When a fundamentally new family of ZIL-130 trucks with a modern design and a powerful 8-cylinder engine appeared in the early 60s, a new all-terrain vehicle ZIL-131 was developed on its basis, designed to replace the ZIL-157. However, for a number of reasons, the start of production was delayed, and mass production began only in 1967. However, it remained on the ZiL assembly line until the early 90s (later it was assembled in the Urals). The car turned out to be very successful.
The ZIL-130 cabin, with an advanced design for that time, in a military version with flat wings and a modified lining, still does not look outdated. The ZIL-131 very successfully combines elegance and rationalism, simplicity of design and modern technical solutions. This wonderful car deserves to talk about it in more detail. Since the ZIL-131 was developed on the basis of the ZIL-130, its main components and assemblies (engine, clutch, gearbox, steering, brake system elements, cabin) are unified with it.
Of course, these units are not absolutely identical; they have characteristic features due to specific operating conditions. The ZIL-131 engine is adapted to operate with significant longitudinal and transverse rolls. For this purpose, there is a recess in the crankcase in which there is a stationary oil receiver. It is possible to turn off the crankcase ventilation in order to create excess pressure in the crankcase to prevent water from entering the engine when wading. To make fording easier, the fan and water pump drives are separated, which allows you to turn off the fan by removing the belt. The water pump continues to operate.
The power steering pump and compressor also remain on. The radiator cooling area has been increased. The possibility of installing a compensation (expansion) tank was also provided. In this case, the valves, usually installed in the radiator cap, were located in the tank cap. When a car storms a water obstacle, the engine exhaust manifold, which has the highest temperature, cools sharply. In order to avoid its destruction, a composite exhaust manifold was installed on the ZIL-131 engine.
Another innovation is that the ZIL-131 uses a foam-oil air filter with three-stage air purification. It purifies the air much better when driving along dusty steppe roads, as well as in deserts. The brake compressor also receives air from this filter. In the power supply system, the fuel pump capacity has been increased from 140 to 180 l/min, which ensures uninterrupted operation in hot weather, when vapor-air locks may form in the system. The fuel tank plugs are made blind, without valves.
And the valves were installed in a separate sealed housing, which was connected to the atmosphere with a special tube. Its end was above the level of the maximum ford. To prevent water from entering the clutch housing, the clutch release fork is sealed. And the ventilation hole for the clutch housing when overcoming fords was closed with a special blind plug, which under normal conditions was located on the cover of the front axle gearbox housing. A special feature of the gearbox is a ventilation system through a breather with a tube, the end of which is located above the maximum ford level.
As we can see, on the ZIL-131 the closest attention was paid to the possibility of operation in extreme conditions. The electrical equipment of the car was also made with this in mind. Devices such as the starter, distributor and ignition coil are sealed. The starter uses special rubber gaskets to prevent water from entering. In general, special requirements are imposed on military vehicle starters. If the engine stalls, for example, when overcoming a ford, the starter must provide the ability to go onto land, the ignition devices are shielded, and special filters are included in the ignition coil and voltage regulator circuits.
But the most interesting part of an all-wheel drive car is the transmission. On the ZIL-131, a transmission with a middle axle was used.
At the same time, the transfer case is significantly simplified, which becomes 3-shaft. The highest gear in it is direct, which increases efficiency. The cardan transmission, which is end-to-end, is also simplified. The front axle is engaged automatically when downshifting in the transfer case is engaged; an electric pneumatic drive is used for this. If necessary, the front axle can also be switched on during direct transmission in the transfer case using a switch. The transfer case has a hatch for installing various types of power take-offs.
A separate oil pump is not required for this; the ZIL-131 main gears are double: a pair of bevel gears and a pair of spur gears. The gearbox of the middle axle, as already mentioned, is continuous. The front axle gearbox is located horizontally, the middle and rear axle gearboxes are vertical. The axis of the ZIL-131 rotary rack has a transverse inclination. The design of the remaining ZIL-131 systems is quite traditional and does not differ fundamentally from the design of similar systems of conventional trucks.
The ZIL-131 also had modifications, the most famous of which is the ZIL-131V truck tractor; there was also an ATZ-3.4-131 fuel tanker. Most of the ZIL-131 were intended for military service. Various special vehicles were created on its chassis, including a twin installation of anti-aircraft missiles, vehicles with radio equipment (for this purpose, the electrical equipment of military trucks was shielded). There was also a modification of the ZIL-131A without shielded electrical equipment.
But its most interesting modification was the ZIL-137 - an active road train with a semi-trailer driven by a tractor engine. The drive was carried out using a hydraulic lifting transmission. In addition to military service, ZIL-131 vehicles were actively used in the national economy, mainly in difficult terrain, in the taiga, for geological exploration, drilling work, in the North (there was a special northern modification of the ZIL-131S), in mountainous areas, and in swampy areas. Thanks to the centralized tire pressure control system, the car moved confidently through quicksand, loose snow, and swampy ground.
As for military service, the ZIL-131 is still in service with the armies of many countries. It can also be seen at military parades. If the ZIL-157 was an image of a rational, but extremely simple, ascetic, unpretentious car with good cross-country ability, then the ZIL-131 combined high cross-country ability with a much greater level of comfort, modern solutions and modern design. The design of the ZIL-130 cabin with developed panoramic glass, revolutionary in its time, turned out to be extremely successful. Even now, half a century later, this cabin is pleasing to the eye.
Cabin 4331, which appeared later, is clearly inferior to it in design. And the all-wheel drive truck with this cab, although similar in design to the ZIL-131, looked much less attractive. Production of ZIL-131 in the early nineties was transferred to the Ural branch of ZIL. Its chassis with a diesel engine called AMUR (Automobiles and Motors of the Urals) is still in production. Thus, the ZIL-131 surpassed its predecessor ZIL-157, which took 36 years to assemble, in terms of longevity. And the unique ZIL-131 cabin is installed at the same plant on the regular ZIL-130 chassis.
©. Photos taken from publicly available sources.
The front axle of cars of the ZIL family of models 431410 and 133GYA is controlled continuous with fork-type steering knuckles. Beam 21 of the bridge is a stamped steel I-section, with holes at the ends for connection using pins with steering knuckles. The structural difference between the axles of the ZIL models 431410 and 133GYA lies in the track width of the front wheels (due to the length of the beam): for the ZIL-431410 car - 1800 mm, for the ZIL-133GYA car - 1835 mm.
