High pressure piston pump for fluent materials

• US 5,094,596 A
• Filed: 06/01/1990
• Issued: 03/10/1992
• Est. Priority Date: 06/01/1990
• Status: Expired due to Term

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Binks Manufacturing Company
• Inventors: Erwin, Larry R., Hetherington, Robert D., Cavanaugh, James E.
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): FREAY, CHARLES GRANT
• Application Number:
  US07/531,850
• Time in Patent Office: 648 Days
• Field of Search: 417/397, 417/503, 417/568
• US Class Current: 417/397
• CPC Class Codes: F04B 15/02 the fluids being viscous or non-homogeneous
• CPC Class Codes: F04B 9/113 reciprocating movement of the pumping members being obtained by a double-acting liquid motor

Abstract

A pump assembly especially adapted for pumping viscous and/or abrasive materials is comprised of a pair of opposed single acting piston pumps operated alternately by an interposed reciprocal actuator, and a static chamber interposed between each pump and the actuator; each pump comprising a pumping chamber having aligned inlet and outlet check valves in its peripheral wall and defining a straight line path of fluid flow diametrically through the chamber, a piston having its periphery spaced from the peripheral wall of the pumping chamber and having a relatively short stroke to maintain the straight line path of fluid flow through the chamber, and an annular seal extending from the peripheral wall of the pumping chamber toward the piston and bridging the gap between the periphery of the piston and the peripheral wall of the pumping chamber, the piston having sealed engagement with the seal throughout its reciprocal path of movement; the static chambers isolating the two pumps and the actuator from one another so that fluid leakage from any of them will not adversely affect the others. The pump assembly facilitates pressurized or forced feeding of fluent material to the two pumps, and therefore, the pumping of extremely viscous fluent materials, and utilization of the assembly in a wide variety of systems applications.

Claims

1. A pump assembly especially adapted for pumping viscous and abrasive fluent materials comprising

a reciprocal actuator having a short reciprocatory stroke,

a pump unit at one side of said actuator, said pump unit comprising means defining a static chamber adjacent said actuator, said static chamber having a peripheral wall with a vent port therethrough, said static chamber being open at the end thereof remote from said actuator,

an outlet block adjacent said static chamber defining a pumping chamber coaxial with said static chamber, said pumping chamber having a peripheral wall and an end wall remote from said static chamber, said pumping chamber being open at the end thereof adjacent said open end of said static chamber, said pumping chamber peripheral wall being aligned with said static chamber peripheral wall,

means for securing the open end of said output block to the open end of said static chamber means and for securing said static chamber means to said actuator,

a piston reciprocable axially within said static and pumping chambers and movable forwardly toward and rearwardly away from said end wall of said pumping chamber, said piston being of smaller diameter than and having its periphery in inwardly spaced gap relation to the peripheral walls of said chambers,

an annular seal clamped by said securing means between the peripheral walls of said output block and said static chamber means at their open ends and sealing said walls one to the other, said seal extending radially inwardly into engagement with the periphery of said piston and including a flexible annular lip engaging the periphery of said piston and extending toward said pumping chamber for wiping and sealing engagement with the periphery of said piston,

a piston rod extending from said piston through said static chamber to said actuator and coupling said piston with said actuator for imparting short reciprocal strokes of movement to said piston, said piston being of a length in relation to its reciprocal path of movement that the periphery of said piston remains continuously in engagement with said seal and engages only said seal,

an inlet extending through the peripheral wall of said pumping chamber contiguous to the end wall of said pumping chamber,

means for introducing into said inlet fluent material to be pumped,

an inlet check valve in said inlet between said pumping chamber and said fluent material introducing means,

an outlet extending through the peripheral wall of said pumping chamber contiguous to the end wall of said pumping chamber, and

an outlet check valve in said outlet,

said actuator reciprocating said piston through a rearward suction stroke for drawing fluent material into said pumping chamber through said check valved inlet and a forward pressure stroke for forcing fluent material from said pumping chamber through said check valved outlet,

said inlet and outlet being aligned with one another and in conjunction with said piston providing a short and essentially straight line path for fluid flow of fluent material substantially diametrically through said pumping chamber contiguous to the end wall of said pumping chamber,

said actuator reciprocating said piston through short reciprocal strokes from a forward position closely adjacent the end wall of said pumping chamber to a rearward position spaced a short distance from said end wall for establishing and maintaining substantially straight line flow of fluent material diametrically through said chamber contiguous to said end wall from said inlet to said outlet,

said static chamber spacing said pumping chamber from said actuator, said vent through the peripheral wall of said static chamber comprising a drain, said static chamber being vented through said drain and physically isolating said pumping chamber from said actuator.

2. A pump as set forth in claim 1, said fluent material introducing means supplying fluent material to said inlet under positive pressure.

3. A pump as set forth in claim 1, including a second inlet to said pumping chamber, means for introducing a second fluid to said second inlet, and a second inlet check valve in said second inlet between said pumping chamber and said second fluid introducing means, said piston on its suction stroke drawing fluent material and the second fluid through said check valved inlets into said pumping chamber and on its pressure stroke forcing a mixture of the fluent material and the second fluid through said check valved outlet.

4. A pump assembly as set forth in claim 1, said static chamber receiving from said pumping chamber any fluent material that may leak past said seal and including means for returning said fluent material for recirculation to said fluent material introducing means.

