Electric Power Recirculating Ball Steering (eRCB) for Commercial Vehicles
As commercial vehicles continue to evolve toward electrification, intelligent control, and system integration, power steering systems are undergoing a fundamental transition from hydraulics to fully electric solutions.
The development of commercial vehicle power steering technology has progressed through four key stages: Mechanical steering, Hydraulic power steering (HPS), Electro-hydraulic steering (EHPS), and Fully electric steering systems, represented by Electric Power Recirculating Ball Steering (eRCB).
For electric and hybrid commercial vehicles—especially light- and medium-duty platforms—eRCB offers a practical balance between high load capability, energy efficiency, and electronic controllability, while retaining the robustness of traditional recirculating ball steering mechanisms.
What is the Electric Power Recirculating Ball Steering (eRCB) System?
The Electric Power Recirculating Ball Steering (eRCB) system is an electrically assisted steering solution based on a traditional recirculating ball steering gear, enhanced with an integrated electric motor and reduction mechanism at the input shaft.
Unlike purely mechanical systems, eRCB actively generates steering assist torque through motor control rather than hydraulic pressure. The system processes:
- Steering torque signals
- Vehicle speed signals
- Active control commands
Based on these inputs, the controller drives the electric motor to deliver adaptive steering assistance and enable advanced steering functions, while maintaining the durability and load-bearing advantages required by commercial vehicles.
How Does the Electric Power Recirculating Ball Steering Work?
When the driver turns the steering wheel:
- Torque Sensing
A torque sensor detects the steering input via a torsion bar inside the steering shaft. As the driver applies force, the torsion bar twists, and the twist angle is measured.
The detected torque is directly proportional to the torsion bar’s angular deformation. - Vehicle Speed Input
A vehicle speed sensor sends speed signals (typically square-wave signals) to the steering controller. - Control and Motor Actuation
The controller processes both torque and speed signals using a predefined assist characteristic model.
It then regulates the motor current accordingly. - Torque Amplification and Assistance
The motor output torque is amplified through the reduction mechanism and applied directly to the steering gear, assisting the driver’s steering input.
This closed-loop control architecture enables speed-sensitive assistance, stable high-speed handling, and precise low-speed maneuverability.
Key Advantages of Electric Power Recirculating Ball Steering Systems
Compared with traditional hydraulic power steering solutions, eRCB offers clear system-level advantages for commercial vehicles:
1. Lower System Procurement Cost for Electric Vehicles
Electric vehicles using hydraulic steering require an additional electric motor and controller to replace the engine-driven hydraulic pump.
This increases both system complexity and cost. By contrast, eRCB integrates assistance directly into the steering gear, resulting in lower overall system cost.
2. Fewer Components and Reduced System Weight
Hydraulic steering systems require multiple components, including hydraulic pumps, motors, and controllers, and oil hoses and reservoirs. The eRCB system eliminates these components through full electrical integration, reducing assembly complexity. Overall system weight can be reduced by approximately 50%, improving vehicle packaging flexibility and safety.
3. Extended Driving Range and Improved Energy Efficiency
Hydraulic steering systems typically require a continuously operating motor with power ratings of 2 kW or higher, leading to constant energy consumption.
In contrast, eRCB operates on 12V or 24V electrical systems; typical motor power demand is around 400 W; energy is consumed only during steering events.
Vehicle tests show that eRCB can improve driving range by over 25% compared to hydraulic steering systems.
4. Adaptive Steering Feel and High-Speed Stability
The eRCB system dynamically adjusts steering assistance based on vehicle speed, light, and responsive steering at low speeds; firm and stable steering feel at high speeds. This improves vehicle controllability, driver comfort, and operational safety—especially for commercial vehicles operating under varying load conditions.
5. No Hydraulic Oil, No Leakage Risk
By eliminating hydraulic fluid, eRCB removes the risk of oil leakage, reduces environmental impact, and simplifies maintenance and servicing.
6. High Reliability and Maintenance-Free Operation
The fully electric design ensures high system reliability, stable performance in low-temperature environments, and maintenance-free operation over the vehicle lifecycle.
7. Broad Vehicle Applicability
The eRCB system is suitable for internal combustion engine vehicles, hybrid vehicles, and pure electric commercial vehicles. It is particularly well-suited for light- and medium-duty electric platforms requiring high steering loads and electronic controllability.
Brogen's eRCB Solutions
We provide electric power recirculating ball steering (eRCB) systems designed specifically for commercial vehicle applications, with a focus on functional safety, system integration, and future-ready electronic architectures.
System Functions
- Speed-sensitive power assistance
- Active return
- Dampling compensation function
- Friction compensation function
- Rack end protection function
- Inertia compensation function
- Temperature management
- Motor thermal protection
System Advantages
- Provides eRCB products supporting L2 autonomous driving
- Configurable interfaces, compatible with various TAS sensor types
- Supports CAN/CANFD interface
- Supports Cybersecutiry hardware encryption
- Supports OTA upgrades
Example System Configuration
*Specifications are for reference only. For specific vehicle platforms, please contact us to discuss requirements with our engineering team.
ITEM |
Parameters |
|---|---|
Steering Gear Type
|
Electricc Power Recirculating Ball Steering Gear
|
Steering Operation Mode
|
Manned Drivinng
|
Worm Shaft Rotation Direction
|
Left-hand Rotation
|
Maximum Steering Gear Output Torque
|
1500 N.m
|
EPS Functions
|
Speed-sensitive power assist; active return-to-center
|
Contact Us
Get in touch with us by sending us an email, using the Whatsapp number below, or filling in the form below. We usually reply within 2 business days.
Email: contact@brogenevsolution.com
Respond within 1 business day
Whatsapp: +8619352173376
Business hours: 9 am to 6 pm, GMT+8, Mon. to Fri.
LinkedIn channel
Follow us for regular updates >
YouTube channel
Ev systems introduction & industry insights >
