RU2301295C1 - Small-size snow-plough - Google Patents

Abstract

FIELD: snow-ploughs of rotor type.

SUBSTANCE: snow-plough comprises chassis carrying drive and case for drive closing, cylindrical working chamber with rotor and outlet orifice, guiding sheets and drive control means. Rotor is connected to drive shaft and includes disc-shaped base transversal to axis of drive shaft and blade rotation. The blades are bent of flat sheet material. Line of each blade intersection with any plane transversal to rotor rotation axis substantially mates shape of logarithmic spiral section defined by rotor convex in rotor rotation direction. The blades are inclined with respect to disc-shaped base so that angle between the blade and disc-shaped base in less than 90° in rotor rotation direction. The blades are fastened to disc-shaped direction along joint line shaped as logarithmic spiral section defined by rotor convex in rotor rotation direction.

EFFECT: increased snow-shifting capacity along with decreased snow removal cost and reduced labor inputs for snow-plough production.

4 cl, 7 dwg

Description

The invention relates to rotary snow removal units and can be used to clear sidewalks, pedestrian walkways and roads from loose snow.

A small-sized snow removal unit is known, consisting of a chassis on which an engine, a casing closing the engine, guide shields, a working chamber with a rotor mounted on an engine shaft and consisting of a base in the form of a circle and blades curved from a flat sheet material, the axis of rotation of the rotor are mounted parallel to the direction of movement of the unit. The contact line of the blades and the base, as well as the cutting edges of the blades are segments of straight lines [1].

A disadvantage of the known unit is the low efficiency of trapping and moving snow due to suboptimal shapes of the cutting edge of the blades and the surface of the blades.

Known snow removal unit, consisting of a chassis on which an engine, a casing covering the engine, guide shields, a cylindrical working chamber with a rotor mounted on the motor shaft and consisting of a base in the form of a circle and blades mounted with an inclination with respect to the base of the rotor are mounted so so that the angle between the blade and the base in the direction of rotation of the rotor is less than 90 °, the cutting part of the inner edge of the blade has a spiral shape. The contact line of the blades and the base can be either a straight line or a curved line having a concave shape in the direction of rotation of the rotor [2], [3].

The disadvantages of the known working body is the insufficient strength of the blades due to their considerable length in the direction of rotation during cantilever fastening and the low efficiency of moving snow outside the unit due to the non-optimal surface shape of those sections of the blades that are adjacent to the base and perform this movement.

The aim of the invention is to provide high performance snow moving at low cost and the complexity of manufacturing the unit.

This goal is achieved by the fact that in a small-sized snow removal unit, consisting of a chassis on which an engine is installed having its controls, a casing covering the engine, a cylindrical working chamber with an outlet and guide shields, the rotor mounted inside the working chamber on the motor shaft and consists of a disk base perpendicular to the axis of rotation of the motor shaft, and vanes uniformly attached to it, the vanes are curved from a flat sheet material and fixed to the disk base along the line connecting the blades with the disk base, which has a section of a logarithmic spiral convex in the direction of rotation of the rotor, the blades are inclined to the disk base so that the angle between the blade and the disk base in the direction of rotation of the rotor is less than 90 °, the cutting edge of each blade has a section shape a logarithmic spiral convex in the direction of rotation of the rotor.

Two adjacent blades can be made in the form of a single part, combining two adjacent blades and an insert section between them.

The small-sized snow removal unit can be equipped with handles for moving the unit during operation and for carrying it.

Engine controls can be mounted on the handle to move the unit during operation.

The blades may have a small length in the direction of the axis of rotation of the rotor.

Figure 1 shows a front view of a compact snow removal unit.

Figure 2 shows a top view of a compact snow removal unit.

Figure 3 shows a side view of a compact snow removal unit.

Figure 4 shows a front view of the rotor.

Figure 5 illustrates the surface shape of the blade and shows the forces acting on a snow particle sliding over the surface of the blade.

Figure 6 shows the construction of the surface of the blades, unfolding on a plane.

7 shows a projection on the base of the rotor of two blades made of one flat sheet.

