Regardless of constructive differences and features, all elevators are arranged according to one principle.

The elevator device implies the presence of certain components, regardless of the principle of the elevator. The cabin (or platform) of the passenger elevator is fixed on steel cables, perched through the pulley (wheel with a groove or rim around the circumference) of the drive mechanism, which is a system with which force is transmitted from one place to another. The drive mechanism together with the elevator control equipment is located in the machine compartment located at the top of the mine, where signals from the elevator cabin are transmitted. These signals pass along the electrical cable, stretched inside the mine and connecting the button panel in the cabin and the control cabinet in the machine compartment. At one of the ends of steel cables are counterweight - cargo, balancing the cabin or elevator platform. Therefore, when the elevator cabin is driven by an electric motor (the elevator drive can also be hydraulic, in which the counterweight is not used, or pneumatic), the counterweight is lowered down and raise the cabin (or vice versa: the cabin is lowered, and the loads rise). At the same time, the power spent on this work is significantly reduced due to the fact that the main load on the cabin is carried out precisely due to the counterweight.

The cable dropped through the pulley, under the influence of the friction force, converts the rotation of the wheel into the progressive movement of the cable: that is, the higher the clutch force of the cable with pulley, the greater the power transmitted to the cable and the greater weight it can raise or retain. In order to ensure reliable and safe operation of a cargo elevator that raises an immeasurably greater cargo than the passenger elevator, the force of friction of the pulley cables increases due to the installation of another pulley, connected to the first, and wrap the leading wheels with cables twice. The amount of cables (which can be different) is due to the safety and reliability of the design as a whole, although each of them is designed to gravate the cabin and cargo transported in it. The lift that is equipped with an elevator may be with a gearbox or without it. If the gearbox is used in the design of the elevator, the drive of the electric drive, rotating, leads to the movement of the cordant pulley with the help of the so-called worm gear, when the progressive movement of the shaft is converted into the rotational movement of the wheel. As a rule, such mechanisms are used to raise goods to a small height at low speed. Therefore, building a country cottage where the passenger elevator will work, it will appropriate to use this kind of lift. In the mechanisms without a gearbox, the presenter pulley is directly on the engine shaft, and in this case the elevator velocity caused by such a machine can be maximum - 750 m / min.

Mine and cabin have the doors that open synchronously (historically so it happened that if the lifting device has double doors, then it is called an elevator, and if the single-holder, then the lift), remain open in accordance with the time relay settings. When the relay is triggered, the door drive electric motor slams them.

The safety of the elevator is ensured by the brake holding the counterweight and the cabin fixed. The admission of the elevator at the bottom of the mine serves as containing buffers and the tensioning device of the speed limiter, which, in turn, the ropes are associated with the catches. Locking the elevator cabin in the event of a break or loosening of cables is carried out using trappers that stop motion.

They also perform the function of the brake when the cab is exceeded or counterweight.

Bread and spectacle demanded a man at all times. In the old days, a person was looking for entertainment on weekends on the shopping areas of cities where the jesters were going, magicians, singers and other street culture figures.

This is such a spectacle and provided the public Elash Otis in the warm May Day of 1854. His show could be put in a number of illusionistic, but it is only at first glance. It was a discovery that was the basis of the safety of lifting elevators to today.

Lift Brake - Creating History

Walking on the opening area of \u200b\u200bthe lifting device (elevator), which was on the height of the fourth floor, he commanded his assistants to chop ropes. For clarity of the presence of the load on the site of the lifting device, heavy bags loaded.

Rope, breeded, Top ZEVAK hid breathing, but an elevator after a short jerk stops. So it worked the most first elevator brake device (catcher) in the world.

It is worth reminding that it was far from the first elevator in the world. The era of the construction of high-rise home took place in the 19th century, and the elevators were established in full growth. But with the growth of their installations, the statistics of the falls, well, zero mark. I had to do something!

Otis Lift Lift Design

So, what is the design of the brake system of the elevator Elaysh Otis?

The trap was a flat spring, which is actively used in automotive springs today.

Under the action of the tension of the spring, the spring acquired an arcuate shape and moved freely along the vertical guide. In the event of a cliff of the cable, the voltage from the springs was filmed, and it was reappeared into the guides, thereby blocking the movement of the elevator.

Technical device of elevators

Surely, each of us by entering the elevator asked what is there inside the elevator mine. In principle, the elevator design is on three main whales: a cabin, electric winch and counterweights, which in turn are interconnected by a cable.

The counterweight is necessary to remove the load on the engine. The mass of the counterweight is calculated as the sum of the elevator mass and half of its maximum load. The electric motor is located in most cases at the top of the elevator mines in a special room separated from the mine slab.

The most common channel type is a steel twisted cable with an insert in the middle of a hemp or synthetic rope. It seemed why inside the top of the steel cable also a rope which could increase the traction load on a minor value?

So these most ropes serve as an anti-corrosion agent! They are impregnated with oil. Thus, the steel cable is enveloped by oil film and does not rust.

Today, polymer production technology does not stand still and such a company as Schindler presented a completely polymer cable for elevator companies.

A huge plus belts that they do not require constant lubrication and has silent work. It is worth saying that the leading manufacturer of OTIS elevators has been used for a long time drive belts with internal reinforcement like timing belts in a car.

Since today we are considering a principal elevator security system, we will not sharpen our attention on the mechanisms that ensure the movement of the elevator, and we will focus on the system that will not allow the elevator during the cable break.

