ELECTROMECHANICAL SPINDLE DRIVE

Abstract

An electromechanical spindle drive includes a housing, a motor, a rotational part in the form of a spindle nut, the rotational part being rotated by the motor about a rotational axis, a spindle which interacts with the rotational part, the threaded section of which is arranged within the rotational part and which exits the rotational part at a spindle outlet end, and bearings by means of which the rotational part is rotatably mounted relative to the housing, wherein at least one, preferably at least two of the bearings, are arranged in the region of the spindle outlet end of the rotational part and/or are designed in the form of a radial bearing.

Claims

1. An electromechanical spindle drive (1) comprising a housing (13), a motor (2), a rotational part (3) in the form of a spindle nut, said rotational part (3) being rotatable by the motor (2) about a rotational axis (4), a spindle (23) which interacts with the rotational part (3), the threaded section of which is arranged within the rotational part (3) and which exits the rotational part (3) at a spindle outlet end (35), and bearings (37, 38, 39) by means of which the rotational part (3) is rotatably mounted relative to the housing (13), wherein at least one, preferably at least two of the bearings (37), are arranged in the region of the spindle outlet end (35) of the rotational part (3) and/or are designed in the form of a radial bearing.

2. The electromechanical spindle drive according to claim 1, wherein the at least one bearing (37) arranged in the region of the spindle outlet end (35) of the rotational part (3) is arranged inside the rotational part (3), preferably on an inner side of the rotational part (3).

3. The electromechanical spindle drive according to claim 1, wherein the at least one bearing (37) arranged in the region of the spindle outlet end (35) of the rotational part (3) is arranged between the inside of the rotational part (3) and a bearing seat (36) projecting into the interior of the rotational part (3), wherein preferably the bearing seat (36) is formed on a housing part (13c), preferably an end-face housing cover, of the housing (13).

4. The electromechanical spindle drive according to claim 1, wherein the at least one bearing (37) arranged in the region of the spindle outlet end (35) of the rotational part (3) is arranged axially overlapping with the stator (2a) and/or the rotor (2b) of the motor (2) and/or is arranged within an area enclosed by the stator (2a) and/or rotor (2b) of the motor (2).

5. The electromechanical spindle drive according to claim 1, wherein the at least one bearing (37) arranged in the region of the spindle outlet end (35) of the rotational part (3) is a rolling bearing, in particular a ball bearing.

6. The electromechanical spindle drive according to claim 1, wherein at least one of the bearings (39), preferably a radial bearing, is arranged in the area of the end of the rotational part (3) opposite the spindle outlet end (35).

7. The electromechanical spindle drive according to claim 1, wherein at least one of the bearings (38) is an axial bearing, which is preferably arranged in the area between the motor (2) and a braking device (5) of the electromechanical spindle drive (1).

8. The electromechanical spindle drive according to claim 1, wherein the stator (2a) of the motor (2) surrounds the rotational part (3) and/or that wherein the rotor (2b) of the motor (2) comprises pole elements, preferably in the form of permanent magnets, mounted on the outside of the rotational part (3), preferably in a removable manner, and/or that wherein the motor (2) is a synchronous motor.

9. The electromechanical spindle drive according to claim 1, wherein the spindle drive (1) is a rolling spindle drive in which rolling elements (45), in particular in the form of balls, are guided in a circulating path, a first portion of the circulating path being formed between the internal thread of the rotational part (3) and the external thread of the spindle (23) and a second portion being formed by a return channel (44), the return channel (44) being formed in the interior of the spindle (23).

10. The electromechanical spindle drive according claim 1, wherein at the end of the rotational part (3) opposite the spindle outlet end (35), an attachment part (40) is connected to the rotational part (3), preferably the attachment part (40) having a portion located inside the rotational part (3) and/or forming a stop for the spindle (23).

