SUTH 1304 Farm Tractor 130hp With Sunshade

The main difference between hydrostatic steering and power steering lies in the absence of a mechanical steering gear and external mechanical feedback mechanism. There is no mechanical connection between the steering wheel and the guide wheels. Feedback is not achieved through external linkages connected to the guide wheels, but rather through a mechanism within the hydraulic steering gear or a feedback hydraulic cylinder located outside the steering control valve and steering metering pump.

Compared to power steering, hydrostatic steering eliminates the need for a mechanical steering gear, offering advantages such as simple and compact structure, convenient layout, fewer lubrication, maintenance, and adjustment points, and lower cost. Therefore, it is widely used in large and medium-sized wheeled tractors both domestically and internationally. This type of steering system generally has no (or minimal) ground feedback and automatic self-centering, making it suitable for wheeled tractors with speeds not exceeding 40 km/h.

The main disadvantage of this system is the potential for steering failure when hydraulic components malfunction. Therefore, high system reliability is crucial. Additionally, its ground feedback and automatic self-centering performance are relatively poor, although this is less critical for low-speed vehicles.

1) Hydraulic Pump: The hydraulic pump supplies oil to the steering system. Some steering systems have a dedicated hydraulic pump (generally called a steering hydraulic pump), while others share a pump with other hydraulic systems. Steering hydraulic pumps usually include a flow control valve.

2) Hydraulic Actuator (Steering Hydraulic Cylinder or Steering Hydraulic Motor): In hydraulic steering systems, hydraulic cylinders are primarily used as hydraulic actuators; hydraulic motors are rarely used.

3) Control and Regulation Devices: Control and regulation devices include steering control valves, steering metering pumps, hydraulic steering gears (containing steering control valves and steering metering devices), steering valve blocks, flow control valves, pressure reducing valves, priority valves, and feedback hydraulic cylinders, etc., used to regulate the pressure, speed, and direction of the hydraulic flow to achieve various steering system actions, feedback effects, and performance requirements.

4) Auxiliary Devices: These include oil tanks, oil filters, coolers, and oil lines.

5) Working Medium: When the steering system uses its own oil, low-pour-point hydraulic oil N32 is typically used. When sharing oil with other systems, the requirements of each system must be considered. For example, when sharing oil with the transmission system, a dual-purpose hydraulic and transmission oil is generally used.

The hydraulic components in the aforementioned control and auxiliary devices are not all present in every hydrostatic steering system; their selection depends on the system type and performance requirements. For instance, a simple hydrostatic steering system may consist only of a steering hydraulic pump, steering hydraulic cylinder, hydraulic steering gear, oil tank, oil filter, and oil lines.