Method for manufacturing an electric motor

Abstract

Method for producing an electric motor (1) with a housing (2) and a bearing plate (3), wherein the housing (2) has a radial casing region (4) and a base region (5), the base region (5) is provided with a recess (6), and the bearing plate (3) is connected to the base region (5) of the housing (2) by a clamping connection, characterized by the following method steps: a) providing a bearing plate (3), a housing (2), a clamping disc, and a mounting device, b) inserting the bearing plate (3) into the mounting device, c) placing the housing (2) onto the bearing plate (3), wherein a bearing receptacle (10) with a clamping region (12) extends through the recess (6), d) feeding the clamping disc (7) to a clamping surface (12) of the bearing plate (3), pressing the clamping disc (7) onto the clamping surface (12) of the bearing receptacle (10) with the aid of the mounting device until it abuts. Clamping disc (7) to the base area (5),e) Further pressing of the clamping disc (7) until a cavity formed by a step (8) in the base area (5) is significantly reduced, f) Assembly of further engine components, g) Removal from the assembly device.,

Description

[0001] The invention relates to a method for producing an electric motor (1) with a housing (2) and a bearing plate (3), wherein the housing (2) has a radial shell region (4) and a base region (5).

[0002] Electric motors are often connected to components such as pumps or gearboxes by screwing or by forming a positive connection. Welding is another option. The use of screws requires considerable space. Welding processes are complex, and forming can lead to undesirable deformations.

[0003] US 2012 / 0 019 080 A1 discloses an electric motor assembly having a stator assembly and a rotor assembly extending through the stator assembly. A first end cap is located adjacent a first end of the stator assembly and includes a bearing insert supporting a bearing at the first end for receiving one end of a rotor shaft. A second end cap is located adjacent a second end of the stator assembly. An end bell is formed separately from the second end cap and positioned within the second end cap. The end bell supports a bearing for a second end of the rotor shaft. An overmolded material extends through the stator assembly. The overmoldable material may form the first end cap supporting the bearing insert therein and extends within the second end cap and substantially fills an annular space.

[0004] From US 2004 / 0 183 386 A1 an electric motor with a housing and a bearing shield is known, wherein the housing has a shell region and a base region and the base region is connected to the bearing shield.

[0005] JP 2003-139151 A discloses a bearing device comprising a housing 40 having a bearing holding portion 41, the bearing 42 housed in the bearing holding portion 41, a plate 44 for holding the bearing 42 at one end, and a rotating shaft 23 mounted with a thrust washer 24 and rotatably supported by the bearings 42, 52. The plate 44 has a bearing pressing portion 44c abutting the bearing 42 and a sliding portion 44e slidably abutting the thrust washer 24.

[0006] From DE 10 2015 213 021 A1 is an electric motor with a housing and a rotor which is mounted in the housing via a fixed / loose bearing, wherein a deep groove ball bearing with an inner ring and an outer ring is provided as the fixed bearing and the outer ring of the fixed bearing is elastically clamped in the housing by means of a spring steel disc.

[0007] DE 10 2017 203 261 A1 discloses a method for manufacturing an electric machine of a motor vehicle, in particular a steering motor. A housing with a stator is provided, and a rotor is inserted into the housing. A bearing plate with a bearing for rotatably supporting the rotor is placed on the housing, and a variable characterizing the position of the rotor relative to the stator is determined. The bearing plate is displaced relative to the housing such that a deviation between a target value and the characteristic variable is less than or equal to a limit value, and the bearing plate is attached to the housing.

[0008] From DE 42 01 373 A1, an O-ring seal for a geared motor is known, which is located between a motor unit and a reduction gear head of a geared motor. An O-ring holder, which holds an O-ring in place, is defined by a flange surface of a flange of a bracket installed in a recess of a frame of the motor unit and also by a guide groove formed on an outer side of a circular hub. The flange has a thickness that is smaller by a distance than the depth of the recess. As a result of the distance difference and the guide groove, the O-ring cannot slip off or become jammed when the reduction gear head is coupled to the motor unit.

