Electric machine with rotor

Abstract

The invention relates to an electric machine having a rotor, in particular a rotatably mounted rotor, the rotor having a rotor shaft which passes through a recess of a laminated core, the laminated core being hollow, the recess of the laminated core being non-circular, and the rotor shaft being rotatably mounted on the rotor shaft. The rotor shaft has a cylindrical outer circumferential surface in the region covered by the laminated core in the axial direction, a radially projecting shaft shoulder is formed on the rotor shaft, the laminated core abuts against the shaft shoulder, an annular cavity is arranged, in particular machined, in the shaft shoulder, a radial bore through the shaft shoulder opens into the cavity, and the radial bore is in the axial direction of the rotor shaft. An adhesive material is arranged between the laminated core and the rotor shaft, and the annular cavity is at least partially filled with the adhesive material.

Description

Technical Field

[0001] The invention relates to an electric machine having a rotor. Background Art

[0002] As is known, electric machines have a rotatably supported rotor.

[0003] As the closest prior art, an electric machine having an active component which is mounted on a shaft is known from DE 10 2020 004 644 A1.

[0004] An electric machine having a rotor is known from DE 10 2021 003 896 A1.

[0005] A device having a shaft-hub connection is known from DE 10 2011 113 876 B4.

[0006] A crimp connection of a rotor shaft is known from DE JP 2000-232 744 A.

[0007] DE 10 2019 005 666 B3 discloses an electric machine having an active component which is mounted on a shaft.

[0008] A rotor for an electric machine is known from DE 10 2017 214 309 A1.

[0009] A rotor for a permanently excited electric machine is known from DE 10 2008 027 758 A1. Summary of the invention

[0010] The object of the present invention is therefore to improve an electric machine, wherein simple production is to be achieved.

[0011] This object is achieved according to the invention by an electric machine according to the features specified in claim 1 .

[0012] In an electric machine with a rotor, in particular with a rotatably mounted rotor, an essential feature of the invention is that the rotor has a rotor shaft which passes through a recess in the laminated core.

[0013] Among them, the lamination stack is hollow.

[0014] The notch of the lamination stack is non-circular.

[0015] The rotor shaft has a cylindrical outer circumferential surface in the region covered by the lamination stack in the axial direction.

[0016] A radially protruding shoulder is formed on the rotor shaft.

[0017] The lamination stack rests against the shaft shoulder.

[0018] In this case, an annular cavity is arranged, in particular machined, in the shaft shoulder.

[0019] In this case, a radial hole through the shaft shoulder opens into the cavity.

[0020] In this case, an adhesive is arranged between the laminated core and the rotor shaft, and the annular cavity is at least partially filled with the adhesive.

[0021] The advantage here is that during production the lamination stack can be pushed onto the shaft shoulder and adhesive can be supplied through the radial bore to the annular cavity from which a gap, in particular a channel, between the lamination stack and the shaft can be filled. Since the non-circular design of the radial inner side of the lamination stack creates a gap when the lamination stack is placed onto the cylindrical shaft, adhesive can be supplied into this gap and thus create a material-locking connection between the shaft and the lamination stack.

[0022] In an advantageous embodiment, the laminated core has a stack of individual laminations, in particular wherein the stack of individual laminations is stamped and encapsulated, in particular wherein the stacking direction is parallel to the axial direction, in particular parallel to the direction of the axis of rotation of the rotor shaft. This has the advantage that the laminated core can be easily manufactured as a stack. Alternatively, the stack is connected in a material-locking manner, in particular by means of an adhesive and / or an adhesive varnish.

[0023] In an advantageous embodiment, a channel extending in the axial direction, in particular a continuous channel, is formed between the rotor shaft and the lamination stack, the channel opening into the annular cavity. The advantage here is that the channel can be formed by a purely non-circular embodiment of a single lamination and thus a material-locked connection can be formed.

[0024] In an advantageous embodiment, a further bore, in particular a further radial bore, which is directed radially through the shaft shoulder, opens into the cavity.

