Motor

Abstract

The invention relates to an electric machine (1), comprising a housing (2) having a receiving chamber (3) and a laminated stator core (4) which is received in the receiving chamber (3) and which is axially supported in the direction of a longitudinal axis (L) of the housing (2) towards an abutment surface (6) of the housing (2), characterized by a cover (7) and by an elastic clamping element (8), wherein the cover is connected to the housing (2) and closes the receiving chamber (3), and the elastic clamping element is arranged on the side of the laminated stator core (4) facing away from the abutment surface (6) and by means of which the laminated stator core (4) is axially clamped against the abutment surface (6) of the housing (2).

Description

Technical Field

[0001] The invention relates to an electric machine, such as an electric motor or a generator for driving a motor vehicle, comprising a housing with a receiving chamber and a stator laminated core received in the receiving chamber and axially supported toward a contact surface of the housing in the direction of the longitudinal axis of the housing. Background Art

[0002] The magnetic flux-conducting structural assembly of such an electric machine usually consists of individual ferromagnetic laminations, wherein the individual laminations are stacked to form a lamination stack. The individual laminations are electrically insulated from one another, for example by means of corresponding coatings. The laminations have a substantially annular or disk-shaped shape. The individual laminations can have gaps or radial slots, wherein the laminations of the lamination stack are usually designed identically and the gaps or slots are aligned with one another in the axial direction. The gaps and slots are used to receive armature windings for inducing an excitation field in an electric motor or absorbing the induced current in a generator, or for receiving permanent magnets.

[0003] The torque generated between the stator and the rotor must be transferred from the lamination stack to other torque-transmitting components, such as from the stator lamination stack to the housing or from the rotor lamination stack to the rotor shaft. For this purpose, it is known to press all the laminations of the lamination stack into the stator housing or onto the rotor shaft with a pressing seat, so that the torque can be transmitted through the pressing seat. It is also possible to provide a form-locking connection between the lamination stack and the torque-transmitting component. The lamination stack is held in or on the corresponding torque-transmitting component with axial prestressing, in order to avoid, in particular, the formation of air gaps between the individual laminations, which may impair the electromagnetic efficiency of the motor or cause noise through vibrating laminations.

[0004] DE 10123224 A1 discloses an electric motor of the type mentioned at the beginning, which has a stator, which is installed in a motor housing. The rotor is rotatably supported in the stator. The stator has a plurality of plate-shaped stator laminations, which are arranged one after the other and are composed of laminations, and which receive an excitation winding. When the electric motor is installed, the individual stator laminations are combined into a lamination stack and then inserted into a prepared receiving portion in the motor housing with radial clearance. In order to ensure a firm connection between the stator and the motor housing, the individual stator laminations are constructed as deformable clamping laminations, which are almost dish-shaped in an unloaded state and radially deform, especially widen, when there is axial force loading. The axial loading is achieved by screws, which pass through a borehole in the lamination stack and are screwed into the bottom of the motor housing. On the side facing away from the base, the screw is supported with the screw head in the axial direction toward the lamination stack, so that the stator laminations, including at least one clamping lamination, are held together in the motor housing in the internal installation position and are fixed relative to the motor housing. As a result of the force load caused by the screw, the clamping laminations are upset in the axial direction and thus expand in the radial direction, so that the clamping laminations are pressed against the surrounding wall in the motor housing. In this way, a fixed fit of the clamping laminations and other stator laminations connected to the clamping laminations via the fixing elements should be achieved. Summary of the invention

[0005] The object of the present invention is to provide an electric machine in which a simple assembly of the stator laminate core is ensured.

[0006] This object is achieved by an electric machine, such as an electric motor or a generator for driving a motor vehicle, comprising: a housing with a receiving chamber; a stator laminate stack, which is received in the receiving chamber and is axially supported in the direction of the longitudinal axis of the housing toward a contact surface of the housing; and a cover, which is connected to the housing and closes the receiving chamber, wherein an elastic clamping element is arranged on a side of the stator laminate stack facing away from the contact surface and wherein the stator laminate stack is axially clamped toward the contact surface of the housing by the elastic clamping element.