[0009] JP 2007-082 342 A discloses a method for producing an electric motor with a housing 20b and a bearing plate 20a, wherein the housing has a radial shell region and a base region, the method comprising the following method steps: providing a bearing plate, a housing and a mounting device; inserting the bearing plate into the mounting device; placing the housing on the bearing plate, wherein a bearing receptacle with a clamping region extends through the recess; mounting further motor components.

[0010] The object of the invention is to provide an easy-to-manufacture, economical and reliable mechanical connection in an electric motor that requires little space.

[0011] This object is achieved according to the invention by the features of method claim 1 with the following method steps: a) providing a bearing plate (3), a housing (2), a clamping disk and a mounting device, b) inserting the bearing plate (3) into the mounting device, c) placing the housing (2) on the bearing plate (3), wherein a bearing receptacle (10) with a clamping surface (12) extends through the recess (6), d) feeding the clamping disk (7) to a clamping surface (12) of the bearing plate (3), pressing the clamping disk (7) with the aid of the mounting device onto the clamping surface (12) of the bearing receptacle (10) until the clamping disk (7) abuts the base region (5), e) further pressing the clamping disk (7) until a cavity formed by a step (8) in the base region (5) is significantly reduced in size, f) mounting further motor components, g) removing it from the mounting device.

[0012] Further developments of the invention are presented in the subclaims.

[0013] Other motor components can be: a stator (17), a rotor (30), a motor bearing shield (14) and an electronics housing.

[0014] Between assembly steps b) and c), a seal (13) is usually inserted into a seal receiving groove (31) of the bearing plate (3) and / or a ball bearing (18) is inserted into a bearing receptacle (10) of the bearing plate (3).

[0015] It is further proposed that the mounting device engages a pressure ring (39) of the clamping disc (7).

[0016] The object is also achieved by an electric motor (1) according to the method according to claims 1 to 4, with a housing (2) and a bearing plate (3), wherein the housing (2) has a radial shell region (4) and a base region (5), the base region (5) is provided with a recess (6) and the bearing plate (3) is connected to the base region (5) of the housing (2) by a clamping connection.

[0017] Since the housing (2) and the bearing plate (3) can be connected to each other by a clamping connection, particularly simple assembly with short cycle times is possible.

[0018] According to the invention, the base region (5) has a central recess (6). The recess (6) in the base region (5) allows the bearing plate (3) to extend partially through the housing. This provides a simple way of establishing the clamping connection by using the area of ​​the bearing plate (3) that projects through the base region (5) as a clamping surface. In particular, the clamping connection can be realized by a single clamping surface (12), which results in an even force distribution of the mechanical connection between the housing (2) and the bearing plate (3).

[0019] A uniform force distribution can also be achieved by providing several recesses distributed across the base of the housing, with a corresponding number of protruding portions of the bearing plate extending into the housing. This generally results in a smaller clamping surface. This is compensated for by a larger number of clamping points. Depending on the number and design of the clamping points, greater holding forces can also be achieved.

[0020] A portion of the bearing plate is provided to extend through the recess(es). This allows a clamping disc (7) to rest on the bearing plate (3) on one side and the base area (5) on the other, thus pressing the base area (5) against the bearing plate (3).

[0021] To achieve a more secure and permanent mechanical connection, the base area (5) is provided with a step (8). This allows for a greater spring deflection, which prevents the clamping force from decreasing when the clamping tongues are incorporated into the clamping surface.

[0022] The clamping disc can have a central or multiple decentrally arranged clamping areas with clamping tongues forming the clamping area. The clamping tongues are each arranged around a passage.

[0023] A second embodiment not according to the invention provides that the housing (2) is directly interlocked with the bearing plate (3). Thus, no additional component is required. This solution is particularly economical and reliable to implement, but it requires a housing material with resilient properties.

[0024] To implement the second embodiment, the recess (6) should be radially slotted or cut.

[0025] According to a particularly preferred embodiment, the bearing plate (3) should have a substantially hollow-cylindrical bearing support (10) that serves as a clamping surface (12) outside a bearing support space (11). This geometry is already present in many applications, so that existing parts can possibly be used.

[0026] According to an advantageous development of the invention, the bearing receiving space (11) is axially covered by the base region (5) of the housing (2). As a result, the bearing (18) is held in a form-fitting manner, on the one hand, in the bearing receptacle (10) of the bearing shield (3) and, on the other hand, by the base region (5). The region serving as the bearing receiving surface is drawn axially toward the motor interior (46) relative to the remaining base region (5) in order to enable an axial overlap between the housing (2) and the bearing shield (3).

