US 2160735 A
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Description (OCR text may contain errors)
May 30, 1939. J, F HQFFER 2,160,735
METERING PUMP Filed May 29, 1935 n 3 Sheets-Sheet 1 May 30, 1939. J. HoFFr-:Rv
METERING PUMP 3 Sheets-Sheet` 2 Fiied May .29, 1955 hm. @u @www cfa/7296 539566124 Mob' May 30, .1939. J. F. HOFFER 2,150,735
METERING PUMP Filed May' 29, 1935 3 sheets-sheet 5 Innen/071 Patented May 30, 19,39
UNITED STATES PATENT ortica METERING IUlll y James Frlloer, Detroit, Mich., .to Fk- Cell-O Corporation, a corporation of Michigan Appiicauon May 29, 1935. sei-n1 No. asma w s claims. (o1. 12s-1:9)
metering pump, having, a pluralityof plungerand cylinder units, with'novel means, other than normally rotating*V or sliding separate valve members, for admitting limited amounts of fluid or liquid fuel to each of the pump cylinders, thereby avoiding to a substantial extent the use of rapidly Imoving bearing surfaces subject to wear in the presence of minute particles of dirt and other foreign matter likely to be present-in liquid fuel.
A further object resides in the provision'of a novel plunger-pump in which the means for admittingthefuel to the various cylinders is effective tothrottle the fuel and/orA to impart a swirling motion thereto so as to obtain a uniform distribution regardless of the innuence of gravity. ow surges in the fuel supply, and 'other factors.
Other objects reside in providing the means for throttling the incoming fuel in the form lof a z5 manually adjustable valvewhich is adapted to control the throttle action and hence the delivery of the pump. which is not inuenced by fuel pressures,injection impulses or springs, and which sets up a minimum of mechanical resistance to adjustxient without being subject to self-adjust- Another object isy to provide anew and improved plunger pump inwhich the quantity of fuel discharged in each plunger stroke for a given throttle adjustment automaticallyvaries inversely with the speed of the pump, andthe engine speed, and whichv therefore has inherent governing or self-compensating characteristics eiective to stabilize the engine speed.
A more specinc object resides in the provision of a multiple plunger pump in whichth'e pump cylinders and plungers constitute novel inlet valve means adjustable atwill vto change the phase s relation of each injection period to the pump drive. v
Still anotherobject is to provide a pump of the foregoing character in which the pump plunger-s are rotatably adjustable to vary the timing of fuel discharge, and which'comprises novel means,
including a single manually operable control member, for adjusting all ofthe plungers simultaneously and equally.
A general object is to provide a new and improved metering pump which is satisfactory for 'form of the pump.
highly volatile fuels, such as naphthaand gasoline, and also for heavier fuel oils. Y
Further objects and advantages will become apparent as the description proceeds.
, In the accompanying drawings, Fig. 1 is a per- 5 spective view of a pump embodying the features of my invention.
Eig. 2 is afragmentary longitudinal sectional view of the pumptaken substantially along line 2-2 oi 1'. 10 Fig. 3 is a transverse sectional viewtaken along line 3-3 of Fig. 2.
Fig. 4 is a fragmentary sectional view taken along line I--4 of Fig. 3.
Fig. 5 is a longitudinal sectional view of the 16 pump taken substantially along line 15-5 lof Fig. 1. Fig. 6 is a transverse sectional view taken substantially along lineB-S of Fig. 5. l
Fig. 7 is a fragmentary sectional view taken in the same plane as Fig. 5, and illustrating a modi- '20 ned'form of the pump. i A f Fig.8 is a perspective view of another modified Fig. 9 is a .fragmentary longitudinal sectional view taken substantially along line 9 -9 of 8. g5
Fig.- 10 is a transverse sectional view taken substantially along line II-l of Fig. 9. While the invention is susceptible oi various modications and alternative constructions,A I have shown in the drawings and will herein -de- 30 scribe in detail, the preferred embodiment. but it is to be understood that I do not thereby intend to limit the invention to the specic form disclosed,
- but intend to cover all modifications and alterna-V tive constructions falling within 'the spirit and 35 scope of the invention as in the appended claims.
