U.S. patent application number 10/907432 was filed with the patent office on 2006-10-12 for pump and motor assembly.
This patent application is currently assigned to ARIMITSU OF NORTH AMERICA, INC.. Invention is credited to James E. Cook.
Application Number | 20060228233 10/907432 |
Document ID | / |
Family ID | 37083322 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060228233 |
Kind Code |
A1 |
Cook; James E. |
October 12, 2006 |
PUMP AND MOTOR ASSEMBLY
Abstract
A fluid pumping system that includes a motor and a pump, wherein
an output shaft of the motor is directly coupled to an input shaft
of the pump. This coupling between the output shaft of the motor
and the input shaft of the pump may be the primary mechanism for
coupling the motor to the pump. Such a configuration may be called
a "floating pump mount", because the pump is primarily coupled to
the motor via the shaft connection. As a result of this connection,
the output shaft of the motor may be naturally "aligned" with the
input shaft of the pump. To help prevent the pump from freely
rotating with the output shaft of the motor during operation, a
rotational stop mechanism may be provided. The rotational stop
mechanism may include at least one resilient member for absorbing
or substantially absorbing at least some of any relative movement
between the pump and the motor.
Inventors: |
Cook; James E.; (Anoka,
MN) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
1221 NICOLLET AVENUE
SUITE 800
MINNEAPOLIS
MN
55403-2420
US
|
Assignee: |
ARIMITSU OF NORTH AMERICA,
INC.
13915-H Radium Street NW
Anoka
MN
|
Family ID: |
37083322 |
Appl. No.: |
10/907432 |
Filed: |
March 31, 2005 |
Current U.S.
Class: |
417/360 |
Current CPC
Class: |
F04B 53/16 20130101;
F04B 17/03 20130101 |
Class at
Publication: |
417/360 |
International
Class: |
F04B 35/00 20060101
F04B035/00 |
Claims
1. A pump assembly, comprising: a motor having a rotating output
shaft, and an output shaft bearing; a pump having a rotating input
shaft, and an input shaft bearing; the input shaft of the pump
being directly coupled to the output shaft of the motor so that the
input shaft of the pump and the output shaft of the motor are fixed
relatively to one another and prevent the pump and the motor from
moving away from each other during operation; the spacing between
the output shaft bearing and the input shaft bearing being less
than 2.0 inch.
2. The pump assembly of claim 1 wherein the spacing between the
output shaft bearing and the input shaft bearing is less than 1.0
inch.
3. The pump assembly of claim 1 wherein the spacing between the
output shaft bearing and the input shaft bearing is less than 0.5
inch.
4. The pump assembly of claim 2 wherein the input shaft of the pump
includes a hollow shaft portion having an output shaft receiving
lumen that extends from a first end of the input shaft and along at
least part of the length of the input shaft, the input shaft
receiving lumen adapted for receiving at least part of the output
shaft of the motor.
5. The pump assembly of claim 2 wherein the input shaft has a key
slot along at least part of the output shaft receiving lumen
length, and the output shaft has a mating key member.
6. The pump assembly of claim 2 wherein the input shaft has a key
member along at least part of the output shaft receiving lumen
length, and the output shaft has a mating key slot.
7. The pump assembly of claim 2 further having a set screw
extending through a side wall of the input shaft and into the
output shaft receiving lumen.
8. The pump assembly of claim 2, wherein the output shaft receiving
lumen has an inner dimension that decreases away from the first end
of the input shaft.
9. The pump assembly of claim 2 wherein the input shaft has a
second end that extends out a side of the pump, the second end
having a solid shaft without an output shaft receiving lumen.
10. A method for removing a pump from a pump assembly, wherein the
pump assembly includes a motor that drives a pump, and the motor
has a rotating output shaft that is directly coupled to a rotating
input shaft of the pump, and wherein the pump is prevented from
rotating freely with respect to the motor by a bracket, wherein the
bracket provides a coupling between the pump and the motor with at
least one resilient member situated between the bracket and the
motor and/or the bracket and the pump when the output shaft of the
motor is engaged with the input shaft of the pump, and the bracket
does not provide a coupling between the bracket and the motor
and/or the bracket and the pump when the output shaft of the motor
is moved away and disengaged from the input shaft of the pump, the
method comprising: loosening the coupling between the output shaft
of the motor and the input shaft of the pump; and pulling the pump
away from the motor until the input shaft of the pump is disengaged
from the output shaft of the motor and until the bracket no longer
provides a coupling between the pump and the motor.
11. The method of claim 10 further comprising the step of: removing
a pin that allows the pump to be pulled away sufficiently far so
that the bracket no longer provides a coupling between the pump and
the motor.
12. The method of claim 10 wherein the loosing step includes
loosing a set screw.
