EP0944938B1 - Commutator with reinforcing ring - Google Patents

Abstract

A commutator (10, 110, 210) with a reinforcing system comprising a stepped insulating ring (20, 120, 220) with a support piece (22, 122, 222) and a center or flange piece (24, 124, 224) and a metal ring (18,118, 218) which has a rectangular cross-section and is fitted into the stepped shape of the insulating ring such that part of the radial outer surface of the metal ring abuts the radial inner surface of the center or flange piece, and the end inner surface of the metal ring completely abuts the end outer surface of the support piece.

Description

The invention relates to a commutator according to the preamble of claim 1 with embedded in molding material Copper segments that have one in at least one receptacle Armoring ring arranged coaxially to the commutator rotation axis record that from a metal ring as well an insulating ring joined to the metal ring consists. The invention further relates to a method according to the preamble of claim 9 for the manufacture of a such commutator, in which one of copper segments existing body with at least one receptacle for one consisting of a metal ring and an insulating ring Reinforcement ring made, the reinforcement ring on this Shot applied and the commutator then with Press material is poured.

Various types of commutators are known which are reinforced with fiberglass reinforcement rings. Despite the great advantages of these commutators - for example the glass fiber ring has an advantageous elongation characteristic on and can be easily pretensioned or braced, further fiberglass rings can be attached to the copper holding anchor slide on directly because the reinforcement rings are also electrical Isolators are - such commutators have a weakness compared to those reinforced with steel rings Switchboards. This weakness manifests itself in the application of these commutators for highly heat-loaded motors or at Long-term operation under high temperature influences. Is too it is possible that due to some error Heat overload comes. With all heat overloads local softening of the insulation ring or Glass fiber rings occur when inexpensive resins be used. As a result, the commutator segments shift beyond the tolerance values can, reducing the life of such commutators is significantly reduced.

Commutators have therefore already been proposed where the reinforcement ring consists of at least one in cross section essentially rectangular metal ring consists of one in cross section essentially rectangular insulating ring is added. Such one The commutator is, for example, from DE-A-4302759 known. This document discloses a commutator for an electric motor with a fan-shaped distribution around the circumference Copper lamellae with undercuts Inner bars in an insulating carrier made of a plastic molding compound are anchored. At least there is one a reinforcement ring in the metal Carrier included, the inner webs on extensions in the Grips the area of the undercuts and at least on its inside facing the extensions is an insulating one Has liner. There is the intermediate layer from a support ring that fits the clamping ring a pressure-resistant and even at high working temperatures insulating material.

Since a press fit is specified between the clamping ring and the support ring is, which makes the clamping ring and the support ring a rigid and form a solid unit as a reinforcement ring, both must Rings before their composition with highly precise dimensions and therefore very much. tight manufacturing tolerances so that both always the same pressing force between the two rings as well as a corresponding accuracy of fit can be ensured in the undercuts. In addition, in the case where the support ring is made of glass there is a preload to enable the press fit can only be produced with great effort. Further is possible that this with a version with fiberglass ring can be softened at a high temperature if inexpensive, not heat-resistant Hartz is used, which at least damage this from the fiberglass ring and a metal ring existing reinforcement ring can lead. Furthermore, the between the hub and insulation ring or glass ring arranged in the metal ring its built-in state in the commutator no longer be biased.

A commutator specified in the preamble of claim 1 Art is from WO-A-95/22184 and WO-A-95/22185 known. These publications deal with the Making one out of a metal ring and a glass fiber ring assembled armoring ring for commutators. A metal ring with a rectangular cross section is created at the front into a rectangle that is initially rectangular in cross section Fiberglass ring pressed in; this deforms the glass fiber ring step-shaped such that a The protruding area is created, which is offset from the metal ring and rests on a radial outer surface of the metal ring, which creates a centering or flange part. The The generic state of the art is the 3 and 6 of WO-A-95/22184 and Figs. 3 and 7 of WO-A-95/22185 represents. It is important that the Space between the metal ring and the retaining anchor Copper segments are filled with molding material. Other than this applies to the prior art according to DE-A-43027159, thus presses a first part of the radial outer surface the holding anchor via a pressure-resistant at high temperatures Intermediate layer of the press material on the metal ring of the Reinforcing ring.

