DE4024021A1 - Sliding electrically- and heat-conducting article contg. carbon - esp. for transferring electric current with body of filled temp.-resistant conductive synthetic resin bonded to 2nd body - Google Patents

Abstract

Article (I) comprises (A) first electrically- and heat-conductive body comprising filler (II) and temp.-resistant synthetic resin (III), bonded firmly with (B) at least one second electrically- and heat-conductive body which is not the holder of (A). Prepn. of (I) by injection moulding, injection pressing, or impressing, (B) being enclosed with compsn., in non-hardened state of (II) and (III) for prepn. of (A). USE/ADVANTAGE - Transferring electrical current between two surfaces moving relative to each other for vehicles or machines (claimed), e.g., C brushes for stationary D.C. and A.C. current drives, driving motors, small electrical household motors, tools, and vehicle construction, sliding contacts, current collectors for standard gauge and mine railways, trams, trolley buses, crane tracks (claimed), and gantries; also solely mechanical purposes such as (claimed) sliding ring seals and bearings. (I) is more readily prepd., has better sliding and self-lubricating properties, suffers less wear, gives good current transfer, has reduced tendency to sparking and arcing, and greater tolerance to atmospheric conditions such as weather and gases.

Description

The invention relates to one of two ver together Bonded bodies consisting of electrical and heat conductive carbonaceous slider. The application Possibilities of inventive sliders are on the field of transmission of electrical currents and in the field of purely mechanical applications, in particular of Geitring seals and bearings.

Electrically conductive sliders find manifold Use in electrical engineering for power transmission between relatively moving parts. To call Here, for example, carbon brushes for stationary DC and AC drives, for traction motors, for electric small motors in the household, for tools and in vehicle construction, sliding contacts for lifts and cons stands and slips for the pantographs electric tracks, mine cars, trams, O-buses, crane runways, conveyor and loading bridges.

From a good slider is a trouble-free power transfer between the relative to each other moving surfaces with as long as possible Lifetime required. These demands are not easy to fulfill and it depends on the given such as As current, voltage, composition and pairing of slide material and counter drive material, relative velocity, composition of surrounding atmosphere and, where appropriate, installation method and condition of the catenary wire, how far you can get an optimum of the effect in part against approaching operational influences.  

Because of the many different applications possible speeds of electrical sliding contact pieces and the different influence of different operations parameter was a variety of Gleitstücktypen ent wraps. The aim of this development effort was to with increasing technical requirements in the following Score improvements:

• - Abrasion of slider and mating surface
• - Formation of sparks and arcs
• - Transmission of higher currents or services, given if at higher speeds
• - susceptibility to breakage.

Where not already with carbon-based slides was worked, as is the case with many types of brushes Case is, the development proceeded, starting from metal Grinding pieces of steel, copper, bronze or aluminum to grinding pieces made of carbon or graphite. By Combinations of different fillers like coke, part graphitized coke, carbon black, graphite and binders such as Pitches and synthetic resins, with production conditions and the choice of certain geometrical forms arose Variety of special applications adapted sliding piece types. But also the quality of these contact pieces satisfied in many cases not completely. So were for the transmission of higher currents with Metals impregnated varieties or multi-substance Grinding pieces created (DE 6 91 555, sheet 1, column 1). Here one used the earlier knowledge and Experience with sliders made of metal. At a Embodiment extends the copper socket to the current decreasing area high, so that a substantial part  of the current is transmitted through the copper frame (Company brochure of Ringsdorff-Werke GmbH, Ringsdorff- Carbon abrasive pieces, page 2, column 2 and page 4, Column 1). However, this solution takes the metal slide own disadvantage of greater wear of the mating material by a higher coefficient of friction and higher sparking in purchase. To the wear too were also carbon abrasive pieces with Coatings of copper and hard materials such. B. Hartchrom or molybdenum provided (DE 7 28 468). Around Here had to keep the attack of the contact wire low, had to the running surfaces of the grinding pieces are polished and lubricated become. When operating O-buses fall Abrieberschei particularly strong, because there is the power Zuleitungs- or contact wire in a shoe along a narrow slideway is performed. To reduce Abrasion has been demonstrated for such applications hit the contact wire in the sanding shoe over the circle to guide surfaces disc-shaped contact body, the are rotatably mounted and their axes of rotation relative to the Catenary axis are laterally offset, so that the driving wire the contact body in operation rotated and not on them grinds (DE 6 90 904). This solution However, it requires a lot of technical effort.

