US 3865523 A
In a rotary pump of the type providing for continuous displacement and flow of a fluid material, said pump includes a housing having an intake port and an outlet, a pair of intermating rotor means disposed for rotation within said housing, and said rotors are in communication with said inlet port and outlet so as to provide for the displacement of said fluid material. An elongated channel is formed communicating with each of the inlet port and the outlet so that as fluid material is drawn into the housing it will be exposed to the helical spacings formed along the length of the rotor means, at their point of intermeshing, and likewise said fluid material will be discharged under the induced pressure that forms along the elongated channel communicating with the outlet of said pump housing.
Description (OCR text may contain errors)
United States Patent 1191 Baehr CONTINUOUS FLOW ROTARY PUMP  Inventor: Samuel J. Baehr, La Prairie, 111.
22 Filed: Mar. 16, 1973 21 Appl. No.: 342,071
[ 1 Feb. 11, 1975 Primary Examiner-C. J. Husar Attorney, Agent, or Firm Paul M. Denk  ABSTRACT In a rotary pump of the type providing for continuous displacement and flow of a fluid material, said pump includes a housing having an intake port and an outlet, a pair of intermating rotor means disposed for rotation within said housing, and said rotors are in communication with said inlet port and outlet so as to provide for the displacement of said fluid material. An elongated channel is formed communicating with each of the inlet port and the outlet so that as fluid material is drawn into the housing it will be exposed to the helical spacings formed along the length of the rotor means, at their point of intermeshing, and likewise said fluid material will be discharged under the induced pressure that forms along the elongated channel communicating with the outlet of said pump housing.
11 Claims, 6 Drawing Figures  U.S. Cl. 418/201  Int. Cl. F0lc 1/16  Field of Search 418/201, 202
 References Cited UNlTED STATES PATENTS 1,846,700 2/1932 Ungar 418/201 2,159,744 5/1939 Maglott 418/201 2,325,617 8/1943 Lysholm et a1. 418/201 2,622,787 12/1952 Nilsson 1 418/202 3,282,495 11/1966 Walls .1 418/201 3,306,227 2/1967 Bailey 418/202 1 r 9 7 l l l. i 8 10 l- 77 SHEET 1 [IF 3 FIG.2.
PM'ENTEB FEB] 1 I975 SHEET 2 OF 3 FIG. 3.
PATENTEUFEBI 1197s SHEET 30F 3 1 CONTINUOUS FLOW ROTARY PUMP BACKGROUND OF THE INVENTION This invention relates generally to a pump, but more particularly pertains to a fluid displacement rotary pump wherein the fluid material is continuously and efficiently transferred under uniform flow with negligible pulsatory effects.
There are a multitude of various types of rotary pumps that are available in the prior art, incorporating a variety of combination of gears that furnish displacement of fluids or other materials. Most of these earlier pumps utilize some form of a star wheel of other type of longitudinally ribbed gears which simply intermesh to provide for a forced transfer of fluid, and particularly in a manner which provides a pulsatory type transfer of such fluids. For example, rotary pumps of the type defined as the Pappenheim type rotary pump and the star-wheelgeared type rotary pump show early embodiments of the type of pumps utilizing longitudinally arranged intermeshing gears. Most of these types of pumps incorporate a simple annular intake port that communicates with one side of the pump proximate the location of the intermeshing relationship between said pair of gears, while the outlet also comprises a simple pipe type discharge positioned proximate the other side of the pump and oppositely from the intake port. While some of these pumps are effective in providing displacement of liquids and gases, such as while the rib spacings or grooves of these gears convey the fluid around the inner periphery of the housing, these segmented quantities offluid are then discharged from the outlet as separate and distinct discharges which create somewhat of a pulsation or rhythmatic form of flow pattern for the pump.
The present invention obviates the deficiencies inherent in the aforesaid type of prior art rotary pumps, and improves upon their operation through the use of helical formed rotors that communicate with inlet and outlet ports along their entire length so as to provide for an overlapping and continuous intake of fluid into the pump, and simultaneously provides continuity of discharge of fluid from the same series of the rotor spacings at the same time. Hence, the pulsatory effect present in the operation of prior art pumps is eliminated by constructing the rotary pumps in the manner as will be hereinafter described. It is recognized that helically constructed gears have been utilized in screw type pumps, but it is not believed that helically formed rotors communicating along their length with the intake and discharge of fluid, has been performed.
