ELECTROMECHANICAL SPINDLE DRIVE

Description

[0001] The invention relates to an electromechanical spindle drive according to the preamble of claim 1. The invention also relates to a spindle drive component set, a forming machine and a method for forming a workpiece.

[0002] German patent DE 112014005384T5 discloses a motor that moves a rod in a forward and reverse direction along a central axis of the rod. The rod has a first screw groove in a spiral shape. The motor also has a ball nut, arranged on a radially inner side of a hollow shaft, with a second screw groove in a spiral shape, wherein a plurality of balls are arranged between the first screw groove and the second screw groove. The motor further comprises a stator and a plurality of magnets, arranged on a radially inner side of the stator and fixed to an outer surface of the hollow shaft. The hollow shaft is supported by a rear bearing and a front bearing.

[0003] Various types of forming machines, particularly bending machines, are known from the prior art. These machines typically use a hydraulic press drive, the actuation of which initiates the working movement of one or more forming tools. Braking devices are provided to increase machine safety and, in particular, to protect personnel.

[0004] In a completely different field, EP1524455A2 discloses, in connection with an electrically actuated linear actuator in the form of a spindle drive, a motor which drives a drive shaft within the drive housing via a gearbox. A braking device is also provided, comprising an axially movable first clutch disc and a second clutch disc that interacts with the drive shaft via a hub. The first clutch disc presses the second clutch disc against a third clutch disc. By actuating a coil, the first clutch disc is moved into a releasing position, allowing the second clutch disc to rotate with the drive shaft.

[0005] EP2333380A1 also discloses, in connection with a linear actuator as a drive source, a motor and a braking device with a rotating brake disc and a stationary brake disc which is movable relative to the rotating brake disc and enables braking of the drive shaft by means of friction.

[0006] The disadvantages arising from the prior art consist, in particular, of the fact that the drives disclosed therein and their operation are not suitable for the application of forming workpieces, especially for forming steps that must be precise and reproducible. It should also be mentioned that the braking effect, in particular the braking torque or braking force, is too low for certain applications. The braking process, i.e., the time that elapses between actuation of the braking device and the braking effect (e.g., the drive coming to a standstill or deceleration to a desired level), is often too long.

[0007] A significant disadvantage of spindle drives known from the prior art is their large size. Therefore, such spindle drives are often unsuitable for applications where space is a critical factor.

[0008] The object of the present invention was to overcome the disadvantages of the prior art and to provide a spindle drive in which a reliable and space-saving design is ensured, in particular ensuring the transmission of force or motion via the rotating part to the spindle.

[0009] In one variant, a method for forming a workpiece is to be provided that, on the one hand, achieves an immediate and rapid effect of the forming tool on the workpiece and, on the other hand, increases the efficiency and accuracy of the workpiece forming. Furthermore, the respective effect of the forming tool should be as precisely defined as possible, particularly with regard to the magnitude of the applied force and / or the duration of the force application. In addition, the time required for workpiece forming should be reduced, especially in cases where a forming step comprises several sub-steps. In preferred embodiments, the braking effect and the efficiency of the braking process or the application of the braking torque should also be increased.

[0010] This problem is solved by a spindle drive of the type mentioned above in that at least one – preferably at least two – of the bearings is / are arranged in the area of ​​the spindle exit end of the rotating part. These measures improve the bearing of the rotating part.

[0011] The invention is further characterized in that the at least one bearing, located in the region of the spindle exit end of the rotating part, is arranged within the rotating part, preferably on an inner surface of the rotating part. This measure significantly reduces the required installation space, particularly the dimensions perpendicular to the axis of rotation. Here, the space already available within the rotating part for the bearing is utilized.

[0012] A preferred embodiment is characterized in that the at least one bearing, located in the region of the spindle exit end of the rotating part, is arranged between the inside of the rotating part and a bearing receptacle projecting into the interior of the rotating part, wherein the bearing receptacle is preferably formed on a housing part, preferably an end-face housing cover, of the housing. This ensures reliable support of the bearing, for which housing parts can preferably be used. This allows for a further reduction in installation space and weight.

[0013] A preferred embodiment is characterized in that the at least one bearing, located in the region of the spindle exit end of the rotating part, is arranged axially overlapping with the stator and / or rotor of the motor and / or is located within a region enclosed by the stator and / or rotor of the motor. This measure also reduces the axial dimension of the spindle drive because the bearing does not abut the motor axially, but rather overlaps it. In other words, the bearing and the motor (stator and / or rotor) are located at least partially at the same axial height.

[0014] A preferred embodiment is characterized in that the at least one bearing arranged in the area of ​​the spindle exit end of the rotating part is a rolling bearing, in particular a ball bearing.

[0015] A preferred embodiment is characterized in that at least one of the bearings, preferably a radial bearing, is arranged in the region of the end of the rotating part opposite the spindle exit end.

[0016] A preferred embodiment is characterized in that at least one of the bearings is an axial bearing, which is preferably arranged in the area between the motor and a braking device of the electromechanical spindle drive. This measure reduces the required installation space because the axial bearing is arranged in an area where space is already available.

[0017] A preferred embodiment is characterized in that the stator of the motor surrounds the rotating part and / or that the rotor of the motor comprises pole elements, preferably in the form of permanent magnets, attached to the outside of the rotating part, preferably detachably, and / or that the motor is a synchronous motor.

[0018] A preferred embodiment is characterized in that the spindle drive is a roller spindle drive in which rolling elements, particularly in the form of balls, are guided in a circulating track, wherein a first section of the circulating track is formed between the internal thread of the rotating part and the external thread of the spindle, and a second section is formed by a return channel, the return channel being located inside the spindle. Arranging the return channel in the spindle also saves space, as the walls of the rotating part (which would otherwise have to accommodate the return channel) can be made thinner.

[0019] A preferred embodiment is characterized in that an attachment part is connected to the rotating part at the end opposite the spindle exit end. Preferably, the attachment part has a section located within the rotating part and / or forms a stop for the spindle. The attachment part is rotationally fixed (positive locking and / or friction locking), preferably rigidly, to the rotating part and therefore rotates with it. Depending on requirements, the attachment part can fulfill various functions: as a cover, as an interface for supplying lubricant to the interior of the rotating part, as a connection to a sensor device, etc.