In addition to the applications in the electrical field are Carbon-containing sliders also for purely mechanical Applications such as plain bearings, slide rails and Sealing elements suitable in vehicle and mechanical engineering. This suitability is based on the combination of the following, favorable characteristics: good temperature resistance, good sliding behavior in dry and wet running, smaller Coefficient of thermal expansion, excellent chemical Resistance and good thermal conductivity. carbon haltige sliders can as a result at Gleitbe  movements in lubrication unfavorable or corro dying media and used in dry running. Naturally, the stress is on the sliding one another Materials in such applications high and the Shelf life limited accordingly. In addition, warehouse and sliding elements be worked precisely. Your Production therefore requires a high production expenditure. The goal of further development efforts is as a result, the sliding properties of carbonaceous Sliders continue to improve and manufacture to reduce costs.

It is an object of the invention to provide a slider for the Power transmission between two relative to each other to create moving parts, the one

• - less abrasion at
• - improved sliding properties while maintaining
• - a good power transmission capability and a
• - low tendency to spark and arcing such as
• - good adaptability to different atmospheric Conditions such as weather conditions and gases and has different operating requirements and that
• - With less effort than sliding body after the State of the art can be produced.

Another object of the invention is a sliding piece for use in mechanical seals and To create bearings as well as a slide, the

• - improved self-lubricating properties  
• - a lower coefficient of friction while maintaining the other advantageous properties of known sliding has pieces and
• - With less effort than sliding body by the state the technology can be produced.

The object is achieved in that one from a filler and a temperature resistant Resin existing first electrical and heat conductive body with at least one second electrically and thermally conductive body, not the Version of the first body is firmly connected.

Such a slider is constructed so that the first of a filler and a hardened synthetic resin existing body the second body, the one or also may be multi-part, at least partially encloses and fixed in its position. The one from the first body closed parts of the second body can of be any shape. In general, but one multiple forms such as strips, cuboids, cubes or cylinders used. These parts can with longitudinal grooves, transverse grooves, Be provided with grooves and fillets. Other bodies configurations are applicable for special purposes, in the production, however, more expensive. When it comes to carbonaceous bodies, they become after stranded, swaged or isostatically pressed parts carbonating or carbonating and Graphitieren, if necessary by dividing and spanab receive lifting edit. Become metallic parts from semi-finished profiles by machining or after the Process of sintered metal technology in per se known Made way. The parts (the same applies in the following each also for a part) of the second body can  enforce the enclosing first body, so that they over an area or two opposite ones Protruding surfaces of the first body. You can also with two opposite surfaces or one upper Close the area of the enclosing body exactly and in these places one consisting of both bodies form continuous surface. Important for the inventive design is that the surfaces of the enclosed body on at least one side for the Production of contacts with a mating material exposed. For a particularly advantageous embodiment form must be opposite, not from first body exposed surfaces and exposed with the surfaces of the first body a continuous Form surface. The latter version is for electricity customer grinding pieces for electric webs, for Crane systems and for O-buses use.

Such composites may be suitable for mounting on their Location with a shoe or other holding be provided device. It's also the fasteners by any other appropriate means, namely mechanical fasteners such as screws or also applicable by gluing.

The selection of the second, from the first body to closing body depends on the material variety and its orientation in the first body after the Requirements of the purpose of the application. such Requirements may, for. B. a good electrical Leit ability to have good electrical conductivity in Compound with a certain polishing effect, eventually still associated with a lubricating effect, the sub suppression of arcing and arcing, certain Warming characteristics, good sliding properties alone  or in connection with chemical resistance or Be combinations of it. Materials that one Variety of application profiles must be sufficient naturally a variety of recipes, raw and Auxiliaries. For one thing, the body can look Metal, whereby the metals copper, lead, tin, Antimony, aluminum and silver and alloys of these Metals have been found to be suitable. For another the bodies of carbonized or carbonized and graphitized carbon moldings are manufactured. Such precursor bodies are made of one or more carbonaceous filler (s), a carbonaceous material Binder or binder system and, where appropriate, auxiliaries for molding like lubricants and for that Carbonizing produced as condensing agent. When Fillers are not electrographite, natural graphite graphitized carbon such as coke or soot and part graphitized carbon such as carbonized and afterwards milled mixtures of a carbonizable binder and a graphite filler proven. As binders are stone coal tar pitches, petrol pitches or curable resins such as Phenol, epoxy and furan resins suitable.

