Since Li Xuanqing launched the industrial development plan, he has basically not paid much attention to other military and political matters, and has devoted himself to economic development. Other matters related to civil affairs are to be arranged by the Ministry of Civil Affairs as a whole, and are to be steadily advanced in accordance with the direction and pace set by the Ministry of Civil Affairs' year-end meeting and joint meeting. There is nothing else to do in the military and politics this year, except for Xuan Yingwei to cooperate with the Department of Industry and Commerce to carry out various preparations for economic warfare, the other ministries are basically carrying out large-scale military training activities, and Wan Yi in the northwest is also actively preparing for the first war in the southwest to deal with the war set by Li Xuanqing and the Tubo Sang Xiong in Yuanzhou more than a year ago. And this year's external environment is also very good, Zhu Quanzhong is busy exterminating the big tumor of Qin Zongquan, and secondly, he must arrange Emperor Zhaozong's residence in the Eastern Capital, repair the palace, and reorganize the law of the Tang Dynasty. On the northern front, because Li Cunxiao was in Hezhong Prefecture, the relationship with the Tiance Army also eased a lot. All these gave Li Xuanqing an opportunity to develop industry.

After Li Xuanqing and Qiaoxi returned from Weinan, they began to squat in the headquarters building of the industrial group outside Chang'an, which already had a little bit of afterlife, and Li Xuanqing and Qiaoxi began to ponder the production and manufacturing of the two most important parts in the industrial development process, which were also designed by Qiaoxi and Li Xuanqing themselves - gears and pulleys.

This is the most basic and important equipment in the development of the machinery industry in later generations. Gears are actually in ancient China and the West, but ancient China did not attach importance to gears, not to mention that there are traces of gears in the Warring States period unearthed in later generations, it is said that there is a prototype of gears on the geodynamic instrument invented by Zhang Heng, but later generations did not have the slightest consciousness of applying it to other fields, but in the West gears have been valued, and the ancient Greek philosopher Aristotle also has many elaborations in "Problems of Machinery".

Li Xuanqing and Qiaoxi's pirated gear drawings are actually plagiarized from later Western literature works, but the problems faced are indeed from the drawings to the theory or the manufacturing materials must be prepared from scratch bit by bit, in the case of the industrial group has been started for three months, the gear research is still at the level of experiments, the group spent a lot of money to invite the master in the face of Li Xuanqing's various tricks and cumbersome drawings dumbfounded, and even those line analysis and mechanical reactions can not be understood. Therefore, in desperation, Li Xuanqing could only get started in person, using a steam engine that had been secretly produced as the power to connect the machine tool, and began to process the simplest herringbone gear, teaching basic mechanical knowledge while processing, and transferred the best technicians from the logistics department to participate, which took half a month, and the production and acceptance of simple gears were basically completed at the end of July. In the process of continuous explanation and hand-in-hand teaching for half a month, Li Xuanqing also continued to popularize the basic knowledge of gear production, such as the M. CAMUS theorem in later generations. That is, the common normal of the tooth contact point must pass through the node on the center line. When an auxiliary transient line rolls along the transient line (pitch circle) of the large wheel and the small wheel respectively, the two tooth profile curves formed by the auxiliary tooth shape fixed with the auxiliary transient line on the large wheel and the small wheel are conjugated with each other, which is the CAMUS theorem. It takes into account the meshing state of the two tooth surfaces; The modern concept of a touchpoint trajectory is clearly established. IN ADDITION, IN 1765, L. EULER OF SWITZERLAND PROPOSED THE MATHEMATICAL BASIS FOR THE ANALYTICAL STUDY OF INVOLUTE TOOTH SHAPE, AND CLARIFIED THE RELATIONSHIP BETWEEN THE RADIUS OF CURVATURE OF THE TOOTH CURVE AND THE POSITION OF THE CENTER OF CURVATURE OF A PAIR OF GEARS THAT ARE MESHED. Later, SAVARY further completed this method and became the EU-LET-SAVARY equation. CONTRIBUTING TO THE APPLICATION OF INVOLUTE TOOTH PROFILE WAS ROTEFT WULLS, WHO PROPOSED THAT INVOLUTE GEARS HAVE THE ADVANTAGE OF HAVING A CONSTANT ANGULAR RATIO WHEN THE CENTER DISTANCE CHANGES. In 1873, the German engineer HOPPE proposed the involute tooth shape of gears with different numbers of teeth when the pressure angle changes, thus laying the ideological foundation of modern displacement gears.

