EP3475028A1

EP3475028A1 - Release unit for a machine tool spindle

Info

Publication number: EP3475028A1
Application number: EP17748753.5A
Authority: EP
Inventors: Joachim Van Sprang; Michael Bergbaur; Matthias SCHEFFOLD
Original assignee: Franz Kessler GmbH
Current assignee: Franz Kessler GmbH
Priority date: 2016-09-09
Filing date: 2017-08-03
Publication date: 2019-05-01
Also published as: CN109689285A; US20190210118A1; DE102016116927A1; TW201815496A; WO2018046202A1

Abstract

The invention relates to a release unit (1) for a machine tool spindle, in particular a motor spindle, for releasing a tool clamp, wherein the release unit (1) comprises at least one adjustment element (16) that can be adjusted in a linear manner along an adjustment path (H) for actuating the tool clamp, which reduces the construction and/or operational output. According to the invention, this is achieved in that the release unit (1) is designed as an electric motor (2) having an electromagnetic drive system (8, 10) and having a hollow-cylindrical rotor shaft (9) rotating about an axis of rotation (14), in that the linearly adjustable adjustment element (16) is designed as a spindle element (16) of a conversion unit (13) for converting the rotation of the electric motor (2) into a linear movement (H), and in that the rotor shaft (9) is designed as a spindle nut (9) of the conversion unit (13) rotating about the axis of rotation (14).

Description

"Release unit for a machine tool spindle"

The invention relates to a release unit for a

Machine tool spindle according to the preamble of claim 1

State of the art

In machine tools, especially in milling machines or the like, tool clamps are very often used, which allow an automatic tool change. This means the tool is so with the shaft

Machine tool spindle connected, that it can be solved automatically. For clamping used in the vast majority of cases tool clamps, which usually with a

Spring package, etc. are connected. The resulting

Tension is transmitted via the pull rod on collet segments, which in turn the tool with the shaft

connect .

To release the pull rod and thus the plate-spring package is acted upon with an axially acting release force, which compresses the springs together and thus allows axial displacement of the tie rod, which in turn leads to a release movement of the clamping segments in the tool holder. The necessary for releasing axial force is called so-called

Dissolving units generated. This is usually a piston-cylinder system, which is pressurized on one side. This pressure multiplied by the area of the piston acts as a release force via a pressure contact on the drawbar. The pressure required to release the tool is either hydraulically generated (usually in the range of about 80 to 140 bar) or when using pneumatic release units compressed air is used (usually 5 to 6 bar), which is not only energy-intensive in hydraulic systems but it can also be dangerous for leaks.

Thus, from DE 199 37 447 AI already a release unit for a machine tool spindle, in particular motor spindle, known, which is designed as a hydraulic release unit and thus a hydraulic connection, in particular a

Hydraulic oil connection, has. A disadvantage of such hydraulic or pneumatic

Dissolving units is also that in addition to the electrical connection for the motor spindle or the electromagnetic

Drive system of the motor spindle in addition to provide a hydraulic or pneumatic power supply. This means for the operator of a corresponding

Machine tool a correspondingly high design and financial expense.

Objects and advantages of the invention

The object of the invention is in contrast, to propose a release unit for a machine tool spindle, in particular motor spindle, the constructive and / or

reduced business expenses.

This object is, starting from a release unit of the type mentioned, by the features of claim 1 solved. The measures mentioned in the dependent claims are advantageous embodiments and refinements of

Invention possible. Accordingly, an inventive invention

Dissolution unit characterized in that the release unit as a

Electromagnetic drive system comprehensive electric motor is formed with a rotating about an axis of rotation, cylindrical rotor shaft that the linearly adjustable

Adjusting element as a spindle element of a conversion unit for converting the rotation of the electric motor into a

Linear adjustment is formed and that the rotor shaft as rotating about the rotation axis of the spindle nut

Implementation unit is formed.

