US1749087A - Ship propulsion - Google Patents

Description

March 4,-1930. P. F. RILEY SHIP PROPULSION Filed Oct. 25, 1927 f Pa ent d Mar; 4, 1930 7 PATE I oFFicE PETERJF, RILEY, on CHICAGO, ILLINOIS SHIP PROPULSION Application filed. October 25, 1927. Serial No. 228,565.

r 1 This invention relates in general to ships and. boats and, more particularly, to an im- V 1 proved method ofandapparatus for propulz siOntherleof; v I I .jifltis well known to those skilled in ship 7 building and "in naval constructing andthe likethat in the ordinary screw-propeller as customarily employed in the power plant'of a'fmechanically propelled, vessel such as, a

' Q steamship, the maximum rate. of speed at which the propellers may be driven to Oht am the maximumefficiencyand economy in operation and also; maximum speed ofthe vesselthrough the water'are all limited by the l 715 rate atwhichthe water willflow to thepro- 'pellers and that the forces normally tending to move water to the propellers are solely the forces of gravity and" ofthe expansive properties of air. That is, in a steam vessel unf der way with the conventional form of stern propelleifl if this propeller, in response to the i I powerfin' excess ofthat normally employed to drive the vessel at its maximum rateof speed through-the water,.is caused to be roz t'ated at ahigher rate of speed, the speed of the vessel does not only not increase but may even decrease, forrtlie reason that cavitation begins to take place, that is. owing to the f i rapid rate at which the blades be the propeller Q ment' of the water, which in reality results in pass throughtheir revolutions their displaceforward movement, of the: vessel, is such thfat'water on the forward faces of the blades,

I, 55.11% is, the faces toward the bow of the v gravity and'theezqjansive properties of air,

which is supplied thereto'by the force of does not reach theblades intimeto be ofany valuepand the result is that behind each blade in its path of; rotation there is a vacuum which not only tends to eliminate the forward movement of thevessel but tends to carry any wateriwhich is behind the blades in their of-rotation toward the nextpreceding blade. This condition is further caused to prevail byjthe forward movement of the vessel through the waterand the tendency for the f w'ater ahead'of the propellers tofollow the curved linesofthe vessel at its stern. The 5 conditions mentioned'aboveare notmaterially remedied by placing the propellers at the forward part of the vessel.

eliminate cavitation at the propellers and to 1ncrease the rate of speed at which the propellers may be efficiently and economically operated to employ all, or nearly all, of the power available in the power plant of the vessel; the provision of an improved method of and means for supplying water to the propellers of a steam vessel or the like whereby to cause the water to flow to the propellers under a force in addition, to that of the forces of gravity and the expansive properties of air; theprovision of an improved propelling method and means for vessels which includes placing the propellers'at theforward part of the vessel and supplying water theretovin excess of that normally required by the propellers to propel the vessel; theprovision in a power plant for mechanically pro pelled boats and ships of an improved propelling means therefor in which the efficiency of the power plant and the action of the propellers on the water are enhanced, whereby to permit of greater rate of revolution of the propellers than that heretofore possible in steamships and other mechanically propelled vessels known to me; and. the provision of an improved propelling means for mechanically propelled vessels that which will permit of operation of the propellers without cavitation and also permit of steering the vessel inde pendently of or in conjunction with the usual steering'mea-ns such as a rudder.

The foregoing and such other objects and advantages as may appear and be pointed 7 exhaust'or discharge passageways 34 and 35,

the main engines.

I Figure 3 is a fragmentary elevational view of the forward part of the vessel;

And Figure a is an enlarged composite.

drawing, 1 have illustrated a steam 'vessel 1 having .a hull 10. provided with the usual double bottoms 11, the stem being indicated at 12 and the stern at 13.

