US3733152A

US3733152A - Rotary pump

Info

Publication number: US3733152A
Application number: US00193734A
Authority: US
Inventors: E Blackwell
Original assignee: Warren Pumps LLC
Current assignee: Warren Pumps LLC
Priority date: 1971-10-29
Filing date: 1971-10-29
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15

Abstract

A rotary pump of the twin-screw type having a lateral inlet port at one end and an axial outlet port at the other end, the outlet port being provided with a transition member containing feed screws.

Description

nited States Patent 1 11 3,733,152 Blackwell [451 May 15, 1973 s41 ROTARY PUMP 3,198,582 8/1965 [75] Inventor: Elliott H. BlackwelL Warren, Mass. 1 p 3,467,300 9/1969 [73] Asslgnee Warren umps, Inc Warren, Mass 3,535,057 10/1970 [22] Filed: Oct. 29, 1971 Primary Examiner-C. J. Husar [211 App]' 193734 Attorney-Norman S. Blodgett 52 US. cl. ..418/201 [57] ABSTRACT [51] Int. Cl. .....F0lc 1/16 A rotary pump of the twln-screw type havlng a lateral [58] Fleld of Search ..4l8/20l inlet p at one end and an axial outlet p at the other end, the outlet port being provided with a transi- [56] References C'ted tion member containing feed screws. UNITED STATES PATENTS l V l 2,745,643 5/1956 Kleinlein ..418/201 5 Claims, 2 Drawing Figures SHEET 1 0r 2 PATENIED HAY 1 5191s INVENTOR. 11101! H. Blackwell ROTARY PUMP Many technical processes involve the movement of materials which are difficult to pump; among the most difficult of these are the slurries and pulps that are encountered in paper manufacturing processes and the like. Such materials may contain stringy elements or elements that are very abrasive or chemically active. One type of pump that has proved to be very practical in pumping such materials is the rotary twin-screw type. However, even this type of pump has proved to have a relatively short life in some applications, not only because of corrosive materials getting into the bearing, but because of the difficulty in causing the flow of certain materials into the entrance port and out of the outlet port. It is possible to ameliorate but not entirely to remove these problems by use of expensive auxiliary apparatus, but the cost of doing so in the past has been prohibitive. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention. It is, therefore, an outstanding object of the invention to provide a rotary pump of a relatively simple and inexpensive nature capable of handling difficult materials with a minimum of maintenance problems.

Another object of this invention is the provision of a rotary pump for handling abrasive slurries in which the possibility of damage to bearings is minimized.

A further object of the present invention is the provision of a rotary pump of the twin-screw type in which entrance of materials into one end of the screw and out of the other end of the screw is-facilitated.

It is another object of the instant invention to provide a rotary pump of the twin-screw type in which the jamming of stringy materials at the discharge end is prevented.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

SUMMARY OF THE INVENTION In general, the invention consists of a rotary pump having a double-bored housing with a lateral inlet port at one end and an axial outlet port at the other end. Driving and driven rotors are mounted in the housing, the rotors having intermeshing helical ribs and having intermeshing gears to keep the rotors in synchronization with each other. A set of bearings is located in the housing adjacent the said one end. A transition member is attached to the housing over the outlet port and feed screws extend from the rotors at the said other end into the transition member.

More specifically, the transition member has an inlet substantially the size of the said outlet port and an outlet substantially smaller and aligned with one of the rotors. The said one of the rotors extends substantially entirely through the transition member to the outlet thereof, while the other rotor extends only part way.

BRIEF DESCRIPTION OF THE DRAWINGS The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:

FIG. 1 is a plan view with portions broken away of a pump embodying the principles of the present invention, and

FIG. 2 is a sectional view of the invention taken on the line II-Il of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, it can be seen that the rotary pump, indicated generally by the reference numeral 10, is provided with a housing 11 having twin bores 12 and 13. Extending from the bores at one end is a lateral inlet port 14 and at the other end an axial outlet port 15. A driving rotor 16 is mounted in the bore 12, while a driven rotor 17 is mounted in the bore 13. The rotors l6 and 17 are provided with intermesh ing helical ribs 18 and 19 which operate to pump fluidlike materials in the well-known manner. The rotor 16 and the rotor 17 are also provided with

intermeshing gears

21 and 22, respectively, to maintain the rotors in rotational synchronization with each other. A first set of

bearings

23 and 24 of the anti-friction, roller type are located at the ends of the rotors l6 and 17, respectively, in the housing 11 to support the rotors. At the same ends of the rotors but on the opposite side of the

gears

21 and 22 are provided another set of

bearings

25 and 26 which are also of the anti-friction, roller type to assist in the support of the rotors. The housing 11 is provided with a wall 27 which serves as one wall of an enclosure for the inlet port 14. In this wall is mounted a pair of

seals

28 and 29 which serve to seal the entrance of the

rotors

16 and 17, respectively, into the enclosed part of the housing.

