That an elevator at an enterprise in Moscow fell and killed 5 people. As far as I remember from school we were told that brake system in elevators it is completely inertial and mechanical (like seat belts in a car) and it will work in 99.99% of cases. So why do you hear about elevators falling almost every month, either in residential buildings or in enterprises?

“Catchers should check once every six months by dropping a lift on them, this required condition operation of the elevator" - I read this on one of the forums for elevator operators.

It is completely incomprehensible how the cables can break (or the brake of the cable reducer) and all the elevator safety devices can fail. If 4 cables break, can you make 4 or 12? If the catchers do not work, you can install 4 more backup ones - this will not affect the cost of the entire structure so much, and will double the reliability.

Here are some questions and answers about elevator catchers.

1. Purpose and principle of operation of the elevator speed limiter?

The speed limiter activates the car safety catches (counterweight) when the downward speed of the car is 15-40% higher than the nominal speed (for elevators with a nominal speed of up to 1.4 m/s inclusive). The speed limiter has a device that allows you to check its operation and the reliability of the impact on the safety devices when the cabin (counterweight) moves at the rated speed. The operating principle of the speed limiter is based on the use of centrifugal force of rotating weights, which are driven by a speed limiter rope connected to the cab.

2. Which speed limiter did you get? greatest distribution in the elevator industry?

The most widely used is the centrifugal speed limiter with a horizontal axis of rotation. It consists of a housing on which a cantilever shaft is attached. A pulley with two grooves is installed on a shaft with a ball bearing. A stream with a larger diameter is a working stream, a stream with a smaller diameter is a control stream. A stream of smaller diameter is intended for landing the cab on the catchers at the nominal speed, as well as for adjusting the speed limiter spring. Two weights are hinged on the pulley, held during movement in the equilibrium position by an adjusting spring. Speed ​​limiters are installed in the machine room and are activated by a speed limiter rope.

3. How does the elevator speed limiter work?

The speed limiter works as follows.

In the working position, the speed limiter rope bends around a stream of larger pulley diameter. When the speed limiter rope moves with the car, the pulley rotates at a speed corresponding to the speed of the rope and the speed of the car. Together with the pulley, loads rotate, which under the influence centrifugal forces tend to move away from the axis. This movement of weights is prevented by a spring that pulls the weights toward the axis of rotation. If the cabin speed turns out to be higher than permissible, then the spring force becomes insufficient to overcome the action of the centrifugal forces of the loads, and the loads diverge, stretching the spring. As the radius of rotation of the loads increases, they engage the stops in the body and the pulley stops. Under the influence of friction, the speed limiter rope lifts the lever of the cab safety switch activation mechanism. The system is designed so that the friction force between the speed limiter rope and the groove of its pulley is sufficient to activate the safety devices. The catchers operate and hold the cabin on the guides. After removing the cabin from the safety devices and bringing the system into initial position the elevator can work normally.

Rice. 1. Centrifugal speed limiter with a horizontal axis of rotation
1 - emphasis; 2 - traction; 3 — cargo; 4 — body; 5—fingers; 6—spring; 7 - holder; 8 - pulley

4. Purpose of catchers, principle of operation and designs used.

Catchers serve to hold the cabin (counterweight) on the guides as it moves down. If the speed of movement of the car or counterweight increases to a value at which the speed limiter is activated, the cars of all elevators are equipped with safety devices, with the exception of cars suspended on plate chains. According to the principle of operation, catchers are divided into hard action (or sharp braking) and sliding action (or smooth braking). Hard action catchers are used at cabin speeds of up to 1 m/s. At a speed of 1 m/s or more, sliding action catchers (smooth braking) are used.

The counterweight is equipped with catchers if it is located above a passage or room where people may be, or if the ceilings are not designed to withstand the impact of the counterweight falling at the highest speed for it.

The diagram of the mechanism for turning on the catchers is shown in Fig. 2. The cabin activates the speed limiter via a rope.

Rice. 2. Design of the system of levers and rods of the catcher mechanism
1 - clamp; 2 — drive lever; 3 — pressure plate; 4 — block contact of catchers; 5—high thrust; 5 — spring stop; 7 - spring; 8 — nut; 9, 10, 13 — locknuts; 11, 14 — adjusting clutch; 12 — lever 15 — thrust; 16 — shoe; 17—wedge; 18 — speed limiter rope; 19 — bar;) 20 — horizontal shafts; 21 — levers