[0020] A preferred embodiment is characterized in that a section of the attachment located outside the rotating part is designed in the form of a pin, wherein the longitudinal axis of the pin coincides with the axis of rotation of the rotating part, and wherein preferably the maximum diameter of the section of the attachment located inside the rotating part is at least 3 times, preferably at least 4 times, the diameter of the pin. The pin can pass through other structures and / or components (such as sensor devices, braking devices, etc.), e.g., to a lubricant connection.

[0021] A preferred embodiment is characterized in that the spindle drive includes a sensor device, wherein a section of the attachment located outside the rotating part lies within the detection range of the sensor device, wherein the sensor device is preferably a rotary encoder that detects the rotation of the attachment part.

[0022] A preferred embodiment is characterized in that a lubricant channel is formed in the attachment part for supplying lubricant to the interior of the rotating part.

[0023] A preferred embodiment is characterized in that the course of a first section of the lubricant channel is aligned with the axis of rotation of the rotating part, wherein preferably the first section of the lubricant channel runs in a section of the attachment part located outside the rotating part. The first section can terminate in a lubricant inlet which is connected to a (lubricant) supply line or supply device.

[0024] A preferred embodiment is characterized in that the course of a second section of the lubricant channel has a radial component with respect to the axis of rotation and / or is inclined to the axis of rotation, wherein preferably the second section of the lubricant channel runs in a section of the attachment located within the rotating part and / or terminates (inside the rotating part) at an outlet point that is arranged in a peripheral region of the attachment with respect to the axis of rotation. The lubricant serves to lubricate the internal thread of the rotating part and the external thread of the spindle, as well as, optionally, the roller elements arranged between them.

[0025] A preferred embodiment is characterized in that the attachment part is surrounded by a braking device of the spindle drive, wherein the attachment part preferably lies within a central recess of a brake disc of the braking device and / or forms a preferably positive-locking receptacle for a brake disc of the braking device. The attachment part can thus be used for centering and / or positioning the brake disc.

[0026] A preferred embodiment is characterized in that cooling fins are arranged on the outside of the housing - at least in the area of ​​the motor - and preferably the cooling fins are removable from the housing body.

[0027] A preferred embodiment is characterized by the fact that the spindle drive has a modular design.

[0028] A preferred embodiment is characterized in that the spindle drive has a braking device that can be actuated between a braking position and a released position, wherein the braking device acts on the rotating part, and preferably the braking device is arranged in the area of ​​the end of the rotating part opposite the spindle exit end.

[0029] A preferred embodiment is characterized in that the braking device has a brake disc that rotates with the rotating part and a brake element that is adjustable in the axial direction and acts on the brake disc in the braking position.

[0030] A preferred embodiment is characterized in that the brake disc an inner area, a ring-shaped friction surface area extending around the axis of rotation with a first friction surface formed on a first side of the brake disc, and an intermediate area extending between the friction surface area and the inner area around the axis of rotation, exhibits, and that a first counter surface is formed on the brake element, which faces the first friction surface and interacts with the first friction surface in the braking position.

[0031] The brake element does not rotate with the rotating part. In other words, the brake element is stationary with respect to the rotation of the rotating part or the brake disc connected to it. In the braking position, the brake element exerts a braking effect through frictional engagement with the brake disc. According to the embodiment of the invention, the friction surface area is located radially outside the inner area and also outside the intermediate area. While the inner area can serve as a mounting area (for attachment to the rotating part), the intermediate area is preferably deformable. It is preferred if the inner area and the intermediate area are not in contact with the brake element even in the braking position. The braking effect is greatest in the peripheral area. This is because the speed is highest there, and the greatest braking torque can also be applied there.

[0032] The brake element can be moved axially from the released position to the braked position. This movement reduces the brake gap until the brake element's first mating surface presses against the first friction surface of the brake disc.

[0033] The braking torque is transferred to the rotating part via the radially inner areas (inner area and intermediate area).

[0034] The brake disc can be axially fixed relative to the rotating part, with its inner area being fixed in place. In the braking position, the brake element presses against the outer friction surface area, exerting a deformation force on the brake disc. The disc tends to bend in the axial direction.

[0035] The rotating part can be, for example, a drive shaft, a threaded nut (e.g., in a spindle drive), a rotor (of an electric motor), or any rotating element of a drive train.

[0036] A preferred embodiment is characterized in that the intermediate area of ​​the brake disc – both in the released position and in the braked position – is free of contact with the brake element and / or that, in the braked position, the contact of the brake element with the brake disc is limited to the first friction surface. This measure ensures that the frictional connection is established only in the area of ​​the friction surfaces, while the inner area and the intermediate area do not come into direct contact with the brake element. In particular, the intermediate area can thus perform an additional function.

[0037] A preferred embodiment is characterized in that the intermediate area is a deformation zone that can be elastically deformed in the axial direction by the action of the braking element on the brake disc. In contrast to known solutions, the brake disc can be axially fixed to the rotating part. A rigid connection between the brake disc and the rotating part can also be provided. This increases the braking effect, and in particular, the braking force is transmitted directly to the rotating part.

[0038] A preferred embodiment is characterized by the inclusion of cutouts, preferably in the form of openings, and / or material weakenings in the deformation zone. The degree of deformability can be determined and optimized for various applications by the number of cutouts. Alternatively, the deformation zone can also be characterized by a reduced material thickness compared to the inner area and / or the friction surface area.

[0039] A preferred embodiment is characterized in that, in the deformation zone, the total area of ​​the cutouts is at least as large as the total area occupied by the remaining material. This ensures sufficient deformation, particularly in the case where the friction surface area is pressed against a second counter surface in the braking position.

[0040] A preferred embodiment is characterized in that the friction surface area has a second friction surface formed on the second side of the brake disc, opposite the first side, and that the friction surface area of ​​the brake disc is arranged between the first mating surface and a second mating surface facing the second friction surface and interacting with the second friction surface in the braking position. In the released position of the brake device, a brake gap is formed between the respective interacting surfaces. By means of a deformable intermediate area, it can be elegantly ensured—as an alternative to axial displacement of the brake disc relative to the rotating part—that the brake gap(s) are completely closed by deformation of the brake disc in the axial direction.

[0041] A preferred embodiment is characterized in that the first counter surface is annular and / or that the second counter surface is annular.

[0042] A preferred embodiment is characterized in that the friction surface area is arranged in the periphery of the brake disc, with the first friction surface and / or the second friction surface preferably extending to the outer edge of the brake disc. As already mentioned, the braking effect is greatest in the outermost area of ​​the brake disc.

