US2081210A - Rotary propeller - Google Patents

Description

May 25, 1937. J u WILLIAMS. JR

ROTARY PROPELLER Filed J1me 22, 1936 INVENTOR. WWl/fidm: ,J'

- ATTORNEY.

Patented May 25, 1937 PATENT OFFICE 2,081,210 ROTARY PROPEI LER J U Williams, Jr., Los Angeles, Calif.

Application June 22, 1936, Serial No. 86,499

3 Claims.

This invention relates to an improved type of rotary propeller which may be used either in marine or aircraft propulsion.

Among the objects of the invention are, to reduce back pressure resulting from suction; to provide a more compact propeller by increasing the amount of propelling force obtainable within a given diametrical extent of propeller blade; and to stabilize and strengthen propellers without unduly increasing their weight.

A further object of the invention is that the propeller may be installed with the small end thereof directed either forward or rearward towards or away from its mounting respectively.

A still further object of the invention is to provide a rotatable propeller construction wherein two or more propeller blades of an elongated segmental character are so arranged that no part of one blade overlaps that of another.

Other objects, advantages and features of the invention may hereinafter appear.

Referring to the accompanying drawing, which illustrates what is at present deemed to be a preferred embodiment of the invention:

Fig. 1 is a combined sectional and perspective View showing the propeller together with the rear portion of the driving shaft to which it is secured, taken on line l--I of Fig. 2.

Fig. 2 is a rear elevation of the propeller shown in Fig. 1.

Fig. 3 is a sectional view of the propeller blade, taken on line 3-3 of Fig. 2, e

In the drawing the invention is shown embodied in a two blade propeller wherein the diametrically opposite blades 5 and 6 are supported upon a hub structure consisting of a frusto-conical outer shell I, an inner mounting portion 8 and a spider 9 which unites said shell I and mounting portion 8. Said hub structure has its mounting sleeve 8 splined to the driving shaft Ill. Between the arms of said spider, and to the rear thereof, are ample passages 9a: to relieve back pressure.

The small end of the outer hub shell I is directed towards the rear, and the spider 9 is united to only about the front half of said shell. Said shell increases uniformly in diameter from its rear to its front end. This leaves the rear half of the shell unobstructed and minimizes air or water obstruction around the bearing portion of the hub structure.

The blades 5 and 6 are of the same size and shape, and are each of a concave-convex form as viewed in front or in rear elevation. Along its inner, concave edge each blade is united to the exterior of the outer hub shell 1 either by being made integral therewith or in some other approved manner.

When two propeller blades are used they are positioned in such a manner that the concave inner edge portion of each blade includes within its 5 extent the butt end of the other blade and also spans the greater portion of the reduced end part ll of the driving shaft l0 upon which the hub is mounted.

Each of the propeller blades may be made of substantially uniform width and its thickness will vary in different parts as may be required to adapt it to meet the mechanical stresses encountered in its operation.

Each blade, beginning at the inner end thereof, has its inner concave edge spirally united to the exterior of the hub shell 1 for a sufficient distance to give such blade a secure footing. The inclination may be graduated as required to secure the best working effort. As viewed in Fig. 2 20 the propeller rotates counter-clockwise, and the fluid moves from right to left within the shell 1 as seen in Fig. 1.

The shell I has its front edge tapered at E5 and its rear edge tapered at It in order to secure a freer fluid flow within and around said shell. [1 designates the nut or screwbolt used for attaching the propeller structure to the shaft in.

In order to lessen still further obstruction to back flow through the hub construction, a plurality of auxiliary passages 20 may be provided through the shell 1 between the blades 5 and 6. Said passages are positioned with their intake ends directed towards the end of said shell which is of the greatest diameter, and said intake ends communicate with the shell I at points adjacent to the inner end of the inner mounting portion 8, Where the air passage through the hub is most restricted. Said passages are so inclined as to direct the fluid passing through them in such a manner as to create a cross-current effect upon the blades and thereby secure more propelling force.

I claim:

1. In a propeller, a hub construction including a frusto-conical open-ended shell having a main air passage extending longitudinally through it, there being auxiliary air passages leading through the wall of said shell and positioned with their intake ends toward the end of said shell which is greatest in diameter; and propelling blades mounted upon said shell, said auxiliary air passages all emerging from the hub between the inner ends of said blades and being inclined towards one side only with relation to the direction of rotation of the propeller, thereby creating cross currents of air which increase the propulsive force of said propelling blades.

2. In a propeller, a driving shaft, a propeller hub having an inner and an outer frusto-conical shell, said inner shell fitting over and being secured to an end portion of said shaft, both of said shells increasing in diameter from the rear to the front end of the propeller, there being spider arms uniting said shells and permitting an otherwise unobstructed space between them, said space diminishing in its cross sectional dimensions from the larger to the smaller end of said inner shell, there being auxiliary passages through saidouter shell which communicate with the interior thereof at substantially the place where the passage between said shells is of the least cross sectional dimension; and propeller blades mounted upon said outer shell.

3. A propeller hub construction comprising an inner sleeve attachable to a shaft, a frusto-conical shell spaced radially outward from said sleeve and a spider portion uniting said shell and inner portion, said spider portion having arms between which fluid may pass longitudinally through said shell and occupying the portion of larger diameter only of said frusto-conical shell.

J U WILLIAMS, JR.

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