FreshPatents.com Logo
stats FreshPatents Stats
n/a views for this patent on FreshPatents.com
Updated: October 26 2014
newTOP 200 Companies filing patents this week


    Free Services  

  • MONITOR KEYWORDS
  • Enter keywords & we'll notify you when a new patent matches your request (weekly update).

  • ORGANIZER
  • Save & organize patents so you can view them later.

  • RSS rss
  • Create custom RSS feeds. Track keywords without receiving email.

  • ARCHIVE
  • View the last few months of your Keyword emails.

  • COMPANY DIRECTORY
  • Patents sorted by company.

Follow us on Twitter
twitter icon@FreshPatents

Air-driven hydraulic pump with pressure control

last patentdownload pdfdownload imgimage previewnext patent


20120315163 patent thumbnailZoom

Air-driven hydraulic pump with pressure control


A hydraulically driven pump with driving pressure controlled within a predetermined range. The hydraulically driven pump has a driving-fluid port fluidly coupled to a compressed air source and ambient, a driven-fluid inlet port fluidly connected to a tank, and a driven-fluid outlet port. A pressure sensor is used for providing sensing values indicative to the driving pressure in the hydraulically driven pump, and the driving pressure is controlled in closed loop by releasing and filling air through the driving-fluid port. The hydraulically driven pump has a suction stroke, in which driven fluid is refilled into the pump, and a pressing stroke, in which driven fluid is pressed out. A hydraulic buffer is used to provide driving pressure during a suction stroke and two hydraulically driven pumps can work alternately in providing continuous pressure control.

Inventors: Mi Yan, Baohua Qi
USPTO Applicaton #: #20120315163 - Class: 417375 (USPTO) - 12/13/12 - Class 417 
Pumps > Motor Driven >Fluid Motor

view organizer monitor keywords


The Patent Description & Claims data below is from USPTO Patent Application 20120315163, Air-driven hydraulic pump with pressure control.

last patentpdficondownload pdfimage previewnext patent

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX

Not Applicable

FIELD OF THE INVENTION

This present application claims priority from U.S. provisional application No. 61/520,630 having the same title as the present invention and filed on Jun. 13, 2011.

This invention relates to pumps, and more particularly, to hydraulic injection pumps used in injecting fluid into a vessel, the pressure inside which is controlled within a predetermined range.

BACKGROUND OF THE INVENTION

Air-driven hydraulic pumps use compressed air to drive reciprocating actions in delivering pressurized liquid. With a stepped piston having its large diameter side contacting compressed air in an air cylinder and small diameter side driving liquid in a high pressure injection cylinder, an air-driven hydraulic pump is able to provide high driving pressure, which is multiple times of compressed air pressure, and the multiplication ratio is determined by the ratio of the large diameter to the small diameter. To complete a reciprocation cycle, which includes a suction stroke and a pressing stroke, it needs to control the air pressure inside the air cylinder by filling and releasing compressed air. Normally, the pressure control is realized by using relay valves that use sealed air and switches to fill and release the sealed air in controlling the relay valves (U.S. Pat. Nos. 3,963,383, 4,645,431, and 6,386,841). Therefore, the reciprocating rate is determined by air pressure, air filling and releasing rate, and switch position. As a result, fluctuations in compressed air supply pressure affect both reciprocating rate and driving pressure. Also, in the pressing stroke, compressed air expands and results in pressure drop. The pressure change in compressed air is then amplified by the pump and causes larger change in driving pressure.

To accurately control the driving pressure, a primary object of the present invention is to provide controls means to adjust the driving pressure, thereby with a closed-loop control, the driving pressure can be controlled within a predetermined range.

A further object is to replace the relay valve using the controls means set forth in the foregoing object to provide a simplified pump structure.

A further object is to provide controls means to avoid the effects of the suction stroke in controlling driving pressure.

BRIEF

SUMMARY

OF THE INVENTION

In accordance with the present invention, a hydraulically actuated pumping apparatus with driving pressure controlled within a predetermined range is provided.

According to one embodiment of the invention, an air-driven hydraulic injection pump is provided that has a pressure multiplication ratio of 1.0, however, has no piston device inside. The stroke control and pressure control are accomplished by energizing and de-energizing two solenoid valves to control air pressure inside the pump according to pressure sensing values obtained from a pressure sensor.

According to another embodiment of the invention, an air-driven hydraulic injection pump is provided that has a pressure multiplication ratio higher than 1.0. This pump has a piston inside and strokes and pressure are controlled by energizing and de-energizing two solenoid valves to release and fill compressed air according to pressure sensing values obtained from a pressure sensor.

