US 1103053 A
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FLUID PUMP 0R MQEGR.
APPLloATmN FILED JAN, 9. 1911.
Patented July 14,1914,
` FLUID rumana Moron.
To all whom t may concern eration of the vteeth thereof.
' tally disposed inlet-1:
Be it known that I, KARL Kram, a citi.- zen of the. United States, Aresiding at Cincinnati, in the county" of Hamilton and .State of Ohio, have invented a 'new and '-'useful ImprovementY in Fluid Pumps or Motors, ofwhich the following is a specification.
My invention relates tary pumps or motors, provide a device of this to double-piston roand the Objectis to character of simple construction that will be highly efficient,
and steady and quiet in its o ratlon.
My invention consists in t e parts and details of construction and arrangement of parts,-as will be hereinafter more fully described and claimed.y
In the drawings: 'Figure 1c is a vertical section taken through the middle of apumplongitudinally of .the inlet andout-let. Fig.
2 is a vertical cross section taken throughv the middle of the pumplongitudinally of theshafts. Fig. Sis a detailed side elevat-ion ofi-the rotors or pistons of the pump.
Fig.- 4- isa detailedperspective-View of one of the ends of the casing, better illustrating its inside formation. Fig. 5 is a diagrammatic view to illustrate vthe operation of Vthe teeth of the rotors or pistons. Fig. 6 is a detailed perspective view'of 4a part of one of thev pistons to further' illustrate theop- The-casing 1 of the-pump'hasa4 horizonand afsimilarl'ydis posed outlet 1 'on'ther'opposit'e side'from lthe inlet, andthe ends vlian'd 1b, of the cas'-v ing support the, rotors or pistons 2 and 2a l with their centers tactis made -Outlbfa-'S will hereinafter be. 'moreifllly set forth.' Except Awhere' theyv 'enter- A. the inlet and outlet passages,
theinner pistonsrunning vinthe' directions lndicated '55 b the arrows, the liquid vl'enteringat the in.
or axes equidistant above and below, respectively, .the center line of the inlet: and outlet. yThese -rotors'or p15-P tons 2 and .2 have vhelicalteeth` 2. and 2a" which mesh together-between theinlety 1 and the outlet-1 and the teeth .are so ar-y ranged,vand -of such .proportion and osch numberthat a substantially fluid-tight con'` hereby between said inlet and.
thel'pistons- 2 and@ are inclose'd by the walls ofthe. casing 1 ,so that the teeth 2- andfgl"Larefcloseiy adjacent for e walls, and lthe concave sides: of y,th
let 1f will .be carried around inthe spaces between the teethto the outlet 1, where it Specification of Letters Patent. ,Application filed January 9, 1911. Serial No. 601,599.
is forced from" between `said -spaces by the Patented July 14,1914. 1 I
intermeshing of /tlieteeth 2 and 2a of the l pistons. A by-pass 3 leads from' the. outlet 1. in-
. teriorly of the wallgofthe casing 1, `over the upper pistonv 2 anddown to the inlet 1, and
is closed by the valve 3 located verticallyI above the pistons, which is unseated upward, and normally held'y down by a, spring 3* adJusted by 4a screw v39;' thusthis valve 3a may be adjustedv to maintain: any y desired pressure at' the )outlet 1, and tol allow the excessffluid to,;pass back'to the inlet through the luy-pass'l.'
The two rotors yorjgstonsQ and 2a preferably have their teethk designed theoreti# cally correct sothat'they constitute. a pair of intermeshin gears, and the upper -piston or gear 2 is a apted to drive the lower piston or rear 2". Accordingly', itis possible to avoid .the use ofl an objectionable number of stuiing boxes or glands around the shzuftsV of the pistons vor gears. .As ill'u`strated,`it is`-l I necessary to have a glandaround the driving 2 only,.the 'stud 2c which supports said gear 2 being rigidly upper gear 2 has a central bore, turn' loosely lon', and theremaining part `of sald bore receives -the inner end of ing shaft 2", which has a-key 21.rigidl .securing it to the gear. 2. The part o the shaft'2b of 'the upper piston or gear mounted inthe casing, as 1s 'y also the shaft/2'd of the lower gear 2a. 'The into .part ofV whic extends' the 'studv 2c `for said gear to driving shaft 12?" 'outside of the'casing may be provided with an driving the pump, w necessary'vgto herein" The lower ,crear 2" t`urns loosely yon'th'e shaftf2df I' *il suitable means *for* 'lift 'icli'it vis not deemed illustrate or describe."