The present invention is based on the object specify a commutator of the type mentioned at the beginning, which with technically simple means both at high Working temperatures as well as at high speeds has further improved torsional strength, at the same time is easy to manufacture and also has the advantages of Strain behavior of the insulation ring can exploit. The Another object of the invention is a method of the type mentioned at the beginning indicating the manufacture one both under high temperatures and under high ones Speeds in terms of its torsional strength enables improved commutator and at the same time Manufacturing process extremely simplified.

This task is done with a commutator according to the generic term of claim 1 and a manufacturing method according to solved the preamble of claim 9 in that the Support part of the insulating ring has a smaller inner diameter has than the metal ring and that one in axial Direction towards the first part of the radial outer surface the holding anchor connecting second part the support part the insulating ring independently.

It is therefore essential for the commutator according to the invention that that the supporting part of the insulating ring due to its opposite the metal ring of smaller inner diameter on its total axial extent directly on the radial The outer surface of the holding anchor rests. In this way the result is an optimized multiple reinforcement system in such a way that the metal ring and the supporting part of the Isolation ring are ideally separated in terms of position; everyone Part of the radial outer surface of the retaining anchor carries the other part completely independent, everyone on his axial height of the retaining anchors functionally the force that from the effect of the centrifugal force of the copper segments evident. This results in a high level Temperatures and at high speeds further improved Torsional strength of the commutator; in particular is the Danger that the glass fiber ring when installing the Commutators and / or breaks in operation, practical eliminated.

The manufacturing method according to the present invention uses the particularly advantageous manufacturing method of the reinforcement ring at least by compressing at the front one essentially rectangular in cross section Metal ring with an initially in cross section essentially rectangular insulating ring such that the insulating ring seen from the inside out in the axial direction a supporting part and a radially outside of it subsequent and axially offset centering or flange part exists, the two integrally formed with each other are and have a step shape that the metal ring thus fitted into the step shape of the insulating ring is that at least part of the radial outer surface of the Metal ring on the radial inner surface of the flange part and an end face of the metal ring completely on one End face of the support part rests.

The solutions according to the invention also have the Advantage that only about each for the assembled ring half of the usual axial heights of the insulating ring and the steel or metal ring is used, what leads to considerable material savings. Since both the metal ring and the insulating ring are included relatively large dimensional tolerances are manufactured manufacturing costs for the reinforcement ring drastically lowered.

A particularly preferred and inexpensive variant is given that the insulating ring is a glass fiber ring and still inexpensive and therefore not extremely warm. heat resistant resins can be used.

Except for flat commutators, it is necessary to use both To provide such a reinforcement on the end faces of the commutator.

It is also advantageous if only the supporting part of the Isolierringes on the radially outward facing part of the Retaining anchor is biased regardless of the metal ring. This can be achieved, for example, in that this outward-facing area of the radial outer surface the holding anchor is inclined to the axis of rotation is.

Although the foregoing description is essentially a normal lamellar commutator (drum or roller commutator) relates, the invention is not limited to one limited such commutator. That's how it is possible, the solution according to the invention on a flat commutator apply, i.e. it can be the same reinforcement ring used and consistent in the recording be embedded.

According to a further embodiment, it is also possible that the metal ring is annular and has a coaxially extending groove in which the engages part abutting the metal ring. This training is particularly cheap for flat commutators. Because This shape of the metal ring causes the flat commutator to tilt effectively prevented.

It is also advantageous here if the insulating ring is stepped formed with a support part and a flange part is, the flange part axially offset in the groove of the Metal ring engages, the space between the inner circumferential surface of the metal ring and that of the axis of rotation Adjacent arranged from copper segments with pressed material is filled, which is a part of the insulating body of the flat commutator is.