The small-sized snow removal unit consists of a chassis 9, on which an engine 5, a casing 10, which covers the engine 5, a cylindrical working chamber 1 with a rotor 2, an inlet 15 and an outlet 13, guide shields are mounted 3. The rotor is mounted on the motor shaft 4. Handles 6 used to move the unit during operation. Handle 8 is used to carry the unit. The controls 7 are used to start and stop the engine 5. As the engine 5 can be used either an internal combustion engine or an electric motor that is powered from the mains by cable. The rotor 2 consists of a disk base 12, perpendicular to the axis of rotation of the shaft and the blades 11. The blades 11 are bent from a flat sheet material. The blades 11 are installed with an inclination with respect to the disk base 12 so that the angle between the blade 11 and the disk base 12 in the direction of rotation of the rotor 2 is less than 90 °. 4, the cutting edge of the blade 11 is shown in the form of a curve ABC. The pairing line of the blade 11 and the disk base 12 is shown as a curve A ₁ B ₁ C ₁ . The curve abc is obtained by the intersection of the blade and the plane perpendicular to the axis of rotation of the rotor. In Figs. 4 and 5, point O is the intersection of the axis of rotation of the rotor and the disk base of the rotor 12. In Fig. 5, a part of the trajectory of the point G belonging to the surface of the blade 11 is shown in the form of an arc efg of a circle with a radius R. The angle β of the slope of the curve abc at G there is an angle between the tangent de to the curve abc at G and the tangent pq to the arc efg at G. If the curve abc is a section of a logarithmic spiral, then the slope is the same for any of its points. In Fig. 5, the force F _d is the component of the pressure force of the surface of the blade on the snow particle at point G in the plane perpendicular to the axis of rotation of the rotor 2, is perpendicular to the tangent de to the curve abc at point G. The force F _dr is the component of the force F _d in the radial direction. The angle between the forces F _d and F _dr is equal to the angle of inclination of the curve abc at point G, i.e. equal to β.

Figure 6 shows the construction of the surface of the blades, unfolding on a plane. Oz is the axis of rotation of rotor 2. xOy is the plane perpendicular to the axis Oz of rotation of rotor 2. O is the intersection of the axis Oz of rotation of rotor 2 with the xOy plane. A system of polar coordinates was introduced in the xOy plane, with the pole of this coordinate system coinciding with the point O, and the polar axis coinciding with the positive half-axis of the axis Ox directed to the left. As a positive direction of rotation of the radius vector, which sets the position of the point in the specified polar coordinate system, the direction of rotation is clockwise.

The cutting edge ABC of the blade 11 lies in the xOy plane. The cutting edge ABC of the blade 11 has the shape of a section of a logarithmic spiral convex in the direction of rotation of the rotor, given in polar coordinates of the xOu plane by expression (1).

where r ₀ is the distance of the starting point A of the cutting edge ABC of the blade 11 from the axis Oz of rotation of the rotor 2,

φ is the polar angle defining the direction of the radius vector OB, the end of which sets the position of point B of the cutting edge ABC of the blade 11,

ρ is the length of the radius vector of the OB of point B of the cutting edge ABC of the blade 11 corresponding to the polar angle φ,

β _r - the angle of snow cutting by the cutting edge ABC of the blade 11, equal to the angle of inclination of the cutting edge ABC,

e is the basis of natural logarithms,

φ ₂ is the polar angle corresponding to the end point C of the cutting edge ABC of the blade 11.

The plane α perpendicular to the axis Oz of rotation of the rotor 2. The plane α intersects the axis Oz of rotation of the rotor 2 at the point O ₁ at a distance - h from point O, where h is the height of the blade. A system of polar coordinates was introduced in the plane α, the pole of this coordinate system coinciding with the point O ₁ , and the polar axis O ₁ s rotated by an angle δ> 0 relative to the axis O ₁ x ₁ parallel to the axis Ox. As a positive direction of rotation of the radius vector, which sets the position of the point in the specified polar coordinate system, the direction of rotation is clockwise.

Line A ₁ B ₁ C ₁ pairing of the blade 11 and the disk base 12 lies in the plane α. The line A ₁ B ₁ C _{1 of the} pairing of the blade 11 and the disk base 12 has the form of a section of a logarithmic spiral convex in the direction of rotation of the rotor, given in polar coordinates of the plane α by expression (2).

where r ₀₁ is the distance of the starting point A _{1 of the} line A ₁ B ₁ C ₁ pairing of the blade 11 and the disk base 12 from the axis Oz of rotation of the rotor 2,

φ ₁ is the polar angle defining the direction of the radius vector O ₁ B ₁ , the end of which sets the position of point B _{1 of the} line A ₁ B ₁ C ₁ pairing of the blade 11 and the disk base 12,

ρ ₁ is the length of the radius vector O ₁ B _{1 of the} point B _{1 of the} line A ₁ B ₁ C _{1 of} conjugation of the blade 11 and the disk base 12 corresponding to the polar angle φ ₁ ,

φ ₁₂ is the polar angle corresponding to the end point C _{1 of} the interface line of the blade 11 and the disk base 12.

The selection of the quantities δ, r ₀ and r ₀₁ provides the inclination of the blade 11 relative to the base of the rotor 12 by an angle less than 90 °. A decrease in r ₀₁ provides an increase in the slope at constant h, δ, and r ₀ .

