Chinese name: traction machine mbth: traction machine uses: elevator traction machine is the power equipment alias of elevator: traction ratio of elevator main machine: usually 2: 1 and 1: 1 classification: introduction, classification, working principle, installation and influencing factors of permanent magnet synchronous traction machine and worm gear traction machine. Applications, brakes, reducers, couplings, other machines, traction motors, traction wheels, traction wire ropes, permanent magnet traction machines, relevant information, working conditions, installation, lubrication, inspection, maintenance and brief introduction. 1. Classification by deceleration mode 1. Gear traction machine: the power of the traction device is transmitted to the traction machine on the traction wheel through the intermediate reducer, in which the traction ratio is usually 35: 2. If the motor power of the traction machine is transferred to the traction wheel through the reduction box, it is called a gear traction machine, which is generally used for middle and low speed elevators below 2.5 m/s. Gearless traction machine: the power of traction device is directly transmitted to traction wheel without intermediate reducer. In the past, this kind of traction machine was mostly powered by DC motor, and China has developed an AC permanent magnet synchronous gearless traction machine with independent intellectual property rights. Traction ratio is usually 2: 1 and 1: 1. The load is 320kg~2000kg, and the step speed is 0.3 m/s ~ 4.00 m/s. If the power of the motor is directly transmitted to the traction sheave without passing through the reduction box, it is called gearless traction machine, which is generally used for high-speed elevators and ultra-high-speed elevators above 2.5 m/s. Flexible transmission mechanism traction machine 2. According to the classification of drive motor 1, DC traction machines can be divided into DC toothed traction machines and DC toothless traction machines. 2. AC traction machine can be divided into AC toothed traction machine, AC toothless traction machine and permanent magnet traction machine. Among them, AC traction machine can be subdivided into worm gear pair traction machine, cylindrical gear pair traction machine, planetary gear pair traction machine and others. 3. Classification by purpose. Two-speed passenger and freight elevator traction machine 1 set. 4. ⒉VVVF passenger elevator traction machine 1. Grocery tractor 1. Tractor without machine room 1. Vehicle elevator traction machine 4. Classification by speed 1. Low speed traction machine (1. < 1m/s) 1。 Medium speed traction machine (fast traction machine) (ν = 1m/s ~ 2m. s) 1。 High-speed traction machine (argument = 2m/s ~ 5m/s)1set. Ultra-high speed traction machine (argument = 2m/s ~ 5m/s) 5m/s) 5. Classification by structural form. Working principle of horizontal traction machine 1. The traction drive relationship of the traction elevator is as shown in the figure. The motor, reducer and brake installed in the machine room constitute the traction machine, which is the driving force of traction. One end of the traction wire rope is connected to the car through the traction sheave, and the other end is connected to the counterweight device. In order to make the car and counterweight in the hoistway run along the guide rail in the hoistway without rubbing against each other, a guide wheel is placed on the traction machine to separate them. The gravity of the car and counterweight makes the traction wire rope tightly pressed in the traction sheave groove, resulting in friction. In this way, the rotation of the motor drives the traction wheel to rotate, drives the wire rope, drags the car, and moves relative to the counterweight. That is, the car rises and the counterweight falls; The counterweight goes up and the car goes down. Then, the car moves up and down along the guide rail in the hoistway, and the elevator performs the vertical transportation task. Traction drive relationship of traction elevator The relative movement between the car and the counterweight is realized by the friction between the traction rope and the traction sheave. This force is called traction or driving force. In operation, the load, position and running direction of the elevator car are changing. In order to make the elevator have enough traction under various conditions, the national standard GB 7588—2003 "Safety Code for Elevator Manufacture and Installation" stipulates that the traction conditions must meet the following requirements: t 1/T2≤efα:t 1/T2- the car with rated load of 125% is located at the lowest floor station and empty car. C 1—— the coefficient related to acceleration and deceleration of elevator and special installation, generally called power coefficient C2—— the influence coefficient of cross-section change of traction sheave groove caused by wear (semicircular or notched groove C2= 1, V-shaped groove C2 = 1.2). In efα, f is the equivalent friction coefficient of the traction