A Wonder Material Called Carbon
TCP specializes in custom solutions for particular electrical motor application. Our carbon brushes are engineered to provide maximum performance and long life, with minimal maintenance and downtime. With years of experience, expertise in design and manufacturing, and understanding a wide variety of brush applications, we can customize your product to best fit and function in the application.
The carbon brush is a critical component of an electric motor and can be a maintenance headache if not designed properly. Applying the right brush for the application will not only extend the brush life, but also the commutator or ring surface, thus avoiding costly motor repair.
Taking advantage of the self-lubrication and chemical and heat resistance features of carbon, our mechanical carbon grades are used for sliding parts in high temperature environments where metals cannot be used as well as for submersion in chemicals and in fields where lubricated parts cannot be used. Already, our carbon seals, rings, bearings and vanes are widely used and highly evaluated in a broad range of industries.
Our broad range of carbon brushes, tablets & blocks includes following grades:
Resin Bonded
Powdered natural or artificial graphite is mixed with a thermo-setting resin.The mix is then pressed and polymerized at a suitable temperature.
Main Characteristics
Carbon brushes with high to very high electrical resistance, contact drop, electrical loss,and mechanical strength, which have very good commutating and cleaning properties.They can also work at very low current densities.Main Applications
- AC Schrage-type commutator motors
- Medium-speed DC machines at medium voltage
Operating Limitations
- Resin-bonded grades should not be used at higher than rated current
- Brush current density: 10A/cm2 continuous
- Admissible peripheral speed: 40 m/s (131 ft/s)
Metal Graphite and Silver Graphite
Powdered natural or artificial graphite is mixed with a thermo-setting resin, copperpowder, and/or other metal powders. The mix is then pressed and polymerizedat a suitable temperature in an inert atmosphere.
Main Characteristics
Dense to very dense carbon brushes with low friction and very low contact drop, therefore operating with very low losses and high currents.Copper-based brush grades
Main Applications
- Low-speed, low voltage DC machines
- Medium-speed, highly-loaded AC asynchronous machines (wind turbine generators)
- Medium-speed AC synchronous motors slip rings
- High current collection systems (electrolytic treatment lines, wire annealers, galvanizinglines ...)
- Low-voltage current collection (military, medical, paramedical, signal ... )
- Special machines
- Slip ring assemblies in rotary joints
Operating Limitations
- Current density:
- 10 to 30 A / cm 2 (75 to 200 A/in 2 ) under steady conditions
- Up to 100 A / cm 2 (660 A/in 2 ) for peak loads, depending on metal content
- Peripheral speed: up to 35 m/s (115 ft/s), depending on metal content
Silver-based brush grades
Silver grades have a higher conductivity than copper grades and form a special low resistance film due to the conductivity of silver oxide. Silver grades can also transfer low voltage current signals without degradation.Main Applications
- Signal current transmission (thermocouples, thermometric sensors, regulation...)
- Pulse transmission to rotating devices (radar, prospection..)
- Tachometer generators
- Aerospace and space applications
- Shaft grounding in a dual-grade construction
Operating Limitations
- Current density up to 50 A/cm 2 (440 A/in 2 ).
- Peripheral speed: up to 25 m/s (82 ft/s)
Carbon graphite
They are made from a mixture of coke and graphite powders, agglomerated with pitch or resin. This powder is molded into blocks which are baked at high temperature to convert the binder into coke. These materials are not graphitized.
Main Characteristics
Carbographitic brushes commutate well due to their high resistance and provide good polishing action, while maintaining moderate contact drop. As a result of their high temperature treatment, carbographitic brushes can withstand both high temperatures and variable loads.Main Applications
- Machines with an older design, mostly characterized by a slow speed, lack of interpoles,generally operating at low voltage
- Modern small machines, operating with permanent magnets, servomotors, and universalmotors
- Low voltage battery powered motors
Operating Limitations
- Current density in the brushes: 8 to 16A /cm 2 (50 to 100 A/in 2) depending on the application
- Maximum peripheral speed: 25 m/s (82 ft/s)
Natural Graphite
The main ingredients are purified natural graphite and artificial graphite, mixed with additives, agglomerated with appropriate binders, and treated at a high temperature to carbonize the binder.
Main Characteristics
LFC brushes have a low Shore hardness with excellent shock absorbing properties. This allows them to work in applications where other materials would fail. They excel at high peripheral speeds which amplify the mechanical stresses associated with friction, vibration, air flow, run out, and heat.Main Applications
- Steel and stainless steel slip rings for synchronous machines.