Due to the increased load on the front axle in the ZIL-133GYA car (large mass of the power unit), the cross-section of the beam on this car is 100 mm. The cross section of the beam on the ZIL-431410 car is 90 mm.
The pivot pins of the steering knuckles are fixedly fixed in the eyes of the beam with wedges that fit into a flat on the pivot pin. Taking into account the one-sided wear of the pins during operation, in order to increase their service life, two flats were made on them. The pins are located at an angle of 90°, which allows them to be rotated. Lubricated bronze bushings, pressed into the steering knuckles, ensure high durability of the unit.
The steering knuckle (trunnion) is a component of the front axle that is complex in configuration and responsible for its intended purpose; it is the basis for installing the wheel hub, brake mechanism and steering levers. The fist is made with high precision geometric dimensions for fastening mating parts.
The load from the vehicle on each front wheel is transferred to a journal bearing that has a graphitized bronze lower washer and a steel upper washer with a cork collar that protects the bearing from contamination and moisture. The required axial clearance between the beam eye and the steering knuckle is ensured by shims. If the gap is correctly selected, a 0.25 mm thick feeler gauge does not fit into it.
The thrust bolts of the steering knuckles allow you to set the required angle of rotation of the steered wheels: for the ZIL-431410 car - 34° to the right and 36° to the left, and for the ZIL-133GYA car - 36° in both directions.
Two levers are attached to the left steering knuckle in conical holes: the upper one for the longitudinal and the lower one for the transverse steering rods. There is one link for the tie rod on the right steering knuckle. Segment keys measuring 8x10 mm fix the position of the levers in the tapered holes of the steering knuckles, and the levers are secured with castle nuts. The tightening torque of the nuts should be within 300 ... 380 Nm. The nuts are secured with cotter pins to prevent them from turning. The connection of the steering arms with the transverse steering rod forms a steering linkage, which ensures coordinated rotation of the vehicle's steered wheels.
The drive of the steered wheels includes steering knuckle levers, longitudinal and transverse steering rods.
As the vehicle moves along uneven sections of the road and the steering wheels turn, the steering gear parts move relative to each other. The possibility of this movement in both vertical and horizontal planes and reliable transmission of forces ensures a hinged connection of the drive units.
The design of the hinges on all ZIL vehicles is the same, only the lengths of the rods and their configuration are different, which is due to the layout of the hinges on the vehicle.
The longitudinal steering rod is made of steel pipe measuring 35 X 6 mm. At the ends of the pipe, thickenings are made for mounting hinges in them, consisting of a ball pin and two crackers, covering the ball head of the pin with spherical surfaces, and a support with a support. Locking rivets secure the crackers from turning. The spring support is also a limiter for the movement of the internal block. The parts are secured in the pipe with a threaded plug, secured against rotation by a cotter pin 46, and protected from contamination by a cover with a gasket.
The hinge spring ensures constant clearances and forces, and also softens shocks from the steered wheels when the car is moving. A bolt, nut and cotter pin secure the rod pin in the bipod.
The unit operates normally if the requirements specified in the operating manual are met by tightening the threaded plug to the stop with a force of 40 ... 50 Nm with the obligatory unscrewing of the plug (until the cotter pin groove coincides with the holes in the rod). Compliance with this requirement ensures the required turning torque of the ball pin of no more than 30 Nm. When the plug is tightened more tightly, an additional torque will act on the ball pin, which occurs even with the slightest relative rotation of the hinge. Based on the results of bench tests of a joint with a tightly tightened plug, it was found that in this case the endurance limit of the ball pin is reduced by six times compared to the endurance limit of the joint adjusted in accordance with the operating instructions. Incorrect adjustment of the tie rod joints can lead to premature failure of the ball pins.
The tie rod for ZIL cars models 431410 and 133GYA is made of a steel pipe measuring 35 x 5 mm, and for the ZIL-131N car it is made of a steel rod with a diameter of 40 mm. At the ends of the rods there are left and right threads, onto which tips are screwed with hinges placed in them. Different thread directions ensure adjustment of the toe-in of the steered wheels by changing the total length of the rod - either by rotating the rod with the tips stationary, or by rotating the tips themselves. To rotate the tips (or pipe), it is necessary to loosen the coupling bolt that secures the tip to the rod. wheel bridge axle car
The ball pin is rigidly fixed in the conical hole of the swing arm, and the castle nut is secured against turning by a cotter pin.
The ball surface of the pin is sandwiched between two eccentric bushings. The compression force is created by a spring resting against the blind cover. The cover is secured to the tip body with three bolts. The spring eliminates the influence of joint wear on the overall operation of the unit. During operation, adjustment of the unit is not required.
The steering rod joints are lubricated through grease nipples. Sealing collars protect the hinges from the release of lubricant and contamination during operation.
In connection with the increased vehicle speeds, reliable stabilization of the steered wheels is important to ensure safety, i.e. the vehicle’s ability to stably maintain straight-line motion and return to it after a turn.
The parameters that influence the stabilization of the steered wheels are the transverse and longitudinal angles of inclination of the wheels relative to the longitudinal axis of the vehicle. These angles are ensured during the manufacture of the front axle beam by the ratio of the position of the axis of the eyelet holes for the kingpins relative to the platform for mounting springs, steering knuckles - by the geometric relationship of the axes of the holes for the kingpins and for the wheel hub. For example, the pivot holes in the beam eyes are made at an angle of 8° 15" to the spring area, the pivot holes in the steering knuckles are made at an angle of 9° 15" to the hub axis. This ensures that the pivots are tilted to the required angle (8°) and the required camber of the wheels is taken into account (at an angle D).
The transverse inclination of the kingpin determines the automatic self-return of the wheels to straight-line motion after a turn. The lateral inclination angle is 8°.
The longitudinal inclination of the king pin helps maintain the straight motion of the wheels at significant vehicle speeds. The caster angle depends on the vehicle's base and the lateral elasticity of the tires. Below are the pitch angles for various models.
During operation, the longitudinal and transverse inclinations of the kingpins are not adjusted. Their violation may occur in the event of wear of the pins and its bushings, or deformation of the beam. A worn king pin can be rotated 90° once or replaced. Worn bushings must be replaced, a deformed beam must be corrected or replaced.
One of the parameters for ensuring the best rolling conditions for the steered wheels of a car in a vertical plane is wheel toe, equal to the difference in distances (mm) between the edges of the rims in front and behind the wheel axis. This value should be positive if the rear distance is larger.
