Insulating lamella for an armature of an electric motor, armature and method for assembling the armature

Abstract

Insulating lamella (1, 2) for an armature (10) of an electric motor, having an end face (3) oriented perpendicular to a longitudinal axis (18) from which insulating walls (6, 7) extend, wherein two insulating walls (6, 7) in each case delimit an opening (22) in the end face (3) and are designed to be received in a groove (17) of the armature (10), and wherein the two insulating walls (6, 7) delimiting the opening (22) have a different height (H1, H2) from the end face (3), wherein the height (H1, H2) of the two insulating walls (6, 7) differs by a maximum of 50%, wherein the insulating walls (6, 7) are designed to be elastic in a direction running parallel to the end face (3).

Description

Prior ArtThe invention relates to an insulating plate for an armature of an electric motor according to claim 1.An insulating lamination for an armature of an electric motor is known from DE 10 2006 034 120 A1 of the applicant. The known insulating lamination serves for the electrical insulation of the armature windings with respect to the laminated core formed from laminated laminations, wherein the armature windings are arranged in grooves of the laminated core. For this purpose, the known insulating lamination has two insulating walls for each slot of the laminated core, which walls are aligned perpendicular to a longitudinal axis of the insulating lamination and project from an end face of the laminated core into the respective slot of the laminated core. Furthermore, in the known insulating plate, it is provided that, viewed in the circumferential direction of the insulating plate, the insulating walls assigned to the grooves alternately have a different axial extension. The insulating walls protruding from the end face of the insulating lamination have, on the side facing the laminated core, in each case a delimiting edge which runs perpendicular to the longitudinal axis of the insulating lamination. Furthermore, it is mentioned in the document that the grooves in the laminated core do not have to extend in the axial direction or parallel to the longitudinal axis of the insulating lamination, but rather also enclose an angle and / or can be arranged obliquely in the circumferential direction. Because the boundary edges of the insulating walls of the insulating lamination extend perpendicular to its longitudinal axis, it is necessary to align the insulating walls as exactly as possible with the groove of the laminated core over the entire radial extension of the insulating walls when they are inserted into the respective groove of the laminated core, so that it is possible to insert the insulating walls into the respective groove of the laminated core without any problems. This is relatively difficult, in particular in the case of insulating walls which have a relatively small thickness or rigidity and whose mutual spacing corresponds exactly to the groove width in the laminated core. Although an embodiment is disclosed in FIG. 6 of DE 10 2006 034 120 A1, in which the two insulating walls assigned to a groove in the laminated core have a different height, the difference between the heights of the two insulating walls is, however, so great that threading or aligning the insulating walls having the lower height is very difficult or a large introduction of force and deformation at the other insulating walls is necessary.JP 2005-12 875 A and JP S61-22 164 U disclose insulating masks for a rotor in which a first insulating side wall in a rotor groove is formed axially longer than a second insulating side wall lying tangentially opposite the groove.DE 10 2006 000 307 A1 shows an insulating mask for a stator in which the insulating walls of the stator slot have a smaller axial extent radially on the inside than on the radially outer region. In addition, the insulating walls of different stator slots have different axial lengths.Disclosure of the InventionThe insulating lamella according to the invention for an armature of an electric motor having the features of claim 1 has the advantage that the introduction of the insulating walls into the grooves of the sheet metal packet, in particular in the case of grooves running at an angle, is significantly facilitated.The invention is based on the idea of making possible a simplified alignment and insertion of the insulating walls having a lower height by a relatively small difference in height of the insulating walls assigned to a groove in the armature, since the deformations, which may be required for aligning the insulating walls having the lower height, on the insulating walls having the higher height are relatively small. This also makes it possible, for example, to use insulating walls having a relatively low elasticity or a relatively high rigidity.In order in particular to facilitate the insertion of the insulating walls into a stack of sheets or lamellae, the grooves of which are arranged obliquely with respect to the longitudinal axis, it is provided that the insulating walls are designed to be elastic in a direction running perpendicular to the longitudinal axis. Such an elasticity can be produced particularly easily in particular by the insulating lamella being made of plastic and being formed as an injection-molded part, wherein the