Electric drive component and method and production device for production thereof, as well as electric drive having such an electric drive component

Abstract

The invention relates to a method for producing an electric drive component 20 having at least two bearing devices 21, 25 and comprising at least the following steps: providing a first attachment element 31; arranging a first bearing device 21 on the first attachment element 31; arranging a second bearing device 25 on the first attachment element 31; introducing a preloading force Fv onto at least one of the two bearing devices 21, 25, wherein the introduced preloading force Fv causes a force to be applied to the two bearing devices 21, 25; and at least one of the two bearing devices 21, 25 is welded to at least one second attachment element 36 in at least one welding region B1, B2, B3 when the preloading force Fv is applied, as a result of which at least one welded connection S1, S2, S3 is created between an attachment element material of the second attachment element 36 and a bearing device material of one of the two bearing devices 21, 25. The invention also includes an electric drive component, a production device for producing an electric drive component and an electric drive.

Description

[0001] Electric drive component and method and manufacturing device for its production, as well as electric drive with such an electric drive component

[0002] The present invention relates to a method for producing an electric drive component according to the preamble of patent claim 1, an electric drive component according to the preamble of patent claim 11, a manufacturing device according to patent claim 16 and an electric drive according to the preamble of patent claim 17.

[0003] Technological background

[0004] Electrical drive components, such as motors or gearboxes, comprise a shaft with bearings. The bearings connect a rotor to a stator. Usually, and especially to absorb larger radial forces, the rotor is supported relative to the stator by two bearings. The bearings are attached to the rotor and stator in such a way that the axial play between the rotor and stator is minimized.

[0005] DE 10 2005 058078 A1 is known from the prior art. It discloses an electric motor with a bearing system for supporting a shaft, which includes a rolling bearing in the form of a plain bearing. The rolling element of the rolling bearing has a groove in which a spring element is arranged. When the electric motor is assembled, the spring element is preloaded in the radial direction, ensuring play-free support of a shaft of the electric motor in the radial direction by means of the rolling bearing. A similar electric motor is known from DE 10 2019 001273 A1.

[0006] The disadvantage of the known solution is that the spring element itself has mass and thus causes vibrations when the electric motor is running, reducing the motor's performance. Furthermore, vibrations or impacts on the electric motor can overload the spring element and cause it to reach its end stop. This occurs particularly with a spring element with low spring tension. A spring element with high spring tension can prevent this. However, this heavily preloads the bearing, resulting in high friction in the bearing during normal operation.

[0007] Furthermore, WO 2021 077373 A1 is known from the prior art. It discloses an electric motor comprising a stator, a rotor with a shaft, and a bearing assembly. The bearing assembly includes a ball bearing and an oil bearing. The ball bearing and the oil bearing are housed inside the stator, and the rotating shaft penetrates a base of the stator. The shaft and the ball bearing can be glued, welded, snapped, screwed, etc., together. Similar electric motors can be found in DE 10 2013 100741 A1 and CN 213027571 U.

[0008] The disadvantage of the known solutions is that the ball bearing develops natural vibrations axially relative to the shaft during operation of the electric motor, thus reducing the performance of the electric motor. According to the well-known Schaeffler diagram from the literature, such materials are not suitable for welding due to the high carbon content in the ball bearing steel. For example, there is an increased risk of hot cracks in the welded joints.

[0009] Furthermore, DE 102013 227056 A1 is known from the prior art. It discloses a housing for an electrical machine comprising a housing blank extending concentrically around an axis. An overmolding is formed in the housing blank, extending transversely to the axis, and into which a bearing is molded centrally. A stamped sheet metal with a first leg is welded to the bearing to hold the bearing centrally in the housing blank, allowing the bearing to be subsequently overmolding.

[0010] The disadvantage of the known solution is that the bearing, with the aid of the stamped sheet, serves only as an auxiliary fastening means for the subsequent overmolding and thus contributes nothing to the preload or fastening in the housing blank during operation of the electric motor. Description of the invention

[0011] One object of the invention is to avoid at least one of the disadvantages of the prior art. In particular, an improved method for manufacturing an electric drive component is to be created, so that the electric drive component comprises fewer or simpler, standardized components and has improved performance. The aim is to create an improved electric drive component and an improved electric drive that are lighter and / or have improved performance and a longer service life. The aim is to create a manufacturing device with which an improved electric drive component can be manufactured.

[0012] This problem is solved by the features of the independent patent claims. Advantageous further developments are set forth in the figures and in the dependent patent claims.

[0013] A method according to the invention for producing an electric drive component with at least two bearing devices comprises at least the following steps: a) providing a first fastening element; b) arranging a first bearing device on the first fastening element; c) arranging a second bearing device on the first fastening element; d) introducing a preload force onto at least one of the two bearing devices, wherein e) the introduced preload force causes a force to act on both bearing devices; and f) at least one of the two bearing devices is welded to at least one second fastening element in at least one welding area while the preload force is acting, thereby creating at least one welded connection between a fastening element material of the second fastening element and a bearing device material of one of the two bearing devices.

[0014] The preload prevents axial vibration of the bearing devices and the components arranged on the bearing device in the electric drive component during operation, so that the electric drive component is free of play. The welded connection creates a material-to-material connection without additional material or additional element between one of the two bearing devices and the second fastening element. During welding, the material of the fastening element and the material of the bearing device are heated to such an extent that they melt and liquefy. In the molten state, the molten material of the fastening element mixes with the molten material of the bearing device to form a more or less homogeneous melt. When less or no further heat energy is supplied by welding, the molten material cools and solidifies again.The solidification of the melt creates a strong bond between the fastener material and the bearing material.

[0015] The welded joint is arranged in a welded area, whereby the welded joint does not have to encompass the entire welded area. The welded area runs along a contact surface between the fastener material of the second fastener and the bearing device material of one of the two bearing devices, in which the creation of a welded joint is possible.

[0016] The welded joint thus ensures that the second fastening element and at least one of the two bearing assemblies in the electric drive component are mechanically connected to one another. The welded joint is created after a preload is applied to at least one of the two bearing assemblies, so that after the welding process, the two bearing assemblies are permanently preloaded against one another. This eliminates the need for spring elements for applying preload or axial ring locks, and prevents axial natural vibrations during operation of the electric drive component. This makes it possible to produce a lightweight, high-performance electric drive component with few components. The electric drive component can be designed as a motor and / or a gear unit. In particular, in an external rotor motor, the moving components have a high dead weight relative to the overall structure of the external rotor motor.The preload on the bearings protects the electric motor and bearings from axial vibration, while simultaneously reducing the weight of the moving components due to the elimination of spring elements or axial ring locks. The electric drive component is more robust overall and remains operationally stable even under external forces, such as impacts. The process described above can involve fewer manufacturing steps than the prior art processes for comparable electric drive components. The process simplifies the production of an electric drive component, allowing the use of standard components, and is therefore more cost-effective.

[0017] In particular, the at least two bearing assemblies are rolling bearing assemblies to which a preload force can be easily introduced. Applying a low preload force prevents vibrations or impacts between the rolling elements and the bearing shells, thus improving their smooth running or service life. In this case, rolling bearing assemblies include, in particular, ball bearing assemblies, roller bearing assemblies, cross-bearing assemblies, and needle bearing assemblies. The preload in the electric drive component causes the balls, rollers, or needles to rest against the outer ring of the bearing assemblies, thus preventing axial movement in the bearing assemblies and thus improving the smooth running of the bearing assemblies. Axial stability of the bearing assemblies increases the performance and service life of the electric drive component during operation.