It is, therefore, the principal object of this invention to provide a displacement type rotary pump in which fluid material is continuously taken into the pump housing and likewise discharged in a manner which eliminates any oscillatory pattern in the flow of the fluid material.
Another object of this invention is to provide a rotary pump wherein the helical rotors, or more particularly their spacings or flutes, provide a constant multiple intake of fluid material, while providing a multiple simultaneous discharge of quantities of fluid disposed within a series of said spacings of flutes from a single outlet.
Another object of, this invention is to provide a helical rotor displacement pump which may be driven from a single or dual drive means depending upon the viscosity of the material being transferred.
Another object of this invention is to provide a pump wherein its intermeshing rotor means are provided with multiple ribs or lobes, arranged helically, so that a plurality of said lobes, or more particularly there intermediate spacings, are exposed to an elongated channel communicating with the intake port to provide a form of multiple and continuous absorption or drawing in of fluid into the rotor means for immediate pumping.
An additional object of this invention is to provide a displacement pump wherein a plurality of the parabolic or conic lobes of the multi-helical ribbed rotor are exposed simultaneously to an elongated channel communicating with the outlet so as to provide for a simulta neous discharge of multiple quantities of fluid out of said pump.
These and other objects will become more apparent to those skilled in the art upon reviewing the following summary, and upon studying the description of the preferred embodiment when viewed with the drawings.
SUMMARY OF THE INVENTION This invention, as previously described, comprises a positive displacement rotary pump of the type designed for inducing transfer of fluid material, and said pump includes a casing or housing with formed cavities therein communicating with an intake port and an outlet to provide said transfer of the fluid material. The intake port and the outlet are arranged at approximate opposite sides of said casing, and are disposed within the influence and vicinity of the intermeshing between a pair of helical rotors disposed for contrarotation within said housing cavities, so that fluid may be drawn into the pump due to the pressure decrease caused at the intake port upon rotation of said rotors, and like wise, transferred or induced out of the pump at its outlet due to the pressure build up at this juncture. The unique feature of this invention is the provision of rotor means that incorporate helical formed gear like ribs and flutes, the same being intermeshed with respect to each other within the pump, and further including elongated channels, one communicating with each of the intake port and the outlet, with said channels being arranged parallel with respect to the disposition of the pair of rotors, and also being located within proximity of the meshing of said rotors. Hence, at any given moment during the operation of the pump, a series of the ribs, or lobes, and corresponding flutes will be exposed to the intake channel, while at the same time a series of the same or other ribs or flutes further around the circumference of the rotor means will be exposed to the outlet channel, communicating with the outlet port, so that while fluid is being drawn into the pump, due to the inducing and creation of low pressure at this location, said fluid will pervade within the spacings between a series of the rotor ribs, or the rotor flutes, so as to provide for a multiple intake of fluid by said contrarotating rotors, and likewise as the fluid is being discharged from the pump it will be continuously urged out of the multiplicity of spacings between said ribs or flutes as they become exposed to the elongated channel communicating with the outlet port of said pump. Hence, there is continuity in the transfer of fluid during usage of this pump means, as distinct from the type of rotary pumps available in the prior art that simply utilize gears having longitudinally oriented ribs that simply displace discrete quantities of fluid as each rib bypasses the intake port, and likewise incrimentally discharges separate quantities of fluid as these gear ribs rotate past the outlet port.
