GB1568241A - Sintered brush for a dynamo electric machine - Google Patents
Sintered brush for a dynamo electric machine Download PDFInfo
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- GB1568241A GB1568241A GB11317/76A GB1131776A GB1568241A GB 1568241 A GB1568241 A GB 1568241A GB 11317/76 A GB11317/76 A GB 11317/76A GB 1131776 A GB1131776 A GB 1131776A GB 1568241 A GB1568241 A GB 1568241A
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- Prior art keywords
- brush
- silicon carbide
- weight
- copper
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 239000000203 mixture Substances 0.000 claims description 40
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 40
- 239000002245 particle Substances 0.000 claims description 32
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 30
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 29
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 26
- 229910052802 copper Inorganic materials 0.000 claims description 21
- 239000010949 copper Substances 0.000 claims description 21
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 15
- 229910052799 carbon Inorganic materials 0.000 claims description 13
- 239000000843 powder Substances 0.000 claims description 11
- 238000005245 sintering Methods 0.000 claims description 6
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims description 5
- 239000000314 lubricant Substances 0.000 claims description 4
- 230000001747 exhibiting effect Effects 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 229910010293 ceramic material Inorganic materials 0.000 claims description 2
- 238000007373 indentation Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000005056 compaction Methods 0.000 claims 1
- 229910002804 graphite Inorganic materials 0.000 description 11
- 239000010439 graphite Substances 0.000 description 11
- 239000012535 impurity Substances 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 238000003921 particle size analysis Methods 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000004380 ashing Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005029 sieve analysis Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
- H01R43/12—Manufacture of brushes
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Motor Or Generator Current Collectors (AREA)
Description
(54) A SINTERED BRUSH FOR A DYNAMO ELECTRIC
MACHINE
(71) We, LUCAS INDUSTRIES LIMITED, of Great King Street,
Birmingham, a British Company, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be perfor ned, to be particularly described in and by the following statement:- This invention relates to a sintered brush for a dynamo electric machine.
A brush for a dynamo electric machine, according to the invention, includes a sintered composition containing copper, carbon and silicon carbide.
Preferably, the sintered composition has the following composition by weight:
Carbon 1--8% Silicon Carbide 0.855.1% Tin 0l% Lead 7.515.3%, and
Copper remainder.
More preferably, the sintered composition consists of 4% by weight carbon,
1.7% by weight silicon carbide, 2.55% by weight tin and 12.75% by weight lead, the
remainder being copper.
The invention further resides in a method of producing a brush for a dynamo
electric machine, comprising the step of sintering a compacted powder mixture
containing copper, carbon and silicon carbide.
Preferably, the silicon carbide powder in said mixture has a mean particle size between 9 and 18 microns, more preferably has a mean particle size of 12-18 microns, and most preferably a mean particle size of 13 microns.
Preferably, the copper powder in said mixture has a mean particle size of less than 106 microns and more preferably has a mean particle size of 53 microns.
Preferably, the electrical lead for the brush is metallurgically bonded thereto during sintering of said mixture.
In a first example of the invention, a brush for a dynamo electric machine was produced from a powder mixture having the following composition by weight: Copper 79%,
Lead 12.75%, Tin 2.55, Graphite 4.0%, and
Silicon Carbide 1.7 ,O.
The mixture also contained 0.59 parts by weight of a zinc stearate lubricant for every 100 parts by weight of the composition defined above.
In the mixture, the copper powder was electrolytic copper and had a purity of at least 99%, the major impurities being lead (maximum of 0.2% by weight) and oxygen (maximum 0.2% by weight). A particle size analysis of the copper powder showed that not more than 0.2 ó by weight had a size in excess of 53 microns.
The lead powder in the mixture was atomised lead and had a purity of at least 99-95 Ó so that the effect of any impurities was negligible. A particle size analysis showed that 1% by weight of the lead powder had a prticle size in excess of 150 microns, 10% by weight had a particle size between 75 and 150 microns, and 15% by weight had a particle size between 45 and 75 microns, the particle size of the remainder being 45 microns or below.
The tin powder was that supplied as 53 micron tin and had a purity of at least 990; so that again the effect of any impurities was negligible. A particle size showed that about 97.5% by weight of the powder had a particle size below 53 microns.