'Referring more particularly to the drawings,
' the pump constituting the preferred embodiment of the invention comprises a body Il which pref- 4 erably is cylindrical in `form, and which has a plurality of longitudinal pump cylinders Il to II.
In the present instance, the cylinders Il to I6 are annularly arranged in parallel uniformly spaced-relation 'about the axis of the body It. 45
Mounted respectively for reciprocation in the cylinders H to It are a plurality of pump plungers H to 22.
The cylinderbody Il maybesupportedinanv Y suitable manner, and in thepresent instance is 5o formed at one end with a peripheralflange 23 secured by means ot a clamp nut 2l against an annular shoulder 25 within one end of an elongated drive housing 2i to which .the pump cylin` dersll tollopen. Thehousingpreferablyis 55 I t generally cylindrical in shape, and is formed inl the end adjacent the body I8 with a relieved cylindrical bore 21 and with an' internal annular flange 28 defining a shoulder at the inner end of the bore. Seated in the inner end of the bore 21 against the ange 28 and extending through the latter is a guide block 2i)l formed with a plurality of parallel annularly arranged bores 38 opening therethrough, andrespectively in spaced axial alignment with the pump cylinders to I6. A sleeve 3| is fitted snugly in the bore 21 and in end engagement with the cylinder body I8l and the block 29, and has an end wall 32 seating against the inner face of the body andformed with an-l nularly arranged circular openings 33 in full xl'gistrastion with the open ends of the cylinders to I The pump plungers I1 to 22 are provided respectively with axial rod extensions 34 which project from the cylinders to |5.through the openings 33 into the sleeve 3|. and are therein urged outwardly by spring pressure. Thus, a coiled compression spring 35 encircles each plunger extension 34, and abuts at its ends respectively against the wall 32 and an annular seat 36 on the free end of the extension. Preferably, the spring seat 36 engages in a peripheral groove 31, and is held against a head 38 on the end of the extension 34 by the pressure of the spring 35. 'I'he heads '36 are engaged respectively by a plurality of actuating plungers 39 reciprocable in and extending through the bores 38. It willbe evident that the plungers 39 in effect constitute axial continuations of pump plungers I1 to 22. y
To provide means for reciprocating the plungers I1 to 22 in uniformly timed sequence and preferably harmonically, the outer ends of the actuating plungers 39 are operatively associated with a power driven wobble member or swash plate 48 (see Fig. 5) 'I'he latter is shown in the form of a disk which has a at annular inclined bearing surface 4|, and which is rigid with one end of a sleeve 42 keyed on a drive shaft 43. The other end of the sleeve 42 is formed with a periph- 'eral flange 44, and bears against a transverse wall 45 in the housing 28. An intermediate bearing 46 for the shaft 43 is formed in the wall 45. The inner end of the shaft 43 extends through the sleeve 42 and is rotatably supported in an axial bore 41 in the guidevblock 29. Slidably disposed against the surface 4| is a flat annular floating thrust disk or plate 48 encircling the shaft 43. An angular notch 49 is formed in one side of the shaft 43 to provide clearance for the disk 43. A plurality of oating shoes 58, preferably circular in form, are slidably disposed against the exposed face of the disk 48, and are formed with semi-cylindrical sockets 5| in universal bearing engagement with similarly shaped heads 52 on the adjacent ends of the plungers or tappets 38. The free ends of the shoes 58 are notchedperipherally to define reduced portions 53 which project with a loose nt through openings 54 in an annular retainer 55 suitably secured to the thrust disk.48. In the present instance, the retainer 55 is formed with an annular flange 56 which is spun at its free edge into a notch 51 in the periphery of the disk 48. Thus, the disk 48 and the retainer I55 constitute a cage for the shoes 58.
