Valve controlled reversible pump

The pump drive shaft may rotate in either direction. The pump discharges liquid from the same port, regardless of the direction of rotation. A port on the pump mounting pad, which receives the discharge from the pump, may be in any of various locations. The pump has plural discharge ports at different locations on its base plate, one of which is aligned with the receiving port on the mounting pad. Any discharge port not used in any particular embodiment is blocked. The pump includes a base plate, a pump plate and a cover plate, aligned in a stack. In one modification, all fluid passages and a valve means which controls the direction of the flow are located in the base plate. In other modifications, a valve plate is provided, and the valve means is located in the valve plate. The fluid passages may be completely in the valve plate or partly in some of the other plates. All valves are simple structures trapped in chambers between or within the plates. Some modifications have noise reduction means, including a tortuous inlet passage and pump gear teeth wide enough to block that passage periodically. One embodiment has a valve which opens easily to a restricted flow position to facilitate purging of air from the pump.

CROSS-REFERENCE 
This invention is an improvement on the reversible pump disclosed in my 
U.S. Pat. No. 3,960,469 issued June 1, 1976. 
BRIEF SUMMARY 
The pumps described herein are intended as replacements for original 
equipment, for example, on oil burners. The pump drive shaft on some oil 
burners rotates clockwise, and on others it rotates counterclockwise. This 
replacement pump discharges liquid from one discharge port, regardless of 
the direction of rotation of the drive shaft. Furthermore, the port on the 
pump housing for receiving liquid from the pump may be located in 
different positions with respect to the drive shaft on different pump 
housings. This replacement pump is adaptable to deliver liquid to any of 
various discharge ports. In any particular pump, the discharge port 
selected is aligned with the receiving port of the pump housing when the 
pump is in place on its mounting pad. All other discharge ports are 
blocked. 
The pump structures shown are simple and easy to mount on an oil burner or 
other device with which it is intended to be used. The pumps are quiet in 
operation, as is particularly required for use on domestic oil burners. 
Pumps of the present invention comprise a base plate which engages the 
mounting pad of the pump housing, a pump plate which encloses the pump 
elements and a cover plate. Some modifications also include a valve plate, 
which encloses a valve mechanism that determines the direction of 
discharge from the pump. In the modification with no valve plate, the 
valve mechanism is within the base plate. 
In all modifications, the valves are simple discs or balls trapped in 
chambers and moved by fluid pressure to perform their control functions.

DETAILED DESCRIPTION 
FIGS. 1 and 2 show a complete pump assembly including a housing 1 having a 
mounting pad 1a on which a pump generally indicated at 3 is supported. The 
housing 1 encloses a drive shaft 4 adapted for connection to a motordriven 
shaft on the oil burner. A cover 5 encloses the end of the housing 1 
opposite the drive shaft 4. The housing 1 and the cover 5 enclose a 
chamber 6 connected to an inlet 7 and normally fill with oil or other 
liquid to be pumped A pressure regulating valve 10, of conventional 
construction, is located in another chamber in the housing 1 and delivers 
the fluid being pumped through a discharge conduit 11 at substantially 
constant pressure. 
The pump assembly 3 includes a base plate 12, a pump plate 13, a crescent 
plate 14, a valve plate 15 and a cover plate 16. The plates 12, 13, 14, 15 
and 16 are stacked and are attached to the mounting pad 1a by means of 
screws 17. A screen 20 of conventional construction encloses the pump 
assembly. The base plate 12, as shown in FIG. 3, includes five apertures 
to receive the screws 17, an aperture to receive the shaft 4 and two 
discharge passages 21a, 21b, one of which communicates with the discharge 
line 11 in FIGS. 1 and 2, through a delivery port in the casing 1 (not 
shown). 
The pump plate 13 is an annulus and rotatably encloses a gear pump incluing 
an internally toothed ring gear 22 cooperating with a pinion 23 fixed on 
the shaft 4. Either the gear 22 or pinion 23 may be termed a rotor. The 
crescent plate 14 has fixed on its rear side a crescent 18 which fills the 
space between the pinion 23 and the ring gear 22. The plate 14 also 
includes four axially extending passages 14a, 14b, 14c and 14d. The valve 
plate 15 also has four axially extending passages 15a, 15b, 15c and 15d 
aligned with and communicating with the correspondingly lettered passages 
in the crescent plate 14. Valve plate 15 also includes two additional 
axial passages 15e and 15f. 
