US2408716A - Pump construction - Google Patents

Description

E. s. WITCHGER PUMP CONSTRUCTION Filed Dec. 10, 1942 Oct. 1, 1946.

INVENTOR. EUGENE 5. MTG/6 R AITaZA/E Y Patented Oct. 1, 1946 PUMP CONSTRUCTION Eugene S. Witchger, Grosse Pointe, Mich, as-

' .signor to Eaton Manufacturing Company,

Cleveland, Ohio, a corporation of Ohio Application December 10, 1942, Serial No. 468,500

, Claims.

- Thi invention relates to pumps in general, and, more particularly, concerns-a pump construction mountable directly upon an internal combustion engine'block without a separate pump body and in communication with ports in the engine block.

It has been suggested heretofore to incorporate engine pump intake and discharge openings in the engine block with a view to reduction in the total cost of the engine, and advancement of the art in general, Such suggestions insofar as applicant is aware, have been limited to intake and discharge ports of a size and shape normally able to'accommodate the timing for which the pump was'designed, and, also any slight coring inaccuracies that might occur in the block casting operation, and which would otherwise render the block worthless for a pump construction, such as the present, which is critical in its porting arrangecient working fluid for a complete pumping cycle, by providing secondary distributingor balancing ports'in a pump cover element that are disposed outwardly in timed'relation to the pumping elements which overlie the elongated but inadequate primary intake and discharge ports. When the primary intake and/or discharge ports through a materially lesser portion of the cycle. Thechang involume of the cavities not exposed to the intake and discharge ports in the engine block being'communicated through the cavities exposed to the intake and discharge by the balancing ports in the pump cover element.

Accordingly, among the objects of the present invention are the provision of a'pump'construc tionmountable 'directly'upona pump boss or pad cast integrally-with and incidental to operations upon the engine block "and in which boss intake and discharge openings inadequate to accommodate suificient working fluid fora full pumping cycle are disposed, and over which a pair of rotor pumping elements are positioned to be housed by a pump cover element containingsecondary distributing or balancing ports therein in timed communication with the cavities of the pumping elements through the entire pumping cycle; the provision in a pump construction as described of means for intaking the working fluid of the pump from an inadequate primary intake port directly tothe pumping elements and passing it through secondary distributing or balancing ports disposed in timed relation to the pumping elements and discharging it back to an inadequate discharge port on the same end of thepumping elements as the intake port; the provision in a pump construction as described in which inadequate rimary intake and discharge ports are disposed directly adjacent one 'endof the pumping eleare referred'to hereinafter as inadequate it will be understood to mean inadequate to supply suflicient working fluid for all the pump cavities during a complete pumping cycle, as aforementioned.

Th present invention proposes the use of a highly eflicient pump construction that has re cycle, th intake and discharge cavities of said mechanism are exposed to the intake and discharge ports in the engine block, in this instance,

ments, and secondary distributing porting bal-r ances the pressure through the entire-pumping cycle upon the opposite end of thepumping elements; the provision in "aump construction as described above in which said- -se'condary' balancing ports are accurately disposed in timed relation adj acent to the outer end of the pumping ele-' ments in a pump cover element; and the provision in a pump construction as described in which the velocity of the working fluid confined in the cavities of thepumping elements is in excess of the velocity required to fill these cavitles'whereby to carry enough excess working fluid through the pumping elements, at the position to which they are exposed to the inadequate primary ports in the engine block, to accommodate the change in' volume in the rotor elements that are not exposed to said ports, but only balanced by the lar ondary' porting in the cover element.

' Further and other objects and advantages'of the present invention reside in the novel combination and arrangement of parts, about to be described, When considered in conjunction with the awing forming a part of this specification and pointed out with particularity in the appended claims.

