U.S. patent application number 13/841029 was filed with the patent office on 2014-06-12 for compact integrated-drive pumps.
This patent application is currently assigned to Micropump, Inc, a Unit of IDEX Corporation. The applicant listed for this patent is MICROPUMP, INC, A UNIT OF IDEX CORPORATION. Invention is credited to David J. Grimes.
Application Number | 20140161651 13/841029 |
Document ID | / |
Family ID | 50881141 |
Filed Date | 2014-06-12 |
United States Patent
Application |
20140161651 |
Kind Code |
A1 |
Grimes; David J. |
June 12, 2014 |
COMPACT INTEGRATED-DRIVE PUMPS
Abstract
Pump assemblies are disclosed that have a magnetically driven
pump-head subassembly and a pump-driver subassembly coupled
thereto, wherein the pump-driver subassembly includes a pump-driver
enclosure. The pump-head subassembly comprises a rotatable magnet
contained in a magnet cup extending into the pump-driver enclosure.
The pump-driver subassembly has a printed circuit board (PCB) in
the pump-driver enclosure and a stator mounted to the PCB. The
stator coaxially surrounds the magnet cup. The magnet cup has a
distal-end wall. The printed circuit board includes a
stator-driving circuit and at least one signal-processing circuit.
The PCB defines a void relative to the distal-end wall that exposes
at least half the distal-end wall. The pump-driver enclosure has an
aspect ratio of no greater than one (unity).
Inventors: |
Grimes; David J.;
(Beaverton, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MICROPUMP, INC, A UNIT OF IDEX CORPORATION |
Vancouver |
WA |
US |
|
|
Assignee: |
Micropump, Inc, a Unit of IDEX
Corporation
Vancouver
WA
|
Family ID: |
50881141 |
Appl. No.: |
13/841029 |
Filed: |
March 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61735872 |
Dec 11, 2012 |
|
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|
Current U.S.
Class: |
417/420 |
Current CPC
Class: |
F04B 17/042 20130101;
F04C 15/008 20130101; F04B 17/03 20130101; F04C 2/18 20130101; H02K
11/33 20160101; H02K 11/30 20160101; F04C 11/008 20130101; H02K
29/08 20130101; F04C 2/102 20130101; F04B 53/22 20130101; F04C
15/0069 20130101; F04B 53/16 20130101; F04C 2/086 20130101; H02K
2211/03 20130101; H02K 5/04 20130101; F04C 2240/808 20130101 |
Class at
Publication: |
417/420 |
International
Class: |
F04B 17/03 20060101
F04B017/03 |
Claims
1. A pump assembly, comprising: a magnetically driven pump-head
subassembly and a pump-driver subassembly coupled to the pump-head
subassembly, the pump-driver subassembly including a pump-driver
enclosure; the pump-head subassembly comprising a rotatable magnet
contained in a magnet cup extending into the pump-driver enclosure;
the pump-driver subassembly comprising a printed circuit board
contained in the pump-driver enclosure and a stator mounted to the
printed circuit board, the stator coaxially surrounding the magnet
cup; the magnet cup comprising a distal-end wall; the printed
circuit board including a stator-driving circuit, and at least one
signal-processing circuit; and the printed circuit board defining a
void that is situated relative to the distal-end wall so as to
expose at least half the distal-end wall; and the pump-driver
enclosure having an aspect ratio of no greater than one
(unity).
2. The pump assembly of claim 1, wherein the printed circuit board
further comprises at least one pump-parameter sensor mounted
thereto.
3. The pump assembly of claim 2, wherein the sensor is placed on,
aside, or at least partially in the distal-end wall.
4. The pump assembly of claim 1, wherein the printed circuit board
is annular in shape, and the void is a central hole of the annular
printed circuit board.
5. The pump assembly of claim 1, wherein: the magnet cup includes a
substantially cylindrical side wall; and the printed circuit board
is a flexible printed circuit curved into a cylinder and situated
to surround the side wall in a coaxial manner.
6. The pump assembly of claim 1, wherein the movable pumping member
comprises a pump gear.
7. The pump assembly of claim 1, wherein the movable pumping member
comprises a piston.
