Electric machine with stator sleeve torsion resistance

Abstract

The invention relates to an electric machine comprising an assembly formed by a stator sleeve (17) and a stator plate pack (15), the stator sleeve (17) being inserted in a hollow cylindrical machine housing (1) in a rotationally fixed manner, characterized in that the stator sleeve (17) is extended in the axial direction by at least one fastening element (27), which protrudes in particular with an axial height (a) over an end-side stator sleeve edge (28), the fixing element (27) is connected to the housing-side counter contour (31) in a form-fitting manner in order to provide a torque resistance of the stator sleeve (17) relative to the motor housing (1).

Description

Technical Field

[0001] The invention relates to an electric motor. Background Art

[0002] In the electric machine, the stator can be mounted directly into a hollow cylindrical motor housing or, alternatively, a two-stage mounting process can be carried out, wherein in a first mounting step the stator lamination package is pressed into a stator sleeve and in a subsequent second mounting step the assembly consisting of the stator sleeve and the stator lamination package pressed therein is mounted into the motor housing.

[0003] In the above-mentioned type of motor, the assembly consisting of the stator sleeve and the stator lamellae is inserted into the hollow cylindrical motor housing in a torsion-proof manner. In order to position the assembly consisting of the stator sleeve and the stator lamellae in the motor housing in a torsion-proof manner, for example, the stator sleeve can be pressed into the motor housing for welding or optionally bolted connection. However, in the prior art, the torsion resistance achieved in this way brings about excessive structural space consumption. In addition, the following situation must be considered: the stator sleeve is deformed due to the pressing of the stator lamellae. Therefore, the torsion resistance between the stator sleeve and the motor housing must be designed with a complex structure so that the tolerance caused by the deformation of the stator sleeve can be compensated.

[0004] DE 10 202 0 114 748 A1 discloses an electric motor with a housing-side connection of a stator. In this case, the stator lamellae are fixed to the first bearing shield of the motor housing by several bolts relative to its axial side. DE 10 202 1 122 580 A1 discloses a method for manufacturing a rotor with an axially fixed design. FR 3 072 223 B1 discloses an electric motor. Its stator is arranged in a housing, which consists of two housing parts, which are clamped together by bolts. Summary of the invention

[0005] The object of the present invention is to provide an electric machine in which, compared with the prior art, the rotational fixation of the stator sleeve in the motor housing can be achieved in a structurally simple manner and with sufficiently large tolerance compensation.

[0006] This object is achieved by an electric machine according to the invention.

[0007] The invention relates to an electric motor with a cylindrical stator sleeve, into which a stator lamellae are pressed during the connection process. The assembly consisting of the stator sleeve and the stator lamellae is inserted into a hollow cylindrical motor housing in a torsion-proof manner. The torsion-proofness of the stator sleeve relative to the motor housing is provided as follows: Therefore, the stator sleeve is extended axially by at least one fixing element. The fixing element protrudes axially above the edge of the stator sleeve on the end side. In the assembled state, the fixing element is form-locked with a matching contour on the housing side. Therefore, the torsion-proofness according to the invention is arranged in axial alignment with the stator sleeve in a structurally simple manner and in a manner with reduced space consumption. In particular, no additional installation space is required on the radially outer side and / or radially inner side of the stator sleeve.

[0008] In one technical embodiment, the fixing element can be a component that is independent of the stator sleeve and can be connected to the stator sleeve. In this way, the stator sleeve can be provided to a large extent with a conventional sleeve geometry, which only requires additional connection points for the fixing element. In a specific embodiment variant, the fixing element can be a bolt. In the assembled state, the bolt is threadedly connected with its bolt shaft to the motor housing to ensure the torsion resistance.

[0009] For the purpose of torsion resistance and necessary tolerance compensation, the threaded connection is preferably designed such that the screw shank can pass through a cylindrical screw passage in the motor housing and its screw tip can engage with a nut thread outside the housing.

[0010] For example, the stator sleeve can be made of an aluminum material. Compared with the component stiffness of the stator lamellae, the component stiffness of the stator sleeve is reduced, so that the stator sleeve is inevitably adapted to the outer contour of the stator lamellae by pressing into the stator lamellae, and may be deformed. Due to the deformation of the stator sleeve, the positioning and / or alignment of the bolts may be affected by component tolerances. In this context, it is preferred that the bolts are guided to the outside of the housing through the bolt channel on the housing side with a sufficiently large hole gap. The size of the hole gap is preferably such that the bolt position deviation caused by the tolerance can be compensated. Therefore, if necessary, the bolts can be eccentrically passed through the bolt channel to compensate for the tolerance.