The carbonized and the graphitized bodies are porous. That's why they can change their own schaften, z. B. to their electrical and thermal conductivity increase their polish effect, or to improve their polishing effect, be impregnated with metals or metal alloys.

Depend on their method of production carbonaceous bodies a more or less strong Anisotropy of the properties. Particularly pronounced this is with extruded material. It is now advantageous, this anisotropy in positioning the second body in the first enclosing bodies  targeted use. This is how to make abrasive strips and Grinding pieces for the electric current decrease so too position search that the pressing direction of the molded body perpendicular to the power line, z. B. the driving line wire stands, since thus the direction of the Current flow with the direction of maximum electrical Conductor of the slider covers.

The first, electricity and heat conducting body exists from a synthetic resin binder and a carbonaceous Ink pen. As binders are on the one hand thermoplastics with a high softening point such as polyamides, polyimides, Polyphenylene sulfide, polytetrafluoroethylene, perfluorinated and partially fluorinated ethylene / propylene copolymers, polyaryl amides and polyetheretherketones and on the other hand hardens bare thermosets such as phenolic resins, epoxy resins and Furan resins suitable. As filler is expediently finely ground electrographite, natural graphite, not graphitized carbon such as. As coke or for cases where a particularly good electrical and thermal conductivity required or certain sliding properties to be adjusted, a carbon-metal powder mixture used. Under carbon here are all To understand types of graphite and coke. As metals especially copper, brass, bronze, aluminum, Aluminum-magnesium alloys, silver, lead, tin and Antimony and alloys of the latter four metals Use. Preferred fillers in the context of this invention are graphite powder.

A special feature of the mixed mass of synthetic resin binder and carbonaceous filler is that they easily can be extruded and injection-molded. Especially after Injection molding can also be complicated parts, which are not produced by conventional pressing  can be manufactured with high accuracy. A additional machining is in most Cases no longer necessary. For the invention is further important that with this mass also other bodies true to size and molded and cohesively can. After molding, also in heated factory be carried out so that partial hardening of the Mass is done, the parts are under temperature or catalytically cured. The so forth provided parts have excellent dry running and Sliding properties, excellent shape retention even under load, a good heat and electrical conductivity, a good chemical resistant speed, good temperature resistance and a low coefficient of thermal expansion. you are with less effort than carbonized or graphi produced parts.

Electric current transmitting sliding contact pieces for Vehicles and machines and sliding contact pieces for Mechanical seals, slide rails and bearings must be in diverse and sometimes complicated way others Parts or application requirements. This is a complex processing in tight tolerances necessary. It is an advantage of the invention that a part the machining steps can be omitted if the sliding Contact pieces, in the above always as the second electrically and thermally conductive body were designated with the cheaper Kunstharzbinderhaltigen mass after the less expensive injection molding or another suitable pressing methods such as transfer molding, pressing or hot pressing with a precision formed part can be surrounded. This gives a composite body, the one conventional but with less Bearbei tion costs produced inner part and a  outer, consisting of a cheaper material contains pressed part. Overall, this results a reduction of the effort. The inner, second part It can also be made smaller, because it has surprisingly found that the outer, So the part of the first electric and thermally conductive capable body part of the functions of the internal Part, so the second electrically and thermally conductive Able to take over body. For this functional Collaboration even results in an additional one Improvement, as in field tests with pantographs was determined: the gliding have been significantly improved and the plant wear drastically reduced, while in the other operating data no changes detected were.