11. The electromechanical spindle drive according to claim 10, wherein a portion (46) of the attachment part (40) located outside the rotational part (3) is formed in the shape of a pin, wherein the longitudinal axis of the pin-shaped portion (46) coincides with the rotational axis (4) of the rotational part (3), wherein preferably the maximum diameter of the portion of the attachment part (40) located inside the rotational part (3) is at least 3 times, preferably at least 4 times, as large as the diameter of the pin-shaped section (46)

12. The electromechanical spindle drive according to claim 10, wherein the spindle drive (1) comprises a sensor device (47), wherein a portion (46) of the attachment part (40) located outside the rotation part (3) is disposed in the detection range of the sensor device (47), wherein preferably the sensor device (47) is a rotary encoder which detects the rotation of the attachment part (40).

13. The electromechanical spindle drive according to claim 10, wherein a lubricant channel (41) is configured in the attachment part (40) for supplying lubricant to the interior of the rotational part (3).

14. The electromechanical spindle drive according to claim 13, wherein the path of a first portion (42) of the lubricant channel (41) is aligned with the rotational axis (4) of the rotational part (3), preferably the first portion (42) of the lubricant channel (41) running in a portion (46) of the attachment part (40) located outside the rotational part (3).

15. The electromechanical spindle drive according to claim 13, wherein the path of a second portion (43) of the lubricant channel (41) has a radial component with respect to the rotational axis (4) and/or is oblique to the rotational axis (4), wherein preferably the second portion (43) of the lubricant channel (41) runs in a portion of the attachment part (40) located inside the rotational part (3) and/or ends at an exit point (48), which, with respect to the rotational axis (4), is arranged in a peripheral region of the attachment part (40).

16. The electromechanical spindle drive according to any claim 10, wherein the attachment part (40) is surrounded by a braking device (5) of the spindle drive (1), wherein preferably the attachment part (40) is disposed within a central recess of a brake disc (6) of the braking device (5) and/or forms a preferably positive receptacle for a brake disc (6) of the braking device (5).

17. The electromechanical spindle drive according to claim 1, wherein cooling fins (49) are arranged on the outside of the housing (13), at least in the area of the motor (2), wherein the cooling fins (49) are preferably removable from the housing body.

18. The electromechanical spindle drive according to claim 1, wherein the spindle drive (1) has a modular design.

19. The electromechanical spindle drive according to claim 1, wherein the spindle drive (1) has a braking device (5) which can be actuated between a braking position and a released position, wherein the braking device (5) acts on the rotational part (3), wherein preferably the braking device (5) is arranged in the region of the end of the rotational part (3) opposite the spindle outlet end (35).

20. The electromechanical spindle drive according to claim 1, wherein the braking device (5) has a brake disc (6) that rotates with the rotational part (3) and a braking element (7) that can be adjusted in the axial direction and acts on the brake disc (6) in the braking position.

21. The electromechanical spindle drive according to claim 1, wherein the brake disc (6) has an inner area (8), a friction surface area (10) extending annularly around the rotational axis (4) with a first friction surface (11) formed on a first side of the brake disc (6), and an intermediate area (9) extending between the friction surface area (10) and the inner area (8) around the rotational axis (4), and wherein a first mating surface (17) is formed on the braking element (7), which mating surface faces the first friction surface (11) and interacts with the first friction surface (11) in the braking position.

22. The electromechanical spindle drive according to claim 21, wherein the intermediate region (9) of the brake disc (6), both in the released position and in the braking position, is free of contact with the braking element (7) and/or wherein in the braking position the contact of the braking element (7) with the brake disc (6) is limited to the first friction surface (11).

23. The electromechanical spindle drive according to claim 21, wherein the intermediate region (9) is a deformation area which is elastically deformable in the axial direction by the action of the brake element (7) on the brake disc (6), wherein preferably cut-outs (19), preferably in the form of perforations, and/or material weakenings are formed in the deformation area.

24. The electromechanical spindle drive according to claim 21, wherein the friction surface area (10) comprises a second friction surface (12) formed on the second side of the brake disc (6) opposite to the first side, and in that wherein the friction surface area (10) of the brake disc (6) is arranged between the first mating surface (17) and a second mating surface (18) facing the second friction surface (12) and cooperating with the second friction surface (12) in the braking position.