[0018] Preloading can reduce the axial play of the electric drive component. By reducing the axial play, for example, the axial end of the electric drive component can be directly detected by a magnetic or optical encoder, and the position or speed of the rotor can be determined.

[0019] Preferably, at least one of the two bearing devices is welded to the second fastening element in a further welding area when a preload force is applied, thereby creating at least one further welded connection between a fastening element material of the second fastening element and a bearing device material of one of the two bearing devices. Particularly with an increased preload force, a further welded connection can increase the reliability of the connection between the bearing device and the second fastening element. This ensures increased stability in the electric drive component under load. Failure of the welded connections can be detected, for example, by uneven running or fluctuating drive currents in the electric drive component.

[0020] In particular, at least one of the two bearing devices is welded to the second fastening element in a third welding area under the applied preload force, creating at least a third welded connection with a third welding area of ​​the fastening element material of the second fastening element and a third welding area of ​​the bearing device material of one of the two bearing devices. This ensures increased stability in the electric drive component and further suppresses vibrations during operation. For example, the electric drive component is better protected against external forces, such as abrupt impacts, during operation.

[0021] Welded joints have the further advantage over adhesive joints, for example, that even if one of the welded joints were to develop cracks, which could develop further due to abrupt impacts during operation of the electric drive component, the welded bearing assembly in the area of ​​the welded joint would wedge itself with the second fastening element in such a way that the wedge-shaped and porous crack would prevent the parts from shifting axially against each other. This ensures the running stability of the electric drive component. By monitoring the smooth running of the electric drive component, for example by detecting vibrations or fluctuations in the power consumption of the electric drive component, such a fault could be detected and the electric drive component replaced as part of maintenance work.

[0022] Advantageously, at least one of the two fastening elements has a counterpart against which at least one of the two bearing devices is brought into contact before the preload force is applied, so that the applied preload force acts evenly on both bearing devices. The counterpart can be a stop on one of the two fastening elements, so that, for example, the first bearing device can be brought into contact easily and securely.

[0023] In particular, the counterpart is spaced apart from the opposite acting

[0024] The fastening element is arranged so that the bearing device arranged on the counterpart is securely seated. This ensures that the applied preload force is distributed sufficiently evenly across the two bearing devices in the electric drive component. In particular, the strength of the counterpart is designed to such an extent that it can at least bear the force of the applied preload force without the two fastening elements having to touch each other.

[0025] Preferably, at least the fastening element material of the first or second fastening element has a lower carbon content (less than 0.035%, preferably less than 0.01%), thus ensuring good weldability. Advantageously, the first or second fastening element material comprises a stainless austenitic steel, which has particularly good weldability due to the reduced carbon concentration.

[0026] Preferably, the first fastening element is a shaft of the electric drive component and the second fastening element is a housing part for the bearing devices, wherein at least one welded connection is created between a housing part material of the housing part and the bearing device material of one of the two bearing devices. The welded connection between the housing part and the bearing device is further away from a center of rotation of the shaft than the connection between the shaft and the bearing device, thereby making the welded connection easier to create. The greater distance from the center of rotation (radius) results in a longer circular ring segment. The longer circular ring segment makes it possible to create a longer weld seam and thus a longer welded connection between the housing part or a housing part material and the bearing device or a bearing device material.This allows more material to be welded, increasing the reliability of the welded joint. Additionally, more material can absorb the thermal energy during welding, reducing temperature peaks in the material that could lead to damage to, for example, storage equipment.

[0027] The applied preload force acts on both bearing devices and on the shaft, so that the at least one preloaded bearing device can be easily and reproducibly welded to the housing part. The housing part can be part of the stator of the electric drive component or can be firmly connected to the stator of the electric drive component. The housing part is preferably designed as a single piece in the area where the first and second bearing devices are arranged.In an alternative embodiment, the first and second bearing devices can also be arranged in a housing part each, but the two housing parts should be permanently and firmly connected to one another, for example with a flange, before the second fastening element is welded to the bearing device material, so that the preload is maintained across the firmly connected housing parts and does not change due to a displacement of the housing parts against one another.

[0028] As previously described, the shaft is also preferably integral in the area of ​​the first and second bearing devices. Alternatively, the first and second bearing devices can each be arranged on a single shaft section. However, the two shaft sections should be permanently and securely connected to one another, for example, by screwing or a flange, before the second fastening element is welded to the bearing device material. This ensures that the preload is maintained across the firmly connected shaft sections and does not change due to any relative displacement of the shaft sections.

[0029] Preferably, the shaft can also include a shaft sleeve. The shaft sleeve is typically arranged around the shaft and sits on the shaft with zero play during operation. The shaft sleeve can simplify the production of the electric drive component or have a carbon content optimized for welding.

[0030] Preferably, the welded joint between the housing part and an outer ring of one of the two bearing assemblies is a material-to-material bond. Additional materials or additional elements can be completely omitted during welding, creating a compact and reliable connection. The service life of the bearing assembly remains unchanged.

[0031] The at least one bearing device to be welded comprises, in particular, a hard material with a high carbon content (here 0.99%), which increases the hardenability of the bearing device. Such bearing devices are robust and durable.

[0032] Therefore, the material 100Cr6 is preferred as a bearing material.

[0033] In particular, the welded joint creates a material bond along the longitudinal extension of the outer ring of one of the two bearing assemblies. This means that the welded joint incorporates a higher proportion of the bearing assembly material, thus improving the stability of the welded joint.

[0034] Preferably, the welded joint is bonded to the outer ring edge of one of the two bearing assemblies. Welding the bearing assembly to be welded to the outer ring edge allows sufficient penetration of the bearing assembly material into the welded joint. The heat input into the bearing assembly material during welding is sufficiently high to create a reliable weld and prevent cracks in the welded joint.

[0035] Advantageously, the force of the applied preload is applied to the outer ring of one of the two bearing assemblies. The preload can be evenly distributed across the two bearing assemblies and at least one of the two fastening elements, resulting in an improved welded joint. This is particularly advantageous if at least one of the bearing assemblies is already firmly seated on the drive shaft.

[0036] In an alternative embodiment of the invention, the first fastening element is a housing part for the bearing devices, and the second fastening element is a shaft of the electric drive component, whereby at least one welded connection is created between a shaft material of the shaft and the bearing device material of one of the two bearing devices. The introduced preload force acts on both bearing devices and the housing part, so that the at least one preloaded bearing device can be welded to the shaft easily and securely.

[0037] Advantageously, the housing part can also include a sleeve for the housing part. A sleeve for the housing part can be arranged around or within the housing part and sits on the housing part without play during operation. The sleeve is preferably arranged in the area of ​​the housing part in which at least one of the two bearing devices is located. The sleeve for the housing part can simplify the production of the drive or have a carbon content optimized for welding.

[0038] In particular, the shaft is arranged such that at least one-fifth of the shaft length extends beyond at least one of the two bearing devices. This allows the two bearing devices to be securely fixed to the shaft and the applied preload force to be easily applied.