1 liis- Waite aangaande of thejcasing have extensions 2', .to receive a v d surround the ends of the'shaftl", laiid'f-th endl? has 4 similar extension 2?. whichrece'ives and s urroundsltheend'of'the'f'stud 2F. g'l`hebear1ng"' 2 for 'the'shaft 2h basa". 'stuiilng box or gland ij 1- 2? around fthe sh 'ft -arjic'ifbetweenthis gland andtheige'ar 2 there isan 'annular -recess 2" i 5 -10 inunieate's,controlled`by aplugQf. Leading 'frolnv the, annular recess 52"1 interiorly pf v lubricant and act as a'reservoir .therefor infside the gear 2. i Thestud l2c has a spiral.`
groove 2g on its convex surface that communicates between the space 2g and an interior passage 2g. inside the stud 2c that leads from the end of said spiral groove 25, inside the gear 2, toI the end of the stud 2 inside the extension 2', which is provided with an outlet controlled by a plug 2h. The shaft 2d has an linterior passage 2d leading from one end to the inside of the gear 2, and there communicates with one end of the spiral groove 2k, the other end of which communicates with another interiorpassage 21, in the shaft l2, leading to the other end of the shaft inside of the other extension 2d', one of said extensions being provided with a grease cup 2m controlled by a plug 2u, and the other extension having an outlet controlled bythe plug 2. It will. therefore be seen that the lubricant can be supplied to.
the gears 2 and 2a by opening the plugs 2f;
and 2m', respectively, w ile that which has been used may be allowed to escape by opening' the plugs 2h and 2, respectively. Vl these plugs are closed and the stuf'ing box 2e is roperly packed, no lubricant can escape rom the pump to the outside. For confining the lubricant around the shafts, the gears are provided on their ends with annular acking rings or gaskets 2P, which bear against the innersides of the ends l and lb of the casing, so that the lubricant can' not mingle with the fluid being moved by the pump.
lt will be noted that the valve 3 in the bypass 3 has a conical seat 3a', but that the openin below this seat has parallel lsides while t e valve 3a is shaped accordingly, so that it may have considerable vertical movement before the valve will be permitted to vibrate, as it would if only held in alinement by its spring 3b. Also, this valve 3a has an upper cylindrical extension 3a that fits closely in a cylinder 3W that forms part of the valve casing; with the plug 3', which carries thescrew 3", screwed into the upper end of this cylinder 38', the cylindrical extension 3a of the valve 3 confines a certain amount of air inside the cylinder 3a, so that the arrangement performs the function of a'dash-pot with a steadying effect on the operation of the pump.
4ingl The pressure gage may be applied to the pump in the threaded opening 3 leading to the by ass 3, and the lower part of the casas an opening 1. in which a drain cock Imay be applied to the pump. v
' The teeth -2 and 2a ofthe pistons or gears 2 and 2 respectively, are, onY each gear, inversely directed from the ends of the gear toward the middle thereof, meeting in the mid-l dle at an angle sothat they are of what is known as herring bone formation, and of course, as is necessary in helical gears, the,
the teeth be theoretically correct; it is necessary that there always be teeth of the respective' gears making continuous contact from end to end of the gears, so as to maintain the substantially fluid-restricting means between the inlet and outlet, the absence of which so seriously lowers the eiliciency. W'ith the use of the helical gear teeth, this continuous line of contact from end to end o the gear is of shorter duration than with simple spur gears, and it is necessary to provide the teeth 'in such a manner that before any two teeth begin to recede from each other near one end of the gear, and thus destroy the continuous line ofV contact, the next two teeth will have .completed their continuous line of contact from end to end of the gear. A
- The above will be understood upon inspection of Figs. 5 and 6 of the drawing.
In 5 the tooth A of one gear and` the tooth A of the other gear'are maling contact at a. Now, let it be understood that each half-length of a tooth, from the angle in the middle of the herring-bone gear to either end, is to be considered as a complete tooth for the purpose of the following explanation. Also let it be assumed, for instance, that. as illustrated in Fig. 3, the pitch of the helical teeth is such that a tooth advances a distance equal to the circular pitch of the gear. rlhus, the other end o1 the tooth A will be coincident with this end of the tooth B; and the point of contact at that other end will be coincident with the point of contact seen at b between the teeth B and B in Fig..5, which, of course, shows this end only. The line of contact made by the tooth A alongthe side ofthe tooth A will be projected along the line as seen in Figs. 5 and 6.