A further novel feature of this invention is that since particularly the rotor lobes are designed so that they extend approximately one hundred eighty helical degrees, more or less, around their respective rotors over their length, it is anticipated that as one end of a particular lobe spacing or flute may be completing exposure to the inlet channel its other end is just becoming exposed to the outlet channel and creating a pressure that forces fluid transfer out of the pump.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. 1 discloses an isometric view of the pump housing and external spur gears that are driven during operation of the rotary pump of this invention;
FIG. 2 provides an end view of the rotary pump disclosed in FIG. 1;
FIG. 3 provides a right side view of the rotary pump shown in FIG. 1;
FIG. 4 provides a side view of the rotor means of this invention being removed and separated from their disposition within the pump housing cavities;
FIG. 5 provides a transverse sectional view taken along the lines 55 of FIG. 3; showing the disposition of the rotor means positioned within the housing cavities and their relationship with respect to the intake port and channel, in addition to the outlet channel and port; and
FIG. 6 provides a transverse sectional view taken along a similar line as 55 of FIG. 3, but showing a modification in the design of the intake port channel.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, and more particularly in FIGS. 1 through 3, there is disclosed a casing or housing 1 for a rotary displacement pump A, having the usual intake 2 and outlet 3 disposed approximately along the sides of the housing, with the entire pump being provided with a base 4 to stabilize it during its operational use. As shown, the inlet and outlets may be provided with flanges, as at Sand 6, having the usual apertures provided therethrough, so as to provide means for hermetically sealing other conduits or pipelines thereto upon installation of said rotary pump.
Projecting externally of the casing 1 are a pair of shafts 7 and 8 each mounting a spur gear 9 and 10, respectively, said gears having the usual gear teeth, as shown, around their periphery, and being intermated to provide for contrarotation of a pair of rotors disposed within the pump as will be hereinafter described. See FIG. 4. These gears 9 and 10 are mounted for rotation upon their pair of shafts 7 and 8, as aforesaid, which project and extend outwardly of the casing 1 from their integral connection with their respective rotors 11 and 12, which are supported for intermeshing rotation within said casing. Drive means (not shown) may be provided for rotating either one of the gear 9 and 10, so as to furnish the form of rotation of the rotors l1 and 12 within said pump as previously described. It may also be noted that stub shafts 13 and 14 are integrally structured with their respective rotors l1 and 12, and are bearing mounted with respect to the opposite end of the pump housing. Preferably, these shafts 7 and 8 and 13 and 14 are bearing mounted in a fluid tight seal with respect to their end walls.
Also in FIG. 4, the two rotors 11 and 12 are shown independent and separated from their usual intermeshed mounting within the casing 1, and said rotors are each provided with helical means formed upon their surfaces that provides for their mating relationship as when rotated within the casing 1. For example, the upper rotor 11 is provided with a series of semicircular projecting ribs, or lobes, or other conic shapes, as at 15, (See FIG. 5), and they are designed for close tolerance mating within correspondingly shaped flutes 16, in this instance being semicircular as shown, formed within the peripheral surface of the rotor 12. Each lobe 15 of the rotor 11 is formed as a helix, extending approximately 180 spirally around the said rotor and extending from end to end. Likewise, each formed flute 16 provided within the surface of the rotor 12 is arranged helically around its periphery to that degree necessary to provide for its mating relationship with and adjacent lobe as the rotor 11 is revolved, and in practice, it would appear that each flute 14 is arranged spirally approximately around the surface of the rotor 12, from end to end. Obviously the angular degrees of the helically formed lobes and flutes may vary, although in the preferred embodiment, it has been found that the degrees of spiral previously described provides an effectively designed mating relationship between a rotor 11 and the rotor 12 It should also be commented at that this juncture that while the preferred embodiment discloses lobes and flutes formed upon the peripheral surface of the rotors 11 and 12, other shapes for intermating gearlike means formed upon the surface of intermeshing rotors will operate under the principles of this invention. For example, various other types of parabolic shapes for the lobes 13, and equivalent cavities or flutes 14 may operate under the principle of this invention to provide an efficient rotary pump, provided that such parabolic shapes are formed helically of their respective rotors. Also, in a modified design, it is likely that the rotor 11 may be designed of slightly greater diameter than the rotor 12, to insure proper mating of the helical means formed upon their surfaces.
