US1017618A - Tangential-impulse water-wheel. - Google Patents

Description

S. L. BERRY. TANGENTIAL IMPULSE WATER WHEEL. APPLICATION FILED AUG. 15, 1910.

Patented Feb. 13, 1912.

UNITED STATES FATENT OFFICE.

SENECA L. BERRY, OF SUNNYVALE, CALIFORNIA.

TANGENTIAIi-IMPULSE WATER-WHEEL.

1,017,618. Original application filed November 16,

Specification of Letters Patent.

Patented Feb. 13, 1912.

1908, Serial No. 462,882. Divided and this application filed August 15, 1910. Serial No. 577,312.

To all whom it may concern:

Be it known that I, SENECA L. BERRY, a citizen of the United States, residing at Sunnyvale, in the county of Santa Clara and State of California, have invented new and useful Improvements in Tangential- Impulse Water-lVheels, of which the following is a specification.

My invention relates to tangential im pulse water-wheels.

The object of the invention is to obtain greater efiiciency, and much greater me chanical security, especially when using large volumes of water, than is now possi ble by the wheels ordinarily in use. This desired increased efficiency I obtain by so constructing the buckets and arranging them with respect to the water jet, that the splitter edges of the buckets will be normal to the direction of relative flow of the water entering the moving buckets whereby the line of the stream will not be deflected toward or away from the axis of the wheel on striking the buckets, but the reversal of the stream in the buckets will take place in a plane which passes through the axis of the stream and which is parallel to the axis of the wheel. The increased mechanical security is obtained by so forming the buckets and connecting them to the wheel, that each bucket will support the other circumferentially and prevent the disastrous consequences that so frequently follow from the usual practice of making individual buckets and imperfectly connecting them to the wheel.

The invention consists of the parts and the construction and combination of parts as hereinafter more fully described and claimed, having reference to the accompanying drawings, in which Figure 1 is an elevation of a part of a wheel showing the principle of the invention. Fig. 2 is a section on KK, Fig. 1. Fig. 3 is an elevation of a single bucket section.

In the form of the invention represented in Figs. 1 and 2, 2 represents the rim of a wheel of any suitable description to which the buckets are applied. My buckets are double buckets having cups or pockets 3 arranged in pairs on each side of a central dividing wedge or splitter 4, the sides of which splitter are continuous with the inner sides and bottoms of the cups 0r pockets.

Preferably there are a plurality of pairs of pockets or cups cast integral, each pair having a corresponding splitter, all being united to a pair of base flanges 5 which straddle the wheel rim 2; the bucket sections being bolted to the rim, as shown at 6. The bucket sections abut end to end circumferentially of the wheel so that all the buckets are mutually supported one against the other in opposition to the impact of the jet issuing from nozzle 7 The dividing line between two bucket sections or any group of integrally cast buckets is indicated in Figs. 1 and 3 by the irregular line LMG. The sections not only abut endwise, but this endwise support of one bucket on another, as seen, for instance, in Fig. 1, extends throughout the greater part of the radial depth of the buckets, so that the thrust of the water jet against any one bucket is resisted by all the other buckets behind it. Con= sequently only the strains due to centrifugal force are caused to fall directly on the bolts 6. The splitter faces of my buckets are all disposed in the plane of the center line of the jet issuing from nozzle 7 this center line being indicated at p. The splitter faces 4 divide the stream equally, one-half going to one side of the wheel, and the other half to the other, the divided stream being received into the pockets and discharged laterally therefrom.

The arrangement of the splitter 4: is important with regard to the efficiency of the wheel, as will be fully explained.

It will be understood that the mechanical feature of this invention is in securing the buckets to the wheel in the manner just described, so that each bucket supports the other; the hydraulic feature of the invention is in the formation of the splitter edge with respect to the water jet issuing from the nozzle 7, sothat the relative flow line (represented by E-A, Fig. 1,) is normal to the splitter edge. By employing a double bucket with a wedge-shaped splitter whose edge is at all times normal to the relative flow line of the jet when the bucket is passing through the jet, the stream will be received, reversed and discharged with a minimum deflection of its path from the line of the water column, thus allowing the wheel to run at the correct speed to utilize most fully the force of the jet. One of the serious faults of wheels of this type previously made, is that there is a great difference in the conditions governing the reception, reversal and discharge of the various parts of the stream taken care of by each bucket. Part of the water dischargesnear the point of entrance and part at a considerable distance along the stream line. It is proposed to correct this as far as it may be by the bucket construction shown, and to provide such a shape that a greater part of the water will follow the ideal stream path.

In order to clearly understand the construction involved, it is necessary to distinguish bet-ween the absolute and the relative direction and velocity of flow of the water. These terms and their applicability to water-wheels are explained in all c'om-' plete treatises 011 hydraulics, and may be briefly stated as follows :The absolute direction and. velocity of the water is its direction and velocity in relation to the earth, while the relative direction and velocity is its direction and velocity as they would appear when viewed from the moving bucket.

