Drive system for a positive displacement pump

Patent metadata

Field	Value
Publication number	US-11867165-B2
Application number	US-202117348309-A
Country	US
Kind code	B2
Filing date	Jun 15, 2021
Priority date	Feb 7, 2014
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A drive system for a pump includes a housing, first and second fluid displacement members, and a reciprocating member configured to mechanically displace the first and second fluid displacement members through respective suction strokes. The housing and fluid displacement members define an internal pressure chamber configured to be filled with a working fluid having a charge pressure. The internal pressure chamber is configured such that the working fluid simultaneously exerts the charge pressure on the first and second fluid displacement members.

First claim

The invention claimed is:

1. A drive system for a displacement pump, the drive system comprising:
a first housing at least partially defining an internal pressure chamber configured to be filled with a working fluid having a charge pressure, the working fluid being one of a compressed gas and a non-compressible hydraulic fluid under pressure;
a reciprocator disposed within the first housing and configured to be driven along a first axis;
an electric displacer operably connected to the reciprocator to drive reciprocation of the reciprocator along the first axis;
a first diaphragm disposed at a first end of the first housing, the first diaphragm at least partially defining the internal pressure chamber;
a second diaphragm disposed at a second end of the first housing, the second diaphragm at least partially defining the internal pressure chamber;
wherein the reciprocator is connected to the first diaphragm and the second diaphragm to mechanically displace the first diaphragm through a first suction stroke and to mechanically displace the second diaphragm through a second suction stroke;
wherein the internal pressure chamber is configured such that the working fluid exerts the charge pressure on the first diaphragm and on the second diaphragm during both a first pressure stroke of the first diaphragm and a second pressure stroke of the second diaphragm.

2. The drive system of claim 1 , wherein the first diaphragm, the second diaphragm, and the reciprocator are disposed coaxially on the first axis.

3. The drive system of claim 2 , further comprising:
a first fluid cover abutting the first end of the first housing, wherein a circumferential edge of the first diaphragm is retained between the first fluid cover and the first housing.

4. The drive system of claim 2 , wherein:
the first diaphragm includes a first attachment screw;
the reciprocator is connected to the first attachment screw.

5. The drive system of claim 1 , wherein the reciprocator is connected to the first diaphragm by a first intermediate member and connected to the second diaphragm by a second intermediate member.

6. The drive system of claim 1 , wherein the electric displacer includes an electric motor disposed outside of the first housing.

7. The drive system of claim 6 , wherein the electric displacer further comprises a gear reduction drive connected to the electric motor to receive a rotational output from the electric motor and connected to the reciprocator to drive reciprocation of the reciprocator.

8. The drive system of claim 7 , wherein the gear reduction drive includes a crank shaft configured to rotate on a second axis and a cam follower offset from the second axis and configured to rotate about the second axis, and wherein the cam follower extends into a slot of the reciprocator.

9. The drive system of claim 1 , wherein the internal pressure chamber is configured to be filled with the working fluid throughout both the first pressure stroke and the first suction stroke without the working fluid being exhausted from the internal pressure chamber.

10. The displacement pump of claim 9 , wherein the first diaphragm includes a first flexible membrane, wherein a circumferential edge of the first flexible membrane is secured between a first cover connected to the first housing and the first housing, wherein the first diaphragm fluidly separates a first process fluid chamber defined by the first cover and the first diaphragm from the internal pressure chamber, and wherein the charge pressure is configured to bias the first flexible membrane into the first process fluid chamber during both the first pressure stroke and the first suction stroke.

11. The displacement pump of claim 1 , wherein the electric displacer is configured to generate a rotational output to drive reciprocation of the reciprocator along the first axis.

12. A displacement pump comprising:
a housing at least partially defining an internal pressure chamber configured to be filled with a working fluid having a charge pressure, the working fluid being one of a compressed gas and a non-compressible hydraulic fluid under pressure;
a reciprocator disposed within the housing and configured to be driven along a first axis;
an electric motor configured to generate a rotational output on a second axis;
a drive connected to the electric motor and the reciprocator, the drive configured to convert the rotational output from the electric motor to a linear reciprocating motion to cause the reciprocator to reciprocate along the first axis;
a first cover at least partially defining a first process fluid cavity;
a second cover at least partially defining a second process fluid cavity, wherein the housing is disposed axially between the first cover and the second cover;
a first diaphragm at least partially defining the first process fluid cavity on a first side of the first diaphragm and at least partially defining a first chamber on a second side of the first diaphragm, the first chamber fluidly separated from the first process fluid cavity by the first diaphragm; and
a second diaphragm at least partially defining the second process fluid cavity on a first side of the second diaphragm and at least partially defining a second chamber on a second side of the second diaphragm, the second chamber fluidly separated from the second process fluid cavity by the second diaphragm;
wherein the first diaphragm and the second diaphragm are connected to the reciprocator such that the reciprocator mechanically displaces the first diaphragm through a first suction stroke and mechanically displaces the second diaphragm through a second suction stroke; and
wherein the internal pressure chamber includes the first chamber and the second chamber, and wherein the internal pressure chamber is configured such that the working fluid concurrently exerts the charge pressure on the second side of the first diaphragm and on the second side of the second diaphragm.

13. The displacement pump of claim 12 , wherein the internal pressure chamber further comprises a passage disposed within the first housing that extends between and fluidly connects the first chamber and the second chamber.

14. The displacement pump of claim 13 , wherein the passage includes a plurality of passages.

15. The displacement pump of claim 12 , wherein the first diaphragm includes a first flexible membrane, wherein a circumferential edge of the first flexible membrane is secured between the first cover and the housing, and wherein the internal pressure chamber is configured such that the working fluid exerts the charge pressure on the first diaphragm during both a first pressure stroke of the first diaphragm and the first suction stroke to bias the first flexible membrane into the first process fluid chamber.

16. The displacement pump of claim 15 , wherein the second diaphragm includes a second flexible membrane, wherein a circumferential edge of the second flexible membrane is secured between the second cover and the housing, and wherein the internal pressure chamber is configured such that the working fluid exerts the charge pressure on the second diaphragm during both a second pressure stroke of the second diaphragm and the second suction stroke to bias the second flexible membrane into the second process fluid chamber.

17. The displacement pump of claim 12 , wherein the working fluid is in contact with the second side of the first diaphragm and the second side of the second diaphragm during the first suction stroke and during a first pressure stroke of the first diaphragm.

18. The dis

Assignees

• Graco Minnesota Inc

Inventors

• Hines Bradley H
• Koehn Brian W
• Earles Jeffrey A
• Scheierl Paul W
• Collins Adam K

Classifications

• F04B27/10

  having stationary cylinders · CPC title

• F04B1/14

  having stationary cylinders · CPC title

• F04B45/047

  Pumps having electric drive · CPC title

• F04B53/1002

  Ball valves · CPC title

• F04B35/01

  the means being mechanical · CPC title