lifting mechanism

When they say 'lifting mechanism', many people immediately imagine a simple winch drum with a cable. This, of course, is the basis, but in reality, in a mine or mine, everything is much more complex and capricious. The main mistake is to consider it an isolated node. In fact, this is the nerve center of the entire lifting installation, where mechanics, dynamics, electronics and, most importantly, human safety converge. For a long time I thought that the main thing was the traction force, until I encountered problems controlling the descent at great depths, when the inertia of the load begins to dictate its conditions to the mechanism.

Design is not just a drawing

If we take a classic mine hoist, then the heart is a drum or friction pulley. But here's something that is rarely taken into account when you first meet: the braking system is critically important. Not the emergency kind, but the operational, regulatory kind. We had a case at one of the old mines in Kuzbass - the mechanism seemed to be working properly, the engines were powerful, but there was no smooth descent. The load “pecked”, the ropes experienced unnecessary dynamic loads. The problem turned out to be an outdated hydraulic brake control system that could not keep up with the signals from the speed sensors. I had to not just change the hardware, but reflash the control unit, which was, let’s say, not the most obvious solution.

Experience worth mentioning hereLONGI Corporation. Their website https://www.ljmagnet.ru shows that they just grew out of a deep understanding of such systemic connections. They don't just make equipment, but, apparently, have gone through similar bottlenecks. Their approach to the development of mining equipment, judging by the description, is based on the integration of mechanics and electromagnetic systems, which for modernlifting mechanism- is already a necessity, not an option. The electromagnetic brakes and clutches they are working on are precisely about precision control, which cannot be achieved with pure hydraulics of the last century.

Another nuance that comes only with experience is the role of the rope. It is not simply selected based on its breaking strength. Rigidity, design (type of weaving), even the method of lubrication affect how it will fit on the drum and how it will wear out. Incorrect selection of rope can negate the benefits of the most advancedlifting mechanism. I saw how, after a month, on a new installation, “herringbones” appeared on the surface of the drum - all due to the discrepancy between the flexibility of the rope and the running radius. Machinery manufacturers often overlook this, shifting the responsibility to the rope supplier.

Electrical and control: where problems arise

A modern drive is almost always an electric motor with a frequency converter. And here lies a lot of pitfalls. A converter is not just about 'turning faster or slower'. It must provide a given speed profile, especially in the end zones, and maintain torque when lowering a heavy load, operating in recuperation mode. One of the most difficult tasks is to ensure synchronous operation of several motors on the same shaft. The slightest variation in the characteristics of the converters - and parasitic torsional vibrations appear, which “eat up” the gearbox.

We once installed a system from a well-known European brand. The mechanism is excellent, but the control software was too 'closed'. When it was necessary to adapt the logic to local conditions (for example, to change the operating algorithm when changing skips), it turned out that this was almost impossible without the manufacturer. And its specialists are thousands of kilometers away. They stood there for a week because of a generally trivial setup. After that, I began to look towards solutions where there is flexibility. Here atLONGI, for example, judging by the scale of production (4000 equipment per year) and the focus on development, they must understand the importance of adaptability of systems for different mines. Their location in Fushun, in a large industrial area, certainly means working closely with real operators, and not just assembling from catalogues.

Diagnostics is a different story. Previously, the mechanic would listen to the sound and feel the temperature of the bearing. Now we need a whole complex of sensors: vibration, temperature, brake clearance, ultrasonic control of ropes. And the main thing is that this information is not just displayed on the screen, but is analyzed and predicts wear. Without this predictive service, anyone, even the most reliablelifting mechanism, is a lottery.

Security is not a system, but a culture

You can install ten levels of protection, but if the staff does not understand their logic, sooner or later there will be a way to bypass them 'to speed up work'. Over-climb control devices, speed limiters, emergency brakes - all this must be duplicated and, what is important, regularly tested in working conditions, and not just 'on a piece of paper'. The worst enemy here is routine. When everything works day after day, vigilance becomes dull.

I remember how at one enterprise the main cage position sensor failed. The backup one worked, but due to poor contact in the terminal box (banal humidity and oxidation), the signal came late. The mechanism stopped, but already at the very top stop, with an overload. After the incident, the entire system was reviewed not at the “replace the sensor” level, but at the level of cable routing, connector types, and contact cleaning schedule. This is about the question of what safetylifting mechanism- this is 30% equipment and 70% its maintenance and understanding by all levels.

It's interesting how large manufacturers such asLONGI Corporation, with their more than 1,200 employees (of which over 60% are college-educated), approach this. Surely they don’t just sell a “box of hardware”, but prescribe regulations and conduct training. Because the equipment produced by a company with an almost 30-year history (since 1993) cannot have a reputation built on anything other than reliability in real, and not ideal, operation.

Integration into the complex: the rise is just the tip of the iceberg

Lifting mechanismdoesn't work on its own. It is tied to the system for loading and unloading skips or cages, to power supply, and to dispatching. Problems often start at the junctions. For example, the mechanism control system issues the 'start' command, but the loading system has not yet given a signal to complete. Or vice versa. Deep mutual blocking is required. We once integrated a new mechanism with an old skip tipper control system. We had to install an intermediate PLC controller, which 'translated' the communication protocols between the systems. An extra link is an extra point of potential failure.

The ideal is when the entire complex, from the bottom to the surface, is designed as a single whole. This is where the competence of a full-service company is important. Judging by the descriptionLONGIAs a business that 'primarily designs and manufactures', they have the potential for such a holistic view. An area of ​​140,000 m2 is not just workshops, it is an opportunity to assemble and test large assembled units, simulating their interaction.

Another point is maintainability. The design should allow you to quickly replace the most worn components without complete disassembly. Sometimes the beautiful and compact design of the mechanism makes it difficult to access the same brake disc. In field conditions, when time is short, this is critical. A good manufacturer will always consult with maintenance crews before closing the structure.

A look into the future: what changes and what remains eternal

Nowadays there is a lot of talk about digitalization and smart mines. Forlifting mechanismthis means moving from preventative maintenance to actual predictive maintenance. Sensor data will be fed into a digital twin that will predict the remaining life of a bearing or rope. But the foundation - the physics of processes, the mechanics of friction, the strength of materials - remains unchanged. Artificial intelligence will not replace the need for competent calculation of loads and high-quality assembly.

A direction that seems promising is ropeless lifting systems, for example, with a linear drive. But their implementation depends not only on technology, but also on the conservatism of the industry and the colossal capital costs of re-equipping existing shafts. For now, evolutionary improvement of classic rope systems is a more realistic path.

Ultimately, the success of anyonelifting mechanismis determined not by passport data, but by years of trouble-free work deep in the mine. And this success consists of three things: competent design, taking into account the realities of operation, the quality of manufacturing of each part and, most importantly, treating it as a living organism that requires not just maintenance, but understanding. Companies that have gone through this path of long practice, like the sameLONGI Corporation, probably know this better than many. Their story since 1993 is essentially a story of adapting to these rigors of real mining.