8. A pump assembly, comprising: a pump-head portion including a
pump housing defining a pump cavity; a pump-driver enclosure
coupled to the pump-head portion having an axial length and a
transverse dimension; a movable pumping member situated inside the
pump cavity; a driven magnet connected to the pumping member so
that induced motion of the driven magnet causes corresponding
induced motion of the pumping member; a magnet cup being a
respective portion of the pump cavity and containing the driven
magnet so that the induced motion of the driven magnet occurs in
the magnet cup as the driven magnet and interior of the magnet cup
are being wetted by fluid being pumped by induced motion of the
pumping member, the magnet cup including a distal-end wall; a
magnet-driver situated outside the magnet cup but inside the
pump-driver enclosure, the magnet driver being magnetically coupled
to the driven magnet such that a changing magnetic field produced
by the magnet-driver induces motion of the driven magnet and hence
of the pumping member in the magnet cup; a circuit board and at
least one sensor being located in the pump-driver enclosure;
wherein the sensor is located on, aside, or at least partially in
the distal-end wall; and the circuit board is electrically
connected to the magnet-driver and to the at least one sensor; and
wherein the circuit board comprises a high-current circuit and a
low-current circuit, the high-current circuit being connected to
and providing controlled electrical power to the magnet-driver, the
low-current circuit being connected to and providing controlled
electrical power to the at least one sensor; and the circuit board
extends orthogonally to the axial length around the magnet cup
while defining a void allowing access through the circuit board to
the distal-end wall of the magnet cup.
9. The pump assembly of claim 8, wherein the sensor is sealingly
mounted with respect to a wall of the magnet cup such that the
sensor is not wetted by the fluid.
10. The pump assembly of claim 8, wherein the pump-driver enclosure
is substantially cylindrical in shape, with an axial length and a
diameter.
11. The pump assembly of claim 10, wherein the circuit board is
substantially annular in shape.
12. The pump assembly of claim 10, wherein the ratio of the axial
length of the pump-driver enclosure to the diameter of the
pump-driver enclosure is approximately 0.25 to approximately 1.
13. The pump assembly of claim 12, wherein the ratio of the axial
length of the pump-driver enclosure to the diameter of the
pump-driver enclosure is between approximately 0.4 and 0.7.
14. The pump assembly of claim 10, wherein the ratio of the axial
length of the pump-driver enclosure to the diameter of the
pump-driver enclosure is approximately 0.5.
15. The pump assembly of claim 8, wherein the circuit board and the
distal-end wall of the magnet cup are substantially coplanar.
16. The pump assembly of claim 8, wherein the at least one sensor
is sealingly mounted to the distal-end wall of the magnet cup.
17. The pump assembly of claim 8, configured as a flow-through
pump.
18. The pump assembly of claim 17, wherein the pump assembly
comprises a first fitting mounted to the pump cavity and a second
fitting mounted to the distal-end wall of the magnet housing.
19. The pump assembly of claim 18, wherein the first fitting is an
outlet fitting, and the second fitting is an inlet fitting.
20. A pump assembly, comprising: a pump-head portion including a
pump housing defining a pump cavity; a pump-driver enclosure; a
movable pumping member situated inside the pump housing; a driven
magnet connected to the pumping member so that induced motion of
the driven magnet causes corresponding induced motion of the
pumping member; a magnet cup being a respective portion of the pump
cavity and containing the driven magnet so that the induced motion
of the driven magnet occurs in the magnet cup as the driven magnet
and interior of the magnet cup are being wetted by fluid being
pumped by induced motion of the pumping member, the magnet cup
including a distal-end wall; a magnet-driver situated outside the
magnet cup but inside the pump-driver enclosure, the magnet-driver
being magnetically coupled to the driven magnet such that a
changing magnetic field produced by the magnet-driver induces
motion of the driven magnet and hence of the pumping member in the
magnet cup; a fitting mounted to the distal-end wall of the magnet
cup; and a circuit board and at least one sensor being located in
the pump-driver enclosure; wherein the sensor is located on, aside,
or at least partially in the distal-end wall; the circuit board is
electrically connected to the magnet-driver and to the at least one
sensor; the circuit board is substantially annular in shape
relative to the magnet cup; and the circuit board defines a central
void allowing access to the distal-end wall of the magnet cup.
21. The pump assembly of claim 20, wherein the circuit board allows
access to substantially the entire surface area of the distal-end
wall of the magnet cup.
22. The pump assembly of claim 20, wherein the circuit board allows
access to between approximately 50% and approximately 100% of the
surface area of the distal-end wall of the magnet cup.
23. The pump assembly of claim 22, wherein the circuit board allows
access to at least approximately 75% of the surface area of the
distal-end wall of the magnet housing.
24. The pump assembly of claim 20, configured as a flow-through
pump.
25. The pump assembly of claim 24, wherein the pump assembly
comprises a first fitting mounted to the pump-head portion and a
second fitting mounted to the distal-end wall of the magnet
cup.
26. The pump assembly of claim 20, wherein the aspect ratio of the
pump-driver enclosure is from about 0.5 to about 1.