rope in the traction rope groove, and α is the wrap angle of the traction rope on the traction sheave. Efα is called the traction coefficient. It defines the ratio of T 1/T2. The larger efα is, the larger the allowable values of T 1/T2 and T 1-T2 are, which means the greater the traction capacity of the elevator. Therefore, the traction coefficient of the elevator represents the traction capacity of the elevator. Installation and installation steps (1) When the load-bearing beam is under the floor of the machine room, a reinforced concrete base with a thickness of 250 ~ 300 mm, which is about 30mm larger than the chassis of the traction machine, is generally made, and bolts for fixing the traction machine are embedded in the base. Damping rubber pads should be placed under the concrete base and above the bearing beam, and the traction machine should be fixed on the concrete base. The concrete base and the traction machine are fixed together through a pressure plate and a baffle. (2) When the bearing beam is higher than the floor of the machine room, the steel base of the traction machine chassis can be bolted with the bearing beam into a whole. If vibration reduction is needed, a vibration reduction device should be made. The specific method is to make two steel plates with the same size and thickness of about 20mm as the traction machine base, and put a damping rubber pad in the middle. The upper steel plate is connected with the traction machine through bolts, and the lower steel plate is welded with the bearing beam. In order to prevent displacement, the upper steel plate and the traction machine chassis also need to be provided with pressure plates and baffles, as shown in figure 1-43. (3) When the load-bearing beam is installed on a reinforced concrete platform 600mm above the ground of the machine room, baffles and damping rubber pads should be placed on the platform, and upper and lower connecting steel plates should be installed. Fix the traction machine on the steel plate and position it with the pressure plate and baffle. (4) Correction of the installation position of the traction sheave. A horizontal lead is fixed above the traction machine, and two vertical lines suspended from this horizontal lead are aligned with the center point of the car frame and the center point of the counterweight on the floor, and then the pitch circle diameter of the traction sheave is calculated according to the center of the traction rope, and another vertical line is correspondingly suspended on the horizontal lead. Finally, these standard lines are used to calibrate the traction machine. Deviation of technical requirements for installation of traction sheave position (1): the front and rear (towards counterweight) directions shall not exceed 2mm, and the left and right directions shall not exceed1mm.. (2) The lead sag error of the traction sheave is not more than 2.0mm; (3) The parallelism error between the traction sheave and the guide sheave or the rewinding sheave is not more than 65438 0mm. The balance coefficient of the influencing factor is that the gravity of the car and the counterweight generates traction on the rope groove of the traction sheave through the traction rope, and the counterweight is the necessary condition for the friction between the traction rope and the rope groove of the traction sheave. With it, it is easy to keep the balance between the weight of the car and the weight of the payload, and it can also reduce the power consumption of the transmission device when the elevator is running. Therefore, the counterweight, also called balance weight, is hung at the other end of the traction sheave relative to the car to balance the weight of the car. When the car side weight is equal to the counterweight side weight, T 1=T2. If the weight of wire rope is not considered, the traction machine can run easily only by overcoming all kinds of friction resistance. But in fact, the weight of the car changes with the change of goods (passengers), so it is impossible for the fixed counterweight to completely balance the weight of the car under various loads. Therefore, the matching of weight will directly affect the traction and transmission power. In order to make the absolute value of the load torque of the elevator basically equal under the condition of full load and no load, the national standard stipulates that the balance coefficient K = 0.4 ~ 0.5, that is, the counterweight balances 40% ~ 50% of the rated load. Therefore, the total weight of the counterweight side should be equal to the car weight plus 0.4 ~ 0.5 times the rated load. This 0.4 ~ 0.5 is the balance coefficient. When k = 0.5, the load torque of the elevator is zero at half load. The car and counterweight are completely balanced, and the elevator is in the best working condition. However, when the elevator load changes from no-load (no-load) to rated load (full load), the torque reflected on the traction sheave changes only by 50%, which reduces the energy consumption and