Electric motor with fan hood and rotor shaft mounted to rotate relative to the fan hood and angle sensor

Description

[0001] The invention relates to an electric motor with a fan hood and a rotor shaft rotatably mounted relative to the fan hood and an angle sensor.

[0002] It is generally known that an angle sensor can be arranged on an electric motor to detect the angular position of the rotor shaft.

[0003] From the EP 2 113 989 A1 The closest state of the art is a torque support for attaching the housing of a rotary encoder to an electric motor.

[0004] Out of the product data sheet "Stator coupling / torque support Model series ZMS58" from TWK-Elektronik GmbH, published on 16.01.2017 (XP 055769987), Circumferentially meandering webs of a torque support are known.

[0005] From the DE 10 2012 024811 A1 is a known electric motor with a fan cover and sensor.

[0006] From the DE 10 2012 004459 A1 A drive with torque support for axially and radially less stiff than circumferentially stiff mounting of the housing of an angle sensor to a fan hood grille of an electric motor is known.

[0007] The invention is therefore based on the objective of further developing an electric motor, whereby the production should be simple and cost-effective.

[0008] According to the invention, the problem is solved in the electric motor according to the features specified in claim 1.

[0009] An advantage of this design is that tolerances can be compensated for using the torque support, while still achieving a rigid connection in the circumferential direction. This ensures that the angle sensor housing is connected to the fan shroud with maximum torsional rigidity, thus dissipating reaction torques.

[0010] In both axial and radial directions, tolerances of components can be easily compensated using the torque support. This makes it easy to manufacture and assemble cost-effective components without special effort.

[0011] According to the inventionThe housing is connected to an inner ring of the torque support by means of a first and a second connection area of ​​the torque support. An advantage of this is that a flat contact surface of the inner ring is achieved, thus aligning the connection plane with the housing of the angle sensor.

[0012] According to the invention The torque support features tab areas, particularly those projecting radially outwards, to which the fan shroud is connected. An advantage of this design is that it achieves a flat contact surface with the fan shroud, thus aligning the corresponding connection plane with the shroud, especially with the fan grille. Manufacturing tolerances can be compensated for using the torque support.

[0013] According to the inventionEach tab section is connected to the inner ring by means of webs. An advantage of this design is that the torque support has tab sections with a larger radial spacing than the inner ring, allowing the webs to bridge this radial gap. Preferably, each web is not connected to the inner ring at the same circumferential angle as it is connected to the respective tab section. This allows for a more efficient arrangement of the meander. From the connection point, the meander begins with its first loop tangentially or circumferentially and, after several loops, terminates tangentially or circumferentially in one of the tab sections.

[0014] In an advantageous embodiment, the respective tab area is pressed against the fan housing by means of a fastening element, in particular a screw. It is advantageous that the fastening element protrudes through a recess in the tab area and through a grille opening in the fan housing's grille, and when a nut is screwed on, exerts pressure from both sides, thus pressing the tab area against the fan housing and securing it in a form-fit manner.

[0015] In a preferred embodiment, the inner ring and / or the connecting areas are pressed against the housing of the angle sensor by a screw. The advantage here is that simple fastening is achievable.

[0016] In an advantageous embodiment, the tab areas are radially spaced from the inner ring and the connection areas, with the radial direction being relative to the axis of rotation of the rotor shaft. It is advantageous that the meander, with its first and last loops, can be formed tangentially or circumferentially.

[0017] In an advantageous embodiment, the respective connection area is spaced circumferentially from the respective tab area. It is advantageous that the meander, with its first and last loop, opens tangentially or circumferentially into the connection area or the tab area, respectively.

[0018] In an advantageous embodiment, the radial spacing area covered by the web, relative to the axis of rotation of the shaft, is arranged between or overlaps the radial spacing area covered by the lug areas and the radial spacing area covered by the connecting areas. It is advantageous that the web performs the connection. Preferably, two of the webs each terminate in a respective lug area and at their other end in one of the connecting areas. The webs are spaced apart from each other in the circumferential direction.

