US3183839A

US3183839A - Pump control

Info

Publication number: US3183839A
Authority: US
Publication date: 1965-05-18
Anticipated expiration: 1982-05-18

Description

May 18, 1965 Filed May 16, 1963 V. A. BRUNSON ETAL PUMP CONTROL 2 Sheets-Sheet l XNVENTORS. VIR61L A. BRUNSON I iirgil A. Brunson 3,183,839 PUMP CONTROL and Harold L. Vandcn Hock, Grand Rapids, Mich, assignors to Blacitmer Pump Company, Grand Rapids, Mich, a company of Michigan Filed May 16, 1963, Ser. No.280,841 4 Claims. (Cl. 103-21) This invention relates to pumps and pump controls.

Positive displacement pumps'have been used extensively for pumping liquids or fluids into confined spaces having ample storage capacity, such as tanks partially filled with air. However, the use of such pumps for pumping into systems having little or no storage capacity has not been completely satisfactory and has required relatively complicated systems. A major difliculty when pumping into a closed system having little or no storage capacity is the difficulty of control of the pumping rate when the outlet of such system is throttled or closed.

Accordingly, the objects of this invention are to improve pumping systems, to simplify such systems, to provide such a system having a low regulated pressure, substantially independent of pump speed, when there is no flow in the discharge system and having a higher regulated pressure when fiow exists in the discharge system, to provide a positive displacement pump with control means responsive to flow in the discharge system for adjusting valve means in the pump by air pressure to produce said regulated pressures, to provide such a pump with a built-in air controlled bypass, to provide such a pump having superior simplicity, and to use air pressure, in a pump regulating valve, to select one of two fixed positions for the normally fixed end of a regulator spring inlet port, a diaphragm closing the opening, a cap form-- ing a chamber over the diaphragm, and resilient means between the diaphragm and the valve urging the valve toward its closed position. Control means are provided communicating with the chamber and responsive to the flow in the discharge system for supplying air under pressure to the chamber to drive the diaphragm toward the valve compressing the resilient means between the diaphragm and the valve when fiow exists in the discharge system and to exhaust air from the chamber permitting the resilient means to expand and push the diaphragm away from the valve when there is no flow in the discharge system. The resilient means in itscompressed condition maintains a high regulated pressure in the outlet port and in its expanded condition maintains a low regulated pressure in the outlet port.

In accordance with the above, one feature of this invention resides in providing the pump with a'built-in air controlled bypass. This produces a pump of superior simplicity, simplifying and lowering the cost of the system.

Another feature resides in providing pressure regulation at both low pressure setting and the high pressure setting of the resilient means. a low regulated pressure, substantially independent of pump speed, when there is no flow in the discharge system and ahigher regulated pressure when flow exists in the discharge system.

Still another feature resides-in using air pressure to The pumping system has 3,133,839 Patented May 18, 1965 ice select one of two fixed positions for the normally fixed end of the resilient means.

The above and other objects and features of this invention will be appreciated more fully from the following detailed description when read with reference to the accompanying drawings wherein:

FIG. 1 is a vertical section of a positive displacement pump incorporating the built-in air controlled bypass; and

FIG. 2 is a schematic diagram of an improved pumping system constructed according to the invention.

Referring to the drawings, a rotary sliding vane pump 10 includes a housing 11 having an inlet port 12 and an outlet port 13. These ports may be fitted with threaded couplings or other means for attaching pipes to the pump. A shaft 14, extending transversely through the pump housing 11, carries a circular cylindrical rotor 15 that fits within a rotor chamber 16 in the housing 11.

The rotor chamber 16 includes, as a wall thereof, an interior partition 17 of the housing 11 having a cylidrical surface concentric with the shaft 14 at a radius equal to the radius of the rotor 15. Diametrically opposite the partition 17, the rotor chamber 16 is formed by a portion 18 of the bottom wall of the housing 11. This portion is concentric with respect to the shaft 14 at a radius sufliciently greater than the radius of the rotor 15 to provide pumping chambers in the space between the rotor 15 and the wall portion 18.

The rotor 15 has a plurality of radial slots 19 extending parallel to the shaft 14 to receive sliding vanes 26 which in cooperation with the exterior surface of the rotor 15 and interior surface of the chamber 16 provides a series of pockets or chambers for transporting fluid from the inlet port 12 to the discharge port 13.

