• Title, Summary, Keyword: Rotor

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Development of Current Generation Rotor (해류발전 로터의 개발)

  • Jo, Chul-Hee;Kim, Kyung-Su;Min, Kyoung-Hoon;Chung, Kwang-Sic
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.75-79
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    • 2002
  • In this research, a design guideline of current generating rotor and acceptable field rotor in offshore environment is proposed. To design rotor model, wind mill rotor design principles and turbine theories were applied based on a field rotor experimental data. To verify the compatibility of the rotor design method and to analyze the properties of design factors, 3 rotor models were designed and experimented in a circular water channel. Three rotor models were designed according to different blade numbers and blade shapes. With various flow velocities and rotor rpm, the rotor power and efficiency were measured and the properties of rotor were estimated. The results can be effectively applied to the design of current generation rotor.

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Study on HAT Current Generation Rotor (수평축 해류발전 로터의 설계와 성능해석)

  • 조철희;김경수;민경훈;양태열;이현상
    • Journal of Ocean Engineering and Technology
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    • v.16 no.1
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    • pp.58-63
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    • 2002
  • In this research, a design guideline of current generating HAT rotor and acceptable field rotor in offshore environment is proposed. To design HAT rotor model, wind mill rotor design principles and turbine theories were applied based on a field HAT rotor experimental data. To verify the compatibility of the rotor design method and to analyze the properties of design factors, 3 rotor models were designed and experimented in a circular water channel. Three rotor models were designed according to different blade numbers and blade shapes. By changing flow velocity, rotor rpm, the rotor power and efficiency were measured and the properties of rotor were estimated. The results can be effectively applied to the design of current generation rotor.

Quadrotor wake characteristics according to the change of the rotor separation distance (로터 간격에 따른 쿼드로터의 후류특성 변화 연구)

  • Lee, Seungcheol;Chae, Seokbong;Kim, Jooha
    • Journal of the Korean Society of Visualization
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    • v.17 no.3
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    • pp.46-51
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    • 2019
  • Rotor wake interaction must be considered to understand the quadrotor flight, and the rotor separation distance is an important parameter that affects the rotor wake interaction. In this study, the wake characteristics were investigated with varying the rotor separation distance. The velocity field in the rotor wake was measured using digital PIV for hovering mode at Re = 34,000, and the wake boundaries from the inner and outer rotor tips were quantitatively compared with varying the rotor separation distance. The symmetric rotor-tip vortex shedding about the rotor axis was found at a large rotor separation distance. However, the wake boundary became more asymmetric about the rotor axis with decreasing the rotor separation distance. At the minimum rotor separation distance, in particular, a faster vortex decay was observed due to a strong vortex interaction between adjacent rotors.

Design of Gerotor with Pin-tooth Inner Rotor (핀치형 내부로터의 제로터 설계)

  • Lee, Sung-chul
    • Tribology and Lubricants
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    • v.36 no.2
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    • pp.64-67
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    • 2020
  • In the conventional gerotor design, the circular arc tooth of the outer rotor is first introduced, and then the inner rotor profile is generated by simulating the outer rotor motion while the inner rotor is fixed. The profile generation of tooth meshing exhibits relativity; therefore, the outer rotor profile can be generated by the movement of the inner rotor. In this study, we propose the design of a gerotor with a pin-tooth inner rotor. First, the pin-tooth inner rotor is devised, and then the outer rotor profile is generated. The profile of the inner rotor is simply composed of equally arranged pins along a circle. The root of the inner rotor is designed as a conjugated arc of two pins. The trajectory of the pin center is obtained by the inner rotor operation, and then the outer rotor profile is determined as a parallel curve of the trajectory. In this gerotor design, the inner rotor has a simple configuration, and contact occurs between the pin parts of the inner rotor and the whole profile of the outer rotor. This affects the material selection and machining process. The pin tooth can be used to design the outer and inner rotors, enabling a double gerotor mechanism corresponding to a planetary gear system.

Effects of Intermeshing Rotor for Dispersion of Silica Agglomerates in SBR/BR Compound (Intermeshing Rotor의 구조가 SBR/BR 합성고무 복합소재의 실리카 분산에 미치는 영향의 비교)

  • Kim, Sung-Min;Kim, Kwang-Jea
    • Polymer Korea
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    • v.36 no.5
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    • pp.637-642
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    • 2012
  • The effects of mixing geometry (intermeshing vs. tangential rotor) for the dispersion and distribution of silica agglomerates in SBR/BR compound were investigated. Silica dispersion and distribution were found to be better with the intermeshing rotor compared to the tangential rotor. It was concluded that the intermeshing rotor compared to the tangential rotor delivered a higher shear stress due to interlocked rotor geometry to silica agglomerates leading to better dispersity and distribution of silica in the agglomerates.