[0027] To still be able to mount a clamping disc, it is further provided that the base area (5) is integral with a bearing retaining ring (43) by means of bearing retaining spokes (44), and clamping tongues (41) of a clamping disc (7) are accommodated in spaces (47) between the bearing retaining spokes (44). The spaces (47) are designed such that there is always play between the bearing retaining spokes (44) and the clamping tongues (41). This ensures that the clamping tongues (41) can fully exert their clamping effect. The bearing retaining spokes are produced by punching out the spaces (47).

[0028] One possible application is pumps (20). In this case, it is proposed that the bearing plate (3) form a wall of the pump housing. This allows for a smaller number of parts.

[0029] Especially in pump applications, high sealing requirements must be met. Therefore, it is advisable to provide a seal (13) between the bearing plate (3) and the housing (2). The clamp connection causes the seal to fit tightly against the mating parts, thereby deforming them. This results in reliable sealing of this housing area.

[0030] In order to keep the number of parts as low as possible, the bearing plate (3) should fulfil an interface function.

[0031] Furthermore, it is provided that a positive connection is present between the housing (2) and the bearing plate (3), wherein the bearing plate (3) has a recess (32) into which a housing projection (33) of the housing (2) engages. This allows for correct angular orientation and anti-rotation protection. The housing projection is produced from the housing base 5 by forming. Alternatively, a projection on the bearing plate (3) and a recess or recess on the housing (2) would also be possible.

[0032] In the manufacture of electric motors, it is very important to create reliable and consistently strong mechanical connections. This is ensured by ensuring that the inner diameter of the clamping disc (7) at the ends of the clamping tongues (41) is smaller than the outer diameter of the clamping surface (12) in the unassembled state under all tolerance conditions.

[0033] When assembled, the clamping tongues (41) should be slightly angled by an angle α relative to a normal plane to the motor axis, opposite to the joining direction. If a force is applied against the assembly direction, the angle α would then first have to be reduced to 0. However, this is generally not possible without causing damage due to the diameter ratios between the clamping disc (7) and the clamping surface (12).

[0034] Sufficient strength between the clamping disc (7) and the clamping surface (12) is also ensured by the angle α being smaller than the arctangent of a sliding friction coefficient between the clamping disc (7) and the clamping surface (12).

[0035] Embodiments of the invention are explained in more detail below with reference to the drawings. They show: Fig. 1 a sectional view of an electric motor, Fig. 2 a sectional view of a housing connection, Fig. 3 a spatial representation of the housing connection, Fig. 4 a clamping disc, Fig. 5 a second embodiment of a housing not according to the invention, Fig. 6 a spatial representation of the housing from Fig. 5, Fig. 7 is a sectional view of an electric motor according to a third embodiment, Fig. 8 a first spatial representation of a housing connection of the third embodiment, Fig. 9 a second spatial representation of the housing connection of the third embodiment, Fig. 10 is a sectional view of the housing connection of the third embodiment, Fig. 11 a spatial and a sectional view of the housing according to the third embodiment and Fig. 12 a third embodiment of a clamping disc.

[0036] Note: Reference symbols with an index and corresponding reference symbols without an index denote details of the same name in the drawings and the drawing description. This refers to the use in a different embodiment, the prior art, and / or the detail is a variant. For the sake of simplicity, the claims, the introduction to the description, the list of reference symbols, and the summary contain only reference symbols without an index.

