CN-122014983-A - Liquid metal lubrication system, monitoring method and mechanical equipment

CN122014983ACN 122014983 ACN122014983 ACN 122014983ACN-122014983-A

Abstract

The invention discloses a liquid metal lubrication system, a monitoring method and mechanical equipment, and relates to the technical field of engine lubrication. The liquid metal lubrication system comprises a bearing assembly and a liquid metal lubricant, wherein the liquid metal lubricant is filled in a gap of the bearing assembly, the liquid metal lubricant contains rare earth elements, the bearing assembly comprises a retainer, the retainer is arranged in a roller path and used for separating and guiding rolling bodies, the interior of the retainer is provided with a gradient pore structure, the porosity of the gradient pore structure continuously decreases along the direction from an inner ring to an outer ring of the bearing, and the gradient pore structure is used for driving the liquid metal lubricant to flow back from an outer side area with low porosity to an inner side area with high porosity in a centrifugal force field generated by rotation of the bearing assembly. The liquid metal lubrication system, the monitoring method and the mechanical equipment are used for realizing stable and long-term lubrication of the bearing in the mechanical equipment under the ultra-high temperature working condition.

Inventors

ZHOU KUN
MIAO HUI
SHAO FEI
LI YAZHONG

Assignees

中国航空发动机研究院

Dates

Publication Date: 20260512
Application Date: 20260128

Claims (10)

1. A liquid metal lubrication system comprising a bearing assembly and a liquid metal lubricant, the liquid metal lubricant filling a gap in the bearing assembly, the liquid metal lubricant containing a rare earth element; The bearing assembly comprises a bearing inner ring, a bearing outer ring, a plurality of rolling bodies and a retainer, wherein the rolling bodies are positioned in a raceway formed by the bearing inner ring and the bearing outer ring, the retainer is arranged in the raceway and used for separating and guiding the rolling bodies, the retainer is internally provided with a gradient pore structure, the porosity of the gradient pore structure is continuously reduced along the direction from the bearing inner ring to the bearing outer ring, and the gradient pore structure is used for driving the liquid metal lubricant to flow back from an outer side area with low porosity to an inner side area with high porosity in a centrifugal force field generated by rotation of the bearing assembly.
2. The liquid metal lubrication system of claim 1, wherein the liquid metal lubricant further comprises gallium, indium and zinc, the mass percent of gallium being 65% -70%, the mass percent of indium being 20% -25%, the mass percent of zinc being 9.5% -9.9%, the mass percent of rare earth elements being 0.1% -0.5%, the rare earth elements being uniformly dispersed in the liquid metal lubricant in the form of nanoparticles, based on 100% by mass of the liquid metal lubricant.
3. The liquid metal lubrication system of claim 1, wherein surfaces of the bearing inner ring and the bearing outer ring are provided with a high entropy alloy transition layer.
4. The liquid metal lubrication system of claim 3, wherein the material of the high-entropy alloy transition layer comprises cobalt, chromium, iron, nickel, and molybdenum, wherein the atomic percentage content of molybdenum is 3at.% to 5at.%, and the thickness of the high-entropy alloy transition layer is 0.8 mm to 1.2 mm.
5. The liquid metal lubrication system of claim 1, wherein the bearing assembly further comprises a seal structure comprising a first seal coupled to the bearing outer race and a second seal coupled to the bearing inner race, the first seal and the second seal being disposed opposite one another and forming a tortuous seal path therebetween for blocking leakage of the liquid metal lubricant.
6. The liquid metal lubrication system of claim 5, wherein the first seal has seal teeth formed thereon that protrude in a direction toward the second seal, and wherein a tip of the seal teeth is embedded with a shape memory alloy element.
7. The liquid metal lubrication system of claim 6, wherein the shape memory alloy element has a phase transition temperature of 280 ℃ to 320 ℃.
8. The liquid metal lubrication system of claim 1, further comprising a resistance sensor, an ultrasonic sensor, and a temperature sensor; The electrodes of the resistance sensor are arranged on the bearing inner ring and/or the bearing outer ring and are used for monitoring the resistance value of the liquid metal lubricant; the probe of the ultrasonic sensor is arranged on the radial outer side of the bearing outer ring or the bearing seat and is used for transmitting ultrasonic waves into the roller path and receiving reflected signals so as to detect the reflux state of the liquid metal lubricant driven by the gradient pore structure, and the temperature sensor is arranged on the bearing inner ring, the bearing outer ring or the retainer and is used for monitoring the temperature of at least one position of the bearing assembly.
9. A method for monitoring the lubrication state of a liquid metal lubrication system, applied to the liquid metal lubrication system according to any one of claims 1 to 8, comprising: acquiring a resistance signal of the liquid metal lubricant and an ultrasonic signal inside the bearing assembly; Judging whether the current variation of the resistance signal exceeds a first threshold value or not; Judging whether the current variation of the ultrasonic signal exceeds a second threshold value; When the current variation of the resistance signal exceeds the first threshold value and the current variation of the ultrasonic signal exceeds the second threshold value, determining that the liquid metal lubrication system has lubrication faults and generating an early warning signal.
10. A mechanical device characterized in that a liquid metal lubrication system according to any one of claims 1-8 is used.

