For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmissi...For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.展开更多
Oil transfer pump is the key dynamic equipment in the process of oil and gas gathering and transportation,and its working reliability directly affects the safety of oil and gas storage and transportation.Intelligent d...Oil transfer pump is the key dynamic equipment in the process of oil and gas gathering and transportation,and its working reliability directly affects the safety of oil and gas storage and transportation.Intelligent diagnosis is a key technical method to reduce failure rate of oil transfer pump,ensure the safety of gathering and transportation process,and avoid major safety accidents caused by oil transfer pump failure.Various oil transfer pumps have been emerged in recent decades,and the common fault types and characteristics of oil transfer pump have been brought out in the review.This article highlights on the research of the fault signal and processing methods of oil transfer pump.Firstly,the fault signal of the oil transfer pump is discussed and the advantages and disadvantages of different signal extraction are analyzed.Secondly,the intelligent diagnosis method of oil transfer pump and the shortcomings of the existing methods are pointed out.Finally,the conclusions are given and the future development perspectives of oil transfer pumps are suggested.The main contribution of this review is to give a syn-thetic understanding on oil transfer pumps.展开更多
As core components of eroengine lubricating oil systems,the reliability of lubricating oil pumps is crucial for maintaining oil circulation and ensuring engine operational integrity.Rotary vane pumps(RVPs)are highly e...As core components of eroengine lubricating oil systems,the reliability of lubricating oil pumps is crucial for maintaining oil circulation and ensuring engine operational integrity.Rotary vane pumps(RVPs)are highly efficient,stable,and compact,making them suitable for eroengine lubricating oil systems.However,they suffer from performance degradation under prolonged high-speed operation,owing to vane tip wear and clearance expansion.This study numerically investigates the effects of vane tip clearance on cavitation and gas-liquid twophase flow in a high-speed RVP.The RNG k-εturbulence model,Singhal full cavitation model,and volume-of-fluid(VOF)multiphase flow model are employed.The results indicate that under single-phase oil inlet conditions,increased vane tip clearance has a minimal influence on cavitation in the pump chamber,but reduces outlet flow pulsation amplitude and volumetric efficiency.Pressure fluctuations at the pump outlet remain relatively stable,with the dominant pulsation frequency being equal to the rotational frequency.Under two-phase oil-gas conditions,increased vane tip clearance leads to decreased instantaneous flow fluctuation,induces uneven oil-gas phase distribution in the pump chamber,lowers the maximum outlet pressure,and increases leakage.Spectral analysis reveals that the dominant frequency of pressure pulsations corresponds to the shaft rotation and that the secondary frequency is the vane frequency.To optimize performance and reduce leakage,it is recommended to maintain a vane tip clearance of 0.035 mm and avoid operating the pump under high-gas-content conditions.These results provide theoretical guidance for designing and selecting RVPs,with significant implications for the further development of eroengine lubricating oil systems.展开更多
基金Project(51405010)supported by the National Natural Science Foundation of ChinaProject(2011BAG09B00)supported by the National Science and Technology Support Program of China
文摘For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.
基金This study is supported by Sichuan science and technology program(2021ZHCG0013,22ZDYF3009)China National Petroleum Corporation science and technology planning project(2020B-4121)Such supports are greatly appreciated by the authors.
文摘Oil transfer pump is the key dynamic equipment in the process of oil and gas gathering and transportation,and its working reliability directly affects the safety of oil and gas storage and transportation.Intelligent diagnosis is a key technical method to reduce failure rate of oil transfer pump,ensure the safety of gathering and transportation process,and avoid major safety accidents caused by oil transfer pump failure.Various oil transfer pumps have been emerged in recent decades,and the common fault types and characteristics of oil transfer pump have been brought out in the review.This article highlights on the research of the fault signal and processing methods of oil transfer pump.Firstly,the fault signal of the oil transfer pump is discussed and the advantages and disadvantages of different signal extraction are analyzed.Secondly,the intelligent diagnosis method of oil transfer pump and the shortcomings of the existing methods are pointed out.Finally,the conclusions are given and the future development perspectives of oil transfer pumps are suggested.The main contribution of this review is to give a syn-thetic understanding on oil transfer pumps.
基金supported by the National Natural Science Foundation of China(Grant No.52376031)the School-Enterprise Collaborative Innovation Fund for graduate students of Xi’an University of Technology(Grant No.252062402).
文摘As core components of eroengine lubricating oil systems,the reliability of lubricating oil pumps is crucial for maintaining oil circulation and ensuring engine operational integrity.Rotary vane pumps(RVPs)are highly efficient,stable,and compact,making them suitable for eroengine lubricating oil systems.However,they suffer from performance degradation under prolonged high-speed operation,owing to vane tip wear and clearance expansion.This study numerically investigates the effects of vane tip clearance on cavitation and gas-liquid twophase flow in a high-speed RVP.The RNG k-εturbulence model,Singhal full cavitation model,and volume-of-fluid(VOF)multiphase flow model are employed.The results indicate that under single-phase oil inlet conditions,increased vane tip clearance has a minimal influence on cavitation in the pump chamber,but reduces outlet flow pulsation amplitude and volumetric efficiency.Pressure fluctuations at the pump outlet remain relatively stable,with the dominant pulsation frequency being equal to the rotational frequency.Under two-phase oil-gas conditions,increased vane tip clearance leads to decreased instantaneous flow fluctuation,induces uneven oil-gas phase distribution in the pump chamber,lowers the maximum outlet pressure,and increases leakage.Spectral analysis reveals that the dominant frequency of pressure pulsations corresponds to the shaft rotation and that the secondary frequency is the vane frequency.To optimize performance and reduce leakage,it is recommended to maintain a vane tip clearance of 0.035 mm and avoid operating the pump under high-gas-content conditions.These results provide theoretical guidance for designing and selecting RVPs,with significant implications for the further development of eroengine lubricating oil systems.
