling cutter.

[0043] and Figure 6 different, Figure 3 and Figure 4 The use of tool receiving element 5 in the form of an additional mandrel 50 is shown, which can be obtained from... Figure 3 This can be seen in detail.

[0044] The additional spindle 50 includes a driver 52, a first bearing assembly 53, and a second bearing assembly 54. The tool is indicated by reference numeral 55.

[0045] The first bearing assembly 53 and the second bearing assembly 54 are located on the first diameter D1, which is significantly smaller than the second diameter D2. The first bearing assembly 21 and the second bearing assembly 22 of the main spindle are arranged on the second diameter D2.

[0046] This allows the auxiliary spindle 50 to operate at very high rotational speeds, exceeding the maximum rotational speed of the main spindle. Power, signals, and media are supplied via the connection 72.

[0047] When the additional mandrel 50 is clamped against the second centering interface 7 on the mandrel housing 4, a support device 9 is provided to prevent the clamping force of the clamping kit 8 from acting directly on the bearing assemblies 21 and 22 of the main mandrel. The support device 9 includes a pin 90 and a spring 91, wherein the spring 91 holds the pin 90 in the retracted position after releasing the mandrel body 3. For example, by means of compressed air, the pin 90 enters the engaged position, thereby forming a connection between the mandrel housing 4 and the mandrel body 3. In the engaged state, the pin 90 engages in a recess 30, such as an annular groove, which is formed, for example, in the mandrel body 3 (see, in particular). Figure 4 When the additional mandrel 50 is clamped onto the mandrel housing 4, the force of the clamping kit 8 can be transmitted from the mandrel body 3 to the mandrel housing 4 via the pin 90 of the support device 9. In contrast, during machining with the tool receiving portion 100, the tool receiving portion 100 is clamped onto the mandrel body 3 by the clamping kit 8 and centered at the first centering interface 6 on the mandrel body 3, and the pin 90 of the support device 9 is in the retracted position and thus disengaged (see...). Figure 6 ).

[0048] exist Figure 3 and Figure 4 The engagement position of the support device 9 is shown in the diagram. Figure 6 The retracted position of pin 90 is shown in the diagram because... Figure 6 The tool 101 is directly driven by the main spindle 2.

[0049] As from Figure 4 As can be seen in detail, the additional mandrel 50 is clamped onto the annular neck 56 by means of the clamping kit 8. In this case, there is a first gap 10 to the tapered contact surface 80 of the hollow tapered shank interface, and a second gap 11 to the face seat 81 of the hollow tapered shank interface. Therefore, the additional mandrel 50 is centered only at the second centering interface 7 and clamped at the neck 56 by means of the clamping kit 8. The first centering interface 6 is not functional.

[0050] As from Figure 4 As can be further seen, the second centering interface 7 and the clamping portion on the clamping kit 8 are configured in a common plane E. Plane E intersects the tapered contact surface 80 on the hollow mandrel body 3. Therefore, the first centering interface 6 and the second centering interface 7 are located in the common plane E.

[0051] exist Figure 5 In the diagram, a tool holder 51 for holding the turning tool is shown as a tool receiving element 5. Similar to the additional mandrel 50, the tool holder 51 is clamped via a clamping kit 8 and centered only via a second centering interface 7. The first centering interface 6 is inactive. Because relatively high forces and torques must be transmitted for the turning tool, machining accuracy is significantly better when the turning tool is supported on the mandrel housing 4 at the first centering interface 6 rather than on the mandrel body 3.

[0052] Therefore, according to the present invention, different processing devices can be clamped on the main spindle 2 by means of the clamping kit 8 and centered via the first centering interface 6 or the second centering interface 7. Thus, the possible uses of the main spindle can be significantly expanded. In particular, the additional spindle 50 can be securely clamped and centered, and driven at a rotational speed significantly higher than that of the main spindle 2. However, as... Figure 6 As shown, the spindle according to the invention can clamp standard tool receiving parts 100 and center them at the first centering interface 6. Therefore, by providing a second centering interface 7 and using a single clamping kit 8 in conjunction with either the first centering interface 6 or the second centering interface 7, the versatility of the spindle 2 can be significantly increased. Standardized clamping kits 8, such as those provided for hollow tapered shank interfaces, can be used.

[0053] Therefore, the variability of the spindle 2 can be significantly improved by the additional centering interface 7.

