Stator device, flat electric motor and method for manufacturing a stator device

Abstract

Stator device (1) for a flat electric motor (2), comprising a first stator side part (3) and a second stator side part (4) that can be arranged opposite the first stator side part (3), wherein the second stator side part (4) can be arranged relative to the first stator side part (3) such that a gap (5) for receiving a rotor (6) is formed between the first stator side part (3) and the second stator side part (4), wherein at least the first stator side part (3) has an electrically insulating support substrate (7) with an electrically conductive conductor layer (8) arranged thereon, and wherein winding-like conductor tracks (9) are formed in the conductor layer (8), wherein the stator device (1) has a stiffening device (10) for stiffening the first stator side part (3), wherein the stiffening device (10) is also designed as a magnetic return for the first stator side part (3), characterized in thatthat the stiffening device (10) has at least one cooling fin (12) facing away from the first stator side part (3).

Description

[0001] The present invention relates to a stator device for a flat electric motor, in particular for a rapid adjustment mechanism, e.g., for a seat belt tensioning device or a seat adjuster of a motor vehicle. The invention further relates to a flat electric motor with a stator device of the generic type and to a method for manufacturing a stator device of the generic type for a flat electric motor.

[0002] Due to continuously increasing traffic density and the associated rise in the risk of accidents, the safety of vehicle occupants is a crucial aspect in the development of motor vehicles. A key distinction is made between accident-preventing and accident-mitigating safety systems. Accident-preventing safety systems are designed to detect potentially dangerous driving situations and, if necessary, initiate measures to avert an accident. Within this framework, a further distinction is made between actively intervening systems and warning systems. Actively intervening systems can, for example, influence wheel torque, steering angle, or vehicle roll. In this way, wheel lockup can be prevented, braking can be initiated, or an evasive maneuver can be performed, all while taking the vehicle's center of gravity into account. For this purpose, the shock absorbers, for example, are adjusted.They are equipped with a quick-adjustment mechanism. Warning systems typically indicate a hazardous situation visually, audibly, or haptically, for example, through warning lights, tones, vibrations, or similar means. Often, actively intervening safety systems are linked to warning systems, so that the automatic intervention of an actively intervening safety system is confirmed by a warning system.

[0003] Accident-reducing safety systems, on the other hand, are designed to mitigate the impact of a dangerous driving situation or an accident on the vehicle's occupants, the surrounding environment, or the vehicle itself. Examples of accident-reducing safety systems for protecting occupants include body design, chassis components, airbags, safety glass, vehicle seats, and seat belts. Seat belts and vehicle seats are designed to hold a vehicle occupant in place during severe deceleration, such as emergency braking, a collision with an obstacle, or similar events, thereby preventing or at least reducing injuries. To improve this function, modern safety systems incorporate quick-adjustment devices, such as...Seatbelt pretensioners, seat position adjusters, shock absorber adjusters, and steering angle adjusters are used in a safety system that, in a dangerous situation, particularly during or immediately before a collision or emergency braking, releases slack to allow the occupants to participate more effectively and earlier in the vehicle's deceleration. A critical driving situation can be detected, for example, by means of appropriately designed sensors. Sensor data can be evaluated via a control unit or triggering device to activate the quick-adjusting mechanisms as needed. Alternatively, the sensors and triggering device can be designed as a purely mechanical unit.

[0004] Common quick-adjustment devices for seatbelt pretensioners or seat elements, such as seat ramps or headrests, contain an explosive charge that can be detonated in a critical driving situation, tightening the seatbelt or moving a seat element to a different position. Such quick-adjustment devices have the disadvantage that the charge is consumed after detonation and must be reloaded in a workshop. If, for example, an accident occurs between the seatbelt being tightened and the pretensioner being reloaded, the pretensioner is inoperative. The same applies, of course, to quick-adjustment seat devices. The vehicle occupant is then no longer optimally protected. An alternative design, for example, of a seatbelt pretensioner, uses an electric motor instead of an explosive charge, which can be activated in a critical driving situation to tighten the seatbelt.The same applies to seat component adjusters such as headrests or ramps. Such electric motors can usually handle rapid adjustments at intervals without any problems. However, these electric motors, which typically require a gearbox, usually have a relatively large installation space and a high weight to provide sufficient power for a rapid adjustment. This is particularly disadvantageous in areas with very limited installation space. Furthermore, a vehicle's energy consumption increases with its weight, so such electric motors result in higher energy consumption for the vehicle.

[0005] To reduce the weight of quick-adjustment devices, such as seatbelt pretensioners, flat electric motors can be used. Flat electric motors are described, for example, in documents US 2011 / 0291511 A1, US 2017 / 0353072 A1, DE 10 2005 023 493 A1, and DE 27 18 428 C2. A flat electric motor has a rotor. The rotor is rotatably mounted between two plate-shaped stator halves. These flat electric motors with laterally arranged air-core coils require less installation space compared to conventional electric motors. However, conventional flat electric motors have the disadvantage of a relatively low maximum torque. Furthermore, flat electric motors tend to burn out under high loads because they are driven with relatively high currents to generate high torque. This is especially true when the flat electric motors are subjected to regular high loads. Finally, under high stress, one stator half of a flat electric motor can bend due to the strong magnetic field. In extreme cases, the stator half and rotor can even touch, thus slowing down the rotor and damaging or destroying the flat electric motor.