Operating Limitations
- Current density in the carbon brushes: 10 to 13 A/cm 2 (71 to 84 A/in 2 )
- Maximum peripheral speed: up to 90 m/s (295 ft/s)
Electrographite
Electrographitic materials are carbographitic materials that are graphitized at temperatures in excess of 2,500 oC in order to transform basic amorphous carboninto artificial graphite.
Main Characteristics
Electrographitic brushes have a medium contact drop and low to medium friction coefficient, and therefore have low electrical loss, particularly suited to high peripheral speeds ( ≤ 50 m/s). The graphitization process yields a high strength, low resistance material, particularly resistant to high temperatures.Main Applications
- All DC stationary or traction industrial machines, operating with low, medium or high voltage and constant or variable loads. They are also found on AC synchronous and asynchronous slip ring applications.
Operating Limitations
- Current density in the brushes:
- 8 to 12 A/cm2 (50 to 75 A/in 2 ) under steady conditions
- 20 to 25 A/cm2 (130 to 160 A/in 2 ) for peak loads
- Maximum peripheral speed: 50 m/s (154 ft/s).
Application
Our carbon brushes serve wide range of industries including following:
Examples of Automotive Brushes:- Click here
Users of our Carbon brushes
Our Carbon brushes are engineered to meet broad range of applications including following key sectors.
Product Catalogue
Product Specification and Catalogue
TCP Automobile Carbon Brushes
TCP MG Tablets
TCP MG Blocks
TCP MG Auto Tablets
TCP - Specifications of MG Grades
Mechanical Carbon Products
Taking advantage of the self-lubrication and chemical and heat resistance features of carbon, our mechanical carbon grades are used for sliding parts in high temperature environments where metals cannot be used as well as for submersion in chemicals and in fields where lubricated parts cannot be used. Already, our carbon seals, rings, bearings and vanes are widely used and highly evaluated in a broad range of industries.
Seal Rings
Carbon sealing rings are used as the wear face of the most mechanical seals for the sealing of fluids in all industries. Seals are made in solid rings, split rings, and segmental rings for use in both liquid and dry running applications. Applications include Process pumps, Rotary steam joints, Seals for agitators and autoclaves, Chemical pumps, Cold and Warm water pumps, Corrosive liquid pumps.
Gland Rings
These rings are highly specialized products and used as shaft seals in fans, water and steam turbine installations, nuclear power stations and hydroelectric schemes. Gland rings are of two types Tenon types and Wedge types.
Bearings
This product offering includes Stocker Bearings, Axial Bearings, Bush Bearings, Clutch Bearings. Carbon is self-lubricating and has a low coefficient of friction at high and low temperatures. Its use as a bearing material is extensive when a conventional lubricant is not possible and also where the performance of other lubrication is poor. There are other properties which give it unique and distinctive advantages for bearings. Applications include Submersible pump motor, Vertical centrifugal pump, Aircraft fuel pump
Steam Joints
These joints connect a flow of liquid or vapour from a stationary supply piped to a rotating machine part, such as a roll, dryer or cylinder. Rotary pressure joints fitted with carbon rings are widely used in the paper industry. They also find application in the textile, plastics, rubber, petro chemical, food and other industries handling liquids and vapours up to temperatures of 350 oC.
Carbon Vanes
Carbon vanes are self-lubricating and are ideal for pumps, handling liquids such as petrol which has poor lubricating properties. Vanes can also operate in unlubricated compressors to deliver air or gas uncontaminated by lubricating oil or greases, in which carbon gives a fine polish to cylinder wall which reduces the wear rate of the vane after bedding almost negligible proportions. Carbon vanes are chemically inert and non-toxic and cannot contaminate the liquid or gas being handled. They can safely be used in food-processing equipment and in other fields where purity is essential. Carbon vanes are totally unaffected by water (pure or salt), most acids, alkalis or oil solvents such as petrol or paraffin. In these conditions, the liquid can reduce friction and wear by providing lubrication between vane and rotor slots and vane top and cylinder wall. One of the most important requirements for vane materials is high mechanical strength. Carbon vanes meet this requirement. Their strength is indicated by the pressure regularly handled, which ranges from 3.2 kgf/cm2 down to high vacuum conditions, with peripheral speeds up to 12.7 m/sec.
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