Electric motor with rotor

Abstract

The invention relates to an electric motor with a rotor, in particular a rotatably mounted rotor. The rotor has a rotor shaft which protrudes through a recess of a laminated core, wherein the laminated core has a hollow design, and the recess of the laminated core has a non-round design. The rotor shaft has a circular cylindrical lateral surface in the region covered by the laminated core in the axial direction, and a radially protruding shaft collar is molded onto the rotor shaft. The laminated core is positioned against the shaft collar, and an annular cavity is arranged in the shaft collar, in particular the annular cavity is introduced into the shaft collar, wherein a radial bore which passes through the shaft collar opens into the cavity, adhesive is arranged between the laminated core and the rotor shaft, and the annular cavity is at least partly filled wth adhesive.

Description

[0001] Electric motor with rotor

[0002] Description:

[0003] The invention relates to an electric motor with a rotor.

[0004] It is generally known that an electric motor has a rotatably mounted rotor.

[0005] From DE 10 2020 004 644 A1, the closest prior art is an electric motor with an active part attached to a shaft.

[0006] An electric motor with a rotor is known from DE 10 2021 003 896 A1.

[0007] An arrangement with a shaft-hub connection is known from DE 10 2011 113 876 B4.

[0008] A press connection of a rotor shaft is known from DE JP 2000 - 232 744 A.

[0009] From DE 10 2019 005 666 B3 an electric motor with an active part attached to a shaft is known.

[0010] A rotor for an electrical machine is known from DE 10 2017 214 309 A1.

[0011] A rotor for a permanent magnet dynamoelectric machine is known from DE 10 2008 027 758 A1.

[0012] The invention is therefore based on the object of developing an electric motor which is to enable simple production.

[0013] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.Important features of the invention in the electric motor with a rotor, in particular with a rotatably mounted rotor, are that the rotor has a rotor shaft which projects through a recess in the laminated core, wherein the laminated core is hollow, wherein the recess in the laminated core is non-circular and wherein the rotor shaft has a circular cylindrical outer surface in the area covered by the laminated core in the axial direction, wherein a radially projecting shaft collar is formed on the rotor shaft, wherein the laminated core is positioned against the shaft collar, wherein an annular cavity is arranged, in particular machined, in the shaft collar, wherein a radial bore passing through the shaft collar opens into the cavity, wherein adhesive is arranged between the laminated core and the rotor shaft and the annular cavity is at least partially filled with adhesive.

[0014] The advantage here is that during production, the laminated core can be pushed toward the shaft collar, and adhesive can be fed through the radial bore into the annular cavity, from which the free spaces, particularly the channels between the laminated core and the shaft, can be filled. The non-circular design of the radial inner surface of the laminated core creates free spaces when the laminated core is placed onto the cylindrical shaft, into which the adhesive can be fed, thus creating a bonded connection between the shaft and the laminated core.

[0015] In an advantageous embodiment, the laminated core comprises a stack of individual laminations, in particular wherein the stack of individual laminations is punched together, in particular wherein the stacking direction is aligned parallel to the axial direction, in particular parallel to the direction of the rotational axis of the rotor shaft. This is advantageous in that the laminated core is easy to manufacture as a stack. Alternatively, the stack is bonded together, in particular by means of adhesive and / or bonding varnish.

[0016] In an advantageous embodiment, axially extending, particularly continuous, channels are formed between the rotor shaft and the laminated core, which open into the annular cavity. The advantage here is that the channels can be formed simply by making the individual laminations non-circular, thus achieving a materially bonded connection.

[0017] In an advantageous embodiment, a further radially directed bore, in particular a radial bore, extending through the shaft collar opens into the cavity, in particular wherein the further bore is arranged 180° circumferentially from the radial bore, in particular wherein the further bore covers the same radial distance range as the radial bore. The advantage here is that imbalance can be reduced, in particular if the radial bore removes the same amount of material from the shaft collar as the further bore. Furthermore, a more uniform filling of the channels with adhesive is possible.

[0018] In an advantageous embodiment, the area covered by the shaft collar in the axial direction encompasses the area covered by the annular cavity in the axial direction. The advantage here is that the cavity can be manufactured as a recess. This enables simple production by grooving with a turning tool.

[0019] In an advantageous embodiment, permanent magnets are arranged and / or attached to the radial outer circumference of the laminated core. The advantage here is that the motor can be designed as a synchronous motor.

[0020] In an advantageous embodiment, the laminated core is pushed and / or clipped onto the rotor shaft. This allows for simple manufacturing by sliding and / or clipping. In an advantageous embodiment, the channels are spaced apart from one another in the circumferential direction, in particular evenly spaced. This is advantageous because the connecting force is evenly distributed.