Lift safety devices

Elaish Otis after holding his demonstration show exclaimed - "Everything is safe, gentlemen!" And asked the pace to ensure the safety of elevators to the present. And if today there were numerous elevator cliffs with people, then our self-preservation instinct would not allow us to use the elevator. Yes, and the control bodies behind the elevator farm would not allow the transportation in the event of a high probability of the cliff of the elevator cable without security systems.

Of course from the 19th century, the elevator lift system has suffered numerous changes. In addition to the technical means, an electronic control system for the safe movement of the elevator is added to along with the terminal peripherals in the form of a variety of sensors. Despite the presence of numerous electronics, ultimately, a mechanical catcher is triggered, which has an excellent design solution on the invention of OTIIS.

Let's focus on the example of the elevator security system that were installed in high-rise homes in Soviet times. This system has not yet included complex electronic control units and operated mechanically. According to the principle - the simpler, the more reliable.

The elevator safety system can be divided into the following main nodes:

• mechanical speed limiter.
• the catcher located on the elevator cabin.
• rope binding limiter with a catcher.

Rope trap

In the case when the design was demonstrated by OTIUS, the pulling cable was simultaneously the cable of the trap. In the modern security system, the cable binding the catcher at the elevator cabin with the limiter is located separately from the main one.

Lift speed limiter

The speed limiter is located as the main electric motor in the engine room above the elevator shaft. The role of the mechanical catcher is to control the speed of the elevator cabin.

On the limiter is a pulley with a cable, which is associated with the design of the catcher at the elevator cabin.

Principle of Elevator Speed \u200b\u200bLimiter

In the event of an elevator cable break, the cabin speed increases and, accordingly, this acceleration through the cable is transmitted to the plot of the limiter. Inside the limiter, loads are located, which under the action of centrifugal force due to acceleration diverges overcoming the spring force and rest in fixed stops.

The plot of the limiter is blocked and the cable stretching actuates the device of the catcher at the elevator cabin.

Device of lift catcher

Lift catcher depending on the principle of operation are the following types:

The elevators are called stationary lifts of periodic action, in which the movement of goods or people from one level to another is made in the cockpit moving along the guides installed in the mine fenced from all sides. The most wider uses have electrically driven elevators and with cabins suspended on ropes.

In industrial enterprises, elevators are used to move various goods and equipment on floors and are an integral part of technological production. Recently, the elevators are used in mining enterprises as auxiliary lifts for intergoriborial transportation, as well as to maintain such large-scale machines as excavators, shaft lifting machines installed on tower cops, etc.

Many public utilities enterprises use freight elevators to serve various transportation in stores, libraries, garages, etc.

In administrative and public buildings, elevators are established to accelerate and facilitate the movement of people and cargo. A huge amount of housing construction in our country with an increased storeinity of new houses annually requires a large number of elevators. Passenger elevators need to be equipped with all residential buildings with more than five floors.

The modern elevator is a complex electrical automated device. It belongs to high-risk cars. Therefore, elevators should be designed, manufactured, mounted and put into operation, are upgraded, reconstructed in accordance with the requirements of the "Rules of Device and Safe Operating Lifts" (Pubel).

Along with the general requirements for reliability and safety, elevators must also meet the following specific requirements: but) Cabin stop accuracy on the specified floor; b.) limitations of acceleration and deceleration; in) Noiselessness in the work and lack of interference with radio.

Under the accuracy of the cab stop, the difference of floor cabins and floor floor marks, where the cabin stopped. The threshold formed from the inaccuracy of the stop is dangerous for the movement of passengers and goods, so its value is strictly regulated. To increase the performance of elevators, it is necessary to take possible greater acceleration and deceleration, which is particularly important for elevators of high-rise buildings with hard work. Acceleration and deceleration freely transferred by the human body without any unpleasant sensations should not exceed 2.5 m / s 2. The noise and interference of the radios arising from the work of the elevators are especially unacceptable in residential buildings and public buildings. The soundproofing ability of the walls of the engine room and the elevator mines is not allowed to be placed in the immediate vicinity of residential premises.

Requirements are presented to new elevators, the implementation of which significantly changes their design. These requirements are due to improving the reliability of the elevators, along with the creation of maximum amenities for passengers - an increase in the speed of movement of the Cabin for multi-storey buildings, calling the cabin on any floor, passing challenge, bilateral call control, automatic opening and closing doors; Modern aesthetic view of the cabin; improving the operational service life of wearing mechanisms and details; Improving the design, decrease in metal consumption, increasing the performance of the installation, etc.

Despite the significant variety of types and designs of modern passenger and freight elevators, they all consist of the main elements having the same purpose.

The main drive part of the elevator (Fig. 1.1) is lifting mechanism(winch) 22, which with help lifting ropes 21.and suspension 20.moves cabin 18.on the various floors of the served room, stopping on each floor so that floor 5 cabinwas if possible at the level floor 6 floor sites.

For equilibrium and part of the useful cargo is provided advanced 12.Cabin and other moving parts of the elevator move in a specially equipped structure, called mine 15which is equipped with floor sites doors 7 shafts.

Inside the mine (almost all over its height) guides 14 cabinsand guides 13 counterweights,and in the upper and lower parts of the frames of the cab and the counterweight install shoes 16.Covered on three sides work part of the guides 13 and 14, shoes clearly fix the cabin and counterweight in the horizontal direction.

In emergency situations, when the elevator cabin develops the speed above the permitted (limit) or at least one lifting rope, the cabin is triggered (sometimes on the counterweight) cattlers 19.Capturing the guides, the catchers are firmly held by the cab on these guides.

