PRESSING DEVICE

Description

TECHNICAL AREA

[0001] The present invention relates to a pressing device according to the preamble of claim 1, as is known, for example, from WO2022 / 112021A1. STATE OF THE ART

[0002] Press fittings are frequently used to connect drinking water pipes, and these are crimped using a crimping tool. Such crimping tools comprise a crimping device and a crimping tool, such as a crimping jaw or crimping loop, which is interchangeably attached to the crimping device. The crimping device applies crimping force to the crimping jaws, which then crimp the fitting. During the crimping process, a piston in the crimping device extends with high force and acts on the crimping jaws.

[0003] For example, DE 20 305 473 U1 discloses a press device of this type. The movement from the drive motor is converted by means of a planetary gear. Although a planetary gear has a very good efficiency, its complex mechanical structure is very prone to failure. In addition, such planetary gears usually have a comparatively high weight, which is a disadvantage for hand-operated press devices. PRESENTATION OF THE INVENTION

[0004] Based on this prior art, the present invention aims to provide a pressing device that overcomes the disadvantages of the prior art. In particular, it is an object of the present invention to provide a pressing device that is less prone to malfunctions.

[0005] A press device according to claim 1 solves these and other problems. Accordingly, a press device comprises a drive motor with a drive shaft, a gearbox driven by the drive shaft, a spindle drive driven by the gearbox with a spindle defining a central axis and a spindle nut, a press piston driven by the spindle drive, and a tool holder for receiving a press tool. The gearbox is a cycloidal gearbox with an output section, wherein the output section is operatively connected to the spindle drive via a spindle-drive-side engagement section such that the output section drives the spindle drive.

[0006] The use of a cycloidal gearbox is advantageous because a cycloidal gearbox can be manufactured from very few components, which increases its service life. Furthermore, this increases operational reliability and availability.

[0007] Another advantage is that the press tool can be provided in a very compact manner through the use of a cycloidal gearbox. In particular, large speed reductions can be achieved with a small installation space.

[0008] Cycloidal gearboxes also offer the advantage that the individual gearbox elements can perform rolling movements relative to each other, which results in very low wear, especially under high forces. Compared to other gearboxes, such as planetary gearboxes, cycloidal gearboxes generally produce less noise. Another advantage is that high torques can be transmitted in a relatively compact installation space.

[0009] The drive motor is preferably an electric motor. Other types of drive motors, such as hydraulic drive motors, are also conceivable.

[0010] The press piston is moved from a starting position to a pressing position by the spindle drive. During this movement, the press piston pushes into the tool holder. The pressing tool, located in the tool holder, is actuated accordingly during this movement. When the press piston reaches the pressing position, the pressing operation performed by the pressing tool has been completed.

[0011] In a first embodiment, the output section of the cycloidal gear acts on the spindle nut. The spindle, which is driven by the spindle nut, acts on the press piston.

[0012] Preferably, the cycloidal gear, the drive shaft, and the drive motor are designed such that an interior space is created, wherein the spindle extends out of this interior space in its initial position and is moved out of the interior space when the drive motor is actuated. In other words, the spindle projects from the tool holder into the interior space.

[0013] This allows the overall length of the pressing device to be reduced, which has the advantage that the pressing device can also be used in confined spaces.

[0014] The interior space is provided primarily by an opening extending through the drive shaft. The drive motor and parts of the cycloidal gear are located on the outside of the drive shaft. Viewed from the side of the spindle nut, the opening extends completely through the entire length of the drive shaft. Viewed from the side of the spindle nut, the spindle extends essentially completely through the opening.

[0015] Preferably, the spindle nut has a spindle-drive-side engagement section. The output section engages with the spindle-drive-side engagement section in such a way that a rotary motion can be transmitted from the output section to the spindle nut.

[0016] Preferably, the engagement section on the spindle drive side is arranged on the outside of the spindle nut.

[0017] Preferably, the spindle nut extends from the output section towards the tool holder and has at least one axial bearing point and / or one radial bearing point.