With the help of such designed as an electric motor release unit, wherein the rotor shaft is also the spindle nut of the conversion unit, a particularly space-saving electrical release unit can be realized. Thus, in the area of space often very limited in machine tools or space such as the tool or workpiece facing away area of a machine tool spindle or motor spindle, i. at the "rear" end face of the machine tool spindle or

Motor spindle, the space-saving electric release unit according to the invention are arranged in an advantageous manner.

With the space-saving electrical according to the invention

Release unit can be replaced in an advantageous manner a previously existing small-sized, hydraulic release unit. Consequently, according to the invention, a separate

hydraulic or pneumatic power supply for the

Machine tool spindle or motor spindle are omitted. That means that too

Pressure generating unit for generating the hydraulic pressure or pneumatic pressure is unnecessary, especially for the

Machine tool manufacturer and the

Machine tool operator. This allows a

economically particularly advantageous operation of a inventive machine tool or

Motor spindle / machine tool spindle.

Thus, the trained according to the invention, linearly adjustable adjusting element or spindle element of the replaced

Reaction unit the previously existing, fluid-operated

Piston rod, the tensioner or the

Tool clamp actuated, in particular triggers. Consequently, previously common or standardized tool clamping components corresponding machine tool spindle / motor spindle

can still be used without these being changed or adapted to the advantageous electrical release unit according to the invention.

In addition, already existing or

manufactured and even used for a long time in operation machine tool spindles / motor spindles according to the invention um- / retrofitted. This means that, for example, in the event of a defect or maintenance of the previous hydraulic release unit, the advantageous electrical release unit according to the invention can be installed. This is therefore of particular advantage, not only for newly manufactured

Machine tool spindle / motor spindles, but also for already in use machine tool spindles.

For example, the electrical release unit according to the invention has a connection flange, which essentially corresponds to a connection flange of previous hydraulic / pneumatic release units, so that, for example, a

Screwing the electrical release unit by means of

advantageous connection flange can be realized.

Previously common hydraulic release units often have a rotary feedthrough or a media feedthrough for coolants and / or lubricants or the like, so that

The end face of one end of the release unit corresponding medium or coolant and lubricant or the like by the release unit and by the advantageous spindle element according to the invention through the tool clamp or up to the tool / workpiece is durchleitbar. The corresponding

Connections can in turn correspond to the hitherto customary connections of hydraulic release units, so that no adjustment of the media feedthrough system is necessary here. This reduces the effort for the integration of

Electrical release unit according to the invention or increases the compatibility of the electrical release unit according to the

Invention with hitherto conventional dissolving units for

Machine tool spindles / motor spindles.

Preferably, the rotor or spindle nut is coaxial with respect to the spindle element or linearly adjustable

Adjusting arranged, in particular also a centrally arranged media passage / line or a channel is also arranged coaxially thereto.

Due to the design of the hollow cylindrical rotor shaft as a spindle nut of the conversion unit is achieved in an advantageous manner that the electric motor as an advantageously compact unit at the same time has the conversion unit. This means that in the electrical release unit according to the invention not only the function of an electric motor

integrated, but at the same time the implementation of the

Rotational movement of the electric motor in a linear adjustment or Linearverstelleinheit / linear drive, resulting in a special compact, space-saving design of the electrical release unit according to the invention. By the

Dual function of the electrical release unit, on the one hand as an electric motor and on the other hand as a linear drive, is also a reduction of the used, needed

Components / components achieved, which is not only constructive, but also economically favorable. Furthermore, a high positioning accuracy of

Spindle element by the formation of the rotor shaft as a spindle nut of the conversion unit by the

direct drive according to the invention or achieved by that Tolerances or the total tolerance can be minimized / is.

Advantageously, the rotor shaft of the electric motor is designed as a magnetic carrier element comprising at least one permanent magnet of the drive system. This causes the permanent magnets of the electromagnetic

Drive system directly on the rotor shaft or the

Spindle nut are arranged or fixed. This means that the permanent magnets according to the invention on / at the

Outside / surface of the rotor shaft are arranged or

at least partially the outward / pointing

Form surface of the rotor shaft. If necessary

Fixing provided for secure fixation of the permanent magnets on the rotor shaft. This can be, for example

Bandages and / or an adhesive layer or an adhesive or the like.

