EP1232543B1 - Plane commutator, method for producing the same and conductor blank for using to produce the same - Google Patents

Abstract

A flat commutator for an electrical machine comprises a support body (1) made of an insulating molding compound, a plurality of conductor segments (3) and an equal number of carbon segments (4), which are disposed at the ends and are connected in electrically conductive relationship to the conductor segments (3). Each of the conductor segments (3) is provided with a thick-walled terminal region (6) disposed on the periphery of the support body (1), a contact region (7), which is also thick-walled, disposed between the support body (1) and the associated carbon segment (4), and a thin-walled transition region (8) disposed between the terminal region (6) and the contact region (7).

Description

The present invention relates to a flat commutator for an electrical machine, comprising one of insulating Preßstoff manufactured carrier body, a Plurality of conductor segments and an equally large one Number of carbon segments, which are arranged on the front side and electrically conductive with the conductor segments are connected, wherein the conductor segments each one arranged on the circumference of the carrier body, thick-walled Connection area, one between the support body and arranged the associated carbon segment, also thick-walled contact area and a between the terminal area and the contact area having arranged thin-walled transition region. Furthermore, the present invention relates to a Method for producing such a planar commutator and a conductor blank for use in the Production of such a planar commutator.

Plankommutatoren with an insulating material manufactured carrier body, a plurality of conductor segments and an equally large number of carbon segments, which are arranged on the front and with the conductor segments are electrically connected, count in many different versions to the stand of the technique. It should be noted in this context For example, to US 5175463 A1, DE 98007045 U1, DE 19752626 A1, US 5255426 A1, DE 19652840 A1, WO 97/03486, DE 19601863 A1, DE 4028420 A1, EP 0667657 A1, US Pat. No. 5,442,849 A1, WO 92/01321, DE 19713936 A1, US Pat. No. 5,637,944 A1, DE 9211488 U1 and DE 19713936 A1. Further relevant prior art form the US Pat. No. 5,629,576 A1, DE 19903921 A1 and EP 0935331 A1. From Two of these publications disclose a plan commutator with the further features specified above. So is the Plankommutator after the DE 4028420 A1 (corresponding to GB 2247994 A) between the Terminal areas and the contact areas of the conductor segments each provided a constriction; the corresponding reduction of the cross section is used seen during the manufacture of the conductor blank the defined setting up of the connection areas from the initially flat starting material to favor. In the known from DE 9211488 U1 Plankommutator is on the outer surface of the conductor segments a stage provided, which in a corresponding Reduction of the material cross section between the Connection areas and the contact areas results. This stage is later filled up with molding material, so that the carbon segments of the finished flat commutator from a circumferentially closed Preßstoffring are bordered.

The large number of property rights, dealing with plan commutators deal with carbon tread, proves the great need for practicable commutators This type, in particular for driving Fuel pumps are used in motor vehicles. At the same time, the large number of publications can be infer that it There are a variety of problem areas that have not been so far were solved satisfactorily.

This is partly due to the fact that at known generic plan commutators different Requirements z.T. compete with each other; For this In particular, the objectives of small dimensions, low production costs and long service life of Commutator. A particularly serious of the above addressed competition exists between the reduction of the dimensions and the increase of the Life of the flat commutator; because the wires of the Rotor windings are generally on the conductor segments welded, what with too small dimensions of the flat commander easily to one due to overheating caused damage to the electrically conductive Connections of the conductor segments with the carbon segments leads, in turn, a reduced life of the Plankommutators entails. Indeed It is so that the known, in the above Publications described plan commutators, as far as they are produced by soldering electrically conductive connection between the carbon segments and the conductor segments go out in the Practice as a result of the above problem and the resulting unsatisfactory service life not be used. This is the background for example, for the proposals to connect the Carbon segments with the conductor segments to use high-temperature resistant brazing material (cf. EP 0935331 A1) or the contact points between conductor segments and carbon segments relatively far to be arranged away from the terminals of the rotor winding (see DE 19903921 A1). However, the first is Place mentioned proposal with additional costs and the second proposal with larger Dimensions of the commutator connected.

The present invention aims to provide a plan commutator to provide the type specified, which can be produced comparatively inexpensively and at the same time despite relatively small dimensions one has a long service life. Furthermore, it is the task of the present invention, a method for Production of such a plan commutator and especially expedient in such a production process to create used intermediates.

The above mentioned problem is solved according to the present invention characterized in that in a Plankommutator of the type mentioned in the evenly thin transition areas of Conductor segments in a substantially radial extent oriented to the commutator axis and away from the Carbon segments to the contact areas of Conductor segments are connected, wherein between the Transition regions of the conductor segments on the one hand and the carbon segments, on the other hand, one each Preßstoffschicht consists. Essential for the plan commutator according to the invention is thus a Combination of several features: The conductor segments are not with one everywhere more or less the same Wall thickness executed; rather, they differ Wall thicknesses of different areas of the conductor segments significantly different from each other, namely between the Terminal area, the connection of the rotor winding serves, and the contact area through which the electrical conductive connection of the conductor segment with the associated Carbon segment is prepared comparatively thin-walled transition region exists. These evenly thin-walled executed Transition areas of the conductor segments are in essentially in radial extent to Commutator axis oriented and away from the Carbon segments to the contact areas of Conductor segments connected. The way this way first between the carbon segments and the Transition areas of the conductor segments existing gap is filled with a Preßstoffschicht.

