US3361072A - Duplex pump - Google Patents

Description

Jan. 2, 1968 w. H. TUNGATE ET AL DUPLEX PUMP 6 Sheets-Sheet 1 Filed Sept. 6, 1966 Irma/5V5 Jan. 2,1968 w. H.-TUNGATE ETAL I 3,

I I DUPLEX PUMP Filed Sept. 6, 1966 6 Sheets-Sheet 2 INVENTORS .W/LL/AM H- Til/V ATA' HAROLD 4. BEN LEV Arron/EV? w. H. T NGATE ETAL' 3,361,072

Jan. 2, 19 's- DUPLEX PUMP 6 Sheets-Sheet 4 Filed Sept 6, 1966 TM 0V 5 VIM m F A M Jan. 2, 1968 w. H. TUNGATE ETAL 3,351,072

- I V DUPLEX PUMP I Filed Sept. 6, 1966 6 S heets-Shet 5 INVENTOR wax/4x1 70/1/6475 #IGOLD 14- 55/1/7115) ma aim Z4.

ATTOE/VEVS Jan. 2,1968 W.H.TUNGATE ETAL 3,361,072

DUPLEX PUMP Filed Sept, 6, 1966 e SheetsSheet s 1 INVENTORS W/ZZ/A/V 4 77/11 6472" 5 MGULD 4 56/1/7257 United States Patent Filed Sept. 6, 1966, Ser. No. 577,257 8 Claims. (Cl. 103-106) This invention relates to pumps and more particularly to a type thereof primarily adapted for use on a fire truck. In providing pumps, including multistage pumps, for use on and with vehicles such as fire trucks, there has been a continuing problem of finding sufficient space within the truck structure for the reception of a pump mechanism capable of carrying out the functions required therefrom. These problems have grown out of several considerations. In the first place, because of mechanical considerations, it is desirable to mount the pump for driving from the propeller shaft of the truck, for example, it is convenient to locate the power take-off for the pump ahead of the universal joint of the propeller shaft. Further, to simplify the necessary gearing, it is desirable that the axis of the pump rotary structure be parallel to the axis of the propeller shaft. The former of these considerations require that the pump be placed close to the transmission of the vehicle which, in a tilt-cab vehicle, means that serious problems of space are encountered when the pump is made of size large enough to have a capacity commensurate with pumping requirements and available power from the vehicles engine. These problems are further aggravated by the positioning of the rotary pump means parallel with the propeller shaft of the vehicle and still further aggravated by the center intake type of pumps commonly used in this location. If the conduits leading to said center intakes are bent through a sharp angle, there is an excessive loss of power due to liquid friction developing at such bend. On the other hand, if said intake conduits are provided with longer and more gentle curves, then the total length of the pumping equipment is excessively extended and still further limits the size of pumping equipment which can be accommodated in the space normally available between the vehicle transmission and its universal joint.

Thus the objects of the invention are:

(1) To provide a pump design for use on pumping vehicles, particularly fire trucks, which will permit a substantially greater pumping capacity per unit of axial length than is currently available from conventional equipment.

(2) To provide pumping means as aforesaid which will permit the pump to be positioned between the transmission and the universal joint of a motor-driven vehicle and still have said pump be of sulficiently large capacity to utilize efiiciently the power available from the power plant of the vehicle.

(3) To provide a pumping device as aforesaid whose rotary means are parallel to the propeller shaft of the vehicle but wherein the axially extending conduits normally required for end-suction pumps are eliminated and the suction side of the pumping equipment is provided by conduit means arranged tangentially.

(4) To provide pumping equipment'as aforesaid utilizing both a capacity pump and a pressure pump and having valve means for efficiently and effectively obtaining cooperative action therebetween.

(5) To provide pumping means as aforesaid capable of easy and efficient maintenance and particularly including suction box means capable of easy access and convenient replacement of packing.

(6) To provide pumping equipment as aforesaid minimizing the frictional resistance to fluid flow on the inlet 3,361,072 Patented Jan. 2, 1968 ice side of the pump and thereby minimizing the size of conduit required for supplying fluid thereto.

(7) To provide pumping means as aforesaid which is of suificiently simple design as to be capable of eoonornical manufacture and of inexpensive and eifective maintenance.

