Stability of the Internal Gear Motor and Pump: Single-Valued and Interval Analysis Technique

Trong Hoa PHAM,Dinh Tu NGUYEN 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.2

The dynamic behavior of the internal gear motor and pump is significantly influenced by the stiffness and damping characteristics of the oil lubricating film. This study addresses the stability problem of the internal gear motor and pump. The single-valued analysis is firstly used to predict the stability of internal gear motor and pump under the effect of the oil film coefficients. However, the oil lubricating film characteristics change according to operating conditions. Moreover, the internal ring gear and housing parameters are known with a certain tolerance interval owing to the manufacturing inaccuracy and poor assembly process. Consequently, the geometric parameters of the internal gear motor and pump are given as a range of values rather than single-valued quantities. This leads to significantly changes in dynamic behavior as well as stability of the internal gear motor and pump. Therefore, the interval analysis technique must be used to analyze the stability of the internal gear motor and pump. The numerical simulation is performed to prove the applicability and importance of this method. With this approach, it allows designers to evaluate the stability of internal gear motor and pump as well as analyze the effect of geometric and operating parameters on stability status of the internal gear motor and pump at the early design stage. This is the basic to expand the stable operating area for internal gear motor and pump.

Design and Analysis of Conjugated Straight-Line Internal Gear Pairs

Chen Zongbin,He Lin,Liao Jian 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.8

In comparison to involute internal gear pumps, conjugated straight-line internal gear pumps have the advantages of smaller trapped volume, lower flow ripple, and higher reliability. Conjugated straight-line internal gear pumps were invented by Truninger in 1966; however, because of their unique line type, the main characteristics of these pumps are still not completely understood. Internal gear pairs are the key component of these pumps. To better understand the performance of these pumps, the present research focused on the design of an internal gear pair. A numerical model was developed to demonstrate the design method of the conjugated straight-line internal gear pair. To point out the effective engagement of the gear pair, three fundamental requirements were considered—a conjugated point existed in the tooth profile, no interference occurred during the meshing process, and the overlap coefficient was greater than one. Furthermore, according to the design of the gear pair, flow characteristics and some optimization suggestions for tooth parameters were proposed. The main characteristics of the gear pair were compared with those of an involute gear pair. Finally, a conjugated straight-line internal gear pair machined by the linear cutting method was tested, and the obtained results revealed that the design method was correct.

Development of an electric oil pump control algorithm for an automatic-transmission-based hybrid electric vehicle considering the gear shift characteristics

Song, Minseok,Oh, Joseph,Kim, Jonghyun,Kim, Youngchul,Yi, Jaeshin,Kim, Yeonho,Kim, Hyunsoo SAGE Publications 2014 Proceedings of the Institution of Mechanical Engin Vol.228 No.1

<P>In this paper, an electric oil pump control algorithm for an automatic-transmission-based hybrid electric vehicle was proposed. Dynamic models of the hybrid electric vehicle powertrain and hydraulic control system, including a mechanical oil pump and an electric oil pump, were obtained, and a hybrid electric vehicle performance simulator was developed. Also, a flow consumption model of the hydraulic control system was constructed. To represent the characteristics of the hydraulic control system according to the change in the temperature of the automatic transmission fluid, a viscosity index concept was introduced. Based on the simulation and test results, a viscosity index–line pressure–electric oil pump power map was proposed to describe the power supply requirement according to the viscosity index and the required line pressure. Using the viscosity index–line pressure–electric oil pump power map, an electric oil pump control algorithm was suggested to control the electric oil pump by using multi-stage power for a given viscosity index. The mechanical oil pump speed at which the electric oil pump is turned off was obtained on the basis of the flow consumption model. The electric oil pump control algorithm was evaluated by experiments and simulations. The proposed electric oil pump control algorithm satisfied the target line pressure requirement according to the viscosity index. In addition, an electric oil pump control strategy during an automatic transmission gear shift was suggested for the situation in which the maximum line pressure required for the gear shift cannot be achieved by only the mechanical oil pump. The electric-oil-pump-assisted power was determined from the flow consumption model and the mechanical oil pump speed considering the gear shift. The simulation results confirmed that the electric oil pump control strategy satisfied the maximum line pressure during a gear shift.</P>