the burden of the traction machine. Equivalent friction coefficient f and rope groove shape When the traction rope is in contact with the rope grooves of traction wheels with different shapes, the friction is different, and the greater the friction, the greater the traction. From the point of view of use, there are several kinds: semi-circular groove, V-shaped groove and semi-circular groove with cut. The semicircular groove f is the smallest and is used to rewind the traction sheave. V-shaped wheel F is the largest, and it increases with the decrease of opening angle, but at the same time, the wear also increases, and the traction rope is stuck. With wear, it tends to be semi-circular groove. Semi-circular notch groove F is between the two, which basically does not change with wear, so it is widely used. The lubrication of steel wire rope in rope groove also directly affects the friction coefficient. Only the oil core in the rope can be slightly lubricated, and no lubricating oil can be coated outside the rope, so as to avoid reducing the friction coefficient, causing slippage and reducing traction. The wrap angle of the traction rope on the traction wheel refers to the radian of the traction wire rope passing through the rope groove. It means that the greater the wrap angle, the greater the friction force, that is, the traction force, which improves the safety of the elevator. There are two main methods to increase the wrap angle. One is to increase the wrap angle to 180 by using the traction ratio of 2: 1. The other is compound winding type (α 1+α2). The winding mode of traction wire rope of traction machine elevator mainly depends on traction conditions, rated load and rated speed. There are many kinds. These winding modes can also be regarded as different transmission modes, and different winding modes have different transmission speed ratios, also called traction ratio, which is the ratio of the circular linear speed of the traction sheave pitch to the running speed of the car when the elevator is running. The winding times of wire rope on traction sheave can be divided into single winding and rewinding. In single winding, the steel wire rope bypasses the traction sheave only once, and the wrapping angle is less than or equal to 180; in rewinding, the steel wire rope bypasses the traction sheave twice, and the wrapping angle is greater than 180. The elevator using this brake adopts electromechanical friction normally closed brake. The so-called normally closed braking refers to braking when the machine is not working and releasing the braking when the machine is running. When the elevator brakes, under the action of mechanical force, the friction between the braking belt and the braking wheel produces braking torque. When the elevator is running, the brake is released by electromagnetic force, so it is also called electromagnetic brake. According to the working current of the coil that generates electromagnetic force, the brake can be divided into AC electromagnetic brake and DC electromagnetic brake. Because of its stability, small size and reliable operation, DC electromagnetic brake is mainly used in elevators. Therefore, the full name of this brake is normally closed DC electromagnetic brake. Traction machine brake is the basic device to ensure the safe operation of elevator. The requirements for elevator brakes are: enough braking torque can be generated, and the braking torque should be independent of the steering of traction machine; When braking, there should be no additional load on the traction motor shaft and the gearbox worm shaft; When the brake is released or braked, it should be stable and can meet the working requirements of frequent starting and braking; Brake should have sufficient rigidity and strength; Braking has high wear resistance and heat resistance; Simple and compact structure, easy to adjust; There should be a manual brake release device; Low noise. Basic requirements of brake function: ① When the elevator power supply is cut off or the control circuit power supply is cut off, the brake can brake immediately. ② When the car is fully loaded 125% of the rated load and running at the rated speed, the brake should be able to stop the traction machine. (3) When the elevator is in normal operation, the brake should be kept loose under the condition of continuous power supply; After disconnecting the brake release circuit, the elevator should brake effectively without extra delay. (4) In order to cut off the current of the brake, at least two independent electrical devices should be used. When the elevator stops, if the main contact of one of the contactors is not opened, the elevator should be prevented from running again when the running direction changes at the latest. ⑤ The elevator traction machine equipped with manual turning handwheel should be able to release the brake manually and need a continuous force to keep it released. Structure and working principle of the brake: When the elevator is stationary, no current