'I'he outer end'of the shaft '43 projects through `a bearing 58 and an oil seal 58 in one end of the housing 26, and has a coupling or driving gear 59 secured thereto for connection to a suitable source of power (not shown). When the pump is used for injection purposes, the housing 25 is mounted a series of inlet ports 8| to 66 respectively to the pump cylinders to |6 and under the control of the pump plungers I1 to 22. The chamber 68 is .connected through a passage 61 (see Figs. 3 and 4) to a conduit 61Il leading to a suitable source of fluid under a low pressure. In the two forms of Figs. 1 to 7, the conduit/61* leads to a ltering reservoir 68 mounted on the housing 26, and connected through a conduit 69 toa feed pump 18. If desired, the pump 18 may also be mounted on the housing 26, and may be driven by the shaft 43. In the present instance,l the pump 18 (see Fig. 5) is shown with an operating plunger 1| urged by a spring 12 into engagement with an eccentric or cam portion 13 on the shaft 43 intermediate the bearings 46 and 58.
Preferably, the ports 5| to 66 open to the chamber 68 tangentially with respect thereto so that the fluid in passing through the chamber is given a rotary swirling motion about the chamber 68 tending to effect a uniform distribution of fluid throughout the chamber and to the series of ports 6| to 66. That is, theA fluid flowing under pressure from the chamber 58 into the ports 6| to 66 moves into the tangentially arranged ports in paths substantially tangential to the periphery of the chamber 68 and consequently, the fluid in the chamber 68 is given a rotary swirling motion as it moves into this series of ports. Disposed in thel chamber 68 is a plug 14 having a peripheral area or face 15 of reduced diameter extending in spaced relation across the inlet openings of the ports 5| to 55. This plug limits the volume of fluid in the chamber 88, and constitutes a throttling member, and hence serves to impart a high velocity to the fluid passing through the chamber and a greater swirling action than would be obtained by reason of the tangential arrangement of the ports 6I to 66 alone.
, Suitable valve'means may be provided for controlling the supply of uid to the pump. Preferably, the plug 14 serves as such valve means. To this end, the surface 15 is conical in form, and the plug 14 is axially adjustable to vary the effective inlet areas of the portsy 6| vto 66. Since the chamber 68 is always 'filled with fluid under a relatively in the chamber, and the influence of gravity on the fluid when the pump is mounted in a horizontal position.
To provide suitable means for adjusting the throttle 15 axially, a collar 11 (see Figs. 2 and 3), formed in one side with a socket 18, is secured to the outer end of the plug 14 within a chamber 19 defined by an end enlargement of the bore 68. A rock shaft 88, peripherally splined for rotation in a xed axial position, extends through a transverse bore 8| in the body I8 into the chamber 19, and carries an eccentrically l'ocated end face crank pin 82 in engagement with the socket 18. A lever 83 is secured to the outer end of the shaft 88, and is adapted to be connected through a rod 84 to a suitable actuator or control (not shown).
Communication of the ports 8| to 86 with the 'respective cylinders to I8 is controlled by the plungers I1 to 22.' Thus, each of thel pump -plungers is formed with a peripheral groove 85 opening through an axial bore 86 'to the closed end of the associated cylinder, and defining a land area 81 with controlling edges 81EL and 81h.
It will be evident that for each plunger, the cory responding edge 81 controls the point of cut-oil of the associated inlet port, and the edge 81h controls the end ofthe pressure impulse by reestablishing .communication of the port with the' Y to |00 which may lead to some remote point of delivery. for example the cylinders of an internal combustion engine(not shown). It will be evident that the fluid delivered to the conduits 95 to ishandled directly by the plungers I1 to 22.
Referring for purposes of illustration to the plunger I1, when the latter is in the' position shown in Figs. and 6 and the throttle 15 is in wide open position. fluid vwill pass with a limited restriction from the chamber 80 through the po'rt 8| into the cylinder When in the pressure stroke, the edge 81* passes the .port 8|, the
fluid in the cylinder will be compressed and will be discharged through the outlet passage 88, .the valve 94 and. the conduit 95 for injection at the point of delivery. Injection will continueas long as the port 6I is closed by the land area 81.