27. A pump assembly, comprising: a pump-head portion comprising a
pump housing defining a pump cavity; a pump-driver enclosure
coupled to the pump-head portion and having an axial length and a
transverse dimension; a movable pumping member situated inside the
pump cavity; a driven magnet connected to the pumping member so
that induced motion of the driven magnet causes corresponding
induced motion of the pumping member; a magnet cup being a
respective portion of the pump cavity and containing the driven
magnet so that the induced motion of the of the driven magnet
occurs in the magnet cup as the driven magnet and the interior of
the magnet cup are being wetted by fluid being pumped by induced
motion of the pumping member, the magnet cup having a distal-end
wall; a magnet-driver situated outside the magnet cup but inside
the pump-driver enclosure, the magnet-driver being magnetically
coupled to the driven magnet such that a changing magnetic field
produced by the magnet-driver induces motion of the driven magnet
and hence of the pumping member in the magnet cup; an annular
circuit board defining a central void; a first sensor mounted to
the distal-end wall and connected to the circuit board; a second
sensor mounted to the circuit board and being situated relative to
an outside wall of the magnet cup; and the distal-end wall of the
magnet cup being exposed by the central void of the circuit
board.
28. A pump assembly, comprising: a pump-head portion comprising a
pump housing defining a pump cavity; a pump-driver enclosure
coupled to the pump-head portion and having an axial length and a
transverse dimension; a movable pumping member situated in the pump
cavity; a driven magnet connected to the pumping member so that
induced motion of the driven magnet causes corresponding induced
motion of the pumping member; a magnet cup being a respective
portion of the pump cavity and containing the driven magnet so that
the induced motion of the of the driven magnet occurs in the magnet
cup as the driven magnet and the interior of the magnet cup are
being wetted by fluid being pumped by induced motion of the pumping
member, the magnet cup having a distal-end wall; a magnet-driver
situated outside the magnet cup but inside the pump-driver
enclosure, the magnet-driver being magnetically coupled to the
driven magnet such that a changing magnetic field produced by the
magnet-driver induces motion of the driven magnet and hence of the
pumping member in the magnet cup; and a flexible printed circuit
electrically connected to the magnet-driver and at least one
sensor, the flexible printed circuit and the at least one sensor
being located in the pump-driver enclosure; wherein the sensor is
located on, aside, or at least partially in the distal-end wall;
and the flexible printed circuit is urged into an arcuate shape and
mounted within the pump-driver enclosure such that the flexible
printed circuit at least partially surrounds the magnet cup while
leaving the distal-end wall exposed.
29. The pump assembly of claim 28, wherein the pumping member
comprises at least one pump gear.
30. The pump assembly of claim 28, wherein the pumping member
comprises a piston.
32. A pump-driver assembly for rotatably driving a magnet located
in a magnet cup of a pump housing and connected to a pump element
located in the pump housing, the assembly comprising: a printed
circuit sized and configured to surround a portion of the magnet
cup, the printed circuit defining a central void through which a
distal-end face of the magnet cup is exposed, the printed circuit
including a high-current circuit and a low-current circuit; a
stator mounted to the high-current circuit on the printed circuit
and configured to surround the magnet cup in a coaxial manner
whenever the pump-driver assembly is fitted to the pump housing;
and at least one pump-parameter sensor electrically connected to
the low-current circuit on the printed circuit, the sensor being
positioned relative to the magnet cup to produce pump-parameter
data whenever the pump-driver assembly is fitted to the pump
housing.
33. The pump-driver assembly of claim 32, wherein the printed
circuit comprises a rigid annular board that is situated coaxially
with the magnet cup whenever the pump-driver assembly is fitted to
the pump housing.
34. The pump-driver assembly of claim 32, wherein the printed
circuit is flexibly configured as a strip looped into a cylinder
that is coaxial with the magnet cup whenever the pump-driver
assembly is fitted to the pump housing.
35. The pump-driver assembly of claim 27, further comprising a
housing enclosing the pump-driver assembly.
36. The pump-driver assembly of claim 35, wherein the housing has
an aspect ratio of no greater than unity.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to, and the benefit of,
U.S. Provisional Patent Application No. 61/735,872, filed on Dec.
11, 2012, which is incorporated herein by reference in its
entirety.
FIELD
[0002] This disclosure relates to various types of pumps that are
magnetically driven. More specifically, it pertains to pumps in
which a rotary or rotary-reciprocating element, such as a pump
gear, is connected to a driven magnet housed in a magnet housing
("magnet cup") in which the magnet is wetted by the fluid being
pumped by the pump.