2단 클러치 타입 워터펌프의 연비향상에 대한 실험적 연구

신윤혁(Yoon Hyuk Shin),김대건(Dae Geon Kim),임동현(Dong Hyun Lim),김성철(Sung Chul Kim),손석우(Seok Woo Son) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

Generally, when internal combustion engine is started, its cooling system operated in connection with engine provides excessive cooling, resulting in unnecessary energy consumption and excessive exhaust gas emission. In case of high engine speed, excessive cooling makes combustion efficiency decrease. To enhance the efficiency of combustion engine in these case, effective control of cooling system according to operating conditions of engine can be realized by changing mass flow rate of coolant using electromagnetic clutch water pump. We designed two types of water pump; planetary gear type water pump which can reduce rotation speed of water pump by 65%, compared with pulley and on/off type water pump which can stop operation of impeller. Performance evaluation consists of warm-up test and NEDC driving performance. Warm-up test result shows that the time-shortening effect of planetary gear water pump and on/off water pump was improved by 7.3% and 24.7% respectively, compared with that of conventional base water pump. And NEDC test result shows that the fuel consumption of planetary gear water pump and on/off water pump, compared with base water pump, was improved by 7.3% and 4.0%, respectively. It is estimated that application of clutch water pumps will contribute to the improvement of engine cooling system performance, whose enhancement of fuel consumption rate is similar to that of electric water pump.

엘리베이터용 기어펌프 개발

정석훈 한국기계기술학회 2011 한국기계기술학회지 Vol.13 No.4

A gear pump is a type of pump that displaces a volume of fluid by physical or mechanical action, or positive displacement pump. Power is applied to one of the gears and transmitted to a second driven gear via meshing teeth. This paper describes the hydraulic gear pump for an elevator. In gear pump, since geometrically special forms of gear tooth, ‘ulsations’is always caused in the delivery pressure and quantity. In other words, it is found that the number of delivery pressure pulsation per each revolution is always equal to that of the gear-teeth of the gear, which is coincident with the pulsation of the ideal delivery quantity. Some experimental results are given to verify the effectiveness of the developed pump.

Numerical Analysis of Standard - Unstandard Gears for an External Gear Pumps

Ahmed Mustaffa Saleem,Bahjat Hassan Alyas,Zaid Ali Shaalan 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.1

The most widely of hydraulic applications power employed source that including low manufacturing costs and good performance are defined as the external gear pumps. In this study, the using of unstandard gears and influence on the performance of gear pumps are studied. These influences include pulsation factor of flow rate, flow rate of pump and trapped volume between two meshing gears. Matlab software has been used to evaluate performance by modifying algorithm and deriving the equations of pump flow rate. The unstandard gear is used in the study undertaken with +0.3 Rack shift coefficient. Results indicated the using of unstandard gears increase flow rate and reduce the trapped volume and pulsation flow rate factor. It was concluded that the factor of pulsation flow rate reduces as increase of teeth number which leads to pulsation flow rate stabilization.

항공기용 연료펌프 상쇄연구

이정훈,김준태 한국항공우주학회 2013 한국항공우주학회 학술발표회 논문집 Vol.2013 No.11

본 연구에서는 국내 독자기술로 개발되는 항공기용 연료승압펌프와 연료이송펌프를 개발하기 위하여 연료펌프에 대한 개념/기본설계 단계에서의 상쇄연구 내용과 그 결과를 기술하였다. 상쇄연구는 개발요구 사항에 근거하여 임펠러형상, 연료이송펌프의 형식, 모터의 형식 등에 대하여 수행하였다. 임펠러 형상은 홀의 영향을 고려하지 않고 충분한 유량 해석 결과를 얻을 것으로 판단되었고 기어펌프 방식과 베인 펌프 방식을 비교한 결과 기어펌프 방식의 연료이송펌프가 요구사항에 더 적합한 것으로 판단되었다. 모터의 형식은 효율, 내구성, 내폭발성 등의 특성이 우수한 BLDC 형식이 적당한 것으로 판단되었다. This paper describes the procedures and the results of the fuel pumps trade-off study in the conceptual and preliminary design stage in order to develop the fuel booster pump and the fuel transfer pump for an aircraft. The trade-off study was performed base on the fuel pumps requirements for the impeller configuration, the type of fuel transfer pump, and the type of motor for the fuel pumps. For the impeller configuration, we can recognize that it will be better to analyzes flux without considering the effect of the holes than with. Comparing the gear pump type and the vain pump type, the first one is more acceptable for the fuel transfer pump. For the motor type of the fuel pump, the BLDC motor type is superior to other types in a point of view for efficiency, endurance, explosive characteristics.