Other objects and purposes of the invention will be apparent to persons acquainted with this general type of equipment upon examination of the following specification and the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevational view of a pump assembly embodying my invention, the engine of a motor vehicle being conventionally illustrated and wheels of the vehicle also being conventionally illustrated.

FIGURE 2 is a top or plan view of the pump assembly on a line corresponding to line II-II of FIGURE 1, parts of the conduits being broken away.

FIGURE 3 is a fragmentary view partially in vertical section on a line corresponding to line III-III of FIG- URE 2 but with the portion within the broken lines A taken on the line IIIAI IIA of FIGURE 11.

FIGURE 4 is a fragmentary View in section on a line corresponding to line IV-IV of FIGURE 2.

FIGURE 5 is a fragmentary view in section on a line corresponding to line V-V of FIGURE 2.

FIGURE 6 is a fragmentary view in section on a line corresponding to line VI-VI of FIGURE 2.

FIGURE 7 is an enlarged fragmentary view on a line corresponding to line VII-VII of FIGURE 3, further illustrating details of the pump drive means.

FIGURE 8 is a fragmentary view on a line corresponding to line VHF-VIII of FIGURE 5.

FIGURE 9 is a fragmentary view partially in section on a line corresponding to line R-IX of FIGURE 10 showing a modification of one of the shaft stuffing boxes shown in FIGURE 3.

FIGURE 10 is a fragmentary view, mainly in section, on a line corresponding to line X-X of FIGURE 9.

FIGURE 11 is a fragmentary sectional view on a line corresponding to line XIXI of FIGURE 3.

General description In general the objects and purposes above set forth are met by providing a pumping device driven from the propeller shaft of the motor vehicle wherein is utilized a double-end multistage arrangement which relocates the inlet to the pumps from the axial ends thereof to a position centered on the radial central plane of each pump unit. This materially reduces the amount of axial room required in the truck for a pump of given capacity. This also eliminates sharp bends in the inlet conduit which are characteristic of previously known pumps and makes possible the delivery to the pump of a given quantity of liquid through a conduit of smaller diameter than was considered necessary in previous practice.

A further feature of the invention contemplates a manually actuated valve arranged so as to place the outputs of the capacity pump and the pressure pump in either series or parallel alignment and thereby increase flexibility of capacity and/or pressure of characteristics in the liquid output over those obtainable in previous practice. A still further feature of the invention particularly contributing to the easy but effective maintenance of the equipment is the provision of a stufiing box for the pump by which the packing for the pump can be readily and efficiently added while the pump is operating.

Detailed description Referring now to the drawings in detail, there is shown somewhat diagrammatically in FIGURE 1 an arrangement of the pump of the invention in association with a vehicle power system. In the drawings there is shown a vehicle power plant 1 in association with a transmission 2 driving an output shaft 3. Said output shaft 3 drives through the input shaft 4 of the pump unit 5 and thence drives through a propeller shaft 6 to the differential 7. Wheels are indicated at 8 and 9 and a conventional tilttype cab is indicated at 11 Giving closer attention now to the pump structure and with particular attention to FIGURE 3, the pump driving shaft 4 is mounted in bearings 11 and 12 and drives the power input gear 13. This gear meshes with an idler gear 14, the same being mounted by any conventional bearing means not shown. Said idler gear in turn drives pump input gears 16 and 17. This idler 14 is slideable by a shift fork (not shown) acting at the collar 14A to drive either or both of the gears 16 and 17 as desired. Gear 16 is drivingly mounted on a shaft 18 which is in turn mounted for rotation in bearings 19 and 21, said shaft 18 extending through a packing gland 22, which in this embodiment is shown in conventional form and rotatably and drivingly supports a pump rotor 23. Said pump rotor is of conventional form having passageways at each end thereof, of which one is indicated at 24, extending from a zone near the center thereof radially outwardly to discharge at 26 into an output conduit 27.

The gear 17 above mentioned is rotatably and drivingly mounted on a shaft 31 which is suitably supported in bearings (not shown) but generally similar to the bearings 19 and 21, said shaft extending through a packing gland 32, which is here shown as of conventional form, and drivingly supports the rotor 30. Said rotor 33 has passageways at each end thereof, of which one is indicated at 34, extending from a zone near the hub thereof radially outwardly to discharge into a discharge passageway 36.