[0018] The axial bearing point is formed, for example, by a flange extending radially outwards from the spindle nut. The radial bearing point is preferably provided by the outer surface of the spindle nut at the front end, that is, at the end opposite the engagement section. The bearing points are supported against a housing by bearings such as rolling or sliding bearings.

[0019] Preferably, the spindle is mounted in a fixed but axially displaceable manner with respect to rotation about the central axis, such that the spindle is axially movable when the spindle nut is rotated.

[0020] Preferably, the spindle acts on the press piston with a front spindle end.

[0021] In a second embodiment, the output section of the cycloidal gear acts on the spindle and the spindle nut acts on the press piston.

[0022] Preferably, the drive motor is arranged behind the end of the spindle, viewed from the tool holder. While this increases the length of the press compared to the first embodiment, the diameter of the press can be made smaller in this second embodiment.

[0023] Preferably, the spindle has the spindle-drive side engagement section and the output section engages with the spindle-drive side engagement section in such a way that a rotary movement can be transmitted from the output section to the spindle.

[0024] Preferably, the engagement section on the spindle drive side is arranged on the outside of the spindle.

[0025] Preferably, the spindle extends from the output section towards the tool holder.

[0026] Preferably, the spindle has at least one axial bearing point and / or one radial bearing point. The axial bearing point is formed, for example, by a flange extending radially outwards from the spindle. The bearing points are supported against a housing by bearings such as rolling or sliding bearings.

[0027] Preferably, the spindle nut is mounted in a fixed but axially displaceable manner with respect to rotation about the central axis, such that the spindle nut is axially movable when the spindle is rotated.

[0028] Preferably, the spindle nut acts on the press piston with a front spindle end.

[0029] According to the invention, the cycloidal gear comprises a rolling ring with an inner rolling structure providing the output section and an outer rolling structure, as well as a further rolling structure fixed to the rolling ring. The rolling ring is mounted on a bearing section on the drive shaft. The bearing section is arranged eccentrically to a drive section of the drive shaft driven by the drive motor. In other words, the bearing section extends in a circular cylindrical shape around an eccentric axis, and the drive section extends around a central axis. The eccentric axis runs parallel to and laterally offset from the central axis. Therefore, the eccentric axis is not collinear with the central axis. The bearing section is thus eccentric to the drive shaft. The central axis of the drive section is preferably collinear with the central axis of the spindle or the spindle nut.

[0030] The outer rolling structure is eccentric to the inner rolling structure and engages with it, whereby, when the drive shaft rotates, the outer rolling structure performs a rolling motion within the inner rolling structure. The inner rolling structure surrounds the outer rolling structure, allowing the rolling ring to move eccentrically to the outer rolling structure.

[0031] The central axis of the further rolling structure is preferably collinear with the central axis of the drive section and collinear with the central axis of the spindle or the spindle nut.

[0032] The inner rolling structure is located eccentrically to the spindle-side engagement section and engages with it. During the execution of the aforementioned rolling motion, the inner rolling structure drives the spindle-side engagement section with a rotary motion. The inner rolling structure surrounds the spindle-side engagement section. The spindle-side engagement section preferably also has a rolling structure that engages with the inner rolling structure.

[0033] Preferably, the outer rolling structure and the inner rolling structure are provided by convexly rounded rolling teeth and concavely rounded rolling gaps, each located between two rolling teeth. At least one rolling tooth of the outer rolling structure engages in at least one rolling gap of the inner rolling structure in a rotationally transmitting manner.

[0034] The term "rotational motion transmission" means that a rotational motion can be transmitted between the rolling tooth and the rolling gap. This means that at that moment, the rolling tooth is in full-surface contact with the rolling gap. With adjacent pairs of rolling teeth and rolling gaps, the rolling teeth do protrude into the rolling gap, but are not in direct, full-surface rolling contact; rather, they are either just before or have already passed through this contact. This partial rolling contact can, for example, be linear.