The rotor 15 has axially extending pockets 22 at the base of each of the slots 19 and the forwardly facing sides of the vanes 20 are grooved as indicated by the dotted lines 23 to form communicating passages between the pockets or chambers formed ahead of the vanes 20 and the rotor pockets 22. The grooves 23 provide free communication between the pumping chambers ahead of the vanes 20 and the pockets 22 so that the vanes 20 may freely slide radially in the slots 19. Furthermore, by letting each of the pockets 22 communicate with the chamber ahead of the vane the pressure in the chamber is employed to hold the vane against the exterior wall of the rotor chamber 16.

To further assist the centrifugal force, as the rotor 15 turns, in throwing the vanes 24) outwardly into contact with the wall of the chamber 16 a plurality of push rods 24 extending diametrically through the rotor 15 are provided so thatas one of a pair of vanes is pushed inwardly by contactwith a contracting portion of the chamber wall the diametrically opposite vane is pushed outwardly to keep it in contact with an expanding portion of the wall of the chamber 16.

A bypass duct 25 leading from the outlet port 13 past a disk valve 26 to the inlet port 12 is provided in the housing 11. The valve 26 controls the flow through the passage 25. The valve 26 is shown as a disk valve although other types such' as piston valves, ball seat valves or angular seat valves may be employed as long as the outlet pressure of the pump tends to open the valve. The

- disk valve 26 seats at 27 and is carried on a Valve guide a} the right hand disk 34 against a spring mounting 37 carried by the right hand end of the stem 35. A second spring mounting 38 is carried by the valve disk 26 and the ends of a regulator coil spring 39 receive the

mountings

37 and 38, the regulator spring 39 being compressed between the respective diaphragm disk 34 and the valve disk 26 urging the valve towards its seat 27, i.e., toward its closed position.

The diaphragm stem 35 is axially slidable in an opening {it in the cup 32. An adjustment nut 41 on the left hand end of the stem 35 exterior of the cup 32 acts as a stop limiting movement of the stem 35 to the right by engaging the cup 32. A lock nut 42 maintains the adjusted position of the adjustment nut 41. The ring 36 and the cup 32 are held in place by means of screws 43, only one of which is shown, at an opening 44 defined by a wall of the housing 11. The opening 44, which is closed by the diaphragm 29, is in communication with the passage 25 and is between the valve 26 and the inlet port 12.

The valve 26 is an air pressure adjusted relief valve, its body being made up of the ring 36, the cup 32 and that part of the pump housing 11 at the valve 26, the valve seating at 27 in the pump. One of the features of the pump resides in the built-in air controlled bypass which simplifies and lowers the cost of the system. The diaphragm 29 is movable under the influence of air pressure (air supplied to the chamber 33 through tubing 45) in opposition 'to the regulator spring 39 to a position determined by engagement of the stop, i.e., adjustment nut 41, with the valve body to compress the regulator spring for high pressure valve operation and is returned by the regulator spring in the absence of the air pressure to permit low pressure valve operation. The stop 41 is adjustable to select the desired high pressure. The stop 41 and truck pumpsystem. Such a system has little or no storage capacity. The air pressure adjusted relief valve 26 gives good control of the pumping rate when the outlet of such system is throttled or closed. Control means, hereinafter described, are provided which communicate with the chamber 33 through the tubing 45 and are responsive to the flow in the discharge system for supplying air under pressure to the chamber 33 to drive the diaphragm toward the valve seat 27 compressing the regulator spring 39 between the diaphragm disk 34 and the valve disk 26 when flow exists in the discharge system and to exhaust air from the chamber 33 permitting theregulator spring 39 to expand and push the diaphragm 29 away from the valve. seat 27 when there is no flow in the discharge system. The regulator spring 39 in its compressed condition maintains a high regulated pressure in the outlet port 13 and in its expanded condition maintains a low regulated pressure in the outlet port 13. One of the features of the system resides in providing pressure regulation at both the low pressure-setting and the high pressure charge system. -Anather feature resides in using air pressure to select one of two fixed positions for the normally fixed end of the regulator spring 39.

