FLUID ENERGY CONVERTER
A fluid energy converter includes: a rotatable U-shaped rim rack having a raised along-edge wall forming a rail, a rotatable cylindrical frame and a plurality of vertical rectangular blades uniformly distributed and rotatably mounted in the frame. Each blade includes rollers alternately sliding in the recessed rail. The U-shape of the rim rack forms a hollow chamber in which a portion of the frame is received. The blades mounted in the frame are allowed to revolve about an arbor of the frame and at the same time, with the rollers being guided by the rail of the rim rack, the blades spin about their own axes. Instead of mechanical control, the rail formed in the rim rack is defined by a curve that has unique mathematic characteristics to set each blade to an optimum angle for receiving wind power so as to reduce resistance and better action of force thereon.
The present invention generally relates to a fluid energy converter that utilizes fluid flow to generate rotational kinetic energy and uses the rotational kinetic energy to cause movement of fluid for flowing in a specific direction.
DESCRIPTION OF THE PRIOR ARTAn early vertical axis wind turbine (VAWT) was first patented by C. hand in 1846, of which the patent bearing a title of “Water wheel” was issued U.S. Pat. No. 4,517 on May 16, 1846. This invention provides blades that have one end coupled to an axle and an opposite end that is changeable in position for changing the angle of the blades in order to reduce resistance.
In the design of the above discussed water wheel, the axle is coupled to multiple pairs of arms that extend radially. Each pair of arms carries a blade at ends thereof with the blade being pivotable. When the blade that takes a force is rotated about the axle by 180 degrees, the blade itself rotates by 90 degrees in order to reduce the resistance. During the rotation of the blade about the axle, the blade is also allowed to rotate about its own axis, whereby various angles may be dynamically formed between the blades and the fluid flow in order to reduce resistance and provide improved action of force.
This type of arrangement that the blades are rotating about their own axes when rotated about a primary axle was known as early as the teaching given in a U.S. patent issued to C. R. Gutting on 1906, of which the title is “Wind Wheel” (U.S. Pat. No. 809,431 issued on Jan. 9, 1906). With the arrangement of a complicated mechanism, when blades are rotated about a central shaft, the blades also rotate about their own axes, whereby various angles are dynamically formed between the blades and wind to reduce the resistance and improve action of force.
In 1907, C. F. Whisler was issued a U.S. patent, called “Wind Wheel” (U.S. Pat. No. 862,299 issued on Aug. 6, 1907). This is also an invention of the above discussed type, and this invention uses sprocket wheels and a chain to cause blades to rotate about their own axes when the blades are rotated about a central shaft, whereby the same result can be obtained.
What is concerned in the present invention is how to make blades rotating about their own axes when the blades are rotated about a central shaft in order to reduce resistance and improve action of force. Many inventors proposed different solutions to address such an issue. Some of the recent prior art references are listed as follows:
In 2010, Eldon L. Stroburg was issued a U.S. patent, called “Windmill with Pivoting Blades” (U.S. Pat. No. 7,766,602 issued on Aug. 3, 2010). This invention utilizes a gear train to cause blades to rotate about their own axes when the blades are rotated about a central axis in order to dynamically set the angles between the blades and wind. The same result can be obtained.
In 2008, a Taiwan Patent Application disclosed a blade set of vertical wind power generator and a method for coupling variable winding for wind power generator (Taiwan Patent Publication No. 2008339453 published on Aug. 16, 2008). The legal status of the application is publication and teaches use of adjustable link bars to cause blades to rotate about their own axes when the blades are rotated about a central axis. Again, the same result can be obtained.
In 2010, a US Patent Application, called “Wind and Water Turbine” and owned by Lester Hostetler, was published (US Publication No. 2010/0060008 A1 published on Mar. 11, 2010). The legal status of this application is publication. When blades are rotated about a central shaft, an elliptic channel is set up inside a circular channel along which the blades rotate about the central shaft. A mechanism switch is provided outside the channel, whereby the mechanical switch forces rollers of the blades to alternately enter the channel. The elliptic channel inside the circular channel along which the blades rotate about the central shaft causes the blades to rotate about their own axes so as to dynamically set various angles between the blades and wind and provide the same result.
SUMMARY OF THE INVENTIONAn objective of the present invention is to provide a fluid energy converter that reduces resistance and generates improved result of force action.