BACKGROUND
[0003] Integrated-drive pumps are particularly advantageous for
pumping systems that must operate under severe conditions, handle
hazardous fluids, or operate trouble-free for extremely long
periods of time. Such pumps often incorporate a magnetically
coupled pump-drive mechanism in which a pump element, such as a
pair of interdigitating gears or lobes, is connected to a driven
magnet housed in a magnet housing or "magnet cup." The driven
magnet is caused to rotate by a rotating magnetic field induced by
a stator or other mechanism situated outside the magnet cup. This
arrangement allows the driven magnet to be immersed in the fluid
being pumped while isolating the rest of the system and eliminating
the leak-prone hydraulic seals that would otherwise be required
around the pump-drive shaft. Operation of the stator typically
requires an electronic circuit for provision of power and control
logic.
[0004] In addition to the electronic circuits required for
operation of the pump, integrated-drive pumps are often
incorporated into hydraulic systems that require sensors or
indicators of any of various parameters such as pressure,
temperature, conductivity, etc., of the fluid flowing in the
system. A sensor usually includes a transducer or the like that
converts the parameter being sensed (e.g., pressure or temperature)
into a corresponding signal (e.g., an electronic or optical
signal). The sensor usually also includes or is connected to an
electronic circuit that receives data directly from the transducer
and processes the data for use by other electronics for, e.g.,
providing a measure of the parameter or for use in control
circuits. It is possible that the sensor(s) not actually include or
function as a transducer. As used herein, the term "sensor"
encompasses both transducer-based sensors as well as sensors not
utilizing a transducer.
[0005] In hydraulic systems including a pump, the pump is typically
a discrete stand-alone component, by which is meant that the pump
is manufactured and sold separately to original equipment
manufacturers (OEMs) for incorporation into the OEM's own system.
The trend in many OEM hydraulic systems requiring a pump is toward
miniaturization, particularly with respect to the aspect ratio of a
pump assembly (i.e., the ratio of a pump assembly's axial length as
compared to its diameter) without sacrificing performance or
reliability. Thus, the electronic circuitry for operating both the
pump and the sensors ideally must be self-contained (i.e., located
on or within the housing or enclosure of a pump-driver portion),
and incorporated into a pump assembly that is as small and compact
as possible.
[0006] However, the circuitry needed to operate the stator in an
integrated-drive pump is often required to operate at a much higher
voltage and/or current than the circuitry for operating the sensors
due to the higher electrical power requirements of the stator
relative to the sensors. Additionally, each respective circuit type
requires numerous circuit elements which can vary in size. The
disparity in power requirements, the relatively large number and
size of the circuit elements, and the space constraints imposed by
the pump-driver portion often necessitate that the stator and
sensor elements be operated on two or more independent electrical
circuits. Moreover, these independent electrical circuits must
often be laid out on multiple printed circuit boards that fully
extend the full transverse dimension of the enclosure of the
pump-driver portion (or be located outside the enclosure) to
accommodate the required circuit elements. This, in turn, blocks
access to the magnet cup, complicates sensor location, precludes a
flow-through pump configuration, and requires a large pump-driver
portion that negatively impacts the size of the pump assembly.
SUMMARY
[0007] Disclosed embodiments of the present invention provide
compact integrated-drive pumps that address the deficiencies of
known integrated-drive pumps. Certain embodiments of the present
invention concern a pump assembly, comprising a magnetically driven
pump-head subassembly and a pump-driver subassembly coupled to the
pump-head subassembly. The pump-driver subassembly includes a
pump-driver enclosure. The pump-head subassembly comprises a
rotatable magnet contained in a magnet cup, which has a distal-end
wall and extends into the pump-driver enclosure. The pump-driver
subassembly also comprises a printed circuit board contained in the
pump-driver enclosure, and a stator mounted to the printed circuit
board. The stator coaxially surrounds the magnet cup. The printed
circuit board includes a stator-driving circuit, at least one
signal-processing circuit, and at least one pump-parameter sensor
mounted on the printed circuit board. The printed circuit board
also defines a void that is situated relative to the distal-end
wall so as to expose at least half of the distal-end wall while
placing the sensor relative to the magnet cup. In addition, the
pump-driver enclosure has an aspect ratio of no greater than one
(unity).
[0008] Another embodiment concerns a pump assembly, comprising a
pump-head portion including a pump cavity. The pump assembly
includes a pump-driver enclosure coupled to the pump-head portion
that has an axial length and a transverse dimension. A movable
pumping member is situated inside the pump cavity and connected to
a driven magnet so that induced motion of the driven magnet causes
corresponding induced motion of the pumping member. The pump
assembly also includes a magnet cup, being a respective portion of
the pump cavity, and containing the driven magnet. The induced
motion of the driven magnet occurs in the magnet cup as the driven
magnet and interior of the magnet cup are being wetted by fluid
being pumped by induced motion of the pumping member. The magnet
cup also includes a distal-end wall.