Catcher's trigger when the cabin speed is exceeded speed limiter 2 with rope 8 speed limiterand it tensioner 9.

In the event of a failure of the control system or counterweight, it can go below the lower operating position. To prevent hard impact of the floor of the mine at the bottom of the mine provided stopsor buffer 11,mitigating a hit when landing.

The lower part of the mine where buffer and tensioning devices are located, called picking 10.

IN machine room 23.the lifting mechanism is placed, speed limiter and control station 1.In some elevators under the engine room, above the mine, provided block roomin which install controlles (controlys).

Lift classification

By destinationthe elevators are divided into passenger, cargo-passenger, hospital and freight.

Passenger elevators serve to transport people. In passenger elevators, the movement of household goods is also allowed, provided that the total weight of passengers with a load does not exceed the lift load capacity.

Passenger elevators serve exclusively to serve passengers in administrative, public and residential buildings or have a special purpose, such as hospital or firefighters.

1 - control station; 2 - speed limiter; 3 - Door opening mechanism; 4 - Cab Doors; 5 - floor cabin; 6 - floor of the floor site; 7 - Mine doors; 8 - Rope speed limiter;

9 - tensioning device; 10 - pit; 11 - buffer; 12-rested;

16 - shoes; 17 - grain; 18 - cabin; 19 - catcher; 20 - suspension;

21 - lifting ropes; 22 - lifting mechanism; 23 - Machine room.

Figure 1.1 - Passenger elevator scheme

Depending on the speed of movement, passenger elevators are:

but) Pacific ( ); b.) speed (); in) High-speed ().

Cargo-passenger elevators intended for transporting goods and people differ from passenger only by the quality of the external finishing of the cabin and comfort.

Hospital elevators can be attributed to the passenger, but due to specific working conditions, their parameters differ from the parameters of passenger elevators and therefore are highlighted.

Freight elevators are designed for transporting goods, materials, equipment. Freight elevators in turn are divided into:

trucks working with conductorintended for transportation of goods and persons accompanying it, and therefore meet all the safety rules relating to passenger elevators;

trucks working without conductorequipped only with external control; Moving people in these elevators is not allowed;

small freightwith a carrying capacity of up to 250 kg inclusive with the floor of the cab floor to 0.9 m 2 and with a cabin height of not more than 1 m, which in turn can be divided depending on the installation site on library, store, kitchen, buffet;

releasedwith lifting ropes, covering the cabin from the bottom forming a double polyspaster, where efforts from lifting ropes when lifting the cabin as it may squeeze it up. Such a cab suspension allows you to release space over a mine from elevator equipment (winches, blocks, counterclocks) if necessary;

paving,located in buildings or more often next to them (under the sidewalk), providing for the release of the elevator platform through a special hatch to the floor or sidewalk (or above this level to a height of up to 1 m) with a cabin suspension system on ropes, similar to the release elevators.

By constructiondrive elevators are divided into the following groups.

Elevators with drum winches (Fig. 1.2 but)characterized by the fact that the ropes on which the cabin and counterweight are suspended are rigidly fixed on the drum and when the elevator is working or wound on the drum. Drum winches are distinguished by a number of shortcomings and therefore apply relatively rarely, especially in passenger elevators.

a - drum type; B - with a rope pulley

Figure 1.2 - Winches

The height of the lift of the cabin significantly affects the design of this winch.

Elevators with scanovatic pulleys (Fig. 1.2, b)characterized by the absence of hard fastening of ropes on the leading warhead - the rope pulley. The traction force in the ropes is created by friction forces between the ropes and the working surfaces of the rope pulley. These winches allow you to hang the cab and counterweights by 3, 4, 6 ropes and more without substantial complication of the design, which significantly increases the safety of the elevator and reduces the wear of the ropes.

On the design of the winch with rope pulleys, the cabin height has a slight effect, which is essential when installing elevators in high buildings.

The winches with the rope pulleys eliminates the risk of the cabinetail of the cab due to the slip of the ropes on the pulley when placing a counterweight to buffer.

By the location of winches in the buildingthere are elevators with lower and upper drive.

The lower location of the drive allows you to set it on the foundation, which significantly reduces the noise from the drive distributed by the building. The repair of the drive when it is located at the bottom is more convenient, as it is eliminated by the rise of heavy parts and mechanisms for a considerable height. However, the bottom location of the drive causes an increase in the loads on the shaft, an increase in the length of the ropes, the installation of additional deflecting blocks. Therefore, the lower location of the drive is used in the case when it is inappropriate or impossible to arrange the machine room or when it is necessary to equip it in the bottom of the building isolated from the mine.

The upper drive arrangement allows you to simplify the elevator design, reduce the load on the mine, reduce the number of rope runners, and consequently, to increase its service life, apply the ropes of 2 to 3 times less than at the lower drive location. Therefore, where conditions allow, the advantage is given to the elevators with the upper drive.

At the speed of the Cabinpassenger elevators are divided into conventional speeds in the range up to 1.4 m / s and speed with 2 m / s and more. Freight elevators cover the range of nominal velocities from 0.15 to 0.5 m / s. Most of the elevators have a speed of 0.5 m / s and only some freight elevators have low speeds (sidewalk - 0.15 m / s, small store and general purpose with a carrying capacity of 5000 kg - 0.25 m / s).

On the design of the carcassfreight elevators are divided into single-packet (ordinary) and two-chain.

Singlecases include cabins with floor sizes up to 3000 x 4000 mm.