In plan commutators according to the present invention is thus the - perpendicular to the heat flow direction certain - wall thickness of the transition area lower as the wall thickness measured in the radial direction the connection area and the - in the axial direction measured wall thickness of the contact area of the relevant conductor segment, wherein the connection area also in the axial and in the circumferential direction comparatively large dimensions (see below). Such a design of the conductor segments leads in particular, that even with extremely compact, the smallest dimensioned plan commutators the Welding the winding wires to the terminal areas the conductor segments do not cause an overheating Damage to the electrically conductive connections of the Conductor segments with the carbon segments leads. Because the thick-walled connection areas of the conductor segments form a first because of their high heat capacity Heat sink for the welding process developed Warmth. The thin-walled transitional area of Terminal area to the contact area forms in contrast because of it - normal to heat flow aligned - small cross-sectional area for the heat conduction of Connection area to the contact area of the conductor segment a considerable resistance. And the thick-walled one Contact area again forms a pronounced heat sink for the (reduced anyway) through the transition area passed heat energy. The result is that the contact area of the conductor segments when welding the wires of the rotor winding to the Conductor segments by no means to such an extent heated as known in the art is. In application of the present invention when using conventional welding methods Reductions in the connection of the conductor segments with the carbon segments occurring maximum temperatures around 50 ° C or even more known Plankommutatoren generic type to reach. As a consequence, the danger is that the electrically conductive compounds of the carbon segments with the conductor segments when welding the Rotor winding to be damaged at the plan commutator, significantly reduced. In application of the present Invention let the carbon segments even by soldering permanently with the conductor segments connect electrically, as at the contact point occurring temperatures reliably below the Softening point for soft solder lie. this applies even for extremely compact flat commutators. In this Context also has an advantageous effect that at Application of the present invention no need exists more, the electrically conductive connection the carbon segments with the conductor segments in one the greatest possible distance to the connection areas of the To bring conductor segments, which so far many times too radially inner, relatively small contact surfaces between the carbon segments and the Conductor segments has led. Rather, can be in Application of the present invention quite large format Contact surfaces between the conductor segments and the carbon segments realize what's up favorable to the life of the corresponding Connection.

The inventively provided, explained above thin-walled transition area between the connection area and the contact area of each conductor segment By the way, this does not only affect its thermal resistance (see above) as advantageous. Another highlight is the by the evenly thin-walled, substantially radially to Commutator axis oriented Transition areas - during the manufacture of the Plankommutators - Provided resilient axial compliance of Contact areas of the conductor segments, if so, like this is further provided according to the invention, the Carbon ring to the connection areas and the Transition areas of the conductor blank one - later filled with pressed material - adheres to distance. Because these limited axial resilience when out of Conductor blank and carbon ring formed Composite part for spraying the carrier body in a Injection mold is inserted when closing the Injection tool exerted on the carbon ring washer Force. Due to the elasticity of the transition areas and the thereby possible axial compression of the Contact areas when closing the injection mold is the pressure exerted on the carbon ring washer controllable. The main closing force is in Compressive stresses in the connection areas and the These possibly connecting bridge parts and connecting webs (see below) implemented; even such Closing forces that lead to deformation of the conductor blank in the axial direction by 1 to 4% are without damaging the carbon ring realizable. The commutator can do this way regardless of tolerances, in the economic Production of the carbon ring and the Conductor blanks are unavoidable in the injection mold be made exactly to its nominal size. A subsequent end-side rework is unnecessary, whereby a cost saving is possible. The effective limitation of the carbon ring acting pressure reduces the risk of Damage to the carbon ring during the Production of the plan commutator and contributes to this Way to a reduction of the committee. The The present invention also allows for the Production of the carbon ring disc comparatively inexpensive material is used, such as For example, relatively pressure sensitive, brittle and injury-sensitive plastic bound Carbon.

The above-described axial compression of the contact areas of the conductor blank together with the at this adjacent carbon ring against the Connecting areas of the conductor blank becomes special favors if the transitional areas are a minimum extension which is about 5%, preferably about 8 is up to 10% of the radius of the finished plan commutator, what with small commutators common sizes Diameter about 20 mm) of a radial minimum extent the transitional areas of at least 1 mm corresponds.

According to the invention, as stated above, provided that the transition areas of Conductor segments away from the carbon segments the contact areas of the conductor segments connected are. In this way arises between the Transition areas and possibly the connection areas of Conductor segments on the one hand and the carbon segments on the other hand in each case a gap, which later with a Preßstoffschicht is filled. The of the contact surface the contact areas of the conductor segments removed Connections of the transition areas affect a significantly reduced heat transfer from the Transition regions of the conductor segments on the carbon segments out. The effect of the Preßstoffschicht Moreover, there is an improved protection of the electrically conductive connections between the contact areas the conductor segments and the carbon segments towards aggressive media.

With regard to the inventively provided, explained above different wall thicknesses the conductor segments in their different areas proves the preparation of a conductor blank, such as he for the production of the plan commutator according to the invention is used, by a combined Extrusion and stamping process as particularly favorable. First, will produced by extruding a cup-shaped body, already characterized by thick-walled connection areas, thin-walled transition areas and turn thick-walled contact areas is characterized, wherein the Contact areas and possibly also the transition areas still with each other forming a closed Ringes are connected. By punching is then the Segmented bottom of the main body.

The ideal dimensions of each area of the Conductor segments, in particular the different wall thicknesses and their relation to each other, depend on different influencing factors. However, it shows already in the case that the wall thickness of the transition areas the conductor segments less than 80% of the wall thickness the contact areas is a significant Improving the life of the electrically conductive Connections between the carbon segments and the Conductor segments over the prior art. Particularly preferred is the wall thickness difference greater by the wall thickness of the transition areas of the Conductor segments less than 60% of the wall thickness of Contact areas is. This increases, provided the Transition areas away from the carbon segments connected to the contact areas of the conductor segments are the distance of the transition regions of the conductor segments to the carbon segments. For sizing the contact areas has moreover than Advantageously, when the wall thickness of the Contact areas at least 0.4 times the value of Extension of the contact areas in the circumferential direction is.