Preferably, the rotor shaft of the electric motor comprises at least one thread, in particular can also several

Threads are provided. This means that the / the

Threads are arranged according to the invention on / on the inside / surface of the rotor shaft or at least partially form the inward / facing surface of the rotor shaft. Consequently, the rotor shaft advantageously has an internal thread of the conversion unit. Thus, the thread or threads as internal thread of the rotor shaft in

Advantageously in the rotor shaft / spindle nut of the

Electric motor introduced according to the invention or

be incorporated.

Just by using a plurality of threads, which are arranged in an advantageous manner next to each other, a relatively large pitch of the thread /

Threads are achieved, allowing a favorable

Implementation of the rotational movement is realized in a linear adjustment. This can be advantageous, since so far corresponding release units perform relatively fast axial strokes, in particular about 0.5 to 3 cm long Stroke in approx. 0.01 to 0.3 seconds with a release force of approx. 10 to 60kN. With the aid of the electrical release unit according to the invention, this can be achieved, for example, by comparatively high rotational speeds of several thousand

Revolutions per minute and / or by an advantageous

Increase of the thread or the threads can be realized.

Basically, very different thread forms or

Threads can be provided, for example, metric or trapezoidal thread as well as ball screw or the like. Preferably, a comparatively small / small pitch of the thread (s) is provided, which advantageously leads to a relatively large / strong feed force or release force.

So is in principle conceivable that the thread of the

Rotor shaft or spindle nut of the conversion unit directly in contact with the corresponding thread of the

Spindle element is. In a particular embodiment of the invention rolling elements between the spindle nut and the spindle element are arranged. Thus, the conversion unit according to the invention in an advantageous manner as a roller screw, in particular planetary roller screw, or preferably designed as a ball screw. Especially with such

Screw drives are a very high linear

Feed rate and relatively large

Feed forces reachable, wherein the driving electric motor according to the invention is comparatively small and thus

save space can be formed.

Due to the advantageous use of rolling elements between the spindle nut and the spindle element is achieved that the friction between the rotational component or the

Spindle nut and the linearly adjustable, esp. Non-rotating spindle element compared to a direct or immediate drive mode (ie without rolling elements) is significantly reduced, resulting in a corresponding small and energy-efficient design of the electromagnetic drive system of the electric motor leads. This is advantageous because, especially with the use of hitherto usual tool clamps or release / clamping components corresponding machine spindles / motor spindles, esp.

Belleville spring packs, a relatively large release force, e.g. about 45kN, in the direction of the axial adjustment of the

Is to generate adjusting element. This standardized, generally unchangeable release force, by a

Dissolving unit is to be generated can be generated in an advantageous manner by reducing the friction losses within the release unit or within the conversion unit of the electromagnetic drive system of the electric motor of the release unit according to the invention. This means that the electric motor according to the invention of the release unit is comparatively small due to an advantageous reduction of the internal friction losses by means of the advantageous rolling elements, in particular balls

dimensionable and thus not only space-saving, but also energy-efficient can be used.

In the formation of the conversion unit as

Planetenrollengewindetrieb the rolling elements are substantially formed as rollers, each having axes of rotation which are each arranged as parallel to the axis of rotation of the spindle member and the rotor shaft. Optionally, an advantageous gear or the like is present to a common drive mode of the approximately in the circumferential direction

to achieve evenly around the spindle element arranged rollers. Thus, the rollers and / or the advantageous gear are advantageously driven by the spindle nut or the rotor shaft according to the invention or are in direct contact with the rotor shaft. Thus, the conversion unit is advantageously as planetary roller screw

can be trained.