Wheel toe is adjusted during operation by changing the length of the tie rod. For cars of the ZIL-431410 family it is set within 1 ... 4 mm, for the ZIL-133GYA car - 2 ... 5 mm. The minimum value is set at the factory.
Since the steering linkage is not an absolutely rigid structure and there are gaps in the hinges, changing the loads acting in the linkage leads to a change in wheel alignment.
The use of modern methods for setting the toe of the front wheels and the accuracy of measuring it during operation is of great practical importance, since this parameter significantly affects the durability of the tires, fuel consumption and wear of the steering joints.
Measuring the toe-in of the front wheels is a fairly precise operation, since the distance is measured within 1600 mm with an accuracy of 1 mm, i.e. the relative measurement error is approximately 0.03%. For measurements, a GARO ruler is usually used, which gives less high measurement accuracy due to the gaps between the pipe and the rod and the impossibility of installing the ruler at the same points due to the design of the tips.
The best accuracy when measuring wheel toe is obtained when measuring on optical “exacta” stands and electrical stands that use cathode ray tubes.
When checking and installing the toe of the steered wheels, it is recommended to carry out preliminary preparatory work:
correctly balance the car wheels;
adjust the wheel hub bearings and wheel brake mechanisms so that the wheels rotate freely when a torque of 5 ... 10 Nm is applied to them.
To adjust the toe-in of the wheels, it is necessary to loosen the tie rod end bolts and set the required value by rotating the pipe. Before each control measurement, the coupling bolts of the tips must be screwed in until they stop.
The front wheel hubs and brake discs are mounted on the steering knuckles.
The hubs are mounted on two tapered roller bearings. For ZIL trucks, only bearing 7608K is used. It is distinguished by an increased thickness of the small shoulder of the inner ring and a reduced roller length. The outer ring of the bearing has a barrel shape of several microns on the working surface. To protect the internal cavity of the hub and bearing from contamination, a cuff is installed in the hub bore. The outer bearing is covered by a hub cap with a gasket.
When carrying out installation and dismantling work on the hub, care must be taken not to damage the working edge of the cuff.
The hub is the supporting element for the brake drum and wheel. On the ZIL-431410 car there are two flanges on the hub. Wheel studs are attached to one of them with bolts and nuts, and a brake drum is attached to the other. On a ZIL-133GYA car, the hub has one flange, to which a brake drum is attached on studs on one side, and a wheel on the other.
It should be borne in mind that the brake drums are processed at the factory together with the hubs and can only be disassembled if absolutely necessary. Moreover, it is necessary to mark the relative position of the drum and the hub (for their subsequent assembly without disturbing the balancing and alignment).
The hub is installed on the axle as follows. Using a mandrel resting on the inner ring, press the inner bearing onto the trunnion shaft, then carefully install the hub on the trunnion until it touches the inner bearing, put the outer bearing on the trunnion shaft and, using a mandrel resting on the inner ring of the bearing, press it onto the shaft, then screw the nut-washer onto the shaft. Attention should be paid to the need to thoroughly impregnate the bearings with grease before installing them on the shaft.
When installing the hub, it is necessary to ensure free rolling of the rollers in the bearing, which is achieved by tightening the internal nut-washer 3: tighten the nut until it stops - before the hub starts braking with the bearings, turn (2--3 turns) the hub in both directions, then turn the nut - the washer in the opposite direction by V4--1/5 of a turn (until it coincides with the nearest hole of the locking ring pin). Under these conditions, the hub should rotate freely and there should be no lateral vibrations.
To finally secure the hub, install a locking ring with a washer on the axle and tighten the outer nut with a 400 mm lever wrench until it stops and lock the nut by bending the edge of the lock washer to one side of the nut. The protective cap with gasket is attached to the hub with bolts and spring washers without the use of significant force. The hubs are removed from the axle in the reverse order, with the obligatory use of mod pullers. I803 (see 9.15), ensuring uniform movement of the hub and outer bearing on the shaft, which has a fit from a clearance of 0.027 mm to a preload of 0.002 mm.
The inner bearing is mounted on the shaft with a clearance of 0.032 mm and a preload of 0.003 mm. If necessary, it is compressed using two mandrels.
It is strictly forbidden to hit with a sledgehammer when removing the hub from the axle. Impacts applied to the end of the brake drum, or to the outer flange (on ZIL-431410 vehicles) of the wheel stud fastenings, deform the flange and destroy the brake drum.
On the hub, it is necessary to inspect the outer rings of the bearings and, if they are worn, replace them with new ones. The rings are installed in the hub with an interference fit: for the internal bearing 0.010 ... 0.059 mm; for external 0.009 ... 0.059 mm. Taking into account this tension, the rings are easily removed from the hub using a punch and a hammer using special cutouts in the hub in the area of the rings.
Drive axles of three-axle ZIL vehicles
The ZIL-131 three-axle vehicle, with drive on all axles, uses a sequential drive of the rear drive axles with a through drive shaft in the first axle.
The rear axles use a double main gear located in the crankcase, cast from ductile cast iron. The final drive housing, which has a side hatch covered with a lid, is bolted to the top of a cast banjo-type rear axle housing using a horizontal flange. A bolt puller is screwed into the crankcase cover, used to press out the reaction rod pin of the rear axle suspension. The lower hole of the rear axle housing is closed by a cover welded to the crankcase. The cavity of the rear axle crankcase communicates with the atmosphere through the breather.
In the first rear axle, the drive shaft of the main gear with a small bevel gear attached to it is made through and mounted in front on a cylindrical roller bearing in the crankcase boss, and at the rear - on two tapered roller bearings, the housing of which is fixed in a flange in the crankcase and closed with a cover. At both outer ends of the shaft, the flanges of the cardan joints of the cardan transmission of the drive axles are secured to the splines with nuts. The ends of the shaft are sealed with self-clamping oil seals and dirt deflectors are welded to the hinge flanges. The second bridge has a spacer sleeve installed at the rear protruding end of the drive shaft instead of a flange and the shaft is closed with a blank cover. Otherwise, the design of both rear axles is the same.
To adjust the engagement of the bevel gears, spacers are installed under the flange of the rear shaft bearing housing, and to adjust the tightening of the bevel bearings, shims are installed between their inner rings.
The small bevel gear meshes with a large gear that is keyed onto an intermediate shaft manufactured together with the small spur gear. The shaft is installed in the inner partition of the crankcase on a cylindrical roller bearing. The outer end of the shaft rests on a double-row tapered roller bearing, the housing of which, together with the cover, is bolted to the flange in the crankcase wall. Gaskets are placed under the housing flange to adjust the engagement of the bevel gears, and to adjust the tapered roller bearing, shims are placed between its inner rings.
A small spur gear with helical teeth meshes with a large gear bolted to the differential cups mounted in the final drive housing on tapered roller bearings. The bearings are secured in the sockets with caps on studs. Adjusting nuts are screwed into the sockets on the sides to adjust the tightening of the bearings. The nuts are secured with stoppers. On the differential crosspiece, four satellites are mounted on bronze bushings, which mesh with semi-axial gears mounted on the splines of the inner ends of the drive axle shafts. Thrust washers are placed under the supporting surfaces of the satellites and semi-axial gears.
The drive axle shafts are completely unloaded and are connected by their flanges using studs and nuts with conical bushings, to the hubs of the drive wheels cast from steel. Each hub is mounted on two tapered roller bearings on a tubular axle, the flange of which is bolted together with the brake shield to the tip flange welded to the axle sleeve of the rear axle beam. The bearings are secured to the journal with an adjusting nut 44, secured with a lock washer and a lock nut. On the inside of the hub there is a self-clamping oil seal and the hub is covered by an outer felt oil seal fixed in the oil deflector.
A cast iron brake drum with a wheel disc is attached to the hub flange with studs and nuts. A hose 49 for supplying air from the centralized tire pressure control system is attached to a fitting wrapped in a trunnion. The fitting communicates using a sealing coupling 35 with a channel drilled in the axle shaft. The air supply sealing coupling consists of an annular housing to which two covers with self-clamping rubber seals are tightly attached, tightly covering the polished neck of the axle shaft on both sides of the outlet of the air channel, ensuring that when the axle shaft rotates, air flows into its channel from the hose. The coupling is closed in the recess of the trunnion by a stamped cover attached to the trunnion with bolts. The axle shaft in the flange of the tip of the semi-axial sleeve is sealed with an oil seal. The internal cavity formed by the flanges communicates with the atmosphere through the breather.
A tire valve body is wrapped into the end of the axle shaft, which is connected with a hose to the valve tube of the wheel tire chamber. The tap and hose are covered with a protective casing.
Oil is poured into the crankcase of each rear axle through a hole closed by plug 6 on the upper wall of the main gear housing. This same hole is an inspection hole and is used to check the engagement of the bevel gears. Oil is poured to the level of the control hole. The oil is drained through the lower hole on the rear axle beam cover and through the hole on the rear wall of the main gear housing. All holes are closed with plugs. During operation, the oil level in the rear axles is checked with a special dipstick included in the tool kit. The dipstick is inserted into the crankcase hole after unscrewing the rear bolt securing the main gear housing flange.
The main gear of the front drive axle has the same structure as the main gear of the rear axles, but its shafts are located in the same plane as the axle shafts, and therefore the main gear housing has a different shape and is attached to the front axle housing with a flange located in a vertical plane.
Rice. 1. Drive axles of the ZIL-131 car
The outer end of the drive shaft with a small bevel gear is installed in the crankcase on two tapered roller bearings, and the inner end on a roller bearing; cylindrical bearing. Oil is poured into the front drive axle housing through a control hole located in front of the beam cover, closed with a plug. The oil is drained through a hole located in the lower part of the front axle beam.
The outer end of each axle shaft is connected by a ball-type constant velocity joint to the wheel drive shaft mounted in a rotary axle on a bronze bushing. The hinge knuckles are made as one piece with the axle shaft and drive shaft. Thrust washers are placed under the fists. A flange is installed on the splines of the end of the drive shaft, connected on studs with nuts to the wheel hub.
The front wheel with hub, bearings, seals and air supply system to the tire has basically the same structure as the rear wheel.
The trunnion flange is bolted to the split housing. The housing is mounted on tapered roller bearings on pivot pins welded into a spherical tip, attached on studs with nuts to the end of the axle sleeve of the front axle beam. On the inside of the tip there is a double self-clamping axle shaft seal with a guide cone. Adjusting shims are placed under the axle bearing caps. For pouring oil into the housing and draining it, there are holes on the spherical tip, closed with plugs. A gland sealing device enclosing the spherical tip is attached to the outer body of the rotary axle.
The ZIL-157 and ZIL-157K vehicles have three-axle high cross-country ability, the rear axles are similar in design to the central part of the drive axle of the GAZ -63 vehicle and have a single main gear, consisting of two bevel gears, and a differential with four satellites. The main gear is installed in a crankcase that has a connector in the longitudinal vertical plane.
The tapered roller bearings of the small bevel gear shaft are adjusted by spacers or washers installed between the inner races of the bearing. The meshing of the gears is regulated by spacers installed under the flange of the bearing housing.
Each drive axle shaft is attached with a flange to the hub cover using studs and nuts. The cover, together with the wheel disc and brake drum, is attached with studs to the hub flange. In addition, the cover is attached to the hub with screws.
The hub is mounted on a journal on two tapered roller bearings, reinforced with an adjustable nut, a locked washer and a locknut. An internal rubber self-clamping oil seal and an external felt seal are installed on the inner edge of the hub.
The axle with a bushing pressed into it is attached to the flange of the semi-axial sleeve. There is a channel in the wall of the axle, to which a hose for a centralized system for regulating air pressure in tires is connected externally. A sealing coupling for air supply is fixed in the hub cover, consisting of a housing in which two self-clamping oil seals are secured with covers; the coupling is connected using a fitting to the air supply tube to the wheel tire. The tube is equipped with a stopcock; The crane body is fixed to the wheel disk.
The main gear, differential and housing of the front drive axle have the same device as the same devices of the rear axle. The end of each front axle axle shaft is connected to the wheel drive shaft using a ball-type constant velocity joint.
Drive axles of ZIL-157 and ZIL-157K vehicles
The drive shaft is mounted in a journal on a bushing and is connected to the hub cover using studs using a flange. The design of the axle, hub with bearings, and air supply channels to the tire is the same as the design of similar devices on rear drive axles.
The trunnion flange is attached to a split housing mounted on tapered roller bearings on pivot pins mounted in the spherical tip of the semi-axial sleeve. Shims are installed under the bearing caps. A gland sealing device is attached to the outside of the trunnion body.
Rice. 3. The first drive axle of the ZIL-133 car
The three-axle ZIL-133 uses rear drive axles with a through shaft, which eliminates the need to install a transfer case and simplifies the design of the cardan transmission. The main gear in both drive axles is hypoid.
In the first drive axle, the drive shaft (Fig. 3) is connected to the drive shaft of the second axle through a center differential, which, if necessary, can be locked using a clutch. The clutch is controlled using a pneumatic diaphragm working chamber located on the main gear housing and controlled by a special valve from the general pneumatic system of the vehicle. The crane handle is located in front of the driver.
Rotation from the drive shaft to the lower shaft with the small bevel gear of the hypoid gear is transmitted using gears. The upper gear is mounted freely on the shaft and is connected to it through the center differential mechanism. The lower gear is tightly fixed to the lower shaft. Transmission occurs through an intermediate gear mounted on bearings on an axis fixed in the crankcase.
The large bevel gear of the hypoid gear is mounted on the differential case, mounted on bearings in the housings of the final drive housing. From the differential, with the help of completely unloaded axle shafts, the force is transmitted to the drive wheels, the hubs of which are mounted on the tips of the axle sleeves of the rear axles on tapered roller bearings.
TO Category: - Car chassis
10 minutes to read.
Many heavy jobs cannot be done without a ZIL 131 truck. The vehicle is specially designed for transporting heavy loads over long distances. Drivers not only have to drive vehicles, but also carry out repair work while driving. It is important that the transfer case on the ZIL 131 car is always corrected. To understand how it should function correctly, what problems are possible and how they should be eliminated, you need to find out how it is designed and how it works.
Device
The ZIL 131 car has a two-stage transfer case. The front axle has an electro-pneumatic connection. In first gear the gear ratio is 2.08, and in second gear it is 1.0. The box is attached using rubber pads and four bolts, which are also attached with rubber pads to the frame cross member brackets.
In general, the transfer case on a ZIL 131 car consists of:
- Pneumatic chambers;
- Signal lamp;
- Switches;
- Rod;
- Locking device;
- Retainer housings;
- Drive shaft;
- First gear gear;
- Rear bogie drive shaft gears;
- Rear bogie drive shaft;
- Second gear clutches;
- Front axle drive shaft;
- Gear shaft;
- Crankcase covers;
- Front axle clutches;
- Second gear gears;
- Carter;
- Rod;
- Traction;
- Lever;
- Electro-pneumatic valve;
- Switch;
- Relay;
- Inlet valve;
- Exhaust valve;
- Control and filler plugs;
- Drain plugs.
The main parts include the following: crankcase with covers, input shaft with gear, clutch with bearings, front axle drive shaft along with gears and couplings. No less important is the mechanism for shifting gears and controlling the engagement of the front axle.
The box housing itself is made of cast iron, it is detachable, the back part is closed with a lid. The top hatch is also closed with a lid and a power take-off is installed on it. The top cover is equipped with a breather. The drain hole and control filler hole are located on the back cover, and there is a magnet on the drain plug. The shaft exits from the crankcase are thoroughly sealed. An oil washer is attached to the front axle shaft.
The first gear gear is installed on the key. The direct or second engagement clutch moves freely along the shaft splines. For ease of use, the gear is made immediately with the shaft. There is a worm between the shaft bearings (this is the speedometer drive); the drive gear is placed in the boss of the rear shaft bearing cover. This same cover is the support bracket on the parking brake. The intermediate gears rotate on needle bearings. The first gear clutch is located on the gear hubs. The front axle engagement clutch is also located there, where it is connected to a ring gear made directly on the shaft.
The important mechanisms on the transfer case on a ZIL 131 car include: a lever with an earring, rods, a tension spring, a pair of rods with forks, clamps, and a locking device.
Transfer case operation
The front axle is engaged by an electro-pneumatic device. It consists of:
- Electric air valve;
- Pneumatic chambers;
- Two microswitches;
- Relay;
- Switch;
- Signal lamp;
It is important to know that the transfer case in the ZIL 131 car will work normally if an electric air valve is installed on the frame cross member and a pneumatic chamber is attached to the front wall of the crankcase. The microswitch is located on the latch body and on the pneumatic chamber body, and the switch and warning light are located in the cabin, and there is a relay under the hood.
When switching on occurs, the transfer case of the ZIL 131 car gradually puts all other mechanisms into operation. The driver moves the lever forward and immediately it rotates around the attachment point on the upper link and the lower end through the link. With the help of the rod and fork, the coupling moves back and at this moment the gears are connected to each other. When the rod moves, the microswitch immediately starts working, thanks to it the relay circuit is closed, which immediately closes the circuit on the electric air valve. The armature of the electromagnet moves downwards, the inlet valve opens and the outlet valve closes.
In order for the transfer case on the ZIL 131 machine to work fully, compressed air from the pneumatic system must enter the pneumatic chamber, and it must move the coupling back through the rod and at the same time connect it to the gear ring of the shaft. The drive shaft transmits torque through the gears, which is evenly distributed between the gear and the shaft, and then passes to the axles of the rear bogie and then through the clutch it passes to the drive shaft of the front axle.
When the shutdown occurs in first gear, the transfer case on the ZIL 131 machine operates as follows:
- The electromagnet circuit opens;
- The inlet valve closes tightly;
- The exhaust valve opens;
- The front axle is automatically switched off using a return spring.
To engage second gear, the transfer case on a ZIL 131 car operates as follows:
- The lever rotates around an attachment point on the lower link;
- The coupling moves backward through the rod, rod and fork, and at the same time all mechanisms are connected to the gear inner ring of the gear;
- From the drive shaft, due to the torque, the action passes directly to the drive shaft of the rear bogie axles.
If the movement occurs on a slippery road, then you need to engage the axle in forward gear, and the electromagnet circuit should be closed forcibly. To do this you need to use the switch. The torque will be transmitted directly through the gears and clutch directly to the drive shaft on the front axle.
In all other gears, if the front axle is engaged, then the torque will be distributed in direct proportion to the loads that fall on the rear bogie axle and the front axle.
When the front axle is turned on, the microswitch will automatically close the circuit, and a warning light will light up in the driver's cabin.
The transfer case on the ZIL 131 car is lubricated with a special sprayer. Oil (in this case, its brand is Tap-15v) is poured into the crankcase. The usual rate is 3.3 liters.
Problems and solutions
Very often, a breakdown of the transfer case can be foreseen; to do this, you should only inspect the car before leaving the track and listen to the sounds occurring during operation of the mechanisms.
The following problems are possible:
- Loud noise in the transfer case. This is an indication that some parts are damaged: gears or bearings. In this case, the transfer case is disassembled and the failed parts are replaced;
- The gears turn off on their own, involuntarily. Most likely, the teeth of the carriages or the small ring gears on the wheels are worn out. Such a breakdown is possible when the gear shift forks are worn out. Damaged parts need to be replaced;
- Oil is leaking and the membrane is broken. If it is found that oil is leaking through the sealing collars, then you need to carefully inspect them. If, upon inspection, signs of wear are found on the edges, they must be replaced. If the membrane in the pneumatic chamber is broken, then it also needs to be changed;
- The control rod adjustment is broken and the pins in the rod forks are worn out. In such a situation, the thrust should be adjusted again and the fingers changed.
Maintenance
In order for the car to serve for a long time and not fail during the journey, it is necessary to carry out preventive maintenance correctly and in a timely manner.
Before work, you should always check how the transfer case is attached to the bracket and beam. The beam itself should not be ignored; it must also be attached securely and firmly. If it is found that the fastening is not at the proper level, then all parts must be tightened immediately.
It is necessary to clean the breather on the crankcase hatch cover in a timely manner. If there are blockages on it, the pressure in the transfer case will increase and subsequently there will be an oil leak through the sealing cuffs.
In order for the transfer case to be durable and reliable, it is necessary to lubricate it on time. During maintenance, the oil level is always checked and if it is not enough, then it must be added to the control plug.
The used oil is drained, the magnet on the drain plug is cleaned, and new oil is poured to the level of the control box. The same oil is used for the transfer case as for the gearbox. If the air temperature is minus 30 degrees Celsius, then TM-3-9 (or TSp-10) oil is used.
You need to pay attention to the nuts on the input and output shafts. They should be cored on the transfer case in the same way as on the gearbox.
When disassembly and assembly of the transfer case is completed, it is necessary to install a pneumatic chamber. For this purpose, shims are used. It is important that the distance is sufficient and amounts to 174 and plus or minus 0.1 mm from the end of the camera body to the holes from the locking bolts on the rods. This is necessary for subsequent installation of the plug.
Scheme
Transfer cases for ZIL 131 cars are manufactured according to the following schemes:
- With differential drive;
- With locked drive;
- With mixed drive.
Each assembly option has its own characteristics. The transfer case of the second type ensures synchronous rotation of all axles. Thanks to this scheme, torques are distributed evenly to the resistance force.
In transfer cases where the drive is made differential, the torque passes through the differential. Thanks to this scheme, the output shafts rotate at different angular speeds. This differential has another name - center differential.
In transfer cases where the drive is mixed, half of the driven shafts have the same angular velocity, and the other is connected using a differential. The “mixed” type also includes boxes with locking differentials.
From this classification we can conclude that the power flow from the main transfer case is distributed to:
- One front and one or two rear axles of cars;
- Two front axles and two rear axles;
- On the drive wheels of the left or right side of cars.
The conclusion is as follows. Transfer cases for the ZIL 131 car are:
- Interwheel;
- Intercarriage;
- Inter-sided.
Basic functions of the transfer case
The main task of this element is to transmit torque from the engine to the drive axles of the car. In addition, with the help of a transfer case, the number of gears in the transmission increases. Their purpose is also the following:
- Distributing torque between the drive axles, this allows for better vehicle cross-country ability;
- When the torque on the drive wheels increases, the “swinging” of the wheels is immediately overcome when driving on bad roads, on steep climbs and off-road terrain;
- Ensure stable vehicle movement at low speeds when the engine operates with maximum torque.
That is, the main purpose of the transfer case is to ensure good performance of the car.
Comparison with other car models
The transfer case of the ZIL 131 car has many advantages. If we compare it with the ZIL 175K car, the main difference will be in the suspension of the box. The advantages are as follows:
- On the suspension of the ZIL 131 car box, the support points of the elastic elements are spaced apart. This distributes and reduces the load;
- When removing the box on the ZIL 131, it is not necessary to disassemble all the elastic elements, you only need to unscrew the nuts of the bolts that secure the transfer case to the remaining longitudinal beams;
- If the nuts on the transfer case of a ZIL 131 car break, then replacing them will not be difficult.
In addition, if the studs on the ZIL 157K box suddenly break, they will need to be drilled out of the body; on the ZIL 131 they can be easily unscrewed.
There are many more advantages to the transfer case of the ZIL 131 car.
- On the ZIL 157K car, the suspension is supported by four studs, which are thoroughly screwed into the crankcase and passed through holes in the frame cross member. To ensure the elasticity of the suspension, rubber cushions are installed. The design is somewhat complex and therefore it will be a little difficult for the driver to make repairs on his own. While the suspension on the ZIL 131 is made on two longitudinal beams, which rest on the frame cross member. The beams are equipped with an elastic suspension, so they are reinforced with bolts that have rubber cushions made on both sides of the support.
- The transfer case on the ZIL 131 is suspended from the beams using four bolts that pass through holes on the longitudinal beams. All bolt nuts on the longitudinal beams, as well as the bolt nuts themselves, intended for fastening the transfer case, are cottered.
From the information presented above, we can conclude that the transfer case on the ZIL 131 car is more convenient, the design solution is more profitable, and it is easier to repair.
You should not drive out onto the road without inspecting the car. It is necessary to carefully check the operation of all elements. Experts advise spending a little time on preventative maintenance rather than repairing the car on the road.
The three-axle ZIL-131 is the main model of the off-road truck of the Moscow Likhachev Plant from 1966 to 1994. This is one of the most famous and recognizable cars of the Soviet automobile industry throughout the world. ZIL-131 is primarily a military vehicle, which for decades was supplied to the Soviet army and the armed forces of countries allied with the USSR.
Thanks to this prevalence not only in socialist states, but also in many, so to speak, “banana republics”, ZIL-131, unexpectedly for itself, made a long and successful film career in Hollywood.
In addition to dozens of films about James Bond and other numerous, lesser-known Cold War movie fighters, the ZIL-131 has appeared more than once in modern foreign cinema.
The Expendables team quickly restored the abandoned ZIL-131: Statham sorted out the engine, Stallone provided “wise leadership.”
In the same "Transformers", for example. Or in “The Expendables 2”: Sylvester Stallone and his “dream-team” of retro action stars famously burst into a military ZILka straight into the terrorists’ lair! At the same time, the creators of all these films, both old and new, during their filming never visited not only Russia, but even the CIS.
ZIL-131 is a front-engine all-wheel drive truck with a 6x6 wheel arrangement. Initially it was created as an all-terrain vehicle. For transporting goods and people, as well as for towing trailers - both on roads of all types and over rough terrain.
In the model range of the Likhachev Plant, the ZIL-131 replaced the no less famous, and even legendary, off-road vehicle.
In terms of cross-country ability, the ZIL-131 is not inferior even to tracked vehicles. This truck was created based on the production experience of its predecessor, the ZIL-157. The new ZIL off-road truck has been significantly improved; equipped with an innovative bridge, eight-ply tires with a special tread pattern. The ZIL-131 had a front axle that could be switched off, and both rear axles had one common driveshaft from the transfer case.
The ZIL-131 has proven itself to be an extremely durable vehicle for operation in any climatic conditions, including the Far North, tropical and equatorial latitudes, demonstrating stable and trouble-free operation at air temperatures from –45 to +55 °C.
While developing the ZIL-131, the designers of the Likhachev Plant successfully coped with the task of creating an off-road army truck that was inexpensive to produce, easy to operate and maximally unified with its “civilian counterpart.”
The first to be launched into mass production was a new mass-produced truck for the national economy -; and three years after that - the army ZIL-131. However, less than five years later, from January 1971, it ceased to be a purely military vehicle and began to be mass produced as a simplified national economic truck - without the components characteristic of army vehicles.
The serial, “classic” ZIL-131 was produced for twenty years: from 1966 to 1986, when its modernized version, the ZIL-131N, was launched into production. This version was equipped with an improved engine (improved efficiency indicators, extended service life), more modern optics and an awning made of new synthetic materials.
A few years later, they began to try to equip the ZIL-131N not with carburetor, but with diesel engines: their own ZIL-0550; motors from other manufacturers: D-245.20; YaMZ-236 and even Caterpillar.
However, the modernized 131st did not receive wide distribution, despite the fact that, in addition to the Likhachev plant, it was also produced at the Ural Automotive Plant until 2006. It’s just that production volumes were no longer the same. In the Urals, by the way, the ZIL-131N has been produced in recent years under the name Amur-521320.
The maximum level of production of 131 series trucks occurred in the 80s, when up to 48 thousand of these vehicles were produced per year. And the number of workers employed at ZIL by that time reached 120 thousand people. In total, the Likhachev plant built 998,429 vehicles of the ZIL-131 family. The absolute majority of them, of course, were during the years of the USSR. And for the entire period 1987 - 2006, both enterprises assembled 52,349 cars of an updated modification - ZIL-131N.
Main technical characteristics of the serial ZIL-131
- Length: 7.040m; Width: 2,500 m.
- Height (without cargo): in the cabin – 2,510 m; along the awning - 2,970 m.
- Wheelbase: 3350 + 1250 mm.
- Ground clearance: under the front axle – 33 cm; under the intermediate and rear axles – 35.5 cm.
- The track size of the front and rear wheels is the same: 1.820 m.
- The smallest turning radius on a dry asphalt road with the front axle turned off is: in the middle of the track of the outer front wheel - 10.2 m; along the fender of the outer front wheel - 10.8 m.
- Tire size – 12.00-20″.
- Dimensions of the cargo platform (length/width/height, in millimeters): 3600 / 2322 / 346+569.
- Loading height: 1430 mm.
- Highway load capacity: 5 tons; on ground cover: 3.5 tons.
- Unloaded vehicle weight: 5.275 tons.
- Curb weight: 6.135 tons - without winch; 6,375 tons - with winch.
- Gross vehicle weight: without winch – 10.185 tons; with winch - 10.425 tons.
The distribution of the load transmitted to the road from the mass of the equipped vehicle through the tires is: 27.5/30.45 kN (2750/3045 kgf) – front axle; 33.85/33.30 kN (3385/3330 kgf) – rear bogie.
The distribution of the load transmitted to the road from the total weight of the vehicle through the tires is equal to: 30.60/33.55 kN (3060/3355 kgf) – front axle; 71.25/70.70 kN (7125/7070 kgf) – rear bogie.
The overhang angle parameters are as follows: front without a winch - 45 degrees, with a winch - 36 degrees; rear - 40 degrees.
Engines ZIL-131
- The main, “native” engine of the serial ZIL-131 is a 4-stroke eight-cylinder V-shaped 90° carburetor engine with a volume of 6 liters. Its rated power (with rev limiter) is 150 horsepower. The power unit belongs to the overhead valve type of engine, liquid cooled. The cylinder diameter is 100 mm; piston stroke – 95 mm. Compression ratio – 6.5. Torque – 41 kgf*m (410 Nm). Specific fuel consumption is at least 35-38 liters per 100 kilometers. Its considerable power needs are provided by two fuel tanks of 170 liters each.
- 150-horsepower engine modernized in 1986 ZIL-5081 V8 It differs from the previous engine in cylinder heads with screw inlet ports and a compression ratio increased to 7.1. This engine was also slightly more economical than its predecessor.
- Diesels with which, already in its recent history, the ZIL-131 was equipped: D-245.20– in-line four-cylinder diesel engine with a working volume of 4.75 liters. The rated power of this engine is 81 horsepower, the maximum torque reaches 29.6 kgm. Diesel fuel consumption is 18 liters per 100 km; YaMZ-236– six-cylinder V-shaped diesel engine with a volume of 11.15 liters. The rated power of this engine is 180 hp; own four-stroke diesel plant named after Likhachev ZIL-0550(6.28 l, 132 hp). However, the ZIL-131 diesel truck is still a rarity.
Frame and suspension of the ZIL-131 truck
The frame of the ZIL "SUV" is stamped, riveted, with channel-section spars, which are connected by stamped cross members. At the rear there is a hook with a rubber shock absorber; In front of the frame there are two rigid towing hooks.
Front suspension - on longitudinal springs; the front ends of the springs are fixed to the frame using lugs and pins, and the rear ends of the springs are “slippery”. The rear suspension is balanced, on two longitudinal springs. The shock absorbers (on the front suspension) are hydraulic, telescopic, double-acting.
The truck is equipped with disc wheels with 8-stud fastening. The front dependent suspension of the truck is installed on two semi-elliptic springs, equipped with shock absorbers and rear sliding ends. The rear suspension (balancer) is mounted on two semi-elliptic springs with sliding ends and 6 reaction bars.
Steering and brake control; transmission ZIL-131
The truck is equipped with a hydraulic power steering drive located in a common housing with the steering mechanism. The steering mechanism - the working pair - is a screw with a nut on circulating balls, and a rack that engages with a gear sector.
The power steering pump is a vane type, double acting, driven by a belt from the crankshaft pulley. The steering gear ratio is 20. The longitudinal and transverse steering rods are with heads on ball pins, with self-clamping nuts.
The brake mechanisms of the service brake system are drum type with two internal pads, unclenched by a fist, installed on all wheels. The brake drum diameter is 420 mm; pad width – 100 mm.
The total area of the brake linings is 4800 cm2. When the service brake system is turned on, the drive of the brake mechanisms is pneumatic, without separation along the axes. There are six brake chambers, type 16.
The brake mechanism of the parking brake system is a drum type with two internal shoes, unclenched by a fist, installed on the transmission shaft. The braking distance on a dry, asphalt, flat highway from a speed of 60 km/h is about 25 meters.
ZIL-131 is equipped with a five-speed manual gearbox, with two inertial synchronizers for engaging second – third, fourth – fifth gears. Transfer case – mechanical, 2-speed (2.08:1 and 1:1); The main gear is double, with a pair of bevel (gear ratio 1.583) and a pair of cylindrical (gear ratio 4.25) gears. Cardan transmission is open type.
The clutch is single-plate, dry, with a spring-loaded torsional vibration damper (damper) on the driven disc. Friction linings are made of asbestos composition. The number of pairs of friction surfaces is 2.
Some modifications of the vehicle are equipped with a drum-type winch, complemented by a worm gearbox with a maximum traction force of 5000 kgf. The length of the winch cable is 65 meters.
Axles of the ZIL-131 truck
The beams of the driving axles are steel, welded from two stamped halves with welded flanges and a cover. The four cardan shafts are equipped with joints on needle bearings. Main gear – two-stage rear axle drive (sequential, continuous)
The front axle drive is switched on automatically (by an electro-pneumatic valve) when the first (lower) gear is engaged in the transfer case; forced - when the second (direct) gear is engaged with a switch installed on the front panel of the cab.
When the front axle is turned on, a warning lamp on the instrument panel in the cockpit lights up. When starting, the downshift lever, which is part of the transfer case, forcibly turned on the pneumatic drive of the front axle.
ZIL-131 is equipped with a contactless ignition system equipped with an electronic switch and an automobile generator with increased power. Additionally, there is an emergency generator, which allows, in the event of failure of the electronic switch, to move under its own power for about 30 hours, without a significant loss in dynamics.
Cabin ZIL-131
The cabin is all-metal, three-seater, heat-insulated. The cabin is heated with water, from the engine cooling system, with a centrifugal fan. The heater duct damper control handle is located on the cab panel. Cabin ventilation is carried out through roll-down windows, rotary door vents and a duct in the right wing mudguard.
The seats in the cabin are separate. In this case, the driver's seat is adjustable, the passenger seat is double. The seat cushions are made of sponge rubber.
Cargo platform and body of the basic ZIL-131
The body of the ZIL-131 is a wooden platform with a metal frame and metal transverse base bars. The front and side sides of the body are solid, the rear side is folding.
The truck platform is adapted for transporting people: there are folding benches for 16 seats on the side rails, and there is also an additional middle removable bench for 8 seats. The body is covered with an awning on installed arches.
Review of ZIL-131 modifications
- ZIL-131– the basic version, mass production of which lasted from 1966 to 1986.
- ZIL-131A– special version with unshielded electrical equipment. It differed from the basic modification in the absence of special military equipment, an average bench in the back and a searchlight.
- ZIL-131V– a truck tractor developed on the basis of the ZIL-131. In this modification, the car’s frame was shortened; It was equipped with a fifth wheel coupling and two spare tires. The ZIL-131V tractor could transport a semi-trailer weighing 12 tons (on paved highways) or 10 tons (on dirt roads). Produced from 1968 to 1986.
- ZIL-131D- dump truck. By the way, the same name was given to a rare and “exotic” version of the 131st ZIL in 1992, equipped with an imported Caterpillar diesel engine, which was produced in very modest quantities until 1994.
- ZIL-131S And ZIL-131AS– trucks for the regions of the Far North, Siberia and the Far East. These modifications were equipped with a cabin with an autonomous heater, frost-resistant rubber products, additional thermal insulation, standard fog lights, battery insulation and double glass. Designed for use at temperatures up to -60 degrees. We gathered in Transbaikalia, at the Chita car assembly plant.
- ZIL-131X– version adapted for desert and tropical climates.
- ZIL-131N- a version of the base model modernized in 1986. Innovations: improved ZIL-5081 V8 engine, with a resource increased to 250 thousand km, an awning made of more modern synthetic materials and improved optics.
- ZIL-131NA– version ZIL-131N, equipped with unshielded electrical equipment.
- ZIL-131NV– a truck tractor with an improved platform.
- ZIL-131N1– modification with a 105-horsepower diesel engine D-245.20;
- ZIL-131N2– version with a 132-horsepower ZIL-0550 diesel engine;
- ZIL-131NS, ZIL-131NAS And ZIL-131NVS– modified versions of the northern version;
- ZIL-131-137B– road train.
Special vehicles based on ZIL-131
A significant volume of production was occupied by a universal chassis designed for mounting various superstructures and special equipment. In addition to the well-known fire trucks, the following were also produced on the ZIL-131 chassis:
- Fuel tankers: ATZ-3.4-131, ATZ-4.4-131, ATZ-4-131;
- Oil tankers: MZ-131;
- Universal tank trucks: ATs-4.0-131, ATs-4.3-131.
- Airfield mobile units (tractors): APA-50M; APA-35-2V. It is interesting that these ZIL-131s serving in aviation had a total weight in excess of the officially permitted one: 10,950 and 11,370 tons, respectively.
For army versions of workshops, laboratories, mobile radio stations, command and staff vehicles, standard KUNG K-131 and KM-131 van bodies were developed. These KUNGs were equipped with a special filtration unit FVUA-100N-12. It takes air from the surrounding atmosphere and supplies it to the van, simultaneously disinfecting it.
