DC commutators and carbon brushes for paper mill motors
Paper machines are built around speed control. Every section — wire, press, dryers, calender, reel — has to hold its speed relative to the others, and on a great many machines in India that is still done with DC section drives. DC means commutators and brushes, and commutation quality directly affects whether the section holds speed or the sheet breaks.
We manufacture DC commutators from hard-drawn electrolytic copper segments with mica segment and cone insulation, heat-seasoned under pressure and mirror-turned so the running surface is true. Carbon brushes are made in matched electro-graphite grades with the contact face radiused to the commutator, and slip rings are available for the wound rotor motors on pulpers, refiners and fans.
Where our parts are used in paper industry
- 01
Paper machine DC section drives
Commutators built to the original segment count and diameter, mirror-turned and concentricity checked.
- 02
Dryer, calender and reel drives
Electro-graphite carbon brushes with radiused contact faces that bed in quickly.
- 03
Pulper, refiner and fan motors
Slip ring units and brush gear for the larger wound rotor AC drives.
- 04
Brush rocker assemblies
Brush holders with coil, leaf or roller spring systems to hold pressure through brush life.
What these parts have to survive
- High humidity in the wet end degrades insulation and promotes brush contact film problems
- Continuous running with tightly held speed makes commutation stability critical to sheet quality
- Section drives run for years between overhauls, so commutator surface finish and segment seating must last
- An unplanned stop wastes the sheet in the machine as well as the production time
Made to your sample
Send the worn part or a dimensioned drawing and we manufacture a replacement to the same sizes — no re-machining at your end. Manufacturing in Bulandshahr, Uttar Pradesh since 1995.
Products we supply to paper industry
Paper Industry — common questions
What is a DC commutator and why does it wear?
A commutator is the ring of insulated copper segments on a DC armature that reverses current direction as the machine turns. The carbon brushes sliding across it wear the copper surface and, over time, the mica insulation between segments can stand proud, which causes sparking and accelerates wear on both surfaces.
Can a commutator be replaced without changing the whole armature?
In most cases yes — the commutator is manufactured to the original dimensions and fitted to the existing armature by your rewinding workshop. Send the old commutator or a dimensioned drawing and we build to match.
How do you make sure a new commutator runs true?
The segments are clamped in steel V-rings and heat-seasoned under pressure before final machining, which settles the assembly so it stays tight in service. The running surface is then mirror-turned and checked for concentricity.