[0019] In an advantageous embodiment, the rotor shaft is rotatably mounted by means of a bearing received in a bearing flange of the electric motor, wherein the fan housing is connected to the bearing flange, in particular attached to the bearing flange. It is advantageous that the reaction torque of the angle sensor housing can be dissipated to the bearing flange via the torque arm and the fan housing. In contrast, the rotor shaft of the electric motor is connected to the shaft of the angle sensor.

[0020] In an advantageous embodiment, the angle sensor has a shaft that is rotatable relative to the housing of the angle sensor and is non-rotatably connected to the rotor shaft. The advantage here is that the angular position of the rotor shaft can be detected.

[0021] In an advantageous embodiment, the torque support is designed as a flat stamped sheet, with the normal of the plane containing the stamped sheet being aligned parallel to the axis of rotation of the rotor shaft. An advantage of this design is that high stiffness can be achieved in the circumferential direction, i.e., during rotation within the plane.

[0022] In an advantageous embodiment, the tab areas lie parallel to the fan grille of the fan housing. An advantage of this is that a circumferentially rigid design can be achieved, and the torsional stiffness of the torque support can also be combined with a correspondingly torsionally stiff fan housing.

[0023] In a preferred embodiment, the housing of the angle sensor is arranged on the side of the fan shroud facing away from the bearing flange. It is advantageous that the angle sensor protrudes on the side facing away from the rotor shaft.

[0024] Further advantages arise from the dependent claims. Within the scope of protection defined by the independent claim, the person skilled in the art discovers further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures, particularly from the problem statement and / or the problem arising from a comparison with the prior art.

[0025] The invention will now be explained in more detail with reference to schematic illustrations: In the Figure 1 A sectional view through an electric motor according to the invention is shown, which has an angle sensor for detecting the rotor position of the rotor shaft of the electric motor. In the Figure 2 A torque support, connected on one side to the housing 2 of the angle sensor and on the other side to a fan cover 9 of the electric motor, is shown in an oblique view. In the Figure 3 is a to Figure 2A proper top view of the torque support is shown. In the Figure 4 The exploded electric motor is shown in an oblique view. In the Figure 5 The angle sensor and the fan cover 9 are shown exploded from the housing part 7 of the electric motor, with the torque support 1 being connected to the fan cover 9 in a rotationally fixed manner by means of screws 42.

[0026] As shown in the figures, the electric motor according to the invention has a rotatably mounted rotor shaft 5, onto which an active part 4 is attached and connected in a rotationally fixed manner, in particular wherein the active part 4 has a squirrel cage or permanent magnets depending on the design of the electric motor as an asynchronous motor or synchronous motor.

[0027] At least one of the bearings rotatably supporting the rotor shaft 5 is received in a bearing flange 11, which is detachably, but in particular rotationally fixed, connected to a housing part 7. A stator winding 6 is arranged radially inside the housing part 7 and rotationally fixed to the housing part 7.

[0028] On the side of the bearing flange 11 facing away from the stator winding 6, a fan hood 9 is attached to the bearing flange 11, which radially surrounds a fan 8 that is connected to the rotor shaft 5 in a rotationally fixed manner.

[0029] The fan hood 9 has a fan grille, specifically continuous openings arranged in a grille, so that the airflow conveyed by the fan can pass through the fan grille. On the other hand, the fan hood 9 performs a protective function by preventing people from touching rotatably mounted parts.

[0030] The fan hood 9 is either made of plastic as a plastic injection molded part or of metal sheet as a stamped and bent part.

[0031] An angle sensor for detecting the angular position of the rotor shaft 5 has a shaft 3 which is rotatable relative to a housing 2 of the angle sensor, in particular mounted to be rotatable relative to a housing 2 of the angle sensor.

[0032] The housing 2 of the angle sensor is connected to a torque support 1, which is connected to the fan cover 9.