Design and Feasibility Study of Double Gerotor (이중 제로터의 설계 및 응용 가능성에 대한 연구)

  • Lee, Sung-chul
    • Tribology and Lubricants
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    • v.35 no.4
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    • pp.215-221
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    • 2019
  • 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.

Design of Cutter Profile and the Characteristics of Vibration for Symmetric Screw Rotor (대칭형스크류로터의 커터설계와 진동특성에 관한 연구)

  • 최상훈
    • Journal of KSNVE
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    • v.5 no.2
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    • pp.257-264
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    • 1995
  • We designed the cutter profile for symmetric screw rotor and did vibration experiment of screw rotor manufactured by the designed cutter profile. The results of this study are summarized as follows. (1) We designed the cutter profile of screw rotor (4-6)(5-6) by using numerical analysis program. (2) The maximum amplitude and variation of amplitude of 5-6 profile rotor are about 30 - 36.7% and 10 - 25% smaller than those of 4-6 profile rotor, respectively. (3) As the angular velocity of rotor changes from 100 to 300 rpm, the vibration of X, Y axis in driving shaft of 5-6 profile rotor is about 10 - 20% smaller than that of 4-6 profile rotor.

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Review of Balancing Techniques for Rotor (회전분의 발란싱기술에 관한 고찰)

  • Kim, Yeong-Ju
    • 한국기계연구소 소보
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    • pp.143-161
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    • 1984
  • The mass balancing of rotors is an integral part of the study practice of the rotor dynamics. Any machine with rotating components is considered to be rotating machine. The part of a rotating machine that rotates in normal operation is generally reffered to as a rotor. A rotor is flexible if it deforms when the machine is operating at any speed up to its maximum design speed. Otherwise, the rotor is rigid. The general Purpose of the study of rotor dynamics is to increase understanding of rotor vibration phenomena and thus provide a means for controlling or eliminating these vitrations. As the efficiency of rotating machinery has been increased through reduced weight and increased speed, which implies increasement of rotor flexibility, the control of rotor vibration has become essential. Thus, the study and practice of rotor dynamaics has taken on an increasingly important role in recent years. Therefore many workers have studied about this and introduced a few balancing methods of flexible rotor, which can be classified mainly in following four sorts, 1. Polar plotting methed 2. Modal balancing method 3. Influence coefficient method 4. Unified balancing approach In this paper practical theories of rotor dynamics related to flexible rotor balancing have been reviewed and confirmed the calculation results of flexible balancing of typical rotor, as an example, respectively

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Simplified Rotor and Stator Resistance Estimation Method Based on Direct Rotor Flux Identification

  • Wang, Mingyu;Wang, Dafang;Dong, Guanglin;Wei, Hui;Liang, Xiu;Xu, Zexu
    • Journal of Power Electronics
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    • v.19 no.3
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    • pp.751-760
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    • 2019
  • Since parameter mismatch seriously impacts the efficiency and stability of induction motor drives, it is important to accurately estimate the rotor and stator resistance. This paper introduces a method to directly calculate the rotor flux that is independent of stator and rotor resistance and electrical angle. It is based on obtaining the rotor and stator resistance using the model reference adaptive system (MRAS) method. The method has a lower computation burden and less adaptation time when compared with other rotor resistance estimation methods. This paper builds three coordinate frames to analyze the rotor flux error and rotor resistance error. A number of implementation issues are also considered.

A robust indirect vector control for the rotor time constant variation of induction motors (유도전동기 회전자 시정수 변동에 강인한 간접 벡터제어)

  • 강현수;조순봉;현동석
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.365-373
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    • 1996
  • This paper presents the effects of rotor time constant variation and the on-line tuning algorithm of the rotor time constant. If the value of the rotor time constant is set incorrectly, the IFOC (Indirect Field Oriented Control)scheme exhibits deteriorated performance according to the wrong slip command. These variation effects of the rotor time constant are caused by the slip calculator where it is known that the rotor time constant play an important role in the aligned rotor flux. Using the two torque angles (stationary torque angle, rotating torque angle), the variation of the rotor time constant is identified, and the rotor time constant of the controller is tuned to the proper value of the machine. As the result, with the proposed algorithm, the dynamics of the deteriorated IFOC system, where the rotor time constant is varied, is improved. For the purpose of the validity of this proposed algorithm, the computer simulations and the experiments have been performed and the explanation of the results is presented. (author). refs., figs., tab.

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