[0043] A preferred embodiment is characterized in that the difference between the outer radius and the inner radius of the friction surface area is at most 1 / 3, preferably at most 1 / 4, of the outer radius of the brake disc.

[0044] A preferred embodiment is characterized in that the electromechanical drive has a housing and that the second mating surface is formed on a housing part or on an element rigidly connected to the housing part. This allows the braking torque to be introduced directly into the (stationary) housing. The braking energy dissipated as heat can also be transferred into the housing, thus eliminating the need for complex brake cooling, as the heat can be conducted directly to the outside via the housing.

[0045] A preferred embodiment is characterized in that the inner area of ​​the brake disc has at least one, preferably several – preferably ring-shaped – fastening interfaces, preferably in the form of holes, for fastening the brake disc to the rotating part, wherein the number of fastening interfaces is preferably greater than 10 and / or greater than the number of cutouts in the deformation area. A rigid connection between the brake disc and the rotating part, which can be ensured, for example, by screws, is particularly preferred.

[0046] A preferred embodiment is characterized in that, in the released position of the brake device, the first friction surface and the first counter surface deviate from a parallel alignment, and / or that, in the released position of the brake device, the second friction surface and the second counter surface deviate from a parallel alignment. This measure allows, for example, the pressure to be reduced on a more inner section of the friction surface area, while it can be increased relative to this on a more outer section. With appropriate dimensioning of the friction or counter surface(s) (or the brake gap), this results in a more uniform pressure distribution. This leads to less wear and an increased service life. These advantages can also be achieved, for example, by the following preferred embodiments.

[0047] A preferred embodiment is characterized by the fact that that the distance between the first friction surface and the first counter surface decreases in the radial direction, wherein preferably this distance is at most 1 mm, preferably at most 0.2 mm, smaller at the radial outer edge of the first friction surface than at the radial inner edge of the first friction surface, and / or that the distance between the second friction surface and the second counter surface decreases in the radial direction, wherein preferably this distance is at most 1 mm, preferably at most 0.2 mm, smaller at the radial outer edge of the second friction surface than at the radial inner edge of the second friction surface. In the braking position, the pressure is reduced on a more inner section of the friction surface area, while it is increased relative to this on a more outer section. This also allows for a certain degree of adaptation to a brake disc that flexes axially during braking.

[0048] A preferred embodiment is characterized in that, in the released position of the brake device, the first friction surface and the first counter surface are inclined towards each other and / or that, in the released position of the brake device, the second friction surface and the second counter surface are inclined towards each other.

[0049] A preferred embodiment is characterized in that the first friction surface and / or the first counter surface has a curved profile in the radial direction and / or that the second friction surface and / or the second counter surface has a curved profile in the radial direction.

[0050] A preferred embodiment is characterized in that the inner area of ​​the brake disc is axially fixed to the rotating part and / or that the inner area of ​​the brake disc is rigidly connected to the rotating part, preferably by means of screws.

[0051] A preferred embodiment is characterized in that a first spacer ring is arranged between the inner area of ​​the brake disc and the rotating part, wherein the inner area of ​​the brake disc is preferably clamped between the first spacer ring and a second spacer ring, preferably by means of screws. The spacer ring(s) can be used to adjust or optimize the relative position of the friction surface(s) relative to the counter surface(s). They also ensure a uniform pressure distribution.

[0052] A preferred embodiment is characterized in that the electromechanical drive is a spindle drive, wherein the rotating part to which the brake disc is connected is designed in the form of a threaded nut which interacts with the spindle of the spindle drive.

[0053] A preferred embodiment is characterized in that the brake disc has a disc-shaped base body and that the first friction surface and / or the second friction surface is formed by a preferably ring-shaped brake pad which is applied to the base body and / or projects axially beyond the base body.

[0054] A preferred embodiment is characterized in that the brake element is pre-tensioned in the direction of the braking position. Independent of actuation or energizing, the braking position can therefore be maintained by passive (spring) elements.

[0055] A preferred embodiment is characterized in that the brake element is pre-tensioned in the direction of the braking position by a plurality of springs which are arranged in a ring shape and preferably overlapping with the first counter surface.

[0056] A preferred embodiment is characterized in that the springs are installed in a removable housing part of the electromechanical drive.

[0057] A preferred embodiment is characterized in that the braking device comprises an actuator – controllable by the control unit – preferably in the form of an electromagnet, by which the braking element can be moved into the released position and / or into the braking position, wherein the actuator is preferably installed in a removable housing part of the electromechanical drive. Such a variant has the advantage that in the event of a power failure or a control error, the electromagnets are de-energized and the braking device automatically falls into the braking position.

[0058] A preferred embodiment is characterized in that the braking device is integrated into the electromechanical drive and / or that the motor and the braking device are housed in a common casing. This increases the immediacy of the braking effect, since braking takes place in the immediate vicinity of the motor torque generation.

[0059] The invention also relates to a spindle drive component set comprising components for several electromechanical spindle drives according to the invention, wherein the component set includes components of various types and the components have connection interfaces for connecting the components to one another, and wherein components of the same type have different sizes, the connection interfaces of differently sized components of the same type being dimensioned identically. This measure allows a spindle drive to be easily adapted to the given requirements. Size, power, force, (spindle) stroke, weight, and cooling capacity can serve as criteria for selecting the desired components and assembling them into a spindle drive according to the invention. The connection interfaces can be mechanical interfaces (fastening points or mechanisms) for housing parts, rotating parts, spindles, and motor parts (such as, for example, a motor).variable number of pole elements on the rotating part), etc., electrical and control-related interfaces e.g. for motor, brake device and / or sensor device, hydraulic interfaces or fluid supply interfaces (lubricant).

[0060] A preferred embodiment is characterized in that the component set First housing parts of different lengths and / or widths and second housing parts of different lengths and / or widths The system features connection interfaces of the first housing parts for connection with the second housing parts, with identical dimensions for both first and second housing parts. This allows housing parts to be connected to other housing parts regardless of their size.

[0061] A preferred embodiment is characterized in that the component set Rotating parts of different lengths and / or widths, housing parts of different lengths and / or widths, and / or motors of different lengths and / or widths exhibits wherein the connection interfaces of the rotating parts for connection with the housing parts and / or motors are dimensioned the same for all rotating parts and / or wherein the connection interfaces of the housing parts and / or motors for connection with the rotating parts are dimensioned the same for all housing parts and / or motors.