5. A pump assembly as set forth in claim 1, said static chamber receiving from said pumping chamber and draining through said vent therein any fluent material that may leak past said seal, said actuator comprising a fluid actuated dual acting reciprocatory motor and including means for sealing said piston rod relative to said motor, said static chamber receiving from said motor and venting through said vent therein any actuating fluid that may leak past said piston rod sealing means.

6. A pump assembly as set forth in claim 1, including a second one of said pump units on the other side of said actuator and actuated by said actuator alternately with the first named pump unit, the static chamber means, output blocks and pistons of the two pump units being of modular construction and interchangeably mountable on the actuator to faciliate variations in the pumping characteristics of the two units in one or more of pressure, volume and fluent material pumped.

7. A pump assembly as set forth in claim 1, wherein said short reciprocal strokes of said piston is a stroke of between 11/2 and 2 inches, and said piston has a diameter of between 11/2 and 31/2 inches.

8. A pump assembly as set forth in claim 1, wherein said short reciprocal strokes of said piston is a stroke of a distance no greater than the diameter of said piston.

9. A pump assembly for pumping fluent materials comprising

an outlet block defining a pumping chamber, said pumping chamber having a cylindrical peripheral wall and an end wall;

a static block defining a static chamber, said static block abutting said outlet block, said static chamber having a cylindrical peripheral wall coaxial with and of substantially the same diameter as said pumping chamber peripheral wall, said static chamber having a vent to the atmosphere;

a piston reciprocal within said pumping chamber and said static chamber, said piston being of smaller diameter than and having its periphery in inwardly spaced gap relation to the peripheral walls of said pumping chamber and said static chamber;

an annular seal clamped between said outlet block and said static block, said seal extending radially inwardly into engagement with the periphery of said piston, said seal sealing said outlet block to said static block and said outlet block to said piston, the periphery of said piston being in continuous engagement with said seal and only said seal and remaining spaced from all other surfaces within the pump;

an inlet to said output block, said inlet having a check valve;

an outlet from said output block, said outlet having a check valve; and

means for reciprocating said piston within said pumping chamber and said static chamber.

10. A pump assembly as in claim 9, wherein said reciprocating means reciprocates said piston through strokes having a distance shorter than the diameter of said piston.

11. A pump assembly especially adapted for pumping viscous and abrasive fluent materials comprising

a fluid actuated dual acting reciprocatory motor having a horizontal axis of reciprocation and a short reciprocatory stroke,

a pump unit on each of the opposite sides of said motor, each said pump unit comprising

a static block next to said motor defining a cylindrical static chamber coaxial with said motor, said static chamber having a peripheral wall with a downwardly open vent port therethrough and being axially open at the end thereof remote from said motor,

an outlet block next to said static block defining a cylindrical pumping chamber coaxial with said motor and said static chamber, said pumping chamber being axially open at the end thereof next to said static chamber, having a peripheral wall of substantially the same diameter as said static chamber peripheral wall and including a blind end wall at the end thereof remote from said static chamber,

means for securing the axially open end of said output block to the axially open end of said static block and for securing said static block to said motor,

a cylindrical piston reciprocable coaxially within said static and pumping chambers and movable forwardly toward and rearwardly away from said end wall of said pumping chamber, said piston being of smaller diameter than and having its periphery in inwardly spaced gap relation to the peripheral walls of said chambers,

an annular seal clamped by said securing means between the peripheral walls of said output block and said static block at said open ends thereof and sealing said blocks one to the other, said seal extending radially inwardly into engagement with the periphery of said piston and including a flexible annular lip engaging the periphery of said piston and extending toward said pumping chamber for wiping and sealing engagement with the periphery of said piston,

a piston rod extending axially from said piston through said static chamber to said motor and coupling said piston with said motor for imparting short reciprocal strokes of movement to said piston, said piston being of a length in relation to its reciprocal path of movement that the periphery of said piston remains continuously in engagement with said seal and engages only said seal,

an inlet extending downward through the peripheral wall of said pumping chamber contiguous to the end wall of said pumping chamber,

means for introducing into said inlet fluent material to be pumped,

an inlet check valve in said inlet between said pumping chamber and said fluent material introducing means,

an outlet extending substantially vertically upward through the upper portion of the peripheral wall of said pumping chamber contiguous to the end wall of said pumping chamber in essentially diametrical alignment with said inlet, and

an outlet check valve in said outlet,

said motor reciprocating said piston through a rearward suction stroke for drawing fluent material into said pumping chamber through said check valved inlet and a forward pressure stroke for forcing fluent material from said pumping chamber through said check valved outlet,

said inlet and outlet being aligned with one another and in conjunction with said piston providing a short and essentially straight line path for fluid flow of fluent material substantially diametrically through said pumping chamber contiguous to the end wall of said pumping chamber,

said motor alternately reciprocating each of said pistons through short reciprocal strokes from a forward position closely adjacent the end wall of the respective pumping chamber to a rearward position spaced a short distance from said end wall for establishing and maintaining substantially straight line flow of fluent material diametrically through the respective pumping chamber contiguous to said end wall from said inlet to said outlet,

each said static chamber spacing the respective pumping chamber from said motor and isolating the respective pumping chamber and said motor from one another, each said static chamber receiving and venting through said vent therein any fluent material leaking from the respective pumping chamber and any actuating fluid leaking from said motor.