An inlet housing 37 is provided as convenient with extension conduits 38 and 39 as seen in FIGURE 2 for projection to or through the side of the fire truck, said extension conduits being normally capped as indicated at 41 and 42 but either of said caps may be removed as desired and a supply conduit such as a fire hose connected in place of either thereof.

The inlet housing 37 (FIGURE 5) communicates through a port 46 and a flapper valve 45 with a zone 43 immediately thereabove and defined in part by the housing 44. Said housing defines a passageway 46 (FIG- URE 6) communicating with and supplying the inlet chamber 47 which sup-plies the impeller 23 through the passageways 48 and 49 (FIGURE 3). The housing 37 (FIGURE 5) similarly supplies the impeller 33 through the passageways 51 and 52 (FIGURE 3). The discharge chamber 27 (FIGURE 6) of the pump 23 discharges through a conduit 53 and the normally closed gravity valve 54 (FIGURES 4 and 6) into the passageway 56 within a housing 57. From chamber 56 liquid enters into the chamber 58 and thence passes into one of the conduits 59 or 611* (FIGURE 4). Said conduits 53 or 60 may each be capped as indicated by the cap 55 and each thereof is provided with a manually controllable valve of which one appears at 65.

Returning now to the impeller 33 of FIGURE 5, same discharges into the zone 36 and thence into each of the passageways 61 and 62'. Liquid in the passageway 61 enters into the passageway 63 within the housing 64-, thence passes the normally closed gravity valve 66 (FIG- URE 4) and into the above-mentioned chamber 58. Simultaneously the impeller 33 (FIGURE 5) discharges liquid which is impelled into the passageway 62 and in turn goes through the manually operated selector valve 67, when said valve is open, and thence into the abovementioned chamber 43. From said chamber 43 said liquid travels to and through the impeller 23 in the same manner as above outlined and from said impeller by the passageways 53 and 56 to the chamber 58. So long as fluid pressure originates from passageways 53 and 63 both gravity valves remain open, however, if fluid pressure is only originating from passageway 53 then gravity valve 66 closes thereby preventing fluid from passing from chamber 5'8 into passageway 63. The converse is also true, if fluid pressure is only originating from passageway 63 then the appropriate gravity valve is closed preventing from passing from chamber 58 into passageway 53.

Operation This system operates to utilize the impeller 33 for supplying a large volume of low pressure liquid to the chamber 63 and thence through valve 66 and chamber 58 to the outlet conduits 59 or 63 while the impeller 23 provides liquid at a high pressure and low volume to chamber 53 and thence through valve 54 and chamber 58 to the same discharge conduits above mentioned.

Thus, with only the capacity pump running (by appropriate setting of the idler 1d) the selector valve 67 will be either open or closed. If closed, discharge will go out through conduit 63, through valve 66 to the discharge chamber 58. Valve 54 will be held closed by the pressure in said chamber so that liquid will not go back through the high pressure pump 23. If selector valve 67 is open, then pressure can go through same and conduit 46 to and through pump 23 to the valve 54. Under normal conditions, valve 54 will remain closed as above outlined and nothing further will happen. However, if a large demand is made on the capacity pump, or if friction at the valve 66 becomes excessive, flow through valve 54 can occur to supplement flow through valve 66.

With only the pressure pump running, intake will go through port 46 to chamber 43 and passageway 46 to said pressure pump 23. it is immaterial whether the selector valve is open or closed. Discharge from the pressure pump will go out through gravity valve 54 and passageway 56 to the discharge chamber 53. Pressure in chamber 58 will hold valve 66 closed.