The graphite powder employed was 45 micron natural flake, micronised graphite, the particle size being confirmed by a sieve analysis which showed that 99.5% by weight of the powder had a particle size below 45 microns. The graphite powder had a purity of 9697%, the impurities being typically after ashing 1.4% by weight silica, 0.93% by weight alumina, 0.2% by weight calcia, 0.07% by weight each of sulphur and magnesia, 0.68% by weight of iron and not more than 0.2% by weight moisture.
The silicon carbide powder had a mean particle size of 13 microns and was supplied by the Carborundum Company Limited of Manchester as type F500. The purity of the silicon carbide powder was 98.7% and the impurities present were 0.48% by weight silica, 0.3% by weight silicon, 0.9% by weight iron, 0.1% by weight aluminium and 0.3% by weight carbon.
The zinc stearate lubricant was that supplied by Witco Chemical Limited, as technical grade 1/s.
To produce the required mixture, the as-supplied powders were introduced in the required proportions into a Turbula mixer, and mixed for 100 minutes. The resultant powder was then poured into a die cavity defined within a tungsten carbide die whereafter one end of an electrical lead formed of tough pitch high conductiyity copper was inserted into the powder in the die cavity. The powder was subsequently pressed around the lead using an applied pressure of 10-35 tons
F/in2, preferably 19 tons F/in2, and after removal from the die cavity, the assembly was heated in a nitrogen atmosphere. Initially heating was effected at 4500C for 15 minutes to remove the lubricant, whereafter the temperature was raised to the required sintering value of between 600 and 8800 C, preferably 8000 C, and retained at this upper value for 20 minutes. On cooling to room temperature, the resultant component was ready for use as a brush for a dynamo electric machine.
The brush produced according to the above example was intended for use with a commutator of the kind in which the insulating material between adjacent conductive segments extended flush with the brush engaging surfaces of the segments. It was therefore necessary that the brush was able to cope with the variation in material at the brush engaging surface of the commutator while at the same time exhibiting a low wear rate of the brush together with a low rate of commutator wear. When the brush of the above example was tested with such a commutator, it was found that the brush operated satisfactorily and both the commutator and the brush exhibited a low wear rate.
The method of the first example was then repeated with a plurality of further starting compositions in which the particle size of the silicon carbide powder was varied between 3 and 23 microns. The resultant brushes were then tested in a road vehicle starter motor employing a commutator of the kind specified and the amount of wear experienced by the brushes and the commutator were measured after about 2030000 operations of the motor. The results of these tests, together with the corresponding results obtained with the brush described above are given in
Table 1 below.
TABLE 1
Maximum blush wear rate/1000 Total Brush Mean particle size No. of operations commutator No. (Mi clons) operations (inch) wear (inch) 1 3 30000 7 x 10-3 7 X 10-3 2 3 30000 6.6 x 10-3 3 x 10-3 3 3 31718 8.9 x 10-3 1 X 10-2 4 3 30243 9.4 x 10-3 5 x 10-2 5 6.5 20127 6.7 x 10-3 2X10-3 6 6.5 20025 5.2 x 10-3 4 x 10-3 7 6.5 30513 8.4 X 10-3 4 x 10-3 8 6.5 24150 7.2 x 10-3 4 x 10-3 9 9 25820 6.9 x 10-3 1.2 x 10-2 10 9 30458 5.6 x 10-3 6 x 10-3 11 12 34600 4.1 x 10-3 2.3 x 10-2 12 13 21244 3.8 x 10-3 1x10-2 13 13 33360 5.0 x 10-3 9 x 10-3 14 13 30927 4.6 x 10-3 1.6 x 10-2 15 17 30000 6.2 x 10-3 2 x 10-2 16 17 18556 4.8 x 10-3 1.6 x 10-2 17 18 30132 4.2 x 10-3 8 x 10-3 18 18 30000 4.0 x 10-3 8 x 10-3 19 20 30012 4.9 x 10-3 9.6 x 10-2 20 20 30011 6.6 x 10-3 9 x 10-2 21 23 27096 6.5 x 10-3 9 x 10-2 In the above Table, the figures given for maximum brush wear rate were obtained when four samples of each type of brush were mounted in a starter motor and indicate the wear rate for the sample which had undergone the most wear.