flows in the coils of the traction motor and the electromagnetic brake. At this time, because there is no attraction between the electromagnetic cores, the brake pad tightly holds the brake wheel under the pressure of the brake spring to ensure that the motor does not rotate; At the moment when the traction motor turns on, the coil in the brake electromagnet is energized at the same time, and the electromagnetic iron core is attracted by rapid magnetization, which drives the brake arm to force its brake spring, the brake shoe opens and is completely separated from the brake wheel, and the elevator runs; When the elevator car reaches the required stop position, the traction motor is powered off and the coil in the brake electromagnet is powered off. The magnetic force in the electromagnetic iron core quickly disappears, and the iron core is reset by the brake arm under the action of the brake spring, so that the brake shoe hugs the brake wheel again, and the elevator stops working. Reducer Reducer is used for gear-driven traction machine. Installed between the rotating shaft of the traction motor and the rotating shaft of the traction wheel. Types and characteristics of reducer (box): The worm reducer consists of a worm with a driving shaft and a worm wheel with a driven shaft, and the worm wheel is installed on the bearing of the housing. Its speed ratio can be in the range of 18 ~ 120, and the number of teeth of the worm wheel is not less than 30. Its efficiency is not as good as that of gear reducer, but it is compact in structure and small in overall size. The characteristics of worm gear reducer are: large transmission ratio, low noise, stable transmission and low reaction efficiency, and the worm wheel has certain self-locking ability when driving the worm; It can increase the braking torque of the elevator and increase the safety when the elevator stops. Coupling The coupling is a device that connects the shaft of the traction motor and the worm shaft of the reducer. It is used to transfer torque from one shaft to the other, and it is also the braking wheel of the braking device. The joint between the shaft end of traction motor and the shaft end of reducer worm. The motor shaft and the reducer worm shaft are on the same axis. When the motor rotates, it drives the worm shaft to rotate, but they are two different parts. They need to be connected on the same axis by appropriate methods to maintain a certain degree of coaxiality. Type of coupling: rigid coupling: for the structure with sliding bearing on the worm shaft, rigid coupling is generally used, because the fit gap between the shaft and the bearing is large at this time, and rigid coupling is helpful for the stable rotation of the worm shaft. Rigid coupling requires a high concentricity between the two shafts, and the concentricity after connection should not be greater than 0.02 mm Elastic coupling: Because the rubber block in the coupling will be elastically deformed when transmitting torque, the concentricity between the motor shaft and the worm shaft can be automatically adjusted within a certain range, so it is allowed to have a large concentricity (tolerance is 0. 1mm) during installation, which is convenient for installation and maintenance. At the same time, the elastic coupling can slow down the vibration in the transmission process. Traction motors of other machines The traction motors of elevators are AC motors and DC motors, and the traction motors are the power source to drive the elevator to run up and down. Elevator is a typical potential load. According to the working nature of the elevator, the elevator traction motor should have the following characteristics: 1, and can be started and braked frequently: the number of times of starting and braking of the elevator per hour often exceeds 100, and the highest can reach 180 ~ 240 times per hour. Therefore, the elevator motor should be able to start and brake frequently, and its working mode is intermittent periodic working system. 2. Small starting current: In the design and manufacture of squirrel-cage rotor of AC motor for elevator, although the conductor bar is still made of low resistance coefficient material, the rotor short-circuit ring is made of high resistance coefficient material, which improves the resistance of rotor winding. In this way, on the one hand, the starting current is reduced to about 2.5 ~ 3.5 times of the rated current, thus increasing the allowable starting times per hour; On the other hand, because only the short-circuit end ring resistance of the rotor is large, it is beneficial to direct heat dissipation, and the comprehensive effect reduces the temperature rise of the motor. But also ensure sufficient starting torque, which is generally about 2.5 times of the rated torque. However, compared with ordinary AC motor, its mechanical characteristics, hardness and efficiency are all decreased, and the slip rate is also increased to 0. 