Cover plate 16 has two inlet ports 16a and 16b which communicate with the 
correspondingly lettered passages in the valve plate 15. Passages 15a, 
15b, 15e and 15f in the valve plate 15 are enlarged at their ends adjacent 
the plate 16 to form valve chambers. Four valve discs 24, 25, 26 and 27 
are trapped in these valve chambers, which are closed at one end by the 
cover plate 16. 
OPERATION OF FIGS. 1-7 
The pump 3 runs submerged, with the housing 1 filled with oil or other 
liquid being pumped. The pump rotors 22 and 23 draw in liquid at the 
locality where the rotor teeth separate and discharge liquid from the 
locality where the teeth are forced together. When shaft 4 is rotating in 
a clockwise direction, as viewed in FIG. 3, liquid is drawn into the pump 
through the inlet passage 16a in the cover plate and passes through 
passages 15a, bypassing valve 24 through a groove 31 in the side of its 
valve chamber, and thence through the passage 14a to the locality of the 
pump where the rotor teeth are separating. The liquid is carried around by 
the rotor teeth to the locality where the teeth are engaging, whence the 
fluid is discharged through the passages 14b and 15b and against the valve 
disc 25 (the right-hand side as viewed in FIG. 8). The valve 25 is thereby 
forced to its dotted line position against the cover plate 16, closing the 
inlet port 16b. The passage 15b communicates through a groove 32 (FIGS. 4, 
5 and 8) in the back of the valve plate 15 with the passage 15f. The 
liquid under pressure acts against the bottom of the valve disc 27, as 
viewed in FIG. 7, and forces it open, so that the liquid flows into the 
conduit 33 and thence into a connected manifold 34 (FIG. 4) which branches 
into discharge conduits 34a and 34b. Conduit 34a is in communication 
through passages 15c, 14c and 13a with the discharge passage 21a in the 
base plate 12. Conduit 34b communicates with passages 15d and 14d, but 
flow therethrough is blocked by the pump plate 13. 
Alternatively, the pump plate may be rotated 180.degree. about a vertical 
axis so as to align the passage 13a with passages 14d and 21b. The base 
plate 12 is provided with the two discharge passages 21a, 21b, in order 
that it may deliver liquid selectively to either of two receiving port 
locations in the housing 1. Any particular housing 1 has only one 
receiving port which may be aligned with either passage 21a or 21b. Thus, 
the pump may be assembled to conform to the locations of the receiving 
port in the housing. Since the pump is intended to be suitable for 
replacement use, and the housing may be a re-used part, it is desirable 
that the pump be adaptable to either location of the receiving port. 
When the shaft 4 is rotating counterclockwise, as viewed in FIG. 3, liquid 
enters through the passage 16b, (FIGS. 3 and 8), and the valve 25 is 
forced to the right to the full line position shown in FIG. 8, so that the 
valve is bypassed through a groove 35 in the plate 15. The liquid flows 
through the passage 14b into the locality between the pump rotors where 
the gear teeth are separating and then moves around with the gears and is 
discharged through the passage 14a where the gear teeth are engaging. The 
liquid under pressure discharged at this point flows into passage 15a, 
moving the valve 24 to close the inlet port 16a. The liquid then flows 
through the passage 36 and thence under the valve 26, lifting that valve 
as viewed in FIG. 7, and thence through passage 33 and the discharge 
manifold 34 to the branch discharge passages 34a and 34b, as in the case 
when the shaft rotation was in the opposite direction. 
FIGS. 9-17 
These figures illustrate a modified form of replacement pump embodying the 
invention, which may be inserted in the same housing as that employed with 
the pump of FIGS. 1-8. The parts of the housing are illustrated in FIG. 9 
and have been given the same reference numerals. 
The pump assembly is illustrated at 40 in FIG. 9, and is shown in detail in 
FIGS. 10-17. 
The pump assembly 40 includes a base plate 41, a pump plate 42, a valve 
plate 43 and a cover plate 44. The base plate 41 includes five holes for 
the insertion of mounting screws, two discharge ports 41a, 41b disposed at 
either side of the lower mounting hole, as shown in FIG. 12, an aperture 
to receive the shaft 4, and four passages 41c, 41d, 41e and 41f. The pump 
plate 42 encircles a gear pump comprising a ring gear 45 and a pinion gear 
46. The pump plate 42 is annular and includes axially extending passages 
42d and 42e respectively aligned with the correspondingly lettered 
passages in the base plate 41. 
The valve plate 43 includes axially extending passages 43c, 43d, 43e, 43f 
and 43g. The gear side of the valve plate 43 carries a crescent 47 which 
extends between the ring gear 45 and the pinion 46. A groove 50 is cut in 
the outer face of the valve plate 43, and connects the passages 43e and 
43g. On the reverse side of the plate 43, an arcuate passage 51 (FIG. 14) 
connects the passages 43d, 43e and 43f. On the reverse side of the base 
plate 41 (FIG. 12), a groove 52 connects passages 41c and 41e. The two 
discharge ports 41a, 41b are connected through grooves 53 and 54 to the 
passages 41d and 41f, respectively. 