The vessel may be equipped at the stern with the conventional rudder 14, it being observed from Figure 1, that the lines of the vessel are modified from the usual standard construction by increasing the bluntness of the bowas indicated at 15 and 16 and tapering the sides toward thestern as indicated at lfland118. i 9 The improved propelling means vof my in vention includes water inlets indicated generally at 919, 19, and having each a general conedike shape in'v'the nature ofa-funnel with the larger open end thereof adjacent the stem l2to permit of, the entrance of sea water. so as to not weaken the stem of the vessel, this stem. may pass downwardly in the usual manner, the intakes 19 being arranged oneither sideofsaidstem, without the latter materially interfering with the'flow of water into the intake. i v r At the after-portions of the intakes 19,

preferably immediately adjacent the apex 20-thereof,iin each instance, I have arranged propellers21 and 22' Obviously, one intake and one propeller may be employed if desired, but'l have preferred to disclose the employment of twin screw propellers, one of each arranged on either side ofthe fore'a-nd aft line of the vessel and receiving water fromthe funnel-like intakes 19. Thempro- .pellers21 and 22, which are preferably' of theiconstruction to he hereinafter described, are fixedly mounted upon and have rotation with propeller shafts 2:2 and 23. The shafts E22 and-'23 are mounted attheir vforwar-d portions in bearingsQ l; and25' carried by suitable spider frames26 and 27 located in the intakes 19 or in passageways28 and 29, forming short extensions of the water intake and;

in which passageways one each of the propellers 21 and 22 is mounted forrotation. The passageways 28 and 29 extend to and communicate with-water expansion chambers 30 and31, these chambers/having downward extensions 32 and 33 which pass water into:

which eXtend toward the afterpart of the-vessel. The after ends of the propeller shafts 22 and 23 extend through the walls of'the chambers-'30 and 31-andintozthe vessel and are connected inany preferred manner with "In orderito prevent damage to the-exhaust or discharge conduits, these conduits maybe housed within the double bottoms l1 and vessel. 7 a I find it expedient to provide two or more may-discharge into the sea at points adjacent the stern of the vessel or justforward of the stern. This arrangement of the discharge conduits in the double bottoms willprevent damage in the event of grounding of the of the exhaust passageways '34 and 35 on either side of the fore and aft line of the vessel, extending parallel tothe fore and aft line and in spaced relationship so as to r be capable of taking careof the water introduced at the intakes and' propelled through these-passageways by the forward movement ofthe'vesseh These passageways being open at theirafterends as indicated at-36 and 37, WlllSQTYC QLQOLIISQ,@S ;1Iltt1l g whenbackingthe vessel.

For the purpose of aiding i1r-the.stee ni; g

of the vessel, 1 provide bye-passes 38 and 39-5 and 40 and elcontroll-edby valvesAQAQland being arranged in the discharge conduits 3,4;

and 35 for controlling the discharge of sea water-"from the propellers; The valves .42, 43, 44,45, 46 and ,tlmay ahe, controlled synchronously frointhe bridge of the vesself for the purpose ofsteeringoraiding in the steep ing,;that is, {it Will .beiob QuS y iclosinewibs valves 4e, e5, ;46 and a7, an d,. opening the starboard or port valves .42 or (t3, :the discharge of the water in a direction alonggthfe' line of the :by-passes138and :39 will result an a tendency'for the vessel-to belturned to starhoard.orport,as {the "case may he. The supplyofwater for-this purposemay he aided byproviding the connecting by-passes AC8 v and 49. 'Thesexhy-passes may bearrange'd at any convenient poi t t connect 09m? plemental conduits )of :the 34, d jcth pair 35; r a,

ness in Figure .3) may be provided atfthe intake ends ofthe funnels 19 for preventing the entrance of :heavy ,objects-iwhich may intakes a ndrpr'opellers, a

-The disposition ,of the intake 19: in vessel may be, of course, yar ed in accord-'- ance with the design ofthe ,hull andjthe Suitable gratings e48 for clear-f I 1* be encountered and-wouldtendto injurethe 7' 3' form of the intake is" as readily adaptable having a straightlstern as shown.

to a vessel having a clipperbow as .to one The method involved in the present iii".-

vention will'be :found to residein the operation of a propellerwhich supply'of wat r 1s had under pressure to the propellerin 1 xcess of that no rmall Y supplied by ,gray ity and air iunderpressure, 'Thisincludes cofn stricting the" stream of water-tofthe. path directed against the propeller so tliat cavita- 1 tion cannot'occur. Thi's is best accom-plishedf,

plying Water at a greaterrateof speed and pressure than would be supplied were gravity be observed that owing to the forward motion of the vessel and the constricted inlet,

a given' volume 'of water entering at the mouth of the intake and. moving a given distance in a certain length of time is accelerated and will thereby be introduced to the propellers faster than it ordinarily would be under the forceof gravity and the.