[0062] The invention also relates to a forming machine, in particular a bending machine, for forming a workpiece, preferably in the shape of a plate, wherein the forming machine at least one electromechanical spindle drive according to the invention, at least one forming tool whose working movement is effected by the electromechanical drive, includes.

[0063] The invention also relates to methods for forming a workpiece, preferably plate-shaped, with a forming machine according to the invention, in particular a bending machine, wherein the motor of the electromechanical spindle drive for forming the workpiece is controlled by a control device.

[0064] In a preferred method for forming a workpiece, preferably plate-shaped, with a forming machine, in particular a bending machine, the forming machine comprises at least one electromechanical drive (spindle drive) with an electric drive source (motor), at least one forming tool whose working movement is effected by the electromechanical drive, and at least one braking device operable between a released position and a brake position, preferably in the form of a friction brake, for braking and / or blocking the working movement of the forming tool. Such an embodiment is characterized by the fact that that prior to a movement phase of the forming tool, the electric drive source generates a drive torque while the braking device is in the braking position, so that the braking torque of the braking device counteracts the drive torque of the electric drive source, and the start of the movement phase of the forming tool is triggered by moving the braking device into the released position and / or into a position with reduced braking torque, and / or that during a forming step the working movement of the forming tool is intermittent.

[0065] The workpiece to be formed is preferably a plate-shaped metal workpiece, in particular a sheet metal part. The forming machine is therefore preferably a sheet metal forming machine, in particular a bending machine, such as a press brake or a swing bending machine.

[0066] The process is controlled by a control unit. This control unit controls both the electrical drive and the braking system, thus enabling the control of the movement phase(s), particularly their commencement and / or sequence. In accordance with the process, the control unit actuates the electrical drive and the braking system, thereby controlling the drive torque (of the drive) and the braking torque (of the braking system). The drive and braking systems act – directly or indirectly – on the forming tool.

[0067] For example, an operating mode corresponding to the procedure can be stored in the control unit (e.g., alongside other operating modes).

[0068] This embodiment allows the working movement of the forming tool to be divided into individual movement phases, with the forming tool being stopped or slowed down between each phase. The division into these individual movement phases is achieved by the braking device. In other words, the working movement can be controlled by the braking device.

[0069] This embodiment has two key advantages. According to the first variant, the braking device serves to trigger the start of a movement phase. Thus, the braking device assumes a control function that relates not (only) to braking or stopping a work movement, but to triggering or releasing a movement. This type of control can be used not only for a single movement phase, but especially for intermittent (e.g., hammering) work movements with multiple interrupted movement phases. Here, the braking device's function is to control the sequence of movement phases.

[0070] The major advantage of this concept is that the drive torque from the power source does not need to be built up at the beginning of the movement phase (and thus at the beginning of the workpiece machining phase), but is already available. A rapid transition of the braking device to the released position results in the immediate application of the already available drive torque to the forming tool and thus to the workpiece. This creates a defined work step, which is also initiated by a pulse or shock that is precisely defined in terms of both timing and force, and is always accurately reproducible.

[0071] A further advantage is that a sequence of movement phases in intermittent operation is only made possible by the interaction of an electric drive source with an actuated braking device. Here, too, the process is controlled by the control unit. The control unit controls both the electric drive source and the braking device, thus enabling the control unit to manage the movement phase(s) of the intermittent movement, in particular their initiation and / or sequence.

[0072] The braking system includes an actuator connected to the control unit of the forming machine. The control unit thus switches the braking system between the released and braked positions by activating the actuator.

[0073] The braking device is preferably a friction brake. This allows for a particularly fast transition between the braked and released positions. As a result, the movement phases and the phases between the movement phases can each preferably be less than 1.5 seconds, preferably less than 1 second.

[0074] A preferred embodiment is characterized in that the direction of movement of the forming tool remains unchanged in the individual phases of an intermittent working movement and / or that the path traveled by the forming tool during an intermittent working movement is composed of the path segments traveled during the individual phases of the intermittent working movement. This is a progressive movement of the forming tool. For example, a bending step can be achieved through individual partial steps. The (repeating) impact movements of the forming tool can generate the necessary forming force.

[0075] A preferred embodiment is characterized in that the working movement of the forming tool during a forming step comprises several, preferably at least three, movement phases, wherein the movement phases are interrupted by phases in which the forming tool is stationary or is moved at a lower speed than in the movement phase, wherein preferably the length of each individual movement phase is less than 3 seconds, preferably less than 1.5 seconds, and / or wherein preferably the length of each phase in which the forming tool is stationary or is moved at a lower speed than in the movement phase is less than 3 seconds, preferably less than 1.5 seconds.

[0076] A preferred embodiment is characterized in that an intermittent working movement of the forming tool is effected by intermittent actuation of the braking device between the released position and the braked position. Here, the braking device assumes a control function, thereby ensuring precise and well-defined machining of the workpiece.

[0077] A preferred embodiment is characterized in that the electrical drive source also generates a drive torque during those phases of intermittent actuation of the braking device in which the braking device is in the braking position. The drive source does not have to build up a drive torque anew each time, which would be associated with a recurring latency at the beginning of each movement phase.

[0078] A preferred embodiment is characterized in that the drive torque of the motor is kept essentially constant during a forming step with intermittent working movement of the forming tool. This minimizes the control effort for the drive source, while control is achieved via the braking device.

[0079] A preferred embodiment is characterized in that the electromechanical drive comprises a rotating part and the braking device acts on the rotating part, wherein the electrical drive source is preferably a motor whose drive torque acts on the rotating part. Simple and efficient braking devices such as friction brakes, as well as powerful drives such as motors, can be used here.

[0080] A preferred embodiment is characterized in that the braking torque acting on the rotating part – during those phases of intermittent actuation of the braking device in which the braking device is in the braking position – is higher than the driving torque acting on the rotating part. This measure allows the movement of the forming tool to be brought to a standstill between the individual movement phases.

[0081] A preferred embodiment is characterized in that the electromechanical drive comprises a transmission mechanism, in particular a linear drive, which converts the rotation of the rotating part into a linear movement of a transmission element which acts directly or indirectly on the forming tool, wherein the transmission element is preferably designed in the form of a spindle.