The terminal areas are otherwise preferred in FIG Circumferential and dimensioned so large in the axial direction, that a double electrode on both sides of the connection hook comfortably fits. In this sense extend the connection areas preferably over at least 65%, more preferably over at least 80% of the circumference of the Plankommutators. Such a big one Dimensioning of the connection areas affects the rest low on the heat capacity of the terminal areas from and thus favors the inventive Thermal behavior.

It has already been stated above that when used the present invention is not necessary the electrically conductive connections between the Carbon segments and the conductor segments relatively small, radially inner contact areas to concentrate. In the sense of maximizing the for the electrically conductive connections available standing surface is a preferred development the present invention in that the Contact areas of the conductor segments over the entire surface with the End faces of the carbon segments in contact stand. The contact surfaces on the front surfaces of the Carbon segments can thereby circulating closed or open, frame-like surveys, their contour to the contour of the contact areas of Conductor segments is adapted and the adjustment of Carbon ring disk and conductor blank to each other during the manufacture of the plan commutator, be completely or partially surrounded. Also this feature is again related to the above mentioned manufacturing method of the conductor blank by combined extrusion and punching. Because thick-walled contact areas leading to the full-surface Contact with the carbon segments within those frame-like elevations are suitable, can be do not manufacture if the conductor blank, like this previously practiced by deep drawing a sheet is formed.

Is on the above-described frame-like Surveys omitted, so can the contact surfaces over the entire associated end faces of the Carbon segments extend so that the carbon segments fully electrically conductive with the Contact areas of the conductor segments are connected.

In the area of the aforementioned contact surfaces of Carbon segments may be particularly preferred between the contact areas of the conductor segments and the carbon segments an electrically conductive contact material be included. This can, for example, a Be soft solder (see above). It can, however, for example also consist of grains, powder and / or Platelets of a metal, for example of silver. Because in particularly preferred developments of Plankommutators according to the invention is what further will be discussed in more detail below, one mechanically bearing connection of the contact areas with the carbon segments by solder or the like not necessary if the carbon segments at their radially inner and outer peripheral surfaces fixed in the embedded in molded plastic carrier body are embedded.

In the sense set forth above, the carbon segments are particularly preferably at its radial outer peripheral surfaces each of a through the Carrier body formed Preßstoffmantel covered, between outer peripheral surfaces of the carbon segments and the Preßstoffmänteln particularly preferred each form-fitting connections exist. The latter can be done in any known way, in particular as grading, toothing, sawtooth toothing or the like. be executed. Particularly preferred is a Corrugation.

A particularly preferred embodiment of the invention Plankommutators is characterized in that the terminal areas of the conductor segments are in Have circumferential direction extending axial groove, in which engages a rib of the Preßstoffmantels. This results in a toothing of the Preßstoffmantels with the associated conductor segment, which is particularly positive for the stability of the commutator effect. The groove can in particular initially as Rectangular groove be executed when punching the Soil of the first produced by extrusion Level of the conductor blank is impressed in these. at Close an injection mold into which the Composite part by joining the conductor blank originated with the carbon ring (see below), for molding the carrier body made of molded material is inserted, deforms in a suitable design the groove whose outer boundary under the closing forces radially inward, so that the groove undercut is; this leads to a particularly firm hold the Preßstoffrippe in the groove.

The terminal areas of the conductor segments are particularly preferably radially over the outer peripheral surfaces the above-explained Preßstoffmäntel about. This feature can be seen in connection with the explained below particularly preferred Manufacturing process and in its implementation used conductor blank.

Another preferred embodiment of the invention Plankommutators is characterized in that the core of the carrier body, the radially inner peripheral surfaces the carbon segments to form positive Connections covered. In particular in Compound with the above-explained, the outer Covering peripheral surfaces of the carbon segments Preßstoffmänteln results in a sufficiently strong mechanical connection of the carbon segments with the Carrier body, so that on a mechanically bearing Connection of the contact areas of the conductor segments with can be dispensed with the carbon segments (see above).

Yet another preferred embodiment of Invention is characterized in that the Terminal areas contact lugs are arranged, the beveled end. Such, the outer Peripheral surface of the associated connection area facing bevel leads to a reduction of Contact surface between the to the terminal areas of the Conductor segments hinangebogene contact flags and the Terminal areas of the conductor segments near the connection to the carbon segments. This is again favorable in terms of the lowest possible transmission when welding the wires of the rotor winding Heat generated on the conductor segments on the electrically conductive connections between the Terminal regions of the conductor segments and the carbon segments.

Furthermore, it is advantageous if the carbon segments at their outer, the conductor segments facing circumferential edges are executed stepped. On This way, in this area arises an annular Reinforcement made of pressed material, which makes a particularly good Protection of the relevant edge of the carbon disc is effected.

The expediently for producing the above commutator used conductor blank comprises a plurality from around an axis arranged conductor segments, in front each two connected to each other via a bridge part are, wherein the conductor segments each one on Outer circumference of the conductor blank arranged thick-walled Connection area, a frontally arranged, ebenfall thick-walled contact area and one between the terminal area and the contact area arranged dünnwan have the transition region and the even thin-walled transition areas of the conductor segments in essentially oriented in the radial direction to the axis and away from the end faces of the contact areas these are connected. Particularly preferred are the bridge parts between the terminal areas of two arranged adjacent conductor segments, in such a way that the bridge parts and the terminal portions of the conductor segments have the same axial extent and along their entire axial extent via connecting webs connected to each other. Described by the above bene arrangement and design of the bridge parts arise on both end faces of the tubular conductor blank in in each case a plane perpendicular to the axis lying, annular closed surfaces. These are suitable in an excellent way as sealing surfaces for the both halves of an injection molding tool when spraying the carrier body made of molding material is used. The through the connection areas, the bridge parts and the connecting webs circumferentially closed tubular conductor blank thus concludes in cooperation with the two Halves of the injection mold to be filled with molding material Space tight.