1 ~ 0.2. The mechanical characteristics become soft, which increases the speed regulation range, and the motor will not burn out when working under the locking torque. 3. Low noise of motor operation: In order to reduce the noise of motor operation, sliding bearings are adopted. In addition, the effective outer diameter of stator core should be appropriately increased, and the shape of stator core punching sheet should be reasonably treated. Traction sheave Traction sheave is the sheave on the traction machine, also known as traction sheave or rope drive sheave. It is a device for elevator to transmit traction power, which uses the friction between traction wire rope and rope groove of traction wheel rim to transmit power, and is installed on the worm shaft in the reducer. In the case of gearless traction machine, it is installed on the side of the brake and is on the same axis as the motor shaft and brake shaft. (1) Material and structural requirements of the traction sheave ① Material and technological requirements: As the traction sheave bears all static and dynamic loads of the car, load, counterweight and other devices, it is required that the traction sheave has high strength, good toughness, wear resistance and impact resistance, so the material is QT60-2 ductile iron. In order to reduce the wear of the traction wire rope in the rope groove of the traction sheave, in addition to selecting the appropriate rope groove type, the roughness and hardness of the working surface of the rope groove should also be reasonably required. ② Diameter of traction sheave: the diameter of traction sheave is 40 times larger than the diameter of steel wire rope. In practice, it is generally 45 to 55 times, and sometimes it is more than 60 times. Because the reduction ratio of the reducer is increased in order to reduce the volume increase of the traction machine, its diameter should be appropriate. ③ Structure of the traction wheel: the whole traction wheel is divided into two parts, the middle part is a wheel barrel (drum), the outer part is made into a rim rope groove and cut on the rim, and the outer rim is sleeved on the inner wheel barrel and connected together by hinge bolts to form an integral traction wheel. The shaft of the traction wheel is the worm gear shaft in the reducer. (2) The shape of the rope groove of the traction sheave: The traction of the elevator running in the old area of the traction bow is generated by the friction between the traction sheave and the rope groove of the traction sheave. Traction wire rope Traction wire rope is also called traction rope. The elevator special steel wire rope connects the car and the counterweight, and the car is driven by the traction machine to lift. It carries the total weight of the car, counterweight and rated load. The traction machine passes through the traction wheel and guide wheel in the machine room, one end of which is connected with the car and the other end is connected with the counterweight device. The structure and material requirements of traction wire rope are generally round strand structure, which is mainly composed of steel wire, strand and core. Wire rope strands are twisted by several steel wires, which is the basic strength unit of wire rope; The more strands of steel wire rope with the same diameter, the higher the fatigue strength. Generally, elevators use 6 strands and 8 strands. The rope core is a flexible mandrel formed by winding rope strands, usually made of sisal fiber or synthetic fiber of polyolefin (polypropylene or polyethylene), which can support and fix the rope and store lubricant. The steel wire in the wire rope is made of high-quality steel with carbon content of 0.4% ~ 1%. In order to prevent brittleness, the content of impurities such as sulfur and phosphorus in the material should not be greater than 0.035%. The replacement standard of steel wire rope can generally be considered from the following four aspects: a large number of broken wires in steel wire rope. Wear occurs and develops at the same time as wire rope fracture. Surface and internal corrosion, especially internal corrosion, can be checked by magnetic flaw detector. Wire ropes have been used for quite a long time. Of course, we can't generalize by frequency of use. The general safety period is at least one year. If it takes three to five years, it is worth considering. To determine the time correctly, we need to analyze and judge from the records of regular inspection. The broken wires are evenly distributed in the strands. The maximum number of broken wires in a lay length exceeds 32 (accounting for about 20% of the total number of wire ropes). Broken wires are concentrated in one or two strands. The maximum number of broken wires in a lay length is greater than 16 (about 10% of the total number of wire ropes). The diameter of the worn traction rope is less than or equal to 90% of the nominal diameter of the original wire rope. The steel wire on the surface of the traction rope is seriously worn or corroded. Permanent magnet traction machine 1, high efficiency