[0011] For a secure connection to the stator sleeve, the bolt can have a bolt head with a larger cross-sectional dimension than the bolt shank and can be connected to the stator sleeve. Thus, in the assembled state, the cylindrical bolt channel on the housing side can be clamped between the nut and the bolt head. Furthermore, in the assembled state, the bolt head is in axial pressure contact with the opening edge area of ​​the bolt channel on the housing side with its head bearing surface.

[0012] When the stator sleeve is installed in the motor housing, the opening edge area of ​​the bolt channel on the housing side can be used as a movement stop as follows: During the installation process, the assembly consisting of the stator sleeve and the stator lamination package pressed into it is moved axially into the motor housing, and specifically, until the head bearing surface of the bolt head abuts against the opening edge area of ​​the bolt channel on the housing side. In this state, the bolt passes outward from the bolt channel on the housing side, so that its shank tip can be threadedly connected to the nut on the outside of the housing.

[0013] To increase the torsion resistance, the bolt head can have an anti-torsion contour on its head bearing surface, such as a narrow strip, etc. In the assembled state, the anti-torsion contour can be materially engaged with the opening edge area of ​​the housing-side bolt channel, that is, it can be driven into the material of the motor housing.

[0014] The bolt head can be fixed to the stator sleeve in different ways: In a first embodiment variant, the bolt head can have an external thread, which can engage with an internal thread formed on the stator sleeve. In a second embodiment variant, instead of such a threaded connection, a press connection can be realized, in which the bolt head of the bolt can be pressed axially into a recess of the stator sleeve. Compared with a threaded connection, such a press connection can be realized with a significantly reduced consumption of construction space: Therefore, the recess of the stator sleeve is not realized as a blind hole or the like. Instead, the recess that cooperates with the bolt head in a press-fit manner can be a notch-shaped recess formed in the edge of the stator sleeve. The notch-shaped recess can be axially set back from the edge of the stator sleeve by its groove bottom by a groove depth.

[0015] In the embodiment variant that reduces the structure space especially, the slot-shaped groove made in the stator sleeve edge can be opened radially inwards and radially outwards. In this case, only the slot wall and the bolt head press fit of the slot-shaped groove extending from the groove bottom to the stator sleeve edge.

[0016] Furthermore, the bolt head can be flattened on its radial inner side and radial outer side, thereby forming flat sides. As a result, the two flat sides of the bolt head do not protrude beyond the notch-shaped recess in the stator sleeve, or only protrude beyond the notch-shaped recess in the stator sleeve by a slight excess, thereby saving installation space. Furthermore, the bolt head can have knurling, in particular on its narrow side. In addition to the press fit, the knurling can also engage with the two groove wall materials of the notch-shaped recess formed in the edge of the stator sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The exemplary embodiments of the present invention are described below with reference to the accompanying drawings. In the accompanying drawings:

[0018] Figures 1 to 7 In each case a view of the rotationally fixed stator sleeve in the motor housing is shown. DETAILED DESCRIPTION

[0019] Figure 1 A partial cross-sectional view of the motor in the assembled state is shown to the extent necessary for understanding the invention. The motor thus has a two-part motor housing 1 consisting of two approximately cup-shaped housing parts 3, 5. Figure 1 In the embodiment of the present invention, of the two housing parts 3 and 5, the left housing part 3 is formed by an end wall 7 and a cylindrical peripheral wall 9 adjacent thereto. The peripheral wall 9 transitions to the peripheral wall 13 of the right housing part 5 at the flange connection 11. The stator lamellae 15 is located in the hollow cylindrical motor housing 1, with a stator sleeve 17 in the middle. The stator lamellae 15 is provided with a coil winding 18, which is only schematically shown, and whose winding heads 19 protrude into the winding head space 21 of the motor housing 1, which extends axially between the end wall 7 on the housing side and the end face of the stator lamellae 15. The stator lamellae 15 cooperates with a rotor 22, the rotor shaft 23 of which is rotatably supported on a bearing point 25 of the end wall 7 on the housing side of the left housing part 3.

[0020] like Figure 1 As shown, the stator sleeve 17 is extended in the axial direction by a bolt 27, which is attached to the connection point 29 of the stator sleeve edge 28 with its bolt head 26 by a press fit. The bolt 27 is a rotationally fixed component of the stator sleeve 17 relative to the motor housing 1. In addition, the bolt 27 protrudes beyond the end-side stator sleeve edge 28 ( Figure 3 ).exist Figure 1 In the assembled state shown, the bolt 27 and the matching contour 31 on the housing side ( Figure 1 ) are connected in a form-fitting manner, thereby ensuring that the stator sleeve 17 is rotationally fixed relative to the motor housing 1.