[0021] In an advantageous embodiment, the radially inner boundary of the cavity, in particular the smallest radial distance of the cavity, has a monotonically, in particular strictly monotonically, decreasing radial distance value with increasing distance from the laminated core in the axial direction. It is advantageous that the groove is made at an angle, in particular not in a purely axial or purely radial direction. Thus, with increasing depth of the groove, the radial distance to the rotatably mounted shaft becomes increasingly smaller and the distance to the laminated core increasingly larger.

[0022] In an advantageous embodiment, the radially outer boundary of the cavity, in particular the largest radial distance of the cavity, has a monotonically, in particular strictly monotonically, decreasing radial distance value with increasing distance from the laminated core in the axial direction. It is advantageous that the annular cavity has an axial region in which, with increasing distance from the laminated core, the largest radial distance of the cavity relative to the rotational axis of the rotor shaft becomes increasingly smaller, i.e., decreases monotonically, in particular strictly monotonically.

[0023] In an advantageous embodiment, at least in one axial sub-region, the distance between the largest and smallest radial distance of the cavity is independent of the axial position, in particular, it is constant. It is advantageous that the annular width of the annular cavity, measured perpendicular to the outer contour of the annular cavity, is constant.

[0024] In an advantageous embodiment, the annular cavity is formed completely and / or continuously circumferentially. This is advantageous in that the adhesive can be provided at all circumferential angular positions for channels and gaps arranged between the rotor shaft and the laminated core, since the cavity is present at every circumferential position, allowing adhesive to escape from it to the laminated core.

[0025] In an advantageous embodiment, the ring axis of the annular cavity is aligned coaxially with the rotational axis of the rotor shaft. This allows for even adhesive distribution in the circumferential direction. In an advantageous embodiment, the laminated core contacts the shaft collar. This is advantageous because the shaft collar serves as an axial stop and thus also contributes to the axial positioning of the laminated core.

[0026] In an alternative advantageous embodiment, a seal is arranged between the laminated core and the shaft collar, which seal is located radially outside the channels, the annular cavity, and / or the recess. This is advantageous in that the adhesive penetrates from the cavity into the channels between the laminated core and the rotor shaft, but does not leak into the external environment.

[0027] In an advantageous embodiment, the annular cavity has a trapezoidal cross-section, in particular a rectangular trapezoidal cross-section. Advantageously, the radially outer and radially inner boundaries extend at a constant distance from one another, thus allowing for simple production by means of a groove with a tool, in particular a turning tool.

[0028] In an advantageous embodiment, the radial clearance area covered by the shaft collar is encompassed by the radial clearance area covered by the laminated core. Advantageously, the cavity and its opening facing the laminated core are arranged within the radial clearance area of ​​the laminated core. This prevents the adhesive from leaking into the external environment, particularly the radially outer environment.

[0029] In an advantageous embodiment, the individual sheets of the laminated core are shaped such that the mouth opening of the channel closest to the respective radial bore or hole in the circumferential direction and / or counter to the circumferential direction has a smaller cross-sectional area than the mouth opening of a channel arranged further away in the circumferential direction or counter to the circumferential direction, wherein the cross-sectional area of ​​the channel closest to the respective radial bore or hole in the circumferential direction and / or counter to the circumferential direction increases monotonically, in particular strictly monotonically, in the axial direction with increasing distance from the shaft collar. The advantage here is that the manufacture of the laminated core is simple. This is because only the first individual sheet needs to have correspondingly smaller recesses, which can be easily implemented in the punching machine using a controllable tool.The first individual sheet, in particular, has the narrowed openings facing the cavity. The other individual sheets provide the larger channel cross-section. This ensures even distribution of the adhesive around the circumference.

[0030] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0031] The invention will now be explained in more detail using schematic illustrations:

[0032] Figure 1 shows an exploded oblique view of the rotor of an electric motor according to the invention.

[0033] Figure 2 shows a rotor shaft 1 of the rotor in side view.

[0034] Figure 3 shows a longitudinal section through the rotor.

[0035] Figure 4 shows an enlarged section of Figure 3.

[0036] As shown in the figures, the rotor of the electric motor has a rotor shaft 1 onto which a laminated core 2 is placed.

[0037] The laminated core 1 is preferably manufactured as a punched-packed stack of individual sheets.

[0038] The rotor shaft 1 is inserted into the laminated core with play, whereby a material connection between the shaft 1 and the laminated core 2 is provided, in particular by interposing an adhesive.