With both pumps running, and the selector valve 67 closed, the pumps will operate independently each as above described, and in parallel to a common discharge from chamber 58. That is, liquid enters capacity pump 33 from the intake housing 37 and discharge therefrom, being blocked at valve 67, goes entirely out conduit 61, through valve 66 to the discharge chamber 58. Simultaneously, liquid from the intake housing 37 passes through the port 40 and valve 45 to the conduit 46, thence to the intakes of the high pressure pump 23 and discharge therefrom goes through valve 54 and passageway 54 to the discharge chamber 58. With both pumps running and the valve 67 open, the pressure-holding valve 66 opening will be reduced and same will close in response to pressure in chamber 58. Thus, discharge from the capacity pump will go through passageway 62, through selector valve 67 to chamber 43 to hold flap valve 45 closed and thence to go through passageway 62, through selector valve 67 to chamber 43 to hold flap valve 45 closed and thence to the inlet of pump 23. Discharge from the pressure pump 23 will go as before through valve 54 into chamber 58 and out the pipes 59 or 61. At the same time pressure in chamber 58 holds valve 66 closed. Thus the pumps will operate in series.

By this arrangement, either pump may operate alone, or both may operate together, by the setting of the single means operating the collar 14A to locate idler 14. With both pumps running, they may be made to operate in series or in parallel by the setting of the single valve 67.

Inasmuch as the valve 67 will be subjected to a relatively high pressure it will be desirable to provide both for effective guidance thereof and effective sealing. Several apparatuses are already known to the industry for this purpose and the one shown in FIGURE 5 and further detailed in FIGURE 8 is only indicative of several which might be used. In the particular embodiment shown the valve is placed within the end 44A of the housing 44 and contains an internal valve guide 71, the same being held in place by the nut 72. The valve stem 73 extends through a packing gland 74, which in this instance is of conventional construction and supports the valve body 76. Said valve body has suitable openings therein of which one is indicated at 77 and a downwardly directed opening 78 communicating with passageway 62 (FIGURE 5). Openings 79 and 80 (FIGURES 5 and 8) are provided in the valve guide 71 in a conventional manner for providing communication between the passageway 62 and the chamber 43 upon appropriate setting of the valve body 76 with the valve guide 71.

Turning now to FIGURES 9 and there is shown an arrangement for supplying a packing gland in place of the gland units 22 and 32 of FIGURE 3. Taking the packing gland 32 as an example, the structure immediately surrounding same is shown in FIGURE 9 together with the shaft 31, the stufiing box structure being provided by the projecting flange 81 defining a stufiing box $2. The improved packing gland 83 discloses a stuffing box in a conventional manner and a gland is fixed snugly thereagainst in a convenient manner such as by screws of which one appears at 84. Note that said gland is fixed rigidly in place instead of being adjustable into said stuffing box in a more conventional manner and as indicated by the corresponding stufiing box shown in FIGURE 3.

Communicating with this stuffing box, however, either directly as shown or through the gland, there is provided a sidewardly opening passageway 86 of any desired, here circular, cross section (as shown in FIGURE 9), sensed preferably in the direction of rotation of the shaft. A threaded nipple 87 extends outwardly from the outer end of said passageway and an adjustable cap 88 is threaded onto said nipple. Soft plastic packing material is filled into the space 89 within said passage 86 and by screwing said cap down onto said nipple 87 packing material is forced into the stuffing box 82. If desired, a plunger 90 may be used to apply pressure from the cap to the packing. By introducing said packing material at, or close to, one end of the stuffing box, the packing material is caused to fill the entire stuffing box and as same wears it is readily renewed by a simple further rotation of the cap 88. Thus the stufiing box is kept perpetually filled under whatever packing pressure is desired by means externally accessible, and operable while the equipment is operating, which contrasts favorably with a much more difficult procedure of reaching the glands of the conventional stutfing boxes 22 and 32 of FIGURE 3 and tightening them in the more conventional manner.

Although a particular preferred embodiment of the invention has been disclosed above in detail for illustrative purposes, it will be recognized that variations or modifications of such disclosure, which come within the scope of the appended claims, are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a liquid pressure creating means for use in combination with a motor vehicle, particularly a fire truck, the combination comprising:

a power input shaft driveable from the transmission of said vehicle;

first and second impellers arranged for rotation on axes parallel with the axis of said input shaft;

shaft means for driving said impellers;

gear train means driveable by said input shaft for driving said shaft means;

a housing defining a first inlet passageway substantially parallel to the radial plane of said first impeller and means for providing Zones of said inlet constituting communication from said inlet to the suction sides of said first impeller;

means defining first and second discharge means for said first impeller;

a second inlet passageway means connecting said first discharge means to the suction side of said second impeller, said second inlet passageway means approaching said second impeller in a manner so as to be substantially parallel to the central radial plane of said impeller;

conduits connecting the discharge of said second impeller and said second discharge means of the said first impeller to a common chamber and discharge conducting means connected to said common chamber;

means preventing back-flow from said common chamber to said second discharge means.