[0025] In particular, the further hole is arranged 180° apart from the radial hole in the circumferential direction, and in particular the further hole covers the same radial extent as the radial hole. This has the advantage that the imbalance can be reduced, in particular when the radial hole removes the same mass of material from the shoulder as the further hole. In addition, the channel can be filled with adhesive material more evenly.

[0026] In an advantageous design, the area covered by the shoulder in the axial direction includes an area covered by the annular cavity in the axial direction. The advantage here is that the cavity can be manufactured as a groove. Therefore, simple manufacturing can be achieved by inserting a turning tool.

[0027] In an advantageous embodiment, permanent magnets are arranged and / or fixed on the radial outer circumference of the laminated core. This has the advantage that the electric machine can be designed as a synchronous machine.

[0028] In an advantageous design, the lamination stack is pushed onto and / or sleeved onto the rotor shaft. Advantageously, simple manufacturing can be achieved by pushing onto and / or sleeved onto the rotor shaft.

[0029] In an advantageous embodiment, the channels are spaced apart from one another in the circumferential direction, in particular spaced apart uniformly. This has the advantage that the connecting forces are evenly distributed.

[0030] In an advantageous embodiment, the radial inner boundary of the cavity, in particular the minimum radial distance of the cavity (ring inner diameter), has a monotonically, in particular strictly monotonically decreasing radial distance value as the distance from the laminated core increases in the axial direction. It is advantageous here that the groove is realized obliquely, that is, in particular not purely in the axial direction or purely in the radial direction. Thus, as the depth of the groove increases, the radial distance from the rotatably mounted shaft also decreases, and the distance from the laminated core also increases.

[0031] In an advantageous embodiment, the radially outer boundary of the cavity, in particular the maximum radial distance of the cavity (ring outer diameter), 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 here that the annular cavity has an axial region in which the maximum radial distance of the cavity relative to the axis of rotation of the rotor shaft decreases with increasing distance from the laminated core, i.e. decreases monotonically, in particular strictly monotonically.

[0032] In an advantageous embodiment, at least in the axial sub-region, the distance between the maximum radial distance and the minimum radial distance of the cavity is independent of the axial position, ie in particular constant. The advantage here is that the ring width of the annular cavity measured perpendicular to the outer contour of the annular cavity is constant.

[0033] In an advantageous embodiment, the annular cavity is designed to be completely and / or uninterruptedly circumferentially surrounding. This has the advantage that the channels and the gaps arranged between the rotor shaft and the laminated core can be provided with adhesive material at all circumferential angular positions, since the cavity is present at every circumferential position and the adhesive material can thus flow out of it into the laminated core.

[0034] In an advantageous embodiment, the ring axis of the annular cavity is coaxial with the rotation axis of the rotor shaft. This has the advantage that a uniform distribution of the adhesive in the circumferential direction can be achieved.

[0035] In an advantageous embodiment, the core stack contacts the shaft shoulder. The advantage here is that the shaft shoulder serves as an axial stop and thus also contributes to the axial positioning of the core stack.

[0036] In an alternative advantageous design, a seal is arranged between the lamination stack and the shaft shoulder, the seal being arranged radially outside the channel, the annular cavity and / or the groove. The advantage here is that although the adhesive material enters from the cavity into the channel between the lamination stack and the rotor shaft, it does not escape into the external environment.

[0037] In an advantageous embodiment, the annular cavity has a trapezoidal cross section, in particular a right-angled trapezoidal cross section. The advantage here is that the radially outer and radially inner boundaries extend at a constant distance from one another and thus can be manufactured simply by making the grooves with a tool, in particular a turning tool.

[0038] In an advantageous design, the radial range covered by the lamination stack includes the radial range covered by the shaft shoulder. The advantage here is that the cavity and its opening toward the lamination stack are arranged within the radial range of the lamination stack. Thus, the adhesive material is prevented from overflowing into the external environment, in particular the radial external environment.