[0039] In particular, the length of the shaft is at least 1.5 times longer than the distance between the two bearing devices, so that the two bearing devices are stably arranged on the shaft.

[0040] Advantageously, the two bearing devices are arranged in direct or indirect contact with the shaft. During the manufacture of the electric drive component, the applied preload force acts directly on the first and second bearing devices, provided the two bearing devices are in direct contact. Alternatively, the applied preload force can be applied to at least one of the two bearing devices and then transferred to the other bearing device via further components, for example, the shaft or a housing part, so that, after the first welded joint has been created, a uniform preload is present on both bearing devices.

[0041] Preferably, the at least one welded joint is created by at least one weld seam forming a circular ring segment. The circular ring segment is arranged in the welding area. Welding circular ring segments is quick and easy to implement and therefore more cost-effective. In the simplest case, a welded joint can be a spot weld, which is created, for example, by pulse welding, for example, by a laser pulse. With pulse welding, less energy is introduced into the surrounding material than with continuous welding, which means that the material is heated less and thus protected. With pulse welding, the material must be well suited for welding. Pulse welding creates a weld spot as a weld joint. Several weld spots arranged in a row can result in a weld seam. However, the weld seam can also be created by continuous welding.Short weld seams are sufficiently stable because the static requirements for the weld are exceeded, especially with low prestress, and the welded area is reduced. In particular, at least the first weld seam has a weld seam length of at least 0.5 mm. Furthermore, the weld seam has a weld seam diameter or width of less than 0.5 mm, preferably less than 0.25 mm. This ensures that a sufficient amount of material is welded together to create a stable weld seam.

[0042] In particular, the circular ring segment extends 20° to 90° along a circular ring on one of the two bearing devices. This results in a stable and long weld seam between the second fastening element and one of the two bearing devices.

[0043] Preferably, a 40° circular ring segment is formed. The circular ring segment is a section of the circular ring. The circular ring runs along the connecting line between a bearing device and the second fastening element. The circular ring thus runs between an outer ring of a second bearing device and a housing part, or between an outer ring of a first bearing device and the housing part. The circular ring can also run between an inner ring of the second bearing device and the shaft, or between an inner ring of the first bearing device and the shaft.

[0044] Preferably, the circular ring segment extends 40° along a circular ring on one of the two bearing devices. This results in a sufficiently long weld seam between the second fastening element and one of the two bearing devices, which is sufficiently stable.

[0045] In particular, at least one weld seam is welded sequentially with at least two welding cycles, so that the at least one weld seam stably connects at least one bearing device to the second fastening element and the heat input at least into the bearing device is minimized.

[0046] In particular, the weld seam comprises three circular ring segments. The three circular ring segments can, for example, be divided into three weld connection sections or weld seam segments with different positioning. Finally, three weld connection sections, each with an angle of 10°, for example, are welded in one circular ring segment, evenly distributed around the circumference, with the welding beam directed towards the center of the gap between the second fastening element and the bearing device. Three further weld connection sections are welded with the welding beam directed 0.05–0.10 mm from the gap toward the bearing device. Furthermore, three further weld connection sections can be welded with the welding beam directed 0.05–0.10 mm from the gap toward the second fastening element. The individual weld connection sections of the circular ring segments can, for example, be spaced apart from one another so that they do not touch.The goal is to better accommodate manufacturing deviations and tolerances and achieve a good weld in at least one of the welded joint sections, thus reducing alignment effort while still reducing scrap. The short welds are particularly effective because the static requirements for the welded joint are far exceeded, thus reducing the number of welded surfaces and welded joints.

[0047] Preferably, the circular ring segment consists of at least two welded connection sections, wherein the at least two welded connection sections are arranged along the circumference of the outer ring of the bearing device or the inner ring of the bearing device. The at least two welded connection sections can be arranged side by side. The welding beam is aligned centrally at the joint gap. This ensures that the weld seam encompasses both the bearing device material and the fastening element material at a sufficient number of welded connection sections.

[0048] A welded joint section or weld seam segment is part of a circular ring segment and can be created by at least one weld seam or by one or more weld spots. A welded joint section can always have a constant radial offset of the welded joint from the shaft's center of rotation. A welded joint section extends 10° to 40°, preferably 20 to 30°, along a circular ring.

[0049] In particular, the at least two welded connection sections have a radial offset of at least 0.1% of the radius of the outer ring of the bearing device. This compensates for manufacturer-specific dimensional deviations or tolerances of the bearing device and the fastening elements, ensuring that a sufficiently good welded connection is created with at least one welded connection section. Furthermore, the effort required to align the electric drive component can be reduced, while simultaneously reducing the amount of scrap due to defective electric drive components.

[0050] Preferably, the circular ring segment consists of three welded connection sections, wherein the welded connection sections have a radial offset of at least 0.1% of the radius of the outer ring of the bearing device. This ensures that the weld seam is located outside the center of the joint gap at several welded connection sections and encompasses both the bearing device material of the bearing device and the fastening element material of the fastening material.

[0051] Advantageously, welding is performed three or two times in each of the three areas. For example, the first three welded sections are performed with the welding beam aligned to the center of the joint gap. The subsequent three welded sections in each of the welding areas are then performed with the welding beam aligned 0.05–0.10 mm closer to the bearing device. The third welded sections in each of the three welding areas are, in particular, performed with the welding beam aligned 0.05–0.10 mm closer to the second fastening element. The steps described above can also be performed on circular ring segments with fewer than three or more than three welded sections.This allows manufacturer-related dimensional deviations in the bearing device to be compensated, so that a faulty welded joint is ruled out and there is no rejection of the electrical drive components due to a faulty welded joint.

[0052] Preferably, at least one of the welded joints comprises less than 40% of the bearing device material of one of the two bearing devices. The remaining portion of the melt of a welded joint can consist, for example, of a fastener material. During welding, the high proportion of carbon in the material to be welded is a disadvantage, as a high amount of thermal energy is introduced into the bearing device to be welded for a very short time and in a localized manner. Normally, weld seams on bearing devices harden to such an extent that they develop cracks simply due to shrinkage during cooling. Furthermore, excessive heating of the bearing device would lead to distortion and thus to reduced running smoothness or service life. Reducing the proportion of bearing device material in the melt for at least one welded joint reduces crack formation in the welded joint.

[0053] Preferably, at least one of the welded joints comprises less than 20% of the bearing device material of one of the two bearing devices. Further reducing the proportion of bearing device material for the at least one welded joint prevents crack formation in the welded joint. Thus, by further increasing the amount of non-bearing device material in the melt, rejects of the welded joint or components can be avoided.

[0054] Preferably, at least one of the welded joints is created using a fusion welding process using radiation. Additional materials or additional elements can be omitted. For example, laser welding or electron beam welding is used. The welding steel used in laser welding has a sufficiently large beam diameter so that manufacturer tolerances of the bearing devices are compensated and a sufficiently stable welded joint can be created. The welding steel used in electron beam welding has a small beam diameter, allowing a thinner weld seam to be created. The thermal energy can be applied almost point-like by a welding beam within a very small radius, allowing the material of the fastening element and the bearing device to be melted very precisely and locally.Due to the precise melting, the proportion of the storage device material in the total melt can be determined relatively accurately.

[0055] In particular, the welding beam is directed between the outer ring edge of one of the two bearing devices and the housing part. This ensures that both the bearing device material and the housing part material of the housing part or the sleeve material of the sleeve of the housing contribute to the weld joint.