[0006] It is therefore an object of the present invention to eliminate, or at least partially eliminate, the disadvantages described above in a stator device for a flat electric motor, an electric motor for a quick-adjustment device, such as a seatbelt tensioner, for a motor vehicle, and a method for manufacturing a stator device for an electric motor. In particular, it is an object of the present invention to provide a stator device, an electric motor, and a method for manufacturing a stator device for an electric motor that promote high operational reliability of an electric motor and prevent damage in a simple and cost-effective manner.

[0007] The aforementioned problem is solved by the claims. Accordingly, the problem is solved by a stator device for a flat electric motor with the features of independent claim 1, by an electric motor for a quick-adjustment device, such as a seatbelt tensioner, for a motor vehicle with the features of dependent claim 14, and by a method for manufacturing a stator device for an electric motor with the features of dependent claim 15. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings.Features and details described in connection with the stator device according to the invention naturally also apply in connection with the electric flat motor according to the invention and the method according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, mutual reference is always made or can be made.

[0008] According to a first aspect of the invention, the problem is solved by a stator device for a flat electric motor. The stator device comprises a first stator side part and a second stator side part that can be arranged opposite the first stator side part, wherein the second stator side part can be arranged relative to the first stator side part such that a gap for receiving a rotor is formed between the first and second stator side parts. At least the first stator side part has an electrically insulating substrate with an electrically conductive conductor layer arranged thereon. The conductor layer can be designed as a cover layer. Preferably, the conductor layer is arranged between the substrate and an insulating layer. Winding-like conductor tracks are formed in the conductor layer.According to the invention, the stator device has a stiffening device for stiffening the first stator side part, wherein the stiffening device is also designed as a magnetic return for the first stator side part.

[0009] The first and second stator side sections of the stator device can be arranged relative to each other such that a gap is formed between them. The gap is preferably uniform with a constant width, so that the distance between the first and second stator side sections is constant, or at least constant within a certain operating range. The gap has a width such that a rotor designed for the stator device can be positioned between the first and second stator side sections. The rotor can be positioned within the gap such that the air gap between the rotor and the first and / or second stator side sections is between 0.1 mm and 0.5 mm, particularly 0.3 mm.A surface of the first stator side section facing the second stator side section is therefore preferably flat or planar. Equally preferred is a surface of the second stator side section facing the first stator side section being flat or planar, such that the gap is uniform or at least uniform within an effective area of ​​the stator device. This has the advantage that, with a corresponding design of the rotor, the air gap between the rotor and the first stator side section or the second stator side section is also uniform.

[0010] The first stator side section comprises the electrically insulating support substrate. The support substrate can consist of a single layer or multiple layers, which are preferably interconnected. The support substrate is preferably flexible. The conductive conductor layer is arranged on the support substrate. The conductor layer is preferably flexible. Preferably, the first stator side section is flexible or at least bendable. Thus, the first stator side section is preferably designed like a flexible circuit board.

[0011] The conductor layer is designed to have winding-like conductor tracks and can be applied to one or both sides of the substrate. In this way, the conductor layer provides a magnetic coil, or at least a portion thereof. The excitation field of the flat electric motor, used to drive the rotor, can thus be generated by means of these conductor tracks. The winding-like conductor tracks are produced, for example, by etching the conductor layer. Alternatively, the winding-like conductor tracks can be produced using an additive manufacturing process. Preferably, the conductor layer is made of copper or is formed from copper, or at least is composed primarily of copper. Other embodiments are conceivable for the formation of the magnetic coils. For example, grid structures can be applied to a suitable substrate material.These grid structures can be made from various conductive materials, preferably copper, iron, steel, and aluminum. The structures can be manufactured, for example, by waterjet cutting, laser cutting, stamping, or any other cutting process.

[0012] However, other conductive materials are also conceivable for use as conductor tracks and coils; ferrous materials or aluminum in its various alloys are conceivable. The first stator side section has a large cross-section relative to its thickness. Preferably, the second stator side section also has a large cross-section relative to its thickness. Preferably, the conductor layer faces away from the stiffening device, and the support substrate faces the stiffening device. The support substrate can, for example, contact the stiffening device.

[0013] The stiffening device is designed to stiffen the first stator side section and comprises a magnetically conductive material, in particular iron, sheet metal such as ST12 or the like, or is formed from such a material. A sandwich system is also conceivable, such as a combination of readily formable steel and a soft magnetic powder composite (SMC = soft metal composite). Preferably, the stiffening device is plate-shaped or disc-shaped. More preferably, the stiffening device is adapted to an outer contour of the first stator side section or corresponds to it at least substantially. It can be provided that the stiffening device has a central recess for passing through a part of the rotor, in particular a rotor shaft. The stiffening device thus serves as a magnetic return for the first stator side section.Therefore, it is preferred that the stiffening device is arranged on a side of the first stator side facing away from the second stator side. The stiffening device is preferably connected to or held on the first stator side in such a way that bending of the first stator side by means of the stiffening device is prevented. The first stator side is thus protected against bending, warping, or shielding.