[0039] In an advantageous embodiment, the individual laminations of the lamination stack are formed in such a way that the cross-section of the openings of the channels which are respectively closest to the corresponding radial bore or bore in the circumferential direction and / or counter to the circumferential direction is smaller than the cross-section of the openings of the channels which are arranged further away in the circumferential direction or counter to the circumferential direction.

[0040] In this case, the cross section of the channel closest to the corresponding radial hole or hole in the circumferential direction and / or opposite to the circumferential direction increases monotonically, in particular strictly monotonically, in the axial direction as the distance from the shaft shoulder increases. The advantage here is that the manufacture of the lamination stack can be easily realized. Because the lamination stack only needs to have a correspondingly smaller notch in the first single lamination, but this is easily realized in a punch press by a controllable tool. The first single lamination, in particular, or a plurality of first single laminations, includes a narrowed orifice facing the cavity. Other single laminations provide a larger channel cross section. Therefore, the distribution of the adhesive material on the periphery is uniform.

[0041] Further advantages are given by the dependent claims. The invention is not limited to the feature combinations of the claims. For a person skilled in the art, in particular from the objectives proposed and / or by comparison with the prior art, other reasonable combinations of the claims and / or the features of the individual claims and / or the features of the description and / or the features of the drawings are available. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Now the present invention is described in detail according to the schematic diagram:

[0043] exist Figure 1 The rotor of the electric machine according to the invention is shown in an exploded oblique view.

[0044] exist Figure 2 The rotor shaft 1 of the rotor is shown in a side view.

[0045] exist Figure 3 A longitudinal section of the rotor is shown in FIG.

[0046] exist Figure 4 The enlarged Figure 3 Part of. DETAILED DESCRIPTION

[0047] As shown in the figure, the rotor of the electric machine has a rotor shaft 1 , onto which a laminated core 2 is placed.

[0048] The laminated core 1 is preferably produced as a punched-packed stack of individual laminates.

[0049] The rotor shaft 1 is inserted into the laminated core with play, wherein a material-locking connection is provided between the shaft 1 and the laminated core 2 , in particular by means of an intermediately arranged adhesive material.

[0050] For this purpose, the inner circumference of the lamination stack 2 is not designed as the outer circumference of a cylinder, but has radially directed protrusions, which are spaced apart from each other in the circumferential direction, especially regularly spaced apart from each other. Therefore, the minimum radial distance of the lamination stack is related to the circumferential angle, especially as a non-zero periodic function of the circumferential angle.

[0051] However, the lamination stack is inserted onto the same section of the rotor shaft 1 as the outer circumference of the cylinder, forming a channel extending axially between the lamination stack 2 and the rotor shaft 1, into which an adhesive material can be introduced, which produces a material-locked connection between the lamination stack 2 and the rotor shaft 1.

[0052] For the introduction of the adhesive, a radially protruding shoulder 4 is formed on the shaft 1 and in particular circumferentially extends radially without interruption in the circumferential direction.

[0053] The axial direction is parallel to the direction of the axis of rotation of the shaft. The radial direction and the circumferential direction are also based on the axis of rotation.

[0054] The shaft shoulder 4 acts as an axial stop of the bearing on the one hand, and the inner ring of the bearing is mounted on the shaft. Therefore, the bearing, in particular the inner ring of the bearing, is limited in the axial direction.

[0055] Furthermore, the shoulder also serves as a stop for the laminated core 2 which is arranged on the side of the shoulder 4 facing away from the bearing.

[0056] Furthermore, radial holes 3 are formed in the shoulder 4 , in particular on the outer circumference of the shoulder 4 , which lead to a lubricant reservoir formed in a tubular cavity. The cavity is delimited by the shoulder 4 of the rotor shaft 1 and by the laminated core 2 .

[0057] The cavity is produced by turning with a cutting tool, in particular a turning tool, which cuts into the material of the shoulder 4 at an angle of between 20° and 45°, in particular at an angle of 30°, to the axis of rotation of the rotor shaft 1 .