[0054] Explanation of reference numerals in the attached figures

[0055] 1 spindle assembly

[0056] 2 spindles

[0057] 2a End face of the main spindle

[0058] 3-spindle body

[0059] 4-spindle housing

[0060] 5 Tool receiving elements

[0061] 6 First centering interface

[0062] 7 Second centering interface

[0063] 8HSK Connected Clamping Kit

[0064] 9 Support devices

[0065] 10 First gap

[0066] 11 Second gap

[0067] 12-pin nut

[0068] 13 Labyrinth Seals

[0069] 20 spindle driver

[0070] 21 First bearing assembly of the main spindle

[0071] 22 Second bearing assembly of the main spindle

[0072] 30 recesses

[0073] 31 External Thread

[0074] 40 ring area

[0075] 50 additional spindles

[0076] 51 Tool Holder

[0077] 52 additional spindle driver

[0078] 53 Additional mandrel first bearing assembly

[0079] 54 Second bearing assembly with additional spindle

[0080] 55 Tools

[0081] 56 neck

[0082] 57 flat surfaces

[0083] 70 ribs

[0084] 71 slots

[0085] 72 Connecting Part

[0086] 73 flat surfaces

[0087] Tapered contact surface of 80HSK interface

[0088] 81HSK interface socket

[0089] 90 sales

[0090] 91 Spring

[0091] 100 Tool Receiving Department

[0092] 101 Tools

[0093] D1 First Diameter

[0094] D2 Second Diameter

[0095] E plane

[0096] XX mandrel axis

Claims

1. A spindle assembly for a machine tool, comprising: - Main spindle (2), which has spindle body (3), spindle housing (4) and exactly one clamping kit (8). - The first centering interface (6) on the spindle shaft (3), and - The second centering interface (7) on the spindle housing (4). - Wherein the first centering interface (6) is configured to provide a first centering between the spindle body (3) and the tool receiving portion (100), wherein the clamping kit (8) clamps the tool receiving portion (100), and - The second centering interface (7) is configured to provide a second centering between the spindle housing (4) and the tool receiving element (5), wherein the clamping kit (8) clamps the tool receiving element (5) in such a way that a gap (10, 11) is maintained at the first centering interface (6).

2. The mandrel assembly according to claim 1, wherein the first centering interface (6) is configured as a hollow tapered shank interface.

3. The mandrel assembly according to claim 2, wherein the tool receiving element (5) is constructed in the region of the first centering interface (6) such that, in the clamped state, a first gap (10) is formed at the tapered contact surface (80) of the hollow tapered shank interface between the mandrel body (3) and the tool receiving element (5) and / or a second gap (11) is formed at the face seat (81) of the hollow tapered shank interface between the mandrel body (3) and the tool receiving element (5).

4. The mandrel assembly according to any one of the preceding claims, wherein the second centering interface (7) is disposed on the end face (2a) of the main mandrel (2).

5. The mandrel assembly according to any one of the preceding claims, wherein the second centering interface (7) is disposed on the annular region (40) of the mandrel housing (4), particularly adjacent to the mandrel shaft (3) or adjacent to the labyrinth seal (13).

6. The spindle assembly according to claim 5, wherein a plurality of connectors (72) for power lines and / or signal lines and / or media channels are disposed on the annular region (40) of the spindle housing (4).

7. The mandrel assembly according to any one of the preceding claims, wherein the second centering interface (7) has a centering element that provides a form-fitting connection between the main mandrel (2) and the tool receiving element (5).

8. The mandrel assembly according to claim 7, wherein the centering element comprises a rib (70) and a groove (71), wherein the rib and the groove have, in particular, tapered contact surfaces.

9. The mandrel assembly according to claim 8, wherein the rib (70) extends in the radial direction relative to the mandrel axis (XX).

10. The mandrel assembly according to any one of claims 7 to 9, wherein the second centering interface (7) further comprises a flat surface (73) as a centering element for axial contact between the main mandrel (2) and the tool receiving element (5).

11. The mandrel assembly according to any one of claims 7 to 10, wherein the centering elements are arranged at equal intervals in the circumferential direction, and in particular, four centering elements are arranged at 90° intervals from each other.

12. The mandrel assembly according to any one of claims 5 to 11, wherein the centering element is disposed in the annular region (40) of the mandrel housing (4).

13. The mandrel assembly according to any one of the preceding claims further includes an activatable support device (9) that establishes and releases the connection between the mandrel housing (4) of the main mandrel (2) and the mandrel shaft (3).

14. The mandrel assembly according to claim 13, wherein the support device (9) comprises a pin (90) and a spring (91), wherein the spring (91) preloads the pin (90) into a retracted position such that no connection is formed between the mandrel housing (4) and the mandrel shaft (3) of the main mandrel (2).

15. The mandrel assembly according to claim 13 or 14, wherein the support device (9) engages in a recess (30) formed in the mandrel body (3), or wherein the support device (9) is capable of extending forward of a shoulder on the mandrel body (3).

16. The spindle assembly according to any one of the preceding claims, wherein the first centering interface (6) and the second centering interface (7) are located in a common plane E.

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