WO2019130317A1

WO2019130317A1 - Spraying rotor

Info

Publication number: WO2019130317A1
Application number: PCT/IL2018/051411
Authority: WO
Inventors: Gerardo R. MARCHESINI; Walter Daniel SEQUEIROS MOYANO
Original assignee: Centro De Innovacion Tecnologica Empresarial Y Social (Cites) S.A.; Dr. Eyal Bressler Ltd
Priority date: 2017-12-31
Filing date: 2018-12-30
Publication date: 2019-07-04
Also published as: AR114067A1

Abstract

A device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle comprises a rotatable shaft connectable to a drive. The rotatable shaft has an internal axisymmetric passage connectable to a container accommodating the material to be dispensed. The internal axisymmetric passage is configured for conducting the material there through. The rotatable rotor further comprises at least one pipe radially arranged relative to the rotor shaft and rotatable therewith. The pipe is fluidly connected to the internal passage of the rotor shaft. The pipe is provided with nozzles at terminals thereof configured for dispensing the material of interest.

Description

SPRAYING ROTOR

FIELD OF THE INVENTION

The present invention relates to devices for applying gas, liquid, gas-liquid and suspension materials in an aerial manner and, more particularly, to a rotor which sprays agrochemical due to centrifugal force acting thereon. The present invention also relates to aerial vehicles having at least one spraying rotor as a lifting propeller.

The present invention has application in of rotating wing UAVs with electric motors of fixed pitch propellers and rotating wing UAVs with electric motors or combustion engines with variable pitch propellers.

BACKGROUND OF THE INVENTION

Devises configured for sprinkling or spraying water or agrochemicals based on rotational movement are known in the art. For example, US 6138924 discloses a rotor-type sprinkler which dispenses water in irrigational systems. A rotary member is driven by water flow to be dispensed.

GB 840679 discloses a helicopter rotor having jet-propulsion units mounted side by side in helicopter rotor blades. Combustion products are exhausted from the blades and propel them and create a lifting force.

The described technical solutions are characterized by a fluid (water or combustion products) which drives the rotor by its kinetic energy. Nowadays, a lot of rotary wing vehicles are used for applying agrochemicals in agriculture. Hence, there is a long- felt and unmet need to provide a device utilizing rotational energy for spraying agrochemicals over agriculturally used areas.

SUMMARY OF THE INVENTION

It is hence one object of the invention to disclose a device mountable on an aerial vehicle for dispensing a material of interest during operation of the aerial vehicle. The device comprises a rotatable shaft connectable to a drive. It is a core purpose of the invention to provide the rotatable shaft having an internal axisymmetric passage connectable to a container accommodating the material to be dispensed. The internal axisymmetric passage is configured for conducting the material therethrough. The rotor further comprises at least one pipe radially arranged relative to the rotor shaft and rotatable therewith; the pipe is fluidly connected to the internal passage of the rotor shaft; the pipe is provided with nozzles at terminals thereof configured for dispensing the material of interest.

Another object of the invention is to disclose the device comprising at least two rotor blades connected to the shaft and rotatable therewith.

A further object of the invention is to disclose at least two pipes which are at least partially embedded into the at least rotor blades in an individual manner.

A further object of the invention is to disclose the aerial vehicle which is an unmanned.

A further object of the invention is to disclose the shaft kinematically connected to said drive by a transmission arrangement selected from the group consisting of a pulley-belt arrangement, a cardan arrangement, conical cogwheel arrangement and any combination thereof.

A further object of the invention is to disclose the aerial vehicle selected from the group consisting of a helicopter, a coaxial, an autogyro, and a multi-copter.

A further object of the invention is to disclose the shaft provided with a shaft seal connected to the container by a feeding pipe.

A further object of the invention is to disclose the state of the material of interest selected from the group consisting of an insecticide, an herbicide, a fungicide, a nematicide, a fertilizer, a hormone, a growth regulator, a biostimulant, a pollen, an adjuvant, a molluscicide and any combination thereof.