The tubular shape of the conductor blank allows in rest, that the two halves of the injection mold in the region of their respective sealing surface with the Exactly opposite the conductor blank. This is special favorable in view of the high closing forces. Because These are of the conductor blank without unduly high Deformation recorded. The closing forces are calling in the tubular conductor blank substantially alone Compressive stresses.

The above-mentioned annular support of both halves of the injection tool on the two opposite annular sealing surfaces of the conductor blank entails that the outer Peripheral surface of the Preßstoffmäntel, if provided are, a smaller distance to the commutator axis have as the outer peripheral surfaces of Connection areas of the conductor segments. Accordingly are the connection areas of the conductor segments below Forming a step radially over the outer peripheral surfaces the Preßstoffmäntel over.

The wall thickness of the above-explained connecting webs is particularly preferably considerably less than the wall thickness of the bridge parts. This is enough to during injection of the carrier body of molding material withstand existing pressure. The small wall thickness the connecting webs facilitates the later, after the Shaping the carrier body taking place the Bridge parts. In this context, it turns out as particularly advantageous when the distance of the radial inner peripheral surfaces of the bridge parts to the commutator axis at least equal, more preferably even is slightly larger than the distance of the radial outer peripheral surfaces of the terminal regions of the conductor segments to the commutator axis. Because this makes it possible Shearing or bumping the bridge parts after molding of the carrier body by an axially acting punch. An elaborate twisting the outer peripheral surface of the Plankommutators to remove the bridge parts is not required in this case.

In the context of the production of the invention Plan commutator is particularly preferably a carbon ring for use. This will be with the Ladder blank joined together, with particular preference the contact areas of the conductor segments on the front side the carbon ring on contact surfaces abutment, which of circumferentially closed or open frame-like elevations in whole or in part are enclosed, whose inner contour to the outer contour the contact areas of the conductor segments corresponds (see above). The unit of ladder blank and Carbon ring disk is then used to form the Carrier body made of molded material in an injection mold inserted. After the carrier body has been formed, is the carbon ring disc by separating cuts in divided into individual carbon segments.

The above-described frame-like elevations of Carbon ring discs are completely in molding material embedded or enclosed by this. This ensures especially with circumferentially closed Execution of the frame-like surveys, not only optimum protection of the contact surfaces between the Carbon segments and the conductor segments against aggressive media. It also leads to an independent Fixation of the carbon segments in the carrier body in the circumferential direction and contributes to a fixation of Carbon segments in the carrier body in radial Direction at.

Should the electrically conductive connections of the Carbon segments with the contact areas of Conductor segments are made by soldering, so is the carbon ring before at least to the metallize later contact surfaces. Suitable for this purpose as such known galvanic process. In This case is expediently the carbon ring metallized on its entire face; and the frame-like elevations are preferably open executed. According to a particular aspect of Present invention, the metallization takes place however, preferably by high-pressure compression of Metal particles, in particular of - if necessary silvered - Cu or Ag powder, in the later contact surfaces of the Carbon ring disc followed by sintering. This form of metallization of carbon ring limited preferably to the later Contact surfaces, which in turn preferred by circumscribed closed frame-like surveys bounded are.

The flat commutator according to the invention has according to a preferred development via a centric bore, which has a widened area extending from the tread in the axial direction across the depth between the carbon segments Dividing cuts extends. Particular preference is given the widened area is conical. This reduces the risk of short-circuiting Coal and / or metal dust over the shaft, on the the commutator is attached. By the conicity Nevertheless, the stiffness of the commutator is largely maintained.

From the above explanations of the present Invention is apparent that this is a Plankommutator provides with previously unknown properties. In particular, the invention is characterized Plankommutator with low production costs by a justified in particular by the high stability superior quality, with particularly low Dimensions are possible. In addition, the overmolding of the Carbon segments easily possible; and the Injection tool can be very simple. In addition, the conductor blank can be inside and outside have a continuous contour so that it is in insert a die.

Fig. 1

einen Axialschnitt durch einen gemäß der vorliegenden Erfindung aufgebauten Plankommutator,

Fig. 2

den Plankommutator gemäß Fig. 1 in Seitenansicht,

Fig. 3

den zur Herstellung des Plankommutators gemäß den Fig. 1 und 2 verwendeten Leiterrohling im Axialschnitt,

Fig. 4

den Leiterrohling gemäß Fig. 3 in Draufsicht von oben (Pfeil IV in Fig. 3),

Fig. 5

den Leiterrohling gemäß den Fig. 3 und 4 in Draufsicht von unten (Pfeil V in Fig. 3),

Fig. 6

die zur Herstellung des Plankommutators gemäß den Fig. 1 und 2 verwendete Kohlenstoffringscheibe in perspektivischer Ansicht,

Fig. 7

eine zweite bevorzugte Ausführungsform der zur Herstellung eines erfindungsgemäßen Plankommutators verwendeten Kohlenstoffringscheibe,

Fig. 8

einen Axialschnitt durch eine weitere bevorzugte Ausführungsform eines gemäß der vorliegenden Erfindung aufgebauten Plankommutators,

Fig. 9

eine Abwandlung des in Fig. 8 veranschaulichten Plankommutators im Axialschnitt,

Fig. 10

eine weitere Abwandlung des in Fig. 8 veranschaulichten Plankommutators im Axialschnitt und

Fig. 11

das axiale Einfedern des Leiterrohlings während der Herstellung des Plankommutators etwa entsprechend Fig. 10.