Of particular significance in this invention is the relationship between the intermating of the rotor means lobes 15 within the flutes 16 provided upon and within the respective rotors 11 and 12. As previously described, the shaft 7 extends from one end of the rotor l 1, through the end wall 17 of the pump casing, and has mounted thereon the spur gear 9. Likewise, the shaft 8 correspondingly extends from the end of the rotor 12, also through the end wall 17, and has the spur gear 10 mounted thereupon. When either the shafts 7 or 8 is driven by means of a drive means (not shown), the meshing ofthe gears 9 and 10 provide for the contrarotation of their two rotors 11 and 12. Under ideal conditions, only the teeth of the spur gears 9 and 10 are in contact in their intermeshing, whereas there is only a very close tolerance fitting, perhaps only within a thousandth of an inch, although preferably not in contact, of the lobes 15 within their respective flutes 16 of the two rotors. In this manner, these two members are in close enough contact to provide for the desired reduction of pressure on the intake side of the rotary pump, and the increase of pressure upon the outlet side of said pump. In this manner, there is no frictional engagement between the two rotors 11 and 12, and no frictional contact is being effected which can cause their accelerated deterioration. On the other hand, and although such may effect a slight decrease in the efficiency of operation of the pump, it is just as likely that no spur gears may be intermeshed upon the ends of the shafts of the two rotors, but rather, one of said shafts 7 or 8 may be driven and the two rotors l1 and 12 may provide for their own driving engagement by means of a particular lobe 15 coming into contact within a mating flute 16 to provide the drive for this displacement pump. it is also shown in FIG. 5 that the two rotors 11 and 12 are arranged in close tolerance fitting within the cavities 18 and 19 of the casing 1, and said cavities are in communication so as to allow for the aforesaid mating of the rotors. This close tolerance fitting of the rotors also applies with respect to their ends which are also maintained a close tolerance relationship with the interior surfaces of the end walls 17 and 17a, or may even be sealed thereat, as through the use of O-rings, or the like.
In FIG. 5, it can be seen that the intake port 2 communicates with a channel 20 and this channel is rather elongated in length, preferably extending a corresponding distance within the casing that is equal to the length of the rotors 11 and 12, although it may be of a shorter length. Likewise, the outlet 3 also communicates with another formed channel 21, that is also elongated in design, and extends preferably the length of the casing cavities 18 and 19. The purpose of these elongated channels is to provide for exposure of a series of the lobes 15, or their intermediate spacings, in addition to the flutes l6, simultaneously to the intake port of the pump, and due to the helical formation of said lobes and flutes, intake of fluid by respective rotors will occur continuously and in an overlapping fashion due to the multiple exposure of the helical flutes and lobes to the quantity of fluid drawn into and disposed along the length of the channel 20. Furthermore, as the rotors are contrarotated, as for example, while the top rotor 11 may be rotating clockwise, and the bottom rotor 12 rotated counterclockwise, the fluid being pumped will be continuously exposed to the elongated channel 21, and its communicating outlet 3, over a series of the helical lobes and flutes, so as to provide a continuous and overlapping of fluid discharge without pulsation, from said pump. This is distinct from prior art types of rotary pumps wherein fluid is sequentially pumped by longitudinally arranged gears which causes a pulsation or incremental discharge of fluid out of an outlet port.
A slight modification in this invention is disclosed in FIG. 6 wherein is shown a more precision design for the intake port 2 communicating with a channel 22 which is once again elongated in design, as aforesaid, extending approximately the length of the rotors 11 and 12, but this channel is disclosed as having a height and depth extending about the midpoint of the rotor 11, in addition to below the midpoint of the rotor 12. More specifically, and since it was previously described that the lobes 15 on the rotor 11 are formed helically approximately l80, it can be seen that the upper reaches 23 of the channel 22 is arranged almost diametrically opposed to the upper reaches 24 of the channel 21, and in this relationship, a particular intermediate spacing between a pair of the lobes upon a rotor 11 will just become closed against the inner surface 18 of the casing 1, and just shortly thereafter the opposite end of the spacing between the same pair of lobes, which is disposed approximately l around the rotor, will just open into communication with the channel 21 to commence to discharge the pressurized fluid from the outlet 3. in a similar arrangement, the lower reach 25 of the channel 22 is disposed approximately diametrically across from the lower reach 26 of the channel 21 so that as a particular flute has been charged with fluid and becomes somewhat sealed against the inner surface 19 of the casing cavity, upon movement for a few more degrees the opposite end of said flute, which is arranged approximately around the rotor 12 probably about l40, will just commence to pass the location 26 and enter into open communication with the channel 21 for discharging its retained fluid out of the pump and its outlet.
