US1267506A - Propeller device. - Google Patents

Description

W. S. BOWEN.

PROPELLER DEVICE.

APPLICATION FILED SEPT. 10. 1917.

Patented May 28,1918.

WILLIAM'SPENCER-BOWEN, OF NEW YORK, N. Y.

PROPELLER DEVICE.

Specification of Letters Patent.

Patented May 28, 1918.

Application filed September 10, 1917. Serial No. 190,556.

To all whom it may concern:

'Be it known that I, WIILIAM SPENCER BOWEN, a citizen of the United States, and

a resi'dent of the city, county, and State of New York, have invented certain new and useful Improvements in Propeller Devices,

of which the following is a specification.

My'invention relates to a propeller device consisting. of a propeller and a concentrator associated therewith. The invention is adapted for use in marine propulsion'or devicesfor testing propeller efliciency and in the drawings forming part hereof I have shown the invention adapted for ship propulsion.

f The object of the invention is to provide for the operation of a propeller in a fluid in such mannerthat the propeller may be operated 'at" high speeds without cavitation.

The device is adapted to increase the efficiency of the propeller'at various speeds and to make it"possible to operate it at higher speeds than has heretofore been considered practicable and sothat the efficiency at high speed will not be offset by cavitation. 'The propeller operates within the concentrator. The concentrator casing causes a constant reduction in area and within this casing there a double conical body supported in and spaced from the casing to provide an intermediate fiuid space which is of annularcross section. The casing and interior body cause reduction in area and the elimination of eddy. currents so that the propeller which is arranged in the casing operates always under uniform and favorable conditions.

Preferably there are rectifying vanes aft of r the propeller for rectifying the direction of the fluid as it leaves the propeller and these may take the form of the fixed vanes of the Thornycroft turbine propeller:

In the drawing forming part of this application, t

Figure 1 is a longitudinal sectional view taken through the middle of the'device,

Fig. 2 is an end elevation thereof,-looking at the left hand end of Fig. 1,

- Fig. 3 is an elevation of the stern of a boat to which theinvention is applied, and

Fig. 4.,is a plan view thereof,

The concentrator comprises ajifcasing 1 and the interior or core member 2. the latter being held in spaced relation to the casing by .lstruts 3, 4 extending between the inner boat.

' member 2 and the casing 1 and disposed at four forward struts 3 disposed 90 apart and similar rear struts 4'.

The forward end 5 of the casing is of large diameter and the exterior preferably tapers uniformly toward the rear end 6 which is of smaller diameter than the forward end; The exterior surface maybe modified more or less-but it'is preferable that its contour be tapering so thatifany fluid is displaced laterally beyond the width of the forward end of the casing it'will afterward react Jon the outer surface and thus reduce the losses in efiiciency due to any head resistance.

The interior surface 7 of the casing is generally tapering. It is preferably of extreme width at the forward end 5 and gradually decreasing toward the smaller'en'd. as far as the point 8 or nearly opposite the end of the inner member 2. From'the point 8 the angle of taper of the bore is, preferably lengthened at 9 and the extreme e'ndfIhave shown as ending in a short flare 10. I

The inner member 2 is doubleconical. The forward end. 11 which is shownas extending slightly forward of the casing,.is of small diameter and the niember-2 then gradually increases in diameter to the point 12 of maximum diameter which point is well within the casing. From the point 12 of maximum diameter. the member 2 gradually tapers at 13 to the smaller end 14 and this taper is such, in the preferred construction, as to make the exterior surface of the member 2 and the interior surface of the casing parallel. The propeller comprises the body'15- and the blades 16. The body 15 is preferably shaped so as to form substantially a continuation of the member 2. The blades may be of any desired shape or pitch, those shown herein being preferred. The propeller is mounted on the shaft 17 which extends forwardly through the center of the member 2 and there are bearings 18 in the member 2 for the shaft. Where the device is used for boat propulsion the shaft 17 extends forwardlyfrom the member 2 and through the hull 19 to the propelling engine within the arrangement the rudder will be positioned between the propelling devices. The

device may be arranged in various ways other than that shown herein.