Two-chain elevators are used to transport large-sized cargo (trucks, electricity and autocar). Cabin sizes reach 6000 x 9000 mm and more.

Under the operating conditionselevators special place occupy special elevators designed to work under such conditions as an explosive medium, low or high temperatures, or by virtue of these conditions having a special technical characteristic, such as shopping, firefighters, elevators installed in chemical enterprises.

The design of the drive elevators are: but) with reducer drive; B.) Current.

Reducer drive is used mainly in elevators with low speeds. At the same time, elevator winches consist of a high-speed electric motor, gearbox and a rope-livee organ.

In the outer winches, low-waste DC electric motors are used. Such winches are mainly high-speed and high-speed elevators.

With all the types of push-button control, the elevator is made by a person, and the stop is automatically in accordance with the assignment. By the method of arrangement of controls, elevators are with outdoor and internal control or with internal control and outdoor challenge. Outdoor management have all small and large cargo lifts without conductor. Hospital elevators are manufactured with internal control. All passenger automatic elevators have internal control and external challenges from the floor sites. There are elevators when you can call only the released cabin or make a call from the unfavorant cabin when it is moved in any direction (associated with a passing challenge). The last type of control is equipped with high-speed elevators of high-rise buildings.

Kinematic schemes of elevatov

Kinematic layout schemethey call a fundamental scheme for the interaction of the lifting mechanism with movable parts of the elevator - cabin and counterweight.

In fig. 1.3 presents the most common fundamental kinematic schemes of elevators, differing by the location of the winches in the building, the design of the cordant organ and partially appointment. In the circle circuits with a shaded midtitle correspond to the cableing organs (drum or a rope pulley), the circumference of smaller diameters - deflecting blocks or countercads, large rectangles - the cabins, and small shadrophades - counterweights.

Elevator schemes with drum drives without counterweight are presented in Fig. 1.3, a, b.In this case, the first diagram - with the lower drive location, and the second - with the top. The first scheme is carried out only with small cabin sizes or significant sizes of the diameter of the deflecting unit. With significant sizes of the cabin instead of one deflecting unit, two blocks are installed, disposed of one from the other on the appropriate distance. Each deflecting unit creates an additional rope runner, which in addition to reducing the efficiency of the elevator reduces the service life of the ropes, making the installation less economical.

a - lower location of the drum winch; b - the upper arrangement of the drum winch; B - the upper arrangement of the drum winch with a counterweight or the top layout of the winch with the rope pulley; M is the same, with a deflecting unit; d - lower location of the drum winch with a counterweight or the lower location of the winch with the rope pulley; e - the top location of the winch with the rope pulley and countercob; z - the same, with a countercover, simultaneously performing the functions of the deflecting unit; z - released elevator; and - polyspust suspension of the cab and counterweight; K - Elevator with additional counterweight

Figure 1.3 - Kinematic elevator scheme

Lack of schemes in fig. 1.3, a, B.features that balance the mass of the cabin and partially mass of the payload causes an increase in the drive power and increase energy consumption during operation.

The drum drive with a counterweight can be fundamentally applied in circuits in Fig. 1.3, in, g, d, s, and, k.Scheme in fig. 1.3, init can only be implemented with small cabin sizes or a significant diameter of the drum, since otherwise the counterweights hurt over the cab. To avoid this, apply the scheme in Fig. 1.3, g. with a deflecting unit.

Elevators with rope pulleys can not work without a counterweight, as it ensures the force of friction between the ropes and streams of the rope pulley, along the way, equalizing the mass of the cabin and the mass of the payload and thereby reducing the power-consumable drive during the operation of the elevator.

The drive with the rope pulley can be used in the circuits in Fig. 1.3, in, g, d, e, f,s and, k.Scheme in fig. 1.3, e.applicable with minor cabin sizes or large diameter of the cordant pulley; In the absence of such conditions, the scheme is used in Fig. 1.3, j. with a deflecting unit.

a - counterweight from the back of the cabin; b, in - counterweight from the cabin; r, d - passing cabin with two doors; 1 - mine; 2 - counterweight;

Figure 1.4 - Cabin and counterweight scheme in mine

In elevators according to the scheme in Fig. 1.3, d.with reference to the drive with the rope pulley, the total length of the working ropes is much smaller than in the same diagram with the drum drive, which makes a circuit with a rope pulley more economical.

To increase the rope friction forces along the rope pulley, the controlys are used according to the scheme in Fig. 1.3, e,and in cases where the countercover simultaneously performs functions and deflecting block, use a circuit in fig. 1.3, g.

In fig. 1.3, z. A fairly frequently found scheme of the release elevator is given (the sidewalk scheme is also made in the same way, and in Fig. 1.3, and -freight elevator with polyspusk suspension cabin and counterweight. In the schemes in fig. 1.3, z, I.due to the multiplicity of the polyspaster, with the same efforts in the ropes, the lift capacity increases accordingly. Release elevators and four-time polystes.

In the diagram in fig. 1.3, tothe elevator with an additional counterweight is shown. It is used in cases where it is necessary to somewhat unload the rope body due to the suspension of the additional counterweight to the ropes connecting this counterweight with the cab, bypassing the winch.

In passenger elevators, the kinematic scheme in rice is most often used. 1.3, in With a rope pulley.