While seven lobes and nine flutes are shown in the preferred embodiment obviously other numerical quantities oflobes and flutes can be utilized in the combined rotors of this invention. Also, while the helix of the lobes have been described as extending approximately around the rotor from end to end, it is likely that other degrees of turn can be constructed into the rotors. And in addition, if, for example, less or more than 180 is used for the spiral arrangement of the lobes, then the reaches 23 and 25 for the mofified intake channel 22 may be varied accordingly, so as to change the capacity of the pump.
It should be obvious that a variety of fluids may be transferred in this style of a rotary pump, and such fluids may comprise air or other gases, liquids, or the like. The size of the design of the outlet channel 21 will depend upon the nature of the fluid being pumped, and where the fluids are more compressible, such as a gas or an air, then the channel 21 will be designed at a lesser volume so as to allow for the pump to build up sufficient pressure of the gas forced into said chamber 21 and induce its transfer out of the outlet port 3.
Various modifications in the design of this rotary pump may occur to those skilled in the art in the light of the foregoing disclosure. The description provided is for the preferred embodiment, and any such variations, within the spirit of the principle of this invention and within the scope of the appended claims, are intended to be covered by patent protection. The described embodiment is merely illustrative of the overall principle of this invention.
Having thus described the invention what is claimed and desired to be secured by Letters Patent is:
1. In a positive displacement rotary pump of the type designed for inducing continuous transfer of fluid material comprising, a pump casing having side and end walls, said casing having a pair of communicating and parallel cavities formed therein, said casing having an intake port and an outlet port provided upon its approximate opposite sides and opening into said cavities at the location of their communication within said casing, said casing being formed having channels provided upon its interior cavity surfaces, one of said channels being in communication with the intake port, and the other of said channel being in communication with the outlet port, said channels being elongated and arranged substantially in parallel with the length of said cavities, a pair of parallelly arranged and intermeshing rotor means, one of each rotor means disposed for close tol erance rotation within each of said cavities, said rotor means intermeshing at the vicinity of the communication between said casing cavities, each rotor means having a shaft extending axially from each of its ends, said shafts being bearing mounted within the end walls of said casing, one of said rotor means including a series of helical ribs formed upon its surface, the other of said rotor means including a series of helical flutes formed upon its surface, said rotor ribs and flutes being intermeshed, a plurality of said ribs and flutes being simultaneously in communication with either the elongated intake port and outlet port channels for providing pulse-free displacement of fluid materials and the continuous discharge of multiple quantities of said fluid material along the length of said rotor means, and at least one of said intermeshed ribs and flutes always being simultaneously in communication with both the intake and outlet channels during operation of said rotary pump.
2. The invention of claim 1 wherein said helically arranged ribs and flutes of the rotor means extend approximately 140 to 180 around the rotor means, and each further extends from end to end of said rotor means.
3. The invention of claim 1 and including a drive means connecting to and providing for rotation of said rotor means.
4. The invention of claim 3 and including a pair of intermeshing spur gears, one of each spur gears operatively associated with one of said rotor means, the operation of said drive means provided for contrarotation of said spur gears and rotor means for effecting displacement of the fluid material.
5. The invention of claim 1 wherein said intake port and outlet are disposed laterally on opposite sides of said housing and proximate the location where said pair of rotor means intermate.
6. The invention of claim 1 wherein said axial shafts are bearing mounted and form a fluid tight seal in the end walls of said casing.
7. The invention of claim 1 wherein the helical ribs are in the form of projecting lobes.
8. The invention of claim 7 wherein the rotor lobes and flutes are semicircular in design.
9. The invention of claim 1 wherein said channels have a length approximating the length of the rotor means.
10. The invention of claim 1 wherein the height of the channel at the intake port has upper and lower reaches disposed approximately 180 from the respective upper and lower reaches of the channel communicating with the outlet.
11. The invention of claim 1 wherein each rib is helically formed approximately 180 around the rotor means, and each flute is formed helically approximately around its rotor means.