The metal ring is very easy to manufacture, for example by is punched out of a sheet. This is due to the low axial height of the metal ring possible. The metal ring can also be from a metal tube be cut to length. Here, too, is the comparatively low one axial height is advantageous because it is made of a metal tube more metal rings can be separated with a given length can.

So that this advantage is not lost, but still further increased, the insulating ring is preferably used as a glass fiber ring produced by winding accordingly of glass fibers with the addition of synthetic resin or by separation is made from a glass fiber tube.

It is also possible to use a glass fiber tube here that then with the formation of glass fiber rings with less axial height can be cut to length.

It is also possible that the metal ring is formed in the form of an annular disk and is coaxial extending groove, in which the on the metal ring adjacent part can intervene when pressed together. there the cross section of this metal ring is higher Section modulus.

Although a variety of ways to manufacture this groove are present, it is preferred for reasons of cost, punch the groove in the metal ring in such a way that an annular one on the opposite side of the metal ring Process arises.

Another advantage of the commutator according to the invention is that the reinforcement ring on both sides of the ring can be directly based on the copper segments. The allows the armoring ring to be inserted into the grooves of the copper segments to hit directly or in the case of a flat commutator to slide onto the seat, taking the reinforcement ring attaches itself to the copper segments and the Copper segments thereby aligned in precise radial positions can be.

An additional advantage of this commutator according to the invention is that only the support part of the insulating ring is biased independently of the metal ring.

Other advantageous embodiments of the invention are shown in further subclaims specified.

Fig.1

einen Teilquerschnitt durch einen Kommutator mit einem Armierungsring gemäß einer ersten erfindungsgemäßen Ausführungsform;

Fig.2

einen Teilquerschnitt durch einen Plankommutator mit dem gleichen in Fig.1 gezeigten Armierungsring; und

Fig. 3

einen Teilquerschnitt eines Armierungsringes gem. einer zweiten Ausführungsform.

The invention is explained in more detail below on the basis of preferred embodiments with reference to the drawings. Show it:

Fig.1

a partial cross section through a commutator with a reinforcement ring according to a first embodiment of the invention;

Fig.2

a partial cross section through a flat commutator with the same armoring ring shown in Figure 1; and

Fig. 3

a partial cross section of a reinforcement ring acc. a second embodiment.

1 shows a partial cross section through a commutator 10, whose copper segments 26 are cast in a molding material 12 or are embedded and about an axis of rotation 14 in Operation of the commutator 10 can rotate.

To increase the torsional strength, the commutator 10 is at least on one, preferably on both ends with a reinforcing ring 16, which consists of a metal ring 18th and an insulating ring 20. The reinforcement ring 16 from a receptacle present in the copper segments 26 15 added. The receptacle 15 is in this embodiment groove-shaped and is formed by undercuts formed in the individual copper segments 26. Although several Embodiments for such an insulating ring available are, a glass fiber ring 20 is preferred as an insulating ring.

The copper segment 26 points on its axis of rotation 14 facing side a retaining anchor 28 which is part of the Recording 15 for the reinforcing ring 16 forms.

As can be seen from FIG. 1, the glass fiber ring 20 is of this type built up in steps that it has a supporting part 22, which bears against the radial outside of the holding anchor 28, as well as at the base of the receptacle 15. In the example shown in Figure 1, the support member 22 is only on the radial outside of the holding anchor 28.

A centering or flange part is connected to the support part 22 24 of the glass fiber ring 20 in such a way that this flange part 24 is axially offset to the support member 22 and thus one Has step shape. Furthermore, the radial outside of the Flange portion 24 on the radially inward surface of the copper segment 26.

In that formed from the support member 22 and the flange member 24 Stage, the metal ring 18 is received so that its radial Outer surface partially abuts the flange part 24, while its axially inward face surface lies completely against the support part 22. Between the radial inner surface of the metal ring 18 and the radial An outer surface of the holding anchor 28 forms a space is, this can be done with an intermediate layer 30 made of pressed material 12 must be completed.

