• Title/Summary/Keyword: Spindle System

Search Result 606, Processing Time 0.022 seconds

Vibration Suppression of HDD Spindle System Using Piezoelectric Shunt Damping (압전 션트 댐핑을 이용한 HDD 스핀들 시스템의 진동 저감)

  • 임수철;박종성;최승복;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2003.11a
    • /
    • pp.1089-1094
    • /
    • 2003
  • A main vibration source in HDD is arisen from high rotating disk/spindle, and vibration suppression of the disk-spindle system becomes a critical issue and a major concern for high performance of the drive. In this paper, we study the feasibility of suppressing unwanted vibration of disk-spindle system of the HDD by external shock and excitation utilizing piezoelectric shunt damping methodology. By considering dynamic characteristics of the disk-spindle system through modal analysis, a target vibration mode is determined and then the piezoelectric material is carefully integrated to the modified drive. In order to maximize improvement of vibration characteristics of the proposed system, shunt circuit is optimally designed via tuning processes. Finally, the vibration characteristics of the high rotating disk-spindle system of the proposed drive is experimentally evaluated in frequency domain.

  • PDF

Air Cooling Characteristics of a High Speed Spindle System for Machine Tools (공작기계용 고속주축계의 공기냉각특성에 관한 연구)

  • Choi, Dae-Bong;Kim, Suk-Il;Song, Ji-Bok
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.11 no.1
    • /
    • pp.123-128
    • /
    • 1994
  • A high speed spindle system for machine tools can be used to reduce the machining time, to improve the machining accuracy, to perform the machining of light metals and hard materials, and to unite the cutting and grinding processes. In this study, a high speed spindle system is developed by applying the oil-air lubrication method, angular contact ball bearings, injection nozzles with dual orifices, cooling jacket and so on. And an air cooling experiment for evaluating the performance of the spindle system is carried out. Especially, in ofder to establish the air cooling conditions related to the development of a high speed spindle system, the effects of cooling air pressure, oil supply rate, air supply rate and rotational spindle speed are studied and discussed on the bearing temperature rise and frictional torque. Also the effects of cooling air pressure, rotational spindle speed and spindle system structure is investigated on the bearing temperature distribution. The experiment on the test model reveals the usefulness of the air cooling method.

  • PDF

Analysis of the Dynamic Behavior of a CNC Automatic Lathe Spindle System (CNC 자동선반 스핀들시스템의 동적 거동 해석)

  • Kim, T.J.;Koo, J.H.;Lee, S.B.;Kim, M.S.
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.19 no.3
    • /
    • pp.261-267
    • /
    • 2009
  • The spindle with a built-in motor can be used to simplify the structure of machine tool system, while the rotor has unbalance mass inevitably. Therefore, it is important to recognize the effect of unbalance mass. This paper presents analysis of dynamic behavior of a high speed spindle with a built-in motor. The spindle is supported by the angular contact ball bearings and the rotor is fixed at the middle of spindle. The spindle used in CNC automatic lathe has been investigated using combined methodologies of finite elements and transfer matrices. The Houbolt method is used for the integration of the system equations and the dynamic behavior of spindle is obtained considering unbalance mass of rotor. Results show that increasing rotational speed of spindle magnifies the whirl responses of spindle seriously. Also the whirl responses of spindle are affected by the other factors such as unbalance mass and bearing stiffness.

Development of Sensor for Magnetically Levitated High Speed Spindle System (자기 부상 고속 주축계의 센서 개발)

  • Shin, Woo-Cheol;Lee, Dong-Ju;Hong, Jun-Hee;Noh, Myoung-Gyu
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.987-992
    • /
    • 2000
  • In a high speed spindle system, it is very important to monitor the operation of the spindle to prevent catastrophic damage to the system. Widely used sensors for monitoring are eddy-current and capacitive types. These sensors provide high accuracy of monitoring, but their steep prices lead to expensive high speed spindle systems. The main goal of our research is to develop technology for producing high speed spindle system utilizing magnetic bearings. As active magnetic bearings require position sensors for feedback control, a noncontact position sensor is being developed as a part of this main goal. Once developed, it will contribute to affordable high speed spindle system. This paper describes the selection process of the sensor types and the design of the driving circuit. We also report the experimental results that characterize the static and dynamic performances of the inductive sensor.

  • PDF

Thermal Analysis of a Motor-Separated Spindle System for High-Speed HMC (모터분리형 초고속 머시닝센터 주축계의 열특성 해석)

  • 김석일;권태균;나상준
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2001.10a
    • /
    • pp.237-242
    • /
    • 2001
  • This paper presents the thermal characteristics analysis of a high-speed HMC spindle system with angular contact ball bearings, built-in motor, oil-jet lubrication method, oil jacket cooling method, and so on. The spindle system is composed of the main spindle and sub-spindle which are mechanically connected by a flexible coupling. The spindles are supported by two front and rear bearings, and the built-in motor is located between the front and rear bearings of the sub-spindle. The thermal analysis model of spindle system is constructed by the finite element method, and the thermal characteristics in the design stage are estimated based on temperature distribution, heat flow and thermal deformation under the various testing conditions related to material of bearing ball, spindle speed and coolant temperature.