[0037] Fig. 1 shows a sectional view of an electric motor 1, with a housing 2, a bearing shield 3, which is part of a pump 20, a motor bearing shield 14, an electronics housing 15, a housing cover 16, a wound stator 17 fastened in the housing 2, a bearing 18, a motor bearing 19 and a rotor 30 rotatably mounted therein. The motor bearing shield 14 accommodates the ball bearing 19. The motor interior 46 is delimited by the bearing shield 3, the housing 2 and the electronics housing 15. The bearing shield 3 has a shaft passage 29, a seal receiving groove 31, a recess 32 and a bearing receptacle 10 for the bearing 18. The recess 32 serves to accommodate a housing projection 33. This serves as an orientation and / or anti-twist means. On its outer diameter, the bearing holder 10 has a clamping surface 12 to which a clamping disc 7 is clamped.The clamping disc 7 rests against a base area 5 of the housing and holds the position plate 3 in contact with it on the opposite side of the base area 5. A housing projection 33 in the base area 5 of the housing 2 serves as an anti-twist device. The bearing holder 10 extends through a central recess 6 of the housing 2 into its interior. A printed circuit board 22 is accommodated between the electronics housing 15 and the housing cover 16 and can be connected to an external voltage source via a plug 25. A magnetic sensor 24 is arranged on the printed circuit board 22 and interacts with a magnetic encoder 23. The magnetic encoder 23 is accommodated in a holding sleeve 34 which is pressed onto a shaft end of the shaft 21. The housing 2 is screwed to the electronics housing 15. For this purpose, the housing 2 has a flange 48 with radial extensions 35 in which screw eyes 36 (see . Fig. 2). The bearing plate 3 and the pump housing cover are pinned and screwed together, and sealed by a pump housing seal 37. Between the bearing plate 3 and the pump housing cover is a gerotor pump consisting of a pinion gear 27 and a ring gear 28. The pinion gear 27 is positively driven by the shaft 21 and engages with the ring gear.

[0038] Fig. Figure 2 shows a sectional view of the housing connection between the bearing shield 3 and the housing 2 by means of the clamping disc 7, which is clamped onto the clamping surface 12 of the bearing seat 10 and presses the bottom area 5 of the housing 2 against the bearing shield 3. The bottom area 5 has a step 8. The housing 2 is made of a steel material, while the bearing shield 3 is made of a softer metal. The bearing seat 10 radially encloses a bearing receiving space 11 for receiving a bearing. On the side opposite the bearing seat 10, the bearing shield 3 forms a pump receiving space 45. To seal between the housing 2 and the bearing shield 3, the latter is provided with a seal receiving groove 31, in which a seal 13 in the form of a ring cord seal is arranged. The force of the clamping disc 7 causes the seal 13 to be compressed. The housing projection 33 is also shown engaging with the recess 32.The outer surface 4 of the housing 2 has different diameters. The flange 48, the radial extensions 35, and the screw lugs are also visible.

[0039] Fig. 3 shows a three-dimensional representation of the housing connection, with the housing 2, the bearing plate 3, the clamping disc 7, and the seal 13. The clamping disc 7 is clamped onto the clamping surface 12 of the bearing support 10. Also shown are the bearing support space 11, the central recess 6, the shaft passage 29, the recess 32, the housing projection 33, the flange 48, the radial extensions 35, and the screw eyes 36.

[0040] Fig. 4 shows a clamping disc 7, with a stiffening ring 38, a pressure ring 39 and a multi-slotted spring ring 40. Clamping tongues 41 are formed by the slots 42. The spring tongues are angled relative to the pressure ring.

[0041] Fig. Figure 5 shows a second embodiment of a housing 2a, not according to the invention, with a shell region 4a and a base region 5a, which has a central recess 6a on the inside. For connection to the bearing plate (not shown here), no additional clamping disc is required because the housing 2a itself has the geometry required for assembly. In order to achieve a sufficient clamping effect, the central recess 6a (see Fig. 6) are provided with radial slots 42a, forming clamping tongues 41a. These clamping tongues 41a can engage with a clamping area of ​​a bearing plate or other attachment pressed through the recess 6a. Radial extensions 35 with screw eyes 36 are located on a flange 48, which serve for mounting an electronics housing or housing cover. A step 8a can be seen in the base area 5a, which enables more secure clamping of the clamping tongues 41a.

[0042] Fig. 6 shows a spatial representation of the housing 2a from Fig. 5, with the shell area 4a, the base area 5a, the step 8a, the flange 48, the radial extensions 35, the screw eyes 36, the clamping tongues 41a and radial slots 42a.