[0007] The elastic clamping element thus clamps the stator core stack in the receiving chamber of the housing against the contact surface, so that the stator core stack is securely held in the receiving chamber and, moreover, torque can be transmitted between the stator core stack and the housing by the clamping force. Additional tightening of the stator core stack in the housing is thus superfluous, so that, on the one hand, the number of components used is reduced compared to fixing by means of screws and, on the other hand, the installation expenditure is significantly reduced.

[0008] The cover can be designed in such a way that it serves as an elastic clamping element. This means that the elastic clamping element is an integral component of the cover. However, the elastic clamping element can also be a component separate from the cover, which is arranged between the cover and the stator laminated core and is axially clamped.

[0009] The clamping element can be a disc spring or a wave spring which can be elastically deformed in the axial direction with a spring force. Thus, a simple component is provided in order to hold the stator laminated core in the receiving chamber.

[0010] According to an exemplary embodiment, the cover has an annular gap or step on the end side in the direction of the receiving chamber, and the clamping element is received inside the gap or step. The annular gap or step can form a surrounding flange protruding in the axial direction radially outward, which is used to receive the clamping element. As a result, the clamping element is fixed relative to the cover in the radial direction. In addition, the clamping element can be fixed to the cover in the axial direction. For this purpose, the clamping element can be connected to the cover in a material-locking manner, such as by bonding, or a form-locking element can be provided, so that the clamping element can be locked to the cover.

[0011] The cover can have a sleeve section which is axially sunken into the receiving chamber of the housing and against which the clamping element is supported. This ensures that the cover is centered relative to the housing. If the cover has an annular recess or step as described above, this recess or step can be arranged at the end in the sleeve section.

[0012] Preferably, the cover is screwed onto the housing in the axial direction. Thus, the clamping force of the clamping element is applied via the screw connection or the clamping element is pre-tensioned.

[0013] The cover can have a flange section which is supported axially toward the housing and is arranged in a fastening hole, wherein a fastening screw is passed through the fastening hole and is screwed into a threaded hole in the housing.

[0014] According to a possible embodiment, the stator laminate core has a plurality of laminates which are arranged one above the other along a longitudinal axis. The laminates can be designed essentially in the shape of a disk and have recesses or radial slots, for example to receive armature windings or permanent magnets for generating an excitation field.

[0015] The laminations can be supported in a form-fitting manner toward the housing in the circumferential direction. For example, the laminations can have radially protruding projections or protrusions, which engage in correspondingly shaped grooves in the housing. Likewise, the housing can have inwardly protruding projections, which engage in grooves of the laminations that are aligned with one another. As a result, the laminations and thus the stator lamination stack are supported in a form-fitting manner toward the housing in the circumferential direction, so that possible torque peaks can be transmitted between the stator lamination stack and the housing.

[0016] Furthermore, a rotor shaft having a rotor core can be received in the receiving chamber, wherein the rotor shaft is rotatably supported on the one hand via a rotary bearing in the housing and on the other hand via a rotary bearing in the cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] A preferred embodiment will be explained in detail below with the aid of the accompanying drawings. In this regard:

[0018] Figure 1 shows a longitudinal section through an electric machine according to the invention;

[0019] Figure 2 shows an enlarged cutout of another embodiment of a cover and a resilient clamping element; and

[0020] Figure 3 The exploded view in perspective shows the Figure 1 The cut-off part of the motor. DETAILED DESCRIPTION

[0021] Figure 1 and 3 An electric machine 1 according to the invention, here in the form of an electric motor for driving a motor vehicle, is shown in various illustrations and is described together below. The electric machine 1 has a housing 2, in which a receiving chamber 3 extending along the longitudinal axis L of the housing 2 is formed. A stator lamination stack 4 is arranged in the receiving chamber 3, which is axially supported in the direction of the longitudinal axis L toward a contact surface 6 of the housing 2. The contact surface 6 is arranged in a plane perpendicular to the longitudinal axis L. In order to receive the stator lamination stack 4, the housing 2 has an at least substantially cylindrical receiving section 24.