The rope is tensioned between the speed limiter located in the machine room and the tension device installed in the pit. Using a clamp, the lever of the catcher activation mechanism, mounted on the cabin, is connected to the rope. When the elevator car moves, the clamp carries along the right branch of the rope. The rope and the car move at the same speed. The rope rotates the speed limiter at the same speed at which it moves and the cabin moves. If the downward speed of the car exceeds the nominal speed, the speed limiter rope will increase its speed and cause the speed limiter to operate, which will stop the rope. As the cab continues to move downwards, the clamp arm will rotate in a clockwise direction and activate the safety catches. At the same time, the lever acts on contact device, will disconnect the winch from electrical power. As a result of the speed limiter being activated, the catchers will firmly clamp the guides, securely holding the cab on them. Thus, the safety devices are triggered depending on the speed of the car and regardless of the operation of the elevator winch. According to PUBEL, safety devices and speed limiters must have a nameplate indicating the manufacturer, date of manufacture, serial number, type of device and rated speed of the elevator for which they are intended.

5. What designs of catching devices do you know?

According to the design of the gripping devices, catchers are divided into wedge, eccentric, roller and pincer. The catching devices of the catchers can be located on both sides or on one side of each guide. Depending on this, catchers are called double-sided or one-sided, symmetrical or asymmetrical. On elevators with nominal speeds of 1.0 m/s and more, soft braking clamps of asymmetrical design are widely used.

The operating principle of all elevators is the same, since they all solve similar problems associated with lifting and lowering loads. But structurally, they can have a certain number of different elements, the composition of which depends on the specific purpose of the elevator equipment. The movement of the passenger or cargo compartment occurs using a drive mechanism and steel cables thrown over grooved wheels.

Since freight elevators are used to lift heavy loads, in order to ensure more security In this process, freight elevator equipment is equipped with additional pulleys, which are wrapped twice with cables for better traction with the wheels of the pulleys.

Winches freight elevators sometimes they have a gearbox, and sometimes they don’t. If there is a gearbox, then the elevator moves more slowly, and such elevators are usually used when it is necessary to move goods to low heights. This type of elevator is well suited for the construction of cottages and estates. If the winch does not have a gearbox, then the pulley wheel rotates synchronously with the motor shaft.

Winches with gearboxes are used in elevators moving at low speeds, and winches without a gearbox are used, on the contrary, in elevators moving at high speeds.

If the drive is placed at the top, the design of the lifting device is simplified, the load experienced by the elevator shaft and the number of bends in the ropes, which consequently increase their service life, are reduced.

The use of a lower location of the winch makes it possible to install it on a separate foundation, which leads to a reduction in the noise created by the operation of the elevator. Also in this case, it is easier and more convenient to repair the drive, because there is no need to lift heavy objects to great heights. The disadvantage of this method of placing the drive is a significant lengthening of the traction ropes, a significant increase in the load acting on the elevator shaft, and complication general design elevator, due to the need to install additional system deflection blocks.

Freight elevators often installed in multi-storey residential buildings (to facilitate lifting furniture and household appliances), V shopping centers(for moving goods and equipment), at manufacturing plants (where they already become part of the technological process).

Freight elevator cabins are sometimes finished with stainless steel or other materials, the quality and strength of which are chosen depending on the intended purpose of the elevator. The type of finish determines the degree of protection of the cabin from mechanical damage transported cargo and from exposure to moisture and various polluting factors. Right choice finishing material also makes it easier to clean the cabin, clean its walls and floor. Freight elevators are sometimes equipped with lighting, heating, and ventilation systems.

Small format freight elevators are called lifts. They are used to move small cargo between floors of a building in the form of linen, correspondence, food, ready-made meals, dishes, etc. Most often, lifts can be found in small and medium-sized businesses: in restaurants, hotels, laundries, holiday homes and other similar small businesses.

2016.04.25

Elevator purpose and description

Elevator PP-0611 passenger capacity 630 kg, shaft size 1850x2550 mm, cabin doors - 800 mm, fire resistance EI-30, 9 stops. Lighting - fluorescent lamps, control station - vertical module "Column" made of stainless steel, illuminated buttons, floor call buttons made of stainless steel with backlight, handrail made of stainless steel. steel, mirror on the back wall to the handrail, low-noise winch.

An elevator is designed to lift and descend people. In some cases, it is allowed, accompanied by a passenger, to lift and lower loads whose weight and dimensions together do not exceed the rated lifting capacity of the elevator and do not damage the equipment and decoration of its cabin.

Composition and structure of the elevator

The elevator consists of components located in the shaft and machine room. The machine room and the elevator shaft form the building's building structures (brickwork, concrete blocks, etc.)

The main components of the elevator are: winch, cabin, counterweight, cabin guides and counterweights, shaft doors, speed limiter, pit components and parts, electrical equipment and electrical wiring.

The general view of the elevator is shown on the poster.

Transportation of passengers and cargo is carried out in the cabin, which moves along vertical guides. The movement of the cabin and counterweight is carried out by a winch installed in the machine room, using traction ropes. The speed limiter, control device, and input device are also located there.