[0033] This torque support 1 is designed such that the torque support 1 has a higher stiffness against a rotation directed circumferentially with respect to the rotor shaft 5 between housing part 2 of the angle sensor and fan hood 9, in particular against a torsional rotation, than against an axial displacement and also against a radial displacement.

[0034] In this way, manufacturing tolerances of the components, for example the fan housing together with the bearing flange 11 and / or the rotor shaft 5 together with the shaft 3 of the angle sensor, can be compensated for. In particular, tolerances in axial extension or in the axial direction lead to an axial mispositioning of the housing 2, which, however, can be compensated for by the torque support 1, which has little rigidity in the axial direction.

[0035] The torque transmission is not affected by this, since the torsional stiffness of the torque support 1 is very high and thus the housing 2 is sufficiently rotationally rigid connected to the bearing flange via the fan cover 9.

[0036] The shaft 3 of the angle sensor is connected to the rotor shaft 5 in a rotationally fixed manner. Preferably, a force-fit connection such as a spreading shaft connection or a conical shaft connection is used for this purpose.

[0037] The angle sensor generates a sensor signal that encodes the angular position of the rotor shaft 5 relative to the housing part 7. The angle sensor is implemented according to either a magnetic or an optical operating principle.

[0038] The bearing of the rotor shaft 5, which is received in the bearing flange 11, is preferably designed as a fixed bearing. A design as a floating bearing is also possible, since the torque support 1 couples the housing of the angle sensor to the fan cover 9.

[0039] The torque support 1 rests against a preferably flat fan grille of the fan hood 9 and is fixed to the fan hood 9 in a rotationally secure manner by at least one fastening means 10, in particular a screw with nut.

[0040] A shaft seal is mounted axially between housing 2 and the fixed bearing in the bearing flange, sealing the bearing flange towards the rotor shaft 5. For this purpose, the sealing lip of the shaft seal rests against and contacts the rotor shaft 5.

[0041] The torque support 1 has tab areas 22 projecting radially outwards at its radial outer edge, through which one of the fastening means 10, in particular a screw, is guided, which also projects through the grille of the fan hood 9, in particular so that the screw head of the fastening means 10, which is preferably designed as a screw, and a nut screwed onto a threaded area of ​​the fastening means 10 press the torque support 1 against the fan hood 9.

[0042] The torque support 1 has an inner ring 23 at its radially inner end region, which is connected to the tab regions 22 via preferably four meandering webs 24.

[0043] Here, in the Figure 2 and 3 In the preferred embodiment shown, two of the webs 24 are connected to the inner ring 23 in a first connection area that covers a first circumferential angle area, wherein an axially through-hole 25 is arranged in this first connection area through which a further fastening element is passed, which connects the torque support 1 to the housing 2 of the angle sensor, in particular pressing it against the housing. The further fastening element is preferably again designed as a screw part, the screw head of which, when screwed into an axially directed threaded bore of the housing 2, presses the torque support 1 against the housing 2.

[0044] Similarly, a second connection area is formed on the inner ring 23, diametrically opposite the first connection area, which covers a second circumferential angle area. A second axially through-hole 25 is arranged in this second connection area, through which a second further fastening element is passed. This second fastening element also connects the torque support 1 to the housing 2 of the angle sensor, in particular pressing it against the housing. The second further fastening element is preferably again designed as a screw element, the screw head of which, when screwed into a further axially directed threaded bore of the housing 2, presses the torque support 1 against the housing 2.

[0045] Two of the webs 24 are connected with their radially inner end region to the first connection region and with their radially outer connection region to a first of the tab regions 22.

[0046] Two further of the webs 24 are connected with their radially inner end region to the second connection region and with their radially outer connection region to a second of the tab regions 22.

[0047] The first tab area 22 is arranged diametrically opposite the second tab area 22, in particular, essentially spaced about 180° apart in the circumferential direction.

[0048] The meandering design of the respective web 24 is arranged within the plane defined by the torque support 1, which is preferably designed as a stamped sheet metal part.