[0056] Alternatively or additionally, the welding beam is directed between the outer edge of the inner ring of one of the two bearings and the shaft. This ensures that both the bearing material and a shaft material or the sleeve material of the shaft sleeve contribute to the weld joint.

[0057] Preferably, the preload force is between 1 Newton and 500 Newton. This allows a sufficiently large preload to be generated in the electric drive component.

[0058] The preload force is preferably between 20 Newtons and 90 Newtons, particularly preferably approximately 50 Newtons. This allows sufficient preload to be generated in the electric drive component so that the electric drive is free of play and the electric drive component is protected. A high preload can reduce the efficiency of the electric drive component due to bearing friction. Furthermore, excessive preload can reduce the service life of the bearing, for example by increasing wear in the bearing. The preload force is the remaining preload force that is present between the two bearing devices after the welded joint has been created and the manufacturing device has been removed. Ideally, this corresponds to the preload force applied during the creation of the welded joint.

[0059] Preferably, the first bearing device is pressed onto the first fastening element. Pressing the first bearing device onto the first fastening element positions the first bearing device locally in the electric drive component before the preload force is applied. The bearing device should be non-positively and permanently connected to the first fastening element so that after the preload is applied, the bearing device does not shift relative to the first fastening element and the preload is not changed or reduced. The first bearing device should be connected to the first fastening element before it is connected to the second fastening element.

[0060] Alternatively or additionally, the second bearing device is pressed onto the first fastening element. Pressing the second bearing device onto the first fastening element also positions the second bearing device locally within the electric drive component before the preload force is applied, so that a uniformly distributed preload can be generated within the electric drive component. The second bearing device should also be non-positively and permanently connected to the first fastening element. The connection of the second bearing device to the first fastening element should occur before connecting it to the second fastening element.

[0061] In particular, at least one of the two bearing devices is bonded to the first fastening element. The bonding serves for assembly purposes to prevent the at least one bearing device from shifting during the manufacture of the electric drive component and becoming jammed in an unsuitable position.

[0062] Preferably, a concave weld surface is created at the weld seam. If no filler material is used during welding, the weld seam is not filled, or not completely filled, with molten metal. This results in an under-arched (concave) weld seam. During the welding process, only the fastener material of the second fastener and the bearing device material of one of the two bearing devices are melted and joined together without any additional material, e.g., in the form of a wire, an attached ring, or sprayed-in powder.

[0063] Preferably, the weld seam is created with a weld seam width of less than 0.5 mm, in particular a weld seam width of less than 0.25 mm. The weld seam width refers to the width of the weld seam at the surface of the weld seam. A thin weld seam reduces the amount of thermal energy introduced into the joint during the welding process. This reduces the thermal stress, particularly on the bearing device, thus preventing damage to the bearing device.

[0064] An electric drive component according to the invention comprises at least one first fastening element, wherein at least one first and one second bearing device are preloaded on the first fastening element. The preload acts due to at least one welded connection between a fastening element material of a second fastening element and a bearing device material of one of the two bearing devices.

[0065] The preload prevents axial vibration of the bearing devices and the components arranged on the bearing device in the electric drive component during operation, so that the electric drive component is free of play. The welded connection thus ensures that the second fastening element and one of the two bearing devices are preloaded and mechanically connected to one another in the electric drive component. This eliminates the need for spring elements for applying preload or axial ring locks, and prevents axial natural vibrations during operation of the electric drive component. The electric drive component can be designed as a motor or as a gear unit. The electric drive component is overall more robust and remains operationally stable even when exposed to external forces such as impacts, thus improving the performance of the electric drive component.In particular, the welded joint is produced by applying a prestressing force according to one of the methods mentioned above.

[0066] Specifically, the two bearing assemblies are a first and second rolling bearing assembly. The preload in the electric drive component causes the rolling elements to rest against the outer and inner rings of the bearing assemblies, preventing axial movement in the bearing assemblies and thus improving the smooth running of the bearing assemblies. Axial stability of the bearing assemblies increases the performance and service life of the electric drive component during operation.

[0067] Preferably, the first fastening element is the shaft of the electric drive component, and the second fastening element is a housing part for one of the two bearing devices. Additionally, a sleeve can be arranged on the shaft of the electric drive component. The applied preload force acts on the two bearing devices and the shaft, so that at least one of the preloaded bearing devices can be welded to the housing part in a positionally secure and reproducible manner.

[0068] Alternatively, the first fastening element is a housing part for the bearing devices, and the second fastening element is the shaft. The introduced preload force acts on the two bearing devices and the housing part, so that at least one of the bearing devices can be welded to the shaft in a preloaded manner in a positionally secure and reproducible manner. Preferably, the at least one welded connection has at least one weld seam forming a circular ring segment. Welding circular ring segments is quick and easy to implement and therefore cost-effective. In the simplest case, the circular ring segment can be a spot weld. The short weld seams are sufficiently stable; since the static requirements for the welded connection are relatively low due to low preload forces, the welded area can be relatively small.

[0069] In particular, the circular ring segment extends 20° to 90° along a circular ring on one of the two bearing devices. This results in a stable and sufficiently long weld seam between the fastener material of the second fastener and the bearing device material of one of the two bearing devices.

[0070] Preferably, the circular ring segment extends 40° along a circular ring on one of the two bearing devices. This results in a sufficiently long weld seam between the fastening element material of the second fastening element and the bearing device material of one of the two bearing devices, which is sufficiently stable.

[0071] In a preferred embodiment, the at least one weld seam is designed as a spot weld connection consisting of several weld points arranged in a row.

[0072] In a further preferred embodiment, the at least one weld seam is designed as a spot weld connection consisting of several spaced-apart welding points.

[0073] Two adjacent welds of the spaced spot welds of the weld seam preferably have an angle along a circular ring of at most 10° and in particular of at most 5° to each other.

[0074] Preferably, the circular ring segment consists of at least two welded connection sections, wherein the at least two welded connection sections are arranged along the circumference of the outer ring of the bearing device or the inner ring of the bearing device. The at least two welded connection sections can be arranged side by side. The welding beam is aligned centrally at the joint gap. This ensures that the weld seam encompasses both the bearing device material and the fastening element material at a sufficient number of welded connection sections.

[0075] A welded joint section can be created by at least one weld seam. A welded joint section can also be created by multiple weld points. A welded joint section can always have a constant radial offset of the welded joint relative to the shaft's rotation center.

[0076] In particular, the at least two welded connection sections have a radial offset of at least 0.1% of the radius of the outer ring of the bearing device. This compensates for manufacturer-specific dimensional deviations or tolerances of the bearing device and the fastening elements, ensuring that a sufficiently good welded connection is created with at least one welded connection section. Furthermore, the effort required to align the electric drive component can be reduced, while still reducing scrap. As previously described, in a further embodiment, the electric drive component has at least one circular ring segment with three welded connection sections. Furthermore, the two or three welded connection sections can also be welded multiple times.

[0077] Preferably, the welded joint is arranged between the second fastening element and an outer ring of one of the two bearing assemblies. Additional materials or additional elements can be completely dispensed with during welding, thus creating a compact and reliable connection. The service life of the bearing assembly remains unchanged.