The mutual location of the cabin and counterweight in the mine section is determined mainly by the direction of cargo and passenger traffic and in connection with this location of the entrance doors of the elevator. Most often, the entrance doors are located on the one hand of the cabin and mines on all floors of the building (Fig. 1.4, a B C),a counterweight - rear (Fig. 1.4, but)or on the side (Fig. 1.4, b, c)cabins. In cases where the entrance doors cannot be positioned on all floors on one side of the mine or when it is advisable to have two inputs and outputs on the floor sites, use the passing cabin with two doors (Fig. 1.4, g, e).

Characteristic of elevatov

Under the characteristic of the elevator is understood as the complex of its main parameters: load capacity, speed, cabin height, performance, number of stops, types of cabin and shaft, door types, machine room location, elevator control system.

Nominal lift lifting capacitythey call the mass of the largest lifting goods on which the elevator is calculated. In the load capacity of the elevator does not include a mass of the cabin with the equipment constantly located in it: rail tracks, monorails, tali. The lift lift includes a mass of containers (boxes, buckets, buckets), vehicles (carts, trolleys) and other devices that are not constantly in the cockpit.

Lift capacity in order to reduce the sizes is governed by gtos and specifications.

Nominal lifting capacity is calculated based on the useful cabin area of \u200b\u200bthe cabin, by schedules recommended by the "rules of device and safe operation of elevators" (Pubel) or depending

where - the specific load on 1 m 2 floor cabin, ;

Cabin area, m 2.

In the work of each elevator distinguish several speeds.

Rated speedis the speed to which the elevator is calculated when working under normal conditions. The nominal speed is made to the technical task for design in accordance with senior materials on elevator.

Operating speedthe actual speed of the elevator cabin is called operational conditions. Due to the fact that electric motors, winches and other elements of elevators do not have absolutely identical technical data, operating speeds may differ from nominal and calculated velocities.

Limit speedthe elevator is the speed of the cab, counterweight, when the emergency devices are shown. The maximum speed is regulated and is within 1.15 - 1.4 of the rated speed of the elevator, and the speed range on which the alarms should be activated, is taken depending on the value of the nominal elevator speed.

Stop speedthe elevator is called the cabin speed, in which the winch is disconnected from electrical power with simultaneous superimposition of a mechanical brake.

Stopping speed is observed in elevators with two-speed winches. For proper accuracy of the stopping of the cabin, the elevator is translated from a relatively high operating speed to a reduced (stopping), in which the winch is de-energized and slowed down until a complete stop.

Revision speedthe elevator is called the speed at which inspection (revision) elements of the elements of the elevator by serving personnel from the roof of the cabin. Audit rate must be no more than 0.36 m / s, however, for elevators at a rated speed in the range of 0.71 m / s and with a drive that does not provide reduced speed (0.36 m / s), it is allowed to carry out revision at rated speed. But only when moving down.

Modern mass use elevators cover the range of nominal speeds from 0.15 to 4 m / s. The speed of above 4 m / s is extremely rare, as the rapid rise to a large height or lowering adversely affects the well-being of passengers, causing sometimes pain in the auditory bodies. In addition, the increase in speed does not always significantly increase the performance of the elevator.

For more efficient use of high-speed passenger elevators, the lower floors (the so-called express, i.e., non-stop, zone) are not served by these elevators. For the lower floors, simple and cheap ordinary elevators are installed.

Accelerationor slowthe elevator cabins are essential for assessing the quality of the elevator. Accelerations arise mainly at the beginning of the casting of the cabin, i.e., when starting (acceleration) elevator, slowdowns - when it stops. High acceleration or deceleration reduce the acceleration time and stopping the elevator, thereby increasing its performance. However, increased accelerations create additional passenger loads, causing painful phenomena (dizziness, nausea, cramped breathing and pain). Therefore, the magnitude of the allowable accelerations (m / s 2) is limited by the following largest values \u200b\u200bat normal elevator stop:

For all elevators, except for hospital ......................... 2.

For hospital elevator ............................................. 1

In emergency cases, when stopping the "STOP" button, the slowdown should not exceed 3 m / s 2, and in emergency cases when boarding the cab and counterweight to catcher or buffer - no more than 25 m / s 2.

Cabin stop accuracyit is characterized by the magnitude of the deviation of the floor of the cab floor when the floor is stopped from the floor level. The inaccuracy of the cab stop is allowed within, mm:

For freight elevators loading with floor vehicles, and for hospital elevators ................................. ± 15

For the rest of the elevators .............................................. ± 35

A fairly accurate stop can be obtained by simple mechanical braking or the use of complex systems of the electric drive. The first method is the easiest, but it can only be applied at a small elevator speed to the beginning of braking. This is explained by the fact that electromagnetic elevator brakes have a constant braking torque due to the fact that the brake pads are pressed against springs or cargo to a constant force pulley, regardless of the amount of payload in the cabin.

Since the inertia of movable parts of the elevator varies depending on the value of the payload, and the engine shutdown and the beginning of the braking is made at a certain point when approaching the floor site, then, for example, the down-down cabin will stop faster than loaded by passing different braking paths in Compliance with the amount of payload. When lifting, the loaded cabin stops faster than empty, deviating to the appropriate value from the floor level of the floor site.

At elevated speeds, an accurate stop is achieved by using more complex electric drive control systems.

The value characterizing the accuracy of the stop of the cab (K N.or K c)they call the semi-definition between the lengths of the braking paths of the email and the loaded cab. Stop accuracy when driving up and down different.

Since the magnitude of the allowable accelerations when braking the elevator is limited, then the inhibition paths increase with the growth of the nominal rates of elevators, and therefore, the accuracy of the stop decreases.