and energy saving, good dynamic performance of transmission system: multi-pole low-speed direct-drive permanent magnet synchronous traction machine is adopted, and there is no need for a huge worm gear reducer with mechanical transmission efficiency of only about 70%; Compared with induction motor, it does not need to draw reactive current from the power grid, so the power factor is high; Because there is no excitation winding, no excitation loss and little heating, there is no need for a fan, no wind friction and high efficiency; Field-oriented vector control has the same excellent torque control characteristics as DC motor, the starting and braking currents are obviously lower than those of induction motor, and the required motor power and inverter capacity are reduced. Traction machine 2, stable operation, low noise: low-speed direct drive, so the bearing noise is low, no fan, no worm gear noise. Noise can generally be reduced by 5 ~ 10 dB, thus reducing environmental noise pollution. 3. Save building space: there is no huge reduction gear box and excitation winding, and high-performance NdFeB permanent magnet material is adopted, so the motor is small in size and light in weight, and the machine room can be reduced or not needed. 4. Long service life, safety and reliability: the motor does not need brushes and slip rings, so the service life is long, there is no oil and gas in the gearbox, and there is little environmental pollution. 5. Less operation and maintenance cost: brushless and gearbox, simple maintenance. Compared with gear traction machine, permanent magnet synchronous traction machine has the absolute advantage of energy saving and environmental protection, which has been recognized in Europe and Japan for a long time and recently discussed in China industry. In addition to the advantages that the above customers can clearly understand, in terms of safety, it provides full-time overspeed protection due to its simplified structure and rigid straight-axis braking, and uses the back electromotive force of permanent magnet motor to realize the self-locking function of worm gear and worm, providing multi-layer safety protection for elevator system and passengers. On the application level: due to the miniaturization and thinness of the permanent magnet synchronous traction machine, the arrangement of elevators and the matching with the integrated space between buildings have been greatly improved, which is believed to provide architects with more flexible design space and indirectly improve people's use function and quality in building space. Related information Working conditions: the altitude does not exceed 1000 meters. The air temperature in the machine room should be kept at 5℃ to 40℃. Ambient air is not corrosive, and the fluctuation of combustible gas supply voltage does not exceed 7% of the rated value. The deviation between the fluctuation of working frequency and the rated value shall not exceed 65438 0%. The fire-fighting equipment with good lighting in the machine room shall be installed with ordinary I-beam or channel steel, and its strength must comply with the relevant provisions of elevator standards, and the installation levelness is11000. Before tightening the bolts, the joint between the traction machine base and the installation plane must be checked with a feeler gauge to see if there is any gap. If there is any gap, it will affect the running function of the traction machine or elevator in any form. When lubricating and filling lubricating oil, the position indicated by the oil meter should be added. Too little oil will lead to lubrication difficulties, and too much oil may lead to oil leakage. When mineral oil is used, the first oil change should be carried out after the new machine runs for about 400 hours, and if synthetic oil is used, it should be carried out after about 700 hours. In the future, according to the running situation of the traction machine, replace the mineral oil every 2000-3000 hours (no longer than12-65438+August), and replace the synthetic oil every 3000-4000 hours (no longer than 24-36 months). Check whether the lubricating oil is added to the oil mark position and release the brake manually. Turn the car manually to see. Connect the wiring flexibly as required and start running (this work must be carried out 20 minutes after refueling, otherwise the bearing will be easily damaged). Check whether the traction machine is running normally (especially emergency noise and vibration). The external surface of the traction machine should be kept clean to prevent contamination. Clean cotton silk should be regularly used to wipe the working surfaces of the brake wheel and traction wheel to check the working condition of the brake. If necessary, it should be adjusted and replaced in time, and pay attention to the wear of the traction wheel when the electromagnetic coil is less than 90k. Carry out regular maintenance according to the instructions on the use and maintenance of the traction machine.