Working Principles and Types of Hydraulic Steering Units
Hydraulic systems provide significant convenience in various fields, from modern agricultural machinery to heavy industrial equipment. One of the most critical components of these systems, hydraulic steering units, plays a vital role in directing vehicles. Steering units transmit the driver’s steering movements to the wheels through hydraulic pressure, allowing for precise vehicle control. However, selecting a suitable steering system for each application and vehicle type is essential for performance and energy efficiency.
Hydrostatic steering is an hydraulic steering system that does not require mechanical steering linkage. In place of mechanical linkage, a steering unit and steering cylinders along with flexible hoses are used. This steering unit is used in industrial vehicles, agricultural tractors, marine ships, constructional equipment and servo-type systems where directional steering is needed.
In this week’s article, we will explore the different working principles and types of hydraulic steering units. We will also provide examples of various features of these steering units available in our product range at HIDROS GROUP. We will particularly focus on open-center and closed-center steering systems, along with their load-reaction and non load-reaction versions.
1)Open-Center Steering Unit: (HKU…/3, 4 Series)
Open-center hydraulic steering units are systems where hydraulic flow circulates continuously. Even when the steering wheel is not in use, hydraulic oil continues to be pumped, resulting in ongoing energy consumption.
The main advantage of these systems is their simple and economical structure. When the steering wheel is turned, hydraulic flow is directed, and the wheels are rotated. They are especially used in heavy machinery and agricultural equipment, as continuous hydraulic flow is necessary in these systems. Open-center steering systems are known for their quick response, but they are not as energy-efficient as closed-center systems.
2)Closed-Center Steering Unit (HKU…/7 Series)
Closed-center hydraulic steering units have a more advanced structure. In these systems, hydraulic flow is cut off when the steering is not in use, allowing for energy savings. Hydraulic pressure is generated only when the steering wheel is turned.
Closed-center steering units are ideal for applications seeking energy efficiency. For example, in construction machinery or large agricultural vehicles, closed-center systems are preferred since the steering is not constantly in use. When the steering wheel is not engaged, the load on the pump decreases, minimizing energy consumption.
Although these systems have a more complex valve structure, they are often preferred due to their energy-saving capabilities and longer lifespan.
3)Load-Reaction Steering Unit
Load-reaction steering units enhance the driver’s feel for the steering by transmitting feedback from the wheels to the steering wheel. They are an ideal solution for vehicles carrying heavy loads or operating in challenging terrain conditions.
In these systems, the resistance and reactive forces from the wheels on the ground are felt by the driver in the steering wheel. This allows the driver to achieve more precise control of the vehicle according to road conditions. Load-reaction steering systems increase safety, especially when maneuvering in tough terrain.
Regardless of whether they are open or closed center, load-reactive systems are preferred for applications that aim to improve the feel of steering control.
4)Non-Reaction Steering Unit
Non-reaction steering systems do not transmit feedback from the wheels to the driver. In these systems, when the steering wheel is turned, the wheels move, but the driver does not feel the resistance from the ground. This provides a smoother and easier steering experience.
Non-reaction systems are generally preferred in applications requiring low precision. Since the feedback from the wheels to the ground is not felt in the steering wheel, they are particularly used in light machinery and low-speed vehicles. While they enhance driving comfort, their lack of feedback may limit their use in challenging road conditions.
If you would like to use steering units with all these features in your systems, you can choose the HKU and HKUS series steering units available in our product range. For more information about these steering units, which come with many additional features, please feel free to contact us. See you in the next blog post!