To achieve the objective, the solution adopted in the present invention is as follows:
A fluid energy converter comprises a rotatable rim-like rack, or simply rim rack hereinafter, having a U-shaped cross-section and having a raised along-edge wall having an end surface that is recessed to form a channel serving as a rail; and a rotatable frame that carries a plurality of blades each of which is mounted to the frame in a rotatable manner and each having an upper edge having opposite ends to which rollers are mounted for sliding in the rail channel of the rim rack. Flow energy of a fluid may be employed to cause motion of the blades and the motion of the blades drives the frame to rotate thereby generating kinetic energy. Oppositely, rotational kinetic energy of the frame can be used to cause motion of the blades and the motion of the blades causes a fluid to move. The rail channel of the wheel rim guides the movement of the blades, making the movement of the blades showing the greatest efficiency.
The rotational motions of the frame and the wheel rim have a common rotation center, which, for easy description herein, will be referred to as “revolution axis”. Each blade has a center line that serves as a rotation center of the spinning of the blade about its own axis and will be referred to as “spin axis” herein. It is noted here that all the rotating interfaces found in the present invention are supported by bearings in order to reduce the frictional force.
The rotatable frame comprises multiple pairs of support arms, and the two support arms of each are arranged, in a symmetrical manner, at upper and lower sides of the frame. The distal ends of the support arms of each pair support therebetween a rotatable blade, which has shoulders and feet to which rollers are respectively mounted in such a way that, when the blade spins, the blade rollers are slidable in a rail channel defined in a raised portion of the wheel rim. The frame has an arbor having outward projecting portions to serve as an interface for exchange between rotational energy of the frame and an external energy source.
The U-shaped rim-like rack is arranged above the rotatable frame and both are individually rotatable about the revolution axis. The raised along-edge portion of the rim rack exceeds the thickness of the upper support arms and this is a hollow chamber formed in the rim rack for accommodating the upper support arms of the frame. The raised along-edge portion of the rim rack forms a recessed rail channel. The rail channel has a depth that is sufficient to the rollers mounted to the shoulders of the blade. When the rollers are moved in the recessed rail channel, the blades are caused to spin. Thus, when the blades revolute about the revolution axis, the rollers mounted to the shoulders thereof are sliding in the rail and are guided by the rail to cause spinning of the blades, thereby changing the directions of the blades.
The recessed rail channel that is formed in the rim rack has an opening for receiving the entry of the rollers. The rail channel defines a curve of trace or locus that is of a special curve. Such a curve is similar to a tip of a cardioid of a polar coordinate system and no rail segment is arranged at and close to the tip to thereby serve as an entry opening for the rollers during the rotation of the blades. The curve of the rail channel adopted in the present invention is special mathematic characteristics, wherein at least one of the two rollers on the shoulders of each blade must be always kept on the recessed rail channel and the outer one of the rollers on the shoulders of the blade is always kept on the rail channel. When the blade rotates, the two rollers alternately enter the recessed rail, and at the moment when the two rollers interchangeably enter the rail, the two rollers are simultaneously on the recessed rail channel.
The blades revolute about the revolution axis with the frame and the rollers of the blade are guided by the rail to cause spinning of the blades. When the blades revolute by one full turn about the revolution axis, the blades also make a half turn of spinning. Revolution of 180 degrees makes spinning of 90 degrees and revolution of 90 degrees makes spinning of 45 degrees.
The curve of the rail channel is a symmetric smooth curve having an axis of symmetry When fluid enters in a direction perpendicular to the axis of symmetry, the fluid drives the blades to cause rotation of the frame. Being guided by the rail, the included angle of each blade and the fluid varies to provide the best result of force action for the frame.
The rim rack has a surface on which a direction mark is made to perpendicular to the symmetry axis of the rail channel and will be referred to as “flow direction mark” for easy description. When the flow direction mark of the rim rack is consistent with the inflow direction of fluid, the action of force applied to the frame by the fluid is the best for the rotational motion of the frame.
To receive the energy of the fluid, air rudders are mounted in the direction of the flow direction mark and the air rudders are driven by winds to have the flow direction mark of the rim rack consistent with the inflow direction of the fluid. Under this condition, the power of the fluid is the best for driving the rotational motion of the frame. Oppositely, to use the rotational kinetic energy to propel a fluid for flowing, the flow direction mark of the rim rack is set at a fixed direction so that the most efficient flow of the fluid in a flowing direction can be realized.