[0049] The meandering area is designed such that, with increasing radial distance, a first of the two webs 24 initially has a circumferential angle increasing up to a maximum value and then has a circumferential angle decreasing down to a minimum value, whereupon the circumferential angle then increases again until it reaches the circumferential angle range covered by the tab area 22.

[0050] In further embodiments according to the invention, the meandering course of the web 24 varies more frequently with increasing radial distance to the axis of rotation of the rotor shaft and accordingly reaches the maximum or minimum value more frequently.

[0051] As in Figure 2 and 3 The meandering course of the second web 24 of the two webs 24 is shown in the circumferential direction in a mirror symmetrical way to the plane containing the axis of rotation of the rotor shaft and the center point of the recess 26 and / or the center of gravity of the first tab area 22.

[0052] Preferably, the two other webs 24 are also designed to be mirror-symmetrical to the aforementioned webs 24.

[0053] Since the torque support 1 is manufactured as a flat and planar stamped sheet metal part, the respective meander, i.e., the respective meandered web 24, lies in a plane whose normal direction is aligned parallel to the axis of rotation of the rotor shaft, and the torsional stiffness with respect to torsion relative to the axis of rotation is very high. Therefore, angle detection with the angle sensor can be performed with minimal error.

[0054] In the axial direction, deflection of the tab areas 22 relative to the axial position of the inner ring 23 is possible with minimal force, since the torque support 1 does not exhibit high stiffness with respect to such deflections. Thus, manufacturing tolerances can be compensated for without impairing the angle detection.

[0055] Likewise, radial deviations due to elastic deflection of the tab areas 22 relative to the inner ring 23 can be accommodated.

[0056] The webs 24 are preferably spaced regularly apart from each other in the circumferential direction.

[0057] Preferably, the inner ring 23 rests against the housing 2 of the angle sensor.

[0058] Each bridge 24 covers, in particular with its meandering course, a circumferential angle range which covers more than 60° and in particular extends less than 90°.

[0059] There is therefore an angular distance of more than 60° between the maximum and minimum values, with the angular distance being less than 90°.

[0060] The 24 bridges are spaced apart from each other in the circumferential direction.

[0061] The fan shroud 9 itself, in particular the grille of the fan shroud 9, is designed to be stiffer than the torque support 1.

[0062] The radial spacing area covered by the webs 24 is arranged between the radial spacing area covered by the inner ring 23 and the radial spacing area covered by the tab areas 22.

[0063] The circumferential angle region covered by the first tab region 22 is more than 60° apart in magnitude from the circumferential angle region covered by the first connection region. The circumferential angle region covered by the second tab region 22 is more than 60° apart in magnitude from the circumferential angle region covered by the first connection region.

[0064] This allows for an optimized shaping of the meander, i.e., as many meander loops as possible within a small radial spacing range.

[0065] Accordingly, the angle between the connecting line connecting the centers of gravity of the two tab areas 22 and the connecting line connecting the centers of gravity of the two connecting areas is greater than 60°, in particular 90°.

[0066] Preferably, if the two connecting lines are perpendicular to each other, highly accurate angle measurement by the angle sensor is possible, since the torsional stiffness exhibits the same values ​​in both the circumferential and counter-circumferential directions, meaning there is no preferred direction. This also applies in the presence of axial and radial tolerance deviations.

[0067] The torque support 1, i.e. a torque support part, is designed as a stamped part in one piece and as a single unit.

[0068] As from Figure 4 and Figure 5As can be seen, nuts 40 are welded to the side of the torque support 1 facing the fan shroud 9. Thus, the nuts 40 are bonded to the torque support 1 by a material connection. Screws 42 protruding through recesses 41 in the fan shroud are screwed into the nuts 40. The head of each screw 42 presses the fan shroud 9 onto the respective nut 40, thus positively connecting the torque support to the fan shroud 9 by means of the screws 42.