[0082] A preferred embodiment is characterized in that the braking device is integrated into the electromechanical drive and / or that the electrical drive source and the braking device are housed in the same casing.

[0083] The invention also relates to a forming machine, in particular a bending machine, for forming a workpiece, preferably in the shape of a plate, wherein the forming machine at least one electromechanical drive with an electric drive source, at least one forming tool whose working movement is effected by the electromechanical drive, at least one braking device operable between a released position and a braking position for braking and / or blocking the working movement of the forming tool, and a control device for controlling the electric drive source and the braking device comprising, characterized in that an operating mode is stored in the control device by which the electrical drive source and the braking device can be controlled in such a way that, prior to a movement phase of the forming tool, the electrical drive source generates a drive torque while the braking device is in the braking position, so that the braking torque of the braking device counteracts the drive torque of the electrical drive source, and the start of the movement phase of the forming tool is triggered by moving the braking device into the released position and / or into a position with reduced braking torque, and / or that during a forming step the working movement of the forming tool is intermittent.

[0084] The forming machine is preferably a bending machine and can be designed, for example, as a bending press, in particular a press brake, or as a folding machine.

[0085] Such a forming machine can comprise a first (e.g., upper) tool carrier and a second (e.g., lower) tool carrier, the relative movement of which constitutes the working motion. One tool carrier can be stationary, while the other is movable by the electric drive.

[0086] The forming machine's at least one electric drive acts on a tool holder, preferably the upper tool holder. The forming tool is held by a tool holder.

[0087] A preferred embodiment is characterized in that the electromechanical drive comprises a rotating part and the braking device acts on the rotating part, wherein the electrical drive source is preferably formed by a motor whose drive torque acts on the rotating part.

[0088] Subsequent embodiments aim to increase the braking effect and the efficiency of the braking process or the application of the braking torque. This is intended to enhance safety, particularly in applications where operators work or handle equipment in hazardous areas and drives must therefore come to an immediate standstill under certain conditions. The reliability, performance, and applicability of an electromechanical drive in a wide range of applications are to be improved through enhanced braking technology.

[0089] A preferred embodiment of the forming device is characterized in that the control unit with the stored operating mode is configured to operate the forming machine according to a method, in particular according to one of the embodiments described above, by controlling the electrical drive source and the braking device.

[0090] A preferred embodiment of the method is characterized in that the forming machine is designed according to the invention, in particular according to one of the embodiments described above.

[0091] The objective is also achieved with a forming machine, in particular a bending machine, preferably a press brake, with at least one drive for the working movement, in particular a press drive, wherein the at least one drive is an electromechanical drive. Such a forming machine can comprise a first (e.g., upper) tool carrier and a second (e.g., lower) tool carrier, the relative movement of which constitutes the working movement. The electromechanical drive described above is particularly well suited for use in a forming machine, since the proposed braking device reacts particularly quickly and thus reliably protects the operating personnel (especially in cases where shutting down or stopping / slowing down the working movement is relevant for safety) and also protects workpieces from incorrect or faulty processing routines.

[0092] To better understand the invention, it is explained in more detail with reference to the following figures.

[0093] They each show, in a highly simplified, schematic representation: Fig. 1 an electromechanical drive in section; Fig. 2 a section of a braking device with a perspective view; Fig. 3 a braking device in section; Fig. 4 a brake disc; Fig. 5 the interaction of the brake element and the brake disc; Fig. 6 a braking device in the released position; Fig. 7 a braking device in the released position; Fig. 8 a braking device with a second braking and counter surface in the released position; Fig. 9 a braking device with a second braking and counter surface in the released position; Fig. 10 a braking device with a pre-tensioned brake element; Fig. 11 a housing part with receptacles for springs and a receptacle for an actuator; Fig. 12 a forming machine, in the form of a press brake, with electromechanical drives; Fig. 13 a control device with an electromechanical drive; Fig. 14 in a first embodiment the time course of the drive torque of the drive source and the braking torque of the braking device; Fig.15 in a second embodiment, the time course of the (essentially constant) drive torque of the drive source and the (intermittent) braking torque of the braking device during intermittent working movement; Fig. 16 in a third embodiment, the time course of the (intermittent) drive torque and the (intermittent) braking torque during intermittent working movement; Fig. 17 the path traveled by a forming tool during a forming step; Fig. 18 an attachment part for the rotating part. It should be noted at the outset that in the differently described embodiments, identical parts are provided with the same reference numerals or component designations, and the disclosures contained in the entire description can be applied analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the figure directly described and illustrated, and these positional designations must be applied analogously to the new position if the position changes.

[0094] The exemplary embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiment variants, but rather various combinations of the individual embodiment variants are also possible and this possibility of variation lies within the skill of the person skilled in this technical field due to the teaching on technical action by the present invention.

[0095] The scope of protection is defined by the claims. However, the description and drawings must be consulted for the interpretation of the claims. Individual features or combinations of features from the different embodiments shown and described can, in themselves, represent independent inventive solutions. The problem underlying these independent inventive solutions can be found in the description.

[0096] All references to value ranges in this description are to be understood as encompassing any and all sub-ranges thereof, e.g., the reference 1 to 10 is to be understood as including all sub-ranges, starting from the lower limit 1 and the upper limit 10, i.e., all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g., 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0097] Finally, for the sake of clarity, it should be noted that, for a better understanding of the structure, some elements have been shown not to scale and / or enlarged and / or reduced in size.

[0098] Fig. 1Figure 1 shows an electromechanical spindle drive 1 comprising a housing 13, a motor 2, and a rotating part 3, which can be rotated about a rotational axis 4 by the motor 2. The rotating part 3 is designed in the form of a spindle nut. A spindle 23 interacts with the rotating part 3. The threaded section (external thread) of the spindle 23 is arranged inside the rotating part 3 and interacts there—preferably via roller elements 45—with the internal thread of the rotating part 3, which is designed as a spindle nut. The spindle 23 exits the rotating part 3 at a spindle exit end 35.

[0099] The motor 2 has a stator 2a, which is mounted, for example, on the inside of the housing 13 (e.g., in the form of windings), and a rotor 2b, which is connected to the rotating part 3 and / or arranged directly on the rotating part 3 (e.g., in the form of permanent magnets). It is preferred that the stator 2a of the motor 2 surrounds the rotating part 3. The rotor 2b of the motor 2 can include pole elements, preferably in the form of permanent magnets, which are attached to the outside of the rotating part 3, preferably removable. The motor 2 is preferably a synchronous motor.

