7.5 ton gantry crane is a good choice for light duty lifting work. It has small size, portable weight, and flexible move, fast speed, high efficiency, very simple to operate and safe to use. For frequent and light lifting work indoor and outdoor, just choose 7.5 ton gantry crane to save energy and cost. Ellsen Group, one of professional crane manufacturers in China, supplies various types of lifting gantries with reliable quality and reasonable price, such as portable truss gantry crane, single girder cantilever gantry crane, double girder industrial crane for coal mine etc. All Ellsen gantry cranes are produced according to strict producing standards and excellent design! Get fantastic deal for 7.5 ton gantry crane from Ellsen!
The property of hydraulic oil decides the performance of the crane
The crane is kind of mechanical device that is composed of cables, chains, pulleys and other components. Lifting chain is an important part of the crane, and the crane has high standards of hydraulic oil performance. The followings are about the requirement details of hydraulic oil.
First is appropriate viscosity. Viscosity shows frictional resistance between the molecules when the oil flows. Too large viscosity can increase transmission resistance in the pipeline, energy loss increases, and the host no-load loss increases, the temperature increases fast and becomes very high. Too small viscosity can’t ensure the good lubrication condition, this can increase the parts weariness and system spill and lead the decrease of pump volume efficiency. The use should be based on the hydraulic system pressure, working temperature, parts travelling speed. High viscosity is suitable for high pressure and high temperature, low viscosity is suitable for high speed.
Second is good viscosity-temperature property. The viscosity-temperature property shows the change degree that oil viscosity up and downs along the temperature change. It is showed as viscosity index. The bigger of viscosity index, the smaller of down degree that oil viscosity increases along the increasing temperature, so that the hydraulic system spill is not serious. The working condition of engineering machinery is general worse, hydraulic oil temperature change along the load and working temperature, viscosity index should be above 90.
Third is good abrasion resistance and lubrication. This can reduce the crane mechanical weariness and prolong the service life.
The fourth is good antioxidant stability. Antioxidant stability shows the ability that low resistance and oxygen content have a chemical reaction when the oil temperature becomes high. Practices show that the oil temperature rises every 10℃, the chemical reaction speed increases by about one time. Hydraulic oil with good antioxidant stability can ensure hydraulic oil normal cycle and not easy become oxidation and metamorphic.
The fifth is good emulsion resistance and rubble resistance. Anti-emulsion refers to the ability that oil mixes with water, after stirring, it becomes emulsion and the water is apart from the mixture. Rubble resistance shows the ability that the oil mixes with air, after stirring, it becomes emulsion, the rubble is apart from the oil. The oil mixed with air or water reduces the oil volume, increase the compressibility. Hydraulic components have slow speed, and easy to make impact and vibration.
The sixth is good shear resistance stability. To improve the oil viscosity index, the oil is put in polymer, such as poly. Its molecular chain is long.
Ellsen 7.5 ton gantry crane for sale
1. Durable material, great quality
2. Professional supplier, factory price
3. Various types, advanced skills
4. High safety, long service life
5. Light weight, simple operation
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