25. A spindle drive component set comprising components for a plurality of electromechanical spindle drives (1) according to claim 1, wherein the component set having components of different types and the components having connection interfaces for connecting the components to one another, and wherein components of the same type have different sizes, wherein the connection interfaces of differently sized components of the same type are of the same dimensions.

26. The spindle drive component set according to claim 25, wherein the component set has first housing parts of different length and/or width, and second housing parts of different length and/or width, wherein the connection interfaces of the first housing parts for connection to the second housing parts have the same dimensions for all first housing parts and for all second housing parts.

27. The spindle drive component set according to claim 25, wherein the component set has rotational parts of different length and/or width, and housing parts of different length and/or width and/or motors of different length and/or width, wherein the connection interfaces of the rotational parts for connection to the housing parts and/or motors have the same dimensions for all rotational parts, and/or wherein the connection interfaces of the housing parts and/or motors for connection to the rotational parts have the same dimensions for all housing parts and/or motors.

28. A forming machine (20), in particular a bending machine, for forming a preferably plate-type workpiece (27), wherein the forming machine (20) comprises at least one electromechanical drive (1), at least one forming tool (28) whose working movement is effected by the electromechanical drive (1), wherein the electromechanical drive (1) is a spindle drive according to claim 1.

29. A method for forming a preferably plate-type workpiece (27) with a forming machine (20), in particular a bending machine, wherein the forming machine (20) is a forming machine according to claim 28 and that the motor (2) of the electromechanical spindle drive (1) for forming the workpiece (27) is controlled by a control device (30).

Description

[0118] These show respectively in a very simplified schematic representation:

[0119] FIG. 1 an electromechanical drive in a cut view;

[0120] FIG. 2 a portion of a braking device with a perspective view;

[0121] FIG. 3 a braking device in a cut view;

[0122] FIG. 4 a brake disc;

[0123] FIG. 5 the interaction of the braking element and the brake disc;

[0124] FIG. 6 a braking device in the released position;

[0125] FIG. 7 a braking device in the released position;

[0126] FIG. 8 a braking device with a second braking and mating surface in released position;

[0127] FIG. 9 a braking device with a second braking and mating surface in released position;

[0128] FIG. 10 a braking device with a preloaded braking element;

[0129] FIG. 11 a housing part with receptacles for springs and a receptacle for an actuator;

[0130] FIG. 12 a forming machine in the form of a bending press with electromechanical drives;

[0131] FIG. 13 a control device with an electromechanical drive;

[0132] FIG. 14 in a first embodiment, the time characteristic of the drive torque of the drive source and the braking torque of the braking device;

[0133] FIG. 15 in a second embodiment, the time characteristic of the (essentially constant) drive torque of the drive source and the (intermittent) braking torque of the braking device during intermittent working movement;

[0134] FIG. 16 in a third embodiment, the time characteristic of the (intermittent) drive torque and the (intermittent) braking torque during intermittent working movement;

[0135] FIG. 17 the path made by a forming tool during a forming step;

[0136] FIG. 18 an attachment part for the rotational part.

[0137] First of all, it is to be noted that in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclosures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position.

[0138] The exemplary embodiments show possible embodiment variants, and it should be noted in this respect that the invention is not restricted to these particular illustrated embodiment variants of it, but that rather also various combinations of the individual embodiment variants are possible and that this possibility of variation owing to the technical teaching provided by the present invention lies within the ability of the person skilled in the art in this technical field.

[0139] The scope of protection is determined by the claims. Nevertheless, the description and drawings are to be used for construing the claims. Individual features or feature combinations from the different exemplary embodiments shown and described may represent independent inventive solutions. The object underlying the independent inventive solutions may be gathered from the description.