At the bottom of the shaft (pit) there is stretching device speed limiter rope connected by a rope to the speed limiter, as well as cabin and counterweight buffer devices.

To enter and exit the cabin, the height of the shaft has a number of openings closed by shaft doors. The doors are opened and closed using a drive installed on the cab. The shaft doors open only when the cabin is on a given floor. If there is no cabin on the floor, opening the shaft door from the outside is only possible with a special key.

The components of the elevator in the construction part of the building are placed in a certain relationship relative to each other, ensuring their coordinated interaction.

Operating principle of the elevator

The general operating principle of the elevator is as follows:

When you press the call button, an electrical impulse (call) is sent to the elevator control device. If the cabin is at the stop from which the call came, the doors of the cabin and the shaft at this stop open, if the cabin is not present, then a command is given to move it. Voltage is applied to the winding of the winch electric motor and to the coil of the brake electromagnet, the brake pads are released and the electric motor rotor begins to rotate, ensuring, with the help of a worm gearbox, the rotation of the traction pulley, which, due to frictional forces, sets the cabin and counterweight in motion.

The operating cycle of the main elevator drive in normal mode is as follows: a signal for setting the direction of movement is received from the control device to the inverter, and by closing the contacts of the starter, the motor winding is connected to the converter. From the contacts of the relay built into the inverter, a signal is sent to the control device that the inverter is ready for operation. The motor is supplied with the voltage necessary to create the holding torque. After the current in the motor windings increases to a value that ensures the holding torque, the control device receives a corresponding signal. After this, the mechanical brake is removed, and the inverter receives a signal to set the operating speed level. After receiving this signal, the inverter generates voltage on the motor winding in such a way that it ensures a smooth start of the elevator car with the required accelerations and jerks up to working speed. After hitting the deceleration sensor, the control device sends a signal to set the reduced speed to the inverter. The inverter generates a voltage that ensures smooth braking up to reaching speed. The elevator continues to move at a reduced speed until it hits the sensor precise stop, after which, upon command from the control device, the inverter generates a voltage that ensures final braking and holding.

When the elevator car moves along the shaft, the deceleration sensor sequentially passes through the deceleration shunts located between the floors, and between the floors there are two shunts: one for deceleration when moving up, the other for deceleration when moving down, with each pass the deceleration sensor opens.

Figure 1.1 shows the general layout of elevator deceleration shunts with speeds from 0.5 to 1.6 m/s. For elevators with a speed of 0.5 to 1.6 m/s, the deceleration command is generated by the second impulse from the deceleration sensor after passing the previous precise stop.

Figure 1.1 Location of shunts between floors

After stopping the motor with the inverter, a signal indicating the end of movement is sent to the control device, upon receipt of which a mechanical brake is applied, the motor is disconnected from the inverter, and all command signals from the inverter are removed. The operating cycle of the main drive is then completed.

The cabin stops, the door drive is activated, the cabin and shaft doors open.

When you press the order button of the push-button post located in the cabin, the doors of the cabin and the shaft are closed, and the cabin is sent to the floor whose order button is pressed.

Upon arrival at the required floor and passengers exit, the doors are closed and the cabin stands at a stop until the button of any calling device is pressed again.

Elevator mechanisms and devices

Winch

The winch is installed in the MP and is designed to drive the cabin and counterweight.

The main components of the winch are an electric motor, a brake, a frame, a pitcher, a subframe, and a shock absorber.

All elements of the winch are mounted on a frame, which is mounted on a subframe through shock absorbers. The subframe rests on the MP ceiling.

Geared winches can be used, mainly produced by OTIS, State Unitary Enterprise "Mogilev-liftmash", Montanari (Italy) and gearless type WSG-08 SAD WITTUR.

Cylindrical worm gearbox, with worm shaft arrangement winch OTIS Vertical, State Unitary Enterprise "Mogilevliftmash" and Montanari horizontal, designed to reduce the rotation speed while simultaneously increasing the torque on the output shaft; double brake, shoe, normally closed type, designed to stop and hold stationary condition of the elevator cabin and counterweight when the winch engine is not running. The length of the springs and the air gap are adjusted in accordance with the instructions of the winch manufacturer. The electric motor of the gear winches is an asynchronous two-speed with a squirrel-cage rotor; temperature protection sensors are built into the stator winding. The crankshaft converts rotational motion into translational motion of the traction ropes due to the friction force that arises between the ropes and the pulley streams under the influence of the gravity of the cabin and the counterweight. The outlet block is used to ensure that the escape points of the winch ropes coincide with the centers of the cabin suspension and counterweight (Fig. 1.2, size A). The diameters of the hoist shaft D and the outlet block d, the angle of grip of the hoist rope ropes a, size A (Fig. 1.2) for each type of winch are given in 6 operational documentation from the winch manufacturer, which is attached to the elevator as a separate document.