[0035] Preferably, the inner rolling structure and the spindle-side engagement section are provided by convexly rounded rolling teeth and concavely rounded rolling gaps, each located between two rolling teeth. At least one rolling tooth of the inner rolling structure engages in at least one rolling gap of the spindle-side engagement section, transmitting rotary motion.

[0036] The aforementioned rolling teeth and rolling gaps are arranged alternately with each other and extend alternately completely around the circumference of the central axis.

[0037] Preferably, the rolling ring is pivotably mounted on the bearing section relative to the bearing section, in particular that a bearing, especially a rolling bearing such as a ball bearing or a sliding bearing, is arranged between the rolling ring and the bearing section.

[0038] Preferably, the cycloidal gear provides a reduction between the drive motor and the spindle gear, wherein the reduction ratio of the cycloidal gear is between 25:1 and 60:1, particularly 30:1.

[0039] In all embodiments, the spindle has an external thread. The spindle nut has an internal thread in all embodiments. The two threads mesh. Preferably, the gear components are made of a heat-treated steel, such as 42CrMoA or Cf53. The housing components and the tool holder are preferably made of high-strength aluminum, such as EN AW 7075.

[0040] Further embodiments are specified in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Preferred embodiments of the invention are described below with reference to the drawings, which serve only for illustration and are not to be interpreted restrictively. The drawings show: Fig. 1 a sectional view of a press device according to a first embodiment, Fig. 2 a detailed view of the Figure 1 ; Fig. 3a a partially cutaway perspective view of the press device according to Figure 1 in the initial position; Fig. 3 legs partially cutaway perspective view of the press device after Figure 1 in the pressing position; Fig. 4 a further sectional view of the pressing device according to Figure 1 ; Fig. 5a a sectional view along the section line AA according to the Figure 4 ; Fig. 5a a sectional view along the section line BB according to the Figure 4 Fig. 6a a perspective exploded view of the press according to the preceding figures; Fig. 6b a perspective view of the press according to Figure 6a Fig. 7 a sectional view of a press device according to a first embodiment, Fig. 8 a detailed view of the Figure 7 ; Fig. 9a a partially cutaway perspective view of the press device according to Figure 7 in the initial position; Fig. 9 legs partially cutaway perspective view of the press device after Figure 7in the pressing position; Fig. 10 a further sectional view of the pressing device according to Figure 7 ; Fig. 11a a sectional view along the section line AA according to the Figure 10 ; Fig. 11 sectional view along the section line BB according to the Figure 10 ; Fig. 12a a perspective exploded view of the press according to the preceding Figures 7 to 11b ; and Fig. 12 leg perspective view of the press device according to Figure 12a . DESCRIPTION OF PREFERRED EXECUTION FORMS

[0042] In the Figures 1 to 6b A first embodiment of a pressing device 1 according to the invention is shown and described in the Figures 7 to 12b A second embodiment of a pressing device 1 according to the invention is shown. Identical parts or elements bear the same reference numerals.

[0043] The pressing device 1 according to the present invention comprises a drive motor 2 with a drive shaft 3, a gearbox 4 driven by the drive shaft 3, a spindle drive 5 driven by the gearbox 4 with a spindle 6 defining a central axis M and a spindle nut 7, a pressing piston 8 driven by the spindle drive 5, and a tool holder 9 for receiving a pressing tool. The pressing tool, which is not shown in the figures, is typically a pressing pliers with pressing jaws or a pressing loop.

[0044] The drive motor 2 is preferably an electric motor 2. The electric motor 2 further comprises a control unit arranged on a circuit board 23. The circuit board 23 is arranged at the end face of the drive motor 2 on the side opposite the spindle 6. The drive motor can also be a different type of motor, such as a hydraulic motor.

[0045] In both embodiments, the drive motor 2 partially surrounds the drive shaft 3 on its outer surface. The drive motor 2 acts on a drive section 34 on the drive shaft 3. The drive section 34 extends around a central axis M3. The central axis M3 is collinear with the central axis M of the spindle 6. The drive shaft 3 extends at least partially, and in this case completely, through the drive motor 2.