Description

Liquid metal lubrication system, monitoring method and mechanical equipment Technical Field The disclosure relates to the technical field of engine lubrication, in particular to a liquid metal lubrication system, a monitoring method and mechanical equipment. Background Aeroengines are moving towards higher thrust weight ratios and thermal efficiencies, resulting in very severe working environments for main bearings of their core components, often operating temperatures exceeding 400 ℃ and transient temperatures even up to 1000 ℃. The synthetic hydrocarbon or ester lubricating oil widely adopted by the traditional aeroengine can undergo severe thermal oxidation reaction in the temperature range, so that the viscosity is increased, the lubricating performance is reduced, acidic substances and solid cokes are generated, the cokes can block oil paths, the continuity of a lubricating oil film is damaged, and finally serious faults of bearing wear aggravation, overheating and even blocking are caused. The liquid metal lubrication technology is a way for solving the problem of ultrahigh temperature lubrication because the liquid metal lubrication technology still keeps liquid at high temperature. However, the existing liquid metal lubrication technology is directly applied to an aeroengine, component volatilization, crystallization or harmful reaction with bearing materials are easy to occur at ultrahigh temperature, impurity particles are generated, and meanwhile, the impurity particles are easy to leak along a sealing gap to pollute the engine. Disclosure of Invention The present disclosure has been made in view of the above-described problems. The utility model provides a liquid metal lubrication system and monitoring method and mechanical equipment, stable, long-term lubrication under the super high temperature operating mode of bearing in the mechanical equipment has been realized, but accurate monitoring lubrication state in real time in the while, in time early warning lubrication failure, promotes the reliability and the security of mechanical equipment operation. In order to achieve the above object, according to one aspect of the present disclosure, there is provided the following technical solution: A liquid metal lubrication system comprising a bearing assembly and a liquid metal lubricant filled in a gap of the bearing assembly, the liquid metal lubricant containing a rare earth element; The bearing assembly comprises a bearing inner ring, a bearing outer ring, a plurality of rolling bodies and a retainer, wherein the rolling bodies are positioned in a raceway formed by the bearing inner ring and the bearing outer ring, the retainer is arranged in the raceway and used for separating and guiding the rolling bodies, the retainer is internally provided with a gradient pore structure, the porosity of the gradient pore structure is continuously reduced along the direction from the bearing inner ring to the bearing outer ring, and the gradient pore structure is used for driving the liquid metal lubricant to flow back from an outer side area with low porosity to an inner side area with high porosity in a centrifugal force field generated by rotation of the bearing assembly. According to another aspect of the present disclosure, there is provided a lubrication state monitoring method of a liquid metal lubrication system, including: acquiring a resistance signal of the liquid metal lubricant and an ultrasonic signal inside the bearing assembly; Judging whether the current variation of the resistance signal exceeds a first threshold value or not; Judging whether the current variation of the ultrasonic signal exceeds a second threshold value; When the current variation of the resistance signal exceeds the first threshold value and the current variation of the ultrasonic signal exceeds the second threshold value, determining that the liquid metal lubrication system has lubrication faults and generating an early warning signal. According to another aspect of the disclosure, the disclosure also provides a machine employing the liquid metal lubrication system of the first aspect. Compared with the prior art, in one or more technical schemes provided by the disclosure, firstly, by adding the rare earth element in the liquid metal lubricant, the rare earth element can form a stable alloy phase with the liquid metal, so that component volatilization and crystallization phenomena of the liquid metal at ultrahigh temperature are inhibited, meanwhile, the rare earth element can form a compact rare earth passivation film on the surface of the bearing material, direct contact between the liquid metal and the bearing matrix material is isolated, harmful chemical reaction of the liquid metal and the bearing matrix material is avoided, the problems that the existing liquid metal is easy to volatilize and crystallize and react with the bearing material to generate impurities are effectively solved, and the purity of the lubrica