From the results listed it will be seen that the lowest values for the brush wear rate were obtained when the silicon carbide particle size was from 9 to 18 microns and, in particular 12 to 18 microns, it being appreciated that a maximum brush wear rate of not more than 5 x 10-3 inch/1000 operations represents a highly attractive brush from a commercial viewpoint. It will also be seen from Table 1 that the commutator wear was very low for each type of brush tested, except in the case of the 20 and 23 micron samples where considerable wear of the commutator was evident.
In a second example of the present invention, a plurality of further brushes were produced by repeating the procedure of the first example but with the concentration of the silicon carbide in the starting mixture being varied. In each case, the concentration of the copper powder was adjusted to take account of the silicon carbide variation and the particle size of the silicon carbide powder: was maintained at 13 microns. As in the previous example, each of the resultant brushes was then tested in a starter motor employing a commutator of the kind specified.
The results are summarised in Table 2.
TABLE 2
Maximum brush Silicon Carbide wear rate 1000/ Total Brush Concentration No. of operations commutator No. (So) by weight operation-s (inch) wear (inch) 22 0 20,000 1.4 x 10-2 6 x 10-3 23 0.4 30,608 6.9 x 10-3 2.5 x 10-2 24 0.4 31,025 6.68 x 10-3 1.0 x 10-3 25 0.6 31,871 8.74 x 10-3 1.5 x 10-2 26 0.6 30,781 6.80 x 10-3 1.5 x 102 27 0.7 30,601 5.48 x 10-3 6 x 10-3 28 0.7 32,904 5.54 x 10-3 3.4 x 10-2 29 0.85 25,795 3.96 x 10-3 7 x 1O-3 30 0.85 31,037 5.38 x 10-3 8 x 10-3 31 1.70 33,360 5.1 x 10-3 9x10-J 32 1.70 30,927 .4.67 x 10-3 1.6 x 10-2 33 3.40 30,000 6.26 x 10-3 1.5 x 10-2 34 3.40 30,875 3.89 x 10-3 1.5 x 10-2 35 4.25 30,190 8.5 x 10-3 6.0 x 102 36 4.25 30,037 8.86 x 10-3 5.8 x 10-2 37 5.1 30,146 6.26 x 10-3 1.4 x 10.2 38 5.1 32,246 7.22 x 10-3 1.5 X 10-2 39 8.5 36,990 1.0 x 1-2 3.8 x 102 40 8.5 36,250 1.01 x 10-2 3.7 x 10-2 From Table 2 it will be seen that the lowest values for the maximum brush wear rate were obtained when the silicon carbide concentration was between 0.85% and 3.4%. A comparable brush formulation containing 18 micron silicon carbide gave low values of brush wear up to a 5.1% weight concentration. In each case the commutator wear was low.
In a third example, a plurality of brushes were produced from starting mixtures containing the same quantities of tin and lead as in the above examples, 1.7% by weight of 13 micron particle size silicon carbide and varying amounts of graphite (99.5% having a particle size below 45 microns), the remainder of each mixture again being copper. The resultant brushes were subjected to the tests outlined above and the results are given in Table 3.
TABLE 3
Maximum brush Graphite wear rate/1000 Total Brush concentration No. of operations commutator No. (% by weight) operations (inch) wear (inch) 41 0 3,145 3. x 10-2 42 0 16,070 1.68 x 10 2 8 x 10-3 43 2 30,035 5.43 X 10-3 1.2 X 10-2 44 2 30,194 7.82 x 10-3 1.5 x 10-2 45 2.5 30,265 5.39 x 10-3 6.0 x 10-3 46 3.0 30,151 6.34 x 10-3 9 x 10-3 47 3.0 33,756 4.24 x 10-J 1.5 x 10-2 48 4.0 33,360 5.1x10-J 9 x 1C3 49 4.0 30,927 4.67 x 10-3 1.6 x 10-2 50 4.0 21,244 3.8 x 10-3 1.0 x 10-2 51 5.0 30,025 8.14 x 10-3 1.5 x 10-2 52 5.0 31,610 5.6 x 10-3 1.0 x 10-2 53 6.0 30,000 7.16 x 10-3 7 x 10-3 54 6.0 30,098 5.49 x 10-3 1x10-2 From Table 3 it will be seen that the brush wear rate was high when graphite was absent, decreased as the graphite concentration was increased to 4.0% by weight, and rose again when the graphite concentration reached 6% by weight. In each case the commutator wear was low. A similar pattern was observed when 18 micron silicon carbide was used, all other concentrations and particle sizes remaining as in the third example. Thus the brush wear rate fell from 6.4-9.4 x 10-3in/1000 operations when 1% by weight of graphite was used to a minimum of 4--4.6 x 10-3in/1000 operations when 4% by weight of graphite was used, but increased again significantly when the graphite concentration rose above 8% by weight.
