Design and Analysis of the Multifunctional Oil-Injection Equipment for Deep-Sea Hydraulic Systems

Hydraulic systems have been frequently used in deep-sea equipment because of their renowned long service life, stable and reliable performance. However, impurities contained in hydraulic oil, such as solid particles, gas and water, would jeopardize work efficiency of deep-sea hydraulic systems, and in some extreme cases even cause failure of the whole system, resulting in breakdown of crucial deep-sea equipment. Therefore, this paper aims to present a device, multifunctional oil-injection equipment (MOIE), expected to be able to purify hydraulic oil in deep-sea hydraulic systems. Its major functions are to absorb oil, remove impurities and fill oil, among which the removal of water and gas, i.e. dewatering and degassing, is of significance. Theoretical analysis shows that the paper oil filter is able to remove the solid particles in hydraulic oil, and degassing and dewatering of hydraulic oil could be achieved through vacuum filtration and vacuum heating in high-temperature and low-pressure environment. The prototype of the MOIE is designed and manufactured. The results from laboratory experiments indicate that this equipment can effectively remove solid particles, gas and water from hydraulic oil. This study ensures the stability, safety and reliability of the deep-sea hydraulic system by improving the quality of hydraulic oil.