• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2004년도 춘계학술대회 논문집
• /
• pp.398-403
• /
• 2004

The demand of high speed machining is increasing because the high speed cutting providers high efficiency of process, short process time, improved metal removal capacity and better surface finish. Active magnetic bearings allow much high surface speed than conventional ball bearings and therefore greatly suitable for high speed cutting. The automatic control concept of magnetic bearing system provides ability of intelligent control of spindle system to increase accuracy and flexibility by means of adaptive vibration control. This paper describes a design and development of a milling spindle system which includes built-in motor with power 5.5㎾ and maximum speed 70,000rpm, HSK-32C tool holer and active magnetic bearing system. Magnetic actuators are designed for satisfying static load condition. The Performances of manufactured spindle system was examined for its static and dynamic stiffness, load capacity, and rotational accuracy. This spindle was run up to 70,000 rpm stably, which is 3.5 million DmN.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• 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.

• 대한기계학회논문집
• /
• 제17권2호
• /
• pp.351-358
• /
• 1993

Recently a high speed spindle system for machine tools has attracted considerable attention 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 and so on. And a lubrication experiment for evaluating the performance of the spindle system is carried out. Especially, in order to establish the lubrication conditions related to the development of a high speed spindle system, the effects of oil supply rate, rotational spindle speed and so on are studied and discussed on the bearing temperature rise, bearing temperature distribution and frictional torque. And the effect of spindle system structure on the bearing temperature distribution is investigated.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
• /
• pp.32-37
• /
• 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 system. The main god of our research is to develop technology to produce high speed spindle system utilizing magnetic bearings. As active magnetic bearings require position sensors for feedback control, a noncontact position sensor is bang developed as a part of this main goal. Once developed, it will contribute to affordable high speed spindle system. In this paper, we report the selection process of the sensor types and the experimental results with driving circuits.

• 한국정밀공학회지
• /
• 제11권1호
• /
• 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.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.604-608
• /
• 2004

In this paper, an efficient method is proposed to analyze the radial error of a miniaturized-high speed spindle system. Initially, a device is constructed for measuring the radial error motion using capacitance sensors. The capacitance sensors are placed perpendicular to the axis of the shaft and at 90o to each other. The spindle is rotated at high speed and the profile of the spindle is recorded. An algorithm is developed for analyzing the spindle data and determining the radial error of spindle. The present algorithm uses homogeneous transform matrix (HTM) method and iterative process for determining the radial error. The analysis procedure is performed for different speeds of the spindle. The data obtained from the present system and the results of evaluation are also presented in this paper. It is observed that this method is effective in determining and analyzing the spindle errors for high speed miniaturized spindle.

• 한국공작기계학회논문집
• /
• 제13권1호
• /
• pp.69-75
• /
• 2004

This paper presents the thermal characteristics analysis of a high-speed motor-separated spindle system consisted of angular contact ball bearings and built-in motor with oil-jet lubrication. 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.

• 한국공작기계학회논문집
• /
• 제17권3호
• /
• pp.59-64
• /
• 2008

Spindle units of machine tool are very important part in the manufacturing area. Recently high speed machining has become the main issue of metal cutting. To develop high speed machine tools, a lot of studies have been carried out for high speed spindle. Due to increase of the rotational speed of the spindle, there has been renewal of interest in tooling system of high speed spindle. This paper concerns the static stiffness in the main spindle interface according to variation of clamping force, rotational speed and tool holder shank. Finite element analysis is performed by using a commercial code ANSYS workbench. From the results, it has been shown that the geometry of tool holder shank is mostly influence on the variation of the static stiffness in the main spindle interface.

• 대한기계학회논문집
• /
• 제8권1호
• /
• pp.86-94
• /
• 1984

본 연구에서는 최신형 슬란트베드(slant-bed)타입의 중절삭용 NC선반주축을 대상으로 하여, 구동방식의 변경-기어변속장치를 주축으로부터 완전히 분리시키고 V벨 트에 의해 구동되는 후로팅방식의 새로운 주촉구조를 설계-을 통하여 고속에서의 주축 의 회전성능 향상을 시도하였고, 실험을 통하여 그 회전성능을 전형적인 3개의 서로 다른 재래식 선반주축모델들의 값과 비교 고찰하였다.

• 한국정밀공학회지
• /
• 제15권8호
• /
• pp.11-16
• /
• 1998

Recently, the motor-integrated spindle systems have been used to simplify the machine tool structure, to improve the motion flexibility of machine tool, and to perform the high-speed machining. In this study, a static and dynamic analysis system for motor-integrated high-speed spindle systems is developed based on Timoshenko theory, finite element method and windows programming techniques. Since the system has various analysis modules related to static deformation analysis, modal analysis, frequency response analysis, unbalance response analysis and so on, it is useful in performing systematically the design and evaluation processes of motor-integrated high-speed spindle systems under windows GUI environment.