"First of all, let me tell you about the single-rope wrapping hoist."

"This kind of elevator appeared earlier and the mechanism was the simplest. Its working principle is to fix one end of the lifting wire rope to the hoist drum, and connect the lifting container to the other end bypassing the wheel on the derrick."

"Using the difference in the winding direction of the wire rope on the two reels, the two lift containers are lifted up and down when the hoist is rotating to complete the lifting task."

After Zhao Guoyang explained a few words, Yuan Qinghua, a PhD from the Department of Fluid Mechanics, asked: "Mr. Zhao, after listening to your explanation, can we understand this way?"

"The most critical point of this single-rope wrapping elevator is the material of the wire rope?"

"Well, you understand this correctly, but it's a bit one-sided. The mine hoist is an organic whole after all, and it's hard to split its parts and see."

Zhao Guoyang tapped the table with his finger and said, "But there is one thing you are not wrong. The material of the wire rope is not up to standard, which is indeed a major problem for our domestic mine hoists."

Hearing this, Yuan Qinghua nodded silently, took out a pen and made some records in the notebook.

Zhao Guoyang stared at him and continued to start his own story.

"Single-rope wrapping hoist is divided into single-roller and double-roller series. The most important key is the three components: spindle device, rope adjustment clutch, and reducer."

"As the main working mechanism of a single rope winding hoist, its functions are as follows."

"First, it is to wrap the wire rope of the hoist; second, it is to bear various normal loads, including fixed loads and working loads; third, it is to bear very high loads caused by various positive situations."

Although Zhao Guoyang's story is not fancy, it is clear and content, showing his solid basic knowledge.

Listening to his story, Li Zhaohe, who had been working on mining equipment for decades, couldn't help but secretly admire him.

"Chairman, since the spindle device is so important for a single-rope wrapping elevator, its performance requirements should be very high, right?"

When Zhao Siyan heard the sound, she couldn't help but ask.

Zhao Guoyang nodded in praise and said, "Siyan, you asked very well. Indeed, on the hoist, the spindle device is a very important component."

"Some international mine hoist companies have high requirements for this component. These companies require that the spindle device will never allow defective deformation under the action of very loads."

Hearing this, Liu Yan opened her voice in a muffled voice: "This requirement should not be difficult to achieve. You only need to use better materials for the spindle device, can't the problem be solved?"

"That's right, but you have to know that the spindle material of this mine hoist is different from the spindle material of a general machine tool..."

Liu Yan frowned slightly and said with some disdain: "Hmph, of course I know this. The commonly used material for shaft parts is No. 45 steel."

"Shafts with higher accuracy can also be selected from 40Cr, bearing steel GCr15, and spring steel 65Mn. In addition, it is not uncommon to use ductile iron as shaft parts."

After Liu Yan finished speaking, she glanced at Zhao Guoyang with a demonstrative look, meaning to tell him that this lady is not a vegetarian.

Looking at the proud look of this brainy girl, Zhao Guoyang felt a little amused.

Liu Yan glanced at Zhao Guoyang with a smile on his face, and his face looked a little ugly.

Obviously, she misunderstood that Zhao Guoyang was taking the opportunity to "examine" her proud figure.

Feeling the annoyance in Liu Yan's eyes, Zhao Guoyang quickly coughed, concealed his gaze, and then slowly spoke.

"Student Liu is worthy of being a top student in the Department of Materials of Beijing North University. His understanding of shaft materials is still very comprehensive, but..."

"But what?"

Originally, Liu Yan was a little complacent after hearing Zhao Guoyang's first sentence, but when he said the word "but" and Liu Yan's face changed and she couldn't help asking.

Zhao Guoyang put down the pen in his hand, closed his hands and said, "Student Liu seemed to have ignored one thing. The spindle device of our mine hoist uses the spindle, but the spindle is high-speed and heavy-loaded, and has a fundamental difference from the spindle of ordinary machine tools."

"This..." Liu Yan's face turned red when she heard this.

During her previous study, her understanding of spindle materials was limited to some machine tools and ordinary machinery, and there were no large-scale engineering machinery such as mine hoists.

Therefore, in the selection of materials, she made some mistakes that novices are prone to making.

Zhao Guoyang did not mean to mock her. He continued: "For spindles in high-speed and heavy-load environments, we usually use low-carbon alloy steels such as 20CrMnTi, 20Mn2B, 20Cr or 38CrMoAL nitride steel."

"Although domestic steel mills can produce these materials, there are very few that can be supplied in large quantities and have excellent quality..."