[0043] Fig. Figure 7 shows a sectional view of an electric motor 1b according to a third embodiment, with a housing 2b, consisting of a shell region 4b and a base region 5b, a bearing shield 3b, a pump housing cover 26b, an electronics housing 15b, a housing cover 16b, a rotor 30b, and a stator 17b. The rotor 30b is fastened to a shaft 21b, which is rotatably mounted in a bearing 18b and a motor bearing 19b. The motor bearing is accommodated in a motor bearing shield. The bearing shield 18b has a shaft passage 29b through which the shaft 21b projects into a pump receiving space 45b, and a bearing receptacle 10b, which extends through the base region 5b of the housing 2b toward the motor interior 46b. The electronics housing 15b encloses a printed circuit board 22b.The bottom area 5b of the housing 2b is integral with a bearing retaining ring 43 via bearing retaining spokes 44, wherein the bearing retaining spokes 44 nestle against the bearing receptacle 10b and the bearing retaining ring rests axially against the bearing receptacle 10b.

[0044] Fig. Figure 8 shows a first spatial representation of a housing connection of the third embodiment, with the bearing plate 3b and the housing 2b. The housing 2b has a shell region 4b and a base region 5b (partially hidden). Bearing retaining spokes 44b are connected to the base region 5b, and a bearing retaining ring 43b is connected to the bearing retaining spokes, which is oriented parallel to the housing base 5b. Furthermore, a clamping disc 7b can be seen, which has clamping tongues 41b arranged in spaces 47b between the bearing retaining spokes 44b. The clamping tongues 41b are clamped to the bearing receptacle 10b (see Fig. 7). A pressure ring 39b of the clamping disc 7b rests against the housing base 5b. A bearing 18b is positively received between the bearing retaining ring 43b and the bearing plate 3b.

[0045] Fig. Figure 9 shows a second spatial representation of the housing connection of the third embodiment, with the housing 2b, the shell region 4b, the base region 5b, the clamping disc 7b, the clamping tongues 41b, the bearing plate 3b, the bearing seat 10b, the bearing 18b, the bearing retaining spokes 44b, the bearing retaining ring 43b, and a seal 13b between the housing 2b and the bearing plate 3b. Furthermore, a flange 48b, radial extensions 35, and screw eyes 36 can be seen.

[0046] Fig. 10 shows a sectional view of the housing connection of the third embodiment with the housing 2b, the shell region 4b, the base region 5b, the flange 48b, the radial extensions 35b, the screw-on eyes 36b, the clamping disc 7b, the clamping tongues 41b, the bearing shield 3b, the bearing seat 10b, the bearing 18b, the bearing retaining spokes 44b, the bearing retaining ring 43b, and a seal 13b between the housing 2b and the bearing shield 3b. The bearing seat 10b is hollow-cylindrical, with its outer surface serving as a clamping surface 12b for the clamping disc 7b.

[0047] Fig. 11 shows a spatial and a sectional view of the housing 2b according to the third embodiment, with the shell region 4b, the base region 5b, the bearing retaining ring 43b, the bearing retaining spokes 44b, the step 8b, the flange 48b, the radial extensions 35b and the screw eyes 36b.

[0048] Fig. Figure 12 shows a third embodiment of a clamping disc 7b, with a stiffening ring 38b, a pressure ring 39b and radially inwardly adjoining clamping tongues 41b. The clamping tongues 41b are provided with slots 42b that are wider than in the first embodiment, in order to be able to be mounted over the position-holding spokes (see Fig. 9). The totality of all spring tongues 41b forms a spring ring 40b. List of reference symbols 1 electric motor 2 housings 3 bearing plate 4 Sheath area 5 Floor area 6 Recess 7 clamping disc 8th level 9 Housing slot 10 Bearing intake 11 Storage room 12 clamping surface 13 Seal 14 Motor bearing plate 15 electronics housings 16 Housing cover 17 Stator 18 camps 19 engine mounts 20 pump 21 Wave 22 circuit board 23 magnetic encoders 24 Magnetic sensor 25 plugs 26 Pump housing cover 27 Pinion wheel 28 ring gear 29 Wave passage 30 rotors 31 Seal receiving groove 32 Return 33 Housing projection 34 retaining sleeve 35 extension 36 screw-on eye 37 Pump housing seal 38 stiffening ring 39 Pressure ring 40 spring washer 41 clamping tongues 42 slot 43 Bearing retaining ring 44 bearing holding spoke 45 Pump accommodation space 46 Engine compartment 47 space 48 flange