Design analysis and simulation of an external helical gear

이철희,양진룽,이강희,이철희 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.4

This study optimized the parameters of the helical gear based on the original external meshing helical gear pump, combined with the analysis of the stability and flow of the basic parameters of the equipment; herringbone gears were used to eliminate the axial force generated by the helical gears. An optimized helical gear rotor was built with NX. The error between the simulation and calculation results of pump displacement was 3.95% and the simulation results were valid. Analysis of the outlet pressure and lift changes (maximum change rates of 0.38% and 0.25%), pressure analysis of the XY center plane at different times in the same cycle (no pressure surge or drop), and analysis of the axial force of the primary and driven rotors (axis The axial force is close to 0) were performed. The results showed that the flow pulsation of the external gear pump was slight, the operation was smooth, vibration and friction were reduced, the wear of bearings and other components could be diminished, and the service life of the equipment was extended. The simulation results showed that the external gear pump met the design requirements.

하이브리드 선형이온원에 의한 유압 기어펌프용 Cr-DLC코팅막의 특성과 효율성능

차순용,김왕렬,박민석,권세훈,정원섭,강명창,Cha, Sun-Yong,Kim, Wang-Ryeol,Park, Min-Suk,Kwon, Se-Hun,Chung, Won-Sub,Kang, Myung-Chang 한국분말야금학회 2010 한국분말재료학회지 (KPMI) Vol.17 No.6

This paper describes the results of the application of Cr-Diamond-like carbon (DLC) films for efficiency improvement through surface modification of spur gear parts in the hydraulic gear pump. Cr-DLC films were successfully deposited on SCM 415 substrates by a hybrid coating process using linear ion source (LIS) and magnetron sputtering method. The characteristics of the films were systematically investigated using FE-SEM, nano-indentation, sliding tester and AFM instrument. The microstructure of Cr-DLC films turned into the dense and fine grains with relatively preferred orientation. The thickness formed in our Cr buffer layer and DLC coating layer were obtained the 487 nm and $1.14\;{\mu}m$. The average friction coefficient of Cr-DLC films considerably decreased to 0.15 for 0.50 of uncoated SCM415 material. The hardness and surface roughness of Cr-DLC films were measured 20 GPa and 10.76 nm, respectively. And then, efficiency tests were performed on the hydraulic gear pump to investigate the efficiency performance of the Cr-DLC coated spur gear. The experimental results show that the volumetric and mechanical efficiency of hydraulic gear pump using the Cr-DLC spur gear were improved up to 2~5% and better efficiency improvement could be attributed to its excellent microstructure, higher hardness, and lower friction coefficient. This conclusion proves the feasibility in the efficiency improvement of hydraulic gear pump for industrial applications.

상용차 24Ton급 기어펌프에 관한 연구

윤권헌(KwonHeone Youn),박세제(SeJe Park),김봉환(BongHwan Kim),김영환(YeongHwan Kim),김동환(DongHwan Kim) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.11

Gear pump is a device that changes the mechanical energy into hydraulic energy, generate pressure with flow. Excellent precision and processing gear pump is easy to measure facilitates use of involute spur gear. In this paper, in order to evaluate the formability of the gear using the finite element software AFDEX and analyzed the influence on the material, according to the shape of the preform. And than the maximum pressure of the gear housing and torque delivery analysis was performed by using software ANSYS. Such an interpretation based on the results of the experiment were evaluated. Finally, gear pump in the 24ton class of commercial vehicle were producing.