The cover plate 44 has axially extending inlet ports 44a and 44b. 
The passages 43c, 43e and 43g are stepped, each having a wide diameter 
section separated from a narrow diameter section by a shoulder part way 
through the passage. The shoulder in passage 43e serves as a seat for a 
disc valve 55 (FIGS. 15 and 17). A shoulder in the passage 43g (FIG. 17) 
faces in the opposite direction and serves as a seat for a disc valve 56. 
A similar shoulder in the passage 43c (FIG. 16) serves as a seat for a 
disc valve 57, facing in the same directon as the seat for valve 56 (FIG. 
17). 
OPERATION OF FIGS. 9-17 
When the pump is rotating in a clockwise direction as viewed in FIG. 10, 
liquid is drawn into the pump from the chamber 6 through the inlet port 
44a and passage 43c (FIG. 16), bypassing the valve 57 by means of a groove 
60 which extends along one side of the passage 43c. The liquid enters the 
space between the pinion 46 and gear 45 at a locality where the gear teeth 
are separating, and is carried around with those gears until they reach a 
locality where the teeth are moving together so that the space is 
decreasing. The liquid is there discharged through the passage 43g (FIG. 
17), where it lifts the valve 56 from the position shown in FIG. 17 to the 
dotted line position where it blocks the inlet port 44b. The liquid then 
flows through the groove 50 into the passage 43e. The liquid is there 
effective to move the valve 55 to the dotted line position shown in FIG. 
17, blocking the passage 42e. The liquid flows from the passage 43e 
through the arcuate passage 51 (FIGS. 13 and 14) to either one of the 
passages 43d and 43f. When the pump plate 42 is assembled in the 
orientation shown in FIG. 10, the liquid flows through passage 43d and 
thence through passages 42d and 41d, groove 53 and discharge port 41a to 
the receiving port of the housing 1. 
The housing 1 typically has only one receiving port, which may be aligned 
with either discharge port 41a or 41b. If the receiving port is aligned 
with discharge port 41b, then pump plate 42 is rotated during assembly on 
its vertical axis to align passage 42d with passages 43f and 41f. The flow 
is then through passages 43f, 42d and 41f to groove 54 and discharge port 
41b. 
If the pump gears 45 and 46 are rotating in the counterclockwise directon, 
then liquid is drawn in through the inlet port 44b and enters passage 43g, 
bypassing the valve 56 through the open slot 59 (FIG. 17) and entering the 
locality between the gears where the space between the teeth is expanding. 
The liquid is carried around with the gears until it gets to the other 
side where the teeth are being forced together. The liquid under the 
pressure developed by the pump acts through passage 43c (FIG. 16) against 
valve 57, moving the valve to the dotted line position and closing inlet 
port 44a. The liquid is discharged from the pump rotors through the 
passage 41c (FIGS. 10-12) groove 52 and passage 41e in base plate 41, and 
thence through passage 42e to the passage 43e , where it is effective to 
move the valve 55 to the closed position shown in solid lines in FIG. 17, 
so that the path of flow into the groove 50 is blocked. The liquid then 
flows through the arcuate passage 51 to one of the discharge passages 43d 
and 43f, and thence along one of the paths previously traced to the 
delivery port. 
FIGS. 18-22 
The pump shown in these figures is, like the previous modifications, 
intended for insertion in the same pump casing 1 shown in FIG. 1. In FIG. 
18, the parts which correspond to their counterparts in FIG. 1 have been 
given the same reference numerals. The pump assembly in FIG. 18 is shown 
at 61 and comprises a base plate 62, a pump plate 63 and a cover plate 64. 
