Method for manufacturing an electric machine and electric machine manufactured according to the method

Abstract

The invention relates to a method for producing an electrical machine and an electrical machine produced according to the method, the electrical machine having a stator lamination stack and a stator housing, the stator housing having a receiving opening for receiving the stator lamination stack, the stator lamination stack having a plurality of individual laminations, characterized in that the stator lamination stack is inserted into the receiving opening by means of a punch part in a press-in manner, in particular during the press-in process, a material region of at least one first one of the individual laminations of the stator lamination stack projects radially outwards and, upon press-in, produces a plurality of recesses in a wall portion of the receiving opening, in particular in a bore wall of the receiving opening, the stator lamination stack being held positively in the circumferential direction by means of the recesses, in particular the radially outwards extending recesses.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for producing an electric machine and an electric machine produced according to the method. BACKGROUND

[0002] It is generally known that an electric machine has a stator lamination stack which is received in a stator housing.

[0003] A synchronous electric machine is known from US 2017 / 0 085 138 A1.

[0004] A stator for an electric machine is known from WO 2007 / 107 131 A1.

[0005] A stator of a rotating electric machine is known from DE 10 2014 206 847 A1.

[0006] A motor is known from DE 10 2009 000 621 A1. SUMMARY

[0007] It is therefore an object of the invention to achieve a simple production of an electric machine.

[0008] According to the invention, this object is achieved by the method and the electric machine with the following features.

[0009] In the method for producing an electric machine, an important feature of the invention is that the electric machine has a stator lamination stack and a stator housing, which has a receiving aperture for receiving the stator lamination stack,

[0010] wherein the stator lamination stack has a plurality of individual laminations,

[0011] wherein the stator lamination stack is introduced / inserted into the receiving aperture in a press-in manner, in particular during a press-in process, by means of a punch part,

[0012] wherein a respective material region of at least one first individual lamination of the individual laminations of the stator lamination stack projects radially outwards and, upon press-in, produces a corresponding recess in a wall of the receiving aperture, in particular in an aperture wall of the receiving aperture,

[0013] wherein the stator lamination stack is held in a form-locked manner in the circumferential direction by means of the recess, in particular the radially outwards extending recess.

[0014] The advantage here is that the stator lamination stack is pressed in the axial direction with a tool, i.e. a punch part, which has a small contact surface, so that a material region is displaced / crept / deformed in the radial direction and then scrapes against the stator housing when it enters the receiving bore of the stator housing in the axial direction, i.e. forms a recess which extends in the axial direction. These recesses can be referred to as grooves or slots, respectively, for example. Thus, a form-fit fixing of the stator lamination stack in the stator housing is formed in the circumferential direction.

[0015] Thus, when the stator lamination stack is introduced purely axially, a deformation of the stator lamination stack and thus a radial bulging of a material region of one or more individual laminations of the stator lamination stack can already be caused during the introduction, when the stator lamination stack only generates a counterforce to the pressing-in force caused by friction. This bulging thus already acts before the shoulder of the stator housing is reached, which prevents the stator lamination stack from being pushed further into the receiving bore. Thus, the recess is already cut into the material of the stator housing from the opening, i.e. from the end region of the receiving bore which faces away from the shoulder. In other words, the recess opens out into the environment at the end region of the receiving bore which faces away from the shoulder. After the introduction movement is blocked by the shoulder, the pressing-in force can even be increased slightly in a refinement of the application.

[0016] Thus, the purely axial pushing-in causes a form-fit in the circumferential direction by means of a deformation of the individual lamination of the stator lamination stack which is closest to the punch part, i.e. a first individual lamination or a plurality of first individual laminations, viewed from the punch part.

[0017] In an advantageous design, the punch part has a plurality of pegs which protrude towards the stator lamination stack. The advantage here is that, due to the small contact area, a high pressure can be generated which can cause the desired deformation in the radial direction. However, the radially outwardly protruding material region is arranged in the circumferential direction in a circumferential angular region which includes the circumferential angular region covered by the respective peg. Thus, viewed in the circumferential direction, the radial protrusion is only provided locally.

[0018] In an advantageous design, the pressing-in force is introduced into the stator lamination stack by the pegs when pressing in. The advantage here is that a high pressure can be generated, since the pegs are the only region of the punch part which contacts the stator lamination stack.

[0019] In an advantageous design, the individual pegs are uniformly spaced apart in the circumferential direction, in particular relative to one another. The advantage here is that a uniform force distribution can be achieved.

[0020] In an advantageous design, the stator lamination stack, in particular the individual laminations of the stator lamination stack, are made of a material which is harder than the stator housing. The advantage here is that the cutting-in of the radially protruding material region into the stator housing can be achieved in a simple manner.

[0021] In an advantageous design, the stator lamination stack is made of steel, in particular each individual lamination of the stator lamination stack is made of a steel sheet, and the stator housing is made of aluminum. The advantage here is that the radially protruding material region can be introduced into the stator housing in a simple manner, in particular even with a small pressing force.