As shown in Figure 1, the axial outer surface forms of the anchor 28 seen from the outside inwards a first Part a, through which the holding anchor 28 by means of at high temperatures pressure-resistant intermediate layer 30 of the molding material 12 presses on the metal ring 18 while an inside of it subsequent second part b essentially on the radial Inner surface of the support member 22 abuts.

2 shows a partial cross section of a flat commutator 110 depicting a second embodiment of the invention forms, however, the reinforcement ring shown in Fig.1 used. In Fig.2, those with the one shown in Fig.1 were Embodiment same parts with the same, however Reference number increased by 100 to aid understanding facilitate.

The flat commutator 110 shown in FIG. 2 consists of a cross section L-shaped copper segments 126, with the brush tread perpendicular to a rotation axis 114 of the face commutator 110 runs. Run parallel to the axis of rotation 114 Retaining anchors 128 of the copper fins 126 that together form a receptacle 115 for a reinforcement ring 116.

The reinforcing ring 116 is made up of an insulating ring 120 and a Metal ring 118 formed. It also consists in this Example of the insulating ring 120 made of a glass fiber ring.

Again, the glass barrel ring 120 consists of a supporting part 122, which is on both the inward surface of the Holding anchors 128, as well as on the brush tread facing away Surface of the copper segment 126 rests.

Similar to FIG. 1, the glass fiber ring 120 is also of 2 shows a centering or flange part 124 axially offset, that the glass fiber ring 120 is a stage for receiving a Metal ring 118 forms.

Again, a first part a and also a second part Part b, which correspond to the same areas of Figure 1, over which the centrifugal force of the holding armature 128 transferred to the metal ring 118 or the glass fiber ring 120 becomes. In addition, the face commutator 110 is made of pressed material 112 potted or pressed.

3 shows a further embodiment of an inventive Commutators, here flat commutators 210, shown a reinforcing ring 216 in a receptacle 215 having. Furthermore, the same will be increased, but by 100 Reference numbers from Fig.2 used.

In contrast to the metal rings 18 and 118 of FIGS. 1 and 2 the metal ring 218 of the third embodiment has one changed form on that it was designed in the form of an annular disk and is coaxial with the axis of rotation 214 and groove 234 facing the brush tread, in which is part of a centering or flange part 224 of a Isolating ring 220 engages.

From this Figure 3 it can be seen that the metal ring 218 a the groove 234 has opposite extension 236, the one Tilting of the flat commutator 210 prevented.

Similar to Figure 1 is also in the embodiments 2 and 3 are each pressure-resistant at high temperatures Intermediate layer 130 and 230 formed from the pressed material 112 or 212 exists.

It can be clearly seen from FIG. 3 that the support part 222 the flange part 224 adjoins in a stepped, axially offset manner, whose cantilevered area engages in the groove 234. The section adjoining the flange part 224 radially on the outside the metal ring 218 is used for additional support the sections of the copper segments forming the brush running surface 226. This also increases the surface area which can adhere to the Pressstoff212.

The following is the method of manufacture according to the invention of these commutators 10, 110 and 210 described. at this manufacture is made of copper segments 26, 126 and 226 existing body with at least one seat for one from a metal ring 18, 118 and 218 and an insulating ring 20, 120 and 220 existing reinforcement ring 16, 116 and 216 manufactured. Then the reinforcement ring 16, 116 and 216 applied to this seat and the commutator 10, 110 and 210 then cast or pressed with molding material 12, 112 and 212.

The reinforcement ring 16, 116 and 216 is produced by compressing at least one cross-section at the end essentially rectangular metal ring 18,118 and 218 with the substantially rectangular cross section Isolierring 20,120 and 220. This happens so that at least one flange part 24, 124 and 224 of the insulating ring 20, 120 and 220 in the axial direction of the commutator 10, 110 and 210 is moved from the inside out and the metal ring 18, 118 or 218 on its radial outer surface or engages in the groove 234.

The production of the metal ring is preferably so performed that a corresponding metal ring from a sheet 18,118 is punched out. This is possible because the axial height of the metal rings 18, 118 and 218 comparatively is low. Furthermore, the metal ring 18, 118 and 218 can also be cut to length from a metal pipe, due to the low axial height comparatively more metal rings 18,118 and 218 can be separated from a pipe of given length.