Figure 1.2 OTIS winch

electric motor, 2 – brake, 3 – frame, 4 – driveshaft, 5 – outlet block, 6 – subframe, 7 – shock absorber, 8 – subframe, 9 – gearbox.

Electromagnetic brake Figure 1.3, designed to stop and hold the elevator car stationary when the winch engine is not running.

Figure 1.3 Brake with electromagnets ML-1

l-electromagnet; 2 - lever; 3-block;- 4-overlay; 5- spring; 6 - release lever, 7 - nut; 8 - adjusting bolt; 9 - nut, 10 - cup; 11 - axle.

Cabin

The elevator cabin is suspended on traction ropes in the shaft and is designed to transport passengers.

The elevator cabin (Fig. 1.4) consists of an upper beam 1, a ceiling 2, a floor 3, cabin door leaves 4, a door drive 5 and a bottom beam 6. Safety guards, a cabin suspension, and shoes are installed on the beams.

The ceiling is the top part of the cabin. On the ceiling there are lamps and a box with terminal blocks for connecting wires, as well as a button for releasing the shaft doors, which, when pressed, allows the cabin to move in inspection mode.

Natural ventilation is provided through vents in the cab.

Figure 1.4 Cabin

The suspension (Fig. 1.5) is designed for attaching ropes to the cabin. Each rope is passed through a wedge clip 17, after bending around the wedge 16, the rope is fastened to its load-bearing part with a clamp 18. The clip is connected by an axis to the upper balancer 15, which is connected through the rod 9 to the lower balancer 13, the weight of the cabin through the upper beam, the shock absorber 12, the rod 11 , attached to the lower balancer, rods 9, upper balancers 15 and clips 17 transmit it to the ropes.

To control the tension of the ropes, a frame 14 and a switch 8 for controlling the slack of the ropes are installed on the beam. If one, two or three ropes are weakened or broken, the balancer 15 presses the frame 14, which acts on the switch 8, the electric motor is turned off, which leads to the cabin stopping. If all traction ropes break or weaken at the same time, tie ring 1, lowering through rod 2, pin 6 presses on frame 14, which acts on the switch. The frame is returned to its original position by spring 10, the pin by spring 5.

Figure 1.5 Cabin suspension

Catchers

Catchers (Fig. 1.6) are designed to stop and hold the cabin on the guides when the downward speed of the cabin increases.

Catchers - wedge, spring-loaded, smooth braking. Catchers are designed for working together with a speed limiter and are one of the critical components ensuring safe use of the elevator.

Figure 1.6. Catcher mechanism

The catchers consist of four jamming mechanisms of the same design and a mechanism for activating the catchers. The jamming mechanism consists of a brake shoe 12 moving vertically relative to the block 9, approaching the guide. The main elements of the brake shoe are the spring 11 and the wedge 10, installed in the housing. The activation mechanism consists of two wedge levers 3 mounted on shafts 8, the shafts are connected to each other by a rod 4 on which a return spring and adjusting nuts are located, lever 2 connects the speed limiter with a rope to the mechanism for engaging the safety catchers. When the speed limiter is activated, the movement of the rope fixed to the lever of the catcher activation mechanism. At further movement cabin down, lever 2 turns shaft 8, and through rod 4, shaft 8 also turns, rotation of the shafts is accompanied by rotation of levers 3, which turn on the jamming mechanism.

Figure 1.7 Catchers

When the brake shoe moves upward, after it touches the working surface of the guide head, the spring is deformed, which provides the necessary braking force when tightening the wedge, the movement of the brake shoe is limited by the adjusting nut 15, due to which the clamping force of the guide head and, accordingly, the braking force during braking do not change, after the energy of the moving cabin is extinguished, it stops, the bar on the rod 4 presses on the roller of the switch 5, the contacts of which open and supply signal to turn off the winch motor.

To remove the cab from the catchers, it is necessary to raise the cab, the brake shoes are lowered under the influence of their own weight and springs 6 and the catcher mechanisms return to their original position.

Door drive and cab door

The drive with the cabin door beam is designed for automatic opening and closing of centrally opening cabin doors (DC).

The drive with the DC beam guarantees safe use of the cabin. The shutter positions (opened or closed) are controlled by electrical switches.

Composition, structure and operation

The drive with the DC beam (Fig. 1.8) consists of: beam 1; gearbox 2; right carriage 3; left carriage 4; layering 5; rope 6; switch 7; lever 8; shock absorber 9; emphasis 10; ruler 11; nut 12; video 13; lever 14; cams 15, 16; switches 17, 18; microswitch 19; spring 20; video 21; pin 22; electric motor 23; emphasis 24; spring 25, clamp 26, bolt 27.