In the following, the present invention will be explained in more detail with reference to a preferred embodiment illustrated in the drawing. It shows

Fig. 1

an axial section through a constructed according to the present invention Plankommutator,

Fig. 2

the plan commutator of FIG. 1 in side view,

Fig. 3

the conductor blank used for the production of the planar commutator according to FIGS. 1 and 2 in axial section,

Fig. 4

the conductor blank according to FIG. 3 in plan view from above (arrow IV in FIG. 3),

Fig. 5

the conductor blank according to FIGS. 3 and 4 in plan view from below (arrow V in FIG. 3),

Fig. 6

1 and 2 used in the manufacture of the planar commutator according to FIGS. 1 and 2 in a perspective view,

Fig. 7

A second preferred embodiment of the carbon ring disk used for producing a flat commutator according to the invention,

Fig. 8

an axial section through a further preferred embodiment of a constructed according to the present invention Plankommutators,

Fig. 9

a modification of the plan commutator illustrated in Fig. 8 in axial section,

Fig. 10

a further modification of the illustrated in Fig. 8 Plankommutators in axial section and

Fig. 11

the axial compression of the conductor blank during the production of the planar commutator approximately corresponding to FIG. 10.

The plan commutator according to FIGS. 1 and 2 comprises a made of insulating molding material carrier body 1, eight evenly distributed around the axis 2 arranged around Conductor segments 3 and eight carbon segments 4, each of which each with a conductor segment 3 is electrically connected. The carrier body 1 has a central bore 5. To this extent corresponds to the plan commutator according to FIGS. 1 and 2 the commonly used prior art, so that the basic structure is not explained in more detail needs to be.

The existing copper conductor segments 3 are how is explained in detail below, from the in the Fig. 3 to 5 emerged conductor blank emerged. They comprise three zones, namely the connection area 6, the contact area 7 and the two connecting the aforementioned areas Transition area 8. At each of the contact areas 6 is arranged a contact lug 9. This serves the electrically conductive connection of a winding wire 10 with the relevant conductor segment 3. The contact lugs 9 have a bevel at the end (see FIG 11, and on that surface, which in the finished plan commutator facing radially inward and the associated connection area 6 of the relevant conductor segment 3 is adjacent.

For better anchoring of the conductor segments 3 in the Carrier body 1 is of the terminal areas 6 each Conductor segment 3 obliquely inwardly a retaining claw 12th in front. For the same purpose are at the radially inner Ends of the contact regions 7 of the conductor segments 3 anchor parts 13 provided, which is substantially parallel to the axis stand out from the contact areas. The anchor parts 13 have notches on their radially outer peripheral surface 14 on.

Of particular importance to the present invention is the dimensioning of the conductor segments 3 in their different sections. While the - in radial Direction measured - thickness of the terminal areas 6 and the - measured in the axial direction - thickness of Contact areas 7 is large, are the transition areas 8 executed particularly thin-walled. The transition areas 8 are removed from the carbon segments 4 connected to the contact areas 7, so that no There is contact between the connection areas 6 and the transition regions 8 of the conductor segments 3 on the one hand and the carbon segments 4, on the other hand.

The contact areas 7 of the conductor segments 3 are located full contact surfaces 15 at which frontally are arranged on the carbon segments 4. in the Area of the contact surfaces 15 is between the contact areas 7 of the conductor segments 3 and the carbon segments 4 is an electrically conductive contact material 16 added. The contact surfaces 15 are of circumferential closed frame-like elevations 27 (see Fig. 6) surrounded, which from the end face 28 of the carbon segments 4 project. The inner contour of the frame-like Elevations 27 of the carbon segments 4 is so on the contour of the contact regions 7 of the conductor segments. 3 sealing adapted that during the molding of the carrier body. 1 no molding material can reach the contact surfaces 15.

The carbon segments 4 are at their radially outer Peripheral surfaces each of a Preßstoffmantel 17 of the Carrier body 1 covered. It consists of a stepped execution of the outer peripheral surface of Carbon segments 4 a positive connection to the respective Preßstoffmantel 17. The terminal areas 6 of the conductor segments 3 are radially slightly above the outer peripheral surfaces of the Preßstoffmäntel 17 on, whereby on the outer circumference of the Plankommutators a step 18 arises.

The core of the carrier body 1 also covers the radial inner peripheral surfaces of the carbon segments 4. Also here exists as a result of a stepped execution of radially inner circumferential surfaces of the carbon segments 4 a positive connection. The positive locking Compounds of the carbon segments 4 with the carrier body 1 in the region of its radially inner and outer Circumferential surfaces ensures a permanent hold the Carbon segments in the carrier body 1. Also in The circumferential direction engage the carbon segments 4 positively in the carrier body 1, via the frame-like elevations 27.

In Fig. 1, finally, the Preßstoffschicht can be seen 19, between the terminal areas 6 and the transition regions 8 of the conductor segments 3 and the associated carbon segments 4 consists. The fat that Preßstoffschicht 19 depends in particular on the Ratio of the thicknesses of the transition regions 8 and Contact areas 7 of the conductor segments 3 to each other.

The Radial cuts 20, with which under the Production of the plan commutator one first integral carbon ring washer (see Figures 6 and 7) divided into the individual carbon segments 4 was, are also shown.

Fig. 2 illustrates the particularly large format outer peripheral surface of the terminal portions 6 of the conductor segments 3. On both sides of the contact lugs 9 are two comparatively large zones for contact with Welding electrodes during the welding of the Winding wire 10 with the relevant conductor segment to disposal.

Figs. 3 to 5 illustrate that for the production of the plan commutator according to FIGS. 1 and 2 used Ladder blank in section, in plan view from above and in Top view from below. Many details of the ladder blank arise directly from the above explanation Figures 1 and 2. in this respect reference is made to the above statements. An important feature the ladder blank is complete at the circumference closed tubular shape. Between every two Terminal areas 6 is a bridge part 21. Die Bridge parts 21 and the terminal portions 6 of the conductor segments 3 have the same axial extent and are over along their entire axial extent over Connecting webs 22 connected to each other. hereby arise on both ends of the conductor blank closed annular surfaces 23 and 24, which are alternately from the end faces of the terminal regions 6 the conductor segments 3 and the bridge parts 21 together. This is, as explained above, of particular advantage for a tight conclusion of the Pressing tool on the conductor blank, with respect to on the extremely high injection pressures required high Closing forces do not cause harmful deformation of the Leading conductor blanks.