A further object of the invention is to disclose the device comprising a shutoff/control valve configured to control a flow of said material of interest dispensed via said nozzles.

A further object of the invention is to disclose a method of dispensing a material of interest from an aerial vehicle during operation thereof. The aforesaid method comprises steps of: (a) providing a device mountable on an aerial vehicle for dispensing a material of interest during operation of the aerial vehicle; the device comprising a rotatable shaft connectable to a drive; the rotatable shaft has an internal axisymmetric passage connectable to a container accommodating the material to be dispensed; the internal axisymmetric passage is configured for conducting the material therethrough; the rotor further comprises at least two pipes radially arranged relative to the rotor shaft and rotatable therewith; the pipes have first and second terminals; the first terminals of the pipes are connected to the internal passage of the rotor shaft; the second terminals are provided with dispensing nozzles; (b) rotating the shaft; (c) dispensing the material of interest from the nozzles by means of centrifugal force applied thereto.

A further object of the invention is to disclose the method comprising electrostatically attracting droplets of the material of interest dispensed from the nozzles to cultivated plants due to positively friction charging the droplets during the step dispensing the material of interest and a negative charge carried by the cultivated plants.

During the flight of an air vehicle that uses rotating wings (propellers) for lift, there is a downward air flow produced by these propellers. The spray system of this invention uses this air flow to transport the droplet coming out from the propeller directly to the ground. The nozzle in the propellers is located to obtain the best trajectory for the correct impact in the crop. The flow rate and droplet size can be calibrated according to the duct hydraulic diameter, working RPM, exit restriction (nozzle), location and direction of release within the propeller blade in this way, different propellers can be used for different types of sprays.

Inside the inner conduit of the propeller the fluid undergoes variations of pressure which can cause vaporization when this pressure is less than the pressure of the fluid in gaseous state at the given temperature. To avoid this effect, restrictions are placed on the nozzles that maintain the pressures elevated enough along the conduit. These nozzles also maintain a stable flow rate, attenuating the variations caused by the difference in revolutions of the propellers during the flight.

At the moment of release, the droplets acquire the tangential speed produced by the angular velocity of the propellers, this velocity separates the droplet from the propeller and diverts it from the drone’s main air flow. To control the absolute velocity of the droplet, the nozzle can be directed so that the velocity produced by the pressure gradient in the internal duct reduces the tangential velocity given by the blade at the moment of detachment and improves the spray cone. turbine

A further object of the invention is to disclose a device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle. The aforesaid device comprises at least one rotatable shaft connectable to a drive of said aerial vehicle. The rotatable shaft carries a lifting rotor. The device comprises a turbine pump mechanically connected to the rotatable shaft. The turbine pump has an inlet port connectable to a container accommodating the material to be dispensed and an outlet port being in a fluid connection with nozzles at terminals thereof configured for dispensing the material of interest.

A further object of the invention is to disclose a method of dispensing a material of interest from an aerial vehicle during operation thereof. The aforesaid method comprises steps of: (a) providing a device mountable on an aerial vehicle for dispensing a material of interest during operation of the aerial vehicle; the device comprising at least one rotatable shaft connectable to a drive of said aerial vehicle; the rotatable shaft carrying a lifting rotor; the device comprises a turbine pump mechanically connected to the rotatable shaft; the turbine pump has an inlet port connectable to a container accommodating said material to be dispensed and an outlet port being in a fluid connection with nozzles at terminals thereof configured for dispensing the material of interest; (b) rotating said at least one rotatable shaft; (c) dispensing the material of interest from said nozzles by means of pumping the material of interest into said nozzles.