The fuel oil delivery truck pump system is shown in 'FIG. 2. When the truck driver arrives at a customers house, before he gets out of the cab he puts the pump ill in gear and lets the truck motor run at idling speed. The pump 10, then willbe bypassing at a low pressure.

setting (system pressure about p.s.i.), since as hereinafter described there is no air pressure on the diaphragm 29. The driver pulls a hose 48 from a reel 49 in a low pressure condition. It is preferred that there be a certain minimum pressure always present in the system so that the hose 48 will wind on the reel 49 in an extended condition. A completely flat hose, when wound on a reel, provides a restriction to thefiow on the next usage if the entire'hoseis not removed from the reel. The above minimum pressure is obtained because the regulator spring 39 does not go to a completely relaxed position when air pressure is exhausted from the diaphragm chamber 33. When the driver puts the hoses nozzle 56 in the customers tank, he opens the nozzle 50. Flow of fuel oil through the system is sensed by means of a standard commercial pilot valve 51 which opens an air valve 52 that supplies air under pressure through one end of the tubing to the diaphragm chamber 33 maintaining a high regulated pump output pressure and supplies air under pressure through the other end of the tubing 45 to an air cylinder 53. The air cylinder 53 has a rod 54 which rocks a bell crank 55 clockwise as viewed in FIG. 2 about its pivot 56 when air is supplied to the cylinder 53 to actuate a throttle positioner on the truck motor to speed the motor up to normal pump speed. A return spring 57 returns the bell crank 55 to its position shown in FIG. 2 when air is exhausted from the cylinder 53. When the delivery is complete, the driver closes the nozzle 56 and immediately the truck motor drops back to idle speed and the air is exhausted from the diaphragm chamber 33 allowing the pump 10 to recirculate at low pressure.

The inlet port 12 of the pump 11 communicates through a strainer 58 with a truck fuel oil tank 59 and the outlet port 13 of the pump 11 is attached to a pipe 60 which carries the fuel oil through an air eleminator 61, a meter 7 62 and the pilot valve 51 to a pipe 64 communicating with the hose 48. The air eliminator 61 is provided with a float-operated valve 65 which is mechanically connected to a float 66. At the start, the valve 65 is open exhausting any air under pressure through a vent pipe 67 to the atmosphere. When the fuel oil is pumped through the pipe 60, it rises in the air eliminator 61 and air bubbles on top of the oil break and the air is exhausted to the atmosphere. Eventually, the oil rises to a point Where it lifts the float 66 closing the valve 65. Air-free oil then flows into the meter 62. i

V The pilot valve 51 is a spring loaded poppet type check valve with an extended stem 68, carrying a member 69 which actautes the air valve 52. Being spring loaded by means of a spring 70, the pilot valve 51 provides a back pressure to the meter 62 and the air eliminator 61 which assists in blowing air through the air eliminator vent 6'7. Without the back pressure, after the tank 59 is drained, air tends to run through the meter and the hose. The spring loaded pilot valve provides a barrier 71 for the flow of air forcing it to go through the vent tube 67. Accordingly, the pilot valve 51 serves a double purpose. First, it provides the back pressure to the meter 62 and to the air eliminator 61 and, second,- it operates the air.

yalve 52. Air under pressure is supplied to the air valve 52 from a truck air supply tank 72 through a pressure regulator and filter 73 (prevent moisture and dirt from getting into the air system). The air valve 52 has two outlets, one being a vent pipe '74 open to the atmosphere and one being a pipe 75 communicating with the tubing 45, and one inlet pipe 76 in communication with the truck air supply tank 72. When. there is little or no fuel oil flow through the pilot valve 51, the member 69 closes the inlet pipe 76 and opens the vent pipe 74, and air is exhausted from the tubing 45 through the vent pipe 74. This exhausts air from the diaphragm chamber 33 and from theair cylinder 53. When there is fuel oil flow through the pilot valve 51, the oil pushes back the barrier 71 in opposition to the spring 79 and the member 69 opens the inlet pipe I76and closes the vent pipe 74,

and air is supplied under pressure through the pipe 75 to the tubing 45. This supplies airunder pressure to the diaphragm chamber 33 and to the air cylinder 53.