[0021] exist Figure 1 or Figure 2 In the embodiment, the bolt 27 passes through the hollow cylindrical bolt passage 35 on the housing side with its bolt shank 33 with a hole gap s. The bolt passage 35 is formed on the end wall 7 of the left housing part 3. The bolt tip of the bolt 27 is threadedly engaged with the nut 37 on the outside of the housing. Accordingly, the bolt passage 35 formed on the housing part 3 is clamped between the bolt nut 37 and the bolt head 26 of the bolt 27 in the axial direction.

[0022] Due to the limited installation space conditions in the motor housing 1, the torsion resistance must be realized in a manner that saves as much installation space as possible. Against this background, in order to optimize the packaging, the connection point 29 of the bolt head 35 to the stator sleeve edge 28 is realized as follows: the bolt head 26 is thus pressed axially into a recess 39 in the stator sleeve 28. The recess 39 is not provided as a space-intensive blind hole in the stator sleeve edge 28. Instead, according to Figure 4 The recess 39 is realized as a notch-like groove formed in the stator sleeve edge 28. Its groove bottom 41 is set back axially from the stator sleeve edge by the groove depth t.

[0023] The slot wall 43 extends axially from the slot bottom 41 to the stator sleeve edge 28. In the region of the notch-shaped recess 39, the material thickness of the housing part 3 is increased by the dimension d ( Figure 4 ). In addition, the notch-shaped recess 39 is designed to be open radially inwardly and radially outwardly, so that only the groove wall 43 extending from the groove bottom 41 is press-fitted with the bolt head 26 .

[0024] Furthermore, the bolt head 26 is flattened radially inwardly and radially outwardly to form a flat side 45, and the bolt head 26 can only be in press contact with the two groove walls 43 of the notch-shaped recess 39 of the stator sleeve 28 via its narrow side 47. Due to the flattening on both sides, the bolt head 26 advantageously does not protrude radially inwardly or radially outwardly beyond the notch-shaped recess 39 formed in the stator sleeve 17, or only has a slight margin m( Figure 7 ).

[0025] In order to further increase the connection strength between the bolt head 26 and the stator sleeve 17, the bolt head 26 has knurling on its two narrow sides 47, which can engage with the two groove walls 43 of the notch-shaped recess 39. The knurling formed on the bolt head 26 transitions to a shoulder 49 (with a reduced cross section) in the direction of the top side of the bolt head. Figure 5 or Figure 6 ). In the assembled state, it defines together with the groove bottom 41 of the groove 39 of the stator sleeve 17 an intermediate space which serves as a chip collector.

[0026] like Figure 5 As shown, the bolt head 26 has an opening edge region 46 (only in the region of Figure 7 4 ) has an anti-twist contour 51 on the head support surface 44, which is implemented as a narrow strip-shaped protrusion. In the assembled state, the narrow strip-shaped protrusion 51 is materially engaged with the opening edge area 46 of the cylindrical bolt channel 35.

[0027] The following will refer to Figure 7 The process sequence for assembling the electric machine is described: According to this, first a press-in operation is performed, in which the stator lamellae packet 15 is pressed into the stator sleeve 17. Before or after this connection operation, the screw 27 is pressed with its screw head 26 into the notch-shaped recess 39 of the stator sleeve edge 28. This is followed by another connection process, in which the assembly consisting of the stator sleeve 17 and the stator lamellae packet 15 is moved in the direction of the arrow into the left housing part 3, in particular until the head bearing surface 44 of the screw head 26 abuts against the opening edge area 46 of the housing-side screw channel 35. During this insertion process, the screw 27 with its screw shank 33 is also simultaneously guided to the outside through the housing-side screw channel 35.

[0028] It should be noted that the stator sleeve 17 is deformed due to the pressing in of the stator laminations 15, as a result of which the positioning and / or alignment of the bolts 27 is subject to tolerances. Therefore, the size of the hole gap s between the bolt channel 35 and the bolt 27 should be large enough to be able to easily compensate for such tolerances. Therefore, in order to compensate for the tolerances, the bolt 27 can, for example, be passed eccentrically through the bolt channel 35 on the housing side.

[0029] The nut 37 is then screwed onto the screw tip of the screw 27 , whereby the screw channel 35 on the housing side is clamped between the nut 37 and the screw head 26 .