[0058] The cavity is designed to be uninterrupted in the circumferential direction. The radial holes 3 open into the cavity.

[0059] The channel produced by the radial projection likewise opens into the tubular cavity.

[0060] During production, liquid adhesive can therefore first be supplied through the radial bores 3 to the tubular cavity, from which the axially extending channels arranged between the laminated core 2 and the rotor shaft 1 are supplied with adhesive.

[0061] After the adhesive has cured, it remains in the channel and in the tubular cavity arranged in the shaft shoulder 4. In this way, the axial position of the laminated core 2 on the rotor shaft 1, in particular relative to the shaft shoulder 4, is also fixed.

[0062] In order to produce the tubular cavity, a groove is produced, in particular with the aforementioned tool, which groove extends so far into the shaft shoulder 4 that the radial bore 3 opens into the tubular cavity.

[0063] The tubular cavity has the shape of a ring, the ring axis of which is coaxial with the axis of rotation of the shaft.

[0064] Therefore, the area covered by the groove and / or the tubular cavity in the axial direction overlaps with or includes the area covered by the radial hole 3 in the axial direction.

[0065] The radial area covered by the tubular cavity overlaps the radial area covered by the radial opening, in particular wherein the radial distance is based on the axis of rotation of the shaft.

[0066] The inner ring of the bearing is placed onto the rotor shaft 1. In particular, the bearing, in particular the inner ring, is arranged on the side of the shaft shoulder facing away from the laminated core 2.

[0067] The cross section, in particular the annular cross section, of the tubular cavity is rectangular, in particular wherein one side of the rectangle forms an angle of between 20° and 45°, in particular 30°, with respect to the axis of rotation of the rotor shaft 1. The rectangular cross section opens into the surroundings of the rotor shaft 1, i.e. into the lamination stack, on the side facing away from the bearing in the axial direction. The opening of the tubular cavity is thus covered by the lamination stack 2 or transitions into a channel formed between the lamination stack 2 and the rotor shaft 1.

[0068] The undercut is formed by means of the tubular cavity.

[0069] The depth of the recess in the material of the shoulder 4 is formed such that the volume of the tubular cavity has a predetermined value.

[0070] The section plane of the cross section of the tubular cavity contains the axis of rotation of the rotor shaft 1 .

[0071] The indexable insert can be used as a turning tool. In particular, the tubular and / or annular cavity can be produced by axial turning using such an indexable insert.

[0072] Preferably, the adhesive material is designed to be light-stimulable. In this way, a seal between the shaft shoulder and the lamination stack can be omitted.

[0073] In a further embodiment according to the invention, a rounded elongated cross section is used instead of a rectangular cross section.

[0074] In further exemplary embodiments according to the invention, instead of stacking the punched packaging, an adhesive connection and / or a connection with an adhesive varnish is carried out.

[0075] In a further embodiment 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 connected in a force-fitting manner to the laminated core 2. The adhesive connection is an additional connection, which allows a high degree of safety.

[0076] In a further embodiment according to the invention, a further radial bore is provided through the shaft shoulder 4 in order to compensate for the imbalance and achieve a more uniform filling of the channel.

[0077] In a further embodiment according to the invention, the channel closest to the radial bore in the circumferential direction or counter to the circumferential direction is designed with an opening that tapers toward the cavity, wherein at least the individual lamination of the lamination stack closest to the shoulder 4, i.e. the first individual lamination, has a correspondingly smaller opening for the respective channel. The distribution of the adhesive material introduced into the cavity under high pressure through the radial bore is thus homogenized.