Flow of fuel oil through the system is sensed by means of the pilot valve 51 which, when there is oil flow, opens the air valve 52 that then supplies air under pressure to the tubing 45, and which, when there is no oil fiow, closes the air valve 52 that then exhausts air from the tubing 45 to the atmosphere (no oil flow condition shown in FIG. 2). The air under pressure is applied through the tubing 45 to the diaphragm chamber 33 forcing the diaphragm 29 and the end of the regulator spring 39 remote from the valve disk 26 to a position fixed by the nuts 41 and 42 on the threaded stem 35 and in this position the regulator spring 39 holds the valve disk 26 closed until the desired high regulated pressure is reached at the pump discharge. If the pressure tends to rise above such regulated pressure, the valve disk 26 lifts sufliciently to bypass the excess fluid flow and maintains the preset pressure (preset by adjustment nut 41). The housing surrounding the valve disk 26 is do designed that little additional pressure is required to hold the valve open for any bypass flow thereby holding a substantially constant maximum pressure when the pump is operating at intermediate flow rates. When the air is released, as a result of the action of the pilot valve 51 sensing a no flow condition in the pipe 60, the diaphragm 29 is allowed to move thus releasing the coil spring 39. The limit of travel of the diaphragm 29 is such that the coil spring 39 is not completely released. In this position with the pump running at idling speed, the bypass valve 26 supplies enough back pressure to overcome the pilot valve back pressure when the nozzle 50 is opened thus providing a pressure drop across the pilot valve 51 to open the pilot valve.

In operation, with the nozzle 50 closed (condition of system as shown in FIG. 2), the pilot valve 51 senses a no oil flow condition, closing the air inlet 76 and opening the air vent 74 of the air valve 52. Air then is exhausted from the diaphragm chamber 33 through the tubing 45, pipe 75 and vent 74 of the air valve 52 to the atmosphere. The release of high pressure air from the diaphragm chamber 33 permits the regulator spring 39 to expand and push the diaphragm 29 away from the valve seat 27, the regulator spring 39 holding the valve disk 26 closed until the desired low pressure is reached at the pump discharge. This low regulated pressure is substantially independent of motor or pump speed (one of the features of the system). If the pressure tends to rise above such low regulated pressure, the valve 26 lifts sufliciently to bypass the excess fluid flow and maintain the preset pressure. When the nozzle 50 is opened, the pilot valve 51 senses oil flow, opening the air inlet 76 and closing the air vent 74 of the air valve 52. Air then is supplied under pressure to the diaphragm chamber 33 from the air valve 52 through the pipe 75 and tubing 45. The air under pressure forces the diaphragm 29 and the end of the regulator spring 39 remote from the valve disk 26 to a position fixed by the nuts 41 and 42 on the threaded stem 35 and in this position the regulator spring 39 holds the valve disk 26 closed until the desired high regulated pressure is reached at the pump discharge. The high regulated pressure is adjusted by turning the nuts 41 and 42.

Accordingly, the air pressure adjusted relief valve of the invention controls the pump 10 and, thus, controls the discharge system, there being in the pump control for the discharge system a pump having inlet and outlet ports, a passage in the pump connecting the ports, valve means in the passage controlling the flow therethrough, and control means responsive to flow in the discharge system for adjusting the valve means by air pressure to produce, when no flow exists in the discharge system, a low regulated pressure in the outlet port which is substantially independent of pump speed and to produce, when flow exists in the discharge system, a regulated pressure in the out let port which is higher than said low regulated pressure.

It is to be understood that the above description is illustrative of this invention and that various modifications thereof can be utilized without departing from its spirit and scope.

Having described the invention, we claim:

1. A system for supplying liquid selectively at either of two controlled pressures comprising, in combination, a positive displacement pump, a relief valve for bypassing liquid from theoutlet to the inlet side of the pump to limit the pressure on the outlet side, a spring having one end engaging the relief valve to bias the valve toward closed position, an abutment which supports the other end of the spring and which is movable to change the closing bias of the valve, a line leading from the outlet side of the pump which contains, in succession, an air eliminator, a meter and a valve for sensing flow which is biased toward closed position and is opened by flow of liquid, and means actuated by the flow-sensing valve for positioning the abutment to reduce the closing bias of the relief valve when the flow of liquid in the line is reduced.

2. A system for supplying liquid selectively at either of two controlled pressures comprising, in combination, a positive displacement pump, a relief valve for bypassing liquid from the outlet to the inlet side of the pump to limit the pressure on the outlet side, a spring having one end engaging the relief valve to bias the valve toward closed position, a chamber having a wall which supports the other end of the spring and which is expansible to change the closing bias of the valve, a fluid pressure-actuated control for regulating the speed of the pump, means for supplying fluid under pressure to the chamber and to the fluid pressure-actuated control, means for sensing flow of liquid in the system, and means actuated by the sensing means for changing the pressure of the fluid supplied to the chamber and to the fluid pressure-actuated control to reduce the closing bias of the valve and the speed of the pump when the flow of liquid supplied by the system is reduced.