In an advantageous embodiment of the invention, the conversion unit is designed as a ball screw, wherein the rolling elements are formed as balls. This will be the constructive as well as economical effort clearly

reduced. Thus, in addition, an advantageous reduction of the outer diameter of the conversion unit or the

Spindle nut / rotor shaft feasible. Thus, in this embodiment of the invention the conversion unit is achieved, that the spindle nut is arranged very close to the spindle element, since the trained as balls rolling elements in each case substantially just half in the thread of the spindle nut on the one hand and on the other hand in the corresponding thread of the spindle element or fill it accordingly , Thus, a significant reduction of the realizable or minimum outer diameter of the conversion unit is achieved in comparison to a roller screw drive. This is achieved because in the roller screw the thread of the spindle nut is comparatively far spaced from the thread of the spindle element or in between the respect.

Balls are arranged comparatively large sized rollers.

So is the training of the implementation unit as

Ball screw of particular advantage, since not only a particularly low friction can be realized, but at relatively low drive power of

electromagnetic drive system or the electric motor relatively high feed rates or

Linear adjustments can be achieved. In addition, a ball screw is characterized by a high

Positioning accuracy or a low stick-slip behavior. Also is a very low wear of one

Ball screw realized, so that a particularly long life is achievable.

Advantageously, the rotor shaft of the electric motor comprises at least one return or a return channel to

Returning the rolling elements or balls. Preferably, the return or the / the return channels between the / the

Permanent magnet of the drive system and the /

Threads arranged. So can advantageously the Rolling or balls again one or more turns are returned or transported, insofar as they migrate in operation in the axial direction. Optionally, at least one sealing element is provided on the spindle nut and / or rotor shaft and / or on the thread (at the end) which, as a stop, moves out or "falls out"

Prevent rolling elements / balls.

Preferably, for storage of the rotor shaft

electromagnetic drive system of the electric motor between a first bearing and at least one second bearing

arranged. This can be an advantageous storage of

Rotor shaft to be generated. In any case, one of the bearings as a storage unit with two

Rolling, in particular two ball bearings, formed, which are realized in so-called X or 0 arrangement. This can be absorbed not only radially but also axially forces in an advantageous manner.

Preferably, at least one of the bearings is as

Tapered roller bearing formed. This ensures that a recording of relatively large axial and radial forces can be realized with a single roller bearing. This means that hereby an axial / radial bearing with only a single roller bearing is feasible, so that very little space is required for this storage.

In an advantageous variant of the invention, the

Storage of the spindle element, the rolling elements between a first sliding bearing or first spindle bearings and arranged at least a second sliding bearing or second spindle bearings. With the help of the two spindle bearings or plain bearings

allows the linear movement of the spindle element or of the adjusting element realized in an advantageous manner in the longitudinal direction of the axis of rotation, esp. Can slide. Preferably (each) is an advantageous seal or at least one

Sealing element / sealing ring per slide bearing provided. For example, at least one of the spindle bearings as rolling bearings, esp. Ball / roller bearings, for the storage of

Spindle element formed opposite the rotor shaft or spindle nut. Preferably, the rotor shaft comprises at least a first sliding surface of the first sliding bearing and / or a stator of the electric motor at least a second sliding surface of the second sliding bearing. In an advantageous variant, the first slide bearing is arranged on a first end section or a first stop element for striking the tool clamp and / or the second slide bearing on

arranged opposite end portion or at the tool facing end of the spindle member and in contact with the stator of the electric motor. Due to the advantageous, relatively large spacing of the two plain bearings a very precise alignment or storage / arrangement of the spindle element can be realized.

Advantageously, the first and / or second bearing of the rotor shaft is designed at least as an axial bearing of the spindle element for receiving forces oriented in the direction of the axis of rotation. So that is in an advantageous way

Tapered roller bearing of the rotor shaft as thrust bearing of the

Spindle element formed. Accordingly, the first or the second bearing of the rotor shaft, in particular the

Tapered roller bearings, the forces for releasing the tool clamp, which are axially aligned, on the spindle element. In addition, in an advantageous manner, the forces by means of the spindle nut and / or rolling elements and thus to the bearing of the rotor shaft in operative connection or are advantageously weiter- / derived, so that they advantageously from the existing bearing of the rotor shaft, in particular from

Tapered roller bearings of the rotor shaft can be recorded. This reduces the cost of storage of the rotor, or the rotor shaft, since this storage at the same time for the radial / axial mounting of the adjusting element or

Spindle element is used. This is not only a reduction of the required storage components, but also achieved a reduction of the required space in an advantageous manner.