According to another embodiment of the invention, a hydraulic buffer is provided with an air-driven hydraulic injection pump. The hydraulic buffer decreases pressure drops associated with suction strokes in which compressed air is released from the pump.

According to another embodiment of the invention, a hydraulically driven pump system including two air-driven hydraulic injection pumps are provided. These two pumps work alternately to control driving pressure within a predetermined range.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a depicts an air-driven hydraulic pump system with two two-way solenoid valves and a pump without piston;

FIG. 1b depicts an air-driven hydraulic pump system with a two-way solenoid valve, a three-way solenoid valve, and a pump without piston;

FIG. 2 is a flow chart of a control algorithm for controlling strokes and pressure;

FIG. 3 depicts a cross sectional elevation view of a hydraulic pump housing used with the same stroke and pressure controls in a system as shown in FIG. 1;

FIG. 4 depicts a cross sectional elevation view of a hydraulic pump housing and a hydraulic buffer that is to decrease pressure drops associated with suction strokes;

FIG. 5 illustrates a timing chart of pressure changes in systems with and without a hydraulic buffer;

FIG. 6 depicts a system with two hydraulic pumps working together to control driving pressure within a predetermined range;

FIG. 7 is timing chart of control mode changes in a system shown in FIG. 6

DETAILED DESCRIPTION

OF THE INVENTION

Referring to FIG. 1a, a pump 100 includes a gas port 101, a liquid inlet port 105, a liquid outlet port 102, and a pressure sensor 103. Through a liquid passage 132, the liquid inlet port 105 is fluidly connected to a port 131 of a liquid tank 130, which contains a fluid 133. Inside the inlet port 105, a check valve 106 only allows liquid to flow from the liquid tank 130 to the pump 100. Fluid in the pump 100 flows out through the liquid outlet port 102, which has a check valve 104 included, while pressure inside the pump is measured by the pressure sensor 103 and the sensing value is sent to a controller 110. The gas port 101 of the pump 100 is fluidly coupled to the outlet of a two-way solenoid valve 126 through a Tee connector 127 and an air passage 125, and the inlet of the solenoid valve 126 is connected to a compressed air supply (not shown in FIG. 1a). The Tee connector 127 is also fluidly connected to the inlet of another two way solenoid valve 122 through an air passage 121. To lower down the noise when releasing air, an optional muffler 124 can be connected to the outlet of the solenoid valve 122 through an air passage 123. Both of the solenoid valves 122 and 126 are electrically connected to the controller 110. At normal states, i.e., before the solenoid valves 122 and 126 are energized, the compressed air is disconnected to the gas port 101 and the gas port 101 is fluidly connected to ambient through the solenoid valve 122.

Stroke control and pressure control for the pump 100 are accomplished by using the combination of controls to the solenoid valves 122 and 126. The controls to the two valves have four modes shown in the following table:

TABLE 1 Mode Status of the Status of the

Download full PDF for full patent description/claims.

Advertise on FreshPatents.com - Rates & Info


You can also Monitor Keywords and Search for tracking patents relating to this Air-driven hydraulic pump with pressure control patent application.
###
monitor keywords



Keyword Monitor How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Air-driven hydraulic pump with pressure control or other areas of interest.
###


Previous Patent Application:
Sealing device for an immersible pump
Next Patent Application:
Cost reduced variable geometry turbocharger with stamped adjustment ring assembly
Industry Class:
Pumps
Thank you for viewing the Air-driven hydraulic pump with pressure control patent info.
- - - Apple patents, Boeing patents, Google patents, IBM patents, Jabil patents, Coca Cola patents, Motorola patents

Results in 0.65931 seconds


Other interesting Freshpatents.com categories:
Tyco , Unilever , 3m

###

Data source: patent applications published in the public domain by the United States Patent and Trademark Office (USPTO). Information published here is for research/educational purposes only. FreshPatents is not affiliated with the USPTO, assignee companies, inventors, law firms or other assignees. Patent applications, documents and images may contain trademarks of the respective companies/authors. FreshPatents is not responsible for the accuracy, validity or otherwise contents of these public document patent application filings. When possible a complete PDF is provided, however, in some cases the presented document/images is an abstract or sampling of the full patent application for display purposes. FreshPatents.com Terms/Support
-g2-0.2728
     SHARE
  
           


stats Patent Info
Application #
US 20120315163 A1
Publish Date
12/13/2012
Document #
13495853
File Date
06/13/2012
USPTO Class
417375
Other USPTO Classes
International Class
04B19/20
Drawings
9



Follow us on Twitter
twitter icon@FreshPatents