[0014] A stator device according to the invention for a flat electric motor has the advantage over conventional stator devices that the stability of the stator device, in particular of the first stator side part, is increased by the stiffening device in a simple and cost-effective manner. The thickness of the stator device is only slightly increased, so that a flat electric motor with a stator device according to the invention has a small installation space. In addition, the stiffening device has the further effect of improving the excitation field in the gap. The efficiency of the flat electric motor can thus be improved. Furthermore, the stress on the conductor tracks during operation of the flat electric motor can be reduced, so that the stator device has an improved service life.

[0015] According to a preferred embodiment of the invention, the stator device may be provided with a surface of the first stator side facing the second stator side having a flatness tolerance of 1 / 10 mm or less. It is preferred that the surface exhibits this flatness tolerance in conjunction with the stiffening device. In the operational state of the stator device, the surface faces the gap or air gap between the first and second stator side parts. Within the scope of the invention, a flatness tolerance is understood to mean that the surface is flat and deviations from an ideal flat surface are permitted within the flatness tolerance, i.e., a maximum of 1 / 10 mm. A flatness tolerance may be necessary, in particular, due to manufacturing limitations such as machine accuracy, material properties, or the like.With such a flatness tolerance, a particularly advantageous air gap can be achieved using simple and cost-effective means.

[0016] According to the invention, it is preferred that a conductor layer is arranged on both sides of the support substrate. Preferably, winding-like conductor tracks are formed in both conductor layers. In this preferred embodiment, it is further preferred that additional electrical insulation, e.g., a film, a lacquer layer, or the like, is arranged between the conductor layer and the stiffening device to prevent a short circuit of the conductor tracks by the stiffening device. Such a first stator side part has the advantage that the performance of the flat electric motor can be improved using simple means and in a cost-effective manner.

[0017] Preferably, the first stator side section has several carrier substrates, each with at least one conductor layer, arranged one above the other. The carrier substrates are thus stacked on top of each other, with a first conductor layer preferably arranged on a first carrier substrate contacting an adjacent second carrier substrate. Alternatively, it can also be provided that the first conductor layer arranged on the first carrier substrate contacting a second conductor layer arranged on the adjacent second carrier substrate. In this case, the first conductor layer and the second conductor layer are preferably configured such that they form one or more common conductor tracks. Here, it is envisaged to design the coil arrangement of the second carrier substrate with conductor layer as a mirror image of the first carrier substrate with coil conductor layers on both sides.Alternatively, electrical insulation, such as a film, a lacquer layer, or the like, can be arranged between immediately adjacent conductor layers. Preferably, at least one support substrate has a conductor layer on both sides. More preferably, another support substrate has a conductor layer on only one side. Such a first stator side part has the advantage that the performance of the flat electric motor can be improved simply and cost-effectively.

[0018] In a particularly preferred embodiment of the invention, a stator device may be provided in such a way that the stiffening device is fixed to the first stator side part by means of an adhesive layer, in particular an electrically insulating one. A molecular bond between the stiffening device and the first stator side part can be achieved by means of the adhesive layer. Preferably, the adhesive layer has sufficient heat resistance to ensure that the stiffening device remains fixed to the first stator side part at the intended operating and storage temperatures of the electric flat motor. The stiffening device and the first stator side part can be connected to each other simply, cost-effectively, and preferably permanently by means of an adhesive layer, thus preventing the first stator side part from bending away from the stiffening device during operation of the electric flat motor.

[0019] Preferably, the stiffening device has at least one cooling fin facing away from the first stator side section. More preferably, the stiffening device has several such cooling fins, which are particularly evenly distributed across the stiffening device. The cooling fins are preferably non-magnetizable, thus preventing any interaction between the excitation field and the cooling fins. Alternatively, the cooling fins can be magnetizable. In this case, it is preferred that the cooling fins are designed and arranged in such a way as to further enhance the stator feedback effect. Cooling fins have the advantage that the risk of overheating of the first stator side section can be reduced. Heat can thus be dissipated from the first stator side section via the stiffening device and the cooling fins in a simple and cost-effective manner.

[0020] According to a preferred embodiment of the invention, the support substrate and / or the stiffening device comprises a prepreg. A prepreg is a textile fiber-matrix component comprising reinforcing fibers embedded in a matrix material, in particular a resin. In the stiffening device, magnetically conductive elements can be embedded in or laminated with the prepreg. A prepreg offers the advantage that, depending on the chosen matrix material, a specific degree of flexibility or stiffness can be achieved. Furthermore, prepregs are easy to process, particularly moldable, and readily available at low cost. Additionally, a prepreg has a relatively low density and is therefore particularly suitable for reducing the weight of the flat electric motor.Finally, prepregs can be cured in an advantageous way, ensuring good dimensional stability even under high mechanical loads.

[0021] The second stator side part preferably comprises an electrically insulating support substrate with an electrically conductive conductor layer arranged thereon, wherein winding-like conductor tracks are formed in the conductor layer. Furthermore, the stator device includes a stiffening device for stiffening the second stator side part, wherein the stiffening device is designed as a magnetic return for the second stator side part. It is preferred that the second stator side part be flexible. It is particularly preferred that the second stator side part has the same characteristics as described above with respect to the first stator side part. According to the invention, it is preferred that the first stator side part and the second stator side part are identical or at least substantially identical.Preferably, the stiffening device arranged on the first stator side section corresponds at least substantially to the stiffening device arranged on the second stator side section. A stator device designed in this way has the advantage that the overall thickness of the flat electric motor can be reduced simply and cost-effectively while maintaining or improving performance.