[0078] List of reference numerals:

[0079] 1 Rotor shaft

[0080] 2 lamination pack

[0081] 3 Radial holes

[0082] 4 Shoulder

[0083] 5 Inner circumference of lamination pack 2

[0084] 20 grooves

Claims

1. An electric machine having a rotor, in particular a rotatably supported rotor, The rotor has a rotor shaft, which passes through the notch of the lamination stack. The lamination stack is hollow. The notch of the lamination stack is non-circular. The rotor shaft has a cylindrical outer circumferential surface in the region covered by the lamination stack in the axial direction. It is characterized in that A radially protruding shoulder is formed on the rotor shaft. The lamination stack rests against the shaft shoulder. An annular cavity is arranged, in particular machined, in the shaft shoulder. A radial hole through the shoulder leads into the cavity. An adhesive is arranged between the laminated core and the rotor shaft, and the annular cavity is at least partially filled with the adhesive.

2. The motor according to claim 1, It is characterized in that The lamination pack has a stack of single laminations, In particular, stacks of single laminations are punched and packaged. In particular, the stacking direction is parallel to an axial direction, in particular to the direction of the axis of rotation of the rotor shaft.

3. An electric machine according to any one of the preceding claims, It is characterized in that A further bore, in particular a further radial bore, which is directed radially through the shaft shoulder and opens into the cavity, In particular, the further hole is arranged at a distance of 180° from the radial hole in the circumferential direction, and in particular, the further hole covers the same radial extent as the radial hole.

4. An electric machine according to any one of the preceding claims, It is characterized in that A channel extending in the axial direction, in particular a continuous channel, is formed between the rotor shaft and the laminated core and opens into the annular cavity.

5. An electric machine according to any one of the preceding claims, It is characterized in that The region covered by the shaft shoulder in the axial direction includes the region covered by the annular cavity in the axial direction.

6. An electric machine according to any one of the preceding claims, It is characterized in that A permanent magnet is arranged and / or fixed on the radial outer periphery of the lamination stack. and / or, The lamination stack is pushed onto and / or slid onto the rotor shaft.

7. An electric machine according to any one of the preceding claims, It is characterized in that The channels are spaced apart from one another in the circumferential direction, in particular spaced apart evenly.

8. An electric machine according to any one of the preceding claims, It is characterized in that The radial inner boundary of the cavity, in particular the minimum radial distance of the cavity, has a radial distance value which decreases monotonically, in particular strictly monotonically, with increasing distance from the laminated core in the axial direction.

9. An electric machine according to any one of the preceding claims, It is characterized in that The radially outer boundary of the cavity, in particular the maximum radial distance of the cavity, has a radial distance value which decreases monotonically, in particular strictly monotonically, with increasing distance from the laminated core in the axial direction.

10. An electric machine according to any one of the preceding claims, It is characterized in that At least in an axial sub-region, the distance between a maximum radial distance and a minimum radial distance of the cavities is independent of the axial position, ie, in particular, is constant.

11. An electric machine according to any one of the preceding claims, It is characterized in that The annular cavity is designed to extend completely and / or uninterruptedly around the circumferential direction.

12. An electric machine according to any one of the preceding claims, It is characterized in that The ring axis of the annular cavity is coaxial with the rotation axis of the rotor shaft.

13. An electric machine according to any one of the preceding claims, It is characterized in that The lamination stack contacts the shaft shoulder. or, A seal is arranged between the laminated core and the shaft shoulder, which seal is arranged radially outside the channel, the annular cavity and / or the groove.

14. An electric machine according to any one of the preceding claims, It is characterized in that The annular cavity has a trapezoidal cross section, in particular a right-angled trapezoidal cross section, and / or, The radial area covered by the lamination stack includes the radial area covered by the shaft shoulder.

15. An electric machine according to any one of the preceding claims, It is characterized in that In particular, the individual laminations of the lamination pack are formed in such a way that: the cross section of the opening of the channel which is closest to the corresponding radial hole or hole in the circumferential direction and / or counter to the circumferential direction is smaller than the cross section of the opening of the channel which is arranged farther away in the circumferential direction or counter to the circumferential direction, The cross section 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, with increasing distance from the shaft shoulder in the axial direction.

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