To stop the cabin with accuracy TO\u003d ± 10 mm with an amount of acceleration (deceleration) 1.5 m / s 2 It is necessary that by the time of the imposition of brakes the speed was not more than 0.15 m / s; for K \u003d.± 50 mm The speed of the cabin must be no more than 0.5 m / s, and when braking the cab rising at a speed of 0.8 m / s, and at the same acceleration the value K \u003d. ± 120 - 150 mm.

In elevators with a higher cabin speed, a non-rotational drive with a low-speed DC motor is used, the speed of rotation of which is adjustable widely, providing the desired accuracy of the cab stop by the engine itself.

Productivity of freight elevatorit is called the number of cargo transported by an elevator per unit of time in one direction. Performance value is used in the calculations of cargo flows, the required amount of elevators, as well as when determining the required lift capacity. Measure the performance of a mass of cargo transported per 1 h.

It is determined by the dependence

where is the rated calculation of the cab, people,

- the calculated mass of 1 passenger, \u003d 80 kg;

- Cabin Filling Coefficient - For residential buildings - for administrative buildings and educational institutions.

The average speed of lifting (lowering) of the cabin is determined from the speed chart during one cycle.

What the elevator in the enterprise fell in Moscow and 5 people died. As far as I remember from school, we strongly served that the brake system in the elevators is completely inertial and mechanical (like safety belts in the car) and it will work in 99.99% of cases. So why about the fall of elevators heard almost every month then in residential buildings, then in enterprises?

"Catcher must check once in half a year, throwing an elevator on them, this is a prerequisite for operating the elevator" - I read it on one of their forums of elevators.

It is completely unclear how the cable can be broken (or not to work the brake of the cable reducer) and all elevator catchers. If there are 4 cables, you can do 4 or 12? If the catchers do not work, you can put 4 more renovations - at the cost of the entire design, it does not affect the entire design, and reliability will double.

Here are some questions and answers to lift catcher.

1. Appointment and principle of the elevator speed limiter?

The speed limiter drives the cabs (counterweight), when the drive speed of the cab down by 15-40% exceeds the nominal (for elevators at a nominal speed to 1.4 m / s inclusive). The speed limiter has a device that allows you to check its triggering and reliability of the impact on catchers when driving a cabin (counterweight) at a nominal speed. The principle of action of the speed limiter is based on the use of centrifugal power of rotating goods, which are driven by the speed limiter with a cabin connected to the cab.

2. What speed limiter got the greatest distribution in the elevator building?

The centrifugal speed limiter with the horizontal axis of rotation was greatest. It consists of a corps on which the console shaft is fixed. A pulley with two streams is installed on the shaft with ball bearings. The stream of larger diameter is a working stream of smaller diameter - control. The stream of smaller diameter is designed to land the cabin on the catchers at the rated speed, as well as for adjusting the spring limiter springs. Two loads held in the pulley, two goods held during the movement in the equilibrium position of the adjustment spring are strengthened. Speed \u200b\u200blimiters are installed in the engine room and drive the speed limiter rope.

3. How does the elevator speed limiter work?

Speed \u200b\u200blimiter works as follows.

In the working position, the rope of speed limiter goes down the stream of larger pulley diameter. When the rope is moving the speed limiter, along with the cabin, the pulley rotates at a speed corresponding to the rope speed and the cab speed. Together with the pulley, loads are rotating, which under the action of centrifugal forces seek to disperse on the sides of the axis. This movement of goods is hampered by the spring, pulling goods to the axis of rotation. If the cabin speed is more permissible, then the spring force becomes insufficient to overcome the action of centrifugal forces of goods, and cargo diverge, stretching the spring. With an increase in the radius of the rotation of goods, they engage for the stops in the housing and the pulley stops. Under the action of friction force, the rope of speed limiter lifts the lever of the mechanism for the inclusion of cabbage cabs. The system is calculated so that the friction force between the rope of the speed limiter and the stream of its pulley is sufficient to turn on the trappers. Catcher triggered and hold the cabin on the guides. After removing the cockpit from the trappers and bringing the system to its original position, the elevator can work normally.

Fig. 1. Centrifugal abnormal limiter with horizontal axis of rotation
1 - emphasis; 2 - thrust; 3 - cargo; 4 - body; 5 fingers; 6 -50; 7 - holder; 8 - pulley

4. Appointment of catcher, principle of operation and applied structures.

Cathes serve to hold the cabin (counterweight) on guides when it moves down. In the event of an increase in the speed of movement of the cabin or counterweight to the value at which the speed limiter is triggered, the cabins are equipped with cabins of all elevators, with the exception of cabins suspended on the plate circuits. According to the principle of operation, the catchers are of hard action (or sharp braking) and a sliding action (or smooth braking). Hard action catcher are used at the cabin speed to 1 m / s. At a speed of 1 m / s and more use casual acts (smooth braking).

The counterweights supply by catchers if it is located above the passage or room where people can be, or if the overlaps are not designed to strike the throat, falling with the highest speed for him.

The scheme of the mechanism of inclusion of catchers is shown in Fig. 2. Cabin by means of a rope drives a speed limiter.