[0078] In particular, the welded joint creates a material bond along the longitudinal extension of the outer ring of one of the two bearing assemblies. This allows the welded joint to enclose more of the bearing assembly material along the longitudinal extension, thus improving the stability of the welded joint.

[0079] Preferably, the welded joint is formed by a material bond on the outer ring edge of one of the two bearing assemblies. Welding the bearing assembly to be welded to the outer ring edge allows for a sufficient amount of bearing assembly material to be introduced into the welded joint. The heat input into the bearing assembly material during welding is sufficiently high to create a reliable weld and prevent hot cracks.

[0080] Preferably, the first bearing device is pressed onto the first fastening element. Pressing the first bearing device onto the first fastening element positions the first bearing device in the electric drive component before the preload force is applied.

[0081] Alternatively or additionally, the second bearing device is pressed onto the first fastening element. Pressing the second bearing device onto the first fastening element also positions the second bearing device in the electric drive component before the preload force is applied, so that a uniformly distributed preload can be generated in the electric drive component. In particular, one of the two bearing devices is axially fixed, thus preventing axial play.

[0082] Preferably, the weld seam has a concave seam surface. If no filler material is used during welding, the weld seam is not filled, or not completely filled, with molten metal. This results in an under-arched (concave) weld seam. During the welding process, only the fastener material of the second fastener and the bearing device material of one of the two bearing devices are melted and joined together without any additional material, e.g., in the form of a wire, an attached ring, or sprayed-in powder.

[0083] Using additional, more weldable material, such as a ring pressed onto the bearing assembly, would require an additional part to be procured and pressed on in an additional step. This would increase production costs. Therefore, it is preferable to avoid using filler material for welding; the lack of filler material creates a concave weld surface.

[0084] Preferably, the weld seam has a weld seam width of less than 0.5 mm, in particular a weld seam width of less than 0.25 mm. The weld seam width refers to the width of the weld seam at the surface of the weld seam. A thin weld seam reduces the amount of thermal energy introduced into the joint during the welding process. This reduces the thermal load, particularly on the bearing device, thus preventing damage to the bearing device.

[0085] A manufacturing device according to the invention for producing an electric drive component with at least two preloaded bearing devices, comprising a holding device for holding at least one second fastening element, with at least one means for applying a preload force to one of the two bearing devices, and a device for creating at least one welded connection by fusion welding with radiation. This allows the production of a play-free electric drive component as described herein.

[0086] The holding device can comprise a collet with a stop so that the electrical drive component can be easily picked up, centered and axially positioned.

[0087] To apply the preload force, a weight can act on at least one support point on at least one of the two bearing devices, allowing a reproducible preload force to be generated. This makes it easy to manufacture the electric drive components in multiple series with the same performance capabilities. In particular, the weight acts on three support points on at least one of the two bearing devices, enabling a more even application of the preload force.

[0088] Alternatively or additionally, a preload plate can be used which can be attached to the electric drive component and which reproducibly applies the necessary preload force, for example pneumatically, hydraulically, magnetically, via springs, by means of clamping screws or otherwise mechanically.

[0089] The device for creating a welded joint can be arranged on a positioning device, which can be connected to the holding device. This allows the welding beam of the device to be precisely positioned. An electric drive according to the invention comprises an electric drive component as described above, wherein the electric drive component comprises at least two bearing devices and a preload acts on the two bearing devices. The preload acts due to at least one weld connection between a fastening element material of the second fastening element and a bearing device material of one of the two bearing devices, which are welded under an acting preload force (Fv).

[0090] The preload prevents axial vibration in the electric drive component during operation. The welded connection ensures that the second fastening element and one of the two bearing devices are mechanically connected to each other in a preloaded manner within the electric drive component. This eliminates the need for spring elements for applying preload or axial ring locks, and prevents axial natural vibrations during operation of the electric drive. This allows for a lightweight electric drive with fewer components and high performance and service life.

[0091] In addition to the mechanical components, an electric drive also includes a control device for controlling the electric drive and may include a power supply for supplying the electric drive with electrical energy. The control device has control commands that allow the electric drive to operate with increased performance. This is possible because the electric drive component, as described above, is free of play, preventing natural vibration in the electric drive.

[0092] Further advantages, features and details of the invention will become apparent from the following description, in which embodiments of the invention are described with reference to the drawings.

[0093] The list of reference symbols, as well as the technical content of the patent claims and figures, is part of the disclosure. The figures are described coherently and comprehensively. Identical reference symbols indicate identical components; reference symbols with different indices indicate functionally identical or similar components. The invention is explained in more detail with reference to exemplary embodiments in the following figures.

[0094] Positional references such as “top”, “bottom”, “right” or “left” refer to the respective illustrations and are not to be understood as limiting.

[0095] Although the invention is illustrated and described in detail by means of the figures and the associated description, this illustration and this detailed description are to be understood as illustrative and exemplary and not as limiting the invention. It is understood that those skilled in the art may make changes and modifications without departing from the scope of the following claims. In particular, the invention also encompasses embodiments with any combination of features mentioned or shown herein for various aspects and / or embodiments.

[0096] The invention also encompasses individual features in the figures, even if they are shown there in conjunction with other features and / or not mentioned above. Furthermore, the term "comprising" and derivatives thereof do not exclude other elements or steps. Likewise, the indefinite article "a" or "an" and derivatives thereof do not exclude a plurality. The functions of several features listed in the claims may be fulfilled by a single unit. The terms "essentially," "about," "approximately," and the like, in connection with a property or value, specifically define the property or value. All reference signs in the claims are not to be understood as limiting the scope of the claims.

[0097] Character description

[0098] The figures are described in a coherent and comprehensive manner. The same reference symbols refer to the same components.

[0099] Fig. 1: a first method according to the invention for producing an electric drive component in a simplified flow diagram; Fig. 2: a first inventive electric drive component in a simplified schematic sectional view;

[0100] Fig. 3: a section of the welding area B1 of the electric drive component according to Fig. 2 in a sectional view;

[0101] Fig. 4: a schematic detailed representation of the electric drive component according to Fig. 2 with a second fastening element in a manufacturing device in a plan view;

[0102] Fig. 5a: a micrograph of a welded joint S1 on the electrical drive component according to Fig. 2;

[0103] Fig. 5b: a schematic cross-section of a welded joint S1 on the electrical drive component according to Fig. 2;

[0104] Fig. 6: the welded connections on the electrical drive component according to Fig. 2 in a schematic representation;

[0105] Fig. 7: the welded joint from Fig. 6 in a special sectional view;

[0106] Fig. 8: another inventive method for producing an electric drive component in a simplified flow chart;

[0107] Fig. 9: a second inventive electric drive component in a simplified schematic sectional view;

[0108] Fig. 10: an inventive manufacturing device for producing an electric drive component according to Fig. 2 using the method according to Fig. 1 in a perspective sectional view, and

[0109] Fig. 11: an electric drive according to the invention with an electric drive component according to Fig. 2 in a sectional view. Embodiment of the invention

[0110] Figure 1 shows a first embodiment of a method for producing an electric drive component 20 with at least two bearing devices 21, 25 and Figures 2 to 4 show the electric drive component 20 with the at least two bearing devices 21, 25 as rolling bearing devices.The method according to Figure 1 comprises at least the following steps: a) providing a shaft 30 as a first fastening element 31; b) arranging the first bearing device 21 on the shaft 30; c) arranging the second bearing device 25 on the shaft 30; d) introducing a preload force Fv onto the second bearing device 25, wherein e) the introduced preload force Fv causes a force to act on both bearing devices 21, 25, and f) the second bearing device 25 is welded to a housing part 35 for the bearing devices 21, 25 as a second fastening element 36 in a welding area B1, B2, B3 while the preload force Fv is acting, whereby at least one welded connection S1, S2, S3 is created between a housing part material of the housing part 35 and a bearing device material of the second bearing device 25.