[0046] The drive shaft 3 projects from the drive motor 2 on the side facing the spindle. The drive shaft 3 has an optional cylindrical opening 24 at this point, which extends into the drive shaft 3 along the central axis M, viewed from the side of the spindle 6. The opening 24 preferably extends completely through the drive shaft 3. The drive shaft 3 engages with the gearbox 4 at its front end 25. This engagement is explained in more detail below.

[0047] According to the invention, the transmission 4 is designed as a cycloidal transmission. The cycloidal transmission 4 acts on the spindle transmission 5. The rotary motion provided by the drive motor 2 is reduced by the cycloidal transmission 4. The cycloidal transmission 4 has an output section 10 which is connected to the spindle transmission 5 via a spindle-side engagement section 11 such that the output section 10 of the cycloidal transmission drives the spindle transmission 5.

[0048] The spindle 6 has an external thread 26 and the spindle nut 7 has an internal thread 27. The external thread 26 and the internal thread 27 are in mesh with each other.

[0049] In the first embodiment, the output section 10 of the cycloidal gear 4 acts on the spindle nut 7. The spindle 6 acts on the press piston 8. The spindle nut 7 has the spindle-side engagement section 11. The spindle-side engagement section 11 is an integral part of the spindle nut 7; in particular, the spindle-side engagement section 11 is arranged on the spindle nut 7, especially by grinding or milling. Alternatively, the spindle-side engagement section 11 can also be formed on a separate element that is rigidly connected to the spindle nut 7.

[0050] In the first embodiment, the spindle nut 7 is mounted axially fixed and rotatable about the central axis M. The spindle 6 is mounted rigidly with respect to rotation about the central axis M but axially displaceable, such that the spindle 6 is axially movable when the spindle nut 7 rotates. In the illustrated embodiment, the spindle nut 7 has a flange 28 which extends radially away from the spindle nut 7. The flange 28 serves to support the spindle nut 7 in the direction of the central axis M. An axial bearing 29 is arranged here for supporting the spindle nut 7. A radial bearing 14 is arranged at the front for supporting the spindle nut 7.

[0051] In the first embodiment, the spindle 6 acts on the press piston 8 and, during its movement, pushes it from its initial position, as in the Figure 3a shown, in the pressing position, as in the Figure 3bshown facing forward into the tool holder 9. The press piston 8 acts on the tool. In the illustrated embodiment, the press piston 8 has press rollers 30 for this purpose.

[0052] In the first embodiment, the cycloidal gear 4, the drive shaft 3, and the drive motor 2 are designed such that an interior space 12 is created, wherein the spindle 6 extends out of the interior space 12 in its initial position and wherein the spindle 6 is moved out of the interior space 12 when the drive motor 2 is actuated. In the embodiment shown, the interior space 12 is essentially provided by the opening 24 described above. The spindle 6 extends out of the interior space 12 in its initial position, as shown in the Figure 3a and 4 shown, in the direction of the central axis M essentially completely through the entire length of the opening 24.

[0053] Based on the Figures 4 to 6aThe construction of the cycloidal gear according to the first embodiment will now be explained in more detail. Figure 5a shows a cross-section through the engagement of the cycloidal gear 4 and the spindle nut 7. Figure 5b shows a section through the engagement of the cycloidal gear 4 and the drive shaft 3 of the drive motor 2.

[0054] The cycloidal gear 4 has a rolling ring 15 and a further rolling structure 18. The rolling ring 15 has an inner rolling structure 16 providing the output section 10 and an outer rolling structure 17. The further rolling structure 18 is fixedly arranged relative to the rolling ring 15.