[0069] The housing part 2 of the angle sensor is positively connected in the circumferential direction by means of pins 43 passing through the torque support 1, i.e., rotationally fixed. Preferably, the pins 43 are force-fitted into bores in the housing 2.

[0070] Since the fan cover 9 is also positively connected to the housing part 7, in particular the stator housing, by means of screws, the torque is derived from the housing 2 of the angle sensor via the torque support 1 and via the fan cover 9 to the housing part 7.

[0071] The torque support 1 is therefore located on the inside of the fan cover 9 and is thus protected by the fan cover 9 against influences from the external environment. Reference symbol list

[0072] 1 Torque support 2 Housing, in particular stator, of the angle sensor 3 Shaft, in particular rotor shaft, of the angle sensor 4 Active part 5 Rotor shaft 6 Stator winding 7 Housing part 8 Fan 9 Fan cover 10 Fastening means, in particular screw with nut 11 Bearing flange 22 Tab area 23 Inner ring 24 Meandering web 25 Recess 26 Recess 40 Nut 41 Recess 42 Screw 43 Pin

Claims

1. Electric motor having a fan guard (9) and a rotor shaft (5) mounted rotatably relative to the fan guard (9) and an angle sensor, wherein a housing (2) of the angle sensor is connected to a torque support (1), which is connected to the fan guard (9), characterized in that the housing (2) is connected to an inner ring (23) of the torque support (1) by means of a first and a second connecting region of the torque support (1), wherein the torque support (1) comprises tab regions (22), which in particular project radially outwards and to which the fan guard (9) is connected, wherein a respective tab region (22) is connected to the inner ring (23) by means of webs of the torque support (1), wherein the webs (24) are spaced apart from each other in the circumferential direction, wherein the webs (24) are shaped in a meandering and / or meander-like manner such that the webs (24) have a circumferential angle that increases and then decreases multiple times as the radial distance from the axis of rotation of the rotor shaft (5) increases, wherein each of the webs (24) has regions that are radially spaced apart from each other in a respective circumferential angle range covered by said web.

2. Electric motor according to claim 1, characterized in that the respective tab region (22) is pressed against the fan guard (9) by means of a respective fastener, in particular a screw.

3. Electric motor according to any one of the preceding claims, characterized in that the inner ring (23) and / or the connecting regions are pressed against the housing (2) of the angle sensor by a screw.

4. Electric motor according to any one of the preceding claims, characterized in that the tab regions (22) are radially spaced apart from the inner ring (23) and from the connecting regions, the radial direction being relative to the axis of rotation of the rotor shaft (5).

5. Electric motor according to any one of the preceding claims, characterized in that the respective connecting region is spaced apart from the respective tab region (22) in the circumferential direction.

6. Electric motor according to any one of the preceding claims, characterized in that the radial distance range covered by the web, relative to the axis of rotation of the shaft (3), is arranged between the radial distance range covered by the tab regions (22) and the radial distance range covered by the connecting regions, or overlaps with these.

7. Electric motor according to any one of the preceding claims, characterized in that the rotor shaft (5) is rotatably mounted by means of a bearing accommodated in a bearing flange (11) of the electric motor, wherein the fan guard (9) is connected to the bearing flange (11), in particular is fastened to the bearing flange (11).

8. Electric motor according to any one of the preceding claims, characterized in that the angle sensor comprises a shaft (3) which is rotatable relative to the housing (2) of the angle sensor and which is co-rotatably connected to the rotor shaft (5).

9. Electric motor according to any one of the preceding claims, characterized in that the torque support (1) is embodied as a flat stamped sheet-metal part, wherein the normal to the plane containing the stamped sheet-metal part is oriented parallel to the axis of rotation of the rotor shaft.

10. Electric motor according to any one of the preceding claims, characterized in that the tab regions (22) bear in a parallel manner against the fan grille of the fan guard (9).

11. Electric motor according to any one of the preceding claims, characterized in that the housing (2) of the angle sensor is arranged on the side of the fan guard (9) remote from the bearing flange (11).