[0009] A magnet-driver is situated outside the magnet cup but
inside the pump-driver enclosure, and is magnetically coupled to
the driven magnet such that a changing magnetic field produced by
the magnet-driver induces motion of the driven magnet and hence of
the pumping member in the magnet cup. The pump assembly also
includes a circuit board and at least one sensor located in the
pump-driver enclosure. The sensor is located on, aside, or at least
partially in the distal-end wall, and the circuit board is
electrically connected to the magnet-driver and to the at least one
sensor.
[0010] The circuit board comprises a high-current circuit and a
low-current circuit, wherein the high-current circuit is connected
to and provides controlled electrical power to the magnet-driver,
and the low-current circuit is connected to and provides controlled
electrical power to the at least one sensor. The circuit board
extends orthogonally to the axial length around the magnet cup
while defining a void, which allows access through the circuit
board to the distal-end wall of the magnet cup.
[0011] The foregoing and other objects, features, and advantages of
the invention will become more apparent from the following detailed
description, which proceeds with reference to the accompanying
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a side-elevational section of an embodiment of an
integrated-drive pump assembly.
[0013] FIG. 2 is a top view of a printed circuit board used in the
embodiment of FIG. 1.
[0014] FIG. 3A is a schematic depiction of an integrated-drive pump
assembly having a pump-driver enclosure with an aspect ratio of
approximately 0.4.
[0015] FIG. 3B is a schematic depiction of an integrated-drive pump
assembly having a pump-driver enclosure with an aspect ratio of
approximately 0.7.
[0016] FIG. 4 is a side-elevation cross-sectional view of an
embodiment of an integrated-drive pump assembly having a
sensor.
[0017] FIG. 5 is a side-elevational section of an embodiment of an
integrated-drive pump assembly including a fitting mounted to the
distal-end wall of the magnet cup.
[0018] FIG. 6A is a perspective view of an exemplary configuration
of a flexible printed circuit.
[0019] FIG. 6B is an elevational section showing the printed
circuit of FIG. 6A and nearby portions of the magnet cup and
stator.
[0020] FIG. 7 is an elevational view of a portion of a pump-driver
assembly situated relative to the magnet cup.
[0021] FIG. 8 is a section through a portion of the head of an
embodiment of a piston pump as an alternative pump-head.
[0022] FIG. 9 is a schematic diagram of an exemplary hydraulic
circuit including an integrated-drive pump assembly.
DETAILED DESCRIPTION
[0023] This disclosure is set forth in the context of
representative embodiments that are not intended to be limiting in
any way.
[0024] As used herein, the singular forms "a," "an," and "the"
include the plural forms unless the context clearly dictates
otherwise. Additionally, the term "includes" means "comprises."
Further, the term "coupled" encompasses mechanical as well as other
practical ways of coupling or linking items together, and does not
exclude the presence of intermediate elements between the coupled
items.
[0025] The things and methods described herein should not be
construed as being limiting in any way. Instead, this disclosure is
directed toward all novel and non-obvious features and aspects of
the various disclosed embodiments, alone and in various
combinations and sub-combinations with one another. The disclosed
things and methods are not limited to any specific aspect or
feature or combinations thereof, nor do the disclosed things and
methods require that any one or more specific advantages be present
or problems be solved.
[0026] Although the operations of some of the disclosed methods are
described in a particular, sequential order for convenient
presentation, it should be understood that this manner of
description encompasses rearrangement, unless a particular ordering
is required by specific language set forth below. For example,
operations described sequentially may in some cases be rearranged
or performed concurrently. Moreover, for the sake of simplicity,
the attached figures may not show the various ways in which the
disclosed things and methods can be used in conjunction with other
things and method. Additionally, the description sometimes uses
terms like "produce" and "provide" to describe the disclosed
methods. These terms are high-level abstractions of the actual
operations that are performed. The actual operations that
correspond to these terms will vary depending on the particular
implementation and are readily discernible by one of ordinary skill
in the art.
[0027] In the following description, certain terms may be used such
as "up," "down,", "upper," "lower," "horizontal," "vertical,"
"left," "right," and the like. These terms are used, where
applicable, to provide some clarity of description when dealing
with relative relationships. But, these terms are not intended to
imply absolute relationships, positions, and/or orientations. For
example, with respect to an object, an "upper" surface can become a
"lower" surface simply by turning the object over. Nevertheless, it
is still the same object.