Claims

[1] Method for producing an electric motor (1) with a housing (2) and a bearing plate (3), wherein the housing (2) has a radial shell region (4) and a base region (5), the base region (5) is provided with a recess (6) and the bearing plate (3) is connected to the base region (5) of the housing (2) by a clamping connection, characterized bythe following method steps: a) providing a bearing plate (3), a housing (2), a clamping disk and a mounting device, b) inserting the bearing plate (3) into the mounting device, c) placing the housing (2) on the bearing plate (3), whereby a bearing receptacle (10) with a clamping area (12) extends through the recess (6), d) feeding the clamping disk (7) to a clamping surface (12) of the bearing plate (3), pressing the clamping disk (7) with the aid of the mounting device onto the clamping surface (12) of the bearing receptacle (10) until the clamping disk (7) abuts the base area (5), e) further pressing the clamping disk (7) until a cavity formed by a step (8) in the base area (5) is significantly reduced in size, f) mounting further motor components, g) removing it from the mounting device. [2] Method according to claim 1 characterized bythat between assembly steps b) and c) a seal (13) is inserted into a seal receiving groove (31) of the bearing plate (3). [3] Method according to claim 1 or 2, characterized by that a ball bearing (18) is inserted between assembly steps b) and c). [4] Method according to claim 1, 2 or 3, characterized by that the mounting device engages a pressure ring (39) of the clamping disc (7). [5] Electric motor (1) according to the method according to one of claims 1 to 4, with a housing (2) and a bearing plate (3), wherein the housing (2) has a radial casing region (4) and a base region (5) and the base region (5) is connected to the bearing plate (3) by a clamping connection, wherein the base region (5) has a central recess (6), through which a region of the bearing plate (3) extends, and a step (8), and wherein a clamping disc (7) is supported on the one hand on the bearing plate (3) and on the other hand on the base region (5) and in this way presses the base region (5) against the bearing plate (3). [6] Electric motor according to claim 5, characterized by that the base area (5) has a plurality of recesses (6) which are distributed over the base area (5). [7] Electric motor according to claim 5, characterized bythat the clamping disc (7) has a central or several decentrally arranged clamping areas with clamping tongues (41) forming the clamping area. [8] Electric motor according to claim 5 or 6, characterized by that the housing (2) is directly connected to the bearing plate (3). [9] Electric motor according to at least one of the preceding claims, characterized by that the recess (6) is radially slotted or cut. [10] Electric motor according to at least one of the preceding claims, characterized by that the bearing plate (3) has a substantially hollow-cylindrical bearing receptacle (10) which serves as a clamping surface (12) outside a bearing receptacle space (11). [11] Electric motor according to claim 10, characterized by that the bearing receiving space (11) is axially covered by the base area (5) of the housing (2). [12] Electric motor according to claim 11, characterized bythat the base region (5) is integral with a bearing retaining ring (43) by means of bearing retaining spokes (44) and clamping tongues (41) of a clamping disc (7) are received in spaces (47) between the bearing retaining spokes (44). [13] Electric motor according to at least one of the preceding claims, characterized by that the bearing shield (3) forms a wall of an attachment, in particular a pump housing or a gear housing. [14] Electric motor according to at least one of the preceding claims, characterized by that the bearing plate (3) fulfils an interface function. [15] Electric motor according to at least one of the preceding claims, characterized by that there is a positive connection between the housing (2) and the bearing plate (3). [16] Electric motor according to at least one of the preceding claims, characterized bythat a seal (13) is arranged between the bearing plate (3) and the housing (2), wherein the clamping connection acts on the seal (13). [17] Electric motor according to at least one of the preceding claims, characterized by that the inner diameter of the clamping disc (7) at the ends of the clamping tongues (41) in the unassembled state is smaller than the outer diameter of the clamping surface (12) under all tolerance conditions. [18] Electric motor according to at least one of the preceding claims, characterized by that the clamping tongues (41) are slightly angled by an angle α relative to a normal plane to the motor axis, opposite to the joining direction. [19] Electric motor according to claim 18, characterized by that the angle α is smaller than the arctangent of a sliding friction coefficient between the clamping disc (7) and the clamping surface (12).

Images