In a particular embodiment of the invention, a stator of the electric motor comprises at least one

Linear guide device for guiding the spindle element along the adjustment. This achieves an advantageous guidance of the spindle element in the direction of the adjustment path and thus for releasing the tool clamp. For example, the linear guide device according to the invention is also known as

Holding unit or stop unit for holding / striking the spindle element, with respect to a rotation in the circumferential direction, formed. This means that advantageously prevents the linear guide rotation of the spindle element during operation in an advantageous manner, so that a relative movement between the spindle nut and spindle element by the

electromagnetic drive system of the electric motor in

advantageously leads to the rotation of the

Spindle nut a linear displacement / adjustment of the

Spindle element generated. Thus, a "co-rotation" of the spindle element in an advantageous manner by the

Linear guide device according to the invention prevents. This improves the reliability or the operation of the conversion unit.

Preferably, the linear guide device comprises an advantageous (planar) guide surface, which is aligned substantially parallel or longitudinal to the axis of rotation.

Optionally, this guide surface for guiding

Rolling, in particular rollers or the like can be used. Alternatively, a sliding guide can be realized as a linear guide. Essential here, as already mentioned, the striking or preventing a

"Mitdrehens" of the spindle element with the spindle nut according to the invention. This is essentially by the fixation or the striking of the spindle element by means of

Linear guide on the stator reached. In an advantageous variant of the invention, at least one limit switch and / or sensor for detecting a

End position of the spindle element and / or the spindle nut provided. For example, at least one proximity sensor, in particular inductively or capacitively or optically or magnetically, is provided. Alternatively, or in combination with this, a rotary encoder or incremental encoder or the like can be provided, which rotates or the

Adjustment travel / adjustment angle determined in the circumferential direction.

This makes it possible to indirectly determine the linear stroke or the axial adjustment path in the direction of the axis of rotation.

Especially a relative rotary encoder for relative determination of an adjustment in the circumferential direction can be combined with a limit switch or end position sensor in an advantageous manner. In contrast, can be dispensed with an end position detection, insofar as an absolute encoder is used, which is somewhat more complex.

As already mentioned, the release unit with the

Electric motor according to the invention are essentially combined with previously commercially available tool clamps or work together. This disc springs are often available for clamping the tool in the operating position. With the help of the electrical release unit according to the invention with

Linear adjustment or linear stroke of the spindle element, however, is also conceivable that the release unit can be used at the same time for clamping or clamping of the tool. This means that the release unit according to the invention with the electric motor, not only generates a release force or a release stroke in the direction tool along the axis of rotation, but possibly during operation also a clamping force against this direction, i. that by means of a pull rod or a tension element bracing of the tool in the tool holder or the like by corresponding stroke or linear adjustment to "back" or away from the tool side of the

Machine tool spindle can be generated. This would be the cost of the tool clamping or for a

Further reduce the machine tool spindle / motor spindle. In an advantageous variant of the invention is a

Sensor unit for detecting an electric motor parameter provided. For example, an evaluation of the

Power / power consumption and / or the operating current or operating voltage of the electric drive system provided. So can advantageously u.a. determining an idle and / or a release operation, and e.g. be evaluated as to whether / that the release unit operates the clamping system or the tool clamp and / or a pull rod or the like adjusted / dissolves and / or ob / that the clamping system or the

Tool clamp and / or the pull rod affected or

is / are not affected. Preferably, an actual-target comparison is provided, e.g. a low Leerlaufström or idle power and / or an electrical release current or a lifting / Löseleistung with a (stored) target power or the like is compared to a proper

Working or clamping the tool and / or the position or function of the clamping system and / or the tie rod to detect / determine.

EXEMPLARY EMBODIMENT An embodiment of the invention is shown in the drawing and we will explain it in more detail below with reference to the figures.