In the drawing like reference characters denote corresponding arts throughout the several views, and in which:

Fig. 1 i a vertical sectional view through a portion of an engine block illustrating one form of this invention; and

Fig. 2 is an elevational view of a pump boss cast integral with the engine block of Fig. l, illustrating the small elongated primary intake and dis,- charge ports cast therein, and taken on the line 2--2 thereof; and

Fig. 3 is an elevational view taken faeing the pump cover member with the pumping elements therein, on the line 3-3 of Fig. 1; and

Fig. 4 is a further elevational view similar to Fig. 3 with the pumping elements removed revealing the accurately formed and indexed see-. ondary balancing ports disposed in timed relation th umpi lement a d Fig, 5; is a'norizcntal sectional view through the pump'structure illustrating the substantially coniaucu egistration hrou o the pu p n cycle, of the elongated intake port with the distributing ports upon the opposite end, of the rotor elements, and taken substantially on the broken section line 5- -5 of Fig, 3.

Now having reference to the drawing and particularly Fig. 1, there is shown an engine block, generally designated 10, which, has an oil sump or crankcase H at the lower portion thereof. Projecting from an end wall of the block, conveniently located adjacent the end of a driving means therein, is a boss orpad l2 that is cast and cored out integral with the engine block and incidental to operations performed thereon. From the face of; the boss or pad l2 intake and di-schars Pas ge l and I5, r sp c iv ly, are drilled inwardly at any suitable angle, thereto alongwit-h the other operations performed upon the blpck to provide channels for the working fluid of the pump. In: communication with the passage or line [4 is a suction pipev l1 secured theretov by means of; a fitting" l8 and having a filter screen [-8 over the lower pipe end to strain oil inducted thereinto. The discharge passage is commumc tc w th o l g l y it c ducts: lubrican u de press to any d. poin -v In order to co nect t iapum mech ni m with a drivin m a s; n the. e ne.v a am shaft 23 is i I nai ed adjac nt hereto i a ocket for edv int-h bl .ha d rom he inner nd o t e pocket on chains.- s orme h ou h. he outer Wall of the blo k; at substantially the centralportion of the boss: or; pad 1,2;- for reception of a reduced end portion of; the: .8 m Shaft 23 which serves as the drive shaft 25 for the pumping elements. Press fitted or; otherwise suitably keyed to the drive shaft 25; a pumping element, in this case the inner; male rotor member 26-, is secured. Surrounding; the male rotor 26 is an outer female rotor 2L It; will; be apparent that the female rotor Z l has. one more internal cavity than the number-of generated; teeth on the male rotor 26 such as the pump construction described: in the mentioned patent; to which reference may be; hadf or a more cqn plete description. Disposed adjacent the outer; end of-the rotorelemerits is-apump cover element 30 having a gasket. sealin means 3| pressed tot-he- 'ooss l2 and securedinpredetermined position byany suitable fastening means- 32.

N h narc crcnc i c F s. 2 and, 4, he

4 is shown in the cover member 30, which receives the outer toothed female rotor 21 with a running fit, a pair of secondary distributing ports 34 and 35, being the intake and discharge, respectively, integral with the cover member and disposed in accurate timed relation with respect to the pumping elements 26, 21 and the said inadequate primary intake and discharge openings 1135 and 31. In order to accommodate some inaccuracy and other slight coring defects which may occur incidental to forming the engine block ID, as aforementioned, the outer ends of the intake and discharge passages l4 and I5 are cored out, or otherwise, formed, to provide small elongated ported openings 36 and 31 communicated With the said passages, respectively, as best shown in Fig. 2. While the secondary distributing porting 34 and 35 is in this instance of substantially crescent shape it will be obvious the shape of the ports maybe varied according to the requirements desired in the finished pump to meet certain operating conditions, and the specific form shown is merely for purposes of illustrating the general principle. Additionally, the principal teaching of V the invention is equally applicable to comparable pump constructions other than. rotor pumps as hereindescribed and may be employed on vane type pumps, or, other rotary pumps having a change in volume through substantially the entire pump cycle, with similar surrounding structural limitations. The secondary porting 34 and 3.51" 1:11 the inner face of the outer end of the cover mQmbe-r 30. will be hereinafter referred to generally as distributing porting in the specification and claims, since these ports are not in com-v munication with the; 'primary intake and discharge passages except through the pumping elements.