insulating walls have a relatively small wall thickness ensuring the elasticity. Moreover, such an insulating plate made of plastic has a high insulating effect and can be manufactured at low cost and with precision.Advantageous refinements of the insulating lamella according to the invention for an armature of an electric motor are listed in the dependent claims.A further advantageous embodiment of the invention provides that the edges of the insulating walls delimiting the insulating walls on the side facing away from the end face extend obliquely, i.e. the height of an insulating wall changes over its extension. The background of this is that in the case of the insulating lamination according to the invention it is sufficient to align the region of the respective insulating wall with the region of the groove in the laminated core which is at the smallest distance from the laminated core or from the groove, i.e. has the greatest height. When axially joining or inserting the insulating walls into the groove, the boundary edge of the respective insulating wall then also slides into the regions which are initially not arranged in the groove, necessarily into the groove, so that the mounting of the insulating lamella, in particular in automated mounting processes, is facilitated or the process safety is increased. Specifically, it is proposed that the insulating walls each have a delimiting edge which, on the side facing or facing away from the longitudinal axis of the insulating lamella, has a greatest distance from the opposite end face of the insulating lamella, and that the distance between the delimiting edge and the end face continuously decreases or increases in the direction of the longitudinal axis.A particularly uniform or uniform introduction of the insulating walls into the grooves of the laminated core can be achieved if the distance of the boundary edge increases or decreases linearly in the direction of the longitudinal axis of the insulating lamination. This enables a uniform rotational angular velocity between the groove and the insulating lamination when the insulating walls are inserted into a laminated core having oblique grooves.The invention also comprises an armature for an electric motor, having a laminated core which is arranged on a shaft in a rotationally fixed manner and is formed from a plurality of lamination laminations, having a plurality of slots which are spaced apart in the circumferential direction and extend in the axial direction and are intended to accommodate an armature winding, and having two axially opposite insulation laminations having insulation walls arranged in the slots, it being provided according to the invention that the slots are formed obliquely in the axial direction, and that an insulation lamination according to the invention is used.Finally, the invention also comprises a method for mounting a last-described armature, wherein the method has at least the following steps: First, a laminated core, which is arranged on a shaft in a rotationally fixed manner and has grooves running obliquely in the axial direction, is provided. An insulating lamella is then threaded onto the shaft. Thereafter, the laminated core and the insulating lamination are moved axially relative to each other, wherein the insulating walls of the insulating lamination having the greater height are aligned with the grooves. The insulating walls having the greater height are then introduced into the grooves. During the insertion, a relative rotation of the laminated core to the insulating walls having the low height may take place, if appropriate, until they are aligned with the grooves. Finally, the laminated core and the insulating lamination are moved axially towards one another until the end face of the insulating lamination comes into contact with the laminated core. Such a method according to the invention has the advantage that it is particularly well suited for the automated assembly of the armature assembly or the armature in a lamination stack with grooves running at an angle.Further advantages, features and details of the invention are evident from the following description of preferred exemplary embodiments and with reference to the drawing.This is shown in: FIG. 1 is a perspective view of an armature arranged on a shaft with an assembled and an unmounted insulating plate; and FIG. 2 is a perspective view of an insulating plate having a plurality of circumferentially spaced insulating walls.Identical elements or elements with the same function are provided with the same reference numbers in the figures.FIG. 1 shows an armature 10 for an electric motor, not shown. The armature 10 is usually arranged rotatably within a stator.The armature 10 has a laminated core 11 which consists of a multiplicity of laminated laminations 12 which are pressed axially against one another. The laminated core 11 or the laminated laminations 12 are preferably fixed in a rotationally fixed manner on a shaft 14 by means of ring caulking. In FIG. 1, a commutator 15 is additionally shown on the shaft 14. A plurality of V-shaped grooves 17 spaced apart in the circumferential direction are introduced into the laminated core 11 or the individual laminated laminations 12. The grooves 17 are formed narrowed at their upper, i.e. in the radially outer region. The slots 17 serve to receive an armature