The turbine, located in the base of the engine, drives the fluid through fixed nozzles (non-rotational). In this case, the fluid does not acquire the tangential velocity like in the previous versions. With this configuration a more accurate spray, with less drift, is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments are adapted to now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Fig. 1 is a cross-sectional view of a rotor with blades characterized by a fixed pitch;

Fig. 2 is a cross-sectional view of a rotor provided with a pulley;

Fig. 3 is a top view of a rotor arrangement driven by conical sprockets;

Fig. 4 is a cross-sectional view of a rotor mountable on an electric motor having a hollow shaft;

Fig. 5 is a schematic diagram of an electric UAV carrying a spraying arrangement;

Figs 6 and 7 are high-speed photographs of microdroplet generation from outlet nozzles;

Fig. 8 is a graph of dependence of flow rate within nozzles of different diameter ratios on RPM;

Fig. 9 is a graph of dependence of minimum pressure in the duct within nozzles of different diameter ratios on RPM

Figs 10A and 10B present iso-velocity surfaces obtained from exemplary simulations of the velocity field below an octocopter drone showing high speed zones and area of influence of the airflow;

Figs 1 1 A and 11 B present 3D particle dispersions over their dimension within the airflow shown in Figs 10A and 10B, respectively;

Figs 12A and 12B presents overall and exploded views of a second embodiment the spray propeller; and

Fig. 13 presents a schematic view of a combustion engine UAV carrying a spraying arrangement with hydraulic turbine connected to each power transmission axes.

DETAILED DESCRIPTION OF THE INVENTION

The following description is provided, so as to enable any person skilled in the art to make use of said invention and sets forth the best modes contemplated by the inventor of carrying out this invention. Various modifications, however, are adapted to remain apparent to those skilled in the art, since the generic principles of the present invention have been defined specifically to provide a device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle and a method doing the same. The present invention is directed to minimize a flying weight of the UAV and energy consumed for spraying agrochemicals. A standard known spraying system comprises a hydraulic pump feeding a liquid to nozzles which produce droplets characterized by the predetermined proper size and velocity. According to the present invention, the agrochemicals are sprayed under action of a centrifugal force when a rotor rotates. The present invention is applicable to a lifting rotor of any type of aerial vehicles.

Reference is now made to Fig. 1 , presenting a cross-sectional view of rotor 100a mountable on electric motor 50. The engine support 70 with a preload chamber 75 that prevent the fluid leaking with a fluid seal 65 to prevent entry into the bearing 60 which facilitates the movement of the shaft.

Hollow shaft 45 of motor 50 is connected to inlet pipe connector 40 via the fluid seal 65 and the preload chamber 75 accommodating agrochemicals to be sprayed (not shown). Hollow shaft 45 is in a fluid communication with preload chamber 75 and is rotatable independently therefrom. Blades 10 have a fixed pitch. Passages 25 are embedded into blades 10 and fluidly connected by means of one terminal to hollow shaft 45 while another terminal is provided with nozzle 20 which generates droplets 30.

Reference is now made to Fig. 2, showing a cross-sectional view of rotor 100b having bevel gear transmission 90 driven by a cardan shaft (not shown) . A fluid seal 65 is placed to prevent the fluid leaking, and avoiding entry into the bearing 60 which facilitates the movement of the shaft. Blades 10 are mounted by means of blade holders 70. Passages 25 within blades 10 are connected to hollow shaft 45 by means of bifurcated pipes 80 such that the blade pitch is variable. Thus, the agrochemicals are fed to nozzles via successively mounted inlet pipe connector 40, preload chamber 75, hollow shaft 45, pipes 80 and internal passages 25.

Reference is now made to Fig. 3, showing a top view of an alternative embodiment 100d of the present invention. Transmission mechanism 100d comprises a plurality of sprockets including conical ones. Use of cardan joints is also in the scope of the present invention (not shown in Fig. 3). Numeral 73 refers to a driving sprocket which is engaged with central sprocket 75. Secondary sprockets 77 have both straight cut and conical portions. The straight cut portion is in a kinematic link with central sprocket 73, while the conical portion is engaged with one of conical gear 82 which another conical gear 82 via shaft 85. The kinematic link between conical gears 82 can include a cardan joint. Sprockets 87 transfer the rotational motion to propellers 10.

Reference is now made to Fig. 4, showing a cross-sectional view of rotor 100c having passages 27 mounted contrary to the embodiment 100a in Fig.1 outside blades 10.