[0055] The rolling ring 15 is mounted on a bearing section 19 on the drive shaft 3. The bearing section 19 extends around an eccentric axis E, which runs parallel to and laterally offset from the central axis M3 of the drive section 34 of the drive shaft 3. The rolling ring 15 is mounted on the bearing section 19 via a bearing 22. This eccentricity is described in the Figure 5b As shown. Due to the eccentricity, the outer rolling structure 17 is eccentric to the further rolling structure 18. The outer rolling structure 17 and the further rolling structure 18 are in mesh with each other. When the drive shaft 3 rotates, the outer rolling structure 17 performs a rolling motion within the further rolling structure 18. The rolling ring 15 rolls from its position in the Figure 5b relative to the fixed further rolling structure 18. That is, the contact point between the outer rolling structure 17 and the further rolling structure 18 shifts by the circumference of the further rolling structure 18.

[0056] Furthermore, the inner rolling structure 16 is located eccentrically to the spindle-drive-side engagement section 11, which in the Figure 5a As can be seen, the inner rolling structure 16 engages with the spindle-side engagement section 11. During the execution of the aforementioned rolling motion, the inner rolling structure 16 drives the spindle-side engagement section 11 with a rotary motion. The spindle-side engagement section 11 also has a rolling structure, so that a rolling motion is also provided between the inner rolling structure 16 and the spindle-side engagement section 11.

[0057] The further rolling structure 18 is preferably firmly mounted in a housing 35.

[0058] The outer rolling structure 17 and the further rolling structure 18 are provided by convexly rounded rolling teeth 20 and concavely rounded rolling gaps 21, each located between two rolling teeth 20. At least one rolling tooth 20 of the outer rolling structure 17 engages in at least one rolling gap 21 of the inner rolling structure 16, transmitting a rotational motion.

[0059] The inner rolling structure 16 and the spindle-side engagement section 11 are provided by convexly rounded rolling teeth 21 and concavely rounded rolling gaps 21, each located between two rolling teeth 21. At least one rolling tooth 21 of the inner rolling structure 16 engages in at least one rolling gap 22 of the spindle-side engagement section 11, transmitting rotary motion.

[0060] In the second embodiment, the output section 10 of the cycloidal gear 4 acts on the spindle 6. The spindle nut 7 acts on the press piston 8. The spindle 6 has the spindle-gear engagement section 11. The spindle-gear engagement section 11 is an integral part of the spindle 6; in particular, the spindle-gear engagement section 11 is ground flush with the spindle 6. Alternatively, the spindle-gear engagement section 11 can also be formed on a separate element that is rigidly connected to the spindle 6. The drive motor 2 is arranged behind the end of the spindle 6, viewed from the tool holder 9. The cycloidal gear 2 is located between the drive motor 2 and the spindle 6. The spindle 6 extends from the output section 10 towards the tool holder 9. The spindle 6 has at least one axial bearing 14 and / or at least one radial bearing 15.The axial bearing point is formed, for example, by a flange 33 extending radially away from the outside of the spindle.

[0061] The spindle 6 has the spindle-drive-side engagement section 11, and the output section 10 engages with the spindle-drive-side engagement section 11 in such a way that a rotary motion can be transmitted from the output section 10 to the spindle 6. The spindle nut 7 is radially fixed and axially displaceable, such that the spindle nut is axially movable when the spindle rotates. Here, the spindle nut 7 has a T-nut 31 on its outer side, which is axially movable in a groove 32, which is part of a housing.

[0062] Based on the Figures 8 to 12a The construction of the cycloidal gear according to the second embodiment will now be explained in more detail. Figure 11a shows a cross-section through the engagement of the cycloidal gear 4 and the spindle nut 7. Figure 11bshows a section through the engagement of the cycloidal gear 4 and the drive shaft 3 of the drive motor 2.

[0063] The cycloidal gear 4 has a rolling ring 15 and a further rolling structure 18. The rolling ring 15 has an inner rolling structure 16 providing the output section 10 and an outer rolling structure 17. The further rolling structure 18 is fixedly arranged relative to the rolling ring 15.