[0100] The spindle drive 1 also has bearings 37, 38 and 39, by means of which the rotating part 3 is rotatably mounted relative to the housing 13.

[0101] As from Fig. 1As can be seen, at least one – preferably at least two – of the bearings 37 are arranged in the region of the spindle exit end 35 of the rotating part 3 and / or are designed in the form of a radial bearing. This is preferably a rolling bearing, in particular a ball bearing.

[0102] In the preferred embodiment of the Fig. 1 This is at least one bearing 37 arranged in the region of the spindle exit end 35 of the rotating part 3, within the rotating part 3 – here on an inner surface of the rotating part 3. It is located between the inner surface of the rotating part 3 and a bearing receptacle 36 projecting into the interior of the rotating part 3, which is formed on a housing part 13c, preferably an end-face housing cover, of the housing 13.

[0103] Out of Fig. 1It can also be seen that at least one bearing 37, located in the region of the spindle exit end 35 of the rotating part 3, is arranged axially overlapping with the stator 2a and / or the rotor 2b of the motor 2. In other words, the bearings 37 are arranged within a region enclosed by the stator 2a and / or rotor 2b of the motor 2.

[0104] In the area of ​​the end of the rotating part 3 opposite the spindle exit end 35, a radial bearing 39 is arranged, by which the rotating part is supported relative to the housing part 13a.

[0105] An axial bearing 38 may also be provided, preferably in the area between the motor 2 and a brake device 5.

[0106] The electromechanical drive 1, in the illustrated embodiment, further comprises a braking device 5, which can be actuated between a braking position and a released position and is arranged in the region of the end of the rotating part 3 opposite the spindle exit end 35. The braking device 5 has a brake disc 6 that rotates with the rotating part 3 and an axially adjustable brake element 7, which acts on the brake disc 6 in the braking position (see also Fig. 2 and 3 ).

[0107] Out of Fig. 4 It is evident that the brake disc 6 an inner region 8, a friction surface area 10 extending in a ring shape around the axis of rotation 4 with a first friction surface 11 formed on a first side of the brake disc 6, and an intermediate region 9 extending between the friction surface area 10 and the inner region 8 around the axis of rotation 4, can exhibit.

[0108] A first counter surface 17 is formed on the brake element 7, which faces the first friction surface 11 and interacts with the first friction surface 11 in the braking position.

[0109] Preferably, the motor 2 and the brake device 5 are housed in a common housing 13.

[0110] In the illustrated preferred embodiment, the intermediate area 9 of the brake disc 6 is free of contact with the brake element 7 – both in the released position and in the braking position. In the braking position, the contact of the brake element 7 with the brake disc 6 is limited to the first friction surface 11 (see Fig. 2 , 7 and 9 ). As for example from Fig. 5 As can be seen, the areas of the brake element 7 adjacent to the first counter surface 17 may be set back behind the counter surface 17.

[0111] In the Fig. 4In the illustrated preferred embodiment of the brake disc 6, the intermediate area 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 (see Figs. 7 and 9 ).

[0112] In the deformation area, as in Fig. 4 The cutouts 19 shown are preferably formed in the form of openings and / or material weakenings. It is preferred that, in the deformation area, the total area of ​​the cutouts 19 is at least as large as the total area occupied by the remaining material.

[0113] While the embodiments according to Figs. 5-7 The variants of the only have a first friction and counter surface. Figs. 1-3 as well as Figs. 8 and 9The friction surface area 10 can have a second friction surface 12, which is formed on the second side of the brake disc 6, opposite the first side. The friction surface area 10 of the brake disc 6 is arranged between the first counter surface 17 and a second counter surface 18, which faces the second friction surface 12 and interacts with the second friction surface 12 in the braking position.

[0114] 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 ring-shaped brake pad, which is applied to the base body 24 and / or projects axially beyond the base body 26 ( Figs. 5-9 ).

[0115] The first counter surface 17 and the second counter surface 18 are each ring-shaped. Multiple interrupted counter surface areas, e.g., arranged in segments, would also be conceivable.

[0116] As from Fig. 4 As can be clearly seen, 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 can 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 1 / 3, preferably at most 1 / 4, of the outer radius of the brake disc 6.

[0117] Fig. 1 and 3 Show that the electromechanical drive 1 has a (multi-part) housing 13. The second mating surface 18 can be formed on a housing part 13a or on an element rigidly connected to the housing part 13a. In this way, the braking torque and the resulting frictional heat can be introduced directly into the housing.

[0118] In the Fig. 4In the illustrated embodiment, the inner area 8 of the brake disc 6 has several mounting interfaces 16 – arranged here in a ring – preferably in the form of holes, for attaching the brake disc 6 to the rotating part 3. The number of mounting interfaces 16 is preferably greater than 10 and / or greater than the number of cutouts 19 in the deformation area. A high number of mounting interfaces allows for particularly precise adjustment of the brake disc relative to the mating surfaces.

[0119] In the variants of Figs. 6-9 In the released position of the brake device 5, the first friction surface 11 and the first counter surface 17 deviate from a parallel alignment. Likewise, the second friction surface 12 and the second counter surface 18 could deviate from a parallel alignment.

[0120] Preferably, the distance between the first friction surface 11 and the first counter surface 17 decreases in the radial direction, wherein preferably this distance is less at the radial outer edge of the first friction surface 11 by at most 1 mm, preferably by at most 0.2 mm, than at the radial inner edge of the first friction surface 11.

[0121] Likewise, the distance between the second friction surface 12 and the second counter surface 18 can decrease in the radial direction, preferably this distance being less than 1 mm, preferably less than 0.2 mm, at the radial outer edge of the second friction surface 12 than at the radial inner edge of the second friction surface 12.

[0122] The friction surfaces and counter surfaces can be inclined towards each other. The friction surfaces and counter surfaces can also have a curved profile in the radial direction.

[0123] As can be seen particularly from the Figures 1-3As can be seen, the inner area 8 of the brake disc 6 can be axially fixed to the rotating part 3. In the illustrated embodiments, the inner area 8 of the brake disc 6 is rigidly connected to the rotating part 3. This is achieved here by means of screws that pass through the holes (fastening interfaces 16; see Fig. 4 ) protrude and press the brake disc against the rotating part 3.

