이중 제로터의 설계 및 응용 가능성에 대한 연구

이성철 한국트라이볼로지학회 2019 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.35 No.4

A gerotor set consists of two elements, an inner rotor and an outer rotor. The outer rotor has one more tooth than the inner rotor and has its centerline positioned at a fixed eccentricity from the centerline of the inner rotor. Although gerotors come in a variety of geometric configurations, all gerotor sets share the basic principle of having generated tooth profiles that provide continuous tight sealing during operation. The size of the gerotor is proportional to the number of teeth and the amount of eccentricity. The interior of an inner rotor with a large number of teeth has an enough space to include other machine elements. In this paper, the double gerotor mechanism, constructed by putting a small gerotor in the interior of a large inner rotor, is conceptualized. The double gerotor set is composed of an inner rotor, a planetary rotor, and an outer rotor. The inside profile of the planetary rotor corresponds to the outer rotor profile of the small gerotor, and the outside profile is the inner rotor profile of the large gerotor. In the double gerotor, the centers of the inner and the outer rotor are coincident because the eccentricities of two gerotors are balanced. The operation of a double gerotor is examined by analyzing the planetary motion, and a feasibility study for application of the double gerotor for hydraulic motors and pumps is performed. The double gerotor set has much application potential as a component of hydraulic systems.

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF LUBRICATING OIL FLOW IN A GEROTOR PUMP

M. SURESH KUMAR,K. MANONMANI 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.6

Gerotor pumps are widely used in the automotive industry for engine oil lubrication, due to their high volumetric efficiency and smooth pumping action. In many cases, the lubricating oil from the sump is mixed with contaminants, such as dust and tiny solid particles, or becomes thickened, due to aging. These problems will lead to critical situations, such as increased noise, enhanced wear and erosion, and poor lubrication of the engine. These critical situation were studied by conducting a detailed CFD integrated investigation on a gerotor pump’s performance at different operating conditions in three phases, and the results are presented in this paper. In first phase, a CFD model of a gerotor pump was developed with a dynamic mesh for the rotary movement of both the inner and outer rotors. The effects on pump flow rate of important parameters, such as rotor speed, fluid viscosity and number of ports, were simulated using non-contaminated oil at room temperature and an elevated temperature of 140oC. The relationship between flow rate and pressure at different rotor speeds was predicted and validated with test data for further parametric study. The pressure ripples at different time steps were measured at different angular positions of the rotors to examine the model accuracy. It was found that the flow rate increased and pressure pulsation, as well as flow recirculation, was reduced when ports were added to the cover plate. A suction pipe with a strainer was added for the second phase to capture the undesired changes in flow behavior, such as cavitation, which is caused by negative suction at the inlet region of pump. A suitable size for the inlet suction pipe for this pump was chosen after performing tests to characterize the flow behavior with single and double ports. Next, the relationship between pressure drop and strainer porosity was determined using different porosity values for the strainers. In the final phase, oil with different concentrations of solids was simulated to measure the effect of solid particles on flow rates and pressure losses. It was observed that the intensity of the recirculation was reduced at the suction end at the higher concentration of 0.04%, due to particle inertial effects. It was also found that particle size distribution affected the overall efficiency and pressure head of the pump.

Design of Port Plate in Gerotor Pump for Reduction of Pressure Pulsation

Sang-Yeol Kim,Yun-Joo Nam,Myeong-Kwan Park 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.10

The pressure pulsation due to the gear geometry of the gerotor (generalized rotor) pump mainly occurs in an instant that the chamber of the gerotor enters the delivery port and leaves the suction one. Such a pressure pulsation may result in undesirable vibration and noise of pump components as well as cavitation in hydraulic system. Therefore, it is very important to examine the pressure characteristic of the gerotor pump at its design and analysis stages. In this paper, in order to reduce the pressure pulsation in the gerotor pump, the port plate with the relief grooves is designed by referring to as notch of vane pump and relief groove of piston pump. A series of the theoretical analyses on the pressure pulsation is performed in consideration of various design parameters of the port plate, including the installation positions of the port inlet/outlet and the groove width, and the operating conditions such as rotational velocity and delivery pressure.

자동차 엔진용 오일펌프의 유동 시뮬레이션

송경석(Kyungsuk Song),허형석(Hyungseok Heo),배석정(Sukjung Bae),이헌균(Heonkyun Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Gerotor type pump is widely used as automotive part that provide cooling, lubrication and filtration. That is positive displacement device using nested hypocycloid gear elements as their pumping mechanism. Due to the complexity of flows inside an oil pumps in both the geometry and physics, the oil pumps design was dominated by simple analytical methods. It has been argued that the numerical analysis of gerotor pump can cause problems during analysis owing to rotor clearance, grid and variable volume. In this paper, an automotive gerotor pump is analyzed using FLUENT 6.2. The goal of this study is to visualize the flow through gerotor type oil pump. The dynamic mesh model with 2.5D meshing was used to model rotor motion. These simulation accurately predict time dependant pressure and mass flowrate. CFD simulation of this paper can be used to better understand its performance.