In the pump 61, all of the fluid passages and a single valve 65 which 
controls the direction of the liquid flow are located in the base plate 
62. The pump plate 63 encircles a ring gear 66 and a pinion gear 67 of a 
crescent pump. The cover plate 64 closes the outer side of the pump plate 
63, and carries a crescent 64a which fills the space between the gears 66 
and 67. The inlet to the pump 61 is through a port 62a formed as a groove 
in one side of the base plate 62. The passage 62a connects with a 
connected series of tortuous passages and grooves in the base plate 62, 
including an axial passage 70, a groove 71 in the bottom face of the plate 
62, an axial passage 83, a groove 62d, 62e cut in the outer face of the 
base plate 62 and separated by a shoulder midway of its length, into a 
wider passage section 62d and a narrow passage section 62e below the 
shoulder. Most of the narrow section 62e is continuously covered by the 
crescent 64a when the pump is operating. The ends of the narrow section 
62e, which serve as an inlet port for the pump rotor means, are 
alternately covered and uncovered by the gear teeth. In this pump, the 
liquid enters the spaces between the gear teeth from the passage section 
62e at the point of widest separation of the gears, rather than at the 
locality where the gear teeth are separating, as in previous 
modifications. The rotation of the pump rotors 66, 67 forces fluid out 
through one of two ports 62b or 62c, depending upon the direction of 
rotaton of the pump. 
The ports 62b and 62c communicate with axial passages 72 and 73, 
respectively. Passage 72 communicates with a groove 74 on the back side of 
the plate 62 which in turn communicates with the axial passage 73. The 
axial passage 73 is best seen in FIG. 22, and includes a shoulder 73a 
midway of its length, separating the narrow section 73b from a wide 
section 73c. An annular insert 75 is press fitted in the wide section 73c 
and has a slot 75a cut in one side thereof and communicating with the 
groove 74. The insert 75 has a central axial aperture 75b. The valve 65 is 
trapped between the shoulder 73a and the insert 75. When the valve 65 is 
against the shoulder 73a, as shown in full lines in FIG. 22, the narrow 
section 73b of the passage 73 is closed and the flow from the pump is from 
groove 74 through slot 75a, aperture 75b and wide passage section 73a into 
an outlet passage 76 which is forked and delivers liquid to either of 
grooves 76a and 76b. Groove 76a leads through axial passage 77a, and 
groove 78a to axial passage 79a. Similarly, groove 76b leads through axial 
passage 77b and groove 78b to axial passage 79b. Only one of the passages 
79a, 79b communicates with the receiving port formed in any particular 
housing 1. The other passage is blocked at the mounting pad. The pump 
structure shown is adapted for insertion in pump housings 1 which may have 
their receiving ports in either of two locations. 
OPERATION OF FIGS. 18-22 
When the pump rotates clockwise as viewed in FIG. 19, liquid flows through 
inlet port 62a to groove 62d, 62e and is driven by the pump rotors through 
the port 62b, axial passage 72, groove 74 and passage 73, where the liquid 
pressure is effective to seat the valve 65 against the shoulder 73a so 
that the liquid flows into the outlet passage 76. 
When the pump rotates in the counterclockwise direction, the liquid passes 
through the same inlet conduit as before to the channel 62e and then is 
moved by the pump to the port 62c. It then flows into the passage section 
73b, forcing the valve 65 against the insert 75 and closing the opening 
75b in that insert so that the liquid enters the outlet passage 76, as 
before. 
The noise of operation of the pump 61 is reduced in the structure shown by 
the tortuous inlet passages 62a, 70, 71, 83, 62d, and by the tortuous 
outlet passages 76a, 77a, 78a, 79a and 76b, 77b, 78b, 79b. These tortuous 
passages reduce the transmission of noise through the liquid. Making the 
teeth of the pump gears 66 and 67 wider than the channel 62e also assists 
in minimizing the noise. 
FIGS. 23-27 
The pump shown in these figures is, like the previous modifications, 
intended for insertion in the pump casing shown in FIG. 1. In FIG. 23, the 
parts which correspond to their counterparts in FIG. 1 have been given the 
same reference numerals. 
The pump assembly in FIG. 23 is shown at 85 and comprises a base plate 86, 
a pump plate 87, and a cover plate 88. In the pump 85, all of the fluid 
passages and two valves 96 and 97 which control the directon of the fluid 
flow are located in the base plate 86. The pump plate 87 encircles a ring 
gear 89 and a pinion gear 90 of a crescent pump. The cover plate 88 closes 
the outer side of the pump plate 87, and carries a crescent 88a which 
fills the space between the gears 89 and 90. The inlet port 86a to the 
pump 85 is a groove in one side of the base plate 86. The inlet port 86a 
connects with a series of tortuous passages and grooves in the base plate 
86, including an axial passage 91, a groove 92 (FIG. 26) in the bottom 
face of the plate 86, an axial passage 93, and a groove 86d, 86e (FIGS. 24 
and 25) in the outer face of the base plate. A shoulder separates the wide 
groove section 86d from the narrow groove section 86e. Most of the narrow 
groove section 86e is covered by the crescent 88a. The ends of the narrow 
groove section 86e are alternately covered and uncovered by the teeth of 
the rotating gears 89 and 90. The fluid enters the gear teeth from groove 
section 86e at the point of widest separation of the gears, rather than at 
the locality where the gears are separating, as in more usual pumps. The 
rotation of the pump rotors 89 and 90 forces fluid out through one of two 
axial passages 86b or 86c, depending upon the direction of rotaton of the 
pump. 