[0028] Referring to FIG. 1, there is shown a cross-sectional view
of an embodiment of an integrated-drive pump assembly 10 having a
pump-head portion 12 and a pump-driver portion 14. The pump-head
portion 12 includes an inlet 16, an outlet 18, a driving gear 20, a
driven gear 22, a shaft 24, a driven magnet 26, and a magnet cup
28. The magnet cup 28 extends into the pump-driver portion 14. The
magnet cup 28 has side walls 28a and a distal-end wall 30 that
surround and are coaxial with the driven magnet 26. The side walls
28a and the distal-end wall 30 separate the driven magnet 26 from
electrical parts of the assembly that are kept dry (i.e., not
wetted by the fluid being pumped). Meanwhile, the pump-head portion
12 comprises a pump housing 23 (usually a sealed housing) that
defines a pump cavity 25. The pump cavity 25 is generally bathed in
the fluid being pumped. In other words, the pump cavity 25 is
defined by the fluid-wetted interiors of the pump-head portion 12
and the magnet cup 28. Thus, the driven magnet 26 and gears 20, 22
are situated in the pump cavity 25. Coaxially surrounding the
magnet cup 28 is a stator 32 that is located outside the pump
cavity 25 and is magnetically coupled to the driven magnet 26
across the side walls 28a of the magnet cup. The stator 32 is
contained in a pump-driver enclosure 34. The pump-driver enclosure
34, being outside the pump cavity 25, is dry. In the embodiment
shown in FIG. 1, the pump-driver enclosure 34 and pump-head portion
12 are mounted end-to-end so that a large part of the pump-head
portion 12 extends from and is axially aligned with the pump-driver
portion 14.
[0029] In this embodiment, a printed circuit board (PCB) 36 is
located within the pump-driver enclosure 34 immediately above and
substantially adjacent the stator 32, as shown in FIG. 1. The PCB
36 of this embodiment has a substantially annular shape and defines
a central hole 46 coaxial with and having a diameter substantially
equal to or slightly larger than the outside diameter of the magnet
cup 28. Mounted to the PCB 36 are an electrical connector housing
38 for providing electrical power to the pump assembly and a
plurality of circuit elements 40, as shown in FIGS. 1-2. The PCB 36
is electrically connected to the stator 32 and to one or more
sensors 42 (FIG. 4) for sensing any of a variety of respective
parameters (e.g., pressure, temperature, etc.) of the fluid being
pumped.
[0030] The PCB 36 contains one or more electronic circuits that,
for example, provide controlled electrical power (i.e., electrical
power, logical control, signal conditioning, signal processing,
etc.) to the stator 32and to the one or more sensors 42. For
example, the PCB 36 of this embodiment comprises a high-current
electrical circuit for operating the stator 32 and at least one
low-current electrical circuit for operating the one or more
sensors 42. Desirably, the PCB 36 accommodates all the circuit
elements 40 of the circuits required to operate the stator 32 and
the one or more sensors 42 such that only a single printed circuit
board is required. In this manner, all the electrical components
are contained on or within the pump-driver enclosure 34 such that
all that is required from outside (i.e., from the OEM system) is
electrical power input. The integrated-drive pump assembly 10 can
also include an output for signals to or from the sensors 42 for
use by, for example, OEM systems remote from the pump assembly.
[0031] Alternatively, the necessary electronic circuits can be laid
out on two or more PCBs (not necessarily of similar size)
substantially adjacent one another (e.g., coaxially "stacked") or
otherwise in close proximity within the pump-driver enclosure 34.
Also, the PCB 36 need not be annular, but can comprise any shape
that would fit in the pump-driver enclosure 34 and allow access to
the distal-end wall 30 of the magnet cup 28 for location of sensors
or fittings. For example, the PCB 36 can comprise one or more
semi-annular printed circuit boards configured and arranged within
the pump-driver enclosure 34 such that the distal-end wall 30 of
the magnet cup 28 is accessible.
[0032] In the embodiment shown, the PCB 36 is configured such that
the distal-end wall 30 of the magnet cup 28 is at least partially
exposed through the central hole 46 of the PCB 36 when the PCB 36
is located above the stator 32 (i.e., at least a portion of the
distal-end wall 30 of the magnet cup 28 can be accessed through the
annular-shaped PCB 36), as best shown in FIGS. 1-2. In this manner,
the distal-end wall 30 of the magnet cup 28 can be accessed and
used for sensor location, as shown in FIG. 4, or for location of a
fitting 44 in a flow-through pump, as shown in FIG. 5. In this
application, a "flow-through pump" refers to a pump configured such
that the fluid being pumped enters an inlet 16 defined in or on the
pump cavity 25 and exits through an outlet 18 in the form of a
hydraulic fitting 44 or the like located on the distal-end wall 30
of the magnet cup 28 within the pump-driver enclosure 34. The
hydraulic fitting 44 mounted on the distal-end wall 30 of the
magnet cup 28 allows pumped fluid to follow a flow path extending
substantially in an axial direction with respect to the
integrated-drive pump assembly 10 (note axis A and flow lines 52),
as shown in FIG. 5. Alternatively, the hydraulic fitting 44 can be
mounted on the side wall 28a of the magnet cup 28 and the fluid can
follow a flow path that extends through the pump-driver portion 14
in a direction substantially normal to the axis A of the
integrated-drive pump assembly 10. In the embodiment shown,
desirably between approximately 50% to approximately 100% of the
surface area of the distal-end wall 30 is exposed through the
central hole 46 of the PCB 36. Most desirably, 75% or more of the
surface area of the distal-end wall 30 is exposed.