Design of Port Plate in Gerotor Pump for Reduction of Pressure Pulsation

Kim Sang-Yeol,Nam Yun-Joo,Park Myeong-Kwan The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.10

The pressure pulsation due to the gear geometry of the gerotor (generalized rotor) pump mainly occurs in an instant that the chamber of the gerotor enters the delivery port and leaves the suction one. Such a pressure pulsation may result in undesirable vibration and noise of pump components as well as cavitation in hydraulic system. Therefore, it is very important to examine the pressure characteristic of the gerotor pump at its design and analysis stages. In this paper, in order to reduce the pressure pulsation in the gerotor pump, the port plate with the relief grooves is designed by referring to as notch of vane pump and relief groove of piston pump. A series of the theoretical analyses on the pressure pulsation is performed in consideration of various design parameters of the port plate, including the installation positions of the port inlet/outlet and the groove width, and the operating conditions such as rotational velocity and delivery pressure.

Performance Improvement of an Oil Pump: Design of Port Assembled with Gerotor (2-Ellipses-Combined Lobe)

Kwak, Hyo-Seo,Li, Sheng-Huan,Kim, Chul Korean Society for Precision Engineering 2016 International Journal of Precision Engineering and Vol.17 No.8

An internal gerotor pump is used to enhance the oil hydraulics of machine tools, automotive engines and compressor. In particular, this type of pump is used to supply lubricants in an automotive engine. Recently, improvements in automobile fuel efficiency and the reduction of noise have become critical issues. Thus, gerotor internal oil pumps have been studied for high flow rate and low noise through designs of multiple combined lobe shapes. In this study, in order to address the problems of existing oil pumps, design of a new lobe shape with 2-ellipses was developed in order to decrease a sharp change of curvature. Performance parameters of an improved gerotor (2-ellipses) were calculated and compared with those of the existing gerotor (circle and 3-ellipses). Also, we performed a computational fluid dynamics (CFD) analysis of an oil pump with the improved gerotor 2-ellipses-combined lobe shape. By using the commercial software ANSYS CFD, geometric parameters relating to the port shape, which affect the performance of flow rate and irregularity, were investigated. A re-design of the port shape was performed in order to improve fuel efficiency and reduce the noise of the oil pump.

릴리프 그루브를 이용한 제로터 펌프의 압력맥동 저감

남윤주(Yun-Joo Nam),박명관(Myeong-Kwan Park) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

The pressure pulsation due to the gear geometry of the gerotor (generalized rotor) pump mainly occurs in the instant that the chamber of the gerotor leaves from the suction port and enters the delivery one. Such a pressure pulsation may result in the undesirable vibration and noise of the pump components as well as the cavitation in the hydraulic system. Therefore, it is very important to examine the pressure characteristic of the gerotor pump at its design and analysis stages. In this paper, in order to reduce the pressure pulsation in the gerotor pump, the port plate with the relief grooves is designed by referring to as the notch of the vane pumps and the relief groove of the piston pumps. A series of the theoretical analyses on the pressure pulsation are performed in consideration of various design parameters of the port plate including the installation positions of the port inlet/outlet and the groove width.

가상 설계 환경을 활용한 지로터 펌프의 배제용적 증량 설계 사례

노대경(Dae Kyung Noh),이동원(Dong Won Lee),전정배(Jeong Bae Jeon),장주섭(Joo Sup Jang) 유공압건설기계학회 2024 드라이브·컨트롤 Vol.21 No.2

The objective of this study was to examine whether a gerotor pump used in a transmission could be converted into an electric vehicle thermal management system pump using a virtual design environment. To achieve this objective, we first built an environment that could analyze the performance of a gerotor pump in heat transfer fluid. Flow rate, pressure, and volumetric efficiency were then analyzed when using heat transfer fluid in a gerotor pump. Finally, how large the displacement volume of the pump should be designed when using a heat transfer fluid other than oil was determined. Based on results of this study, it is expected that gerotor pumps will be applied to new business fields such as electric vehicle cooling systems.

제로터 펌프의 압력맥동 저감을 위한 릴리프 그루브 설계

남윤주(Y. J. Nam) 유공압건설기계학회 2016 유공압건설기계학회 학술대회논문집 Vol.2016 No.6

This paper presents the design methodology of the relief groove for reducing the pressure ripple of the Gerotor pump. The inner and outer gears are conjugated to create a multiple of the chambers through which the working fluid is transported from the inlet port to the outlet port. Due to the geometric configuration of the Gerotor gears, both ends of the chambers are inevitably edge-shaped. The edge-shaped ends decrease the passage area between the chambers and ports and increase the flow resistance. Hence, the pressure inside the chamber is sharply varied and the pressure ripple is undesirably developed. In order to reduce the pressure ripple of the Gerotor pump, the passage area should be increased and the relief groove could be machined on both end of the ports. Therefore, this paper proposes the design methodology of the relief groove for the Gerotor pump and its effect on the reduction of the pressure ripple is proved through the simulation study.

소형 제로터 펌프의 설계 및 특성실험

김대명(D. M. Kim),구지석(J. S. Gu),오성진(S. J. Oh),함영복(Y. B. Ham),김성동(S. D. Kim) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

A gerotor type volumetric displacement pump is suitable for oil or water hydraulics. For this reason, many researchers have been studied. A gerotor pump has been widely used in various fields. In this study, we were optimized rotor profile, based on an envelope of a family of curves, is proposed. The inf1uence of the circular tooth radius and the length of eccentricity on the configuration of a gerotor pump has been explored in this paper. Throughout the experiment, performance was verified and we describe the design and volumetric displacement characteristics about small-sized gerotor pump.