When Zhao Guoyang said this, everyone in the conference room basically understood: the problem is probably here to localize the spindle device of the mine hoist.

Seeing everyone's silent appearance, Zhao Guoyang smiled and said, "Of course, we don't have to be discouraged by this."

"As long as we try to optimize when designing, and then communicate carefully with the steel factory to allow them to carefully manufacture, there will be a great opportunity to localize the spindle device."

After saying this, Zhao Guoyang picked up the teacup and drank a sip of water, then turned his eyes to the students and said, "Do you have any questions about what I just said?"

"If there is one, it's best to bring it up now. Although our time is not enough, it is still necessary to help everyone figure it out."

After Zhao Guoyang finished speaking, several students started to discuss in a low voice.

Seeing his students discussing seriously, Ji Chongxuan nodded comfortably.

Not long after, the big man Kong Dezhong first spoke: "Mr. Zhao, there is a question. I just wanted to ask, but I haven't had a chance."

Zhao Guoyang was happy when he heard this, reached out and made a "please" gesture and said, "It's okay, you're not too late, you're asking now!"

Kong Dezhong nodded and revealed his problems.

"Mr. Zhao, what I want to ask is about the difference between single-roller and double-roller of a single-rope wrapping elevator. Can you explain it in detail to us in detail the differences between the two and their respective structural characteristics?"

When Zhao Guoyang heard this, he said "Hmm": "Of course there is no problem with this. In fact, single rolls and double rolls are academically called single cylindrical rollers and double cylindrical rollers."

"For a single cylindrical drum, the structure is relatively simple. It is a common thread rope with a roller winding surface. The first thread rope is loosened from the drum, and the corresponding thread leaks out of the drum surface and is wrapped by another thread rope."

"As for the double cylindrical drum, each of its wire ropes is wrapped around the unique drum, that is, at any moment, the wire ropes are wrapped around half of the total winding surface of the two drums."

"In this case, one roller is firmly fixed to the spindle, and the other can be movably mounted on the spindle and connected to the spindle by means of a clutch so that, if necessary, the two rollers can be rotated at the same time..."

As soon as Zhao Guoyang finished speaking, Kong Dezhong started to speak again: "Mr. Zhao, what is the purpose of the relative rotation of these two rollers?"

Zhao Guoyang raised his hand and gestured: "The rotation of the roller can make the operation of the elevator easier, because it can easily adjust the length of the gradually elongated due to the elastic deformation of the wire rope."

"In addition, the relative rotation of the two rollers can also compensate for the cut-off length due to periodic tests on the wire rope."

"So, in addition to the length of the wire rope with a height, a certain length of wire rope is also needed to be attached on the surface of each roller."

"In this way, the vertical length of one wire rope will increase while the length of the other wire rope will not be reduced..."

Zhao Guoyang's vivid description did not mention too much conceptual things, but he completely answered Kong Dezhong's questions, which made the guy feel amazed.

Xu Linlin and Chen Li on the side also praised him secretly. Even Yuan Qinghua, who had the highest education, also looked at Zhao Guoyang with admiration.

As for Liu Yan, although she still looked unwilling to give in on the surface, she was already convinced from the bottom of her heart about the theoretical basis of the mine hoist.

Just as Zhao Guoyang was about to continue to tell you about the next important component of the elevator - the reducer, Tang Wanru, who had been not very noticeable, suddenly started to make a sound.

"Zhao...Mr. Zhao, I have a question, I would like to ask you to answer it!" Although Tang Wanru's voice was low, the firmness in her tone could be heard.

Zhao Guoyang's eyes narrowed slightly, and then naturally fell on the other party.

Looking at the girl with a flushed face, Zhao Guoyang smiled and said, "Student Wanru has something to say. I have said it just now. Today's meeting is about communicating and discussing together."

"So, you don't need to be restrained!"

"What I want to ask is the material problem of the spindle device..."

Tang Wan's words did not exceed Zhao Guoyang's expectations.

After all, like Liu Yan, she is a top student in the Materials Department. It is not difficult to understand whether she asks more questions about materials.

Thinking of this, Zhao Guoyang nodded slightly and said, "Class Wanru, please ask!"

Tang Wanru nodded gently and said softly: "I just heard what Mr. Zhao said, we all have a relatively intuitive understanding of the importance of spindle devices."

"What I want to ask is that since the main shaft of the mine hoist has to bear various external loads and act on the base through the bearing."

"Then during the production process, the lift container on the spindle is heavily loaded. When there is an emergency braking or other sudden situation, the instantaneous load on the spindle may be far exceeding the usual rated load, right?"
Chapter completed!