[0111] The rolling bearing devices 21, 25 are depicted as ball bearing devices and each comprise an inner ring 22, 28, balls 23, 26, and an outer ring 24, 27. The housing part 35 has a stop 37 against which the first bearing device 21 is brought into direct contact before the preload force Fv is introduced in step b), so that the introduced preload force Fv acts evenly on both bearing devices 21, 25. The first bearing device 21 can additionally be bonded to the housing part 35 at the outer ring 24. The bonding serves, in particular, to prevent the bearing device 21 from shifting or jamming during the manufacture of the electric drive component 20. When arranging the first bearing device 21 and the second bearing device 25 on the shaft 30 according to steps b) and c), they are pressed onto the respective inner ring 22, 28 with the shaft 30.The preload force Fv is introduced at the second bearing device 25 and is then transferred via the shaft 30 to the first bearing device 21, so that, after the welded connection S1, S2, S3 has been created, a preload is present at both bearing devices 21, 25 - see force line KL of the preload in Figure 2. The electrical drive component 20 can be used for an electric motor and / or in a gearbox. The electrical drive component 20 can thus comprise both a gearbox and an electric motor. The method for arranging the bearing devices 21, 25 is suitable for both gearboxes and electric motors or a combination consisting of a gearbox and an electric motor.

[0112] The preload force Fv is introduced into the electric drive component 20 in a uniformly distributed manner via the two bearing devices 21, 25 and the shaft 30. The preload force Fv can have a value between 20 Newtons and 90 Newtons.

[0113] The welded joint S1, S2, S3 acts as a material bond between the housing part 35 and an outer ring edge 29 of the outer ring 27 of the second bearing device 25. The force effect of the introduced preload force Fv is first applied to the outer ring 27 of one of the two bearing devices 21, 25. The preload force Fv is applied to that of the two bearing devices 21, 25 that is not fixedly positioned relative to the housing part 35, e.g., by a stop 37 or adhesive bond.

[0114] Figure 4 shows the electrical drive component 20 according to Figures 2 and 3 in a plan view. The electrical drive component 20 has the welded joints S1, S2, S3 in the welded areas B1, B2, B3, which were created under the acting preload force Fv. Figure 4 shows that the second bearing device 25, when the acting preload force Fv, rests against the housing part 35 for the bearing devices 21, 25 as a second fastening element 36 in several welded areas B1, B2, B3, whereby the welded joint S1, S2, S3 between the housing part material of the housing part 35 and the bearing device material of the second bearing device 25 can be created in a further step g).

[0115] The welded joints S1, S2, S3 act in a materially bonded manner between the housing part 35 and an outer ring outer edge 29 of the outer ring 27 of the second bearing device 25. The force effect of the introduced preload force Fv is introduced onto the outer ring 27 of one of the two bearing devices 21, 25. A holding device 210 can be used to generate a preload force Fv on one of the two bearing devices 21, 25 - see also Figure 10. The holding device 210 has three support points 212. The holding device 210 rests with a weight 211 on these support points 212 on the outer ring 27 of the second bearing device 25 and thereby transfers the preload force Fv to the second bearing device 25. Openings 213 are provided between the support points 212. The openings 213 enable the production of welded joints S1, S2, S3 in the welding areas B1, B2, B3.The welded joints each consist of a weld seam 41, which extends over a circular ring segment 42 in each of the welding areas. The welded joints between the housing part 35 and one of the two bearing devices 21, 25 are created while a preload force Fv acts on the second bearing device 25. As a result, the two bearing devices 21, 25 are preloaded after the welded joints S1, S2, S3 have been created.

[0116] Figure 5a shows the welded joint S1, S2, S3 on the electrical drive component according to Figure 2 and Figure 3 in a photographic representation. Figure 5b shows the welded joint S1, S2, S3 on the electrical drive component according to Figure 2 and Figure 3 in a schematic representation. The housing part 35 has a low carbon content (0.035%) and comprises a stainless austenitic steel. The second bearing device 25 or the outer ring 27 comprises a high proportion of carbon (here 0.99%), which increases the hardenability of the second bearing device 25 and is made of the material 100Cr6. The welded joints S1, S2, S3 are produced using laser beam welding technology. The weld steel 40 used in laser welding has a sufficiently large beam diameter so that manufacturer tolerances of the second bearing device 25 are absorbed.The welding beam 40 also has a sufficiently small beam diameter to melt as little material as possible from the outer ring 27 of the second bearing device 25 and the housing 35. This ensures that as little thermal energy as possible is supplied to the welded joint S1, S2, S3, resulting in low thermal stress, particularly on the second bearing device 25. The welding beam 40 is directed between the outer ring outer edge 29 of the second bearing device 25 and the housing part 35. Care is taken to ensure that the welded joints S1, S2, S3 comprise less than 40% or less than 20% of the bearing device material of the outer ring 27 of the second bearing device 25, and thus comprise at least 60% or at least 80% of the housing material of the housing part 35. During welding, the preload force Fv acts on the two bearing devices 21, 25.

[0117] The weld joint S1 shown in Figure 5a, in the form of a weld seam 41 or a spot weld, has a concave seam surface. The weld seam 41 was produced without additional material, in the form of a fed wire, an attached ring, or sprayed-in powder. As a result, the weld joint is not or not completely filled with melt. Only the existing fastening element material of the second fastening element 36 is melted with a bearing device material of one of the two bearing devices 21, 25, as is usual with laser beam or electron beam welding. The weld seam 41 is thus produced in a process in which no additional material is used for welding, whereby an under-arched (concave) seam surface is produced.