The ABC and A ₁ B ₁ C ₁ lines are used as guide lines when constructing the surface of the blade. When φ changes from 0 to φ ₂ , point B moves along the ABC curve from point A to point C. Similarly, when φ ₁ changes from 0 to φ _12, point B ₁ moves along the curve A ₁ B ₁ C ₁ from point A ₁ to point C ₁ . The surface of the blade is formed when the straight segment BB ₁ moves, when φ and φ ₁ change from 0 to φ ₂ and the current values of φ ₁ are equal to φ. If the current values of φ ₁ and φ are equal, the tangents BD and B ₁ D _{1 are} parallel. And this ensures that the surface of the blade constructed in this way can be deployed on a plane. The parameters determining the shape of the blade: r ₀ , r ₀₁ , h, β, δ. When φ ₁ is not equal to φ ₁₂ , part of the theoretically constructed blades protruding beyond the dimensions of the working chamber 1 should be removed.

Guide shields 3 - sections of the conical surface. The axis of this cone coincides with the axis OO ₁ in figure 2. The guide plate 14 is removable to enable mounting of the rotor.

Face AA ₁ blades (see Fig.6) can be extended to connect with the same face of one of the adjacent blades by the site-insert of the surface, unfolding on a plane. Then two adjacent blades can be made of flat sheet material as one part. The insertion site can be constructed similarly to the construction of the surface of the scapula. Cubic parametric curves in the Ferguson form [4] can be used as guide lines when constructing the insertion site. Figure 7 shows the projection of two blades 11 and 11 'on the disk base 12 of the rotor connected by an insert section. CBAA ₁ B ₁ C ₁ - shoulder blade 11 '. EDD ₁ E ₁ - blade 11 '. AA ₁ D ₁ D - section-insert. Curves CBA and DE are the cutting edges of the blades 11 and 11 ', respectively. Curves C ₁ B ₁ A ₁ and D ₁ E ₁ are the mating lines with the base of the rotor 12 of the blades 11 and 11 ', respectively. In the manufacture of each blade blank in the form of a single piece, combining two adjacent blades and an insert section, it becomes possible to use thinner sheet material for manufacturing the blades, because in this case, each blade is assembled from two blanks.

Snow removal unit operates as follows. A smaller than 90 ° angle of constant snow cutting by the cutting edge of the blades 11 and an inclination of the blades relative to the base 12 by an angle less than 90 ° provide an effective grip of snow by the blades 11. The inclination of the blades 11 relative to the base 12 by an angle less than 90 ° in the direction of rotation of the rotor provides an effective the movement of snow in the direction of the base of the rotor 12. A smaller than 90 ° angle of inclination of the curve obtained by the intersection of the surface of the blade and the plane perpendicular to the axis of rotation of the rotor on the surface of each blade 11, provides the effective movement of snow in the radial direction from the axis of rotation of the rotor OO ₁ and the movement of snow a considerable distance through the outlet 13 of the working chamber 1 due to the presence of component F _dr pressure force F _d Because the upper part of the rotor is covered with vertical walls of the working chamber, the snow scatter during rotation of the rotor is minimal.

The advantages of the claimed design:

- the bending of the blades in a shape close to the shape of a logarithmic spiral, provides increased productivity of the snow removal unit due to the effective cutting and movement of snow,

- the shape of the blades is completely determined by the shape of the contact line of the blades and the disk base of the rotor,

- the installation of the blades at an angle less than 90 ° to the disk base provides an intensive grip of snow and its supply to the working chamber,

- the manufacture of rotor blades of sheet material provides a low cost of the rotor,

- the rotor is mounted directly on the motor shaft, i.e. there is no need to use a transmission mechanism that increases the complexity of the product and increases the energy loss.

Information sources

1. US 4150501 A (MORE CORP.), 04.24.1979.

2. US 2,785,482 A (CROCE et al.), 03/19/1957.

3. SU 956691 A (TSNIPKTI), 09/07/1982.

4. Foke A., Pratt M. Computational geometry. Moscow, Mir, 1982.

Claims (4)

1. A small-sized snow removal unit consisting of a chassis on which an engine, a casing covering the engine, a cylindrical working chamber with a rotor and an outlet are installed, guiding shields, engine controls, and the rotor is mounted on the motor shaft and consists of a disk base perpendicular to the axis rotation of the motor shaft and blades, characterized in that the blades are curved from a flat sheet material, the line of intersection of each blade with any plane perpendicular to the axis of rotation of the rotor is close to the shape of the section of the logarithmic spiral convex in the direction of rotation of the rotor, the blades are installed with an inclination with respect to the disk base so that the angle between the blade and the disk base in the direction of rotation of the rotor is less than 90 °, and attached to the disk base along the interface line having the shape of the section a logarithmic spiral convex in the direction of rotation of the rotor, the cutting edge of each blade has the shape of a plot of a logarithmic spiral convex in the direction of rotation of the rotor. 2. Small-sized snow removal unit according to claim 1, characterized in that each blade blank is made in the form of one part, combining two adjacent blades and an insert section, two neighboring blades are made of flat sheet material in the form of one part. 3. Small-sized snow removal unit according to any one of claims 1 and 2, characterized in that it is equipped with handles for moving the unit during operation and for carrying it. 4. Small-sized snow removal unit according to claim 3, characterized in that the engine controls are mounted on the handle to move the unit during operation.

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