The portion of the rotors l6 and 17 underlie the inlet port 14 and are provided with thin-walled, open-

mesh feed screws

31 and 32. Extending outwardly of the housing 1 1 over the outlet port 15 is a transition member 33 which, as is obvious in FIG. 2, constitutes in general an extension of the bores 12 and 13, but, as is indicated in FIG. 1, is tapered across the bore 13 into alignment with the bore 12. The rotor 16 is provided with a thin-walled open-mesh feed screw 34, while the rotor 17 is similarly provided with a feed screw 35. The transition member 33 has an inlet 36 which is substantially the size of the outlet port 15 of the housing 11 and it has an outlet 37. which is substantially smaller and which is aligned with the rotor 16.

The rotor 16 extends entirely through the transition member 33 to the outlet 37, while the rotor 17, because of the taper of the adjacent wall of the transition member, extends only part way. The feed screws 34 and 35 associated with the rotors are carried mostly on the parts of the rotors that lie in the transition member, although they extend partly into the respective bores. The

bearings

23 and 25 are shown as constituting substantially the entire support for the rotors l6 and 17, so that they are, in effect, cantilevered and lie within their bores 12 and 13, respectively.

The operation of the rotary pump 10 will now be readily understood in view of the above description. The material to be pumped enters the pump through the inlet port 14 and falls into the container surrounding the

feed screws

31 and 32. These screws forward the material toward the open end of the bores 12 and 13 where it is picked up by the helical ribs 18 and 19 manner to carry the material along the bores and to increase its pressure as it passes. The material is extruded from the ends of the bores into the transition member 33 where it is picked up by the feed screws 34 and 35, which carry it into the outlet 37 of the transition member. The transition member is, of course, suitably provided with flanges in the usual way to permit its incorporation into the fluid system.

It can be seen that the

bearings

23, 24, 2S, and 26 carry the rotors in a somewhat cantilevered manner, aside from their slight support by the

seals

28 and 29 and by the slight engagement of the ribs 18 and 19 with the surfaces of the bores 12 and 13, respectively. In any case, the

seals

28 and 29 prevent the fluid (which may be of an abrasive or corrosive nature) from gaining access to the

bearings

23, 24, 25, and 26, so that they are guaranteed an extraordinarily long life. In the failure of the material to enter the pump portion, this is overcome by the action of the

feed screws

31 and 32, while any tendency to accumulate at the output of the pump portion is overcome by the feed screws 34 and 35.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired tosecure by Letters Patent l. A rotary pump, comprising a. a double-bored housing with a lateral inlet port at one end and an axial outlet port at the other end,

b. a driving and a driven rotor mounted in the housing, the rotors having intermeshing helical ribs, the rotors also having intermeshing gears to keep the rotors in synchronization with each other,

c. a set of bearings located in the housing at the said one end to support the rotors,

d. a transition member attached to the housing over the outlet port, the transition member having an inlet substantially smaller and aligned with one of the rotors, the said one of the rotors extending entirely through the transition member to the outlet thereof, while the other rotor extends along part way, and

e. feed screws extending from the rotors at the said other end into the transition member.

2. A rotary pump as recited in claim 1, wherein the said bearings are anti-friction bearings and constitute substantially the entire support for the rotors.

3. A rotary pump as recited in claim 1, wherein the feed screws are carried on the parts of the rotors that lie in the transition member.

4. A rotary pump as recited in claim 3, wherein the rotors are provided with feed screws co-extensive with the inlet port.

5. A rotary pump as recited in claim 2, wherein the bearings consist of two axially-separated bearing for each rotor, the gears being located between the bearings.

Claims

1. A rotary pump, comprising a. a double-bored housing with a lateral inlet port at one end and an axial outlet port at the other end, b. a driving and a driven rotor mounted in the housing, the rotors having intermeshing helical ribs, the rotors also having intermeshing gears to keep the rotors in synchronization with each other, c. a set of bearings located in the housing at the said one end to support the rotors, d. a transition member attached to the housing over the outlet port, the transition member having an inlet substantially smaller and aligned with one of the rotors, the said one of the rotors extending entirely through the transition member to the outlet thereof, while the other rotor extends along part way, and e. feed screws extending from the rotors at the said other end into the transition member.