When the device is used for propulsion the shaft 17 will be revolved at any. desired speed and one advantage of the present device is that it may be operated at much higher speed than the ordinary propeller having no concentrator and there will be no cavitation even at high speed. The revolving propeller will act on the water in the concentrator and at the point of high velocity, 2'. 6., at the restricted portion 8 of the concentrator. The fluid drawn into the larger end of the concentrator in large vol ume will pass through the space 21 around theinner member 2 and this space is of gradually decreasing area, so that the velocity of the fluid will increase as it passes toward the smaller end of the concentrator. The space 21 is annular in cross section and at the forward end of the concentrator'this space decreases in area both by reason of the convergence of the surfaces of the member 2 and casing and by reason of the taper of the casing. If the member 2 is made parallel with the inner wall of the casing from about the point 12 rearward, as in the preferred construction, then the annular cross sectional areas of the space will decrease uniformly toward the propeller. From the point 8 rearward the cross sectionalarea of the fluid space gradually decreases toward the discharge end, the taper of the inner surface of the casing being. on

a longer angle at 9 than the forward part 7 The shape of the fluid space shown herein is such that no matter how fast the propeller is operated there will be no cavitation and the highest velocity in the fluid will be attained at or behind the propeller.

There will be no cavitation or eddy currents caused by the centrifugal action of the propeller and the fluid will be delivered from the discharge end in a compact jet of high velocity.

There are no great losses from head resistance. When the water strikes the forward end 11 of. the member 2 the angle of deflection is such that the Water will not be driven beyond the lateral limits of the for- Ward end of the casing but will be deflected within the space 21. The reduction of area in the space 21 is gradual in order that the resistance will not be too great.

I prefer to provide rectifying vanes aft of the propeller to change the direction of the water after it leaves the propeller and to cause it to flow axially of the casing. For

this purpose I have provided a ring 22 within the casing, which rests against the shoulder 23. This ring carries the oppositely disposed fixed vanes 24 extending radially from 4 ward end, ,an inner member arranged in spaced relation to said casing and forming a longitudinal fluid space of annular cross section and gradually decreasing area, said inner member having a forward end of' gradually increasing dimensions followed by a portion of gradually decreasing dimensions, and a propeller in said casing arranged to revolve at or near the rear end of said inner member. Y i

2. A device of the class described including a concentrator comprising a casing havinga bore gradually decreasing from its forward end, an inner member arranged 'in spaced relation to said casing and forming a longitudinal fluid space of annular cross section and of gradually decreasing area, said inner member projecting beyond the forward end of the casing and having a forward end of gradually increasing dimensions followed by a portion of gradually decreasing dimensions, and apropeller in said casing arranged to revolve at or near the rear end of said inner member.

8. A device of the class described including a concentrator comprising a casing having a bore gradually decreasing from its forward end, a. stationary inner member arranged in spaced'relation to said casing and forming a longitudinal space of annular cross section. and of gradually decreasing area, said inner member being of double conical shape, a revoluble propeller body adjacent the rear end of said inner member and shaped to form a continuation of said inner member, and a blade carried by. said propeller body.

4. A device of the class described including a concentrator comprising a casing having a tapering exterior and having a bore the forward portionof which graduallydecreases from its forward end and the rearward portion gradually decreasing but on a longer angle to the decrease of said forward portion, an inner member of double conical shape spaced from the casing to provide a. fluid space of gradually decreasing area, the rear end of said inner member terminating at or near the juncture of said forward and rear bore portions and a propeller arranged ,near the rear end of said inner member.

5. A device of the class described includa propeller arranged in said casing and to ing a concentrator comprising a casing havthe rear of said inner member and rectifying ing a bore gradually decreasing from its forvanes arranged in said casing to the rear 1 Ward end, an inner member having conical of the propeller and adapted to rectify the 5 forward and rear portions and spaced from flow of fluid for the purpose set forth. the casing to provide a fluid space of annular Signed this 25th day of August", 1917. cross section and gradually decreasing area, lVM. SPENCER BOWEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latents, Washington, D. C.

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