[0140] All indications regarding ranges of values in the present description are to be understood such that these also comprise random and all partial ranges from it, for example, the indication 1 to 10 is to be understood such that it comprises all partial ranges based on the lower limit 1 and the upper limit 10, i.e. all partial ranges start with a lower limit of 1 or larger and end with an upper limit of 10 or less, for example 1 through 1.7, or 3.2 through 8.1, or 5.5 through 10.

[0141] Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size.

[0142] FIG. 1 shows an electromechanical spindle drive 1 comprising a housing 13, a motor 2 and a rotational part 3 which can be set in rotation about a rotation axis 4 by the motor 2. The rotational part 3 is configured as a spindle nut. A spindle 23 interacts with the rotational part 3.

[0143] The threaded portion (external thread) of the spindle 23 is arranged inside the rotational part 3 and interacts there, preferably via rolling elements 45, with the internal thread of the rotational part 3, which is configured as a spindle nut. The spindle 23 exits the rotational part 3 at a spindle outlet end 35.

[0144] The motor 2 has a stator 2a, which is mounted e.g. on the inside of the housing 13 (e.g. in the form of windings), and a rotor 2b, which is e.g. connected to the rotational part 3 and/or arranged directly on the rotational part 3 (e.g. in the form of permanent magnets). It is preferred that the stator 2a of the motor 2 surrounds the rotational part 3. The rotor 2b of the motor 2 may comprise pole elements, preferably in the form of permanent magnets, mounted, preferably removably, on the outside of the rotational part 3. Preferably, the motor 2 is a synchronous motor.

[0145] The spindle drive 1 also has bearings 37, 38 and 39 by means of which the rotational part 3 is rotatably mounted relative to the housing 13.

[0146] As can be seen from FIG. 1, at least one, preferably at least two, of the bearings 37 are arranged in the region of the spindle outlet end 35 of the rotational part 3 and/or are configured as a radial bearing. This is preferably a rolling bearing, in particular a ball bearing.

[0147] In the preferred embodiment of FIG. 1, the at least one bearing 37 arranged in the region of the spindle outlet end 35 of the rotational part 3 is arranged inside the rotational part 3, in this case on an inner side of the rotational part 3. It is located between the inside of the rotational part 3 and a bearing seat 36 projecting into the inside of the rotational part 3, which is formed on a housing part 13c, preferably a frontal housing cover, of the housing 13.

[0148] It may also be seen from FIG. 1 that the at least one bearing 37 arranged in the region of the spindle outlet end 35 of the rotational part 3 is arranged to overlap axially with the stator 2a and/or the rotor 2b of the motor 2. In other words, the bearings 37 are located within an area enclosed by the stator 2a and/or rotor 2b of the motor 2.

[0149] In the area of the end of the rotational part 3 opposite the spindle outlet end 35 a radial bearing 39 is arranged, by means of which the rotational part is mounted relative to the housing part 13a.

[0150] Also (an) axial bearing(s) 38 may be provided, preferably in the area between the motor 2 and a braking device 5.

[0151] The electromechanical drive 1 also comprises, in the embodiment shown, a braking device 5 which can be actuated between a braking position and a released position and is arranged in the area of the end of the rotational part 3 opposite the spindle outlet end 35. The braking device 5 has a brake disc 6 that rotates with the rotational part 3 and a braking element 7 that is adjustable in the axial direction and acts on the brake disc 6 in the braking position (see also FIGS. 2 and 3).

[0152] It can be seen from FIG. 4 that the brake disc 6 may have [0153] an inner area 8, [0154] a friction surface area 10 extending annularly around the rotational axis 4 with a first friction surface 11 configured on a first side of the brake disc 6, and [0155] an intermediate area 9 extending between the friction surface area 10 and the inner area 8 around the rotational axis 4.

[0156] A first mating surface 17 is configured on the braking element 7, which faces the first friction surface 11 and interacts with the first friction surface 11 in the braking position.

[0157] Preferably, the motor 2 and the braking device 5 are housed in a common housing 13.