When the edge 81 passes over the port 6|, the
pressure in the cylinder II will be vented or relieved through the bore I8, the groove 85 and the port back to thechamber 80, and hence the continued movement of the plunger I6 will be ineffective. On the return stroke ofthe plunger I1,
a partial vacuumwill be created in the cylinder lII until the edge 81* again movesover the port 8|, and thereupon the cylinder wil1)be fully charged with a fresh .supply of uid.
When the throttle is partially closed, enough time is not available, due to the reduced rate of flow of the viluid, to charge the cylinder fully,-
and hence the vacuum created in the suction stroke will not be entirely destroyed by the time the land 81 again closes the port 6I.' Injection will not start until the plunger I8 has traveled sufliciently beyond this position to relieve the vacuum and build up a pressure in excess of the seating pressure of the valve 94.
It-will therefore be evident that the start of injection' is governed by the amount of vfuel supplied to the cylinder II, and', since the latter is dependent on the rate o f fluid flow through the port 8| and the time that the port is uncovered by the ,land 81 at the end ofthe return stroke and start .of the pressurestroke, is'dIvarlable in accordance with the setting of the throttle 15 and ,the speed of the shaft 43. In other words, as
the quantity of injection increases, the timing of ,the start of 'injection is automatically advanced.
If the speed of the-engine, and the shaft 43 driven therefrom, increases, for example because of a diminished load, the inlet ports .II' to i6 will be open for a shorter period of time so that a smaller amount of fuel will be injected', thereby "causing the speed to be decreased. Conversely, if the speed of the engine decreases. the inlet given speed and valve setting, a constant start of injection. Fig. 5 illustrates a modified form in which the start and end of mjection, for a given speed and valve setting, are adjustable to change the phasel relation ofthe period of injection to the rotation of the shaft 43.' In this form, the controlling edges `81l and 81 have a lead longitudinaiiy of the plungers I1 to 22, and more particularly are inclined to the plunger axes as indicated at |02, so that upon rotary adjustment -of the plungers the points at which the ports 6| to'68 will be covered and uncovered will be' advanced or retarded in relation to the reciprocation of the plungers.
To providemeans for eifecting this phase adjustment, the plunger extensions 34 are provided intermediate their ends respectively with elongated pinions |03 which mesh with a central spur gear |04. AThe length oi' the gear teeth issuch that the pinions |03 can be reciprocated with the plungers I1 to 22 without interrupting the meshing engagement. The gear |04 is mounted for rotation on the axis ofthe body I0, and is confined against endwise movement between the body and the end wall 32 of the sleeve 3|. Preferably, the gear |04 has a cylindrical hub |05 journaled ai: one end in an inner end enlargement |06 of the bore 60, and at the other end 'in a bearing |01 in y the wall 32.
The gear hub |05 is formed with anY axial bore |08 closed at one end and @opening at the other end to the interior of the; sleeve 3|, and with ldiametrically spaced longitudinal slots |09 opening through the peripheral. wall of the bore. A driving member or shank |I0 extends slidably into the bore |08, and is connected for rotation with the gear |04 by a transverse pin III projecting at opposite ends into the slots |09. A coiled compression spring |I2 abuts atits ends respectively against the innerend of the bore |08 and within an axial recess ||3 in the member I I0, and normally serves to hold the pin II| against the outer ends of the slots |09.
The outerend of the member ||0 is formed with a longitudinal tongue II4-extending slidably into a longitudinal diametrical slot ||5 in the end ofan aligned shaft II4. The latter is mounted for axial fand rotary adjustment in a stationary bearing sleeve II1 which is coniined between a shoulder I I8 in the bore 41 and the adjacent end o f the shaft 43, and which has a reduced portion extending into an axial bore II! in the adjacent end of the shaft 43. The inner end portion of' the shaft I I8 extends from the sleeve I I1 partially into a reduced inner extension ofthe bore |I9, and is formed in opposite sides with helical grooves of opposite leads. Two pins I2I project from opposite sides of the grooves |20.
