Screw all-terrain vehicle: the principle of operation, brand. Amphibian-terrain vehicle
As for movement on especially heavyoff-road, represented by fragile surfaces, conventional wheels are not suitable, vehicles designed for such conditions establish mechanisms that reduce pressure on the ground. Usually, they are represented by low-pressure wheels or caterpillars. Very rarely use augers. Next, we consider the construction, the principle of functioning of machines equipped with them and some of their models.
Screw-rotor all-terrain vehicle, or auger,It is a vehicle that moves by using a screw-rotor engine. In view of the wide variety of surface types for whichsuch machinescan move,have some other names.
The propeller-driven propulsor is usually represented by twolocated coaxially with the direction of movement of Archimedes screws, consisting of high-strength material. This mechanism is a tilted pipe with a screw inside. The screw is created in the form of an inclined plane, screwed onto the cylinder.
Created, presumably, Archimedes in 250 g. BC. e. or even earlier, in Greece, originally these devices were intended to lift water to irrigation canals. Much later, in the second half in., Vehicles appeared, in which instead of wheels or tracks, such mechanisms were installed. These modern analogues of Archimedean screws are called augers.
Appliances used on machines, externallyare horizontal cylinders, ending in cones on both sides. Outdoors, they are covered with grooves of a spiral shape. Augers are usually produced from non-ferrous metals. They are either hollow, or filled with some light polymer, for example, foam. This provides a low specific pressure on the surface, so that vehicles equipped with them are able to move on such soft surfaces as snow and dirt, and even on water.
Principle of functioning
The essence of the work of the considered engines isThe fact that with the rotation of the augers, the lugs on the thread are screwed into the surface. The rotation in such a system is organized on the same principle as for tracked vehicles: the internal screw is slowed down.
The mechanism under consideration provides highpassability when driving on ice, snow, debris, and also allows for movement on water. At the same time such vehicles are not suitable for movement on hard surfaces like asphalt.However, in off-road conditions, this type of running gear is also not an ideal option, as it significantly damages the surface, including vegetation.
This screw-type all-terrain vehicle was created in 1972. The developer was ZIL. And even before that, he conducted experimental work on such vehicles. So, from 1968 to 1969 years. An experienced all-terrain vehicle SHN-1 was developed. For the new machine, these developments were used.
It was equipped with two ZIL-375 engines with pre-start heaters. This is an 8-cylinder shaped motor with a volume of 6.9 liters, developing 180 liters. with., which installed on ShN-1. Each of them has its own hydromechanical automatic transmission. Torque through the transfer box is transferred to the main gearbox, which has two outputs. Through them, it enters the on-board transmissions, each of which drives the corresponding auger.
Throttle control at ZIL-4904was initially carried out by the accelerator pedal, then this function was transferred to the handle. For turning, the system includes levers, dry multi-disc clutches and final drive brake. Brakes of tape type. The augers were made of light alloy. The diameter of each is 1.5 m, and the length is 5.99 m. This screw-type all-terrain vehicle was equipped with a pumping system, thus simplifying the movement through the swamps and water. And on hard roads it was transported on a specialized trailer-tow truck.
The cabin for weight loss was made fromfiberglass, but the waterproof case is steel. In the cockpit there were 3 people, 4 more in the cabin. ZIL-4904 existed in passenger and cargo variants. And one was made from the other. Initially, the cabin was installed glazed passenger compartment of fiberglass for 8 seats. Then it was removed, and the loosened cargo platform was covered with a tent. So it turned out a cargo auger all-terrain vehicle with a carrying capacity of 2-2.5 tons. The dimensions of the hull were 8.575 m in length, 3.6 m in width, 3.44 m in height. Due to this ZIL-4904 became the largest vehicle of this type. Its mass is 7,065 tons.
However, he had very modest dynamiccharacteristics. And the speed of movement varied depending on the coverage. Most quickly, this auger cross-country vehicle traveled in the snow (10.5 km / h) and along the water (10.1 km / h). On the swamp, he could accelerate to 7.3 km / h and most slowly moved along the plains (4.45 km / h). At the same time, fuel consumption was very high. When moving along the swamp, it reached 65-73 l / 100 km, and along the water it reached 75-85 l / 100 km.
This amphibian-terrain vehicle was developed in 1973. with the use of constructive solutions of the machine discussed above. So, for him used similar layouts of controls, transmission scheme, screw material.
the difference from the previous model, which never found application, this machine was originally developed for the search and rescue complex of astronauts,where euse to this day. Since their landing can occur in any terrain conditions,The best variant of such a vehicle was considered to be a screw-rotor snow-aerial vehicle.
That car is much more compact than its predecessor,since these tasks do not require a high load capacity, but need a high speed. Its length is 3.8 m, its width is 2.3 m,weight - 1280 kgIt was provided for 2 sitting and 2 lying places. In view of such compact dimensions, two engines were used to reduce the mass, and also simplify the designMeMZ-967Acapacity of 37 liters. fromEach of them is docked with a single-disk clutch, planetary gear,stepped gearboxwith a reverse mechanism, establishedat an angle of 45to the engine. The maximum speed is 15 km / h.
In 1979 have developed an upgraded version, ZIL-29061. This amphibious cross-country vehicle is distinguished by its large body dimensions. The length was increased to 4.86 m, the width to 2.39 m. The engines from Zaporozhets were replaced by VAZ engines with a capacity of 77 liters. from. complete with 4-speed manual transmission. The mass is 1,855 tons. The maximum speed has increased by 10 km / h.
- DAF Amphirol.Created in Holland in 1966, that is, before the ones considered aboveSovietmachines. In doing so, hemuch faster than them (overland could accelerate to 35 km / h) and also movingsuckedon water. However, this amphibian-scraper was not a factory product, but a private development equipped with an engineDAF.
- Fordson Snow Devil.The only American serial car of this kind of companyArmstead Snow Motor.produced in the 1920's. on the basis of tractorsFordson.
- SHN-67 "Shnek". This is the first screw-type all-terrain vehicle developed by ZIL, created in 1967. Later, the upgraded version of ShN-68 was developed. Based on these machines, the ZIL-4904 considered above was created.
- GPI-16. This model differs in design from the others considered, since it is a monotonous. That is, in the running gear the augers are aligned with the skids. This screw auger was developed by the laboratory of snowmobile machines of the Gorky Polytechnic Institute. There were quite a few of his models, but each in one copy, and they were not widely spread.
- Snowbird 6.A modern British model, created in 2001. It is a sculler-transformer,which wouldThe boat was specially designed for the expeditionIce Challenge.
- MudMaster.Submitted in 2002 by the companyResidue Solutions.It is designed to service irrigation stations of silt fields, as well as for work on marshes, coastlines, mangrove forests, etc. Due to this model by nowResidue Solutionsbecame the leader in the production of such machines.
Functional qualities are determined by the targetpurpose: screw propellers are installed on ATVs and amphibians for particularly severe conditions. However, due to the destructive impact exerted on the surface, and also due to the highly specialized nature of these mechanisms in the field of okhodokodostroeniya have not found extensive application.