Figure 4.8 shows the state of the drive with the DC beam when the DC valves are closed.

Figure 1.8 Drive with DC beam

1-beam; 2-reducer; 3 - right carriage; 4 - left carriage; 5- layering; 6 - rope; 7 - switch; 8 - lever; 9 - shock absorber; 10 - emphasis; 11 - ruler; 12-nut; 13-roller; 14-lever; 15,16-cam; 17, 18 - switches; 19 - microswitch; 20-spring; 21 - block; 22-pin; 23 - electric motor; 24 - stop; 25 - spring; 26-lighten; 27 – bolt.

When the electric motor 23 is turned on, the rotation of its rotor is transmitted through the V-belt drive to the worm shaft of the gearbox 2 and through the worm gear to the low-speed shaft on which the lever 14 is mounted. The lever, which has a roller 13, describes a semicircle when moving and the roller pulls the stop 10, which is rigidly fixed to right carriage 3. The right carriage 3, together with the door leaf, moves along the ruler 11, and at the same time, the rope 6 forces the left carriage 4 with the leaf to move. The cabin door leaves open and close synchronously.

The angle of rotation of lever 14 depends on the installation of cams 15 and 16, which must be set so that when the doors are open, lever 14 stops in a horizontal position with a tolerance of ±5 mm, and when closed, so that pin 22 is in the middle of the notch on stop 10. Fit lever 14 on shock absorbers 9 is not allowed in normal drive operation mode. Cams 15 and 16 are rigidly fixed to the hub of lever 10 and, rotating together, right moment act on switches 17 and 18 (VKO and VKZ) and provide an impulse to turn off the electric motor 23.

The drive has a special device that switches the electric motor to reverse if there is an obstacle in the doorway when closing the door leaves. The device operates as follows: when the drive is turned on for closing, the 14" lever restrains the movement of carriages 3 and 4 with flaps, the closing of which is carried out by the force of the spring 20, and the shaft door flaps are closed under the action of a load on the right flap. If an obstacle arises in the path of movement of the flaps, they stop, but the lever continues to move. A gap is selected between the bevel of the stop 10 and the pin 22 on the lever 14; with further movement of the lever 14, the pin 22 begins to slide along the bevel E of the stop 10 (Fig. 4.8, view A), is recessed into the roller sleeve 13 and through The lever system (pin 22, rocker arm 14, lever 8) is switched by microswitch 19. Microswitch 19 gives an impulse to electric motor 23 to reverse. The door opens.

When the cabin door flaps are closed, in the maximum raised position of the lever 14, pin 22 acts as a locking device that does not allow the cabin door flaps to be moved apart. In addition, a sinking stop 24 is installed, which is an additional safety element that eliminates the possibility of opening the doors from the cabin. When evacuating a passenger from the cabin, the stop 24 is pulled back by the nut 12, the pin 22 is recessed into the sleeve of the lever 14, on which the roller 13 is mounted, the carriage 3 is pushed to open.

Adjustment of the location of carriages 3 and 4 relative to each other and the gap (5=1...2 mm between the pin 22 and the notch of the stop 10 in the closed position is carried out by loosening the tightening of the clamp 26. Volg 27 is used to adjust the gap y=0.5... 3 mm between the rocker arm 10 and the lever ring 8.

Description of the automatic door control unit

Connectors are installed in the lower part of the BUAD through which the elevator control station (SHULK, UL, etc.), electric motor 2 and tachometer 17 are connected. Four harnesses are connected to the connectors.

The first harness is the power one, connects the control station, 220 V (the control unit is powered by an alternating current network).

The second harness connects a 2.220 V x 3 phase electric motor (the BUAD supplies a three-phase voltage of 220 V to the electric motor). This harness contains a wire for grounding the CUAD of the electric motor housing.

The third and fourth harness - control, connect the control station, +24 V (BUAD control circuits are designed to use direct current with a voltage of 24 V).

The fifth harness connects the BUAD with tachometer 17 ( Feedback with actuator).

Figure 1.9 - BUAD diagram

Operation of the BUAD in accordance with the diagram

The BUAD is connected according to the above diagram, Figure X.

The door opens according to the following algorithm. A signal to open the door comes to the BUAD from the control station. The BUAD, in accordance with a given program, supplies voltage to rotate the electric motor in the direction of opening the door. The doors open. When the doors are fully opened, the BUAD compares the number of marks (number of interruptions) with those recorded in its memory and, if they match, sends a command to the XZ-5 output. The control station turns off the door opening contactor. Closing the door is similar.