winding, not shown, in particular copper wire (made with an insulating lacquer). In order to insulate the laminated core 11 made of sheet steel from the armature winding, which is not shown, a first insulating lamination 1 and a second insulating lamination 2 are provided.The two insulating laminations 1, 2 are of identical design and are arranged on the laminated core 11 in a shape-conforming manner to one another. Both insulating plates 1, 2 have a flat front side 3 with a wall 4 with a circular contour. In the wall 4, moreover, a (through) hole 5 is formed, which is adapted to the diameter of the shaft 14 and runs in the longitudinal direction of the insulating lamella 1, 2. Insulating walls 6, 7 which are arranged in a V-shape extend from the end face 3 in the direction of the laminated core 11, of which insulating walls 6, 7 each project into a respective groove 17 of the laminated core 11. The insulating walls 6, 7 are adapted to the inner contour of the slots 17 and abut against the slot walls, whereby the slots 17 or the laminated core 11 is insulated from the armature winding. The two insulating walls 6, 7 are integrally connected to one another on the side facing the hole 5 and have a notch 21 in the connecting region on the side facing away from the end face 3. Furthermore, the two insulating walls 6, 7 each delimit an opening 22 on the end face 3, wherein the opening 22 is aligned with the groove 17 of the laminated core 11 facing the insulating lamination 1, 2.It can also be seen from FIG. 1 that the individual grooves 17 in the lamination sheets 12 are arranged offset relative to each other by a small angle of rotation with respect to the shaft 14, so that the grooves 17 of the laminated core 11 as a whole extend at an oblique angle to the shaft 14.The insulating lamella 1, 2 preferably consists of (thin) plastic and is formed as an injection-molded part. The insulating walls 6, 7 extend perpendicular to the plane of the end face 3 and the wall 4 or parallel to the shaft 14, which simultaneously represents a longitudinal axis 18 of the insulating lamella 1, 2. Furthermore, by suitably selecting the plastic or the wall thickness of the insulating walls 6, 7, an elastic configuration of the insulating walls 6, 7 is ensured in a direction perpendicular to the longitudinal axis 18 or parallel to the end face 3.As is shown only in FIG. 2, it can be provided that the wall 4 on the side facing away from the insulating walls is equipped on its radially outer region between the openings 22 with covers 25 arranged concentrically to the hole 5, which cover the first lamination sheets 12 facing them radially.As can best be seen with reference to FIG. 2, the insulating walls 6, 7 have a different H 1, H 2 in a direction running perpendicular to the end face 3, wherein the height H 1 of the side wall 6 is less than the height H 2 of the side wall 7. Furthermore, it is optionally possible that a boundary edge 8 of the side walls 6, 7 arranged on the side facing away from the end face 3 does not run parallel to the end face 3, but at an oblique angle. In other words, this means that the boundary edge 8, viewed in the radial direction to the hole 5, has a height H 1, H 2( or a distance) which changes continuously, preferably linearly. In particular, it is provided that the height H 1, H 2 on the side facing the hole 5 has its greatest value, and that the height H 1, H 2 decreases in the radial direction in the direction facing away from the hole 5. Furthermore, the insulating walls 6, 7 each have, on their side facing away from the hole 5, an end section 23, 24 running in the circumferential direction, in the region of which the boundary edge 8 runs obliquely, i.e. the height in the region of the end section 23, 24 decreases starting from the side facing the insulating wall 6, 7For mounting an insulating lamination 1, 2 in the grooves 17 of the laminated core 11 or the laminated cores 12, it is provided that the corresponding insulating lamination 1, 2 is inserted or threaded with its hole 5 onto the shaft 14 and moved axially in the direction of the laminated core 11. Furthermore, the insulating walls 6, 7 are aligned with the grooves 17. It is essential that the insulating walls 7 having the greater height H 2 are first aligned with the grooves 17. When the insulating lamination 1, 2 and the laminated core 11 are moved axially towards one another, the 7 thus first pass into their respective groove 17.Furthermore, it is provided that the insulating lamination 1, 2 is arranged on the shaft 14 so as to be rotatable with respect to the laminated core 11. By rotating the insulating lamellae 1, 2 with respect to the grooves 17 and thereby optionally taking place elastic deformation of the insulating walls 7 it can thereby be ensured that during the further axial insertion of the insulating walls 6, 7 also the insulating walls 6 having a lower height H 1 securely engage in the region of the grooves 17. As soon as the end face 3 or the wall 4 of the insulating lamination 1, 2 axially abuts the lamination 12 of the laminated core 11 facing it, the assembly process of the insulating laminations 1, 2 on the laminated core 11 is completed.The insulating lamella 1, 2 and the armature 10 described thus far can be modified or modified in a variety of ways without departing from the concept of the invention.