Passage 86b communicates with a groove 94a on the inner face of plate 86 
which in turn communicates with an axial passage 95. Passage 95 is a 
stepped passage having a shoulder 95a (FIG. 27) separating the narrow 
section 95b from a wide section 95c. The wide section 95c communicates 
with a groove 98. A ball valve 97 is trapped between the shoulder 95a and 
the pump plate 87. A spring 99 is retained between pump plate 87 and ball 
valve 97. The unstressed length of spring 99 is somewhat shorter than the 
spacing between plate 87 and ball valve 97 when the valve is seated 
against should 95a. Spring 99 biases the ball valve 97 to a position near 
shoulder 95a so that any liquid movement from groove 98 through passage 
95c toward groove 94a causes ball valve 97 to close against shoulder 95a 
thereby shutting off flow to groove 94a. When the flow is reversed by 
reversing the rotation of gears 89 and 90, air moving from passages 94a 
can open valve 97 without compressing the spring. Since the movement is 
horizontal, only small friction forces have to be overcome. Once air is 
purged from the pump, the pressure of the liquid being pumped will 
compress spring 99, and move ball 97 far enough to cause the liquid to 
flow to groove 98. Groove 98 communicates with two discharge ports 100a 
and 100b one of which communicates with the receiving port formed in the 
casing 1. Note that groove 98 extends through one of the apertures for 
receiving a mounting screw 17. The aperture in question is shown at 102 in 
the drawings. The aperture is sufficiently larger than the screw 17 so 
that the screw does not appreciably restrict the flow through groove 98. 
Passage 86c communicates with a valve-controlled flow path similar to that 
just described in connection with passage 86b, but not shown in as great 
detail in the drawing. The flow path from passage 86c may be traced 
through a groove 94b, a passage 101 corresponding in structure and 
function to passage 95, a valve in that passage and groove 98 to the 
discharge ports 100a and 100b. Valve 96 corresponds in structure and 
function to valve 97, and is similarly biased by a spring. 
OPERATION OF FIGS. 23-27 
When the pump rotates clockwise as viewed in FIG. 24, liquid is pumped 
through inlet 86a to the groove 86d, 86e and is driven by the pump rotors 
through the axial passage 86b, groove 94a and passage 95, where the liquid 
pressure is effective to move valve ball 97 off shoulder 95a so that 
luquid passes into groove 98. Flow is then from groove 98 into passages 
100a and 100b (one of which is aligned with the receiving port in casing 
1) and into passage 101 where the liquid pressure is effective to move 
ball valve 96 against its seat. 
When the pump rotates in the counterclockwise direction, the fluid passes 
through the same inlet route as before. Liquid is then pumped by the gears 
through passage 86c and groove 94b to passage 101 where liquid pressure is 
effective to move ball valve 96 off its seat and thereby to allow flow to 
groove 98. Flow is then from groove 98 through passage 100a or 100b to the 
receiving port in casing 1. Liquid also flows from groove 98 into passage 
95c where the liquid pressure is effective to move ball valve 97 against 
the shoulder 95a blocking flow to groove 94a. 
The noise of operation of the pump 85 is reduced in the structure shown by 
the tortuous inlet passages 86a, 91, 92, 93, 86d, 86e. These tortuous 
passages reduce the transmission of noise through the fluid. The teeth of 
the pump gears 89 and 90 are wider than the groove 86e which also assists 
in minimizing the noise. 
The pumps illustrated are shown with two discharge ports, so that any such 
pump may be used with a pump housing having an oil receiving port at 
either of two locations. Commonly, a mounting pad in a pump housing has 
its receiving port located with respect to the drive shaft in either a 
right-hand or a symmetrical left-hand location. The discharge outlets in 
the pumps illustrated have been located with such conventional mounting 
pads in view. However, if more than two possible locations of the delivery 
passage may be encountered in a particular situation, additional discharge 
ports may be provided in the pumps. The ones not used are blocked at the 
mounting pad. 
While the pumps illustrated are gear pumps of the crescent type, the 
invention is readily adaptable to other suitable conventional pumps, such 
as gear pumps using two externally toothed gears, sliding vane pumps, etc. 
While some valves are illustrated as disc valves and others as ball valves, 
either type of valve could be used for any of the illustrated valves. 
Furthermore, other types of valve, e.g., reed valves, might be used.