As to the conversion of flow energy of fluid, the present invention provides a design that requires no mechanical gears, links, or switches and that may drive blades to spin about their own axes so as to dynamically set an angle between each blade and the direction of wind to be a proper value. Instead, a rail formed according to dynamic geometric principle is adopted and the rail is located outside the circle of revolution motion of the blades. Also, a proper operation mechanism is provided so that when the blades rotate about a center of the mechanism, the rail guides the blades to spin to dynamically set the blades to maintain various included angles with respect to the direction of wind or air flow, whereby the fluid energy converter according to the present invention may reduce resistance and better the action of force applied thereto.
Such a design uses no chain, gear, or link to force the blades to spin and does not require mechanical switches that forcibly cause rollers of the blades to enter the rail. Instead, the geometry of a rail located outside the circular lotus of revolution of the blades to naturally guide the rollers of the blades to alternately enter the rail, allowing the blades to rotate and thus take the optimum direction and realizing the most efficient conversion of energy of fluid. In the present invention, the blades may have a maximum width that is close to the diameter of the frame. The number of the blades is generally not subjected to any limitation, but is associated with the width of the blades. The material that makes the blades is selected depending on the nature of the fluid used and can be for example a plate or a sail.
Fluid used can be compressible or incompressible. The conversion of fluid energy can be either receiving fluid energy and generating rotational kinetic energy or using rotational kinetic energy to drive fluid to flow. Different accessory or ancillary mechanism may be used for different applications.
Some local or partial modifications may be made on the essential mechanism of the present invention according to the nature of the fluid used and the direction of conversion and will be briefed as follows:
(1) For reception of energy of compressible fluid in small scale, air rudders may be mounted according to the direction of the flow direction mark provided on the rim rack to tract the rail on the rim rack so as to dynamically set various included angle between each blade and the direction of wind for reducing resistance and bettering action of force.
(2) For reception of energy of incompressible fluid or powerful fluid, to improve the strength of the device in order to take the powerful fluid, the structure of the device can be made symmetric between the upper and lower sides. Upper and lower ends of the arbor of the rotatable frame may be both provided with rim racks that are rotatable simultaneously and are both provided with rail channels. Rollers are respectively mounted to two shoulders and two feet of each of the blades. The rollers on the upper and lower sides of each blade are movable in the rails of the upper and lower sides. Similarly, fluid enters in the direction of the flow direction mark in order to reduce resistance and better action of force.
(3) For using kinetic energy to drive fluid to flow, the mechanism that is described above for receiving energy of incompressible or powerful fluid is operated in a reversed way. No air rudder is provided and the rim racks that comprise rails are provided and fixed with the flow direction mark on the rim rack aligning with the direction in which the fluid is to be driven to flow. Under the guidance of the rails, the blades take a motion that is the best for driving the fluid to flow.
(4) For receiving energy of compressible fluid in a large scale, the center axis of the fluid energy converter is defined by a vertically fixed hollow tower like shaft, wherein the hollow shaft provides a channel or space in which wires are received for mounting an alarm device thereon and to serve as a maintenance channel. The center axis of the frame is now formed as a sleeve that is fit over the center axis of the tower like shaft interfaced by bearings and an energy conversion unit is provided on an outward extension section of the sleeve of the frame. Such a large-scale compressible fluid energy receiving device comprises blades that are rectangular area-variable blades. The interior of each of the rectangular blades comprises a sail structure and an outer framework of the blade is a support structure that may contract and expand the sail.
The inventor has identifies a curve for the rail, in respect of mathematic equation and proofs, which satisfies the above discussed requirements. The mathematic proofs will be published in the article “Mathematics on a Windmill with Non-mechanical Control Pivoting Blades” of Journal of Tungnan University. In addition, the inventor also makes numerical and graphic simulation on computers to verify that the operation of the curved lotus of the basic mechanism according to the present invention is feasible and correct. Also, a prototype is also completed for verification. The mathematic characteristics of the curve will be described in the following and graphic simulation is provided in the drawings.