Fig. 2. Device of the levers and traction mechanism of catcher
1 - clamp; 2 - lead lever; 3 - Purpose Planck; 4 - block contact of the catchers; 5 - big traction; 5 - spring focus; 7 - spring; 8 - aka; 9, 10, 13 - lock nuts; 11, 14 - adjustment coupling; 12 - lever15 - traction; 16 - shoe; 17 -klin; 18 - Rope speed limiter; 19 - Planck;) 20 - horizontal shafts; 21 - levers

The rope is pulled between the speed limiter located in the machine room, and the tensioning device installed in the pit. Using the rope clamp, the lever of the inclusion mechanism of the catchers fixed on the cabin is connected. When the elevator cabin moves, the clamp carries the right branch of the rope. Rope and cabin move at the same speed. The rope rotates the speed limiter at the same speed with which the cab is moving and moves. If the drive speed of the cabin will exceed the nominal, then the speed limiter rope will increase its speed and makes you work the speed limiter, which will stop the rope. Because the cabin will continue to move down, the lever with the clip will turn in the direction of rotation of the clockwise and drive the catches. At the same time, the lever, acting on the contact device, will turn off the winch from electrical power. As a result of the operation of the speed limiter, the catches are firmly lit guides, securely holding the cabin on them. Thus, the trappers are triggered depending on the speed of the cabin and regardless of the work of the elevator winch. According to Pubel, cattle lifters and speed limiters must have a factory plate with an indication of the manufacturer, the release date, the factory number, the type of device and the nominal elevator speed for which they are intended.

5. What are you knowing the design of the exciting devices of the catchers?

According to the design of exciting devices, catchers are divided into wedge, eccentric, roller and tick. Capturing devices of catchers can be located both on both sides and on one side of each guide. Depending on this, the catcher is called double-sided or unilateral, symmetric and asymmetrical. On elevators with nominal speeds 1.0 m / s and more widely used mites in the asymmetric design.

Chapter 2. Elevator Device

2.1. General information about elevators

62. What is called elevator? The elevator is called a terminating transport device intended for lifting and descent of people (cargo) from one level to another, the cabin (platform) of which moves along the rigid vertical guide installed in the mine, equipped on the landing (loading) locations by lockable doors.

63. How are the elevators depending on the destination? By destination, elevators are divided into: passenger, cargo-passenger, hospital, cargo with conductor, freight without conductor, small cargo. Passenger elevators serve

for the transportation of people and related small-sized goods, if the total weight does not violate the lift loading capacity. R p at the zone with C and F and R C and E elevators are intended for the length of transportation of goods and people. These elevators differ from passenger enlarged cabins. Hospital elevators serve to transport patients with hospital vehicles with accompanying personnel. G Urban elevator with a conductor are designed to transport cargoes and persons accompanying it. On freight elevators without conductor transport only loads. Small freight elevators are cargo elevators without conductor, with a carrying capacity of up to 160 kg inclusive with an area of \u200b\u200bcab floor up to 0.9 m5 and with a cabin height not more than 1 m.

64. What are the main features classify elevators? Elevators are classified according to the following basic features; the type of transported objects; the type of traction organ; elevator's drive; doors' drive; type of mine; design of the doors of the mine or cabin; location of the machine room; Type control system. According to the cargo method, the elevators are divided: on elevators with a cab and elevators with a platform; By the type of traction organ: on cable cars, chains, robes, screw and plunger; By type of drive: electrical and electro-hydraulic; on the drive doors elevators can be equipped with doors; a) manually open; b) semi-automatic; c) automatic.

65. How do mines share? Elevator shafts are divided into: a) deaf, fenced on all sides and for the entire height of wall materials; b) metal frame, fenced on all sides and all height with a metal grid or shields;

C) Combined, part of which is deaf, and part-metal frame.

66. How do you share elevators on the design of the doors of the mine and cabins? According to the design of the doors of the mine and cabins, elevators are separated by: a) elevators with swing doors; b) elevators with horizontal sliding doors; c) elevators with vertically-sliding doors.

67. What are the lifts for the location of the machine room? By location of the machine room, elevators are with a machine room, located: a) above the mine; b) directly under the shaft; c) on the side of the mine.

65. How does the elevators differ in the control system? By type of control system, elevators can be: a) with push-button

Internal control; b) with push-button outer control; c) with mixed control; d) with paired control; e) with group control.

69. What is the elevator called the release? The elevator in which the cabin is driven by force acting from the bottom, called the release.

70. What elevator is called sidewalk? The released elevator, from which the cabin at the top stop comes out of the mine, is called paving.

71. What is the nominal lift loading capacity? Nominal loading capacity is the weight of the greatest cargo, the transportation of which the elevator is calculated. The value of the commemorative capacity does not include the mass of the cabin and the mass of all devices constantly located in it (railway tracks, monorails, telly, etc.).

72. How do the nominal lifting capacity calculate? The nominal load capacity of the elevators is calculated on the principle of free filling, based on the useful area of \u200b\u200bthe cab floor, according to graphics (Fig. 1), recommended by the "rules of the device and safe operation of elevators" (Pubel) of the USSR state duty. When determining the useful area of \u200b\u200bthe floor of the cabin area occupied by one of the sashing doors when opened, the calculation is not realized. The mass of man should be taken equal to 80 kg.

73. What is called nominal elevator speed? The rated speed of the elevator is called the speed of the cabin on which the elevator is calculated.

74. What is the working speed of the elevator? The working velocity velocity is the actual speed of the elevator cabin in operating conditions. The working speed of the cabin differs from the nominal no more than 15%. By speed, elevators are divided into: passenger - from 0.63 to 4 m / s; Cargo - from 0.18 to 0.5 m / s.