In detail shows:

Figure 1 schematically shows a first section through a

Release unit according to the invention and

Figure 2 schematically shows a second section through the

Release unit according to the invention.

In the figures, an electrical release unit 1 is shown, which has an electric motor 2 with a stator 3 and a rotor 4 includes. The stator 3 with electromagnetic coils 8 has circumferentially / externally on a stator 5, which forms a hollow cylindrical or annular cooling channel 7 for cooling water with a stator 6.

The rotor 4 comprises a rotor shaft 9, on the circumferential side permanent magnets 10 are fixed, esp. Glued and

bandaged. Is stored, the rotor shaft 9 with a ball bearing 11 and a tapered roller bearing 12, the latter can accommodate not only radial forces, but especially axial forces.

The inclusion of axial forces is therefore particularly important because "within" the hollow cylindrical rotor shaft 9, a linear drive 13 and a conversion unit 13th

is arranged. This is advantageously the

Rotation of the rotor 4 and the rotor shaft 9 in a

Linear displacement or translation in the axial direction or in the direction of the (concentric) axis of rotation 14 of the electric motor 2 implemented.

The linear drive 13 is designed as a ball screw 13, so that this includes numerous balls 15 as rolling elements 15. These are on the one hand between the rotor shaft 9, which also forms the spindle nut 9 of the linear drive 13, and a spindle member 16 and on the other hand between two plain bearings 17, 18 for supporting the spindle member 16, in addition to the balls 15, a radial support / leadership of the spindle element 16 can educate. An advantageous ball return for the axial return of the balls during operation is not shown in detail and is arranged in the interior of the rotor shaft 9 as a channel / formed.

With rotating / running electric motor 2 or rotating

Rotor shaft 9, the spindle member 19 is adjusted along the axis of rotation in the direction of a stroke H. For example, a thread pitch of about 5 mm is provided and a stroke H is about 8 to 20 mm long and presses with about 45kN, so that the electrical release unit 1 can replace a previously used hydraulic release unit, wherein a

Connecting flange 33 has corresponding fixing options or screw holes to be screwed / fixed at the rear end of a motor spindle or a tool clamp not shown.

To release such a tool clamp is a stop

19 is provided which actuates or releases a pull rod. In the figures, the spindle member 16 is in the non-actuating

Position or rest position shown, i. the

Spindle element 16 is "retracted." In this retracted rest position, a sensor 20 or limit switch 20 can

Detect rest position in an advantageous manner or capture. In the illustrated variant is in the hollow cylindrical

Spindle element 16 is a separate element 22, e.g. Magnet for a Hall sensor or the like, introduced, which is the sensor

20 can detect in an advantageous manner. Also, the sensor 20 may be formed as a proximity sensor 20, so that a groove 21 or recess together with the spindle member 16, the rest position in an advantageous manner for the sensor 20th

makes detectable. In addition, FIG. 1 schematically shows a second, separate element 23, with which the

Stop position or extended end position of the

Spindle element is detected. For the extended

End position, the sliding bearing element 18 in an advantageous manner a stop for abutment against the rotor shaft 9.

In addition, a (relative) rotary encoder 24 is provided which can detect the angular position of the rotor shaft 9. Here, a so-called. Encoder 25 and a ring gear 26 are provided, whereby the angular position can be detected.

Furthermore, for the linear drive 13 is preferably two

Linear guides 27 and torque supports 27 are provided. This supports the spindle element 16 in the circumferential direction on

Stator 3, wherein a rotation of the spindle member 16 is effectively prevented. This results in Rotating electric motor 2 and rotating rotor shaft 9, a relative movement between the rotor shaft 9 and spindle nut 9 and the spindle member 16, so that the spindle member 16 adjusted in an advantageous manner in the direction H and at

Reversing the direction of rotation of the electric motor 2 and the rotor shaft 9 back again (against the direction H). Thus, a release force in the direction H and, if necessary, a counterforce or clamping force against the direction H can be generated. The driving forces are advantageously over the balls 15 and with these corresponding

Threads 31, 32 of the rotor shaft 9 and the spindle element 16 transmitted.