[0033] In an alternative embodiment, the PCB 36 is configured as a
flexible printed circuit sheet or "board", such as a polymeric
substrate in/on which circuit wiring is printed and circuit
elements are mounted. The flexible printed circuit can be
configured as a looped strip or ribbon 50, as shown in FIG. 6A. The
ribbon 50 is bent or urged into a substantially cylindrical loop
that is mountable inside the pump-driver enclosure 34. Thus, the
ribbon 50 at least partially surrounds the magnet cup 28 while
leaving the distal-end wall 30 exposed. A flexible printed circuit
can reduce the volume of the circuitry required to operate the
integrated-drive pump assembly 10, thereby reducing the size of the
pump-driver enclosure 34. A flexible printed circuit can also
provide enhanced possibilities for locating circuitry inside the
pump-driver enclosure 34 without compromising access to the
distal-end wall 30 of the magnet cup 28. For example, a flexible
printed circuit, such as the ribbon 50, could be used in
combination with the PCB 36 in the manner shown in FIG. 6B. As
shown in FIG. 6B, the ribbon 50 can be urged into a substantially
cylindrical loop with the PCB 36 (shown in phantom) located above
and substantially adjacent the ribbon 50 such that the distal-end
wall 30 of the magnet cup 28 is exposed. In other embodiments the
printed circuit has characteristics of both a looped ribbon and an
annulus.
[0034] Referring to FIG. 7, the PCB 36 can be configured such that
certain sensor(s), such as Hall sensors 60, are connected to one
face 64a of the PCB 36 while other sensor(s) 42 are connected (via
conductors 62) to the opposite face 64b of the PCB. This places the
Hall sensors 60 advantageously relative to the side wall 28a of the
magnet cup 28 for sensing rotation of the magnet 26, while placing
other sensors 42 advantageously relative to the distal-end wall 30
of the magnet cup. Similarly, other electronic components mounted
to the PCB 36 need not all be located on one face of the PCB (e.g.,
face 64b); rather both faces of the PCB can be used for mounting
components as conditions and/or size constraints dictate.
[0035] Further with respect to sensor location, one or more sensors
42 can be located on or relative to the distal-end wall 30 of the
magnet cup 28 and electrically connected to the PCB 36, as shown in
FIG. 4 (see also FIG. 7). In some embodiments, the one or more
sensors 42 can also be integrally formed with the distal-end wall
30 of the magnet cup 28 (i.e., a portion of the distal-end wall 30
can be configured to act as, or as a portion of, the sensor 42). As
a result, the sensor 42 is not actually wetted by the fluid.
However, if the parameter being sensed requires that the sensor(s)
42 be wetted by the fluid (e.g., conductivity sensors, pH sensors,
etc.), then the one or more sensors 42 can also be sealingly
mounted to the distal-end wall 30. (See, e.g., U.S. patent
application Ser. No. 13/151,188, incorporated herein by reference.)
In this application, "sealingly mounted" means that the sensor 42
or other element being mounted is held in a position so as to
maintain contact with at least a portion of the mounting surface at
one or more contact points at which a static seal prevents fluid
from passing through or across the surface. The static seal may
take the form of, for example, the surface itself, an o-ring, an
absorbent material, an adhesive material, or the like. In this
manner, one or more sensors 42 can extend through the distal-end
wall 30 of the magnet cup into the pump cavity 25, where they can
be wetted by the fluid, without leakage into the pump-driver
enclosure 34. Similarly, with respect to the location of a fitting
44, the fitting 44 can be sealingly mounted to the distal-end wall
30 of the magnet cup 28 such that the pump 10 can be configured as
a flow-through pump.