[0064] The rolling ring 15 is mounted on a bearing section 19 on the drive shaft 3. The bearing section 19 extends around an eccentric axis E, which runs parallel to and laterally offset from the central axis M3 of the drive section 34 of the drive shaft 3. The rolling ring 15 is mounted on the bearing section 19 via a bearing 22. This eccentricity is described in the Figure 11bAs shown. Due to the eccentricity, the outer rolling structure 17 is eccentric to the further rolling structure 18. The outer rolling structure 17 and the further rolling structure 18 are in mesh with each other. When the drive shaft 3 rotates, the outer rolling structure 17 performs a rolling motion within the further rolling structure 18. The rolling ring 15 rolls from its position in the Figure 5b relative to the fixed further rolling structure 18. That is, the contact point between the outer rolling structure 17 and the further rolling structure 18 shifts by the circumference of the further rolling structure 18.

[0065] Furthermore, the inner rolling structure 16 is located eccentrically to the spindle-drive-side engagement section 11, which in the Figure 11aAs can be seen, the inner rolling structure 16 engages with the spindle-side engagement section 11. During the execution of the aforementioned rolling motion, the inner rolling structure 16 drives the spindle-side engagement section 11 with a rotary motion. The spindle-side engagement section 11 also has a rolling structure, so that a rolling motion is also provided between the inner rolling structure 16 and the spindle-side engagement section 11.

[0066] The further rolling structure 18 is preferably firmly mounted in a housing 35.

[0067] The outer rolling structure 17 and the further rolling structure 18 are provided by convexly rounded rolling teeth 20 and concavely rounded rolling gaps 21, each located between two rolling teeth 20. At least one rolling tooth 20 of the outer rolling structure 17 engages in at least one rolling gap 21 of the inner rolling structure 16, transmitting a rotational motion.

[0068] The inner rolling structure 16 and the spindle-side engagement section 11 are provided by convexly rounded rolling teeth 21 and concavely rounded rolling gaps 21, each located between two rolling teeth 21. At least one rolling tooth 21 of the inner rolling structure 16 engages in at least one rolling gap 22 of the spindle-side engagement section 11, transmitting rotary motion. REFERENCE MARK LIST

[0069] 1 Pressing device 21 Rolling gap 2 drive motor 22 Storage 3 drive shaft 23 circuit board 4 Gearbox, cycloidal gearbox 24 opening 5 Spindle gear 26 external thread 6 spindle 27 internal thread 7 Spindle nut 28 flange 8 Press piston 29 Axial bearing 9 Tool holder 30 Press rollers 10 Drive section 31 T-nut 11 spindle-side engagement section 32 groove 33 Flange (spindle) 12 interior 34 drive section 13 Axial bearing 35 Housing 14 radial bearing point 15 rolling ring 16 internal rolling structure E Eccentric axis 17 outer rolling structure M Central axis spindle 18 further rolling structure M3 Center axle drive section 19 Storage section 20 rolling tooth

Claims

1. Pressing device (1) comprising a drive motor (2) with a drive shaft (3), a gearbox (4) driven by the drive shaft (3), a spindle gear (5) driven by the gearbox (4) with a spindle (6) defining a central axis (M) and a spindle nut (7), a pressing piston (8) driven by the spindle gear (5), and a tool holder (9) for holding a pressing tool, wherein the gearbox (4) is a cycloidal gear with an output section (10), wherein the output section (10) is operatively connected to the spindle gear (5) via an engagement section (11) on the spindle gear side in such a way that the output section (10) drives the spindle gear (5), characterised in that the cycloidal gear (4) has a rolling ring (15) with an inner rolling structure (16) providing the output section (10) and with an outer rolling structure (17), and a further rolling structure (18) which is arranged in a fixed manner relative to the rolling ring (15), wherein the rolling ring (15) is mounted on a bearing section (19) on the drive shaft (3), which bearing section (19) is arranged eccentrically to a drive section (34) of the drive shaft (3) driven by the drive motor (2), wherein the outer rolling structure (17) is eccentric to the further rolling structure (18) and engages with the latter, wherein, upon rotation of the drive shaft (3), the outer rolling structure (17) performs a rolling movement in the further rolling structure (18), and wherein the inner rolling structure (16) is eccentric to the spindle drive-side engagement section (11) and engages with it, wherein, when the said rolling movement is performed, the inner rolling structure (16) drives the spindle drive-side engagement section (11) with a rotary movement.

