Brush springs: precision and contact in every turn

One of the most specialized components in our portfolio is the brush spring, a key element in electrical transfer systems where reliability is critical.

What are brush springs?

Brush springs are springs engineered to maintain constant pressure on a carbon brush against a commutator or slip ring. This pressure is crucial for maintaining continuous and efficient electrical contact, minimizing wear, and prolonging the overall system's lifespan.

They are used in DC motors, generators, alternators, and any system where a rotating part needs to maintain electrical contact.

Common applications

Brush springs are critical components in:

• Electric motors for vehicles, power tools, and home appliances
• Starters and alternators in the automotive industry
• Medical equipment and portable devices, where miniaturization and reliability are essential
• E-mobility systems, including e-scooters, e-bikes, and light electric vehicles
• Aerospace and industrial motors, where long-term performance is non-negotiable

Types of brush springs

Brush springs come in various forms depending on the mechanical behavior and space constraints of the application. At RPK, we specialize in two key types:

1. Spiral torsion springs

Spiral torsion springs are made from flat steel strips wound into coils. They deliver precise and consistent force, making them ideal for compact systems.

Advantages:

• Highly controlled contact force
• Excellent dimensional stability
• Easy integration into tight spaces

2. Twin springs

Twin springs are composed of two flat bands wound in parallel, working together to handle higher loads and resist fatigue.

Advantages:

• Greater durability under repetitive stress
• Balanced pressure distribution
• Superior dynamic behavior

Benefits of brush springs

Brush springs offer multiple performance advantages in demanding electromechanical systems:

• Reduce brush wear, extending maintenance intervals
• Minimize arcing and sparking, improving safety and system efficiency
• Increase motor lifespan through stable electrical contact
• Ensure consistent torque and smooth operation, even under variable loads
• Allow for longer brushes and larger commutators, optimizing power transfer
• Maintain constant force as the brush wears, ensuring reliable contact and preventing premature failure

Custom design and engineering

At RPK Group, we work side-by-side with our clients to develop custom brush spring solutions, optimizing materials, geometries, and heat treatments to ensure top performance. Our expertise in precision spring manufacturing enables us to meet the most demanding market requirements.