75. What do you understand the characteristics (main parameters) of elevators? The characteristic is the values \u200b\u200bcharacterizing the design and technological capabilities of the elevator (i.e. the main parameters). The main parameters of passenger elevators (GOST 5746-83 *), operating with a variable three-phase current with a voltage of 220 and 380 V, the following: a) lifts with a carrying capacity of 400 kg: Cabin capacity 5 people; Rated speed - 0.63; 1.0; 16 m / s; Lifting height - 60. 70, 85 m; number of stops-10, 16, 25; b) loading

Stew 630 kg: Cabs Cabin 8 people; Rated speed - 1.0; 1.6 m / s; Lifting height - 60, 85 m; number of stops - 16, 25; c) elevators installed in public buildings and industrial enterprises (GOST 8823-85, 8824-84 *), with a carrying capacity of 800 kg: Cabin capacity 10 people; speed-1.0; 1.6; 2.5 m / s; Lifting height - 45, 65, 100 m;

D) a lifting capacity of 1000 kg: Cabin capacity

12 people; Speed \u200b\u200b- 1.0; 1.6; 2.5; 4.0 m / s; lift height 45, 65,

100, 150 m; The number of stops is 10, 16, 25; e) with a lifting capacity of 1250 kg: Cabin capacity 15 people; Nominal speed of them, respectively, 1.0; 1.6; 2.5; 4.0 m / s; lifting height

45, 65, 100, 150 m; number of stops-10, 16, 25; e) with a load capacity of 1600 kg: Cabin capacity 20 people; Rated speed - 2.5; 4.0 m / s, lifting height-100, 150 m, number of stops - 25, 25.

Monorail elevators: a) lifting capacity

1000; 2000; 3200 kg; b) rated speed, respectively, 0.4; 0.5; 0.5 m / s; c) the number of stops -45, 12. Releaseing elevators: a) carrying capacity 500; 1000; 2000; 3200 kg; b) rated speed, respectively, 0.5; 0.4 and 0.5; 0.4 and 0.5; 0.5 m / s; c) lifting height 25 m; d) the number of stops-8. Paving elevators: a) carrying capacity 500; 630 kg; b) rated speed 0.18; 0.2 m / s; c) lifting height 6.5 m; d) the number of stops - 3. The listed elevators are produced by the domestic lffaineen. Passenger and cargo-passenger lifts with a carrying capacity of 320, 500, 1000 kg with a cast speed of 0.71; 1.0; 1.4 m / s, Hospital with a carrying capacity of 500 kg, cargo capacity of 500, 1000, 2000 kg are currently exploited in large quantities in residential buildings, administrative buildings, in hospitals, in industrial and warehouses.

76. What is the productivity of the elevator? The capacity of the LNFT is called the number of passengers or the number of goods transported per unit of time. The capacity of the freight elevator depends on the nominal capacity, the values \u200b\u200bof the transported load, height and the rated velocity of the elevator, as well as from time spent stops for loading and unloading. The performance of the passenger elevator is identified by the following factors: Cabin capacity, location, use time, working conditions (residential building, institution, educational institution, etc.), height and speed of lifting; Time to fill and release the cab, time spent on operations related to starting, acceleration, slowing down and stop the cab.

77. How to divide the elevators on the design of the drive? By the design of the drive, elevator winches can be with a rope pulley and drum type. The elevator drive can be reductional or unprecedented. The drums and cordless pulleys along with ropes or chains are the traction bodies of winches. The gearbox serves to transmit rotation from the electric motor to the traction body and reduces the angular speed of the latter. At the outer winches, the drum and cordant pulleys are located on the shaft of the low-speed electric motor.

78. What is the lack of elevators with a drum winch? The main drawback of the elevators of this type is the large dimensions of the drums that increase as the height and the number of carriers of the ropes increase.

79. What are the advantages of the elevators with the rope pulley? The winch with the rope pulley allows you to significantly reduce the power of the drive electric motor and get electricity savings when the elevator is operating compared to the drum winch. The elevators with the rope pulley are simple in design. They have small overall dimensions and mass of the winch. Currently, the elevators with drums with drum winchs almost completely supplanted elevators.

80. How is the traction force in winches with a rope pulley? Traction force winches with rope pulley

it is created by friction between the ropes and the walls of the rope pulleys. The friction force depends on the corner of the girth of the rope of the cordant pulley, the shape of the profile of the stream and the magnitude of the coe-fiction of the friction between the rope and the stream surface.

81. In which elevators are welded winches with reducer drive, and on what-olofactory? Reductant-driven winches are used by IA elevators with a speed of more than 1.6 m / s. The illegal winches are used on elevators with high booth speeds. Current winchs are distinguished by a large mass and complex management systems, which increases their cost, creates difficulties in manufacturing and maintaining. The most common radical winches with worm transmission, in which the rope pulley is imposed as an end of the low-speed gearbox.

82. How are elevator winches relative to the mine? The winches for the location relative to the mine are with the lower and upper arrangement of the drive (Fig. 2).

83. In what cases the drive is located at thenime? The drive is located at the bottom only when the engine room cannot be placed over the mine.

84. What are the advantages and disadvantages of the lower and upper arrangement of the drive? The upper drive arrangement simplifies the design of the elevator, reduces the number of rope flaws, uttered its service life. The rope length decreases by 2-3 times compared to the lower drive arrangement, the efficiency efficiency increases. The lower location of the drive leads to an increase in the loads on the mine, increases the length of the ropes, makes the necessary installation of additional deflecting blocks in T. d.

85. In which mines are elevators installed? Elevators are installed in deaf (brick, reinforced concrete) or in metal frame shafts.

86. Where do the elevators have control devices? Management devices can be located: with internal control-in the cab; with external control - on the landing (loading) platform of served elevators; With mixed control-in the cab and on the landing (loading) sites.