Referring to Fig. I, the line 7) represents the center line of the jet of water, which meets the circle 8-8 known as the outer circle drawn through the entering lips of the buckets, at A, and is tangent to the circle 9-9 known as the pitch circle. Let the line AC, of any length, represent the direction and velocity of a point on the bucket located on the pitch circle at the instant it reaches the tangent line 79, draw the line C-B at right angles to said line 79, cutting the line A-B which is tangent to the circle 88 at A, at the point B. Then it will be found, by well-known principles of geometry, that the ratio of the line AB to the line AC will be the same as the ratio of the radius of the outer circle 88 to the radius of the pitch circle 9-9, and the line BA will represent the direct-ion and velocity of the entering lip at the point A. As the absolute velocity of the parts of the bucket situated on the pitch circle is usually made one-half of the absolute velocity of the water, the line DA is made equal to twice CA and represents the absolute direction and velocity of the water. Completing the parallelogram by connecting the points B and D, drawing DE parallel to BA and AE parallel to BD, the line E-A will represent the direction and velocity of the water relative to the bucket moving under the conditions given. The line EA, therefore, expresses the relative flow of the water to the bucket, and the moving bucket receives water from the jet, the center line of which is the line 79, in the same way that it would were the bucket stationary and the jet center line placed on the line E A.

It is one important object of this invention to provide a bucket with a central splitter edge and pockets on each side, with the inner walls of the pockets converging wedgeshaped to the splitter edge and this splitter so disposed to the nozzle that the stream may reach the bottom of the buckets with the least possible deflection toward. or away from the axis of the wheel. To attain this desideratum the splitter edge is so laid out with respect to the proposed position of the nozzle 7 that this splitter edge will be constantly normal to the relative flow lines EA of the entering stream. ith the wheel and nozzle in the relative position shown in Fig. l the splitter edge AF curves inwardly toward the center of the wheel, but the pitch of this curve depends upon the position of the nozzle; that is whether the nozzle is nearer to or farther from the center of the wheel. Thus, for instance, as the nozzle approaches more nearly the center of the wheel than the position indicated in Fig. 1, the splitter edge gradually approaches a true circle, as in the case in the parent application, No. 462,882, of which this application is a division.

The edge of the splitter at represented by the line AF of Fig. 1 is normal at A to the line E A, which latter, as before stated, represents the relative flow line. If the conditions remain the same as at A this curve would be an involute on the circle at P, but as the splitter leaves the outside circle the relative direction of the stream changes and the radial lines of this curve are tangent to progressively increasing circles, the largest in this form of bucket being at Q. I therefore prefer to speak of the splitter edge as a modified involute inasmuch as the base circle increases in diameteiywhereas in the true involute it remains the same. The method of laying out this curve in actual practice is as follows :-The relative flow line E A Fig. 1, is drawn as described; a short line is drawn at A perpendicular to E A, the Wheel is then revolved until the end of this short line reaches the stream center line 79, at which intersection, a relative flow diagram similar to A B D E is drawn, taking into consideration the fact that this new point is on a circle of less radius, which changes slightly the direction of the line which corresponds to A B. From this second diagram a second short line per pendicular to the second relative flow line is drawn, and the wheel again revolved until the end of the second short line reaches the stream center line. This process is repeated until the series of short lines joined end to end reaches the back of the next bucket. A smooth curve is then drawn touching these lines, producing the curved line of the splitter edge. The method is an approximate one in which greater and greater accuracy may be attained by making the short lines shorter and shorter.

The reversing and discharging curves are shaped to perform their functions with a minimum of deflection of the water toward or away from the axis of the wheel and to prevent excessive spreading of the water, the final surfaces being arranged to discharge the water to clear the following bucket.

The shape of the buckets is generally immaterial, except that the splitter edge is made substantially wedge-shape, as shown in Fig. 2, with the base of the wedge running into, and in continuation of, the bottom of the pockets on each side of the splitter; the divergent splitter surfaces forming the inner walls of the pockets. The mechanical advantage gained is that buckets may be cast together, or abutted, if separate, in such a manner as to support each other throughout the greater part of the radial depth of the bucket, and prevent the serious damage which has resulted in some cases from separate buckets not so supported. In some cases these buckets would be cast as a part of the wheel-center, in others cast together in sections and bolted to the wheel-center, being parted, for example, along the line L-MG.

The principal hydraulic object of this construction is to provide such a splitter edge that the stream will be received with a minimum deflection of its path from the center line of the water column, toward or away from the axis of the wheel, thus al lowing the wheel to run at a correct speed to utilize more fully the force of the jet.

This case is a division of my original application, Serial Number 462,882, filed November 16, 1908.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is

1. The combination with a hydraulic nozzle, of an impulse water wheel having a circumferential series of double buckets, said buckets each having a splitter, said splitters in the plane of the center line of the nozzle, each splitter wedge-shaped in cross section, the edge of said splitter and said nozzle being constructed and arranged to cause said edge to be constantly normal to the relative flow line of the entering stream,

said splitter edge being in the form of a modified involute, substantially as described.

2. The combination with a hydraulic nozzle, of an impulse water wheel having a circumferential series of double buckets, said buckets each having a splitter, said splitters in the plane of the center line of the nozzle, each splitter wedge-shaped in cross section, the edge of said splitter and said nozzle being constructed and arranged to cause said edge to be constantly normal to the relative flow line of the entering stream, and said buckets being constructed and arranged to be mutually supported one by the other throughout the greater part of their radial depth, said splitter edge being in the form of a modified involute, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

SENECA L. BERRY.

lVitnesses ANNA BERRY, JOHN FAULDs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

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