Reference is now made to Fig. 5, presenting an exemplary embodiment of UAV 200 which comprises container 1 10 accommodating an agrochemical to be sprayed. Numeral 140 refers to an UAV body. Rotors 100a provided with electric motors are mounted on corbels 130 connected to UAV body. The agrochemicals are fed from container via pipes 120.

As shown in Figs 6 and 7 constituting high speed photographs, the agrochemical when dispensed from nozzles is converted into droplets. Airflow facilitates creating droplets of a predetermined size and impart a predetermined velocity to them.

Reference is now made to Fig. 8, showing that the flow that circulates through the duct increases with the RPM, and with the outlet diameter of the reduction nozzle, so there is a minimum value for the combination of both that meets the flow requirement (represented by a solid black line).

Reference is now made to Fig. 9, showing that the minimum pressure inside the tube decreases with the increase in the RPM, and with the outlet diameter of the reducing nozzle, so there is a maximum value for the diameter of the outlet restriction in the nozzle which ensures that the liquid will not be evaporated anywhere along the duct in the established range of RPM's. The crosses represent isoflow curves. The black horizontal solid line represents the vapor pressure of water at 50°C as a reference. Fig. 9 also shows that as the outlet diameter decreases the flow rate becomes more independent on the RPM of the blades. Therefore, to obtain an irrigation as independent as possible from the working RPM, and therefore as uniform as possible, it would be advisable to use the nozzle with the smallest possible exit diameter.

Reference is now made to Figs 10A and 10B showing the average velocity field in the environment of an octocopter in an exemplary manner. Particles of different sizes are injected onto this velocity field, whose course can be observed in Figs 1 1 A and 1 1 B, respectively. All the simulations have been performed using OpenFOAM C++ toolbox.

The particles in blue, which have a diameter of 0.1 mm, are quickly dragged by the downward flow under the rotors, losing their initial momentum, reaching the soil at a radius of 1.5 meters from the center of the drone.

The particles in red have a diameter of 0.5 mm, and due to their inertia, they quickly move away from the drone and the high velocity flow area, finally falling by gravity in a radius of 3.5 to 4.5 meters from the center of the drone (area painted in red)

This result reveals the high dependence of the dispersion with the droplet size and therefore with the nozzle outlet diameter relative to the diameter of the duct. It should be noted that for droplets with a diameter less than 0.1 mm, the movement is entirely dominated by the air flow under the rotors, that is, a nozzle choice that generates droplets smaller than 0.1 mm ensures low dispersion and more precise and controlled spray.

According to the present invention, a device mountable on an aerial vehicle for dispensing a material of interest during operation of the aerial vehicle is disclosed. The device comprises a rotatable shaft connectable to a drive.

Reference is now made to Figs 12A and 12B presenting overall and exploded views of a second embodiment the spray propeller, respectfully. The brushless motor 12- 02 of a drone includes in its lower part a hydraulic turbine 12-03 coupled to the solid shaft 12-04 that is connected to the propeller 12-01 that drives the UAV during the flight. The turbine 12-03 is contained in the support base 12-06 of the engine provided with the nozzles 12-05 for spraying that do not rotate with the engine and release the fluid without tangential velocity. The embodiment shown in Fig.12 allows using the rotation of the propeller shafts to drive the fluid by means of an impeller or turbine attached to the shaft avoiding tangential velocity components on the droplets when detaching the nozzles. Reference is now made to Fig. 13 The internal combustion engine 13-01 of an UAV with pitch control includes a hydraulic turbine 13-02 connected to its axis that drives the fluid from the tank 13-03 by means of hydraulic conduits 13- 04 to nozzles 13-05. The engine 13-01 transmits the power to the rotors with blades provided with pitch control 13-06 to achieve the flight with the variation of angle of attack of the blades

13-07

It is a core feature of the invention to provide the rotatable shaft having an internal axisymmetric passage connectable to a container accommodating the material to be dispensed. The internal axisymmetric passage is configured for conducting the material therethrough. The rotor further comprises at least one pipe diametrically arranged relative to the rotor shaft and rotatable therewith; the pipe is fluidly connected to the internal passage of the rotor shaft; the pipe is provided with nozzles at terminals thereof configured for dispensing the material of interest.