Axially confined butmtatably movable on the shaft H8 intermediate the ends is acollarj|22 formed in one side with a socket |23. .A rock shaft |24 (see Fig. 2) .journaled in a transverse bore |28 in the housing 24 and the block 29 has an eccentric pin |28 on one .end e in the socket |23, and has a lever |21 on vits'outer end sleeve I|1 into the adapted to be connected through a rod |26 to a suitable actuator or control (not shown). It. will be evident that upon axial adjustment, the shaft ||6 will be caused to rotate by reason of the helical groove and pin splines |26, |2I, and hence through the member and the gears |04 and |03 will effect a simultaneous rotary setting of all the pump plungers |1 to 22 in the desired position of adjustment.
Mounted on .the housing 26 is a governor |63 which is not disclosed in detail since it forms no part of the present invention and which may be connected by means (not shown) to the lever 63 for controlling thethrottle 15. The governor |63 is driven in timed relation to the pump by a shaft |64 connected through bevel gears |65 and |66 Vto the flange 44 keyed on the pump drive shaft 43. When the governor |63 is connected to the lever 63, the throttle 15 will be adjusted to reduce the supply of fluid .upon an increase in pump speed and vice versa.
A modified form of pump, particularly adapted to handle highly volatile fuels and such fuels as contain chemical impurities o r abrasive particles,
is illustrated in Figs. 8 to 10. This pump is generally similar to the one shown in Fig.. 5, and like parts thereof are therefore designated by the same reference characters. In this form, the plungers |1 to 22 acty on Va sealed body f" fluid, such for example as a clean lubricating oil, which is not discharged to the point of pump delivery as in Figs. 5 andY 7, but which serves to transmit actuating pressure impulses to a plurality of indivldual 'injection pump units. Preferably, these pump units are of the diaphragm type, and comprise a plurality of small circular and annularly arranged diaphragm chambers |29 to |34 in an auxiliary pump body bolted to the free end of the body ||l. An annular member |36 of a suitable ilexible material is securely clamped between the pump bodies I0 and |35, and is exposed in the various chambers |29 to |34 to define a series of circular diaphragms |31 to 142. These diaphragms are positioned respectively over the discharge passages 86 to 93, and constitute pumping elements operable'by fluid pressure impulses from the cylinders to I6. Each diaphragm at the end of its suction stroke tends to lie flush against the outer lend face of the pump body lll, and when subjected to a pressure impulse is movable in Va pressure stroke into the associated chamber. a
'I'he fuel to be pumped is adapted to be supl plied at a low pressure from a filtering reservoir |43 on the housing 26, through a conduit |44 to a closed central chamber |45 in the body |35. A feed pump |46 connected through a conduitr |41 to the reservoir |43 serves to maintain the supply of fuel therein. Opening from the chamber |45 respectively to the pump chambers |29 to |34 are a plurality of inletpassages |43 to |53 including individual check valves |54. The pump chambers |29 to |34 open respectively through check valves to a plurality'of discharge conduits |56 to |6| leading to the point of pump delivery (not shown).
Since the fluid' in the pump cylinders to I6 is not discharged but can be used over and over, it is confined within a. closed system. Tol this end, theinletlconduit 61* is connected to a sealed reservoir |62 which is mounted on the housing 26 andwhichservestomaintain the chamber flooded.
In operation, the pump plungers I1 to 22 oper- 761 ate in the same manner as in Figs. 5 or '1. Considering the plunger |1, on each pressure stroke,
the duid in the cylinder is placed under pressure, and surges through the passage 66. .Instead of being discharged, it imparts a pressure impulse to the diaphragm |31 which is thereby exed to force a metered charge of fuel from the chamber .|29 through the check valve |55 into the conduit |56. When the. controlling edge 81b uncovers the port 6|, the fluid displaced by the remaining portion of the delivery stroke is expelled through the passages 65, 66 and 6| into the chamber insthe bore 6|l. At the same time, the fluid which on the effective portion of the delivery stroke passed through the discharge passage 68 is forced back through the passage 66 by the relatively low pressure of the 'fluid in the chamber |29, and/or the tendency of the diaphragm to assume its normally ilat shape. As the diaphragm |31 returns to its normal position, fuel passes from the chamber |45 through the passage |46 to refill the chamber |29.v It will be evident that the fuel oil, which'is likely to contain dirt, grit and other foreign matter, cannot intermingle with the lubricating oil, and never contacts with ythe bearing surfaces of the plungers |1 to 22.