The same relation exists between the teeth B and B, which, as seen in Fig. 5, make contact at b at their near ends; at their in their advanced'regions, coincident with the brea the continuity of theirline of contact ,int c, the teeth B and Bf are about to lFrom the above itwill' be understood that, u
c', but the teeth'A and A are completing their continuous line of contact y at a, where the teeth end at the sides of the gears, as above explained. Thus, the' teeth A and A are complementary tact.
Ateeth is afforded in tion of the fluid from the spaces between the lonly being necessary t in the middle of the gear,
.Consideration of the above circumstances w1ll make it apparent that such operatic-n of `the teeth as above described is dependent upon the relation of the length of the gear to the helical pitch and the circular pitch of the teeth. Forexample, with such a rotor or piston of length approximating its diameter, it is necessary to have from 20 to 30 teeth thereon, each advancing around the piston a distance about equal to the circular pitch of the teeth. By thus assuring a constant closed joint between the intermeshing teeth, the helical teeth aremade just as efficient as any other form of impeller, with ref' spect to leakage of the pump, andv the full advantage attained by the use of lhelical theoperation of the pump. This advantage consists in the ejecteeth, by the intermeshing of the teeth, in direction toward the end of the gear. By providingy the teeth of each gear pitched in both directions and meet-ing at yan angle in the middle of the gear, or of herring bone formations the fluid thus passes tofboth ends of the gears and escapes i to the outlet 1` through the recesses 2f in the inner sides of the ends la and l" ofthe casing. 1t will of course be understood that. some of the Huid will be displaced over the tops of the teeth when they intermesh, but the endwise means of escape afforded for the Huid greatly increases the smoothness of operation of the pump, and practically eliminates all lvibration, which has been a very objectionable feature in pumps of this character heretofore produced, in pumping liquids.
From the foregoing descri tion it will be 'understood that the continuity lof fluid reous contact between the lrespect-ive teeth to the angle ofhelical 'advance of the teeth; and this advantage is not dependent upon coincidence of overlap ing tooth-ends, vit
liat the helical ad- Vance be less than the angle of rotation during which the respective gears have the con 'nuous contact-.I advantage is attained in connection withthis continuity ofV iuid restricting contact4 by making the overlapping tooth-ends coincii dent as shown. By thus havlng 'the end of a tooth at one end of the gear, or at the angle coincidentwith the beginning of a following tooth, at the other end, the full advantageof the helical to the teeth- B and B in maintaining constant huid-restricting con-f any L tion in these regions 'teeth where they However, an importantl gear inproducing steady delivery of fluid without pulsation is attained; for without such coincidence the gear has character of a .plain spur gear with teeth running parallel to the axis. lVith lSuch a plain spur gear, `or with a helical or herring-bone gear without the coincidence of tooth-ends above alluded to, there is a variation of condition in the region where the teeth emerge from the inclosing concave casing walls. With the. plain spurgear, at one instant a complete tooth-top will bel presented, and at the next inst-ant a complete interdental space will be kind lof helical gear not having the tooth-ends coincident, -t-hese tops and spaces will be varyingly presented with less degree of completeness across the gear, but yet with a large degree of irregularity of condition in these regions. With the tooth-ends coincident, there will beno instant when there is a complete tooth-top presented or when there is a complete interdental space presented, while,`in addition, the proportion of top and space -presented will always be the same, and the conditions in this region will be uniform; so that by this means not only is the advantage gear, but this advantage of the helical or herring-bone gear is completely attained.
ASince freely open interdental space in this region permits free escape of fluid, and a tooth-top in this region prevents escape', it will be seen that acohstant proportion o these two will result inl elimination of alternate increase and decrease, or pulsation, of
delivered fiuid.. Such uniformity of condiwhere the fluid escapesv from between theteeth will, however, be of .little significance without the continuity of iiuid restricting contact between Ethe interm'eshing teeth,because leakage back between the teeth, in addition to being a source of waste, is also a cause .of irregularity of delivery of fluid and also causes pulsations wherepermitted. 'lt is, therefore, by the more of the presented; and with attained over the plain spur combination of these provisions that my obvject is attained most completely. U While the above provisions eliminate pul-- sation in the deliverycf a pumpfthe opera.- tion of a. motor constructed as above described will be steadier, on account of, the uniform rate of inflow of fluid between the enter behind the concave walls of the casing, and because of the elimi. nation of leakage between the teeth of the two gears where they intermesh.