3. A system for supplying liquid selectively at either of two controlled pressures comprising, in combination, a positive displacement pump, a relief valve for bypassing liquid from the outlet to the inlet side of the pump to limit the pressure on the outlet side, a spring having one end engaging the relief valve to bias the valve toward closed position, an abutment which supports the other end of the spring and which is movable to change the closing bias of the relief valve, a second valve which is opened by flow of liquid through the system to sense flow of liquid in the system, and means controlled by the second valve for positioning the abutment to reduce the closing bias of the relief valve when the flow of the liquid supplied by the system is reduced.

4. A system as claimed in claim 3 wherein the abutment which supports an end of the spring is in turn supported by the wall of a chamber which is expansible to change the closing bias of the relief valve, and wherein the means controlled by the second valve positions the abutment by changing the pressure in the chamber.

References Cited by the Examiner UNITED STATES PATENTS 1,367,452 2/21 Bolton. 1,579,940 4/26 Iversen. 1,935,544 11/33 Delancey 103-42 2,160,028 5/39 Moore 103-42 2,280,291 4/42 Jaseph 103-42 2,364,489 12/44 Taylor 103-42 2,409,975 10/46 Curtis 103-42 2,521,270 9/50 Vanni 103-42 2,625,108 1/53 Logan 103-42 2,671,409 3/54 Wright 103-42 2,683,418 7/54 Smith 103-42 2,747,598 5/56 Wooldridge 103-42 (Other references on following page) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,183,839 May 18, 1965 Virgil A. Brunson et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, line 2, for "a company of Michigan," read assignors, by mesne assignments, to Dover Corporation of New York, N. Y., a corporation of Delaware, line 11, for "Virgil A. Brunson and Harold L. Vanden Hoek, their heirs" read Dover Corporation, its successors in the heading to the printed specification, lines 4 and 5, for "assignors to Blackmer Pump Company, Grand Rapids, Mich., a company of Michigan" read assignors, by mesne assignments, to Dover Corporation, New York, N. Y. a corporation of Delaware column 2, lines 20 and 21, for "cylidrical" read cylindrical column 3, line 68, for "Anather" read Another column 4, line 35, for "eleminator" read eliminator line 48, for "actautes" read actuates column 5, line 21, for

"do" read so Signed and sealed this 26th day of April 1966.

(SEAL) Attest:

ERNEST ;W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

2. A SYSTEM FOR SUPPLYING LIQUID SELECTIVELY AT EITHER OF TWO CONTROLLED PRESSURES COMPRISING, IN COMBINATION, A POSITIVE DISPLACEMENT PUMP, A RELIEF VALVE FOR BYPASSING LIQUID FROM THE OUTLET TO THE INLET SIDE OF THE PUMP OF LIMIT THE PRESSURE ON THE OUTLET SIDE, A SPRING HAVING ONE END ENGAGING THE RELIEF VALVE TO BIAS THE VALVE TOWARD CLOSED POSITION, A CHAMBER HAVING A WALL WHICH SUPPORTS THE OTHER END OF THE SPRING AND WHICH IS EXPANSIBLE TO CHANGE THE CLOSING BIAS OF THE VALVE, A FLUID PRESSURE-ACTUATED CONTROL FOR REGULATING THE SPEED OF PUMP, MEANS FOR SUPPLYING FLUID UNDER PRESSURE TO THE CHAMBER AND TO THE FLUID PRESSURE-ACTUATED CONTROL, MEANS FOR SENSING FLOW OF LIQUID IN THE SYSTEM, AND MEANS ACTUATED BY THE SENSING MEANS FOR CHANGING THE PRESSURE OF THE FLUID SUPPLIED TO THE CHAMBER AND TO THE FLUID PRESSURE-ACTUATED CONTROL TO REDUCE THE CLOSING BIAS OF THE VALVE AND THE SPEED OF THE PUMP WHEN THE FLOW OF LIQUID SUPPLIED BY THE SYSTEM IS REDUCED.