2. Pressing device (1) according to claim 1, characterised in that the output section (10) of the cycloidal gear (4) acts on the spindle nut (7) and that the spindle (6) acts on the pressing piston (8).

3. Pressing device (1) according to claim 2, characterised in that the cycloidal gear (4), the drive shaft (3) and the drive motor (2) are designed in such a way that an interior space (12) is created, whereby the spindle (6) extends out of the interior space (12) in its initial position and whereby the spindle (6) is moved out of the interior space (12) when the drive motor (2) is activated.

4. Pressing device (1) according to claim 2 or 3, characterised in that the spindle nut (7) has the spindle drive-side engagement section (11) and that the output section (10) engages with the spindle drive-side engagement section (11) in such a way that a rotary movement can be transmitted from the output section (10) to the spindle nut (7).

5. Pressing device (1) according to one of the preceding claims 2 to 4, characterised in that the spindle nut (7) extends in the direction of the tool holder (9) as seen from the output section (10) and has at least one axial bearing point (13) and / or one radial bearing point (14).

6. Pressing device (1) according to one of the preceding claims 2 to 5, characterised in that the spindle (6) is mounted so that it is fixed with respect to rotation about the central axis (M) but can be displaced axially, such that the spindle (6) can be moved axially when the spindle nut (7) is rotated.

7. Pressing device (1) according to claim 1, characterised in that the output section (10) of the cycloidal gear (4) acts on the spindle (6) and that the spindle nut (7) acts on the pressing piston (8).

8. Pressing device (1) according to claim 7, characterised in that the drive motor (2) is arranged behind the end of the spindle (6) as seen from the tool holder (9).

9. Pressing device according to claim 7 or 8, characterised in that the spindle (6) has the spindle drive-side engagement section (11) and that the output section (10) engages with the spindle drive-side engagement section (11) in such a way that a rotary movement can be transmitted from the output section (10) to the spindle (6).

10. Pressing device (1) according to one of the preceding claims 7 to 9, characterised in that the spindle (6) extends in the direction of the tool holder (9) as seen from the output section (10) and / or has at least one axial bearing point (14) and / or one radial bearing point (15).

11. Pressing device (1) according to one of the preceding claims 7 to 10, characterised in that the spindle nut (7) is mounted so that it is fixed with respect to rotation about the central axis (M) but can be displaced axially, such that the spindle nut can be moved axially when the spindle is rotated.

12. Pressing device (1) according to one of the preceding claims, characterised in that the outer rolling structure (17) and the further rolling structure (18) are provided by convexly rounded rolling teeth (20) and concavely rounded rolling gaps (21) which are located between two rolling teeth (20), at least one rolling tooth (20) of the outer rolling structure (17) engaging in at least one rolling gap (21) of the inner rolling structure (16) in a manner that transmits rotational movement.

13. Pressing device (1) according to one of the preceding claims, characterised in that the inner rolling structure (16) and the spindle drive-side engagement section (11) are provided with convexly rounded rolling teeth (21) and concavely rounded rolling gaps (21) which are located between two rolling teeth (21), wherein at least one rolling tooth (21) of the inner rolling structure (16) engages in at least one rolling gap (22) of the spindle drive side engagement section (11) in a manner that transmits rotational movement.

14. Pressing device (1) according to one of the preceding claims, characterised in that the rolling ring (15) is mounted on the bearing section (19) so as to be pivotable relative to the bearing section (19), in particular in that a bearing (22), in particular a rolling bearing such as a ball bearing, or a plain bearing is arranged between the rolling ring (15) and the bearing section.

15. Pressing device (1) according to one of the preceding claims, characterised in that the cycloidal gear (4) provides a reduction between the drive motor (2) and the spindle gear (5), wherein the reduction ratio of the cycloidal gear is between 25:1 and 60:1, in particular 30:1.