[0022] In an advantageous design, the individual laminations are manufactured as stamped parts. The advantage here is that a simple, cost-advantageous manufacture is possible.

[0023] In an advantageous design, the respective peg, when pressed in, produces a respective axially directed recess in the stator lamination stack. The advantage here is that the recess extends in the axial direction.

[0024] In an advantageous design, the stator lamination stack has a plurality of individual laminations that are connected to one another by welding and / or has a plurality of individual laminations that are connected to one another by clamping and / or has a plurality of individual laminations that are connected to one another by stamping stacking / stamping packaging. The advantage here is that a simple manufacture is possible.

[0025] In an advantageous design, the introduction is ended by the shoulder after the stator lamination stack has been brought to bear or has been brought to bear on the radially inwardly protruding shoulder of the stator housing. The advantage here is that an exactly defined end of the introduction is provided.

[0026] In an advantageous design, the radially outwardly directed protrusion is already achieved before the stator lamination stack is brought to bear on the shoulder, and thus only the friction between the stator housing and the stator lamination stack acts as a counterforce against the pressing-in force when pressing in, in particular against the reaction force of the pressing punch component. The advantage here is that the material region already protrudes radially during the period in which the first individual lamination is still surrounded by air, so that the introduction into the material of the stator lamination stack can already be achieved when the first individual lamination enters the precisely manufactured receiving bore relative to the stator lamination stack.

[0027] In an advantageous design, the recess is shaped as a groove and / or a trench. The advantage here is that the recess extends in the axial direction and thus stretches and / or extends in the axial direction more than in the circumferential direction or in the radial direction.

[0028] In an advantageous design, the pressing punch component is removed after the stator lamination stack has been brought to bear on the shoulder. The advantage here is that an axially directed recess remains on the first individual lamination, since the peg of the pressing punch component has been pressed into this first individual lamination. The pressing punch component itself is made of a hard material, in particular of a material that is harder than the material of the individual laminations. A steel that is harder than the steel used to manufacture the individual laminations can also be used as the material of the pressing punch component.

[0029] An important feature in the context of the electric machine manufactured according to the aforementioned method is that the stator lamination stack is positively locked in the circumferential direction in the stator housing,

[0030] wherein each material region protruding radially outward on the stator lamination stack extends into a radially outwardly directed recess, in particular into a groove and / or recess,

[0031] in particular wherein the radial range / area covered by the stator lamination stack overlaps the radial range covered by the stator housing,

[0032] in particular,

[0033] - wherein the net radius of the receiving hole is arranged in the overlapping radial range,

[0034] - and / or wherein the radial range covered by the stator lamination stack comprises the radius of the receiving hole,

[0035] - and / or wherein the radial range covered by the stator housing adjoins the radius of the receiving hole.

[0036] The advantage here is that the positive locking acting in the circumferential direction can be achieved by pure axial press-in. The electric machine can thus be manufactured simply, in particular enabling a loadable connection between the stator housing and the stator lamination stack to be established in a simple manner.

[0037] The invention is not limited to the aforementioned combination of features. Further reasonable combination possibilities of the aforementioned combination of features and / or individual aforementioned features and / or the features explained below and / or the features of the drawing can be derived by the person skilled in the art, in particular from the objects presented and / or by comparison with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0038] The invention will now be explained in detail on the basis of the schematic drawings:

[0039] In Figure 1 the manufacturing method of the stator of the electric machine according to the invention is schematically depicted, wherein the stator lamination stack 3 is pressed onto the lamination stack 3 by means of the punch part 1.

[0040] In Figure 2 a perspective view of the punch part 1 is shown. DETAILED DESCRIPTION

[0041] As shown in the drawings, the punch part has pegs 2 which are uniformly spaced apart from one another in the circumferential direction with reference to the rotational axis of the rotor of the electric machine. These pegs 2 are arranged at the same radial distance, wherein the radial distance is derived with reference to the rotational axis of the rotor.

[0042] The stator lamination stack 3 is designed as a stack of single laminations and is received in a bore of the stator housing 4.

[0043] By means of a press not shown in Figure 1 the punch part 1 is pressed onto the lamination stack 3 in a pressing direction 5, i.e. parallel to the axis of rotation of the rotor, i.e. in axial direction, and thus presses the lamination stack 3 against the shoulder of the stator housing 4. As soon as the lamination stack 3 contacts the shoulder, very high pressing forces can be introduced into the lamination stack 3.

[0044] The forces introduced into the lamination stack 3 before contacting the shoulder, but more precisely after contacting the shoulder, are introduced by the press via the punch part 1 and its pegs 2 protruding towards the lamination stack 3 onto the first single lamination of the lamination stack 3 facing the punch part 1.