[0158] In the preferred embodiment shown, the intermediate area 9 of the brake disc 6, both in the released position and in the braking position, has no contact with the braking element 7. In the braking position, the contact of the braking element 7 with the brake disc 6 is limited to the first friction surface 11 (see FIGS. 2, 7 and 9). As can also be seen, for example, in FIG. 5, the areas of the braking element 7 adjacent to the first mating surface 17 may be set back behind the mating surface 17.

[0159] In the preferred embodiment of the brake disc 6 shown in FIG. 4, the intermediate area 9 is a deformation area which is elastically deformable in the axial direction by the action of the braking element 7 on the brake disc 6 (see FIGS. 7 and 9).

[0160] In the deformation area, as shown in FIG. 4, cut-outs 19, preferably in the form of perforations, and/or material weakenings may be formed. It is preferred if, in the deformation area, the total area of the cut-outs 19 is at least as large as the total area occupied by the remaining material.

[0161] While the embodiments according to FIGS. 5-7 have only a first friction surface and a mating surface, the variants of FIGS. 1-3 and FIGS. 8 and 9 show that the friction surface area 10 may have a second friction surface 12 configured on the second side of the brake disc 6 opposite to the first side. The friction surface area 10 of the brake disc 6 is arranged between the first mating surface 17 and a second mating surface 18 facing the second friction surface 12 and cooperating with the second friction surface 12 in the braking position.

[0162] The brake disc 6 has a disc-shaped base body 24. The first friction surface 11 and the second friction surface 12 are each formed by a preferably annular brake lining, which is applied to the base body 24 and/or projects in the axial direction beyond the base body 26 (FIG. 5-9).

[0163] The first mating surface 17 and the second mating surface 18 are each annular. Several interrupted, e.g. segment-like arranged counter surface areas would also be conceivable.

[0164] As can be clearly seen from FIG. 4, the friction surface area 10 is preferably arranged in the periphery of the brake disc 6. The first friction surface 11 and/or the second friction surface 12 may extend to the outer edge of the brake disc 6. The difference between the outer radius and the inner radius of the friction surface area 10 is preferably at most ?, preferably at most ?, of the outer radius of the brake disc 6.

[0165] FIGS. 1 and 3 show that the electromechanical drive 1 has a (multi-part) housing 13. The second mating surface 18 may be formed on a housing part 13a or on an element that is firmly connected to the housing part 13a. In this way, the braking torque and the resulting frictional heat can be introduced directly into the housing.

[0166] In the embodiment shown in FIG. 4, the inner area 8 of the brake disc 6 has several, here annularly arranged, attachment interfaces 16, preferably in the form of holes, for attaching the brake disc 6 to the rotational part 3. Preferably, the number of attachment interfaces 16 is greater than 10 and/or greater than the number of cut-outs 19 in the deformation area. Due to a high number of fastening interfaces, a particularly precise adjustment of the brake disc relative to the mating surfaces is possible.

[0167] In the variants of FIGS. 6-9, in the released position of the braking device 5, the first friction surface 11 and the first mating surface 17 deviate from a parallel alignment. Similarly, the second friction surface 12 and the second mating surface 18 could deviate from a parallel alignment.

[0168] Preferably the distance between the first friction surface 11 and the first mating surface 17 decreases in the radial direction, this distance preferably being smaller at the radially outer edge of the first friction surface 11 by at most 1 mm, preferably by at most 0.2 mm, than at the radially inner edge of the first friction surface 11.

[0169] Similarly the distance between the second friction surface 12 and the second mating surface 18 decreases in the radial direction, this distance preferably being smaller at the radially outer edge of the second friction surface 12 by at most 1 mm, preferably by at most 0.2 mm, than at the radially inner edge of the second friction surface 12.

[0170] The friction surfaces and mating surfaces may be inclined to each other. The friction surfaces and mating surfaces may also have a curved shape in the radial direction.

[0171] As can be seen in particular from FIGS. 1-3, the inner area 8 of the brake disc 6 may be axially fixed to the rotational part 3. In the embodiments shown, the inner area 8 of the brake disc 6 is rigidly connected to the rotational part 3. This is done here by means of screws that protrude through the holes (attachment interfaces 16; see FIG. 4) and press the brake disc against the rotational part 3.