[0022] Preferably, the stiffening devices each have at least one mounting connection for connecting them. The stiffening device arranged on the first stator side section can be connected to the stiffening device arranged on the second stator side section by means of the mounting connection, thus fixing the relative position of the first and second stator side sections. Preferably, the stiffening devices each have at least two, and more preferably three or four, mounting connections, which are spaced as far apart as possible to ensure the relative positional fixation of the first and second stator side sections. Such mounting connections have the advantage that the relative position of the first and second stator side sections can be fixed simply and cost-effectively.A defined gap between the first stator side part and the second stator side part can therefore be guaranteed.

[0023] Preferably, the stiffening device has a receiving section for arranging a bearing or a raceway for rolling elements or bearing shells for rotatably supporting the rotor of the electric flat motor. According to the invention, if there are several stiffening devices, each stiffening device may have such a receiving section or raceway. It may also be provided that a stiffening device has several, in particular two, receiving sections or several, in particular two, raceways. A receiving section is preferably formed according to a central recess of a hollow cylinder. A raceway preferably has a concave cross-section to prevent the rolling elements from slipping. Furthermore, lateral limits may be provided on a receiving section and / or a raceway to prevent lateral slippage of the bearing or the rolling elements.According to the invention, the bearing can be designed, in particular, as a rolling bearing, such as a ball bearing, roller bearing, spherical bearing, needle bearing, or the like. Preferably, the bearing is designed as a precision bearing. The rolling element is preferably designed as a ball, cylinder, barrel, needle, or the like. Alternatively, a plain bearing can also be used. Such a stiffening device has the advantage that the rotor can be mounted on the stator assembly using simple and cost-effective means. Due to the high strength of the stiffening device, unintentional relative pivoting and linear movement of the rotor relative to the stator assembly can be prevented simply and cost-effectively.

[0024] It is preferred that the first stator side part and the second stator side part share a common support substrate. The support substrate is preferably designed similarly to, or identically with, that of the first stator side part as with that of the second stator side part. Furthermore, the conductor layer in the region of the first stator side part is preferably designed similarly to, or identically with, that of the second stator side part. To facilitate the relative arrangement of the first and second stator side parts while maintaining a constant gap, the support substrate preferably has a curved section. Preferably, the support substrate is folded or bent by 180° in the curved section. A common support substrate offers the advantage of simplifying the production of the first and second stator side parts using simple means and in a cost-effective manner.

[0025] According to a preferred embodiment of the invention, a stator device may be provided with a sensor device for determining the rotational speed and / or angular position of the rotor on the first and / or second stator side section. The sensor device preferably includes a sensor for detecting markings arranged on the rotor. This sensor may be, for example, inductive, capacitive, magnetic, or optical. The sensor device is preferably arranged in the area of ​​a bearing seat of the first or second stator side section. Alternatively, the sensor device may also be arranged on the circumference of the rotor disk. By means of a sensor device, the angular position and / or rotational speed of the rotor relative to the stator device can advantageously be determined in a simple and cost-effective manner.

[0026] Preferably, the first and second stator side panels are connected to each other via a folded section. It is also conceivable that the folded section provides an electrically conductive connection between the first and second stator side panels. This allows for the electronic components to be distributed between the first and second stator side panels. In this way, for example, power sections can be spatially separated from the control sections of the motor electronics. A folded section has a bend or fold and can be manufactured simply and cost-effectively. Furthermore, a folded section is well-suited for connecting the first and second stator side panels, for example, via a connecting shaft supported by the folded section.Finally, a relative position of the first stator side part to the second stator side part can be determined by means of a folded section, thus facilitating the alignment of the first stator side part to the second stator side part.

[0027] According to a second aspect of the invention, the problem is solved by a flat electric motor for a quick-adjustment device, such as a seatbelt tensioner, for a motor vehicle. The flat electric motor has a stator assembly and a rotor that can be rotated by means of the stator assembly. According to the invention, the stator assembly is designed as a stator assembly according to the invention. The rotor preferably has permanent magnets so that the rotor can be set into rotation by means of a magnetic excitation field generated by the stator assembly.

[0028] The described flat electric motor offers all the advantages already described for a stator assembly according to the first aspect of the invention. Accordingly, the flat electric motor according to the invention has the advantage over conventional flat electric motors that the stability of the stator assembly, in particular of the first stator side section, is increased by the stiffening device in a simple and cost-effective manner. This only slightly increases the thickness of the stator assembly, so that the flat electric motor with the stator assembly according to the invention has a small installation space. In addition, the stiffening device has the further effect of improving the excitation field in the gap. The efficiency of the flat electric motor is thus improved.Furthermore, this reduces the stress on the conductor tracks during operation of the electric flat motor, thus improving the lifespan of the electric flat motor.

[0029] According to a third aspect of the invention, the problem is solved by a method for manufacturing a stator device for a flat electric motor. The method comprises the following steps: - Providing a first stator side part and a second stator side part, wherein at least the first stator side part has an electrically insulating carrier substrate with an electrically conductive conductor layer arranged thereon, wherein winding-like conductor tracks are formed in the conductor layer, - Providing a stiffening device for stiffening the first stator side part, wherein the stiffening device is designed as a magnetic return for the first stator side part, - Connecting the first stator side part to the stiffening device using an adhesive layer and / or another joining technique, and - relative arrangement of the first stator side part with the second stator side part such that a gap with constant gap width is formed between the first stator side part and the second stator side part, and that the stiffening device arranged on the first stator side part is turned away from the second stator side part.