I claim as my invention:
1. A pump comprising, in combination, a body having an inlet bore and a plurality of parallel annularly arranged cylinders with discharge passages opening respectively from the closed ends of said cylinders and inlet passages opening from said bore respectively to the sides of said cylinders, said inlet passages opening tangentially from said bore so that the'discharge of fluid thereto will impart a swirling motion to the fluid in said bore tending to effect uniform distribution of fluid to said inlet passages, a throttle member slidably disposed in said .bore and being axially adjustable to vary the effective inlet areas of said inlet passages, a plurality of pump plungers mounted for reciprocation and rotary adjustment respectively in said cylinders, means for reciprocating said usl plungers in timed sequence, each of said plungers being formed with a peripheral groove vented to the .closed end of the associated cylinder and movable at the end of the effective portion of the pressure stroke of the plunger into communication with the associated inlet passage to effect pressure relief, and with a peripheral inclined land area in advance of said groove and movably reversibly across said inlet passage to open and close the latter respectively at the end of the suction stroke and the -beginning'of the pressure stroke, and means for simultaneously rotatably adjusting said plungers to vary the effective position of said areas relative to said inlet passages.
2. A pump comprising, in combination, a body having an axial inlet bore and a/plurality of parallel cylinders annularly arranged .in uniformly spaced relation about said bore with discharge ing to effect uniform distribution of fluid to said inlet passages, a throttle member slidabl'y dis.-
posed in said bore and formed with a peripheral groove having a conical portion axially adjustable into different positions across said inlet passages to vary the effective inlet area of said inlet passages, a plurality of pump plungers mounted for 'l5 reciprocation and rotary adjustmentrespectively in said cylinders. means for reciprocating said lplungers in timed sequence, each of said plungers being formed with a peripheral groove vented to the closed'end of the associatedcylinder and movable at the end of the effective portion of thel reversibly across said inlet passage to open and close .the latter respectively at the end of the suction stroke and the beginning oi lthe pressure stroke, and means for simultaneously rotatably adjusting said plungers to vary the eiiective position of said areas relative to said inlet passages.
3. A pump comprising, in combination, a body having an inlet bore and a plurality of parallel annularly arranged cylinders with discharge passages vopening respectively' from the the closed ends of said cylinders and inlet passages opening from said bore respectively to the sides of said cylinders, said inlet passages opening tangentially from saidv bore so that vthe discharge of fluid thereto will impart a swirling motionto the fluid in said bore tending to eilect uniform distribution oi'iiuid to said inlet passages, a throttle member slidably disposed in said bore and being axially adjustable to vary the eiiective inlet areas of said inlet passages, a plurality or pump plungers mounted for reciprocation and rotary adjustment respectively in said cylinders, means for reciprocating said plungers in timed sequence, each of -said plungers being formed with a peripheral groove vented to the closed end of the associated cylinder and movable at the end of the effective portion of the pressure stroke of the plunger into communication with the associated inlet passage to eiect pressure relief, and with a peripheral inciined land area in advanceoi' said groove and movable reversibly across said inlet passage to open and close Athe latter respectively at 'the end of the suction stroke and the beginning oi the pressurestroke, a central gear mounted in said body, a plurality of pinions respectively on said plungers and meshing with said gear in allpositions of reciprocation of said plungers, and means for rotating said' central gear to eect simultaneous rotary adjustment of said plungers so as to adjust the eiective position 'f said areas relative to said inlet passages.
' JAMES F. KOFFER.