[0030] List of Reference Numerals

[0031] 1 Motor housing

[0032] 3.5 Shell part

[0033] 7 end wall

[0034] 9. Wall

[0035] 11 Flange connection

[0036] 13. Wall

[0037] 15 stator plate group

[0038] 17 stator sleeve

[0039] 18 coil windings

[0040] 19 Winding head

[0041] 21 Winding head space

[0042] 23 Rotor shaft

[0043] 25 storage locations

[0044] 26 bolt head

[0045] 27 bolts

[0046] 28 stator sleeve edge

[0047] 29 connection points

[0048] 31 corresponding contour

[0049] 33 bolt rod

[0050] 35 bolt channel

[0051] 37 Nut

[0052] 39 notch-shaped groove

[0053] 41 slot bottom

[0054] 43 slot wall

[0055] 44 Head support surface

[0056] 45 flat side

[0057] 46 Opening edge area

[0058] 47 narrow side

[0059] 49 Shoulder with reduced cross section

[0060] 51 Anti-twist profile

[0061] aAxial height

[0062] T-slot depth

[0063] d-size

[0064] s hole clearance

[0065] m Radial allowance

Claims

1. An electric motor, comprising a component formed by a stator sleeve (17) and a stator lamination package (15), wherein the stator sleeve (17) is inserted in a rotationally fixed manner into a hollow cylindrical motor housing (1), characterized in that: The stator sleeve (17) is extended in the axial direction by at least one fixing element (27), which in particular protrudes beyond the end-side stator sleeve edge (28) by an axial height (a), and the fixing element (27) is connected to a matching contour (31) on the housing side in a form-locking manner, thereby providing the stator sleeve (17) with a rotational resistance relative to the motor housing (1).

2. The motor according to claim 1, characterized in that The fixing element (27) is a component that is independent of the stator sleeve (17) and can be connected to the stator sleeve (17), and / or the fixing element (27) is a bolt that is threadedly connected to the motor housing (1) via its bolt shaft (33) in the assembled state.

3. The motor according to claim 2, characterized in that The bolt shank (33) of the bolt (27) passes through a cylindrical bolt passage (35) of the motor housing (1) and is threadedly engaged with a nut (37) outside the housing at its bolt tip.

4. The motor according to claim 3, characterized in that The stator sleeve (17) can be deformed by pressing into the stator lamellae (15), whereby the positioning and / or alignment of the bolts (27) is affected by tolerances and / or the bolts (27) are passed through the bolt channels (35) on the housing side, in particular with a hole gap (s), and in particular the size of the hole gap (s) is designed to be large enough to compensate for the tolerances.

5. The electric machine according to any one of claims 2 to 4, characterized in that The bolt (27) has a bolt head (26) which can be connected to the stator sleeve (17), and in particular in the assembled state a housing-side bolt channel (35) is clamped between the nut (37) and the bolt head (26).

6. The motor according to claim 5, characterized in that In the assembled state, the bolt head (26) is in axial pressure contact with the opening edge region (46) of the bolt channel (35) with its head bearing surface (44), and / or in particular during the assembly process, the stator sleeve (17) with the stator lamination package (15) pressed into it can be inserted axially into the motor housing (1) until the head bearing surface (44) of the bolt head (26) abuts against the opening edge region (46) of the bolt channel (35) on the housing side.

7. The motor according to claim 6, characterized in that The bolt head (26) has a torsion-proof contour (51) on its head bearing surface (44), which in the assembled state can be materially joined to an opening edge region (46) of a bolt channel (35) on the housing side.

8. The electric machine according to any one of claims 5 to 7, characterized in that The bolt head (26) has an external thread which can be threadedly engaged with an internal thread of the stator sleeve (17), or the bolt head (26) can be pressed axially into a recess (39) of the stator sleeve (17).

9. The motor according to claim 8, characterized in that The notch (39) of the stator sleeve (17) is a notch-shaped groove formed in the stator sleeve edge (28), and the groove bottom (41) of the notch-shaped groove (39) is set back from the stator sleeve edge (28) by a groove depth (t).

10. The motor according to claim 9, characterized in that The notch-shaped recess (39) is open radially inward and radially outward, so that only the groove wall (43) of the notch-shaped recess (39) extending from the groove bottom (41) to the edge (28) of the stator sleeve can be press-fitted with the bolt head (26), and / or the bolt head (26) is flattened on its radial inner side and radial outer side (45), so that the bolt head (26) does not radially protrude or only protrudes by a slight margin beyond the notch-shaped recess (39) of the stator sleeve (17), and / or the bolt head (26) has knurling, especially on its narrow side (47), which can engage with the groove wall (43) of the notch-shaped recess (39) material.

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