Patent Application
20130136613
The present invention relates to propeller/impeller blade design and, more particularly, to a propeller/impeller blade design that keeps its shape under load.
Blades are commonly used in various devices, such as propellers, wind generators, turbines, pumps, blowers, fans and other like apparatus. Whether used as a propeller or an impeller, an aircraft propeller, boat propeller or a fan, the blades themselves are essentially the same.
In general, such blades are twisted and angled to either propel a medium such as a liquid, gas or slurry past the blades or to cause a medium to impinge upon the blades to cause rotation of the blades about a shaft. For example, a boat propeller generally consists of two or more blades attached to a hub or shaft with the blades being twisted and raked backwards. The blades are symmetrically arranged around the circumference of the hub. The overall diameter, the amount of rake and the pitch of the blades all play a part in the performance of a propeller. Airplane propellers and fan blades are not unlike boat propellers, the difference being that air is moved rather than water.
Although somewhat useful for their intended purpose, conventional blades include certain inherent limitations and, therefore, have not proven to be entirely satisfactory. Specifically, the rake and pitch which may be achieved using conventional blades are limited because the transverse flow components of the conventional blades are diminished at the inner and outer ends of the blades, thereby wasting energy and losing efficiency. Furthermore, under load, the conventional blades are often unstable and must be constructed of rigid materials to maintain their stability. For instance, air craft propeller blades contort under load, bowing forward in relation to the direction of travel. Inefficient operation. Also, being restricted to rigid materials increases the cost of devices utilizing these conventional blades and limits the design alternatives, both functional and aesthetic, which can be achieved if other more flexible materials were used.
Some devices have been developed which differ from the conventional blade configurations. Most merely change the blade orientation with respect to the shaft so that the longitudinal axis of the blades are parallel to the shaft. Typically, these devices are specifically designed for use with wind turbines or mixers or agitators in a vertical orientation.
As can be seen, there is a need for an improved impeller/propeller blade design.
In one aspect of the present invention, a blade apparatus comprises at least one blade strip; blade tips of adjacent ones of at least one blade strip connected together; and a central region of each of at least one blade strip connected to a shaft.
In another aspect of the present invention, a blade apparatus comprises at least a first and second blade strip; blade tips of adjacent ones of the first and second blade strips connected together; a central region of each of the first and second blade strips connected to a shaft; and a hub interconnecting the central region of each of the first and second blade strips with the shaft.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Broadly, an embodiment of the present invention provides a medium mover/reactionary surface that can be used as a propeller, impeller, wind generator blade, mixer and the like. The blade design has a shape that pulls against itself under load to maintain its intended shape. The blade design includes one or more generally flat or contoured strip-like sections. These strip-like sections can be attached at their centers to a hub and at the tips to create rake and pitch.
Referring now to
The blade strips 12 can be attached at their centers to a shaft 20. Typically, a hub 22 can interconnect the blade strips 12 to the shaft 20. In some embodiments, the hub 22 can include a hub shaft to connect the blade strips 12 to the hub 22. In the embodiment shown in
Referring to
As shown in
Referring now to
The blade strips 12 can be made from various materials, such as wood, metal, plastic, composite, or the like. The blade strips 12 can be made from various manufacturing processes, including molded and machined.
The blade strips 12 can react to a medium, causing the shaft 20 to turn, or may be turned by turning the shaft 20 to move a medium. The blade design of the present invention can be used for a propeller, impeller, wind turbine, mixer and the like.
While the above drawings show the shaft disposed generally parallel or perpendicular to the axis of the blade strips, the shaft can be disposed at any angle relative to the orientation of blade strips.
It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
This application claims the benefit of priority of U.S. provisional application No. 61/563,704, filed Nov. 25, 2011, the contents of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61563704 | Nov 2011 | US |