This kind of physical theorem that can not be understood without considerable mathematical knowledge in later generations is too difficult to teach to this group of ancient craftsmen who basically have no mathematical foundation around them in half a month, and even Li Xuanqing and Qiaoxi were desperate for a while, but fortunately, the road of heaven and earth is constantly comparing with the real thing, and then in the process of entering the theory, which is teaching and learning while improving, these people can finally understand Li Xuanqing's way of designing gears that seems strange now.

However, Li Xuanqing's somewhat helpless way inadvertently opened the birth of a new teaching method in the history of education, the practice of teaching method. When Li Xuanqing explained the knowledge to the technicians, Qiaoxi next to him recorded all this with a pen, and then quickly sent it to the desk of the director of the Department of Education, Yuan He, for the method that the commander of Tiance Mansion personally trained the workers Yuan He hurriedly put down the work in his hand and began to study, and soon after the official promotion in the Lingzhou Institute of Technology, even Li Xuanqing's method of making drawings on the drawings was recorded for others to imitate, all of which inadvertently opened the advancement of industrial theory.

However, for Li Xuanqing at this time, his half-month hard work has finally paid off, and now the group's technicians have been able to independently analyze the drawings provided by Li Xuanqing and start producing gears.

"Big brother, how's it going? How does it feel to be a teacher? Qiaoxi saw that Qin Yao and the workers were processing a finished steel gear in the sparks, and walked to Li Xuanqing, who was observing on the side, and said with a smile.

Li Xuanqing took a big sip of the kettle handed over by Qiaoxi, and said with a wry smile: "I finally understand what it means to pull out seedlings and help them grow." We're grafting it now. Fortunately, I finally got some results, otherwise I would have really doubted life. ”

"Don't worry, big brother, I have already written down your half-month course, and I also sent it to Director Yuanhe, I believe he will find a way to promote it, isn't the Industrial College in Lingzhou about to open? The industrial group also selected a group of ordinary disciples to go over, ready to go to further study as seeds for the future. Qiaoxi was not so pessimistic, and comforted Li Xuanqing: "If you don't understand, you can let time slowly make up for it, you can let them follow the map first, practice makes perfect." Isn't the knowledge we pirated from those sages summed up from practice? We're just a little bit ahead of schedule. ”

Li Xuanqing nodded and asked, "I've been stuck here for half a month, how is the research on the pulley group?" It won't be difficult, right? ”

Qiaoxi smiled: "Big brother, don't worry, the pulley block is much simpler than the gear, and we have used it before, so now we have begun to produce it for other fields." The mechanical principle in the complex pulley block is also very easy to explain, so now multiple groups of mixed pulley sets have also appeared, and now they have become a hot product of the industrial group. ”

Qiaoxi's words also made Li Xuanqing feel at ease, and said with a smile: "It seems that I am lagging behind, saying that Qiaoxi found out that you are not as good at physics as I am before, why are you so powerful now?" ”

"Hmph, I won't tell you." Qiaoxi gave Li Xuanqing a big roll of his eyes, and said coquettishly: "I learned well back then, but you don't know." After saying that, he laughed too.

The two whispered and laughed, Qin Yao's side was relatively complicated, a total of eighteen tooth marks of gears were placed in front of Li Xuanqing, Qin Yao touched the sweat on his head, hugged his fist at Li Xuanqing and said: "Lord Qi, madam, Qin Yao has been processed according to the drawings, please take a look." ”

Li Xuanqing looked at the basin-sized steel gear in front of him and nodded, "Do you know the principle of the use of gears?" Are you sure that the industrial group will start a number of new sets of machines, machine tools and tools? ”