According to another embodiment of the present invention, the device comprises at least two rotor blades connected to the shaft and rotatable therewith.

According to a further embodiment of the present invention, at least two pipes which are at least partially embedded into the at least rotor blades in an individual manner.

According to a further embodiment of the present invention, the aerial vehicle is an unmanned.

According to a further embodiment of the present invention, the shaft drive is selected from the group consisting of to an electric motor and an internal combustion engine.

According to a further embodiment of the present invention, the shaft is kinematically connected to said drive by a transmission arrangement selected from the group consisting of a pulley-belt arrangement, a cardan arrangement, conical cogwheel arrangement and any combination thereof.

According to a further embodiment of the present invention, the aerial vehicle is selected from the group consisting of a helicopter, a coaxial, an autogyro, and a multi-copter. According to a further embodiment of the present invention, the shaft is provided with a shaft seal connected to the container by a feeding pipe.

According to a further embodiment of the present invention, the state of the material of interest is selected from the group consisting of an insecticide, an herbicide, a fungicide, a nematicide, a fertilizer, a hormone, a growth regulator, a biostimulant, a pollen, an adjuvant, a molluscicide and any combination thereof.

According to a further embodiment of the present invention, the device comprises a shutoff valve configured to control a flow of said material of interest dispensed via said nozzles.

According to a further embodiment of the present invention, a method of dispensing a material of interest from an aerial vehicle during operation thereof is disclosed. The aforesaid method comprises steps of: (a) providing a device mountable on an aerial vehicle for dispensing a material of interest during operation of the aerial vehicle; the device comprising a rotatable shaft connectable to a drive; the rotatable shaft has an internal axisymmetric passage connectable to a container accommodating the material to be dispensed; the internal axisymmetric passage is configured for conducting the material therethrough; the rotor further comprises at least one pipe radially diametrically arranged relative to the rotor shaft and rotatable therewith; the pipe is fluidly connected to the internal passage of the rotor shaft; the pipe is provided with nozzles at terminals thereof configured for dispensing the material of interest; (b) rotating the shaft; (c) dispensing the material of interest from the nozzles by means of centrifugal force applied thereto.

According to a further embodiment of the present invention, the method comprises electrostatically attracting droplets of the material of interest dispensed from the nozzles to cultivated plants due to positively friction charging the droplets during the step dispensing the material of interest and a negative charge carried by the cultivated plants.

According to a further embodiment of the present invention, a device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle is disclosed. The aforesaid device comprises at least one rotatable shaft connectable to a drive of said aerial vehicle. The rotatable shaft carries a lifting rotor. The device comprises a turbine pump mechanically connected to the rotatable shaft. The turbine pump has an inlet port connectable to a container accommodating the material to be dispensed and an outlet port being in a fluid connection with nozzles at terminals thereof configured for dispensing the material of interest.

According to a further embodiment of the present invention a method of dispensing a material of interest from an aerial vehicle during operation thereof is disclosed. The aforesaid method comprises steps of: (a) providing a device mountable on an aerial vehicle for dispensing a material of interest during operation of the aerial vehicle; the device comprising at least one rotatable shaft connectable to a drive of said aerial vehicle; the rotatable shaft carrying a lifting rotor; the device comprises a turbine pump mechanically connected to the rotatable shaft; the turbine pump has an inlet port connectable to a container accommodating said material to be dispensed and an outlet port being in a fluid connection with nozzles at terminals thereof configured for dispensing the material of interest; (b) rotating said at least one rotatable shaft; (c) dispensing the material of interest from said nozzles by means of pumping the material of interest into said nozzles.

Said fluid flows from the container through the turbine to the fixed nozzles (non- rotationa!). In this case, the fluid does not acquire the tangential velocity like in the previous embodiments. With this configuration a more accurate spray, with less drift, is obtained.

