Extreme Manufacturing Legacy Case Study I (EMLCS I)

Theory of ASRD [1] & Its Application in WISCO's 07 Engineering Project* 

(Working Document, Please Send me e-mail if you want receiving updating information - EXUPOLI@gmail.com )

Theory's key Discover Prof. Gu Ke [3] (Figure 1.) & Co-Discover Prof. Zhong Jue [4] (Figure 2.)

By Dr. Jin Lu (Ph.D. in OptoMechaTronics, UGent 1994), Director & Founder EXUPOLI.net (Former Pre-Ph.D. Student under Profs. Gu & Zhong, & Assistant Professor in Institute of MechaTronics, CSU )

Abstract:

This 8 parts case study presents the classical extreme manufacturing example, ASRD born in WISCO' 07 engineering project in first three months in 1979. The 1700 mm wide (for Si-Steel Strip) continuous hot-rolling equipment was the widest mill stands at that time so that the design scaling up from the 1550 mm wide one met the challenging in trial operation, due to the frequent malfunctions in the last four rolling mills (from F4 to F7 mill) in the continuous hot-rolling mills. After carefully visual inspection of the SASD [5] on Gear Teeth [6] & using of the real time dynamic torque measurement technology to continuously monitor the loading history of the main driving system in the F4 ~ F7 mills, the closed-loop torsional energy flow has been reveled by CSU team led by Prof. Gu Ke in about 11:00 PM in a day in Feb.1979. The closed-loop torsional energy flow added 3~5 times larger torque (comparing with design value, i.e. the 50% of the real driving torque before the torsional energy divided into two parts equally in the the herringbone gear stand) in the main driving system, which changed the real loading surfaces of the gear teeth of the herringbone gear pairs to the theoretic unloading surfaces of the gears. The killer of this engineered equipment has been identified.

The solutions were proposed     



1. Introduction 

When Premier Zhou Enlai fell ill with cancer, Deng Xiaoping became Zhou's choice as successor, and Zhou was able to convince Chairman Mao to bring Deng Xiaoping back into politics in 1974 as First Vice-Premier, in practice running daily affairs of P.R. China. The 07 Engineering Project of WISCO was approved by Deng at that time.  

The 07 Engineering Project imports all patented technologies, known-hows & equipment from Nippon Steel to produce 70,000 ton cooled-rolling Silicon Steel Strip (S3) annually. The installation had been delayed due to the Cultural Revolution & the 3rd purge of Deng in Feb. 1976. The trail operation started in fall 1978.

However, there were frequent malfunctions in the last four rolling mills (from F4 to F7 mill) in the continuous hot-rolling mills (Figure 3.) during trail operations from June to the end of Dec. 1978. At first, there was oil leaking in the arc tooth taken over of F4. When joint China & Japan engineering inspection of  the main driving gear boxes of the mill,  the SASD on gear teeth were observed. 

At the beginning, Japanese suppliers considered inconceivable. In order to avoid extra troubles, Nippon Steel said that the problems were caused by the low quality of the lubrication oils & poor maintenance procedures for the the arc tooth taken overs & the gear boxes. However, after exchanging of new parts in taken over & gear boxes, using high quality lubrication oils with proper maintenance procedures, the same damages were induced in further trail operations.

The detailed visual inspection (VI) on the rolling mill driving systems (F4 ~ F7) were carried out after opening of the gear boxes and there were SASD on each mill's gear teeth, especially in F5, the SASD was up to 64%. The SASD were observed on the surfaces of the gear tooth, which are theoretic no-loading surfaces.

The above VI results shocked people from both Nippon Steel & WISCO since the damage evidences were against well documented design engineering principles! That is why we classify this case as the classic case study of extreme manufacturing and present the detailed case study on how the solutions have been achieved as the following:

Prof. Gu Ke, God Father of Extreme Manufacturing Academician Zhong Jue

Figure 1. Prof. Gu Ke (古可), Key Discover of TASRA, God Father of Extreme Manufacturing Figure 2. Prof. Zhong Jue(钟掘), Member of China Academe of Engineering, Co-Discover of TASRD

 
WISCO 07 Engineering Project - Silicon Steel Strip Making Front End Process
 Figure 3. WISCO 07 Eng. Project - Silicon Steel Production Process