Brush Assemblies

//Brush Assemblies
Brush Assemblies2017-04-06T18:30:29+00:00

INTRODUCTION
Fabricast offers a complete line of silver graphite leaf and plunger brushes. These assemblies can be used to replace worn brushes on Fabricast slip rings or for other applications on which the customer feels they would be applicable. Our engineers will specify the best brush grade for both Fabricast built slip rings and for customer applications.

BRUSH CONTACT MATERIAL

Download printable PDF of this page
The following chart gives some basic information on the most common brush contact materials.
Grade NumberCompositionRecommended
Surface Speed
Carrying Capacity
FAG 18080% Silver
20% Graphite
Up to 3500
feet per minute
250 amps per
square inch
FAG 180A80% Silver
20% Graphite
plus MoS2
Up to 3500
feet per minute
250 amps per
square inch
FAG 15050% Silver
50% Graphite
Up to 6000
feet per minute
100 amps per
square inch
FAG 150A50% Silver
50% Graphite
plus MoS2
Up to 6000
feet per minute
100 amps per
square inch
FAG 19393% Silver
7% Graphite
Up to 250
feet per minute
300 amps per
square inch

Fabricast grade FAG180 is the low noise level grade used for all standard assemblies. In general, a noise level of approximately 1 microvolt for each milliampere of current flow can be accomplished depending on the speed of the unit and quantity of brushes per ring.

Fabricast grade FAG150 is the highest surface speed grade: however, noise levels are slightly higher than FAG180. Brush life is approximately twice that of FAG180. It is recommended when brush life is critical and/or surface speed is high. Low noise can be achieved with multiple contacts per ring.

Fabricast grade FAG193 has highest current carrying capacity; however, it is limited to a surface speed of 250 ft. per minute.

Fabricast grades FAG180A and FAG150A contain molybdenum disulfide in addition to silver and graphite. This additive is required for operation in altitude, vacuum, and inert environments. Other characteristics remain the same.

PLUNGER TYPE BRUSH ASSEMBLIES Download printable PDF of this page
Plunger type brush assemblies consist of a brass holder with cap, a copper or BeCu buss assembly, and a spring loaded silver graphite plunger brush. Both holder and buss are tin plated. Brush holders are most commonly press fit into a dielectric brush block or soldered/brazed to a buss which is then bolted to the brush block.

brush-1

2.5 AMP CAPACITY • 3/32” SQUAREbrush-1

4 AMP CAPACITY • 1/8” SQUARE
brush-2
10 AMP CAPACITY • 3/16” X 1/4” RECTANGULAR

brush-3 brush-3
25 AMP CAPACITY • 1/4” X 1/2” RECTANGULAR
brush-4 brush-4
50 AMP CAPACITY • TWO EACH 1/4” X 1/2” RECTANGULAR
brush-5

The following chart shows the different plunger brush part numbers for specific brush sizes and brush grades. Download printable PDF of this page

Plunger Brush Part Number Chart
Brush SizeBrush Grade
 FAG 180FAG 150 FAG 180AFAG 150AFAG 193
3/32″ Square1072-11072-51072-111072-101072-14
1/8″ Square1072-21072-61072-131072-121072-15
3/16″ x 1/4″1913-11913-21913-31913-41913-5
*1/4″ x 1/2″10920031092003-311092003-291092003-271092003-25
**1/4″ x 1/2″1991-11991-21991-31991-41991-5

* For use with brush holder P/N 1092006
** For use with brush holder P/N 1092012

For complete information on the different plunger brushes and holders available please download relevant catalog pages or request a Fabricast catalog by phone, Email, or by completing the Request For More Information Form.

LEAF TYPE BRUSH ASSEMBLIES Download printable PDF of this page

Leaf springs for Fabricast leaf type brush assemblies are made of beryllium copper alloy #25. The leaf springs are heat treated and tin plated. The silver graphite brush contacts are soldered onto the leaf springs.

2 AMP CAPACITY • SINGLE BRUSH
BRUSH .040 WIDE • BRUSH MATERIAL – FAG 180 (80% AG – 20% C) • LEAF MATERIAL – BECU
Leaf-Brushes-1

5 AMP CAPACITY • DOUBLE BRUSH
BRUSH .040 WIDE • BRUSH MATERIAL – FAG 180 (80% AG – 20% C) • LEAF MATERIAL – BECU
Leaf-Brushes-2

Leaf-Brushes-3

5 AMP CAPACITY • SINGLE BRUSH
BRUSH .090 WIDE • BRUSH MATERIAL – FAG 180 (80% AG – 20% C) • LEAF MATERIAL – BECU

Leaf-Brushes-4

OPTION: Opposite hand assemblies available. Optional brush location shown in phantom.

5 AMP CAPACITY • SINGLE BRUSH
BRUSH .090 WIDE • BRUSH MATERIAL – FAG 180
(80% AG – 20% C) • LEAF MATERIAL – BECU
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10 AMP CAPACITY • DOUBLE BRUSH
BRUSH .090 WIDE • BRUSH MATERIAL – FAG 180
(80% AG – 20% C) • LEAF MATERIAL – BECU
Leaf-Brushes-5

All leaf type assemblies illustrated above are specified with FAG 180 brush contact material. For description of optional brush contact materials see catalog page 14.

Brush Part Coding

Determination of Angle “X”:
Angle “X” will be supplied by our engineering department for all Fabricast slip ring replacement brushes. For other applications specify angle “X” so that in free state BeCu leaf spring (without brush contact material) would just touch ring surface. This method defines a good starting point for proper brush pressure in most applications. NOTE: Angle “x” does not apply to types 1799, 1120051, and 8115.

For complete information on the different leaf brushes available please download relevant catalog pages or request a Fabricast catalog by phone, Email, or by completing the Request For More Information Form.