Claims

CLAIMS:

1. A device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle; said device comprising a rotatable shaft connectable to a drive; wherein said rotatable shaft has an internal axisymmetric passage connectable to a container accommodating said material to be dispensed; said internal axisymmetric passage is configured for conducting said material therethrough; said rotor further comprises at least one pipe radially arranged relative to said rotor shaft and rotatable therewith; said pipe is fluidly connected to said internal passage of said rotor shaft; said pipe is provided with nozzles at terminals thereof configured for dispensing said material of interest.

2. The device according to claim 1 comprising at least two rotor blades connected to said shaft and rotatable therewith.

3. The device according to claim 2, wherein said at least two pipes are at least partially embedded into said at least rotor blades in an individual manner.

4. The device according to claim 1 , wherein said aerial vehicle is an unmanned.

5. The device according to claim 1 , wherein said drive is selected from the group consisting of an electric motor and an internal combustion engine.

6. The device according to claim 1 , wherein said shaft is kinematically connected to said drive by a transmission arrangement selected from the group consisting of a pulley-belt arrangement, a cardan arrangement, conical cogwheel arrangement and any combination thereof.

7. The device according to claim 2, wherein said aerial vehicle is selected from the group consisting of a helicopter, a coaxial, an autogyro, and an n-copter.

8. The device according to claim 1 , wherein said shaft is provided with a shaft seal connected to said container by a feeding pipe.

9. The device according to claim 1 comprising a shutoff valve configured to control a flow of said material of interest dispensed via said nozzles.

10. The device according to claim 1 , wherein a state of said material of interest is selected from the group consisting of an insecticide, an herbicide, a fungicide, a nematicide, a fertilizer, a hormone, a growth regulator, a biostimulant, a pollen, an adjuvant, a molluscicide and any combination thereof.

1 1. A method of dispensing a material of interest from an aerial vehicle during operation thereof; said method comprising steps of:

a. providing a device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle; said device comprising a rotatable shaft connectable to a drive; said rotatable shaft has an internal axisymmetric passage connectable to a container accommodating said material to be dispensed; said internal axisymmetric passage is configured for conducting said material therethrough; said rotor further comprises at least one pipe radially arranged relative to said rotor shaft and rotatable therewith; said pipe is fluidly connected to said internal passage of said rotor shaft; said pipe is provided with nozzles at terminals thereof configured for dispensing said material of interest;

b. rotating said rotatable shaft;

c. dispensing said material of interest from said nozzles by means of centrifugal force applied thereto.

12. The method according to claim 11 comprising electrostatically attracting droplets of said material of interest dispensed from said nozzles to cultivated plants due to positively friction charging said droplets during said step dispensing said material of interest and a negative charge carried by said cultivated plants.

13. A method which utilizes a hydraulic turbine integral with the shaft that drives the propeller system of the UAV to pump any material of interest using the air flow generated by the UAV.

14. An electric motor or internal combustion engine for UAV that integrates a hydraulic pump for the delivering of fluid during the flight.

15. A device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle; said device comprising at least one rotatable shaft connectable to a drive of said aerial vehicle; said rotatable shaft carrying a lifting rotor wherein said device comprises a turbine pump mechanically connected to said rotatable shaft; said turbine pump has an inlet port connectable to a container accommodating said material to be dispensed and an outlet port being in a fluid connection with nozzles at terminals thereof configured for dispensing said material of interest.

16. A method of dispensing a material of interest from an aerial vehicle during operation thereof; said method comprising steps of:

a. providing a device mountable on an aerial vehicle for dispensing a material of interest during operation of said aerial vehicle; said device comprising at least one rotatable shaft connectable to a drive of said aerial vehicle; said rotatable shaft carrying a lifting rotor; said device comprises a turbine pump mechanically connected to said rotatable shaft; said turbine pump has an inlet port connectable to a container accommodating said material to be dispensed and an outlet port being in a fluid connection with nozzles at terminals thereof configured for dispensing said material of interest;

b. rotating said at least one rotatable shaft;

c. dispensing said material of interest from said nozzles by means of pumping said material of interest into said nozzles.