. Having fully described my 1nvention,what` 1 claim as new and desire to secure by Letters Patent is? 1;V In a pump or Iimotor pistons consistingl of intermeshed helical gears, respective teeth of which have continuous contact from end to end during rotation thereof through a vancing helically thereon, vrespective teeth of which have continuous contact from end to end of the helical advance of the respective teeth during rotation of each gear through a certain angle, and said helical advance of each tooth being through an angle not eX- ceeding said angle of rotation. 3. In a pump or motor having an inlet and an outlet, pistons consisting ot' intermeshed gears, each with .teeth advancing helicallyv thereon, respect-ive teeth of which have continuous contact from end to end of the helical advance of the respective teethy during rotation of each gear through a certain angle and said helical advance of 4each tooth beirfig throughv an angle not exceeding said angle of rotation, the outlet mea-ns having communication -at the ends of the gears with the spaces between the teeth Where lthe gears mesh.
4t. ln a pump or motor pistons consisting vof intermeshed gears, each having inversely arranged helical teeth forming angles mid- Way of the length of the gear, the respective teeth of said gears having continuous contact from end to end during revolution thereof through a certain angle, and the angle of advance of each tooth, from the end of the gear to its angle midvvayof the length of the gear, being not in excess of the aforementioned angle.
5. in a pump or motor, pistons consisting of intern'leshed gears, each with teeth advancing helically thereon inversely and forming angles intermediate of the length of the1 gear, respective teethY of the gears having continuous contact freni end to end of' the helical advance of, the respective teeth during rotation of each gear through a certain angle, and said helical advance of each tooth being through an angle ynot eX- ceeding said angle of rotation. f 6. ln a pump or motor having a casing with an inlet and an outlet, pistons therein consisting of intermeshed gears, each With teeth advancing helicallythereon inversely and forming angles intermediate of the length of the gear, .the respective teeth of i said gears havlng continuous contact from end to end of the helical advance of the respective teeth during rotation of each gear through a certain angle, and saidhelical advance of each tooth being through an angle not exceeding said angle of rotation, and the casing adjacent to the' ends of the gears having spaces :communicating With the spaces 7. ln a pump or `motor, pistons consisting of intermeshed gears, each With teeth advancing helically thereon, respective teeth of which have continuous contact from end to end of the helical advance of the respective teeth during rotation of each gear througha certain angle, lsaid helical advance ofeach between the teeth Where-the gears mesh, and Iwith said outlet.
tooth being through an angle not exceeding said angle of rotation, and each of the teeth being,.at'the end of its helical advance, coin- .cident with the beginning of helical advance of another tooth on therespective gear.
8.V ln a pump or motor, pistons consisting of intermeshed gears, each with teeth fadvancing helically thereon inversely and forming angles intermediate of the length of the gear, respective teeth ot uthe gears having continuousicontact fromend to end ofthe helicaladvance of the respective teeth during rotation of each gear through a certain angle, said helical advance of each tooth `being through an anglenot exceeding said angle of rotation, and each tooth, Where its helical advance ends at the angle intermediate of the length ot' the gear, being coincident with the beginning of the helical advance of other inversely helically advancing teeth on the gear.v l
ln testimony whereof l have signed my name to this specification in the presence of two subscribing Witnesses, this 5th day of January, 1911. 1
' Kann Kieran.
It is hereby certified that in Letterslatent No. 1,103,053, granted July 14, 191.4,
upon the application of Karl Kiefer, Fluid Pumps or Motors," errors` appear in the printed specitieation requiring co1'- reotion as follows: Page 9i, line 115, for the reference-letter au read y; same page,
line 125, for the reference-letter y read and that,l the eaifi Letters Patent should be read with these corrections therein that the same may conform to the record of the ease in the Patent Oiice. i
Signed. and sealed thisQOth day of October, A. D., 1914.
J. T. NEWTON [SEAL] i u Acting Commissioner of Patents.
of Cincinnati, Ohio, for an improvement in