[0036] The pump-driver enclosure 34 desirably is cylindrical, with
an axial length dimension .alpha. and a transverse or radial
dimension .beta., as shown in FIGS. 3A-3B, such that an aspect
ratio of the pump-driver enclosure 34 can be defined by the
expression .alpha./2.beta.. Desirably, the aspect ratio of the
pump-driver enclosure 34 is as low as practicable to accommodate
the necessary driver components and stator while allowing the pump
10 to be incorporated into ever smaller OEM hydraulic systems. As a
practical matter, the radial dimension .beta. is limited by the
diameter of the driven magnet 26 and by the diameter of the stator
32, which must surround the driven magnet 26 to cause axial
rotation of the magnet. Similarly, the axial length dimension
.alpha. is limited by the need to accommodate the axial length of
the driven magnet 26 and hence the stator 32, the PCB 36 and other
necessary electronic circuitry thereon, the one or more sensors 42
and/or the fitting 44, and the electrical-connector housing 38.
Thus, the aspect ratio of the enclosure 34 is generally limited to
between approximately 0.25 and 1, depending upon the dimensions and
orientation of the components that must be accommodated.
[0037] For example, the axial length dimension .alpha. can be
reduced by configuring the pump-driver enclosure 34 such that the
hydraulic fitting 44 extends through a distal-end wall 48 of the
pump-driver enclosure 34, or by configuring the
electrical-connector housing 38 with an angular (e.g.,
right-angular) bend. Desirably, the aspect ratio can be between
approximately 0.4 and 0.7, as shown in FIGS. 3A and 3B,
respectively. Most desirably, the aspect ratio can be approximately
0.5 or less, as shown in FIGS. 4-5.
[0038] In alternative embodiments the pump-driver enclosure 34 is
not cylindrical, but rather has a different shape with sufficient
interior volume to accommodate the components necessary to operate
the pump assembly. For example, the pump-driver enclosure 34 could
be square or rectangular, and could have an aspect ratio defined by
the expression .alpha./.beta., where .alpha. is an axial dimension
and .beta. is a transverse dimension.
[0039] Although the foregoing embodiments include one or more
sensors for sensing pump parameters (such as temperature, pressure,
etc.) and/or Hall sensors 60 for sensing rotation of the driven
magnet 26, alternative embodiments need not include such sensors or
include any sensors at all. For example, it is possible to use
brushless direct current (BLDC) motor controllers wherein the
stator is driven by a circuit that does not require Hall sensors.
Similarly, depending upon the requirements of the OEM system into
which the integrated-drive pump assembly 10 is incorporated, the
pump assembly need not include any parameter-sensing. However, in
such alternative embodiments, the distal-end wall 30 of the magnet
cup 28 remains exposed, thereby preserving the ability to mount
sensors on the distal-end wall 30.
[0040] The range of candidate pump-heads is not limited to gear
pumps. Exemplary alternative types of pump-head, without intending
to be limiting, are valved or valveless piston pumps. A valveless
piston pump is disclosed in, for example, U.S. Patent Publication
No. 2007-0237658, incorporated herein by reference. See
particularly FIG. 11 of this reference and accompanying discussion
on pages 9-14 thereof.
[0041] Reference is now made to FIG. 8, depicting a portion of a
piston pump-head 200, including a piston 212, a housing 214, a
liner 216, an inlet port 228, and an outlet port 230. The piston
212 is coupled to a driven magnet (not shown). As the magnet
rotates as described above, the piston 212 moves in a reciprocating
manner (arrows 222) in a bore 224 defined in the housing 214.
[0042] Another aspect of this disclosure pertains to hydraulic
circuits comprising a pump such as any of those described above. An
embodiment of a circuit 100 is shown in FIG. 9, which includes a
pump and pressure sensor 102 having an inlet 104 and an outlet 106.
The pump and pressure sensor 102 can be as denoted by the pump
assembly 10 described hereinabove, or any other embodiment. The
inlet 104 is situated downstream of a filter 108, which is situated
downstream of a tank 110 serving as a reservoir for liquid to be
pumped by the pump 102. The outlet 106 is hydraulically connected
to a downstream injector 112 or other component from which pumped
liquid is discharged from the circuit. If desired, the circuit 110
can include a return line 114 for returning liquid to the tank 100
that is not actually discharged from the injector 112.
[0043] It will be understood that this disclosure is directed not
only to pump assemblies including pump head, stator, and pump
driver, but also to "pump-driver" assemblies comprising the stator
mounted to a PCB to which other electronic components are also
mounted. Both types of assemblies represent convenient OEM-supplied
products.
[0044] In view of the many possible embodiments to which the
principles of the disclosed invention may be applied, one of
ordinary skill in the art will recognize that the illustrated
embodiments are only preferred examples and should not be taken as
limiting the scope of this disclosure. Rather, the spirit and scope
of the invention is defined by the following claims.
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