[0172] In the embodiment of FIG. 3, it can be seen that a first spacer ring 14 is arranged between the inner area 8 of the brake disc 6 and the rotational part 3. The inner area 8 of the brake disc 6 is also sandwiched between the first spacer ring 14 and a second spacer ring 15. This is done with the same screws as mentioned above that firmly connect the brake disc 7 to the rotational part 3.

[0173] In the preferred embodiment shown the electromechanical drive 1 is a spindle drive, wherein the rotational part 3 to which the brake disc 6 is connected is configured as a threaded nut which cooperates with the spindle 23 of the spindle drive. The lower end of the spindle 23 moves, when the motor is actuated and the threaded nut (rotational part 3) rotates, linearly downwards or upwards along the rotational axis 4 (FIG. 1).

[0174] The braking element 7 may be biased towards the braking position. Finally, FIGS. 10 and 11 show that the braking element 7 is biased towards the braking position by a plurality of springs 21 arranged in an annular manner and preferably overlapping with the first mating surface 17.

[0175] The springs 21 may be inserted in a removable housing part 13b (e.g. in the form of a cover or a front cover) of the electromechanical drive 1.

[0176] In FIGS. 1-3 and 10, it can be seen that the braking device 5 comprises an actuator 22, preferably in the form of an electromagnet, by means of which the braking element 6 can be brought into the released position and/or into the braking position. The actuator 22 as the springs 21 may be inserted in a removable housing part 13b of the electromechanical drive 1.

[0177] It can be seen from FIG. 1 that the spindle drive 1 may be a rolling spindle drive in which rolling elements 45, in particular in the form of balls, are guided in a circulating path. A first portion of the circulation path is formed between the internal thread of the rotational part 3 and the external thread of the spindle 23 and a second portion is formed by a return channel 44. In the embodiment shown, the return channel 44 is formed inside the spindle 23.

[0178] FIGS. 1 and 18 show that at the end of the rotational part 3 opposite the spindle outlet end 35, an attachment part 40 is connected to the rotational part 3, preferably the attachment part 40 having a portion located inside the rotational part 3 and/or forming a stop for the spindle 23. A portion 46 of the attachment part 40 located outside the rotational part 3 may be configured as a pin, the longitudinal axis of the pin-shaped portion 46 coinciding with the rotational axis 4 of the rotational part 3. The maximum diameter of the portion of the attachment part 40 located inside the rotation part 3 is preferably at least 3 times, preferably at least 4 times, as large as the diameter of the pin-shaped portion 46. The portion 46 of the attachment part 40 located outside the rotation part 3 is within the detection range of a sensor device 47, which is preferably a rotary encoder detecting the rotation of the attachment part 40.

[0179] A lubricant channel 41 may be configured in the attachment part 40 for supplying lubricant to the interior of the rotational part 3. The form of a first portion 42 of the lubricant channel 41, preferably in a portion 46 of the attachment part 40 located outside the rotational part 3, may be aligned with the rotational axis 4 of the rotational part 3.

[0180] The form of a second portion 43 of the lubricant channel 41 has a radial component with respect to the rotational axis 4 and/or is oblique to the rotational axis 4 (FIGS. 1 and 18). The second portion 43 of the lubricant channel 41 runs in a portion of the attachment part 40 located inside the rotation part 3 or ends at an outlet point 48, which with respect to the rotational axis 4 is located in a peripheral area of the attachment part 40.

[0181] In the embodiment shown, the attachment part 40 is surrounded by the braking device 5 of the spindle drive 1. In this case, the attachment part 40 may be disposed in a central recess of the brake disc 6 and even form a preferably positive receptacle for the brake disc 6 and thus perform a centring function for the brake disc.

[0182] On the outside of the housing 13, at least in the area of the motor 2, (e.g. removable) cooling fins 49 may be arranged.