The production of the insulating ring is also very simple, in particular if a glass fiber ring 20, 120 and 220 is used. This glass fiber ring 20, 120 and 220 can either by appropriate winding of glass fibers under Supply of synthetic resin or by removing an appropriate one Piece of a fiberglass tube, here, too, due to the low axial height Glass fiber rings separated from the glass fiber tube with a given length can be.

The reinforcement ring 16, 116 and 216 is produced by simply pressing the previously together with the corresponding ones End faces collapsed rings, without any exert axial tension. The two rings are just moved axially relative to each other, the corresponding Flange part 24, 124 and 224 of the former rectangular Cross section of the glass fiber ring 20, 120 or 220 usually shifted relative to the metal ring 18, 118 or 218 becomes.

Claims (14)

1. Commutator (10; 110; 120) with copper segments (26; 126; 226) embedded in moulded material (12; 112; 212) which hold a reinforcing ring (16; 116; 216), consisting of a metal ring (18; 118; 218) and an insulating ring (20; 120; 220) fused with the metal ring (18; 118; 218) arranged coaxially to the commutator rotation axis (14; 114; 214), in at least one location (15; 115; 215), the stepped insulating ring (20; 120; 220) consisting of a carrier part (22; 122; 222) and a radially adjacent and axially offset centering or a flange part (24; 124; 224), both being formed together in one part, the metal ring (18; 118; 218) being furthermore fitted in the stepped shape of the insulating ring (20; 120; 220) that part of the radial outer face of the metal ring (18; 118; 218) bearing on the radial inside face of the flange part (24; 124; 224) and an end face of the metal ring (18; 118; 218) on an end face of the carrier part (22, 112, 222), whereby the reinforcing ring (16; 116; 216) forms a multiple reinforcing system in which the metal ring (18; 118; 218) and the carrier part (22; 122; 222) of the insulating ring (20; 120; 220) are separated position-wise and independent of each other, each of them bearing the functional force produced by the effect of the centrifugal force of the copper segments (26; 126; 226) at its axial height of the holding armatures (28; 128; 228), whereby a first part (a) of the radial outer surface of the holding armatures (28; 128; 228) presses onto the metal ring (18; 118; 218) through the intermediate layer (30; 130; 230) of the moulded material (12; 112; 212) which is resistant to compression at high temperatures, characterised in that the carrier part (22; 12; 222) of the insulating ring (20; 120; 220) has a smaller inside diameter than the metal ring (18; 118; 218) and that a second part (b) of the radial outside surface of the holding armatures (28; 128; 228) adjoining in the axial direction carries the carrier part (22, 122; 222) of the insulating ring (20; 120; 220) on its own.
2. Commutator (10; 110; 210) according to Claim 1, characterised in that the commutator is a flat commutator (110; 210).
3. Commutator (210) according to Claim 2, characterised in that the metal ring (218) is annular and has a coaxially extending groove (234) into which the flange part (224) adjacent to the metal ring (218) engages and that an annular extension (236) is formed on the side of the metal ring (218) opposite to the grove (234).
4. Commutator (10) according to Claim 1, characterised in that it is designed as a barrel commutator wherein two reinforcing rings (16) are provided each of them arranged in an end locator (15).
5. Commutator according to Claim 4, characterised in that viewed in the axial direction, the carrier parts (22) of the insulating parts (20) are arranged inside and the centering or the flange parts (24) outside.
6. Commutator (10; 110; 210) according to at least one of the above Claims, characterised in that to form the reinforcing rings (16; 116; 216), the metal ring (18; 118; 218) and the insulating ring (20; 120; 220) are joined together by shifting the metal ring axially into the insulating ring with an originally rectangular cross section while forming the centering or flange part (24; 124; 224).
7. Commutator (10; 110; 220) according to at least one of the above Claims, characterised in that only the carrier part (22; 122; 222) of the insulating ring (20; 120; 220) is preloaded by the part of the holding armature (28; 128; 228) pointing radially to the outside, independent of the metal ring (18; 118; 218).