2. The device defined in claim 1 including selector valve means in the passageway connecting said first discharge means to the suction supply of said second impeller;

means connecting said inlet passageway to the suction side of said second pump and means closing said last-named means when said selector valve is open.

3. The device defined in claim 1 wherein said shaft means comprises two separate shafts parallel and offset with respect to each other, each rotatably supporting one of said impellers and each in parallel with said input shaft.

4. The device defined in claim 1 including separate pinions of each of said shafts, said gear train being arranged to simultaneously drive both or a selected one of said pinions,

5. The device defined in claim 1 wherein the impellers rotate in parallel planes and the inlets to each of said impellers are each bisected by the central radial planes of each respective impeller.

6. The device defined in claim 1 including stufiing boxes through which said shaft means extend, said stuffing boxes having gland means rigidly afiixed thereto and means defining a storage passageway to said stuffing box;

pressure means for impelling plastic packing through said storage passageway and into said stuifing box, pressure means for creating pressure on plastic within said storage passageway.

7. The device of claim 6 wherein said pressure means includes a plunger within said storage passageway and manually controllable means for applying pressure to said plunger.

8. The device of claim 1 wherein each of said impellers is a double suction impeller and said inlet passageways each substantially straddles said impellers.

References Cited UNITED STATES PATENTS 2,112,651 3/1938 Fox 103-106 2,422,415 6/1947 Howe et al. 103--106 2,780,998 2/1957 Cilker 103-106 2,995,092 8/1961 Thomas etal 103106 3,110,264 11/1963 Smith 103106 HENRY F. RADUAZO, Primary Examiner.

Claims (1)

1. IN A LIQUID PRESSURE CREATING MEANS FOR USE IN COMBINATION WITH A MOTOR VEHICLE, PARTICULARLY A FIRE TRUCK, THE COMBINATION COMPRISING: A POWER INPUT SHAFT DRIVEABLE FROM THE TRANSMISSION OF SAID VEHICLE; FIRST AND SECOND IMPELLERS ARRANGED FOR ROTATION ON AXES PARALLEL WITH THE AXIS OF SAID INPUT SHAFT; SHAFT MEANS FOR DRIVING SAID IMPELLERS; GEAR TRAIN MEANS DRIVEABLE BY SAID INPUT SHAFT FOR DRIVING SAID SHAFT MEANS; A HOUSING DEFINING A FIRST INLET PASSAGEWAY SUBSTANTIALLY PARALLEL TO THE RADIAL PLANE OF SAID FIRST IMPELLER AND MEANS FOR PROVIDING ZONES OF SAID INLET CONSTITUTING COMMUNICATION FROM SAID INLET TO THE SUCTION SIDES OF SAID FIRST IMPELLER; MEANS DEFINING FIRST AND SECOND DISCHARGE MEANS FOR SAID FIRST IMPELLER; A SECOND INLET PASSAGEWAY MEANS CONNECTING SAID FIRST DISCHARGE MEANS TO THE SUCTION SIDE OF SAID SECOND IMPELLER, SAID SECOND INLET PASSAGEWAY MEANS APPROACHING SAID SECOND IMPELLER IN A MANNER SO AS TO BE SUBSTANTIALLY PARALLEL TO THE CENTRAL RADIAL PLANE OF SAID IMPELLER; CONDUITS CONNECTING THE DISCHARGE OF SAID SECOND IMPELLER AND SAID SECOND DISCHARGE MEANS OF THE SAID FIRST IMPELLER TO A COMMON CHAMBER AND DISCHARGE CONDUCTING MEANS CONNECTED TO SAID COMMON CHAMBER; MEANS PREVENTING BACK-FLOW FROM SAID COMMON CHAMBER TO SAID SECOND DISCHARGE MEANS.

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