The connecting webs 22 are - by appropriate Dimensioning of grooves 23 - extremely thin-walled. This allows the bridge parts 21, after the carrier body 1 has been injection molded by pushing in the axial direction in a single operation can be removed. For this purpose, it is otherwise provided that the distance 24 of the radially inner peripheral surfaces the bridge parts 21 to the commutator axis 2 not smaller but equal, more preferably minimal greater than the distance 25 of the radially outer peripheral surfaces the terminal regions 6 of the conductor segments. 3 to the commutator axis 2.

In Fig. 6, which for the production of the planar commutator As shown in FIGS. 1 and 2 used carbon ring disk illustrates, the shape of the front side provided frame-like elevations 27, which surround the contact surfaces 15, to recognize well. in the Comparison with Fig. 5 is also seen that the inner contour the frame-like elevations 27 on the outer contour the contact areas 7 of the conductor segments 3 matched is.

It can be seen in Fig. 6 of the further profiled outer and inner peripheral surface of the carbon ring disk, that of a positive connection of later carbon segments 4 with the molding material of Carrier body 1 in the region of the core or the respective Preßstoffmantels 17 is used.

The contact surfaces 15 are by pressing metal powder into the surface before sintering metallized.

The illustrated in Fig. 7 carbon ring disk differs from that of FIG. 6 in that that the frame-like elevations 27 not circulating closed but rather open. You surrounded the contact surfaces 15 thus only partially; corresponding surround them in the finished plan commutator also the Contact areas 7 of the conductor segments 3 only partially. For a reliable adjustment of the conductor blank and the carbon ring to each other during the Making the plan commutator is sufficient.

The entire face of the carbon ring is metallized by electroplating.

FIG. 8 illustrates another according to FIG Plane commutator constructed in accordance with the present invention characterized by the features indicated below of the Plankommutator according to FIG. 1 differentiates:

A first difference of the planar commutator according to FIG. 8 relative to that of FIG. 1 relates to Anchoring the Preßstoffmantels 17 of the carrier body. 1 with the terminal regions 6 of the conductor segments 3 via a gearing 31. This is formed by a in the circumferential direction extending axial groove 32 in the Terminal areas 6 of the conductor segments and a in this groove engaging Preßstoffrippe 33. Recognizable is the undercut of the groove 32, which arises by upsetting the outer annular boundary of Groove when closing the injection mold, in which the Carrier body 1 has been formed.

Otherwise, a comparison of FIGS. 8 and 1 with each other, that the Plankommutator shown in FIG. 8 via a differently executed centric bore 5 has. For here the hole 5 has a conical extension 34, which via a step 35 to the cylindrical Section 36 of the hole connects. The cuts 20, by means of which the carbon ring disc in the individual carbon segments 4 is divided, open in the widened region 34 of the central bore 5th

The carbon segments 4 are only in the range of surrounded by the frame-like elevations 27 Contact surfaces 15 metallized, by Pressing metal powder into the surface of the Carbon ring disk before sintering. The carbon segments are through with the conductor segments Soft soldering electrically connected.

Otherwise, the illustrated in Fig. 8 corresponds Plankommutator that of FIG. 1, so that the Avoid repetition on the corresponding References.

Regarding its basic design features corresponds to the plan commutator shown in Fig. 9 the plan commutator of FIG. 8. To avoid Repetitions will therefore be related to the basic structure of the illustrated in Fig. 9 Plankommutators to the comments on Fig. 8 referred to below and only to the differences received. For one thing, the frame-like Elevations 27 ', which surround the contact surfaces 15, a semicircular cross section. This facilitates not only the joining of the conductor blank with the Carbon ring disk in the production of the Commutator. Another advantage of this form of frame-like elevations 27 'is that Preßstoffmasse in the wedge-shaped areas 37 between the peripheral surfaces of the contact regions 7 of the conductor segments 3 and the adjacent frame-like Elevations 27 'penetrates. This favors a solid Connection of the carbon segments 4 at the contact areas 7 of the conductor segments 3. Furthermore, it is favorable that the frame-like elevations 27 'complete with the molding compound of the carrier body are covered.

Another difference of the plan commutator according to Fig. 9 compared to that illustrated in Fig. 8 Plankommutator consists in an enlarged radial Extension of the transition regions 8 of the conductor segments 3. With an outside diameter of the finished flat commutator of about 20 mm, the radial extent of Transition areas 8 about 1 mm. The transition areas are aligned radially; their - in the axial Direction certain - wall thickness is about 0.7 mm, wherein the - determined in the radial direction - wall thickness the connection areas 6 about 1.2 mm and - in the axial Direction specific - wall thickness of the contact areas 7 about 1.4 mm. The cross section over which everyone Transition region 8 to the associated contact area. 7 is connected, is due to the level 38 only about 0.5 mm high, resulting in a reduction of the Heat flow from the terminal areas 6 over the Transition regions 8 to the contact areas 7 effects.

Finally, it can be seen that, unlike that for the Plankommutator according to FIG. 8, in the terminal areas 6 of the conductor segments 3 is not an axial groove is introduced. However, the transition areas 8 to form a level 39 against the End edges 40 of the terminal portions 6 of the conductor segments 3 offset. Due to the wall thickness of the connection areas 6 and the radial extent of the transition areas 8 of the conductor segments 3 it follows that between the radial outer surface of the carbon segments 4 on the one hand and the radial outer surface of the Contact areas 7 of the conductor segments 3 on the other a considerable distance (in the present case approx. 1.8 mm) exists. This results radially outside the frame-like Elevations 27 'a comparatively large End face 28 'of the carbon segments 4, via which these are in communication with the carrier body 1. Overall, about the end faces 28 'and the Elevations 27 'each areas that about 50 to 70% the treads of the carbon segments 4 correspond, with the molding material of the carrier body 1 in conjunction.