8. Commutator (10; 110; 210) according to at least one of the Claims 1 to 7, characterised in that the insulating ring is a fibreglass ring (20; 120; 220).
9. Method of producing a commutator (10; 110; 210) according to Claim 1 or 2 whereby a body consisting of copper segments (26; 126; 226) is made with at least one location (15; 115; 215) for a reinforcing ring (16; 116; 216) consisting of a metal ring (18; 118; 218) and an insulating ring (20; 120; 220), the reinforcing ring (16; 116; 216) being placed in this location (15; 115; 215) and the commutator (10; 110; 210) being subsequently poured over with the moulding material (12; 112; 212) and the reinforcing ring (16; 116; 216) being produced by compressing from the front face at least one metal ring (18; 118; 218) with an insulating ring (20; 120; 220) which has in the main a rectangular section in such a way that the stepped insulation ring (20; 120; 220) consists of a carrier part (22; 122; 222) and a radially adjoining to the outside and axially offset centering or flange part (24; 124; 224), the two being made in one piece with one another, the metal ring (18; 118; 218) furthermore matched to the stepped shape of the insulating ring (20; 120; 220) in such a way that part of a radial outside face of the metal ring (18; 118; 218) rests at the radial inside face of the flange part (24; 124; 224) and an end face of the metal ring (18; 118; 218) at an end face of the carrier part (22; 122; 224), whereby the reinforcing ring (16; 116; 226) forms a multiple reinforcing system in which the metal ring (18; 118; 218) and the carrier part (22; 122; 222) of the insulating ring (20; 120; 220) are separate position-wise and independent of each other, each functionally bearing at its axial height of the holding armatures (28; 128; 228) the force resulting from the effect of the centrifugal force of the copper segments (26; 126; 226), whereby a first part (1) of the radial outer surface of the holding armature (28; 128; 228) presses through an intermediate layer (30; 130; 230) of the moulding material (12; 112; 212) resistant to compression at high temperatures onto the metal ring (18; 118; 218), characterised in that the carrier part (22; 12; 222) of the insulating ring (20; 120; 220) has a smaller inside diameter than the metal ring (18; 118; 218) and that a second part (b) adjoining in axial direction the first part (a) of the radial outside surface of the holding armature (28; 128; 228) carries the carrier part (22; 122; 222) of the insulating ring (20; 120; 220) on its own.
10. Method of producing a commutator (10; 110; 210) according to Claim 9, characterised in that the metal ring (18; 118; 218) is punched from a metal plate or parted off from a metal tube.
11. Method of producing a commutator (10; 110) according to Claim 9 or 10, characterised in that the insulating ring is a fibreglass ring (20; 120; 220) made by appropriately winding glass fibres with the addition of synthetic resin or by parting off from a fibreglass tube.
12. Method of producing a commutator (210) according to one of the Claims 9 to 11, whereby the commutator is a flat commutator (210), characterised in that the metal ring (218) is annular and has a coaxial groove into which the part (224) bearing on the metal ring (218) can engage on compression, the groove (234) being stamped into the metal ring (218) in such a way that an annular continuation (236) is formed on the opposite side of the metal ring (218).
13. Method of producing a commutator (212) according to Claim 12, characterised in that the insulating ring (220) is given a stepped shape on compression with a carrier part (222) and at a flange part (224), whereby the flange part (224) engages into the groove (234) of the metal ring (218) with an offset and the space between the inside face of the metal ring (218) and the legs (128; 228) of the copper segments (226) adjoining the axis of rotation (214) are subsequently filled with moulding material (212) which is part of the insulating body of the flat commutator (210).
14. Method of producing a commutator (10; 110; 210) according to one of the Claims 9 to 13, characterised in that, after inserting the reinforcing ring (16, 116, 216), only the carrier part (22; 122; 222) of the insulating ring (20; 120; 220) on the part of the holding armatures (28; 128; 228) radially pointing to the outside is independently preloaded by the metal ring (18; 118; 218).

Images