A signal to close the door comes to the BUAD from the control station. The BUAD, in accordance with a given program, supplies voltage to rotate the electric motor in the direction of closing the door. The doors close and the closed position contact is activated. The BUAD issues a command via output XZ-3, the control station turns off the door closing contactor. Reverse.

A signal from the control station (24 V) is supplied to the PVM1 input of the BUAD; through a built-in relay, the signal from the PVM2 terminal is returned to the control station. If an obstacle occurs in the opening while closing the door, the electric motor 2 stops and the breaker 16 stops rotating. Analyzing the signal from tachometer 17, the BUAD breaks the contact of the built-in relay and removes the signal from the input of ХЗ-1. Next, the control station turns off the door opening contactor. After a certain time, the control station repeats the closing mode and, if the obstacle to closing is removed, the doors close. and the XZ-3 output sends a signal that the doors are completely closed and the electric motor stops.

The control station turns off the door closing contactor and turns on the door opening contactor. After a certain time, the control station repeats the closing mode and, if the obstacle to closing is eliminated, the doors close, and the XZ-3 output sends a signal that the doors are completely closed and the electric motor stops.

Setting up the BUAD

The BUAD installed on the elevator car arrives at the programmed object

To change the settings you need to test it

1. When the power is first turned on, the BUAD must perform a calibration cycle. It must measure the distance of the opening and, if it matches the one recorded earlier, the BUAD 4-25 issues the VKZ command, otherwise it is necessary to reconfigure the doorway.

All rotations of the electric motor will be carried out at low speeds.

Remove the plug on the BUAD 4-25 body;

- connect the programmer cable to BUAD 4-25 and the USNA-2 programmer;

Supply 220 V power to BUAD 4-25;

Service information (software version number) will appear on the programmer indicator;

To reset a doorway:

Press the “+” button on the front panel of the programmer - “ffiSt” will be displayed;

Press the “ENTER” button - a sound signal will sound and the dot in the fourth digit “tESt” will light up on the indicator;

Press the “RESET” button;

Apply a signal from the control station to the “Open Doors” input until the “VKO” indication appears;

Apply a signal from the control station to the “Close Doors” input until the “VKZ” indication appears;

The indicator of the USNA-2 programmer will display the number of pulses from the tachometer;

After the doors close, turn off the power to BUAD 4-25;

Wait until the BUAD 4-25 indication goes off;

Disconnect the USNA-2 programmer cable;

Install the plug on the BUAD 4-25 body. BUAD 4-25 is ready for work.

For more detailed settings, you must use the EMRC manual. 421243.074 - 25 RE at BUAD 4-25 and the management of the EMRC. 421243.200 - 04 RE for USNA -2, which are supplied with each elevator and are included in the album with technical documentation.

Mine door

The shaft doors (DS) are designed for safe use of the elevator and to prevent access to the elevator shaft.

DSh (Fig. 1.10) - sliding, double-leaf, central opening, automatic, driven by the cab door drive.

Composition, structure and operation of the shaft door

DSh (Fig. 1.10) consists of: beam 1, doors 2 and 3, frame 4, casing 5, apron 6, ruler 7, carriages 8 and 9, lock 10, lock roller 11, lock stop 12, control unit 13, stop 14 , weight 15, corner 16, bracket 17, threshold 18.

Beam 1, threshold 18 and apron 6 are installed on frame 4.

A ruler 7 is attached to the beam 1, on which carriages 8 and 9 are mounted, with doors 2 and 3 attached to their studs. Each carriage moves along the ruler 7 on rollers, which eliminate the possibility of lifting and moving the carriages from the ruler. The lower rollers (counter rollers) can move relative to the carriage body along inclined grooves, which allows you to adjust the gap between the ruler and the rollers. The weight 15 in door 2 serves for emergency automatic closing of the doors in the absence of a cabin at a given stop.

When the cabin is located in the stopping zone, the rollers 11 of the locks 10 of the shaft door are located between the cheeks of the driver of the cabin doors. At the moment the carriages begin to move, the doors of the cabin unlock the locks of the shaft door to open the lift, then the doors of the cabin and the shaft open together. The rebate between the doors 2 and 3 is adjusted by stops 14 mounted on carriages 8 to 9.

Figure 1.10 Shaft door

1 - beam; 2 and 3 - doors; 4 - frame; 5 - casing; 6 - apron; 7 - ruler; 8 and 9 - carriages; 10 - lock; 11 - lock roller; 12 - lock stop; 13 - control unit; 14 - emphasis; 15 - cargo; 16 - corner; 17 - bracket; 18 – threshold.