One; of the principal features of'this invention is theprovision in a rotary type pump. of the character described, in which a volume change is efiected through most of its cycle, to have the portswhich are; inadequate to accommodate. sufficient. working; fluid for a complete pumping 1 cyclev communicate with the pumping chamber through, the same.- portion of the cycle; and this isaccomplished, in the present instance by omission of a separate porting plate insert and com municating the pump rotors directly with said inadequate ports the engine block on one end and on the other opposite end of the rotors by means. of said secondary or distributing ports, which balance: the pressure through substantially theientire pump cycle, and are disposed in timed relation to-the rotor elements housed inthe pump cover member.

To illustrate the principle of intaking and discharging the' working fluid of the pump through inadequate port'means which are balanced by distributing ports formed in a pump cover element: that is disposed in timed relation to the pumping elements, there is shown in Fig. 5 a horizontal sectional. view; through the pump, as

onthe; broken line: 5-5 of'Fig. 3. From this view it-w ill; be seen that, to have a continuous efficient discharge; from the pump it is, essential that: the velocity of, the fluid Confined between the. cavie.

ties-in; the; pumping element. as, at 40 be inexcess LVolume of. the cavitiesin the pumping ele-- ,ments, during the time they are not exposed to ;said.inadequate prhnaryports36 and 31 in the block but only balanced b the secondary distributing porting '34 and 35 in the cover element '30.. Investigation and reflection will reveal this to be necessarily true and essential since without such accurate timing of thesecondary distribrelieve or discharge the'pressure built up in thefluid; A rotary pump having ports inadequate to fill the rotor spaces throughout the entire pump cycle without adequate balancing ports would beinoperative because the fluid confined in'the rotor spaces not exposed to the ports would be'raised to an excessive pressure, and the rotor spaces'notexposed to the'intake would cavitate, resulting in an extremely inefficient pumping cycle. Accordingly inthe claims, where the secondary or distributing porting is referred to as balancing or compensating cavities in the pumping elements not in communication with the inadequate intake and/or discharge ports, it will be understoodto mean that changes in volume of the working fluid in these cavitiesis accom modated or effected through communication with the adjacent distributing porting.

From the foregoing disclosures it will now be apparent there has been provided a novel pump construction directly mountable upon an engine block which has been operated upon incidental to the usual casting and machining operations thereof and may result in inadequate intake and discharge ports therein to be, communicated with one end of a set of pumping elements that are pressure balanced upon the opposite end thereof by accurate distributing ports readily incorporated in a pump cover element, thereby eliminating a separate porting plate insert, and which embodies among other things the objects and advantages of the invention first enumerated. It is to be understood, however, the specific form of the invention disclosed is merely for purposes of illustration, as many other formal modifications will now be suggested to those skilled in the art and in actual practice, which will come within the spirit and substance of the broad invention as defined by the scope of the following claims.

What I claim is:

l. The combination in a rotary pumping mechanism of the character described havinga change in volume of the working fluid efiective through a substantial portion of a pumping cycle; of housing means forming a pumping chamber, a pair of rotary pumping elements in said chamber which cooperate to define hollow cavities between them that expand and contract to produce suction and compression phases during rotation thereof, said housing means having intake and discharge ports located therein adjacent one end of said pumping elements and of inadequate length circularly of said elements to accommodate sufficient working fluid for a complete pumping cycle thereof with relation to the respective pumping cavities adjacent thereto, said housing means being provided with distributing porting therein adjacent the opposite end of said pumping elements, and said distributing porting being of suificient length circularly of said elements and disposed in accurately timed relation to the cavities in said pumping elements to balance pressures developed in the working fluid through the same portion of the pumping cycle as-first mentioned, whereby a continuous efiicient discharge is effected during that portion of the pump cycle in whicha portion of the pumping cavities communicated with said inadequate intake and discharge ports are compensated for by' the change in Volume of the working fluid in other pumping cavities communicated therewith only through the distributing porting.