In a fourth example, the process of the preceding example was repeated using 18 micron particle size silicon carbide and with the graphite concentration being maintained at the optimum value of 4% by weight and with the quantities of tin and lead being varied. The resultant brushes were tested as before and the results are shown in Table 4.
TABL.E 4
Maximum brush wear rate/ 1000 Total Brush Tin Conc. Lead Conc. No. of operations commutator No. % by weight % by weight operations (inch) wear (inch) 55 0 15.3 20000 6.5 x 10-3 6 x 10 3 56 0 15.3 20235 4.6 x 10-3 6 x 10'3 57 1 14.3 116.40 4.3 x 10-3 1 x 102 58 1 1.4.3 22000 5.6 x 10-3 5 x 10 3 59 2.55 12.75 30132 4.2 x 10-3 8 x 10-3 60 2.55 12.75 31043 4.5 x 10-3 8 x 10-3 61 2.55 12.75 30000 4 x 10-3 3 x 10 62 5 10.3 20000 7.5 x 10-3 7 x 10-3 63 5 10.3 20000 7.5 x 10-3 5 x 10-3 From Table 4 it will be seen that the brush wear rate decreased as the tin content was increased up to 2.55% by weight but that this improvement had disappeared by the time the content had reached 5% by weight. It is, however, to be noted that the wear rate in the absence of tin would have been acceptable for many applications. Again the commutator wear was low for each brush.
In addition to the samples shown in Table 4, further samples using 13 micron silicon carbide were tested, in which the lead content was reduced to 9% by weight and 7.5% by weight respectively. In each of these further examples the tin concentration was maintained at 2.55% by weight, and so the copper concentration was increased by 3.75% by weight and 5.25% by weight respectively to make up the deficit. These further samples showed both low brush wear rate and low commutator wear. However, when the lead content was reduced to the order of 6% by weight with the copper having been increased by 6.75% by weight, heavy brush and commutator wear was observed when such brushes were tested.
In a fifth example, the effect of varying the copper particle size was investigated using a starting mixture as described in the first example but with the particle size of the silicon carbide powder being 18 microns. The results are summarised in Table 5.
TABLE 5
Maximum brush wear rate/1000 Total Brush Copper Particle No. of operation-s commutator No. size operations (inch) wear (inch) 64 99.8% 531l 30132 4.2 X 10-3 8 x 10'3 65 99.8% ' 5311 31043 4.7 x 10-3 8 x 10-3 66 99.8% < < 53 , 30000 3.5 x 10-3 3 x 10-3 67 30-45% < 451 20000 4.8 X 10-3 5 x 10-3 68 30-456 < 4511 20000 3.4 x 10-3 3 x 10-3 69 > 106 21132 1.45 x i().2 4 x 10-3 70 > 1061* 10116 1.34 x 10-2 4 x 10-3 71 < 75y 20083 5.6 x 10-3 3 x 10-3 72 < 451* 20003 8.5 x 10-3 5 x 10-3 73 < 451l 20066 4.8 x 10-3 5 x 10-3 From Table 5 it will be seen that the preferred particle size for the copper powder is less than 106 microns and particularly below 53 microns.
In each of the brushes produced according to the above examples, the silicon carbide has defined the required hard phase of the brush. It is however, to be appreciated that silicon carbide powder has an indentation hardness (VPN) value between 1890 and 3430 (mean 2876) when using a 200g load, and is therefore normally used for cutting tools and for its abrasive properties. However, its inclusion in the material of the invention has allowed an electrical brush to be produced exhibiting very little wear not only of the brush itself, but also of the copper commutator upon which it rubs. Even though it performed well as an electrical brush, it was feared that the life of the tungsten carbide tools used for producing such brushes would suffer (the hardness of tungsten carbide is less than silicon carbide). It has been found, however, that the tool life is conducive to high quantity production. Moreover, it is to be understood that, although silicon carbide is a ceramic material, its resistivity of 10-3-10-1 ohm cm is sufficiently low for it to act as an electrically conductive component of the sintered brush.
WHAT WE CLAIM IS: l. A brush for a dynamo electric machine including a sintered composition containing copper, carbon and silicon carbide.