[0022] The stator laminated core 4 has a plurality of laminated cores 5 which are arranged in a Figure 1 The lamination stacks 5 are arranged one on top of the other along the longitudinal axis L within the overall length of the stator lamination stack 4 and each have a thickness as indicated on the right. The individual laminations 5 are electrically insulated from one another, for example by means of corresponding coatings.

[0023] The receiving chamber 3 is closed by a cover 7 which is screwed to the housing 2. On the side of the stator core 4 facing away from the contact surface 6, a resilient clamping element 8 is arranged in an axially clamped manner between the cover 7 and the stator core 4. It is also conceivable that the resilient clamping element 8 is an integral component of the cover 7. The cover 7 then not only assumes the function of closing the receiving chamber 3 but also clamps the stator core 4 axially against the contact surface 6.

[0024] By axially clamping the stator core 4 against the contact surface 6, it is ensured that there is a sufficiently large frictional connection between the stator core 4 and the housing 2 so that a torque can be transmitted between the stator core 4 and the housing 2. The core 5 can be received in the receiving chamber 3 with radial play. In order to be able to transmit possible torque peaks, for which the frictional connection may not be sufficient, it can be provided that the stator core 4 is radially clamped in the receiving chamber 3, thereby causing a further frictional connection in the radial direction. As a supplement or alternative, it can also be provided that the core 5 is supported in a form-locking manner against the housing 2 in the circumferential direction. In this case, for example, the core 5 can have radially protruding projections, which are embedded in correspondingly shaped grooves in the housing 2. Similarly, the housing 2 can have inwardly protruding projections, which are embedded in grooves of the core 5 that are aligned with each other.

[0025] Furthermore, the clamping of the stator laminated core 4 ensures that the individual laminated cores 5 are clamped against one another and that no air gaps are formed between the laminated cores 5 which could impair the electromagnetic efficiency of the electric machine 1 .

[0026] The clamping element 8 is designed in the manner of a disc spring and has an axially elastic spring section 9, which is supported toward the stator laminated core 4. On the side facing away from the stator laminated core 4, the clamping element 8 has a retaining section 10, with which the clamping element 8 is retained on the cover 7. The spring section 9 tapers in a truncated cone-shaped manner in the longitudinal section starting from the retaining section 10 in the direction of the stator laminated core 4. The spring section 9 can also have any other type of disc spring and taper, for example, in an arc shape (such as in Figure 2 In principle, it is also possible not to provide the retaining section 10 and the entire clamping element 8 can be configured to be thinner. In addition, it is also possible to envision other axially elastic elements, such as, for example, wave springs, which are configured to be wavy in the circumference.

[0027] In accordance with Figure 2 In the embodiment of the cover 7, the cover 7 has an annular recess 11 in the form of a step, which forms a circumferential flange 12. The holding section 10 of the clamping element 8 is arranged radially inside the flange 12 and is thus centered relative to the cover 7 about the longitudinal axis L. The clamping element 8 can be materially bonded to the cover 7, for example by gluing, or can be latched to the cover 7 by latching elements. The cover 7 and the clamping element 8 can thus form a preassembled structural unit.

[0028] In order to fix the cover 7, it has a sleeve section 13, which is sunk into the receiving chamber 3 and centers the cover 7 relative to the housing 2. In addition, the cover 7 has a flange section 14, which is supported axially toward the housing 2. In the flange section 14, a fixing hole 15 is arranged, through which a fixing screw 16 is passed, wherein the fixing screw 16 is screwed into a threaded hole 17 of the housing 2. As a result, the clamping element 8 can be clamped by the cover 7 by means of the fixing screw 16 when the cover 7 is mounted on the housing 2.

[0029] The core plates 5 of the stator core plate 4 are substantially disk-shaped and form a central passage 18 for receiving a rotor shaft 19 having a rotor core plate 20 fastened thereto. The rotor shaft 19 is rotatably supported about a longitudinal axis L in the housing 2 by a first rotary bearing 21 in the form of a rolling bearing and, on the other hand, in the cover 7 by a second rotary bearing 22 in the form of a rolling bearing.