[0183] The spindle drive 1 may have modular design, whereby a spindle drive component set may also be provided for the manufacture and/or adaptation of spindle drives. Such a component set comprises components for several electro-mechanical spindle drives 1. It is provided with components of various types and the components have connection interfaces for connecting the components to each other. Components of the same type have different sizes, wherein the connection interfaces of different sized components of the same type have the same dimensions.

[0184] In one example, the component set comprises [0185] first housing parts of different length and/or width, and [0186] second housing parts of different length and/or width, wherein the connection interfaces of the first housing parts for connection to the second housing parts have the same dimensions for all first housing parts and for all second housing parts.

[0187] In one example, the component set comprises [0188] rotational parts of different length and/or width, and [0189] housing parts of different length and/or width and/or motors of different length and/or width, [0190] wherein the connection interfaces of the rotational parts for connection to the housing parts and/or motors have the same dimensions for all rotational parts and/or wherein the connection interfaces of the housing parts and/or motors for connection to the rotational parts have the same dimensions for all housing parts and/or motors.

[0191] Finally, FIG. 12 shows a forming machine 20 in the form of a bending press, with at least one drive for the working movement (of a forming tool), in particular a press drive. The drive(s) are designed as electromechanical drive(s) 1 according to the invention. Such a forming machine may comprise a first (e.g. upper) tool carrier 25 (for holding at least a first forming tool 28) and a second (e.g. lower) tool carrier 26 (for holding at least a second forming tool 29), the relative movement of which is the working movement. Here, as shown in FIG. 12, the second tool carrier 26 may be stationary, while the first tool carrier 25 may be moved by the drive(s) 1. The electromechanical drive described above is particularly well suited for use in a bending machine, as the proposed braking device reacts in a particularly prompt way, thus reliably protecting the operating personnel in particular (especially in cases where a shutdown or a stop/slowdown of the working movement is relevant for safety) but also protecting workpieces from incorrect or faulty machining routines.

[0192] FIG. 12 shows a forming machine (in the form of a bending machine) for forming (bending) a preferably plate-type workpiece 27. The forming machine 20 comprises at least one electro-mechanical drive 1 having an electrical drive source 2 which in the embodiment according to FIG. 12 represents a press drive.

[0193] The forming machine comprises at least one forming tool 28, the working movement 32 of which is effected by the electromechanical drive 1, and at least one braking device 5, which can be actuated between a released position and a braking position, for braking and/or blocking the working movement 32 of the forming tool 28 (see FIG. 13).

[0194] In a method for forming a preferably plate-type workpiece 27 with a forming machine 20, the motor 2 of the electromechanical spindle drive 1 and/or the braking device 5 for forming the workpiece 27 is controlled by a control device 30.

[0195] FIGS. 14 and 15 now show schematically preferred methods for forming a workpiece 17. In FIG. 14, it may be seen that prior to a movement phase 33 of the forming tool 28, the electric drive source 2 generates a drive torque M while the braking device 5 is in the braking position, so that the braking torque B of the braking device 5 counteracts the drive torque M of the electric drive source 2. The start of the movement phase 33 of the forming tool 28 is triggered by transferring the braking device 5 to the released position and/or to a position with reduced braking torque.

[0196] In FIG. 15, it may additionally be seen that during a forming step the working movement 32 of the forming tool 28 is intermittent.

[0197] The single movement phases 33 of the working movement 32 of the forming tool 28 are shown schematically in FIG. 17. The distance travelled by the forming tool 28 during an intermittent working movement 32 is made up of the distance portions travelled during the individual movement phases 33 of the intermittent working movement 32. It may also be seen here that the direction of movement of the forming tool 28 may remain unchanged during the single movement phases 33 of an intermittent working movement 32.

[0198] Finally, FIG. 16 shows a variant in which the drive torque M of the electric drive source 2 is also generated intermittently in order to achieve an intermittent working movement.