[0118] Figure 6 shows the welded joint S1, S2, S3 in a welded area B1, B2, B3 on the electric drive component 20 in a schematic representation according to Figure 4 and Figures 5a + 5b, wherein the welded joint S1, S2, S3 extends in a materially bonded manner along the longitudinal extent of the outer ring 27 of the second bearing device 25 and the welded joint S1, S2, S3 forms a circular ring segment 42 which extends 60° along a circular ring on the second bearing device 25. The circular ring segment 42 comprises three welded joint sections 43, 44, 45, or weld seam segments, wherein the three welded joint sections 43, 44, 45 are arranged along the circumference of the outer ring 27 of the second bearing device 25. The first and third welded connection sections 43, 45 have a radial offset of at least 0.1% of the radius of the outer ring 27 of the second bearing device 25 compared to the second welded connection section 44.The first welded connection section 43 is offset inwards towards the outer ring 27 of the second bearing device 25, and the third welded connection section 45 is offset outwards towards the housing part 35. This ensures that the welded connection S1, S2, S3 is located at several welded connection sections even outside the center of the joint gap between the outer ring 27 and the housing part 35 and comprises both the bearing device material and the housing part material in different compositions. Figure 7 shows an alternative welded connection SX which was created using the previously described method or the electric drive component 20 according to Figures 1 to 6, in a schematic sectional view, wherein on the circular ring segment 42, each of the three welded connection sections 43, 44, 45 is welded once in each of the welding areas B1, B2, B3.Three circular ring segments 42 are provided on the electric drive component 20. The example of the weld joint SX.2 shows that the welding is carried out with a welding beam orientation at the weld joint section 44 initially toward the center of the joint gap between the second bearing device 25 and the housing part 35. The weld joint SX.1 is carried out in the same welding area B with a welding beam orientation 0.10 mm closer to the second bearing device 25. The third weld joint SX.3 is carried out on the same circular ring segment 42 in the third weld joint section 45 with a welding beam orientation 0.10 mm closer to the housing part 35.The illustration is intended to show the course of the weld seam 41 in a circular ring segment 42 in the material of the electric drive component 20 with different orientations of the welding beam 40 to the joint gap between the outer ring 27 of the second bearing device 25 and the housing part 35 or, in other embodiments, the inner ring 28 of the second bearing device and the shaft 30. The illustration is schematic and is not a true sectional view, with the sectional plane changing along the circumference of the weld connection sections 43, 44, 45.

[0119] Figure 8 shows a further embodiment of a method for producing an electric drive component 120 with at least two bearing devices 121, 125 and Figure 9 shows the electric drive 120 with the at least two bearing devices 121, 125 as rolling bearing devices.The method according to Figure 8 comprises at least the following steps: a) providing a housing part 135 for the bearing devices 121, 125, as a first fastening element 136; b) arranging the first bearing device 121 on the housing part 135; c) arranging the second bearing device 125 on the housing part 135; d) introducing a preload force Fv onto the second bearing device 125, wherein e) the introduced preload force Fv causes a force to act on both bearing devices 121, 125; and f) the second bearing device 125 is welded to a shaft 130 as a second fastening element 131 in a welding area B1, B2, B3 while the preload force Fv is acting, whereby at least one welded connection S1, S2, S3 is created between a shaft material of the shaft 130 and a bearing device material of the second bearing device 125.

[0120] The method for manufacturing the electric drive component 120 is essentially as previously disclosed in Figures 1 to 8, however, the welding beam 40 is directed between an inner ring outer edge of the inner ring 128 of the second bearing device 125 and the shaft 130 to create the welded joints S1 to S3, as previously disclosed in Figures 5a to 7. This ensures that both the bearing device material of the second bearing device 125 and the shaft material of the shaft 130 contribute to the welded joint S1, S2, S3. The preload force Fv is introduced at the second bearing device 125 and is then transferred via the housing part 135 to the first bearing device 121, so that, after the welded joint S1, S2, S3 has been created, a preload is present at both bearing devices 121, 125 - see force line KL of the preload in Figure 9.When arranging the first bearing device 121 and the second bearing device 125 on the housing part 135 according to steps b) and c), they can be pressed onto the respective outer ring 122, 127 of the housing part 135. Alternatively, the first and second bearing devices 121, 125 can also be welded or soldered to the housing part 135. The housing part 135 has a stop 37 against which the first bearing device 121 is brought into direct contact before the preload force Fv is introduced in step b). The introduced preload force Fv acts evenly on both bearing devices 121, 125. An inner ring 122 of the first bearing device 121 can have a press fit relative to the shaft 130. As a result, the inner ring 122 of the first bearing device 121 is pressed onto the shaft 130.The inner ring 122 of the second bearing device 125 preferably has a transition fit or a clearance fit relative to the shaft 130, so that after applying a preload Fv, a displacement between the inner ring 122 and that of the shaft 130 is possible. The electric drive component 120 can, in turn, be used for an electric motor or in a transmission.

[0121] In a further embodiment of the method according to Figure 8, at least the welded joint S1, S2, S3 can be created on a sleeve for the shaft 130, wherein the sleeve is firmly seated on the shaft 130 (not shown). In a further embodiment not shown, both a welded joint S1, S2, S3 can be created between the housing part 135 for the first bearing device 121 and the second bearing device 125, as well as a further welded joint between the shaft 130 and one of the two bearing devices 121, 125 (not shown).

[0122] Figure 10 shows a manufacturing device 200 for manufacturing the electric drive component 20 according to Figures 2 to 7 and using the method according to Figure 1. The manufacturing device comprises a holding device 210 for holding the electric drive component 20 and at least one weight 211 for applying a preload force Fv to the second bearing device 25 as well as a laser welding device 250 for creating a welded connection S1, S2, S3 using a welding beam 40. The weight 211 acts on the second bearing device 25 at three support points 212, which are each offset by 120° to one another. An opening 213 is provided on the weight 211, so that the welding beam 40 can be beamed through the opening 213 onto the electric drive component 20 with precise positioning. It is possible to move the holding device 210 relative to the laser welding device 250 in order to create the welded joints S1, S2, S3.However, it is also possible to position the welding beam 40 by deflection such that the weld joints S1, S2, and S3 are created at the intended positions. The position of the welding areas B1 to B3 for the weld joints S1 to S3 can thus be determined reproducibly and precisely.

[0123] The laser welding device 250 can be connected to a positioning device 251, which is connected to the holding device 210.

[0124] Alternatively or additionally, a preload plate can be used, for example, which can be fastened to the electric drive component 20 and reproducibly applies the necessary preload force pneumatically, via springs or otherwise mechanically (not shown).

[0125] Figure 11 shows an electric drive 300 with two bearing devices 21, 25 with an electric drive component 20, as previously described in Figures 1 to 7, consisting of an electric motor 301 and a gear 302, wherein the electric drive component 20 comprises the two bearing devices 21, 25 and a preload acts on the two bearing devices 21, 20. The preload acts due to at least one welded connection S1, S2, S3 between a housing material of the housing part 35 and a bearing device material of the second bearing device 25. The electric drive device 300 can comprise both an electric motor 301 and a gear 302. The electric drive device 300 comprises, in addition to the electrical and mechanical components, as listed non-exhaustibly, the shaft 30, a housing 34, electrical coils 33, and magnets 38.The electrical coils 33 can be spaced apart from the drive shaft 30 and arranged on the housing part 35. The diameter of the electrical coils 33 can be larger than the diameter of the drive shaft 30. The magnets 38 are arranged directly adjacent to the electrical coils 33. Furthermore, a control device 310 for controlling the electrical drive component 20 and a supply device 320 for supplying the electrical drive component 20 with electrical energy are also present, which are connected to the electrical drive component 20 via a data cable 311 and a supply cable 321. The control device 310 can have control commands that drive the electrical drive component 20, preferably with increased performance.