[0030] The first stator side section comprises the electrically insulating support substrate. The support substrate can consist of a single layer or multiple layers, which are preferably bonded together. The support substrate is preferably flexible. The conductive conductor layer is arranged on the support substrate. The conductor layer is preferably flexible. Preferably, the first stator side section is flexible or at least bendable. Thus, the first stator side section is preferably designed like a flexible circuit board. Preferably, the second stator side section is designed like the first stator side section.

[0031] The conductor layer is designed to have winding-like conductive tracks. In this way, a magnetic coil, or at least a portion thereof, is provided by means of the conductor layer. The excitation field of the flat electric motor for driving the rotor can thus be generated by means of these conductive tracks. The winding-like conductive tracks are produced, for example, by etching the conductor layer. Alternatively, the winding-like conductive tracks can be produced using an additive manufacturing process. Preferably, the conductor layer is made of copper, or is formed of copper, or at least is formed substantially of copper. Alternatively, other conductive materials are conceivable. The first stator side section has a large cross-section relative to its thickness. Preferably, the second stator side section also has a large cross-section relative to its thickness.Preferably, the conductor layer faces away from the stiffening device and the support substrate faces the stiffening device. The support substrate can, for example, contact the stiffening device.

[0032] The stiffening device is designed to stiffen the first stator side section and comprises a magnetically conductive material, in particular iron, sheet metal such as ST12 or the like, or is formed from such a material. A sandwich system is also conceivable, such as a combination of readily formable steel and a soft magnetic powder composite (SMC = soft metal composite). Preferably, the stiffening device is plate-shaped or disc-shaped. More preferably, the stiffening device is adapted to an outer contour of the first stator side section or corresponds to it at least substantially. It can be provided that the stiffening device has a central recess for passing through a part of the rotor, in particular a rotor shaft. The stiffening device thus serves as a magnetic return for the first stator side section.Therefore, it is preferred that the stiffening device is arranged on a side of the first stator side facing away from the second stator side. The stiffening device is preferably connected to or held against the first stator side in such a way that bending of the first stator side by means of the stiffening device is prevented. The first stator side is thus protected against bending.

[0033] The first stator side section is connected to the stiffening device by means of an adhesive layer and / or another joining technique. Preferably, the second stator side section is also connected to a stiffening device by means of an adhesive layer and / or another joining technique. The adhesive layer is preferably designed as an electrical insulator. A molecular bond between the stiffening device and the first stator side section can be achieved by means of the adhesive layer. Preferably, the adhesive layer has sufficient heat resistance to ensure that the stiffening device is fixed to the first stator side section at the intended operating temperature of the flat electric motor. The connection is also preferably made by a pressing process.

[0034] The first and second stator side sections of the stator device are arranged relative to each other such that a gap is formed between them. This gap is uniform with a constant width, ensuring that the distance between the first and second stator side sections is constant, or at least constant within a certain operating range. The gap is wide enough to accommodate a rotor designed for the stator device between the first and second stator side sections. The rotor is positioned within the gap such that the air gap between the rotor and the first and / or second stator side sections is between 0.1 mm and 0.5 mm, particularly 0.3 mm. A [missing information - likely a specific component or element] facing the second stator side section is also present.The surface of the first stator side section facing the rotor is therefore preferably flat. Equally preferably, a surface of the second stator side section facing the first stator side section is also flat, so that the gap is uniform or at least uniform within a functional area of ​​the stator device. This has the advantage that, with a corresponding rotor design, the air gap between the rotor and the first stator side section or the second stator side section is also uniform.

[0035] The method according to the invention offers all the advantages already described for a stator device according to the first aspect of the invention and for an electric flat motor according to the second aspect of the invention. Accordingly, a method according to the invention for manufacturing a stator device for an electric flat motor has the advantage over conventional methods that a stator device can be manufactured using simple means and in a cost-effective manner, the stability of which, in particular of the first stator side part, is increased by the stiffening device. The thickness of the stator device is only slightly increased, so that an electric flat motor with the stator device according to the invention has a small installation space. In addition, the use of the stiffening device has the further effect of improving the excitation field in the gap. The efficiency of an electric flat motor is thus improved.Furthermore, this reduces the stress on the conductor tracks during operation of the electric flat motor, so that a stator device produced using the inventive method has an improved service life.

[0036] In a method according to the invention, a plate-shaped spacer can be arranged between the first and second stator side parts for relative positioning and removed again after the relative positioning. The spacer can, for example, be arranged between the first stator side part and the rotor or between the second stator side part and the rotor. The spacer preferably has sufficient dimensional stability to prevent compression during a pressing operation. This ensures that the gap is formed uniformly with a constant width. The spacers, which can be horseshoe-shaped, are preferably designed in such a way as to accommodate the springback of the stator side parts after the riveting or fixing of the stiffening elements.