2. The combination in a rotary pumping mechanism of the character described having a change in volume of the Working fluideffective through a substantial'porticn of :a pumping cycle and including intake and discharge ports communicated with the pumping mechanism through the same portion of the cycle; of housing means forming a pumping chamber, pumping elements in said chamber which cooperate to define hollow cavitiesltherebetween that expand and contract in volume to "produce suction and compression phases during rotation thereof, said housing means having an intake and a discharge port located adjacent one end of said pumping elements which ports are of inadequate length 'cir larly of said elements to accommodate suflicient Working fluid for a complete pumping cycle thereof'with relation to the respective pumping cavities, said housing means being provided with distributing porting therein at the op:

posite end of said pumping elements, and-said V distributing porting being of a suflicient length circularly of said element as to adopt said distributing porting to accommodate changes in pressure in the volume of the working fluid through substantially an entire pumping cycle on the opposite end of said pumping elements to effect a continuous eflicient discharge through the pumping elements from the first side thereof.

3. In a rotary pumping mechanism of the character described having a change in volume of the working fluid effective through a substantial portion of a pumping cycle and including intake and discharge ports communicated with the pumping mechanism through the same portion of the cycle; the combination of housing means forming a pumping chamber, pumping elements in said chamber which define hollow cavities between them that expand and contract in volume to produce suction and compression phases during rotation thereof, aid housing means having an intake distributing porting therein opening onto the opposite end of said pumping elements, the distributing porting indirectly communicated through said expanding cavities between the pumping elements with the inadequate intake port and through said contracting cavities between the pumping elements with the inadequate discharge port on the opposite end thereof, and

said distributing portings extending angularly of said elements beyond said intake and discharge ports and being so constructed and arranged that the velocity of the Working fluid in the pumping cavities connecting said inadequate intake port with its corresponding distributor port is in excess of that required to provide only the volume necessary to fill the pumping cavities in communication with the intake port, whereby to compensate for a change in volume of'theworking fluid in other pumping cavities notexposed to said intake port but only balanced'by said distributing porting:

44A rotary pumping mechanism for liquids comprising housing means forming a pumping chamber therein and rotary pumping means in said chamber, said. pumping means exerting a suctioni effect angularly of said chamber over substantially 180 thereof and: exerting a pressure effect; over substantially the remaining 180 thereof,- said: housing means having an intake port and" a discharge portopening onto one end 0f:saidcchamberserving as the sole means for in.- tro'ducing and discharging liquid to and from said chamber; saidports being so materially smaller inanguiar extent as compared to the corresponding suction and discharge effects of, said pumping mechanism as to beinadequate for complete functioning of said effects, the opposite end of said chamber having a pair of blind ports formed therein, oneof said blind ports extending over approximately the angular extent of said suction eiTect and the other of said blind ports extending over approximately the angular extent of said discharge effect, whereby to enable said pumping mechanism to exert suction and discharge effects overapproximately the complete angular extent thereof regardless of the angular inadequacies of said suction and discharge ports" by cross-flow throughsaid pumping means.

5., A rotary pumping mechanism of the character described. comprising means forming a pumping chamber and ahousing therefor; rotary pumping mean in said" housing, said pumping means exerting a. discharge and a suction efiect each overa material angular extent of said chamber'with respect to'the center of said chamher; one end of said chamber having an intake and. a; discharge port' opening thereinto and onto said pumping means, each of said ports being of an angular extent insufficient to accommodate the full angular extent of said discharge andisu'ctiorr effects and forming thersole means for inroducin and discharging liquid to and. from said chamber; and: thezopposite end ofsaid chamher: having a pair of. blindports therein opening onto said pumping means; one ofthe last-mentioned portsbeing of: an angular extent-substam tia'lly' equal to said suction effect of sai'd pumping means and being scr locatedwith respect thereto as to enable said suction effect to becompletely satisfied by flow' axially through said; pumping means from said suctionport and through said oneof saidblind-ports, and the other of said lastmentioned' ports being of an angular extent substantialiy equal to said discharge effect of said pumping means and'being'solocated with respect thereto as" to enable said discharge eiTect to be completely satisfied by-flow axially through said pumping means: from said other of said.- blind ports to said discharge port.

EUGENE S; W'ITCHGER.

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