The invention will be described below with reference to two examples and explained in more detail by drawings: Under the slip pieces are pantograph slides in O-buses exposed to heavy wear. of semi abrasive pieces according to the invention were in the O-bus operation in comparison to the prior art ent speaking grinding pieces under the usual Road traffic conditions tested.

comparison

Due to the ongoing records of traffic operation, with whose O-buses the tests were carried out conventional grinding pieces have the following average service life:

in dry weather: 5 days 600 km driven route in wet weather: 1 day 150 km driven route

example 1

In a articulated O-bus, total weight 17 t, engines Power 2 × 100 kW, mains, DC, 600 V ± 20%, Max. 400 A, were inventive pantograph Grinding pieces from a first enclosing body based on phenolic resin / graphite filler, the second electrically and thermally conductive body five cylinders shaped cones of a commercially available hard coal type (RH 92 of Ringsdorff-Werke GmbH), with the following Result driven:

Table 1

The stronger wear of the right built-in grinding Pieces is based on peculiarities of O-bus operation Relationship of contact wire position to lane or on the Due to road inclination.

The average mileage per slip piece was in this experiment including all one River sizes 2235 km.

Example 2

In a articulated O-bus, total weight 17 t, engines power 175 kW, mains, direct current, 600 V ± 20%, max. 400 A, were the same pantograph grinding pieces as used in Example 1 and with the following result hazards

Table 2

The average mileage per slip piece was in this case, again including all Influences, 1746 km.

The examples show, despite the wide fluctuation range, which is normal in O-bus operation, in impressive full of the improvements made by the invention appropriate grinding pieces. The service life can be reduced by ver Use of such grinding pieces in normal driving with a change between dry and wet weather be increased by 3 to 4 times.

Fig. 1 is a contact strip (1) according to the prior art in a plan view, a longitudinal side view (Fig. 1a) and a front view Ib (FIG. 1b) again. The sliding piece ( 1 ) has on its upper side a running in the direction of the longitudinal axis, by going arcuate elaborated grinding groove ( 2 ) for the catenary wire, which is not shown. The side walls ( 3 , 3 ') are chamfered from the base outgoing converging towards each other, the longitudinal edges ( 4 , 4 ') are beveled and the ends ( 5 , 5 ') have Teilabschrägungen ( 6 , 6 ') of different Steepness.

Fig. 2 shows an inventive sliding piece ( 7 ) in plan view as it is indicated in principle in Examples 1 and 2. For further explanation, a vertical longitudinal section AA '( FIG. 2a) and a cross section along the axis BB' ( FIG. 2b) are reproduced here. This grinding piece ( 7 ) has the same geometric shape as the grinding piece ( 1 ) according to the prior art ( Fig. 1, 1a, 1b). In contrast to the known contact strip ( 1 ), the new contact piece ( 7 ) four cylindrical inserts ( 8 ) made of hard coal, so from a material of the grinding pieces may consist of the prior art. These four inserts ( 8 ) have been surrounded by injection molding with a phenol resin and graphite powder-containing mass, so that the insert body ( 8 ) of an injection-molded and cured, electrically and thermally conductive body ( 9 ) are surrounded. The upper and lower surfaces ( 10 , 10 ') of the over-molded A sets ( 8 ) are exposed and close with the ent speaking surfaces ( 11 , 11 ') of the surrounding body ( 9 ).

Figures 3, 3a and 3b illustrate another embodiment of a sliding piece ( 7 ) according to the invention. Fig. 3 is a plan view, Fig. 3a is a vertical longitudinal section AA 'and Fig. 3b is a cross section taken along the line BB' in Fig. 3a. The geometric shape is in turn the same as that of the grinding piece ( 1 ) in Figs. 1, 1a and 1b. In the present case, a one-piece body ( 12 ) of prior art Schleifstückmaterial by injection molding and after subsequent curing with a first electrically and thermally conductive body ( 9 ) surrounded by a temperature-resistant resin and a carbonaceous filler. The enclosed body ( 12 ) has an arcuate longitudinal groove ( 2 ) for the acquisition of the contact wire, in addition a plurality of transverse to the longitudinal axis grooves ( 13 ) and two laterally mounted longitudinal grooves ( 14 , 14 '). It corresponds to the body shown in FIG. 4d. The transverse ( 13 ) and the longitudinal grooves ( 14 , 14 ') are filled in the finished composite body ( 7 ) with the mass of the enclosing body ( 9 ). In basically the same way, bodies as they are shown by way of example in FIGS. 4a, 4b and 4c can be embedded in the synthetic resin / filler mass.