[0124] In the embodiment of the 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 rotating part 3. The inner area 8 of the brake disc 6 is also clamped between the first spacer ring 14 and a second spacer ring 15. This is done with the same screws mentioned above that firmly connect the brake disc 7 to the rotating part 3.

[0125] In the preferred embodiment shown, the electromechanical drive 1 is a spindle drive, wherein the rotating part 3, to which the brake disc 6 is connected, is designed in the form of a threaded nut which interacts 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 (rotating part 3) rotates – linearly downwards or upwards along the axis of rotation 4 ( Fig. 1 ).

[0126] The brake element 7 can be pre-tensioned in the direction of the brake position. Figs. 10 and 11 Finally, show that the brake element 7 is pre-tensioned in the direction of the braking position by a plurality of springs 21, which are arranged in a ring shape and preferably overlapping with the first counter surface 17.

[0127] The springs 21 can be inserted in a removable housing part 13b (e.g. in the form of a lid or an end cover) of the electromechanical drive 1.

[0128] In the 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 which the braking element 6 can be moved into the released position and / or into the braking position. The actuator 22, as well as the springs 21, can be installed in a removable housing part 13b of the electromechanical drive 1.

[0129] Out of Fig. 1 It is evident that the spindle drive 1 can be a roller spindle drive in which rolling elements 45, in particular in the form of balls, are guided in a circulating path. A first section of the circulating path is between the internal thread of the rotating part 3 and the external thread of the spindle 23, and a second section is formed by a return channel 44. In the illustrated embodiment, the return channel 44 is formed inside the spindle 23.

[0130] Fig. 1 and 18The illustration shows that an attachment part 40 can be connected to the rotating part 3 at the end opposite the spindle exit end 35, wherein the attachment part 40 preferably has a section located within the rotating part 3 and / or forms a stop for the spindle 23. A section 46 of the attachment part 40 located outside the rotating part 3 can be designed in the form of a pin, wherein the longitudinal axis of the pin-shaped section 46 coincides with the axis of rotation 4 of the rotating part 3. The maximum diameter of the section of the attachment part 40 located inside the rotating part 3 is preferably at least 3 times, preferably at least 4 times, the diameter of the pin-shaped section 46.The section 46 of the attachment part 40, located outside the rotating part 3, lies within the detection range of a sensor device 47, which is preferably a rotary encoder that detects the rotation of the attachment part 40.

[0131] The attachment part 40 can have a lubricant channel 41 for supplying lubricant to the interior of the rotating part 3. The course of a first section 42 of the lubricant channel 41 – preferably in a section 46 of the attachment part 40 located outside the rotating part 3 – can be aligned with the axis of rotation 4 of the rotating part 3.

[0132] The course of a second section 43 of the lubricant channel 41 has a radial component with respect to the axis of rotation 4 and / or is oblique to the axis of rotation 4 ( Fig. 1 and 18). The second section 43 of the lubricant channel 41 runs in a section of the attachment part 40 located within the rotating part 3 or ends at an outlet point 48 which - with respect to the axis of rotation 4 - is located in a peripheral area of ​​the attachment part 40.

[0133] In the illustrated embodiment, the attachment part 40 is surrounded by the braking device 5 of the spindle drive 1. The attachment part 40 can lie within a central recess of the brake disc 6 and even form a preferably positive-locking receptacle for the brake disc 6, thus performing a centering function for the brake disc.

[0134] Cooling fins 49 (e.g. removable) can be arranged on the outside of the housing 13 - at least in the area of ​​the motor 2.

[0135] The spindle drive 1 can be modularly designed, allowing a spindle drive component set to be provided for the manufacture and / or adaptation of spindle drives. Such a component set comprises components for several electromechanical spindle drives 1. It includes components of various types, and these components have connection interfaces for connecting them to one another. Components of the same type have different sizes, with the connection interfaces of differently sized components of the same type being dimensioned identically.

[0136] In one example, the component set includes First housing parts of different lengths and / or widths and second housing parts of different lengths and / or widths on, wherein the connection interfaces of the first housing parts for connection with the second housing parts are dimensioned the same for all first housing parts and for all second housing parts.

[0137] In one example, the component set includes Rotating parts of different lengths and / or widths, housing parts of different lengths and / or widths, and / or motors of different lengths and / or widths on, wherein the connection interfaces of the rotating parts for connection with the housing parts and / or motors are dimensioned the same for all rotating parts and / or wherein the connection interfaces of the housing parts and / or motors for connection with the rotating parts are dimensioned the same for all housing parts and / or motors.

[0138] Fig. 12Figure 1 shows a forming machine 20 in the form of a press brake, 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 can comprise a first (e.g., upper) tool carrier 25 (for holding at least one first forming tool 28) and a second (e.g., lower) tool carrier 26 (for holding at least one second forming tool 29), the relative movement of which is the working movement. As shown in Figure 26, the tool carrier can be configured as follows: Fig. 12As shown, the second tool carrier 26 is stationary, while the first tool carrier 25 is movable by the drive(s) 1. The electromechanical drive described above is particularly well suited for use in a bending machine, since the proposed braking device reacts very quickly and thus reliably protects the operating personnel (especially in cases where switching off or stopping / slowing down the working movement is relevant for safety) and also protects workpieces from incorrect or faulty machining routines.

[0139] Fig. 12 Figure 20 shows a forming machine (in the form of a bending machine) for forming (bending) a workpiece 27, preferably in the shape of a plate. The forming machine 20 comprises at least one electromechanical drive 1, which in the embodiment shown is Fig. 12 represents a press drive.

[0140] 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 operable 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 ).

[0141] In a method for forming a workpiece 27, preferably plate-shaped, 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.

[0142] In the Figs. 14 and 15 Preferred methods for forming a workpiece 17 are now schematically illustrated. Fig. 14It can be seen that before 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 opposes the drive torque M of the electric drive source 2. The beginning of the movement phase 33 of the forming tool 28 is triggered by moving the braking device 5 into the released position and / or into a position with reduced braking torque.

[0143] In Fig. 15 It can also be seen that during a forming step the working movement 32 of the forming tool 28 is intermittent.