The position of the shaft door shown in Fig. 1.7 corresponds to the position of closed and locked doors. In the closed position, the shaft door is locked with lock 10. Each carriage has its own lock. The stop 12 for the latch of the lock 10 is the base of the control unit 13, fixed to the beam 1. The closing of the sashes, the rebate of the sashes and the locking of the locks are controlled by microswitches of the control unit through the rocker arms (see Fig. 4.10, callout A, designated K). When the lock 10 is unlocked, the arm of the rocker arm, with which it rested on the lock latch, moves down and thereby releases the microswitch pusher in the control unit, the contacts of which break the control circuit, excluding the start of the cabin when the lock is unlocked on any carriage.

When the cabin door flaps (DC) move to close, the drive arms together with the rollers of the carriage locks of the shaft door also move to close, the DS flaps move to close under the action of load 15. The load 15, located in the chute of the sash 2, is connected to a rope that goes around the roller is on the left carriage 8, and the second end of the rope is attached to the right carriage 9 (see Fig. 1.9, callout A). In this case, the full vertical movement of the load is equal to the width of the door opening plus 16 mm. With the sash fully open, the upper cut of the load 15 should be at a distance of 1004-150 mm to the upper cross member of the sash 2. The load 15 is inserted into the groove on the sash 8 through the lower cross member with the sash 2 shoe removed, its rope is pulled through the upper cross member.

Weight 15 ensures automatic closing of the door shutters in the absence of a cabin on a given floor.

The doors 2 and 3 are fixed at the top on the studs of the carriages 8 and 9, and at the bottom they slide with their shoes along the guide formed by the lower cross member of the frame 4 and the threshold 18.

Counterweight and speed limiter

Counterweight. Shoes. Speed ​​limiter. The counterweight is designed to balance the weight of the cab and half the rated load capacity. The counterweight is located in the elevator shaft and is suspended on traction ropes using a suspension. The counterweight consists of a frame in which the loads are placed. The frame consists of upper and lower beams and risers.

In the middle part the frame is fastened with a tie. Shoes are installed on the upper and lower beams.

The shoes are designed to stabilize the cabin and counterweight on the guides in the shaft.

The shoes are installed on the cabin and secured in pairs to the top beam and the cabin floor frame. A device for lubricating the guides is installed on the shoes of the upper beam of the cabin and the counterweight.

The guides are installed in the elevator shaft along the entire path of movement of the cabin and counterweight and are fixed to the construction part of the shaft. The guides prevent rotation of the cabin and counterweight along vertical axes, as well as rocking of the cabin and counterweight when moving. In addition, the cabin guides absorb loads when landing the cabin on the catchers.

The cabin guides are made of a special T-shaped profile. The counterweight guides are made of angle steel. For elevators intended to operate in areas with seismicity from 7 to 9 points, the counterweight guides are made identical to the cabin guides.

A speed limiter rope tensioner is installed on one of the cabin guides.

The speed limiter rope tensioning device consists of a bracket 8 on which a lever 9 with a block 10 and a load 11 is hinged on a pin. The block is suspended on a loop of the speed limiter rope. The weight serves to tension the rope. The angle of inclination of lever 9 is controlled by switch 12. When lever 9 is deflected at an angle of more than 33 degrees, the tap affects switch 12, breaking the elevator control circuit.

The speed limiter device is shown in Fig. 1.10. Two weights 4 are hinged on the pulley axis. When the pulley rotates, the centrifugal forces arising in the weights tend to separate the ends. At nominal pulley speeds, the centrifugal action is balanced by the force of the spring 6 installed on the rod connecting the loads. When the number of pulley revolutions increases by 15 - 40% of the nominal value, the centrifugal forces overcome the resistance of the spring, the ends of the weights diverge and engage with the stops 2 of the housing 7. The rotation of the pulley stops and at the same time the speed limiter rope stops moving, and as the cabin continues to move down, the rope includes catchers. To check the traction capacity of the working pulley groove, it is necessary to stop the pulley at normal speed of movement of the cabin by pressing the movable stop 5. When laying the rope in the groove of the small (test) pulley, an increase in speed of approximately 40% is simulated on the limiter. This makes it possible to check the operation of the speed limiter and safety devices at the nominal speed of the cab. The limit switch (Fig. 1.11) is designed to turn off the elevator in the event of the cabin moving to extreme positions limited by the level of the upper and lower floors.

The limit switch is mounted on a stand 14 and is actuated by two clamps 15 and 16, attached to the speed limiter rope. When the cabin moves to extreme positions, the clamps turn the lever 18, which, with the help of a bracket 19, acts on the switch, which causes the cabin to stop.

Figure 1.11 Speed ​​limiter

Shunts and switches are installed both on the cabin and in the elevator shaft at different heights. They are designed to ensure automatic operation of the elevator. When the shunt interacts with the switch, a command is issued to the elevator control circuit to change the speed of the car or to stop it.