Due to strong profiling, z. B. by mounting grooves as shown in Figs. 4b, 4c and 4d, the sliding properties and the electrical heat transfer for the composite body can be improved and the wear can be further reduced. For vibration-rich operation is caused by the profiling better locking of the inner body an advantage.

Claims (21)

1. consisting of two interconnected bodies, electrically and heat conductive, carbon-containing slider, characterized in that
a consisting of a filler and a temperature-resistant synthetic resin first electrically thermally conductive body
with at least one second electrically and thermally conductive body that is not the version of the first body, is firmly connected. 2. Slider according to claim 1, characterized in that the filler of the first electrically and thermally conductive Body a filler from the group electrographite, Natural graphite is. 3. Slider according to claim 1, characterized in that the filler of the first electrically and thermally conductive Body is not graphitized carbon. 4. Slider according to claim 1, characterized in that the filler of the first electric and thermally conductive capable body a mixture of a carbon powder and a metal or a metal alloy is.   5. Slider according to claims 1 to 4, characterized in that the resin binder of the first electric and heat conductive body is a curable resin. Slider according to claims 1 to 5, characterized in that the resin binder of the first electric and heat conductive body is a phenolic resin. 7. Slider according to claims 1 to 6, characterized in that the second electrically and thermally conductive body by carbonizing a shaped article from a carbonaceous binder and a carbon containing filler is obtained body. 8. Slider according to claims 1 to 7, characterized in that the second electrically and thermally conductive body by carbonizing a shaped article with a binder obtained from the group pitch and curable resins Body is. 9. Slider according to claims 7 to 8, characterized in that the second electrically and thermally conductive body a Filler from the group of electrographite and natural graphite Has. 10. Slider according to claims 7 to 8, characterized in that the second electrically and thermally conductive body a Filler from the group of non-graphitized carbon Has.   11. Slider according to claims 1 to 10, characterized in that the second electrically and thermally conductive body with a metal or a metal alloy impregnated is. 12. Slider according to claim 1 to 6, characterized in that the second electrically and thermally conductive body a metal or an alloy. Slider according to claims 1 to 6 and 12, characterized in that the second electrically and thermally conductive body from a metal from the group copper, lead, tin, Antimony, silver, aluminum or an alloy one of these metals is. 14. Slider according to claim 1, characterized in that the second electrically and thermally conductive body of the first electrically conductive body so is enclosed, that between two bodies one electrical and a heat flow can flow. 15. Slider according to claim 14, characterized in that the second electrically and thermally conductive body the surrounding him first electrically conductive Body in one or more connecting lines of two opposite surfaces so interspersed that he the passageways in the opposite Surfaces exposed, but at no point over this upper predetermined by the first body surfaces.   16. Slider according to claim 14, characterized in that the second electrically and thermally conductive body the him enclosing first electrically and thermally conductive capable body in one or more connection lines of two opposing surfaces so through that he puts in the passages in the opposite surfaces exposed and over at least one of them passing through the first body voted surfaces sticking out. 17. Slider according to claims 1 to 16, characterized in that the second electrically and thermally conductive body a part whose surfaces are either even are. 18. Slider according to claims 1 to 16, characterized in that the second electrically and thermally conductive body more than one part. 19. Slider according to claims 1 to 18, characterized in that it is an electric current transmitting sliding contact piece for vehicles and machines, in particular the group is electric railways, o-buses, cranes. 20. Slider according to claims 1 to 18, characterized in that it is a sliding contact piece for vehicles and machines, especially for mechanical seals, slide rails and camp is.   21. A method for producing a slider according to Claim 1, characterized in that the second electrically and thermally conductive body with made of a filler and a temperature resistant Synthetic resin existing mixed precursor mass for the production of the first electrically and thermally conductive capable body in the unfixed state Injection molding, transfer molding or pressing around is closed.