[0030] The rotor shaft 19 is designed as a hollow shaft, into which a connecting shaft 23 is inserted on the side facing away from the cover 7, wherein a rotationally fixed connection is established between the rotor shaft 19 and the connecting shaft 23. The connecting shaft 23 is rotatably supported in a transmission housing 25 connected to the housing 2 via a third rotary bearing (not shown here), for example in the form of a rolling bearing. The connecting shaft 23 serves to drive a transmission stage, not shown in detail here, in order to drive a motor vehicle, for example.

[0031] List of reference numerals:

[0032] 1 Motor

[0033] 2 Housing

[0034] 3 Reception Room

[0035] 4 Stator lamination stack

[0036] 5. Lamination

[0037] 6 Abutment surface

[0038] 7 Cover

[0039] 8 Clamping element

[0040] 9 Spring section

[0041] 10 Keep Section

[0042] 11 Gap

[0043] 12 Flange

[0044] 13 Sleeve section

[0045] 14 Flange section

[0046] 15 Fixing holes

[0047] 16 Fixing screw

[0048] 17 Threaded holes

[0049] 18 channels

[0050] 19 Rotor shaft

[0051] 20 Rotor lamination pack

[0052] 21 First rotary bearing

[0053] 22 Second rotary bearing

[0054] 23 Connecting shaft

[0055] 24 Acceptance section

[0056] 25 Transmission housing

[0057] L Longitudinal axis

Claims

1. A motor (1), comprising: A housing (2) with a receiving chamber (3) and a stator lamination stack (4), which is received in the receiving chamber (3) and is axially supported in the direction of the longitudinal axis (L) of the housing (2) towards a contact surface (6) of the housing (2), Features A cover (7) and an elastic clamping element (8), wherein the cover is connected to the housing (2) and closes the receiving chamber (3), and the elastic clamping element is arranged on the side of the stator laminated core (4) facing away from the abutment surface (6) and the stator laminated core (4) is axially clamped toward the abutment surface (6) of the housing (2) by means of the elastic clamping element.

2. The electric machine (1) according to claim 1, It is characterized in that The elastic clamping element (8) is axially clamped between the cover (7) and the stator laminated core (4).

3. The electric machine (1) according to claim 1 or 2, It is characterized in that The clamping element (8) is designed as a disc spring or a wave spring.

4. The electric machine (1) according to any one of claims 1 to 3, It is characterized in that The cover (7) has an annular recess (11) or step on the end side in the direction of the receiving chamber (3), in which the clamping element (8) is received.

5. The electric machine (1) according to any one of claims 1 to 4, It is characterized in that The cover (7) has a sleeve section (13) which is recessed axially into a receiving chamber (3) of the housing (2) and against which the clamping element (8) is supported.

6. The electric machine (1) according to any one of claims 1 to 5, It is characterized in that The cover (7) is screwed onto the housing (2) in the axial direction.

7. The electric machine (1) according to any one of claims 1 to 6, It is characterized in that The cover (7) has a flange section (14) which is supported axially toward the housing (2) and is arranged in a fastening hole (15), wherein a fastening screw (16) is passed through the fastening hole (15) and is screwed into a threaded hole (17) of the housing (2).

8. The electric machine (1) according to any one of claims 1 to 7, It is characterized in that The stator laminate core (4) has a plurality of laminated cores (5) which are arranged one above the other along a longitudinal axis (L).

9. The electric machine (1) according to claim 8, It is characterized in that The core stack (5) is designed in the shape of a disk.

10. The electric machine (1) according to claim 8 or 9, It is characterized in that The core plates (5) are supported in a form-fitting manner in the circumferential direction towards the housing (2).

11. The electric machine (1) according to any one of claims 1 to 10, It is characterized in that A rotor shaft (19) having a rotor core (20) is received in the receiving chamber (3), wherein the rotor shaft (19) is rotatably supported in the housing (2) via a first rotary bearing (21) on the one hand and in the cover (7) via a second rotary bearing (22) on the other hand.

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