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Recirculating Ball (RCB) with Integrated Hydraulic Power Steering

The product was developed jointly with ZF Lenksysteme GmbH for the LADA 4x4 (NIVA) project. Patented design. Rulevye Systemy Ltd. is a system supplier of all elements of the RCB. The production of hydraulic power steering conforms to the requirements of IATF 16949:2016 and GM QSB standards.

LADA NIVA LEGENDSerial production
LADA NIVA TRAVELSerial production
Special vehicles
Special vehiclesSerial production

This project involved engineering development of the hydraulic power steering system as follows:

  • Development, validation and fine-tuning of the RCB steering system.
  • Drawing up technical requirements for components/modules of the system.
  • Research, selection, and management of Tier 2 and Tier 3 suppliers.
  • Outsourcing management in the field of product/process development and validation.
  • The production cycle of Rulevye Systemy Ltd. includes:

    • Machining of body parts (housing/cover) made from high-strength cast iron ВЧ50 at MAZAK CNC machining centers.
    • Assembly of the steering gear, subsequent testing and registering of key characteristics on specialized ZF test benches.
    • Painting of the RCB using enamel with increased corrosion resistance.
    • Assembly of the RCB pump with bracket and pulley.
    • Manufacturing of assembly kit parts (pulleys, bolts, spacers).

The key feature of the design is that the force generated by the hydraulic cylinder is proportional to the resistance force of the driven wheels to turn. In other words, this system assists the driver just so: they can easily turn the steering wheel while maintaining their road sense.


The main components of a car RCB system:

  • Recirculating Ball (RCB) with Integrated Hydraulic Power Steering.
  • Vane oil pump + bracket assembly.
  • Oil tank.
  • High-pressure and low-pressure hoses.

Technical parameters:

  Number of rotations of the steering wheel 2,9
  Gear ratio of the rack and screw pair 14,5
  Operating pressure, MPa 9,6 – 10,4
  Pump capacity 6 L/min
  Maximum oil temperature 120 С
  Total oil volume in the system 1 L
  Oil tank capacity 0,4 L

As part of the research at Rulevye Systemy Ltd., at the request of automakers of high and light commercial vehicles, the following works were performed:

  • Engineering development of a hydraulic power steering gear together with partners.
  • Development of the technology for machining of the steering gear body parts (housing/cover) made from high-strength cast iron EN-GJS-500-7 (ВЧ50) for the GAZ/KAMAZ vehicles with the purchase of the necessary equipment.
  • Validation of the machining process.
  • Manufacturing of prototypes of body parts from workpieces on existing equipment.
  • Experimental assembly of steering gears using body parts manufactured by Rulevye Systemy Ltd.

To assess the possibility of serial production of RCB, Rulevye Systemy Ltd. researched the options of purchasing components for steering gears from alternative suppliers in China.

Technical parameters of manufactured prototypes

  Number of rotations of the steering wheel 4,8 6,2
  Gear ratio of the rack and screw pair 19,6 26,0
  Operating pressure, MPa 12 16
  Pump capacity 8 L/min 16 L/min
  Maximum oil temperature 120 С 120 С