[0045] Since there is only a very small contact surface between the pegs 2 and the single laminations, the pressure introduced into the first single lamination is very high. As a result, at least the material region of the first single lamination is displaced in radial direction, in particular already before the lamination stack 3 begins to contact the shoulder.

[0046] Since the stator housing 4 is made of a material that is softer than the lamination stack 3, in particular the single laminations of the lamination stack 3, and the receiving bore for the lamination stack 3 is made in a fitting-accurate manner, the radially outwardly displaced material region of the single laminations cuts recesses, in particular grooves and / or recesses, into the stator housing 4, in particular into the inner wall of the stator housing 4.

[0047] By means of the high pressing forces (Presskraft) introduced into the single laminations via the pegs 2, each peg 2 respectively produces an axially directed recess in the single lamination.

[0048] Since the wall thickness of all single laminations of the lamination stack 3 is very small, the above-mentioned effect applies not only to the first single lamination facing the punch part 1, but also to each single lamination following the first single lamination in the stack. In particular when the pressing forces are chosen appropriately, the first three or more single laminations are deformed.

[0049] The respective circumferential angular region covered by the radially outwardly protruding material region comprises the circumferential angular region covered by the pegs respectively.

[0050] The material regions produced by the respective pegs 2 are spaced apart from one another in circumferential direction.

[0051] The stacking direction is parallel to the axial direction.

[0052] Preferably, the stator housing 4 is made of aluminum and the lamination stack, in particular each single lamination, is made of steel. Here, each single lamination can be produced simply and cost-effectively as a punched part.

[0053] By means of the recesses produced, the stator lamination stack 3 is fixed in a form-locked manner in the circumferential direction.

[0054] Preferably, the individual pegs 2 are uniformly spaced apart from one another in the circumferential direction.

[0055] In other embodiments according to the application, the stack is stamped and bunched, is connected by welding and / or is clamped.

[0056] In other embodiments according to the application, the stack is also connected by adhesive bonding.

[0057] List of reference signs:

[0058] 1 punch part

[0059] 2 peg

[0060] 3 stator lamination stack

[0061] 4 stator housing

[0062] 5 pressing direction.

Claims

1. A method for manufacturing an electric motor, The motor has a stator lamination assembly and a stator housing, the stator housing having receiving holes for receiving the stator lamination assembly. The stator lamination assembly has multiple single laminations. Its features are, The stator laminations are introduced into the receiving hole by pressing in using a punch component. In the stator lamination assembly, at least one of the first laminations has its respective material regions extending radially outward, creating recesses in the wall of the receiving hole upon pressing. The stator laminations are held in a circumferentially locked manner by means of the recess. The punch component has individual pins protruding toward the stator lamination assembly, such that the material region of at least the first single lamination is offset in the radial direction.

2. The method according to claim 1, characterized in that, The recess extends radially outward.

3. The method according to claim 1 or 2, Its features are, During pressing, the clamping force is introduced into the stator lamination assembly through the bolt.

4. The method according to claim 1 or 2, Its features are, The bolts are evenly spaced in the circumferential direction.

5. The method according to claim 1 or 2, Its features are, Each lamination of the stator lamination assembly is made of a material that is harder than the stator housing.

6. The method according to claim 5, Its features are, Each individual lamination of the stator lamination assembly is made of steel plate, while the stator housing is made of aluminum.

7. The method according to claim 1 or 2, Its features are, Single-layer laminations are manufactured into stamped parts.

8. The method according to claim 1 or 2, Its features are, When the corresponding bolt is pressed in, it creates a corresponding axially oriented recess on the stator lamination assembly.

9. The method according to claim 1 or 2, Its features are, The stator lamination assembly has multiple single laminations welded together and / or multiple single laminations clamped together and / or multiple single laminations connected together by stamping and packaging.

10. The method according to claim 1 or 2, Its features are, After the stator laminations are abutted against the radially inwardly projecting shoulder of the stator housing, the introduction is terminated by the shoulder.

11. The method according to claim 1 or 2, Its features are, The radially outward extension is achieved before the stator laminations abut against the radially inwardly projecting shoulder of the stator housing, so only the frictional force between the stator housing and the stator laminations acts as the reaction force against the pressing of the punch components.

12. The method according to claim 1 or 2, Its features are, The concave part is shaped into a groove or channel.

13. The method according to claim 1 or 2, Its features are, After the stator laminations are abutted against the radially inwardly projecting shoulder of the stator housing, the punch assembly is removed.

14. The method according to claim 1 or 2, Its features are, The radial range covered by the stator laminations overlaps with the radial range covered by the stator housing.

15. The method according to claim 14, characterized in that, - The net radius of the receiving hole is arranged in the overlapping radial range. - and / or, the radial range covered by the stator lamination assembly includes the radius of the receiving hole. - and / or, the radius of the radial range covered by the stator housing adjacent to the receiving hole.

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