The axial forces are advantageously over the

Stop 19 and the spindle element 16 and passed over the balls 15 mainly on the tapered roller bearing 12.

For advantageous storage or guidance, the

Linear guides 27 each have a fixing screw 28, on which a roller bearing 29 is mounted with outer ring and rollers as rolling elements. Hereby, the friction is reduced or minimized in the linear guiding of the spindle element 16 on a flat guide surface 30 of the stator 3. The spindle element 16 is hollow-cylindrical in order to transport or pass through a medium, in particular a cooling lubricant or the like, centrally in the interior.

LIST OF REFERENCE NUMBERS

1 release unit

2 electric motor

3 stators

4 rotor

5 housing

6 ring

7 cooling channel

8 coil

9 rotor shaft

10 permanent magnets

11 bearings

12 bearings

13 linear drive

14 axis of rotation

15 balls

16 spindle element

17 plain bearings

18 plain bearings

19 stop

20 sensor

21 groove

22 element

23 element

24 rotary encoders

25 encoders

26 sprocket

27 Linear guide 28 Screw

29 roller bearings

30 level

31 thread

32 thread 33 Connecting flange

Claims

claims

1. release unit (1) for a machine tool spindle, in particular motor spindle, for releasing a tool clamp, wherein the release unit (1) at least one along a

Adjusting path (H) comprises linearly adjustable adjusting element (16) for actuating the tool clamp, characterized

characterized in that the release unit (1) as a

electromagnetic drive system (8, 10) more comprehensive

Electric motor (2) with a about a rotational axis (14) rotating, hollow cylindrical rotor shaft (9) is formed, that the linearly adjustable adjusting element (16) as a spindle element (16) of a ümsetzungseinheit (13) for converting the rotation of the electric motor (2) in a linear adjustment (H)

is formed and that the rotor shaft (9) as to the

Rotary axis (14) rotating spindle nut (9) of

Implementing unit (13) is formed.

Second release unit according to claim 1, characterized in that the rotor shaft (9) of the electric motor (2) as a at least one permanent magnet (10) of the drive system comprehensive magnetic carrier element (9) is formed.

3. release unit according to one of the preceding claims, characterized in that the rotor shaft (9) of the electric motor (2) comprises at least one thread (31) of the conversion unit (13).

4. release unit according to one of the preceding claims, characterized in that rolling elements (15) between the

Spindle nut (9) and the spindle element (16) are arranged.

5. Release unit according to one of the preceding claims, characterized in that for the storage of the rotor shaft (9) in

Essentially the electromagnetic drive system (8, 10) of the electric motor (2) between a first bearing (11) and

at least one second bearing (12) is arranged.

6. Release unit according to one of the preceding claims, characterized in that at least one of the bearings (11, 12) is designed as a tapered roller bearing (12).

7. detachment unit according to one of the preceding claims, characterized in that for the storage of the spindle element (16), the rolling elements (15) between a first sliding bearing (17) and at least one second sliding bearing (18) are arranged.

8. release unit according to one of the preceding claims, characterized in that the rotor shaft (9) at least a first sliding surface of the first sliding bearing (17, 18) and / or a

Stator (3) of the electric motor (2) at least a second

Sliding surface of the second sliding bearing (17, 18).

9. release unit according to one of the preceding claims, characterized in that the first and / or second bearing (11, 12) of the rotor shaft (9) at least as a thrust bearing (12) of the

Spindle element (16) for receiving in the direction of

Is formed axis of rotation (14) aligned forces.

10. release unit according to one of the preceding claims, characterized in that a stator (3) of the electric motor (2) comprises at least one linear guide device (27) for guiding the spindle element (16) along the adjustment path (H).

11. Machine tool spindle, in particular motor spindle, with a release unit (1) for releasing a tool from a holding device for holding the tool in one

Processing phase, characterized in that the

Release unit (1) according to one of the preceding claims

is trained.