[0039] For this purpose, the inner circumference of the laminated core 2 is not designed as the outer surface of a circular cylinder, but rather has radially directed elevations that are spaced apart from one another in the circumferential direction, in particular, are regularly spaced from one another. Thus, the smallest radial spacing of the laminated core depends on the circumferential angle, in particular, it is a non-vanishing periodic function of the circumferential angle.

[0040] However, since the laminated core is placed on a section of the rotor shaft 1 which resembles the outer surface of a circular cylinder, axially extending channels are formed between the laminated core 2 and the rotor shaft 1, into which the adhesive can be introduced, which creates a material connection between the laminated core 2 and the rotor shaft 1.

[0041] To apply the adhesive, a radially protruding shaft collar 4 is formed on the shaft 1, particularly in the circumferential direction, which is continuously radially encircling. The axial direction is parallel to the direction of the shaft's rotational axis. The radial and circumferential directions are also related to this rotational axis.

[0042] Shaft collar 4 acts, on the one hand, as an axial stop for a bearing whose inner ring is mounted on the shaft. Thus, the bearing, especially the inner ring of the bearing, is limited in the axial direction.

[0043] In addition, the shaft collar also acts as a stop for the laminated core 2, which is arranged on the side of the shaft collar 4 facing away from the bearing.

[0044] Furthermore, a radial bore 3 is provided in the shaft collar 4, particularly on the outer circumference of the shaft collar 4, which leads to a lubricant reservoir located in a tube-like cavity. This cavity is bounded by the shaft collar 4 of the rotor shaft 1 and by the laminated core 2.

[0045] The cavity is produced by turning with a cutting tool, in particular a turning tool, which is cut into the material of the shaft collar 4 at an angle between 20° and 45°, in particular at an angle of 30°, to the axis of rotation of the rotor shaft 1.

[0046] The cavity is continuous in the circumferential direction. Radial bore 3 opens into the cavity.

[0047] Likewise, the channels created by the radial elevations open into the tube-like cavity.

[0048] During production, liquid adhesive can initially be fed through the radial bore 3 into the tubular cavity, from which the axially extending channels arranged between the laminated core 2 and the rotor shaft 1 are supplied with adhesive.

[0049] After the adhesive has cured, it remains in both the channels and the tubular cavity located in the shaft collar 4. This also fixes the axial positioning of the laminated core 2 on the rotor shaft 1, particularly relative to the shaft collar 4.

[0050] To produce the tube-like cavity, a recess is made, in particular with the above-mentioned tool, which extends so far into the shaft collar 4 that the radial bore 3 opens into the tube-like cavity.

[0051] The tube-like cavity has the shape of a ring whose ring axis is aligned coaxially with the axis of rotation of the shaft.

[0052] Thus, the area covered by the puncture and / or the tube-like cavity in the axial direction overlaps or encompasses the area covered by the radial bore 3 in the axial direction.

[0053] The radial distance area covered by the hose-like cavity overlaps with the radial distance area covered by the radial bore, in particular wherein the radial distance is related to the axis of rotation of the shaft.

[0054] The inner ring of the bearing is mounted on the rotor shaft 1. In particular, the bearing, in particular the inner ring, is arranged on the side of the shaft collar opposite the laminated core 2.

[0055] The cross-section, in particular a ring cross-section, of the tubular cavity is rectangular, in particular with one side of the rectangle forming an angle between 20° and 45°, in particular an angle of 30°, to the rotational axis of the rotor shaft 1. The rectangular cross-section opens into the area surrounding the rotor shaft 1, i.e., toward the laminated core, on the side axially remote from the bearing. The opening of the tubular cavity is thus covered by the laminated core 2 or merges into the channels formed between the laminated core 2 and the rotor shaft 1.

[0056] An undercut is formed by means of the tubular cavity.

[0057] The depth of the cut into the material of the shaft collar 4 is such that the volume of the tubular cavity has a predetermined value. The cross-sectional plane of the tubular cavity contains the rotational axis of the rotor shaft 1.

[0058] An indexable insert can be used as a turning tool. In particular, the tubular and / or annular cavity can be created using axial grooving with this indexable insert.

[0059] The adhesive is preferably light-activated. This eliminates the need for seals between the shaft collar and the laminated core.

[0060] In further embodiments according to the invention, a rounded elongated cross section is used instead of the rectangular cross section.

[0061] In further embodiments according to the invention, an adhesive connection and / or a connection with baking varnish is carried out instead of the punched packaging of the stack.

[0062] In further embodiments according to the invention, instead of inserting the rotor shaft into the laminated core with play, the laminated core is pressed in with almost or completely zero play and is thus non-positively connected to the laminated core 2. The adhesive connection is then an additional connection, so that a high level of safety can be achieved.

