RU1809725C - Composition to manufacture current collectors - Google Patents

Abstract

FIELD: electrical engineering. SUBSTANCE: composition including electric graphite, phenolformaldehyde resin, aluminium is injected with calcined coke and zinc stearate with following proportion of components, per cent by mass: electric graphite 67.0-75.0; phenolformaldehyde resin 11.0-22.0; calcined coke 5.0-12.0, zinc stearate 0.5-2.0, aluminium being the balance. It is more advantageous inject calcined coke and zinc stearate with proportion (6-10): 1. EFFECT: expanded application field in high-speed electric motors. 1 tbl

Description

 The invention relates to electrical engineering and relates to a composition for the manufacture of current collectors, for example, inserts for current collectors of electric rolling stock, as well as brushes of electric machines.

 The aim of the invention is to improve the operational characteristics of current collectors by increasing the toughness of the material, reducing the abrasive effect of the insert on the contact wire, increasing wear resistance when working in wet conditions.

The invention consists in the following. Known composition for the manufacture of current collectors containing electrographite (high-purity graphite powder with an ash content of not more than 0.3%), phenol-formaldehyde resin, aluminum, additionally contains calcined coke and zinc stearate in the following ratio, wt.%: Electrographite 67-75 Coke calcined 5-12
Phenol formaldehyde resin 11-20 Zinc stearate 0.5-2.0 Aluminum Else
Calcined coke, introduced into the composition, increases the adhesive ability of the binder to the filler, increases the yield of solid residue, strengthens the binder-filler system, thereby increasing the toughness of the material (i.e., the ability of the material to withstand shock loads). In addition, coke particles, unlike silicon carbide, are well distributed in the mass of graphite powder and contribute to uniform cleaning of the excess carbon film on the contact wire, thereby eliminating the uneven wear of the wire. The introduction of coke in the composition reduces its plastic properties. Zinc stearate restores the plasticity of the composition, allows to obtain a material with high density during pressing, to reduce its moisture capacity.

 Inserts in wet weather are much more efficient. In this case, it is important to observe the amount of powders introduced.

 The proposed technical solution allows to obtain more wear-resistant brushes by increasing the toughness of the material used for electric motors with high speeds.

 PRI me R 1 (prototype). 79.7 wt.% Electrographite (TU 48-20-54-84) was mixed in a Z-shaped mixer for 10 minutes, then 3 wt. % aluminum (GOST 60-58-73) with a particle diameter of less than 71 microns and 0.3 wt.% granular silicon carbide (OST6-441-78). The mass was stirred for 50 minutes.

 17 wt% of a binder — phenol formaldehyde resin SPFO11L — was introduced into the averaged powder mixture and mixed for 40 min.

The mass discharged from the mixer and milled on a mill BW 800E 3-fold at a temperature of 135-145 ^C. The rolls Provaltsovannuyu mass was ground in a mill DM-300, sieved through mesh 045. From the press powder was pressed at 63 ton press at a pressure 900 kgf / ^cm2, a temperature of 175-185 ^{° C} and 1.5 minutes exposure insert size 29h88h17,5 mm.

From the molding powder and compressed on a 63-ton press at a specific pressure of 1200 kgf / cm ^2, a temperature of 175-175 ^{° C} and holding for 1.5 minutes blocks of 29h88h25 mm. From the block by means of machining, brushes of 8x12.5x20 mm in size were prepared.

PRI me R 2. 71 wt.% Electrographite (TU 48-20-54-84) and 8 wt.% Coke calcined (TU 14-7-80-86), crushed and sieved through a sieve 07, was mixed in Z-shaped mixer for 30 minutes To the averaged filler thus obtained was added 17 wt% of a binder — phenol-formaldehyde resin of the SFPO11 brand (TU 18-694-80) —and was again mixed for 40 minutes. The mass discharged from the mixer and milled on a mill BW 800E 3-fold at a temperature of ^about 135-145 rolls.

 The rolled mass was ground in a DM-300 mill, sieved through a 045 mesh. 3 wt.% Aluminum powder (GOST 60-58-73) and 1 wt.% Zinc stearate (TU 6-09-4473-77) were introduced into the obtained powder, the ratio of coke to zinc stearate is 8: 1.