[0037] Preferably, the relative arrangement of the first stator side part with the second stator side part is achieved by folding. It is preferred that the first stator side part and the second stator side part share a common support substrate, which is bent or folded such that the first stator side part and the second stator side part are arranged relative to each other with a constant gap. Alternatively, a common hinge and / or a fold between the support substrates of the first stator side part and the second stator side part can be provided for this purpose. Folding has the advantage of simplifying the manufacture of the stator assembly. Furthermore, the folded circuit board has the advantage that the electronic components for controlling and regulating the machine are arranged on it, and the plug connection is also provided.Thus, in one section of the circuit board, the conductive traces and mounts for the electronic components and the two coil assemblies are produced on the substrate. The so-called placement of the electronic components onto the circuit board using the pick-and-place machine is combined with the application of the stiffening elements, and therefore preferably takes place in a single operation.

[0038] Preferably, a calibration process is performed, whereby the flatness of the first stator side plate and / or the parallelism between the first and second stator side plates are calibrated. Calibration enables the production of a stator assembly with particularly high dimensional accuracy. In this way, the air gap between the rotor and the first or second stator side plate can be minimized, thus reducing the installation space required for the flat electric motor.

[0039] Preferably, the stiffening device is provided as a sandwich component, wherein the sandwich component comprises an iron-containing pressed substrate. Such a pressed substrate for providing a sandwich component exhibits high stiffness and offers advantageous electrical conductivity.

[0040] It is preferred that the conductor tracks and mounting positions, in particular mounting positions, especially mounting holes, for receiving the electronic components are produced simultaneously with the coil assemblies on a circuit board in a single process step. Preferably, conductor tracks and / or mounting positions and / or the coil assemblies are produced on both sides of the circuit board. In this way, manufacturing processes can be accelerated and manufacturing costs reduced.

[0041] A stator device according to the invention for a flat electric motor, an electric flat motor according to the invention for a quick-adjustment device, such as a seatbelt tensioner, for a motor vehicle, and a method according to the invention for manufacturing a stator device for an electric flat motor are explained in more detail below with reference to the drawings. The drawings schematically show: Fig. 1 in a sectional view a preferred embodiment of an electric flat motor according to the invention, Fig. 2 in a top view a preferred embodiment of a stator device according to the invention, Fig. 3 in a sectional view a preferred first embodiment of a first stator side part of a stator device according to the invention, Fig. 4 in a sectional view a preferred second embodiment of a first stator side part of a stator device according to the invention, Fig. 5 in a perspective view another preferred embodiment of an electric flat motor according to the invention, Fig. 6 in a perspective view a part of a stator device according to the invention, and Fig. 7 in a flowchart a preferred embodiment of a method according to the invention.

[0042] Elements with the same function and mode of operation are in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 each with the same reference numerals.

[0043] In Fig. Figure 1 shows a schematic sectional view of a preferred embodiment of a flat electric motor 2 according to the invention. The flat electric motor 2 has a stator assembly 1 and a rotor 6 rotatably mounted on the stator assembly 1, with permanent magnets 18. The stator assembly 1 has a first stator side part 3 and a second stator side part 4, which are arranged relative to each other forming a constant gap 5. The rotor 6 is arranged between the first stator side part 3 and the second stator side part 4. An air gap 17 is formed between the first stator side part 3 and the rotor 6, and between the second stator side part 4 and the rotor 6.

[0044] The first stator side part 3 has an electrically insulating support substrate 7 with an electrically conductive conductor layer 8 facing the second stator side part 4. Winding-like conductor tracks 9 are formed in the conductor layer 8. To stiffen the first stator side part 3, a stiffening device 10, designed as a magnetic return for the first stator side part 3, is arranged on the support substrate 7 of the first stator side part 3 and is connected to the support substrate 7 of the first stator side part 3 via an adhesive layer 11, preferably electrically insulating. On a side facing away from the first stator side part 3, the stiffening device 10 has several cooling fins 12, which are preferably non-magnetic.

[0045] In this embodiment, the second stator side part 4 is designed in accordance with the first stator side part 3. Accordingly, the second stator side part 4 has an electrically insulating support substrate 7 with an electrically conductive conductor layer 8 facing the first stator side part 3. Winding-like conductor tracks 9 are formed in the conductor layer 8. To stiffen the second stator side part 4, a stiffening device 10, designed as a magnetic return for the second stator side part 4, is arranged on the support substrate 7 of the second stator side part 4 and is connected to the support substrate 7 of the second stator side part 4 via an adhesive layer 11, preferably electrically insulating. On a side facing away from the second stator side part 4, the stiffening device 10 has several cooling fins 12, which are preferably non-magnetic.The stiffening devices 10 each have two mounting connections 13, wherein the mounting connections 13 of the stiffening device 10 of the first stator side part 3 are each fixed to a mounting connection 13 of the stiffening device 10 of the second stator side part 4 via a fastening means 16. In this way, relative movement of the first stator side part 3 to the second stator side part 4 is prevented. In the stiffening device 10 arranged on the first stator side part 3, a receiving section 14 is formed for receiving a precision bearing for the rotatable bearing of the rotor 6 relative to the stator device 1. A sensor device 15 for detecting a rotational speed and / or an angular position of the rotor 6 is arranged on the receiving section 14.