[0144] The individual movement phases 33 of the working movement 32 of the forming tool 28 are in Fig. 17The path traveled by the forming tool 28 during an intermittent working movement 32 is represented schematically. It is composed of the path segments traveled during the individual movement phases 33 of the intermittent working movement 32. It can also be seen here that the direction of movement of the forming tool 28 can remain unchanged in the individual movement phases 33 of an intermittent working movement 32.

[0145] Fig. 16 Finally, a variant is shown in which the drive torque M of the electrical drive source 2 is also generated intermittently in order to achieve an intermittent working movement.

[0146] 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 moves at a lower speed than in movement phase 33. Preferably, the length of each individual movement phase 33 is less than 3 seconds, more preferably less than 1.5 seconds. Preferably, the length of each phase 34 in which the forming tool 28 is stationary or moves at a lower speed than in movement phase 33 is less than 3 seconds, more preferably less than 1.5 seconds. This allows, for example, a "hammering" action of the forming tool 28 on the workpiece 27 to be achieved.

[0147] From the variant according to Fig. 15It can be seen that an intermittent working movement of the forming tool 28 is caused by an intermittent actuation of the braking device 5 between the released position and the brake position. The braking torque B acting on the rotating part 3 can be higher than the drive torque M acting on the rotating part 3 during those phases of the intermittent actuation of the braking device 5 in which the braking device 5 is in the brake position. In this case, the actuation of the braking device 5 leads to a (brief) stop of the forming tool 28.

[0148] The electric drive source 2 can also generate a drive torque M during those phases of intermittent actuation of the brake device 5 in which the brake device 5 is in the braking position. For example, the drive torque M can be kept essentially constant during a forming step with intermittent working movement 32 of the forming tool 28.

[0149] Out of Fig. 13 - as well as from the preferred embodiments described in detail later on the Figs. 1 to 9 It is evident that the electromechanical drive 1 comprises a rotating part 3 and that the braking device 5 acts on the rotating part 3. The electrical drive source 2, which may be a motor, also acts on the rotating part 3 with its drive torque M.

[0150] In the case of an electric motor, the drive source 2 can comprise a stator 2a, which is connected to the housing 13 and / or stationary relative to the housing 13, and a rotor 2b, which is connected to the rotating part 3 or arranged directly on the rotating part 3. Appropriate supply and / or control lines lead to the electrical drive source 2.

[0151] As will be described in more detail later using the example of a spindle drive, the electromechanical drive 1 can comprise a transmission mechanism, in particular a linear drive, which converts the rotation of the rotating part 3 into a linear motion of a transmission element 23, which acts directly or indirectly on the forming tool 28. The transmission element 23 can, for example, be in the form of a spindle or a rack (on which a rotating gear acts).

[0152] The braking device 5 is - as in Fig. 13preferably shown integrated in the electromechanical drive 1. The electrical drive source 2 and the braking device 5 can be housed in the same housing 13.

[0153] Fig. 13 Figure 30 also shows a control unit 30 of the forming machine 20 for controlling the electrical drive source 2 and the braking device 5. An operating mode 31 is stored in the control unit 30, which allows the electrical drive source 2 and the braking device 5 to be controlled in such a way that the procedures described above can be carried out. The interaction between the drive source 2 and the braking device 5 has already been described in detail above. The (counter-)action of the drive torque M and the braking torque B enables the advantages mentioned in the introductory description. Reference numeral list 39 radial bearing 1 electromechanical drive 40 attachment part 2 Motor 41 Lubricant channel 2a stator 42 first section of the lubricant channel 2b rotor 3 Rotating part 43 second section of the lubricant channel 4 axis of rotation 5 Braking system 44 Return channel 6 brake disc 45 Rolling elements 7 Brake element 46 pin-shaped section 8 inner area 47 Sensor device 9 Intermediate area 48 Exit point 10 Friction surface area 49 cooling fin 11 first friction surface B Braking torque 12 second friction surface M Drive torque 13 Housing 13a Housing part 13b Housing part 13c Housing part 14 first distance ring 15 second distance ring 16 Mounting interface 17 first opposite surface 18 second opposite surface 19 excerpts 20 forming machine 21 Feather 22 actuator 23 spindle 24 basic body 25 first tool carriers 26 second tool carrier 27 workpiece 28 forming tool 29 forming tool 30 Control unit 31 Operating mode 32 Work movement 33 Movement phase 34 phase 35 Spindle exit end 36 Storage 37 Bearings in the area of ​​the spindle exit end 38 axial 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), characterized in that 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).

2. The electromechanical spindle drive according to claim 1, characterised in that the at least one bearing (37) arranged in the region of the spindle outlet end (35) of the rotational part (3) is designed in the form of a radial bearing.

3. The electromechanical spindle drive according to claim 1 or 2, characterised in that 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 one of the preceding claims, characterised in that the at least one bearing (37) arranged in the region of the spindle outlet end (35) of the rotational part (3) 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 one of the preceding claims, characterised in that the stator (2a) of the motor (2) surrounds the rotational part (3) and / or that the rotor (2b) of the motor (2) comprises pole elements mounted on the outside of the rotational part (3), preferably in a removable manner.

6. The electromechanical spindle drive according to one of the preceding claims, characterised in that 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).

7. The electromechanical spindle drive according to one of the preceding claims, characterised in 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).

8. The electromechanical spindle drive according to claim 7, characterised in that 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)9. The electromechanical spindle drive according to claim 7 or 8, characterised in that 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).

10. The electromechanical spindle drive according to any one of claims 7 to 9, characterised in that a lubricant channel (41) is configured in the attachment part (40) for supplying lubricant to the interior of the rotational part (3).

11. The electromechanical spindle drive according to claim 10, characterised in that 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), and / or that 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).

12. The electromechanical spindle drive according to any one of claims 7 to 11, characterised in that 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).

13. A spindle drive component set comprising components for a plurality of electromechanical spindle drives (1) according to one of the preceding claims, characterised in that the component set has components of different types and the components have connection interfaces for connecting the components to one another, and in that 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.

14. The spindle drive component set according to claim 13, characterised in that 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.

15. 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), characterised in that the electromechanical drive (1) is a spindle drive according to one of claims 1 to 12.

16. Method for forming a preferably plate-type workpiece (27) with a forming machine (20), in particular a bending machine, characterised in that the forming machine (20) is a forming machine according to claim 15 and that the motor (2) of the electromechanical spindle drive (1) for forming the workpiece (27) is controlled by a control device (30).