[0199] The working movement 32 of the forming tool 28 preferably comprises several movement phases 33 during a forming step, wherein the movement phases 33 are interrupted by phases 34 in which the forming tool 28 is stationary or is moved at a lower speed than in the movement phase 33. Preferably, the length of a single movement phase 33 is less than 3 seconds, preferably less than 1.5 seconds. Preferably, the length of each phase 34 in which the forming tool 28 is stationary or is moved at a lower speed than in the movement phase 33 is less than 3 seconds, preferably less than 1.5 seconds. In this way, for example, a hammering action of the forming tool 28 on the workpiece 27 can be achieved.

[0200] From the variant according to FIG. 15 it may be seen that an intermittent working movement of the forming tool 28 is effected by an intermittent actuation of the braking device 5 between the released position and the braking position. The braking torque B acting on the rotational part 3 may. during those phases of the intermittent actuation of the braking device 5 in which the braking device 5 is in the braking position, be higher than the driving torque M acting on the rotational part 3. In this case, the actuation of the braking device 5 results in a (brief) stop of the forming tool 28.

[0201] The electrical drive source 2 may also generate a drive torque M during those phases of intermittent actuation of the braking device 5 in which the braking device 5 is in the braking position. For example, the drive torque M may be kept substantially constant during a forming step with intermittent working movement 32 of the forming tool 28.

[0202] From FIG. 13 as well as from the preferred embodiments of FIGS. 1 to 9 described in detail later, it may be seen that the electromechanical drive 1 comprises a rotational part 3 and the braking device 5 acts on the rotational part 3. The electrical drive source 2, which may be a motor, also acts on the rotational part 3 with its drive torque M.

[0203] In the case of an electric motor, the drive source 2 may comprise a stator 2a, e.g. connected to the housing 13 and/or stationary relative to the housing 13, and a rotor 2b, e.g. connected to the rotational part 3 or arranged directly on the rotational part 3. Corresponding supply and/or control lines lead to the electrical drive source 2.

[0204] As described in more detail later using the example of a spindle drive, the electro-mechanical drive 1 may comprise a transmission mechanism, in particular a linear drive, which converts the rotation of the rotational part 3 into a linear movement of a transmission element 23, which acts directly or indirectly on the forming tool 28. The transmission element 23 may, for example, be configured as a spindle or a toothed rack (on which a rotating gear wheel acts).

[0205] The braking device 5 is, as shown in FIG. 13 preferably, integrated in the electro-mechanical drive 1. The electrical drive source 2 and the braking device 5 may be housed in the same housing 13.

[0206] FIG. 13 also shows a control device 30 of the forming machine 20 for controlling the electric drive source 2 and the braking device 5. An operating mode 31 is stored in the control device 30, by means of which the electric drive source 2 and the braking device 5 can be controlled in such a way that the procedures described above can be carried out. The interaction between drive source 2 and braking device 5 has already been described in detail above. The (counter-)action of drive torque M and braking torque B enables the advantages mentioned in the introduction to the description.

TABLE-US-00001 List of reference signs 1 electromechanical drive 2 motor 2a stator 2b rotor 3 rotational part 4 rotational axis 5 braking device 6 brake disc 7 braking element 8 inner area 9 intermediate area 10 friction surface area 11 first friction surface 12 second friction surface 13 housing 13a housing part 13b housing part 13c housing part 14 first spacer ring 15 second spacer ring 16 attachment interface 17 first mating surface 18 second mating surface 19 cut-outs 20 forming machine 21 spring 22 actuator 23 spindle 24 base body 25 first tool carrier 26 second tool carrier 27 workpiece 28 forming tool 29 forming tool 30 control device 31 operating mode 32 working movement 33 movement phase 34 phase 35 spindle outlet end 36 bearing seat 37 bearing in the area of the spindle outlet end 38 axial bearing 39 radial bearing 40 attachment part 41 lubricant channel 42 first portion of the lubricant channel 43 second portion of the lubricant channel 44 return channel 45 rolling elements 46 pin-shaped portion 47 sensor device 48 outlet point 49 cooling fin B braking torque M drive torque