Linear Motor Technology Research Articles

Nikon electron beam projection lithography tool development summary

In the development of the electron beam projection lithography (EPL) tool, one of the most important tasks is to develop the high-speed vacuum stage system and reliable vacuum body system. Nikon has a long history of over 22 years in precision stage development for its optical lithography tools as well as over 10 years in electron beam (EB) instrument development such as EB 60 with NTT. Recently, lithography stages have been developed based on air bearing and linear motor technologies. It is desirable and of minimum risk to utilize those technologies for the EPL system in order to shorten total time period of development, but the requirements for the EB stage and body are much different from their optical counterparts and much more difficult. In this paper, development and implementation of the EPL vacuum stage system, vacuum body system, vacuum loader system, and control system are discussed and overviewed.

Experimental study on a novel linear electromagnetic pumping unit

High loss of energy is a common problem in all oil fields. It is mainly caused by the intrinsic disadvantage of traditional beam-pumping units, such as complex transmission devices, short stroke, low efficiency, etc. The aim of this paper is to apply electromagnetic launch technology in oil-pumping unit. Both electromagnetic launch technology and linear motor technology are combined to develop a novel direct-driven electromagnetic pumping unit (EMPU) in which each coil is driven and controlled separately. The principles and working process of the electromagnetic pumping unit are described. With the conditions of work environment being taken into consideration, experiments were conducted to test and verify the performance of the model prototype. The disadvantages of a traditional oil-pumping unit are overcome by the novel linear electromagnetic pumping unit.

Trends of Small Sized Linear Motor Technology

Trends of Small Sized Linear Motor Technology

Finite element method with BiCG solver applied to moving linear induction motors

A linear motor analysis technique was developed to solve the diffusion equation containing the displacement term, and based upon the finite element method (FEM). For the resolution of the non-symmetrical resulting matrices, the bi-conjugate gradients (BiCG) is used. The importance of the subject derives mainly from the advances concerning the linear induction motor (LIM) technology and its recent uses in urban transportation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Magnetic Guidance of Conventional Railroad Vehicles

The potential for improved dynamic performance of conventional rail vehicles through control of linear induction or synchronous motors is explored. Improvements in vehicle stability, ride quality, traction capability, track loading, derailment safety, and curving performance result from use of controllable lateral and normal forces present in the motor. Recent advances in technology originally developed for high-speed levitated vehicles are applied to conventional railroad systems which have a greater potential for near-term implementation. The dynamic performance of alternate configurations, consisting of several generic motor types mounted either on trucks or carbodies, are evaluated. Significant improvements in both lateral dynamic stability and curving performance may be realized through magnetic guidance of the trucks using force levels well within the capability of existing linear motor technology.