The pit is located below the level of the lower stop mark. It contains the cabin buffers and counterweight (Fig. 1.12). At a cabin speed of 1.6 m/s, hydraulic cabin and counterweight buffers are installed instead of spring ones.

Figure 1.12 Hydraulic buffer

1 - shock absorber; 2 - rod; 3 - sleeve; 4 - support; 5- spring; 6 - limit switch; 7-bar; B-6uksa;9-guide; 10-wedge; 11 - piston; 12-guide; 13-cork; 14-cuff; 15-wiper; 16-screw; 17 – locking ring, 18 – sealing ring.

Modernization tasks

The goal of the modernization is to improve the smoothness of acceleration and smoothness braking and increasing speed by replacing a two-speed motor with a single-speed motor and installing a frequency converter..

The first versions of the elevator appeared in ancient Egypt. In those days, most elevators, powered by people or animals, were used in construction. Starting from the 17th-18th centuries, lifting mechanisms migrated to the palaces of crowned heads.

You and I are luckier: an elevator is not a luxury or rarity, but a necessity. According to statistics, there are more than 500,000 elevators in Russia. Some of them are gradually being replaced by new types of machines.

The design of the elevator depends on its type and purpose. Experts divide elevators into 3 types: hydraulic, pneumatic and “classical”, that is, with electrically driven. Let's take a look at how a traditional passenger elevator works.

Operating principle of the elevator

The elevator cabin is mounted on durable steel cables, wrapping around a grooved wheel, or pulley. This drive mechanism is needed in order to redistribute force.

The signals are transmitted via an electrical cable to the engine room, which is located at the top of the shaft. To be precise, the cable connects the control cabinet below and the keypad in the cab.

The cables at one end have counterweights necessary to balance the elevator car. Once the engine starts, the weights are lowered, raising the platform (and vice versa). No need to lift the cab high power, since the main load goes directly to the counterweights.

What determines the lifting capacity of an elevator? The weight that the platform can lift depends on the power of the cable and the strength of its adhesion to the pulley. The equipment of freight elevators differs from passenger cars, first of all, by the fact that there is another cable here, that is, the drive wheel is wrapped twice.

Geared Elevators and Worm Gear

Lifts that are equipped with lifting machines may have a gearbox. If the elevator circuit provides a mechanism responsible for transmitting and converting torque, then we are talking about the so-called “worm gear”.

This means that the movement of the shaft is converted into the movement of the wheel. Mechanisms with a translational-rotational operating principle are used in cases where the loads being lifted are small and the distance covered by the platform is short. Typically, the installation of elevators of this type is ordered for cottages, small hotels, boarding houses, and so on.

What is the difference between a lift and an elevator?

Few people know that a lift differs from an elevator only in the design of its doors. So, the elevator has double doors, and the elevator has single doors.

Passengers sometimes complain that elevator doors take too long or too quickly to close. This means that the time relay is not configured correctly.

Next, let's talk about security. Elevator equipment includes a brake, which must fix the counterweights and the cabin. If the cables become loose or break, the platform should be blocked.

IN emergency situation catchers connected by ropes to a limiting device at the bottom of the shaft, in the elevator pit, are activated. The catchers also replace the brake if the cab exceeds the set speed.

What does the elevator look like schematically?

If you find elevator diagrams on the Internet, the drawings will include the following elements:

• Stretching device;
• Counterweight buffer;
• Cabin buffer;
• Guide support;
• Ladder in the pit;
• Cabin (platform);
• Cabin guides;
• Counterweight;
• Call panel;
• Mine door;
• OS rope and traction ropes;
• Counterweight guides;
• Speed ​​limiter, winch (at the control station).

About the design of hydraulic and pneumatic elevators

Hydraulic elevators appeared in the 19th century. The principle of operation of such a machine is that there is a piston in a vertical cylinder, which is driven by hydraulic oil pumped by the pump. As a result, the elevator cabin is raised by cables.

The speed of hydraulic elevators, as already mentioned, is low. Also the disadvantages include high level noise and high cost. Typically, such mechanisms are installed in low-rise buildings. If we talk about the advantages of these lifting machines, then it is worth mentioning the smoothness of the lift.

If we evaluate the equipment of hydraulic elevators from the point of view of specialists, and not passengers, then we will talk about ease of installation. You can install an elevator if there is only one load-bearing wall.

Finally, let's talk about pneumatic elevators, which are also called airlifts. The design of such an elevator eliminates blocks, cables and pistons. In addition, there is no need to build an engine room.

The airlift moves due to the pressure difference created by the turbine and Vacuum pump. The platform lowers due to gravity.