2. A brush as claimed in Claim l, wherein the sintered composition has the following composition by weight: Carbon 1-8%
Silicon Carbide 0.85-5.1%
Tin 0-4%
Lead 7.5-15.3%, and
Copper remainder 3. A brush as claimed in Claim 2, wherein the sintered composition consists of 4 by weight carbon, 1.7% by weight silicon carbide, 2.55"d by weight tin and 12.75% by weight lead, the remainder being copper.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (16)
- **WARNING** start of CLMS field may overlap end of DESC **.TABLE 5Maximum brush wear rate/1000 Total Brush Copper Particle No. of operation-s commutator No. size operations (inch) wear (inch) 64 99.8% 531l 30132 4.2 X 10-3 8 x 10'3 65 99.8% ' 5311 31043 4.7 x 10-3 8 x 10-3 66 99.8% < < 53 , 30000 3.5 x 10-3 3 x 10-3 67 30-45% < 451 20000 4.8 X 10-3 5 x 10-3 68 30-456 < 4511 20000 3.4 x 10-3 3 x 10-3 69 > 106 21132 1.45 x i().2 4 x 10-3 70 > 1061* 10116 1.34 x 10-2 4 x 10-3 71 < 75y 20083 5.6 x 10-3 3 x 10-3 72 < 451* 20003 8.5 x 10-3 5 x 10-3 73 < 451l 20066 4.8 x 10-3 5 x 10-3 From Table 5 it will be seen that the preferred particle size for the copper powder is less than106 microns and particularly below 53 microns.In each of the brushes produced according to the above examples, the silicon carbide has defined the required hard phase of the brush. It is however, to be appreciated that silicon carbide powder has an indentation hardness (VPN) value between 1890 and 3430 (mean 2876) when using a 200g load, and is therefore normally used for cutting tools and for its abrasive properties. However, its inclusion in the material of the invention has allowed an electrical brush to be produced exhibiting very little wear not only of the brush itself, but also of the copper commutator upon which it rubs. Even though it performed well as an electrical brush, it was feared that the life of the tungsten carbide tools used for producing such brushes would suffer (the hardness of tungsten carbide is less than silicon carbide). It has been found, however, that the tool life is conducive to high quantity production. Moreover, it is to be understood that, although silicon carbide is a ceramic material, its resistivity of 10-3-10-1 ohm cm is sufficiently low for it to act as an electrically conductive component of the sintered brush.WHAT WE CLAIM IS: l. A brush for a dynamo electric machine including a sintered composition containing copper, carbon and silicon carbide.
- 2. A brush as claimed in Claim l, wherein the sintered composition has the following composition by weight: Carbon 1-8% Silicon Carbide 0.85-5.1% Tin 0-4% Lead 7.5-15.3%, and Copper remainder
- 3. A brush as claimed in Claim 2, wherein the sintered composition consists of 4 Ó by weight carbon, 1.7% by weight silicon carbide, 2.55"d by weight tin and 12.75% by weight lead, the remainder being copper.
- 4. A method of producing a brush for a dynamo electric machine, comprisingthe step of sintering a compacted powder mixture containing copper, carbon and silicon carbide.
- 5. A method as claimed in Claim 4, wherein the powder mixture has the following composition by weight: Carbon 1--8% Silicon Carbide 0.855.1% Tin 04% Lead 7.515.3%, and Copper remainder
- 6. A method as claimed in Claim 4 or Claim 5, wherein the silicon carbide powder in said mixture has a mean particle size between 9 and 18 microns.
- 7. A method as claimed in any one of Claims 4 to 6, wherein the silicon carbide powder in said mixture has a mean particle size between 12 and 18 microns.
- 8. A method as claimed in any one of Claims 4 to 7 wherein the silicon carbide powder in said mixture has a mean particle size of 13 microns.
- 9. A method as claimed in any one of Claims 4 to 8, wherein the copper powder in said mixture has a mean particle size of less than 106 microns.
- 10. A method as claimed in any one of Claims 4 to 9, wherein the copper powder in said mixture has a mean particle size of less than 53 microns.
- 11. A brush as claimed in any one of Claims 4 to 10, wherein the electrical lead for the brush is metallurgically bonded thereto during sintering of said mixture.
- 12. A method as claimed in any one of Claims 4 to 11, wherein the powder mixture also contain a lubricant which aids compaction of the mixture and is removed during the sintering step.