The mixture was stirred for 40 minutes in a Z-shaped mixer and discharged. From the resulting powder was pressed at 63 ton press at a pressure of 900 kgf / cm ^2, a temperature of 175-185 ^{° C} and 1.5 minutes exposure insert size 28h88h17,5 mm. From the same powder size compressed blocks 29h88h25 mm by 63-ton press at a specific pressure of 1200 kgf / cm ^2, a temperature of 175-185 ^{° C} for 1.5 min. From the blocks, by machining, brushes of 8x12.5x20 mm in size were prepared.

PRI me R 3. 71 wt.% Electrographite (TU 14-48-20-54-84) and 8 wt.% Coke calcined (TU 14-7-80-86), crushed and sieved through a sieve 07 were mixed in a Z-shaped mixer for 30 minutes A binder — phenol-formaldehyde resin of the SF-342 grade — in an amount of 17 wt.% Was added to the filler averaged in this way and mixed again for 40 minutes. The mass discharged from the mixer and milled on a mill BW 800E 3-fold at a temperature of 115-125 ^C. The rolls Provaltsovannuyu mass was ground in a mill DM-300, sieved through the mesh 045. The resulting powder was added 3 wt.% Of aluminum powder (GOST 60 -58-73) and 1 wt.% Zinc stearate (TU 6-09-4473-77), the ratio of coke to zinc stearate is 8: 1). The mixture was stirred for 40 minutes in a Z-shaped mixer and discharged. From the resulting powder was pressed at 63 ton press at a pressure of 900 kgf / cm ^2, a temperature of 175-185 ^{° C} and 1.5 minutes exposure insert size 28h88h17,5 mm. Inserts C105 fired in a furnace at a temperature of 900 ^{° C} in a nitrogen environment.

From the molding powder compacted blocks razmepom 29h88h25 mm by 63-ton press at a specific pressure of 1200 kgf / cm ^2, a temperature of 175-185 ^{° C} and holding for 1.5 minutes. Blocks fired in a furnace at temperature 105 C 900 ^C in a nitrogen environment. From the blocks, by machining, brushes of 8x12.5x20 mm in size were prepared.

 PRI me R s 4-11. By the technological process described in Example 2, compositions were made with limit and transcendental values of the components and ratios of coke and zinc stearate, from which inserts and brushes of electric machines were made.

The inserts made according to examples 1-11 were tested for impact strength in the amount of destructive force on a tensile testing machine R-5 and subjected to operational tests on the route with the following characteristics:
Contact wire brand MF-85 Suspension type Chain
Intersection number
with tram lines 12
Intersection number
trolleybus lines 5
Contact network length, km 9.72
Humidity 80% at a temperature of 20-22 ^o C.

 The brushes of electric machines made according to examples 1-11 were tested on a high-speed short-circuited collector KZK-95. The test results of current collectors (trolleybus inserts and brushes of electric machines) are presented in the table.

 As follows from the analysis of the test results of current collectors obtained from the known (prototype) and the proposed composition, the proposed technical solution can significantly improve the operational characteristics of the products.

 The introduction of calcined coke and zinc stearate in the composition makes it possible to increase the toughness by a factor of 1.4-1.6 (examples 2-7, see data on the breaking strength) of the composition, which significantly affects the resource of the fracture inserts: the resource increases by 2 5-3 times. The wear of the inserts per 100 km is reduced by 1.5-1.7 times, the wear of the contact wire is 0.

 The test results of this material as a brush on a high-speed manifold reveal its greater wear resistance, lower friction coefficient, less transient voltage drop, which is especially important when operating high-speed engines used in household appliances.

 Thus, the additional content in the coke composition of calcined and zinc stearate in a certain ratio between them makes it possible to significantly improve the operational characteristics of current collectors, especially when working in wet conditions. Failure to comply with these ratios leads to a violation of the plasticity of the composition, its formability, to a violation of the operating mode due to the formation of excess (or vice versa insufficient) carbon film on the contact wire (collector). This is confirmed by the data obtained on the wear of the insert per 100 kilometers and the destruction resource (examples 9, 10 and 11).

Claims (1)

COMPOSITION FOR MANUFACTURE OF CURTAIN TOWERS, containing electrographite, phenol-formaldehyde resin, aluminum, characterized in that, in order to improve performance, it additionally contains calcined coke and zinc stearate in the following ratio, wt.%:
Electrographite - 67.0 - 75.0
Phenol formaldehyde resin - 11.0 - 20.0
Calcined Coke - 5.0 - 12.0
Zinc stearate - 0.5 - 2.0
Aluminum - Else

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