This curve contains a family of curves, Tw, and each individual curve Tw(r, s) contains two parameters, r and s. The parametric equation of Tw(r, s) is as follows:
x=(r+s/2)cos(t/3)cos(t)−(r−s/2)sin(t/3)sin(t)
y=(r+s/2)cos(t/3)sin(t)+(r−s/2)sin(t/3)cos(t)
where −(3/2)cos−1(−s/4r)≦t≦(3/2)cos(−s/4r) and r is the radius of the rotatable frame of the present invention, and more precisely, the distance from the center axis of the frame to the center axis of spinning of each blade; s is the width of the blade and more precisely, the distance between centers of left and right side rollers of the blade. The curve Tw(r, s) shows the following characteristics: having a radius r and being a circle O with the center located at the original point. For a line segment S having a length s<2r, when the middle point M of the line segment S is located on the circumference of the circle O and an end of the line segment S is on the curve Tw(r, s), then a line of incidence that is parallel to y axis generates a line of reflection with respect to the line segment S and a parallel vector of the line of reflection is tangential to the circle at point M, see
The description of the present invention given herein is provided for the purposes of illustration of the operation mechanism according to the present invention, not to explain complicated mathematic formula, so that only the mathematic equation of the curve that defines the rail is shown herein. Some descriptions of the drawings will be given as follows.
Then, it is illustrated the relationship and variation between the two rollers on the shoulders of the blade and the recessed rail in the process of rotation of the blades. The line segment S represents the blade. The line segment S has two ends respectively representing the two rollers on the shoulders of the blade. The curve Tw represents the recessed rail. It can be seen from
The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
To better explain the technical solution provided by the present invention, a detailed description will be given below with reference to embodiments of the present invention. The description given below, however, is provided only for illustration of a basic mechanism of the present invention and several modified embodiments thereof and the description should not be construed that the present invention is limited to such embodiments.
The present invention is applicable to compressible fluids or incompressible fluids to convert rotational kinetic energy into the energy of flowing fluid. However, under an opposite operation, the present invention may be used to convert flow energy of fluid into rotational kinetic energy
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Claims
1. A fluid energy converter, characterized by comprising: a rotatable rim rack having a U-shaped cross-section, the rim rack having a raised along-edge wall having a surface that is recessed to form a rail and a rotatable frame; the rotatable frame carrying a plurality of blades, the blades being mounted in a rotatable manner to the rotatable frame, each of the blades having an upper edge having opposite ends to which rollers are respectively mounted for sliding in the recessed rail of the rim rack; when fluid energy causes the blades to move, the movement of the blades drives the rotatable frame to rotate and generate kinetic energy; oppositely, rotational kinetic energy of the rotatable frame causes the blades to move and the movement of the blades causes motion of fluid; the recessed rail of the rim rack guides the blades to make the movement of the blades the most efficient.
2. The fluid energy converter according to claim 1, characterized in that the rotatable frame comprises multiple pairs of support arms respectively arranged at upper and lower ends in a symmetric manner; distal ends of each pair of support arms support a rotatable blade therebetween, the blade having shoulders and feet to which rollers are mounted, whereby when the blade spins, the rollers of the blade are respectively sliding in the recessed rail formed in the raised portion of the rim rack; the rotatable frame having an arbor having outward extensions to serve as an interface for exchange between the rotational kinetic energy of the rotatable frame and an external energy source.
3. The fluid energy converter according to claim 2, characterized in that the recessed rail of the rim rack is such that when the rotatable frame rotates, the recessed rail has an opening and the opening serves as an entry opening for the rollers when the blades spin; when the rotatable frame is rotated, the blades of the rotatable frame are caused to spin, the two rollers of the blade in motion are such that at least one of the rollers is kept on the recessed rails and the two rollers alternately enter the recessed rail; the rollers of the feet and the rollers of the shoulder dog the same motion; the two rollers, when interchangeably entering the recessed rail, are both kept on the recessed rail, when the rotatable frame rotates, under the guidance of the recessed rail, the blade themselves spin in such a way that when the blades revolve by a full turn about a center axis of the rotatable frame, the blades spin by half a turn, a revolution of 180 degrees makes spinning of 90 degrees, and a revolution of 90 degrees makes a spinning of 45 degrees.
4. The fluid energy converter according to claim 1, characterized in that the recessed rail has a lotus that is symmetric and smooth curve having an axis of symmetry, a flow direction mark is formed on a surface of the rim rack in a direction perpendicular to the axis of symmetry for facilitating positioning or mounting an air rudder or a tail vane; when fluid enters in the direction of the flow direction mark, an optimum action of force is provided for the blades of the frame; oppositely, by fixing the rim rack, when the rotatable frame rotates, the blades drive fluid to flow with a primary flowing direction having a positive component consistent with the flow direction mark.
5. The fluid energy converter according to claim 4, characterized in that an air rudder is mounted to the rim rack along the flow direction mark, flow of fluid driving rotation of the air rudder, making the flow direction mark of the rim rack consistent with the direction of fluid.
