To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.A...To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.An automatic variable preload device was fabricated using an eccentric mass.By installing the fabricated device on a spindle,the effect of the automatic variable preload device on the performance of the spindle was analyzed.In the results of the vibration measurement of the spindle,the vibration is increased by 20%-37% according to measurement points at the maximum rotation speed of 5 000 r/min.And,in the results of the noise measurement of the spindle,the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle,respectively.Based on the results of this analysis,an improved method that reduces such effects on the performance of the spindle is proposed.展开更多
in HL-2A tokamak the system of ECRH has been consisted of two gyrotrons that each is 500 kW of the microwave output power, the frequency is 68 ±0.1 GHz and the duration is 1 s. A set of appropriate parameters of ...in HL-2A tokamak the system of ECRH has been consisted of two gyrotrons that each is 500 kW of the microwave output power, the frequency is 68 ±0.1 GHz and the duration is 1 s. A set of appropriate parameters of the power supply and the control procedure are very important during the test of gyrotrons. Basing on analysis of the phenomenon observed, we conside that the troubles came from mainly the stability of the power supply, the sequence of control, the overcurrent protection and the grounding of the system. The solutions have been put forward and the system have been improved partly. The gyrotron has been adjusted one by one. This paper introduces the analysis of power supply for gyrotrons.展开更多
基金Project(2011-0027035) supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF)funded by the Ministry of Education,Science and Technology,Korea
文摘To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed regions.An automatic variable preload device was fabricated using an eccentric mass.By installing the fabricated device on a spindle,the effect of the automatic variable preload device on the performance of the spindle was analyzed.In the results of the vibration measurement of the spindle,the vibration is increased by 20%-37% according to measurement points at the maximum rotation speed of 5 000 r/min.And,in the results of the noise measurement of the spindle,the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle,respectively.Based on the results of this analysis,an improved method that reduces such effects on the performance of the spindle is proposed.
文摘in HL-2A tokamak the system of ECRH has been consisted of two gyrotrons that each is 500 kW of the microwave output power, the frequency is 68 ±0.1 GHz and the duration is 1 s. A set of appropriate parameters of the power supply and the control procedure are very important during the test of gyrotrons. Basing on analysis of the phenomenon observed, we conside that the troubles came from mainly the stability of the power supply, the sequence of control, the overcurrent protection and the grounding of the system. The solutions have been put forward and the system have been improved partly. The gyrotron has been adjusted one by one. This paper introduces the analysis of power supply for gyrotrons.