[0126] List of reference symbols

[0127] 20 Electric drive components

[0128] 21 First bearing device - ball bearing device

[0129] 22 inner ring of 21

[0130] 23 balls out of 21

[0131] 24 outer ring of 21

[0132] 24a Outer ring outer edge of 24

[0133] 25 Second bearing device - ball bearing device

[0134] 26 balls out of 25

[0135] 27 outer ring of 25

[0136] 28 inner ring of 25

[0137] 29 Outer ring outer edge of 27

[0138] 30 wave of 20

[0139] 31 First fastening element

[0140] 33 Electrical coils (not shown)

[0141] 34 Housing (not shown)

[0142] 35 Housing part

[0143] 36 Second fastening element

[0144] 37 stop

[0145] 38 magnets (not shown)

[0146] 40 welding beam

[0147] 41 Weld seam

[0148] 42 circular ring segment

[0149] 43 First welded joint section of 42

[0150] 44 Second welded joint section of 42

[0151] 45 Third weld connection section of 42

[0152] B1, B2, B3 welding areas

[0153] S1 First welded joint

[0154] S2 Second weld joint

[0155] S3 Third weld joint

[0156] SX welded joint

[0157] SX.1 First welded joint

[0158] SX.2 Second weld joint

[0159] SX.3 Third weld joint

[0160] Fv preload force

[0161] KL Line of force from Fv a)-g) Process steps

[0162] 120 Electric Drive First Bearing Device - Ball Bearing Device Inner Ring of 121

[0163] Second bearing device - ball bearing device

[0164] Outer ring of 125

[0165] inner ring of 125

[0166] Shaft of 120 second fastener

[0167] Housing part

[0168] First fastening element

[0169] Manufacturing device

[0170] Holding device

[0171] Weight

[0172] Support points

[0173] Opening in 211

[0174] Laser welding device

[0175] Positioning device

[0176] Electric drive

[0177] electric motor

[0178] Gearbox

[0179] Control device

[0180] Data cable

[0181] Supply facility

[0182] supply cable

Claims

Patent claims 1. A method for producing an electric drive component (20; 120) with at least two bearing devices (21, 25; 121, 125), in particular at least two rolling bearing devices, comprising at least the following steps: a) providing a first fastening element (31; 136); b) arranging a first bearing device (21, 121) on the first fastening element (31; 136); c) arranging a second bearing device (25, 125) on the first fastening element (31; 136); d) introducing a preload force (Fv) onto at least one of the two bearing devices (21, 25; 121, 125), wherein e) the introduced preload force (Fv) effects a force on both bearing devices (21, 25; 121, 125); and f) at least one of the two bearing devices (21, 25; 121, 125) is connected to at least one second fastening element (36;131) is welded in at least one welding area (B1, B2, B3), whereby at least one welded connection (S1, S2, S3) is formed between a fastening element material of the second fastening element (36; 131) and a bearing device material of one of the two bearing devices (21, 25; 121, 125); 2. Method according to claim 1, characterized in that the first fastening element (31) is a shaft (30) of the electric drive component (20) and the second fastening element (36) is a housing part (35) for the bearing devices (21, 25; 121, 125), wherein at least one welded connection (S1, S2, S3) is created between a housing part material of the housing part (35) and the bearing device material of one of the two bearing devices (21, 25).

3. Method according to claim 2, characterized in that the welded connection (S1, S2, S3) between the housing part (35) and a Outer ring (27) of one of the two bearing devices (21, 25) acts in a materially bonded manner, wherein the welded connection (S1, S2, S3) acts in a materially bonded manner in particular on the longitudinal extent of the outer ring (27) of one of the two bearing devices (21, 25), and preferably the welded connection (S1, S2, S3) acts in a materially bonded manner on an outer ring outer edge (29, 24a) of one of the two bearing devices (21, 25), and advantageously the force effect of the introduced prestressing force (Fv) is introduced onto the outer ring (27, 24) of one of the two bearing devices (21, 25).

4. Method according to claim 1, characterized in that the first fastening element (136) is a housing part (135) for the bearing devices (121, 125) and the second fastening element (131) is a shaft (130) of the electric drive component (20), wherein at least one welded connection (S1, S2, S3) is formed between a shaft material of the shaft (130) and the bearing device material of one of the two bearing devices (121, 125).

5. Method according to one of the preceding claims, characterized in that the at least one welded connection (S1, S2, S3) is produced by at least one weld seam (41) which forms a circular ring segment (42) which extends in particular 20° to 90°, preferably 40°, along a circular ring on one of the two bearing devices (21, 25; 121, 125).

6. Method according to claim 5, characterized in that the at least one weld seam (41) is designed as a spot weld connection from a plurality of welding points arranged in a row or from a plurality of welding points spaced apart from one another.

7. The method according to claim 5 or 6, characterized in that the circular ring segment (42) consists of at least two welded connection sections (43, 44, 45), wherein the at least two welded connection sections (43, 44, 45) are arranged along the circumference of the outer ring (27) of the bearing device (21, 25) or the inner ring (128) of the bearing device (121, 125) and in particular have a radial offset of at least 0.1% of the radius of the outer ring (27) of the bearing device (21, 25; 121, 125) relative to one another.

8. Method according to one of the preceding claims, characterized in that the at least one welded joint (S1, S2, S3) comprises less than 40% of the bearing device material of one of the two bearing devices (21, 25; 121, 125), and in particular comprises less than 20% of the bearing device material.

9. Method according to one of the preceding claims, characterized in that the prestressing force (Fv) has a value of 1 Newton to 500 Newton, in particular 20 Newton to 90 Newton.

10. Method according to one of the preceding claims, characterized in that the first and / or second bearing device (21, 25; 121, 125) is pressed with the first fastening element (31; 136).

11. Electric drive component (20; 120) comprising at least one first fastening element (31; 136), wherein on the first fastening element (31; 136) at least one first and one second bearing device (21, 25; 121, 125), in particular first and second rolling bearing devices, are arranged in a prestressed manner, wherein the prestress acts due to at least one welded connection (S1, S2, S3) between a fastening element material of a second fastening element (36; 131) and a bearing device material of one of the two bearing devices (21, 25; 121, 125), wherein the welded connection (S1, S2, S3) is produced in particular by introducing a prestressing force (Fv) according to a method according to one of claims 1 to 10.

12. Electric drive component according to claim 11, characterized in that the at least one welded connection (S1, S2, S3) has at least one weld seam (41) which forms a circular ring segment (42) which extends in particular 20° to 90°, preferably 40°, along a circular ring on one of the two bearing devices (21, 25; 121, 125).

13. Electric drive component according to claim 12, characterized in that the at least one weld seam (41) is designed as a spot weld connection consisting of a plurality of weld points arranged in a row or of a plurality of weld points spaced apart from one another.

14. Electric drive component according to claim 12 or 13, characterized in that the weld seam (41) has a concave seam surface.

15. Electric drive component according to one of claims 12 to 14, characterized in that the weld seam (41) has a weld seam width of less than 0.5 mm, in particular a weld seam width of less than 0.25 mm.

16. Manufacturing device (200) for producing an electric drive component (20; 120) with at least two prestressed bearing devices (21, 25; 121, 125), comprising a holding device (210) for holding at least one fastening element (36; 131), with at least one means (211) for applying a prestressing force (Fv) to one of the two bearing devices (21, 25; 121, 125) and a device for creating at least one welded connection (S1, S2, S3) by fusion welding with radiation.

17. Electric drive (300) with an electric drive component (20; 120) according to claims 11 to 15, wherein the electric drive component (20; 120) comprises at least two bearing devices (21, 25; 121, 125) and a prestress acts on the two bearing devices (21, 25; 121, 125), wherein the prestress acts due to at least one welded connection (S1, S2, S3) between a fastening element material of the second fastening element (36; 131) and a bearing device material of one of the two bearing devices (21, 25; 121, 125), which are welded under an acting prestressing force (Fv).

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