  • PDF

Thermal Characteristics Analysis of a High-Speed HMC Spindle System (초고속 HMC 주축계의 열특성 해석)

  • 김석일;김기상;김기태;나승표
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2001.04a
    • /
    • pp.441-446
    • /
    • 2001
  • This paper presents the thermal characteristics analysis of a high-speed HMC spindle system with angular contact ball bearings, built-in motor, oil-jet lubrication method, oil jacket cooling method, and so on. The spindle system is composed of the main spindle and sub-spindle which are mechanically connected by a flexible coupling. The spindles are supported by two front and rear bearings, and the built-in motor is located between the front and rear bearings of the sub-spindle. The thermal analysis model of spindle system is constructed by the finite element method, and the thermal characteristics in the design stage are estimated based on temperature distribution and heat flow under the various testing conditions related to material of bearing ball, spindle speed and coolant temperature.

  • PDF

Finite Element Analysis of Vibration of HDD Disk-Spindle System with Rigid Complex Spindle and Flexible Shaft (복잡한 형상의 강체 스핀들과 유연축을 고려한 HDD 디스크-스핀들 계의 고유진동 유한요소해석)

  • Lee, Sang-Hoon;Jang, Gun-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.784-789
    • /
    • 2000
  • Equations of motion are derived and solved using the finite element method substructure synthesis for the disk-spindle system with rigid spindle and flexible shaft. The disk is modeled as a flexible spinning disk by Kirchhoff plate theory and von Karman nonlinear strain. The spindle supporting the flexible disk is modeled as a rigid body to consider its complex geometry. The stationary shaft supporting the rotating disk-spindle-bearing system is modeled by Euler beam, and the ball bearings are modeled as the stiffness matrix with 5 degrees of freedom. Developed theory is applied to analyze the vibration characteristics of a 3.5" HDD and a 2.5" HDD, respectively, and modal tests are performed to verify the simulation results. This paper shows that the developed theory can be effectively applied to the rotating disk-spindle system with the spindle of complex shape.

  • PDF

Design of High Speed Composite Air Spindle System (초고속 복합재료 공기정압 주축의 설계)

  • 장승환;이대길;한흥삼
    • Composites Research
    • /
    • v.14 no.1
    • /
    • pp.47-56
    • /
    • 2001
  • In order to enhance high speed stability the composite air spindle system composed of a high modulus carbon fiber composite shaft, powder contained epoxy composite squirrel cage rotor and aluminum tool holder was designed and manufactured. For the optimal design of the composite air spindle system, the stacking sequence and thickness of the composite shaft were selected by considering the fundamental natural frequency and deformation of the system. The analysis gave results that the composite air spindle system had 36% higher natural frequency relative to a conventional air spindle system. The dynamic characteristics of the composite spindle system were compared with those of a conventional steel air spindle system. From the calculated and test results, it was concluded that the composite shaft and the power contained composite rotor were able to enhance the dynamic characteristics of the spindle system effectively due to the low inertia and high speific stiffness of the composite materials.

  • PDF

Temperature increase of the spindle bearing system having a gear on the bearing span (베어링 스팬상에 기어구동축을 갖는 스핀들 베어링 시스템의 열특성에 관한 연구)

  • Choi, Jin-kyung;Lee, Dai-Gil
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.22 no.1
    • /
    • pp.33-43
    • /
    • 1998
  • High cutting speeds and feeds are essential requirements of a machine tool structure to accomplish its basic function which is to produce a workpiece of the required geometric form with an acceptable surface finish at as high a rate of production as is economically possible. Since the bearings in high speed spindle units are the main heat source of the total cutting system, in this work, the thermal characteristics of the spindle bearing system with a tilting axis were investigated using finite element methods to improve the performance of the spindle bearing system. Based on the theoretical results, a specially designed prototype spindle bearing system has been manufactured. Using the manufactured spindle bearing system, the thermal characteristics were measured. From the comparison of the experimental results with the theoretical ones, it was found that the finite element method predicted well the thermal characteristics of the spindle bearing system.

Experimental Study on the Electrostatic Discharge in the HDD Spindle System Using Fluid Dynamic Bearings (유체동압베어링을 사용하는 하드디스크 드라이브 스핀들 시스템에서 발생하는 정전기 방전에 관한 실험적 연구)

  • Kang, Min-Gu;Jang, Gun-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.16 no.1 s.106
    • /
    • pp.75-80
    • /
    • 2006
  • This paper introduces the mechanism of the ESD(electrostatic discharge) in the HDD spindle system using FDBs(fluid dynamic bearings). When a HDD(hard disk drive) spindle system is rotating, triboelectric charging occurs in the FDBs through the friction between the lubricant and the rotating shaft or between the lubricant and stationary sleeve. And this electrostatic charge is accumulated in the rotating parts of the HDD spindle system because they are insulated from the ground by the lubricant. This research shows experimentally that the behavior of electric charge and discharge in the FDB spindle system is the same as that of a capacitor. It also measures the electrostatic voltage difference between the rotating and stationary parts in the FDB spindle system due to the change of humidity, supporting load and motor speed. This research shows that the control of ESD is required in the HDD spindle system using FDBs, because the electrostatic charge accumulated in the FDB spindle system may cause the breakdown damage of the GMR head and data loss consequently.