The plan commutator according to FIG. 10 corresponds with regard to its essential design features to those according to Fig. 9. This also applies to the shape of the frame-like Elevations 27 ', the size of the contact surfaces 15th and the wall thicknesses of the terminal portions 6, the Transition areas 8 and the contact areas 7 of Lead segments 3. However, close the here Transition areas 8 of the conductor segments 3 flush to the End faces 40 of the terminal portions 6, so that the Steps 38 and 39 illustrated in FIG. 9 do not consist.

Fig. 11 illustrates the relationships in the Production of the plan commutator shown in FIG. 10, namely, when inserted in an injection mold, from a conductor blank and one with this bonded carbon ring disk existing Composite part. The upper half 41 of the injection mold abuts against a sealing surface 42, which is formed through the upper end faces of the contact regions 6, the bridge parts 21 and the connecting webs 22 (see. Fig. 4). The lower half 43 of the injection mold is located in a corresponding manner to a sealing surface 44, which is formed by the lower end face of Terminal areas 6, the bridge parts 21 and the Connecting webs 22. Fig. 11 shows that possible Thickness tolerances of carbon ring can be compensated by axial compression (Arrow A) of the contact areas 7 of the conductor blank opposite the terminal portions 6 under deformation of the Transition areas 8. Thickness tolerances of the carbon ring disk Thus, do not affect the finished size of the finished plan commutator. The dimensions of the finished Plankommutators thus determine regardless of possible dimensional deviations of the carbon ring from its setpoint exclusively by the injection mold. As a result, the finished Plankommutator even without costly frontal Postprocessing exactly its nominal dimensions.

Claims (35)

1. Planar-type commutator for an electrical machine, comprising a carrier body (1) made from insulating compression moulding compound, a large number of conductor segments (3) and an equally large number of carbon segments (4), which are arranged on the end face and are electrically-conductively connected with the conductor segments (3), with the conductor segments (3) each displaying a thick-walled termination zone (6) arranged on the perimeter of the carrier body (1), an equally thick-walled contact zone (7) arranged between the carrier body (1) and the reference carbon segment (4) and a thin-walled cross-over area (8) arranged between the termination zone (6) and the contact zone (7),
   characterised in that
   the uniformly thin-walled cross-over areas (8) of the conductor segments (3) are oriented in what is essentially a radial extension of the commutator axis (2) and are connected to the contact zones (7) of the conductor segments (3) at a distance from the carbon segments (4), and there is a layer of compression moulding compound (19) between the respective cross-over areas (8) of firstly, the conductor segments (3) and secondly, the carbon segments (4).
2. Planar-type commutator according to claim 1,
   characterised in that
   the wall thickness of the cross-over areas (8) of the conductor segments (3) amounts to less than 60% of the wall thickness of the contact zones (7).
3. Planar-type commutator according to claim 1 or claim 2,
   characterised in that
   the termination zones (6) extend over at least 65%, especially advantageously over at least 80% of the perimeter of the planar-type commutator.
4. Planar-type commutator according to one of claims 1 to 3,
   characterised in that
   the layer of compression moulding compound (19) extends into the area between the termination zones (6) and the carbon segments (4).
5. Planar-type commutator according to one of claims 1 to 4,
   characterised in that
   the axial thickness of the layer of compression moulding compound (19) is at least 0.5.mm.
6. Planar-type commutator according to one of claims 1 to 5,
   characterised in that
   the radial outer surfaces of the contact zones (7) lie radially within the radial outer surfaces of the carbon segments (4) by a dimension which is between 0.5 times and 1.5 times the axial thickness of the carbon segments.
7. Planar-type commutator according to one of claims 1 to 6,
   characterised in that
   the radial inner surfaces of the contact zones (7) lie radially outside the radial inner surfaces of the carbon segments (4) by a dimension which is between 0.25 times and 1.0 times the axial thickness of the carbon segments.
8. Planar-type commutator according to one of claims 1 to 7,
   characterised in that
   there are contact tags (9) arranged on the termination zones (6) which are bevelled at the end, with the bevellings (11) turned towards the perimeter areas of the termination zones (6).
9. Planar-type commutator according to one of claims 1 to 8,
   characterised in that
   the wall thickness of the contact zones (7) of the conductor segments (3) is at least 0.4 times the value of the extension of the contact zones (7) towards the perimeter.
10. Planar-type commutator according to one of claims 1 to 9,
    characterised in that
    the contact zones (7) of the conductor segments (3) abut electrically-conductively against the entire surface against contact areas (15) which are arranged on the end face of the carbon segments (4).
11. Planar-type commutator according to claim 10,
    characterised in that
    the contact areas (15) are at least partially enclosed by frame-type elevations (27) which protrude from the end faces (28) of the carbon segments (4).
12. Planar-type commutator according to claim 11,
    characterised in that
    the area of attachment of the carbon segments (4) with the carrier body (1) in the area of the end faces (28, 28') of the carbon segments facing away from the bearing surfaces and of the elevations (27, 27') is 50 to 70% of the bearing surfaces of the carbon segments.
13. Planar-type commutator according to one of claims 1 to 12,
    characterised in that
    the extension of the cross-over areas (8) of the conductor segments (3) towards the perimeter is no greater than the extension of the contact zones (7) towards the perimeter.
14. Planar-type commutator according to one of claims 10 to 13,
    characterised in that
    an electrically-conductive contact material (16) is accommodated in the region of the contact areas (15) between the contact zones (7) of the conductor segments (3) and the carbon segments (4).
15. Planar-type commutator according to one of claims 1 to 14,
    characterised in that
    the carbon segments (4) are each covered on their radial outer perimeter areas by a compression moulding compound sheath (17) of the carrier body (1).
16. Planar-type commutator according to claim 15,
    characterised in that
    the termination zones (6) of the conductor segments (3) display an axial groove (32) extending at least partly in the direction of the perimeter, in which a rib (33) of the compression moulding compound sheath (17) engages.
17. Planar-type commutator according to claim 15 or claim 16,
    characterised in that
    the termination zones (6) of the conductor segments (3) stand proud radially above the external perimeter areas of the compression moulding compound sheath (17).
18. Planar-type commutator according to one of claims 15 to 17,
    characterised in that
    there are keyed connections between the respective outer perimeter areas of the carbon segments (4) and the compression moulding compound sheaths (17).
19. Planar-type commutator according to claim 18,
    characterised in that
    the keyed connection is in the form of an undulation (30).
20. Planar-type commutator. according to one of claims 1 to 19,
    characterised in that
    the carrier body (1) overlaps the radial inner perimeter areas of the carbon segments (4) forming keyed connections.
21. Planar-type commutator according to one of claims 1 to 20,
    characterised in that
    the carbon segments (4) are of a stepped design on their outer perimeter edges which face towards the conductor segments (3).
22. Conductor blank for use in the manufacture of a planar commutator in accordance with claim 1, comprising a large number of conductor segments (3) arranged about an axis, which each display a thick-walled termination zone (6) arranged on the perimeter of the conductor blank and an equally thick-walled contact zone (7) arranged on the end face between the termination zone (6) and the contact zone (7),
    characterised in that
    a uniformly thin-walled cross-over area (8) is arranged between the termination zone (6) and the contact zone (7) and the conductor segments (3) are connected with each other in pairs by means of a bridge part (21) and that the uniformly thin cross-over areas (8) of the conductor segments are essentially oriented in radial extension to the axis and are connected thereto at a distance from the end faces of the contact zones (7).
23. Conductor blank according to claim 22,
    characterised in that
    the bridge parts (21) are arranged between the termination zones (6) of two adjacent conductor segments (3).
24. Conductor blank according to claim 23,
    characterised in that
    the bridge parts (21) and the termination zones (6) of the conductor segments (3) display the same axial extension and are connected with each other along their entire axial extension via connecting posts (22).
25. Conductor blank according to claim 24,
    characterised in that
    the wall thickness of the connecting posts (22) is considerably less than the wall thickness of the bridge parts (21).
26. Conductor blank according to one of claims 23 to25,
    characterised in that
    the distance from the radial inner perimeter areas of the bridge parts (21) to the commutator axis (2) is the same as or slightly greater than the distance from the radial outer perimeter areas of the termination zones (6) of the conductor segments (3) to the commutator axis (2).
27. Conductor blank according to one of claims 22 to 26,
    characterised in that
    anchor parts (13) are provided on the radial inner ends of the contact zones (7) of the conductor segments (3), which are at a distance from and essentially parallel to the axis of the contact zones (7)
28. Conductor blank according to claim 27,
    characterised in that
    the anchor parts (13) display notches (14) on the radial outer perimeter areas.
29. Conductor blank according to one of claims 22 to 28,
    characterised in that
    the extension of the cross-over areas (8) of the conductor segments (3) towards the perimeter is no greater than the extension of the contact zones (7) towards the perimeter.
30. Method for the manufacture of a planar-type commutator according to claim 1, comprising the following steps:

    production of a conductor blank comprising a large number of conductor segments (3) which are connected with each other in pairs by means of a bridge part (21), and the conductor segments (3) each display a thick-walled termination zone (6) arranged on the perimeter of the conductor blank, an equally thick-walled contact zone (7) arranged on the front face and a uniformly thin-walled cross-over area (8) which essentially extends in a radial direction, arranged between the termination zone (6) and the contact zone (7);

    manufacture of a carbon ring which displays on one end face (28) a number of frame-like elevations (27) corresponding to the number of conductor segments (3) of the conductor blank;

    joining of the conductor blank to the carbon ring, with the contact zones (7) of the conductor segments (3) abutting against the contact areas (15) enclosed by the frame-type elevations (27) thus forming electrically-conductive connections;

    insertion of the compound part formed from the conductor blank and the carbon ring into an injection moulding die;

    extrusion of a carrier body (1) made from insulating compression moulding compound onto the compound part in the injection moulding die;

    removal of the unfinished commutator formed from the conductor blank, the carbon ring disc and the extruded carrier body from the injection moulding die;

    opening of the bridge parts (21);

    cutting into the carbon ring between two respective conductor segments (3) as far as the carrier body to form the carbon segments (4).
31. Method according to claim 30,
    characterised in that
    the electrically-conductive connection between the contact zones (7) of the conductor segments (3) and the carbon segments (4) is produced by soldering.
32. Method according to one of claims 30 or 31,
    characterised in that
    both halves of the injection moulding die fit together to form a seal on two annular closed sealing surfaces (23, 24) arranged on both end faces of the conductor blank, each running in a plane standing perpendicular to the axis (2).
33. Method according to claim 32,
    characterised in that
    the two sealing surfaces (23, 24) stand opposite each other.
34. Method according to claim 30,
    characterised in that
    the contact areas (15) of the contact zones (7) of the conductor segments (3), before the joining of the conductor blank with the carbon ring, are machined to a surface roughness of 50-150µm and then provided with a corrosion-resistant metallic coating.
35. Method according to one of claims 30 to 34,
    characterised in that
    when the injection moulding die is closed the cross-over areas (8) of the conductor blank are deformed.

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