Claims

Insulating lamella (1, 2) for an armature (10) of an electric motor, having an end face (3) which is oriented perpendicularly to a longitudinal axis (18) and from which insulating walls (6, 7) start, wherein in each case two insulating walls (6, 7) delimit an opening (22) in the end face (3) and are designed to be accommodated in a groove (17) of the armature (10), and wherein the two insulating walls (6, 7) delimiting the opening (22) have a different height (H 1, H 2) from the end face (3), wherein the height (H 1, H 2) of the two insulating walls (6, 7) differs by at most 50%, wherein the insulating walls (6, 7) are designed to be elastic in a direction running parallel to the end face (3).Insulating lamella according to Claim 1, characterized in that the height (H 1, H 2) of the two insulating walls (6, 7) differs by a maximum of 10%.Insulating lamella according to Claim 1 or 2, characterized in that the insulating lamella (1, 2) consists of plastic and is designed as an injection-moulded part.Insulating lamella according to one of Claims 1 to 3, characterized in that the insulating walls (6, 7) each have a delimiting edge (8) on the side facing away from the end face (3), which delimiting edge has the greatest height (H 1, H 2) on the side facing or facing away from the longitudinal axis (18), and in that the height (H 1, H 2) of the insulating walls (6, 7) between the delimiting edge (8) and the end face (3) continuously decreases or increases in the direction of the longitudinal axis (18).Insulating lamella according to Claim 4, characterized in that the height (H 1, H 2) of the insulating walls (6, 7) increases or decreases linearly in the direction of the longitudinal axis (18).Insulating lamella according to one of Claims 1 to 5, characterized in that the two insulating walls (6, 7) are arranged approximately in a V shape with respect to one another and have an end section (23, 24) aligned obliquely in the circumferential direction on the side facing away from the longitudinal axis (18).Insulating lamella according to Claim 6, characterized in that the end section (23, 24) is formed obliquely on the side facing away from the end side (3).Insulating lamella according to one of Claims 1 to 7, characterized in that the two insulating walls (6, 7) assigned to an opening (22) are connected to one another on the side facing the longitudinal axis (18) and have, on the side facing away from the end face (3), in the region of the connection, a notch (21) which projects in the direction of the end face (3).Armature (10) for an electric motor, having a laminated core (11) which is arranged in a rotationally fixed manner on a shaft (14) and is formed from a plurality of laminated sheets (12), having a plurality of grooves (17) which are spaced apart in the circumferential direction of the laminated core (11) and run in the axial direction and are intended to receive an armature winding, and having two axially opposite insulating sheets (1, 2) having insulating walls (6, 7) running in the grooves (17), characterized in that the grooves (17) are formed obliquely in the axial direction, and in that the insulating sheets (1, 2) are formed according to one of Claims 1 to 8.Method for mounting an armature (10) which is designed according to Claim 9, comprising at least the following steps: - providing a laminated core (11) which is arranged on a shaft (14) in a rotationally fixed manner and has grooves (17) running obliquely in the axial direction, - threading an insulating lamination (1, 2) onto the shaft (14), - axially moving the laminated core (11) and the insulating lamination (1, 2) towards one another, wherein at least the insulating walls (6, 7) which have a greater height (H 1, H 2) are aligned with the grooves (17), - inserting the insulating walls (6, 7) which have the greater height (H 1, H 2), 7) into the grooves (17) - optionally relative rotation of the laminated core (11) with respect to the insulating walls (6, 7) having the low height (H 1, H 2) until they are aligned with the grooves (17) - axial movement of laminated core (11) and insulating lamination (1, 2) towards one another until the end face (3) of the insulating lamination (1, 2) comes into contact with the laminated core (11).

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