[0046] In Fig. Figure 2 shows a preferred embodiment of a stator device 1 according to the invention, schematically depicted in a top view. In this representation, the first stator side part 3 with the annular stiffening device 10 fixed to it is visible. The second stator side part 4 (see Figure 2) is shown in Figure 3. Fig. 1) with the ring-shaped stiffening device 10 fixed to it is concealed. The first stator side part 3 and the second stator side part 4 have a central passage 19 for arranging a rotor 6 (not shown) (see figure). Fig. 1). In the embodiment 19, a receiving section 14 is formed for receiving a bearing (not shown) for the rotatable support of the rotor 6. In the area of ​​the receiving section 14, a sensor device 15 is arranged for detecting a rotational speed and / or an angular position of the rotor 6. The first stator side part 3 and the second stator side part 4 have a common support substrate 7, which is folded by 180° in a folded section 20, so that the first stator side part 3 is arranged parallel to the second stator side part 4. Furthermore, the first stator side part 3 has a mounting connection 13 to which a fastening element 16, designed as a flat strip, is attached. This fastening element is also attached to a mounting connection 13 (not shown) of the second stator side part 4 and thus fixes a relative position of the first stator side part 3 to the second stator side part 4.

[0047] In Fig. Figure 3 is a preferred first embodiment of a first stator side part 3 of a stator device 1 according to the invention, shown schematically in a sectional view. The first stator side part 3 has an electrically insulating support substrate 7 on which a conductor layer 8 is arranged on both sides. Winding-like conductor tracks 9 are formed in each of the conductor layers. To stiffen the first stator side part 3, a stiffening device 10, designed as a magnetic return for the first stator side part 3, is arranged on a conductor layer 8 of the first stator side part 3 and is connected to the conductor layer 8 of the first stator side part 3 via an adhesive layer 11, preferably electrically insulating.

[0048] In Fig. Figure 4 shows a preferred second embodiment of a first stator side part 3 of a stator device 1 according to the invention, schematically depicted in a sectional view. The first stator side part 3 has an electrically insulating support substrate 7 on which a conductor layer 8 is arranged. On the conductor layer 8, a further support substrate 7 with a conductor layer 8 is arranged such that a support substrate 7 is positioned between two conductor layers 8. Winding-like conductor tracks 9 are formed in each of the conductor layers. To stiffen the first stator side part 3, a stiffening device 10, designed as a magnetic return for the first stator side part 3, is arranged on a support substrate 7 of the first stator side part 3 and is connected to the support substrate 7 of the first stator side part 3 via an adhesive layer 11, preferably electrically insulating.

[0049] Fig. Figure 5 schematically shows a further preferred embodiment of a flat electric motor 2 according to the invention in a perspective view. The flat electric motor 2 has the stator assembly 1 with the first stator side part 3 and the second stator side part 4, on each of which the stiffening device 10, designed as a stator backplate, is arranged. The conductor tracks 9 of the stator assembly are clearly visible in this illustration. The first stator side part 3 is fixed in position to the second stator side part 4 by riveting. Alternatively, rivets, screws, or clips can also be used for relative positional fixation instead of riveting.

[0050] In Fig. Figure 6 schematically depicts a part of a stator device 1 according to the invention in a perspective view and in a partially unfolded state. In this illustration, the first stator side part 3 and the second stator side part 4 are shown without a stiffening device 10. Conductive traces 9 are formed on both sides of the first stator side part 3 and the second stator side part 4. The folding between the first stator side part 3 and the second stator side part 4 is achieved via their end faces. According to the invention, folding via the longitudinal sides is also conceivable.

[0051] In Fig.Figure 7 schematically illustrates a preferred embodiment of a method according to the invention in a flowchart. In a first process step 100, a first stator side part 3 and a second stator side part 4 are provided. At least the first stator side part 3 has an electrically insulating support substrate 7 with an electrically conductive conductor layer 8 arranged thereon. Preferably, the second stator side part 4 also has an electrically insulating support substrate 7 with an electrically conductive conductor layer 8 arranged thereon. Winding-like conductor tracks 9 are formed in the conductor layer 8. In a second process step 200, a stiffening device 10 is provided for stiffening the first stator side part 3. The stiffening device 10 is designed as a magnetic return for the first stator side part 3.Preferably, a further stiffening device 10 is provided for stiffening the second stator side part 4. This stiffening device 10 is designed as a magnetic return for the second stator side part 4. In a third process step 300, the first stator side part 3 is connected to the stiffening device 10 by means of an adhesive layer 11 and preferably pressed together. Preferably, in the third process step 300, the second stator side part 4 is also connected to the stiffening device 10 by means of an adhesive layer 11 and preferably pressed together. In a fourth process step 400, the first stator side part 3 and the second stator side part 4 are arranged relative to each other such that a gap 5 with a constant gap width is formed between the first stator side part 3 and the second stator side part 4.The stiffening device 10 arranged on the first stator side part 3 faces away from the second stator side part 4. Preferably, the stiffening device 10 arranged on the second stator side part 4 faces away from the first stator side part 3. Reference symbol list 1 Stator device 2 electric flat motors 3 first stator side part 4 second stator side part 5 columns 6 runners 7 Carrier substrate 8 conductor layer 9 conductor track 10 Stiffening device 11 Adhesive layer 12 cooling fins 13 Mounting connection 14 Recording section 15 Sensor device 16 Fasteners 17 air gap 18 permanent magnets 19 Implementation 20 folding section 100 first procedural step 200 second procedural step 300 third procedural step 400 fourth process step