Li Xuanqing's method of marking and calculating the direction of the gear and the follow-up matters on the diagram in advance made Qin Yao and others extremely uncomfortable at first, and everyone didn't know where to start with the mathematical principles and calculation formulas involved. However, after all, Qin Yao was the inheritor of the weapon manufacturing family, and after so many days of study, he basically understood what was going on, so he replied when he heard this: "I dare not say that I am completely sure, but I can give it a try." ”

Li Xuanqing nodded and didn't continue to speak, picked up the gear that had just been processed and still had heat, checked it, and flicked it with his fingers: "It seems that the raw materials are not up to standard, and the service life of this gear is problematic." After speaking, he saw Qin Yao and several technicians present, and said with a little discouraged smile on his face: "I said that there is a problem with the materials, why are you depressed?" It's not your problem, it's all you have to do is keep experimenting with new materials to find the right crafting materials. I will be responsible for following up on the steel plant, there are two things you have to do at present, one is that the production of various gears must follow the standardization requirements, and the size of each specification of gear, weight and quality must be recorded one by one. The second is to learn more in the next production process, industrial development needs to be constantly experimented and innovated, I look forward to you being able to get the highest achievement award, and Qiaoxi and I will personally present the award. ”

Li Xuanqing's words made everyone suddenly excited, you must know that this idea has no status for technical craftsmen, although Tiance Mansion has tried its best to improve their treatment and improve their social status, but freezing three feet is not a day's cold, and many times this kind of change also needs time to precipitate. And Li Xuanqing was able to eat and live with them in the factory for half a month, and now he is still looking forward to his people being able to win the award, which one can not be excited? Even Qin Yao was excited, and led everyone to salute Li Xuanqing and said: "Thank you for your praise, Qin Yao promises to lead the brothers to work hard and not live up to the expectations of the lord." ”

Li Xuanqing and Qiaoxi looked at each other and smiled, helped Qin Yao up and said, "Everyone get up, let's continue, today's task is not completed yet." The proprietress of the group said that she wanted to invite everyone to a big meal, let's hurry up, okay? ”

This sound immediately made the entire workshop respond. Li Xuanqing asked Qin Yao's processing machine to be handed over to the workers around him, and the three of them began to go to other places to start on-site guidance.

"Qin Yao, I heard that your father is going to teach at the Institute of Technology, right? Is the old man's body able to eat? Have you finished handling the affairs of your Qin family? Li Xuanqing asked as he walked.

Qin Yao smiled bitterly when he heard this: "The lord doesn't know, although my father is old, but when I heard that my lord was going to open an industrial college, he had already handed over the family business to my cousin, and took all the organic masters in the family to Lingzhou, and when he came, he also sent a group of craftsmen and drawings to the equipment department, and at the same time asked the family to move to Chang'an to join me, and I was also helpless by the old man." ”

Li Xuanqing said with a smile: "Don't complain to me, the Department of Education wanted to refuse considering the physical condition of your old man, but I didn't expect the old man to come to Chang'an to find me in person." What do you say I should do? ”

Hearing this, Qin Yao hurriedly shook his hand and said, "Don't let me go, lord, I'm still busy." There's still something to keep an eye on in the equipment department, I really can't control the old man, and besides, he never listens to me. ”

Qiaoxi was amused by Qin Yao's expression, and then forcibly covered her mouth. Li Xuanqing smiled and said, "Okay, I'll handle the old man's affairs myself." If you have real talent and learning, you can go through the procedure to enter the equipment department or the industrial group, but there is a shortage of people on both sides. However, we must tell them to abide by the law in Chang'an, otherwise Du Yuanzheng has been cracking down on illegal crimes recently, don't be caught, otherwise it will be useless for me to intercede. ”

Qin Yao said solemnly when he heard this: "Please rest assured, if they dare to violate the law, then let the patrol department arrest them directly, and I, Qin Yao, will not ignore them." ”

Li Xuanqing nodded and stopped dwelling on this issue, walked to an independent large workshop in front, looked at a huge steel monster in the center and smiled: "This is the front of the car you designed?" Why is it so ugly? ”

Li Xuanqing's words made the workers who were busy around this monster almost fall to the ground, ugly? Is it that ugly? Qiaoxi ignored these and pulled Li Xuanqing forward to take a closer look.