1 action of the expansive properties of air.

Thus, the propellers may operate at a greater rate of speed than normal for the same diam- "eter of propeller and same power plant as applied in the conventional manner at the sternof a vessel and without any means for I eliminating cavltatlonw There Wlll be no "tion, for thereason'that the. rate of flow of Lwater tothe propeller is accelerated by the tendency for cavitationin applicants invenconstricted opening and; that the ratio of ,speed of vessel through thewater and rota- 'tion of the propeller blades with respect to the rate of flow of the water into the constrictedpassageway will always be such that the seawater will -flow to the propeller at I y a greaterrate than that at which thewater has enters at the intake. This will hold good regardless of the speed at which the vessel is propelled'under its own power.

' It will be observed that the normal forces tending to move water toward the propellers are the-forces of gravity which are, roughly,

15 pounds of air pressure to the'square inch 2 and pressure of about 3 pounds to the square inch gravitation effect: of the water, that 1s, weightv of the water, making a total of subing to move the 'waternormally toward the stantially 18 pounds to the square inch, tendpropellerblades. When, in addition to this,

. the same volume of water passing into the I intake in a given length of time is caused to pass through a smaller. spacein the" same length of time it must move more rapidly andftherefore pressure of 18 pounds to the j square inch is exerted, in addition to the ef- "fect, of such constriction. The effect which this will have on the propellersdepends on the size of the intake at its mouth with respect to the diameter of the, propellers and I the constricted passageways. I have found that with an intake of asubstantially 9-foot diameteran angle 'ofapproximately 30 of "the walls of the intake with respect to the vantageous where a 6-foot propeller is emfore and aft line of the ship should be adapproved manner.

It will be observed that'when there is an excess of water flowing to, the propeller which cannotfget past the propeller, this water will causea backing up at the, entrance to theintake and creates. wave ahead of the vessel, but" as this is normal in the operation pf' allvessels it will have no effect on the efficiency of' the device and will have little effect in retarding the progress of the vessel through the water. f

In Figure l, I have illustrated a form of propelled which I prefer to employyfthe propeller being in effect an interrupted screw thread or a plurality of screw threads interrupted so that a four-blade propelled be provided. These blades are indicated at 51, 51 and being mounted on the shaft 22 in any The blades, it will be observed, are, in effect, interrupted screw threads lying in substantially the same transverse plane and are all substantially the same width throughout their length. Obviously, the diameter of the propeller is such that it substantially snugly rotates in the chamber formed at the apex 20 of the intake so thatlittle or no water can escape between the outer edges of the blades and the interior surface of the wall of the chamber referred to. i

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. In a propulsion means for ships, in combination with the hull of the vessel, a funnel shaped intake at the forward part of the vessel below the water line, a propeller arranged axially of said intake at substantially the apex thereof, and substantially filling said intake at said apex and a water exhaust conduit extending aft from said propeller having an enlarged water expansionchamber therein, and means in said conduit for regulating the rate of flow of water therethrough.

2. In a propulsion means for ships, a water inlet having a cone-like contour, a plurality of propellers arranged complementally on either side of the longitudinal axis of said cone-like inlet 'atapproximately the narrowest portion thereof, an enlarged water expansion chamber, a plurality of discharge conduits extending from said chamber and means for controlling separately the flow of water therethrough.

. 3. In a ship propulsion means, the combination with the hull of the vessel having a stem, of a water intake having converging cone-like portion extending aft from said stem, and having a continuation of substantially uniform diameter, a propeller mounted for rotation in such portion and adjacent to the narrowest portion of said intake, and a water expansion chamber abaft said propeller;

4. Ina ship propulsion means, the com-

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