6. The fluid energy converter according to claim 1, characterized in that upper and lower sides of the rotatable frame both have a rim rack having a recessed rail mounted thereto; the upper and lower rim racks are completely symmetric and synchronously rotatable to form a dual-rim rack structure having two rim racks; shoulders and feet have rollers mounted thereto, the recessed rail of the rim rack is such that when the rotatable frame rotates, the recessed rail has an opening, the opening serving as an entry opening for the rollers when the blades spin; when the rotatable frame is rotated, the blades of the rotatable frame are caused to spin with the rotation of the rotatable frame, the two rollers of the blade in movement are such that at least one of the rollers is kept on the recessed rail and the two rollers alternately enter the recessed rail; the rollers of the feet and the rollers of the shoulders do the same motion; the two rollers, when interchangeably entering the rail, are both kept on the recessed rail, when the rotatable frame rotates, under the guidance of the recessed rail, the blade themselves spin in such a way that when the blades revolves by a full turn about a center axis, the blades spin by half a turn, a revolution of 180 degrees makes spinning of 90 degrees, and a revolution of 90 degrees makes a spinning of 45 degrees, the two rollers symmetrically slide in the recessed rails of the upper and lower rim racks; the dual-rim rack structure is composed of two parallel and symmetric rim racks and a link or shell connecting between portions of the two rim racks close to the openings of the recessed rails to ensure synchronization and symmetry of the two rim racks for bearing strong fluid motion.
7. The fluid energy converter according to claim 6, characterized in that the rim rack has a surface on which a flow direction mark is formed to facilitate positioning or mounting an air rudder or a tail vane, a bearing support is mounted outside a center point of the shell that connects the two rim racks of the dual-rim rack structure to control the rotation of the dual-rim rack structure so as to have the direction of the flow direction mark of the rim rack pointing to the direction in which the fluid is driven to flow.
8. The fluid energy converter according to claim 7, characterized in that the shell connecting the two rim racks of the dual-rim rack structure forms an upside down tray, the tray located simultaneously outside of the dual-rim rack structure at a location close to the opening of the recessed rail; to control the dual-rim rack structure to rotate, the flow direction mark is set in a direction of horizon and the tray is set above the dual-rim rack structure; to control the dual-rim rack structure to rotate, the flow direction mark is set in a direction of horizon and pointing toward the direction along which push is to be made, the tray being full of air therein to thereby serve as an efficient propeller for sailing on an incompressible fluid.
9. The fluid energy converter according to claim 5, characterized in that to perform a job of receiving energy of compressible fluid in a large scale, the fluid energy converter has a center axis that is divided into a vertically fixed hollow shaft, the hollow shaft receiving wires therein to have an alarm device mounted to an upper end thereof and forming a maintenance channel, the hollow shaft is such that an upper end thereof comprises a thrust bearing that bears the weight of the rim rack and a rack brake device that controls the rail mounted thereto; the hollow shaft has a lower end that comprises a thrust bearing that bears the weight of the frame, a frame brake device that controls the frame, and an energy conversion control chamber; the rotatable frame has a center axis that forms a sleeve, the sleeve being fit over the fixed axis with bearings as interface, the outward extensions of the arbor of the frame arbor being also a sleeve comprising an energy conversion unit, a brake drum, and thrust bearing.
10. The fluid energy converter according to claim 9, characterized in that the blades comprise area-adjustable blades; interior of the rectangular blade is constructed as a contractible/expandable sail structure, an outer framework of the blade being a support to the contractible/expandable sail structure; a lower edge of the sail is fixed to a lower support of the outer framework of the blade, the sail being supported by a plurality of horizontal sail bars, ascending and descending of an uppermost horizontal sail bar determines contraction and expansion of the sail; the outer framework of the said comprises a C-shaped channel structure, the C-shaped channel having an opening facing inward; each horizontal said bar of the sail has two ends to which support rollers are respectively mounted, the support rollers mounted to the ends of each horizontal sail bar being received in the C-shaped channel of the blade outer framework, whereby the horizontal sail bars slide between two side supports of the blade for ascending and descending without detachment; the rectangular blade has a lower edge and contact surface of the rotatable frame.
Type: Application
Filed: Feb 21, 2012
Publication Date: Aug 23, 2012
Inventor: Yuh-Bin Lin (Taipei City)
Application Number: 13/400,573
International Classification: F01D 5/14 (20060101);