Hydraulic steering systems

Hydraulic steering systems use hydraulic fluid pressure to transmit the steering forces from the steering wheel to the wheels. This allows precise and responsive steering with minimal driver effort.

The main components are:

• Steering units (Orbitrol/CSUS)
• Steering cylinders
• Valves
• Hydraulic pump
• If required, a priority valve

In hydrostatic systems, a fully hydraulic variant, there is no longer a mechanical connection between the steering wheel and the wheels; the entire torque is transmitted solely via hydraulic fluid.

Hydraulic steering systems are mainly used in heavy or slow-moving vehicles where high steering performance and comfort are required:

• Commercial vehicles (e.g. trucks, forklifts)
• Construction machinery (e.g. excavators, wheel loaders)
• Agricultural machinery (e.g. tractors, combine harvesters)
• Ships and boats

They enable small turning circles, simplified installation and retrofitting, improve safety and optimize fuel consumption.

Open Center – Non Load Reaction: The hydraulic fluid flows openly from the pump back to the tank when the steering wheel is in neutral position. This is energy-saving at idle and typical for fixed displacement pumps. "Non Load Reaction" means that external forces (e.g. shocks) are not transmitted to the steering wheel in neutral, because the steering unit closes both connections of the steering cylinder.

Closed Center – Load Sensing: A more efficient system with a variable displacement pump that adjusts flow and pressure according to demand. In neutral position the oil flow remains closed, and the pump only works when needed. The system detects the pressure and flow requirements of the consumers and supplies only the necessary amount of oil – energy-saving, low-wear and with less heat generation.

Modern hydraulic steering systems, especially CSUS types, can include the following valve functions:

• Pressure relief valves (overpressure protection)
• Shock valves (protection against pressure peaks)
• Make-up valves (prevention of cavitation)
• Check valves (ensuring flow direction)

• Wide range and individual configuration: Broader portfolio and customer-specific adaptations compared to OEM standard solutions from Danfoss, ZF, John Deere, Fendt or Case.
• Comprehensive consulting: Individual customer advice for optimal solutions.
• Attractive pricing: Often more affordable than original parts from established brands.
• Custom manufacturing: Possibility of adaptation and special designs, especially for retrofits and spare parts.
• High quality according to EU standards: Hydromot ensures that the components are comparable in quality to brands like Danfoss, ZF or Deutz.

Priority valves ensure that the steering always receives sufficient hydraulic fluid, even when other consumers are operating at the same time. This is an important safety function, as steering always has absolute priority.

• Check and replace hydraulic fluid
• Inspect seals and valves (leakage check)
• Regular functional testing of the steering unit

The selection depends on various criteria:

• Vehicle type and operating conditions: Different requirements for agricultural machinery (Fendt, Deutz), construction machinery (Case, Hanomag) or commercial vehicles (John Deere, ZF).
• System design: Choice between Open Center or Closed Center as well as load-sensing requirements.
• Safety functions: Need for emergency steering, priority valves or special valve types.