Claims

[1] Stator device (1) for a flat electric motor (2), comprising a first stator side part (3) and a second stator side part (4) which can be arranged opposite the first stator side part (3), wherein the second stator side part (4) can be arranged relative to the first stator side part (3) such that a gap (5) for receiving a rotor (6) is formed between the first stator side part (3) and the second stator side part (4), wherein at least the first stator side part (3) has an electrically insulating support substrate (7) with an electrically conductive conductor layer (8) arranged thereon, and wherein winding-like conductor tracks (9) are formed in the conductor layer (8), wherein the stator device (1) has a stiffening device (10) for stiffening the first stator side part (3), wherein the stiffening device (10) is also designed as a magnetic return for the first stator side part (3). characterized bythat the stiffening device (10) has at least one cooling fin (12) facing away from the first stator side part (3). [2] Stator device (1) according to claim 1, characterized by , that a surface of the first stator side part (3) facing the second stator side part (4) has a flatness tolerance of 1 / 10 mm or less. [3] Stator device (1) according to at least one of the preceding claims, characterized by , that a conductor layer (8) is arranged on both sides of the support substrate (7). [4] Stator device (1) according to any one of the preceding claims, characterized by , that the first stator side part (3) has several carrier substrates (7) each with at least one conductor layer (8), wherein the carrier substrates (7) are arranged one above the other. [5] Stator device (1) according to at least one of the preceding claims, characterized bythat the stiffening device (10) is fixed to the first stator side part (3) by means of an adhesive layer (11), in particular an electrically insulating one. [6] Stator device (1) according to at least one of the preceding claims, characterized by , that the support substrate (7) and / or the stiffening device (10) comprises a prepreg. [7] Stator device (1) according to at least one of the preceding claims, characterized by , that the second stator side part (4) has an electrically insulating carrier substrate (7) with an electrically conductive conductor layer (8) arranged thereon, wherein winding-like conductor tracks (9) are formed in the conductor layer (8), wherein the stator device (1) has a stiffening device (10) for stiffening the second stator side part (4), and wherein the stiffening device (10) is designed as a magnetic return for the second stator side part (4). [8] Stator device (1) according to claim 7, characterized by that the stiffening devices (10) each have at least one fastening connection (13) for connecting the stiffening devices (10). [9] Stator device (1) according to at least one of the preceding claims, characterized by , that the stiffening device (10) has a receiving section (14) for arranging a bearing or a raceway for rolling elements for rotatably supporting the rotor (6) of the electric flat motor (2). [10] Stator device (1) according to at least one of the preceding claims, characterized by , that the first stator side part (3) and the second stator side part (4) have a common support substrate (7). [11] Stator device (1) according to at least one of the preceding claims, characterized by, that a sensor device (15) for determining a rotational speed and / or a rotational angle position of the rotor (6) is arranged on the first stator side part (3) and / or second stator side part (4). [12] Stator device (1) according to at least one of the preceding claims, characterized by , that the first stator side part (3) and the second stator side part (4) are connected to each other via at least one folded section (20). [13] Flat electric motor (2) for a quick-adjustment device for a motor vehicle, comprising a stator device (1) and a rotor (6) rotatable by means of the stator device (1), characterized by , that the stator device (1) is designed as a stator device (1) according to at least one of the preceding claims. [14] Method for manufacturing a stator device (1) for a flat electric motor (2), comprising the following steps: - Providing a first stator side part (3) and a second stator side part (4), wherein at least the first stator side part (3) has an electrically insulating carrier substrate (7) with an electrically conductive conductor layer (8) arranged thereon, wherein winding-like conductor tracks (9) are formed in the conductor layer (8), - Providing a stiffening device (10) for stiffening the first stator side part (3), wherein the stiffening device (10) is designed as a magnetic return for the first stator side part (3), - Connecting the first stator side part (3) to the stiffening device (10) by means of an adhesive layer (11) and / or another joining technique, - relative arrangement of the first stator side part (3) with the second stator side part (4) such that a gap (5) with a constant gap width is formed between the first stator side part (3) and the second stator side part (4), and that the stiffening device (10) arranged on the first stator side part (3) faces away from the second stator side part (4), and - Providing at least one cooling fin (12) facing away from the first stator side part (3) on the stiffening device (10). [15] Method according to claim 14, characterized by , that for the relative arrangement a plate-shaped spacer body is arranged between the first stator side part (3) and the second stator side part (4) and is removed again after the relative arrangement. [16] Method according to claim 14 or 15, characterized by , that the relative arrangement of the first stator side part (3) with the second stator side part (4) is achieved by folding. [17] Method according to claim 14 or 15, characterized by , that a calibration is carried out, wherein during the calibration a flatness of the first stator side part (3) and / or a parallelism between the first stator side part (3) and the second stator side part (4) is calibrated. [18] Method according to claims 14 to 17, characterized by that the stiffening device is provided as a sandwich component, wherein the sandwich component has an iron-containing press substrate. [19] Method according to claims 14 to 18, characterized by , that the conductor tracks and mounting positions of the electronic components are manufactured simultaneously with the coil arrangements on a circuit board in a common process step.

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