[0063] In further embodiments according to the invention, a further radial bore is provided through the shaft collar 4 in order to compensate for the imbalance and to achieve a more uniform filling of the channels.

[0064] In further embodiments of the invention, those channels that are closest to the radial bore in the circumferential direction or counter to the circumferential direction are designed with an opening that narrows toward the cavity, in that at least the individual sheet closest to the shaft collar 4, i.e., the first individual sheet of the sheet stack, has correspondingly reduced openings for the respective channel. This evens out the distribution of the adhesive, which is fed into the cavity at high pressure via the radial bore.

[0065] 1 rotor shaft 2 laminated core

[0066] 3 Radial bore

[0067] 4 wave collar

[0068] 5 Inner circumference of the laminated core 2

[0069] 20 puncture

Claims

Patent claims:

1. Electric motor with a rotor, in particular with a rotatably mounted rotor, the rotor having a rotor shaft which projects through a recess in a laminated core, the laminated core being hollow, the recess in the laminated core being non-circular, and the rotor shaft having a circular-cylindrical outer surface in the region covered by the laminated core in the axial direction, characterized in that a radially projecting shaft collar is formed on the rotor shaft, the laminated core being positioned against the shaft collar, an annular cavity being arranged, in particular machined, in the shaft collar, a radial bore passing through the shaft collar opening into the cavity, adhesive being arranged between the laminated core and the rotor shaft, and the annular cavity being at least partially filled with adhesive.

2. Electric motor according to claim 1, characterized in that the laminated core comprises a stack of individual laminated sheets, in particular wherein the stack of individual laminated sheets is punched together, in particular wherein the stacking direction is aligned parallel to the axial direction, in particular thus parallel to the direction of the axis of rotation of the rotor shaft.

3. Electric motor according to one of the preceding claims, characterized in that a further, radially directed bore, in particular a radial bore, passing through the shaft collar opens into the cavity, in particular wherein the further bore is arranged 180° away from the radial bore in the circumferential direction, in particular and the further bore covers the same radial distance range as the radial bore.

4. Electric motor according to one of the preceding claims, characterized in that axially extending, in particular continuous, channels are formed between the rotor shaft and the laminated core, which open into the annular cavity.

5. Electric motor according to one of the preceding claims, characterized in that the area covered by the shaft collar in the axial direction comprises the area covered by the annular cavity in the axial direction.

6. Electric motor according to one of the preceding claims, characterized in that permanent magnets are arranged and / or fastened on the radial outer circumference of the laminated core, and / or that the laminated core is pushed and / or plugged onto the rotor shaft.

7. Electric motor according to one of the preceding claims, characterized in that the channels are spaced apart from one another in the circumferential direction, in particular evenly spaced.

8. Electric motor according to one of the preceding claims, characterized in that the radially inner boundary of the cavity, in particular the smallest radial distance of the cavity, has a monotonically, in particular strictly monotonically, decreasing radial distance value with increasing distance to the laminated core in the axial direction.

9. Electric motor according to one of the preceding claims, characterized in that the radially outer boundary of the cavity, in particular the largest radial distance of the cavity, has a monotonically, in particular strictly monotonically, decreasing radial distance value with increasing distance from the laminated core in the axial direction.

10. Electric motor according to one of the preceding claims, characterized in that at least in an axial partial region the distance between the largest and the smallest radial distance of the cavity is independent of the axial position, in particular is constant.

11. Electric motor according to one of the preceding claims, characterized in that the annular cavity is formed completely and / or continuously circumferentially.

12. Electric motor according to one of the preceding claims, characterized in that the ring axis of the annular cavity is aligned coaxially with the axis of rotation of the rotor shaft.

13. Electric motor according to one of the preceding claims, characterized in that the laminated core contacts the shaft collar or that a seal is arranged between the laminated core and the shaft collar, which seal is arranged radially outside the channels, the annular cavity and / or the recess.

14. Electric motor according to one of the preceding claims, characterized in that the annular cavity has a trapezoidal cross-section, in particular a rectangular trapezoidal cross-section and / or that the radial spacing region covered by the shaft collar is encompassed by the radial spacing region covered by the sheet metal pact.

15. Electric motor according to one of the preceding claims, characterized in that in particular the individual sheets of the laminated core are shaped such that the mouth opening of the channel which is closest to the respective radial bore or bore in the circumferential direction and / or counter to the circumferential direction has a smaller cross-sectional area than the mouth opening of a channel which is arranged further away in the circumferential direction or counter to the circumferential direction, wherein the cross-sectional area of ​​the channel which is closest to the respective radial bore or bore in the circumferential direction and / or counter to the circumferential direction increases monotonically, in particular strictly monotonically, in the axial direction with increasing distance from the shaft collar.

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