Hydraulic jacks serve as the intermediate medium in hydraulic transmission systems, playing the roles of transmitting and converting energy. At the same time, they also perform functions such as lubricating, preventing corrosion, cooling, and flushing among various components within the hydraulic system. The main performance requirements ofhydraulic jacks are as follows:
Appropriate Viscosity and Good Viscosity-Temperature Characteristics Viscosity is the primary factor to be considered when selecting hydraulic oil. Under the same working pressure, if the viscosity is too high, the movement resistance of hydraulic components will increase, the temperature will rise more rapidly, the self-priming ability of the hydraulic pump will decline, and the pipeline pressure drop and power loss will grow. 逆に, if the viscosity is too low, it will augment the volumetric loss of the hydraulic pump, increase the internal leakage of components, thin the oil film of sliding parts, and reduce the supporting capacity.
The significance of viscosity cannot be overstated. In ahydraulic jack システム, when the oil is too viscous, it’s like trying to move through thick honey. The pump has to work extra hard to push the fluid, consuming more energy and generating heat. This heat build-up can damage components over time. On the other hand, if the viscosity is too low, the oil fails to provide proper cushioning and sealing between moving parts. This can lead to leaks, which not only waste hydraulic fluid but also reduce the overall efficiency of the jack.
Good Demulsibility and Hydrolysis Stability During the operation of hydraulic oil, water and condensed water that enter from different sources will come into contact with the hydraulic pump and other components. If the oil has poor demulsibility and hydrolysis stability, it can cause issues such as emulsification, where water and oil mix together in an unruly manner. This can reduce the lubricating ability of the oil and promote corrosion within the system. In industrial environments where humidity is high, or in applications where the hydraulic jack is frequently exposed to water splashes, this property becomes even more critical.
Good Anti-Rust and Anti-Corrosion Properties During its use, hydraulic oil will inevitably come into contact with water, air, and acidic substances generated from oxidation. These factors can cause metals to rust and corrode, thus affecting the normal operation of the hydraulic system. Rust and corrosion can weaken the structural integrity of components like pistons, cylinders, and valves. In a hydraulic jack, even a small amount of corrosion can lead to leaks or reduced performance, potentially endangering the safety of any load it’s lifting.
Good Oxidation Resistance Hydraulic oil also undergoes oxidation during use. The acidic substances produced after oxidation will increase the corrosion of metals, and the generated oil sludge deposits will clog filters and tiny gaps, causing the hydraulic system to malfunction. Oxidation is an inevitable chemical process when the oil is exposed to heat, air, and metal catalysts. したがって, excellent oxidation resistance is essential to extend the lifespan of the hydraulic oil and maintain the performance of the hydraulic jack.
Compatibility with Sealing Materials Due to poor compatibility between hydraulic oil and sealing materials, the sealing materials may expand, soften, or harden, losing their sealing properties. Hence, it is required that the hydraulic oil and the sealing materials be mutually compatible. Different types of sealing materials, such as rubber, elastomers, or plastics, have unique chemical properties. If the hydraulic oil reacts with these materials, it can lead to premature seal failure, allowing hydraulic fluid to leak out and contaminants to seep in.
Good Lubricity (Anti-Wear Property) There are numerous moving parts in a hydraulic system that require lubrication to prevent wear on the surfaces in relative motion. Especially in systems with higher pressures, much higher anti-wear requirements are imposed on the hydraulic oil. In a hydraulic jack that has to bear heavy loads, the surfaces of the pistons and cylinders are under extreme pressure. Adequate lubrication ensures smooth movement, reduces friction, and prolongs the service life of these components.
Good Shear Stability When hydraulic oil passes through the pump, valve throttling ports, and gaps, it undergoes intense shear forces. This causes some large-molecule polymers in the oil, such as the molecules of viscosity improvers, to break into smaller molecules, resulting in a viscosity decrease. Once the viscosity drops to a certain level, the oil becomes unusable. したがって, good shear resistance is necessary. This property is crucial for maintaining the proper fluid behavior of the hydraulic oil under the dynamic conditions of the jack’s operation.
Good Anti-Foaming and Air Release Properties In the hydraulic oil tank, the air bubbles mixed with the oil will circulate along with the oil. This not only reduces the system pressure and worsens the lubrication conditions but also generates abnormal noises and vibrations. さらに, the bubbles increase the contact area between the oil and air, accelerating the oil’s oxidation. したがって, hydraulic oil is required to have good anti-foaming and air release properties. Foaming can make the hydraulic system behave erratically, as the compressible air bubbles disrupt the smooth transfer of hydraulic power. Proper air release allows the system to quickly return to a stable state.
To further expand on these performance requirements, in modern industrial applications, hydraulic jacks are often used in complex and demanding environments. 例えば, in construction sites where they may be exposed to dust, ダート, and extreme temperatures, the hydraulic oil needs to maintain its properties. The viscosity should remain stable across a wide temperature range, from freezing cold mornings to sweltering afternoons. This requires advanced additives in the oil formulation.
加えて, the anti-rust and anti-corrosion properties are not just about protecting the internal components of the jack. In some applications where the jack is used outdoors or in marine environments, it also has to prevent the outer surfaces of the equipment from corroding. This means that the hydraulic oil needs to form a protective film that can withstand continuous exposure to moisture and salt air.
The lubricity aspect is also evolving. With the development of new materials and manufacturing techniques, hydraulic components are becoming more precise. This demands even finer lubrication properties from the hydraulic oil to reduce the slightest amount of wear and ensure the long-term accuracy of the jack’s movement.
さらに, in automated manufacturing plants where hydraulic jacks are integrated into high-speed production lines, the anti-foaming and air release properties are vital for seamless operation. Any air bubbles or foaming can cause micro-second delays in the lifting or lowering of the jack, which can disrupt the entire production process. Regular testing and quality control of the hydraulic oil, as well as continuous research and development to improve these performance characteristics, are essential for the reliable use of hydraulic jacks in diverse industries.