- 13. A method as claimed in Claim 4, of producing a brush for a dynamo electric machine, substantially as hereinbefore described.
- 14. A brush for a dynamo electric machine produced by a method as claimed in any one of Claims 4 to 13.
- 15. A brush for a dynamo electric machine as claimed in Claim 1, substantially as hereinbefore described.
- 16. A dynamo electric machine including a brush as claimed in any one of Claims 1 to 3 or Claim 14 or Claim 15.
Priority Applications (13)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB11317/76A GB1568241A (en) | 1976-03-20 | 1976-03-20 | Sintered brush for a dynamo electric machine |
| ZA00771497A ZA771497B (en) | 1976-03-20 | 1977-03-11 | A sintered composition |
| US05/777,535 US4101453A (en) | 1976-03-20 | 1977-03-14 | Sintered composition |
| IN369/CAL/77A IN146179B (en) | 1976-03-20 | 1977-03-14 | |
| AU23303/77A AU503785B2 (en) | 1976-03-20 | 1977-03-16 | A brush for a dynamo electric machine |
| IT48546/77A IT1078156B (en) | 1976-03-20 | 1977-03-18 | BRUSH FOR DYNAMOELECTRIC MACHINES AND PROCEDURE TO PRODUCE IT |
| NL7703017A NL7703017A (en) | 1976-03-20 | 1977-03-18 | BRUSH FOR AN ELECTRODYNAMIC MACHINE AND METHOD OF MANUFACTURING IT. |
| AR266905A AR212879A1 (en) | 1976-03-20 | 1977-03-18 | BRUSH FOR A DYNAMOELECTRIC MACHINE |
| FR7708248A FR2344982A1 (en) | 1976-03-20 | 1977-03-18 | SINKED COMPOSITION, AND ITS USE AS A BRUSH FOR A DYNAMO-ELECTRIC MACHINE |
| BR7701671A BR7701671A (en) | 1976-03-20 | 1977-03-18 | BRUSH FOR A DYNAMIC ELECTRIC MACHINE AND PROCESS TO PRODUCE THE SAME |
| DE19772712227 DE2712227A1 (en) | 1976-03-20 | 1977-03-19 | BRUSH FOR DYNAMOELECTRIC MACHINE, DYNAMOELECTRIC MACHINE WITH A BRUSH OF THE TYPE AND METHOD OF MANUFACTURING A BRUSH FOR A DYNAMOELECTRIC MACHINE |
| ES457053A ES457053A1 (en) | 1976-03-20 | 1977-03-21 | Sintered composition |
| JP3055277A JPS52115305A (en) | 1976-03-20 | 1977-03-22 | Dynamoelectriccmachine brush and method of manufacturing it |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB11317/76A GB1568241A (en) | 1976-03-20 | 1976-03-20 | Sintered brush for a dynamo electric machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1568241A true GB1568241A (en) | 1980-05-29 |
Family
ID=9984054
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB11317/76A Expired GB1568241A (en) | 1976-03-20 | 1976-03-20 | Sintered brush for a dynamo electric machine |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB1568241A (en) |
| ZA (1) | ZA771497B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007090435A1 (en) * | 2006-02-08 | 2007-08-16 | Schunk Kohlenstofftechnik Gmbh | Method and device for manufacturing a multilayer compression moulded element |
-
1976
- 1976-03-20 GB GB11317/76A patent/GB1568241A/en not_active Expired
-
1977
- 1977-03-11 ZA ZA00771497A patent/ZA771497B/en unknown
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007090435A1 (en) * | 2006-02-08 | 2007-08-16 | Schunk Kohlenstofftechnik Gmbh | Method and device for manufacturing a multilayer compression moulded element |
| CN102773455A (en) * | 2006-02-08 | 2012-11-14 | 申克碳化技术股份有限公司 | Method for manufacturing a multilayer compression moulded element |
| US8323548B2 (en) | 2006-02-08 | 2012-12-04 | Schunk Kohlerstofftechnik GmbH | Method for manufacturing a multilayer compression moulded element |
| CN102773455B (en) * | 2006-02-08 | 2014-11-19 | 申克碳化技术股份有限公司 | Method for manufacturing a multilayer compression moulded element |
Also Published As
| Publication number | Publication date |
|---|---|
| ZA771497B (en) | 1978-02-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |