Two-stage rotary snow blowers
The separate principle of snow removal assumes that the drive of the feeder and the throwing apparatus is carried out through an individual kinematic chain. Due to this, for each of the mechanisms, it is possible to select the operating mode, shape, location and number of structural elements, taking into account the optimal working conditions.
There are two types of two-stage snow blowers: auger and rotary milling. The main difference between them lies in the different design and layout of the feeder, which, in turn, determines the size of the auger used to develop the snow mass.
Plow-rotary snow blowers
This type of equipment, which has a fairly simple design, has found application, first of all, for cleaning railway tracks from snow drifts. In public utilities, plow-rotary snow blowers are rarely used and mainly for cleaning streets and sidewalks with the formation of snow swaths. When removing dense snow, "plows" are not economically viable.
Plow-rotary snow blowers are installed on tractors, mini-loaders, special chassis. The working body is a plow with built-in rotors (which can be one or two). The rotors have oppositely directed helical blades (knives). To loosen the packed snow, use the working edges of the blades with teeth.
Snowblower device
The rotary snow blower is simple enough. The unit consists of a "snail" - a round body. A snow throwing sleeve is placed on top. The guide vanes are welded in front of the body. Inside the snow blower, the rotor rotates at high speeds.
It consists of an impeller pinned to a shaft with bearings. The mechanism drives the engine. When the rotor of the snow blower starts to rotate, the impeller blades begin to pick up the snow for themselves, grind it inside the snail, and then throw it out a few meters to the side through the sleeve.
Homemade rotary snow thrower can be made in two varieties:
- With a stationary motor. In this case, the snow blower functions as a full-fledged machine.
- As a carport for other vehicles. They do not put a motor on such rotary homemade products. The snow blower is hung on a mini-tractor or walk-behind tractor. The drive is carried out through a chain or belt drive.
Rotary snow blowers also differ in the type of engine:
In electric models, the rotor runs almost silently. They do not require consumables and are easier to maintain. For the inconvenience, you can count the cable constantly dragging behind the snow blower. Instead, preference is given to a battery model, however, the operating time of such a unit is very limited. All electric snow blowers are unfortunately underpowered. They are almost always used in private yards and dachas to clean the paths from loose fresh snow that has fallen out.
Gasoline rotary models are an order of magnitude more powerful than electric snow blowers. Their only drawback is more complicated engine maintenance, the presence of exhaust gases and regular refueling of fuels and lubricants. However, the petrol snow blower is not tied to an electrical connection. The power of the engine makes it possible to produce a rotor mechanism of large dimensions. Such a rotary device has an increased working width, capable of handling not only thick snow cover, but also snowdrifts.
By the type of movement, rotary snow blowers are divided into:
Non-self-propelled. Such units move by pushing them by the operator. Electric snow blowers are usually included in this category, however, there are also low-power gasoline options among them. The equipment needs to be nudged slightly.Due to the capture of the snow cover by the impeller, the snow blower will spontaneously move forward.
Self-propelled mechanisms most often operate from a gasoline engine. The snow blower drives independently on wheels. The operator only sets the course for him.
The rotary snow plow can also be classified as a self-propelled vehicle, although it does not even have a stationary drive. But you don't have to push it with your hands. The hitch will move with a mini-tractor or walk-behind tractor.
The principle of operation of the auger
The screw-rotor mechanism consists of two parts, which can be operated separately:
- screw;
- rotary.
The basis of the auger snow blower is a multidirectional auger that runs from both edges to the center of the part.
As the auger rotates, its blades move the snow towards the center, and the blades located in the center throw it out at high speed.
After that, the snow passes through the chute, which gives it the right direction and flies off to the side of the road.
Instead of one huge auger, usually 2 small augers are installed for:
- increased productivity;
- reducing the weight of the unit.
However, in terms of productivity, even twin-shaft auger devices are much inferior to auger-rotor ones.
The basis of the rotary (milling) mechanism is a small rotating shaft equipped with various blades.
This shaft works on the principle of a centrifuge - it accelerates a small mass of snow to a tremendous speed. When the snow mass reaches the hole in the rotor casing, it flies out under the action of centrifugal force.
The correct direction of the snow mass is given by the swivel chute.
In the screw-rotor mechanism, the auger:
- crushes snow;
- feeds it to the fast rotating rotor.
The latter does not cope well with coarse unmilled snow, but it throws out the ground snow mass very well.
Therefore, the efficiency of auger snow blowers is much higher than that of auger or milling machines.
Both mechanisms can be linked or not mechanically linked.
Indeed, in the overwhelming majority of cases, both the auger and the rotor are driven by a hydraulic motor.
And the hydraulic motor is connected to the hydraulic system of the tractor or truck.
There are also models that operate from a power take-off shaft (PTO) connected to:
- vehicle motor;
- gearbox;
- transfer case.
Rotary snow blowers
Rotary snow blowers are equipped with an active working body, usually mounted on a self-propelled chassis. These snow blowers are designed to clean roads and airfields from large and relatively dense snow masses with an irregular nature of snow removal, removing snow banks, clearing mountain road sections from fallen, swept and avalanche snow, as well as removing snow from city streets and squares and throwing it to the side. or loading into transport.
By the type of the working body, rotary snow blowers are divided into plow-rotary, auger-rotary, milling-rotary and with a combination of the working body.
The working body of the plow-rotary snowplow consists of a plow with built-in one or two blade rotors. The mass of snow cut by the plows moves along the inner skin of its body, which is usually made in the form of a conical surface, to the rotor (s), which throws the snow aside.
Plow-rotary snow blowers are used mainly at work in dry, loose snow of low density. The working body of the auger-rotary snow blower consists of an auger feeder (with one, two or three augers) and a vane rotor, mounted in a common housing. The feeder augers cut the snow out of the solid and direct it to the rotor. The snow mass that entered the rotor is thrown aside by it. Rotary auger snow blowers work well on snow of medium density and hardness and poorly on very dense, hard and frozen snow.The working body of the rotary-milling snowplow consists of a milling feeder and one or two blade rotors mounted in a common housing. The milling feeder is made in the form of a drumless cutter of a large diameter with cutting elements, which are screw bands, fixed by means of racks and braces on the axes of the cutters. Such a feeder has a large throughput and good cutting properties, so it can be successfully used in the development of dense and hard snow. Like an auger, a milling feeder cuts snow out of the solid and feeds it to the rotor, which throws it to the side. The combined working body of a rotary snowplow is usually made in the form of hollow drums, inside of which there are drive elements of the working body with right and left cutting belts wound on their outer surface along a helical line, forming pockets at the point of closing for receiving the snow mass. When the drum rotates, the belts take snow from the snow mass into the cavity between the outer edge of the belt and the surface of the drum, which, moving along the belt, enters the pocket from the right and left turns. These snow blowers are more compact than auger and rotary milling machines, and are capable of producing snow of any density and strength, but they are very energy-intensive, low-productive and cannot provide a long range of snow throwing.
Rotary snow blowers are divided into:
- by type of chassis for pneumatic and tracked;
- by the type of base machine - for automobile, tractor, mounted on a tractor, loader and own chassis;
- in terms of productivity - for light (up to 200 t / h), medium (up to 1000 t / h) and heavy (over 1000 t / h). Medium and heavy vehicles are subdivided according to the range of snow throwing into road (up to 18 m) and airfield (over 18 m).
By the number of installed engines, single-engine snow blowers with one common engine and twin-engine (in rare cases multi-engine) with separate engines for the drive and working bodies are distinguished.
The initial parameters for the calculation are the productivity Q in t / h, the distance of throwing the snow mass, the height of the developed snow layer H in meters and the physical and mechanical properties of the snow.
The need for drawings of rotary snow blowers
To correctly assemble snow removal equipment, you need blueprints. On the network, there are many options for schemes of devices of the simplest rotary snow removal equipment.
For each type of unit, not every scheme is suitable. For example, for owners of a mini-tractor - and this is a very powerful technique - it is irrational to cling to a rotary hitch. Most often, a combined mechanism is produced for this type of equipment. The hitch consists of a rotor and auger. Such a snow blower is capable of handling large snow drifts.
The combined type snowplow will cope with packed and wet snow, as well as icy crust. A toothed edge is made on the circular blades of the auger to obtain greater productivity. It crumbles the ice according to the principle of a saw into small particles.
Step-by-step assembly of the unit
The snow thrower frame is the base. All working parts are attached to it. In general terms, the frame of a snow blower is a rectangular unit welded from a profile and corners. It is impossible to give clear directions for its manufacture, since everything will depend on the spare parts used.
Suppose you can take the engine from a cultivator, chainsaw, or put an electric motor. For each individual unit, you will need to individually invent a mount.
Snow blower frame installation
If the rotary snow blower is used as a hinge for the walk-behind tractor, then the motor can be omitted.Consequently, the frame must be made shorter so that there is enough space to secure only the rotor with the volute.
When designing a mounted snowplow, a bracket must be welded onto its frame to ensure coupling with the walk-behind tractor.
If the rotor mechanism is self-propelled, then a wheelset mounting block must be provided on the frame. A non-self-propelled snowplow is best placed on skis. To do this, you need to weld on the bottom of the mounting frame, and fix the wooden runners on them.
Hand-made production and assembly of the rotor
The most difficult element of a snow blower is undoubtedly the rotor. The main requirement is imposed on the impeller. It can contain from 2 to 5 blades. However, that's not the point. Their number depends on subjective tastes. The most important thing is to make sure that each of the blades has the same weight. Otherwise, an imbalance will occur and the device will wobble.
You won't be able to work with such a machine. At the moment of rotation of the unbalanced impeller, the unit will bounce in place from irresistible vibration. Therefore, the one who will not spare money to order parts for a snow plow rotor in a special workshop with lathes will do the right thing.
Making a "snail" with your own hands
The configuration of the rotary snow blower case is somewhat similar to a snail, which is why it was given such a name. For its production, a piece of pipe of the required diameter with a length of 15-20 cm will be required.One side of it is tightly welded with a metal sheet. This will give the back wall of the snail. It is to it that the rotor bearing hub will need to be attached. In front of the sides of the ring, 2 guide vanes are welded.
A hole is cut at the top of the ring and a sleeve for the sleeve is welded into it. The first part of the snail is covered by one third so that the snow is discharged through the sleeve, and does not fly in front of the rotor. It is preferable to make the plug on hairpins, removable. Such a system will make it possible to quickly get to the impeller.
Now we fix the rotor inside the snail. To do this, in the middle of the back wall of the volute, a hole is drilled for the shaft. They put the rotor in its place, while tightly pressing the bearing hub to the casing. On the lugs of the flange, notice the location of the holes for the fasteners. The rotor is removed from the casing, holes are drilled, then the mechanism is installed in place and the hub is pulled with the bolts from the rear wall of the snail.
So, inside the casing there is a protruding rotor shaft. An impeller is mounted on it and carefully tightened with nuts. On the outside there is a protruding second shaft end and a hub with bearings. A belt pulley is placed on the shaft. If you prefer a chain drive to a belt drive, instead of a pulley, an asterisk from a moped is reinforced. The rotor is ready.
The unconditional advantage of a rotary homemade product is the reality of producing a snowplow with the required working width, as well as significant cost savings.
Price
We have compiled a small table in which we included some models of auger, milling and milling-rotary snow blowers. The information in the table will help you understand the approximate cost of a snow blower.
If you want to purchase a rotary snow blower, but you need to clear a small area, we recommend purchasing a manual (household) version of such a unit. You can find out about them in this article.
There is also an option to purchase a mounted auger snow blower for a mini tractor or MTZ. Such equipment is less efficient, but cheaper. It is also suitable for cleaning small areas.
Single stage rotary snow blowers
Advantages:
- Due to the combination of two operations, such equipment is more compact and, as a result, more maneuverable.
- By reducing the load on the bridge closest to the working body, the snow blower has a higher transport speed
Disadvantages:
Decrease in machine productivity due to inefficient distribution of power in the working body.
In single-stage snow blowers, two operations are combined - the development of the snow mass and its throwing away from the direction of travel. In this case, the snow cutting speed is limited to 9-10 m / s, and the transportation process requires peripheral speeds 2-3 times higher (an increase in the distance over which snow is thrown is achieved by increasing the rotational speed of the actuator). This leads to power losses and low popularity of single-stage snow blowers. The combination of cycles is used in two types of snowblowers: plow-rotary and milling machines.
Rotary auger snow blowers
Read How to get started in cold weather?
Rotary auger snow blowers have gained the greatest popularity in Russia. They are installed on cars, tractors and special chassis. The purpose of the auger rotor machines is to throw away snow shafts formed by other snow blowers and load snow into vehicles using a loading chute. They are used both for carrying out snow-clearing works on highways and at airfields.
In the series of auger snow blowers, in turn, there are models made according to a single-engine scheme (torque transmission to attachments and power take-off to the travel mechanism are carried out from one engine) and twin-engine (the working body is driven from an additional diesel engine mounted on the base chassis frame , and movement - from the standard engine).
Experts highlight a number of disadvantages of the twin-engine drive circuit for auger snow blowers. Let's name the main ones:
- Irrational use of the base chassis engine. In the operating mode, the diesel engine is loaded only by 10%, the rotational speed for a significant time is less than the nominal. These factors provoke coking of the combustion chamber, valves and nozzles, which is the cause of premature engine failure and excessive fuel consumption.
- Cross direction of power flows. The travel motor drives the rear bogie of the car chassis, and from the engine located behind the cab, the torque is transmitted to the working body, which is hinged in front of it.
- Overloading the front axle in transport mode. The negative consequence of this can be the destruction of the bridge, which is prevented by limiting the speed of the auger snow blowers to 40 km / h.