13. A method for removing a pump from a pump assembly, wherein the
pump assembly includes a motor having a rotating output shaft, a
pump having an input shaft that is directly coupled to the output
shaft of the motor, wherein the coupling between the input shaft of
the pump and the output shaft of the motor being the primary
mechanism for preventing the pump and the motor from moving away
from each other during operation, one or more resilient members
extending from the pump toward the motor, and the motor having an
input face that faces but is spaced from the pump, wherein the
input face has one or more depressions or recesses for receiving
the one or more resilient members when the input shaft of the pump
is coupled to the output shaft of the motor, the method comprising
the steps of: loosening the coupling between the output shaft of
the motor and the input shaft of the pump; and pulling the pump
away from the motor until the input shaft of the pump is disengaged
from the output shaft of the motor.
14. A pump assembly, comprising: a pump having a rotating input
shaft, wherein the input shaft of the pump includes a hollow shaft
portion having an output shaft receiving lumen that extends from a
first end of the input shaft and along at least part of the length
of the input shaft, the output shaft receiving lumen having an
inner dimension that decreases away from the first end of the input
shaft; a motor having a rotating output shaft with a shaft end, the
shaft end having a tapered profile to match or substantially match
the inner dimension of the output shaft receiving lumen; the output
shaft of the motor further having a step to a reduced diameter, the
step being spaced from the first end of the input shaft by a
distance when the output shaft of the motor is fully engaged with
the output shaft receiving lumen.
15. The pump assembly of claim 14 wherein the step is spaced from
the first end of the input shaft by a distance of less than 1/4
inch.
16. The pump assembly of claim 15 wherein the step is spaced from
the first end of the input shaft by a distance greater than 1/16
inch but less than 1/4 inch.
17. A method for removing a pump from motor, wherein the pump
includes a rotating input shaft with a hollow shaft portion having
an output shaft receiving lumen that extends from a first end of
the input shaft of the pump and along at least part of the length
of the input shaft, wherein the output shaft receiving lumen has an
inner dimension that decreases away from the first end of the input
shaft, and the motor includes a rotating output shaft with a shaft
end, wherein the shaft end has a tapered profile to match or
substantially match the inner dimension of the output shaft
receiving lumen, and wherein the output shaft of the motor further
has a step to a reduced diameter, wherein the step is spaced from
the first end of the input shaft of the pump by a distance when the
output shaft of the motor is fully engaged with the output shaft
receiving lumen, the method comprising: inserting a wedge in the
space between the step and the first end of the input shaft of the
pump; and pivoting or striking the wedge to release the output
shaft of the motor from the output shaft receiving lumen.
18. The method of claim 17, wherein the wedge is a screw driver or
the like.
19. A pump assembly comprising: a pump having a housing; a shaft
for driving the pump, the shaft having a first end that extends out
of a first side of the pump housing and a second end that extends
out of a second opposite side of the pump housing, the first end of
the shaft having a hollowed out shaft adapted to receive a drive
shaft of a motor.
20. The pump assembly of claim 19 wherein the second end of the
shaft does not include a hollowed out shaft adapted to receive a
drive shaft of a motor.
21. The pump assembly of claim 19 wherein the second end of the
shaft also includes a hollowed out shaft adapted to receive a drive
shaft of a motor.
22. The pump assembly of claim 19 wherein the pump housing is
adapted to receive a removable cover that covers at least part of
the first end of the shaft.
23. The pump assembly of claim 19 wherein the pump housing is
adapted to receive a removable cover that covers at least part of
the second end of the shaft.
24. The pump assembly of claim 19 wherein the pump housing is
adapted to receive a removable cover that entirely covers one end
of the shaft.
25. The pump assembly of claim 19 wherein the second end of the
shaft is adapted to receive a pulley.
Description
FIELD
[0001] The present invention generally relates to the field of
pumps, and more particularly, to pumps that are driven by a motor
such as an internal combustion engine, a hydraulic motor or an
electric motor.
BACKGROUND
[0002] Fluid pumping systems are currently used in a wide variety
of applications. In some cases, the fluid pumping systems include a
pump head that is driven by a rotary motor, such as an internal
combustion engine, a hydraulic motor or an electric motor. When
driven by the motor, the pump head often produces a pressurized
fluid stream that can be used in any number of applications. One
illustrative application is that of a high pressure washing device.
High pressure washing devices typically deliver a fluid such as
water under relatively high pressure to a surface to be cleaned,
stripped or prepared for other treatment. Such pressure washers are
produced in a variety of designs and can be used to perform
numerous functions in industrial, commercial and home
applications.
[0003] Fluid pumping systems can be either stationary or portable.
Stationary fluid pumping systems are generally used in industrial
or commercial applications such as in car washes, manufacturing
facilities, or the like. Portable fluid pumping systems may include
a motor/pump unit that can be carried or wheeled from place to
place.
[0004] In some cases, fluid pumping systems use a piston pump
having one or more reciprocating pistons for delivering liquid
under pressure to the pump outlet. Such piston pumps often have two
or more pistons to provide a generally more continuous pressure,
higher flow rate, and greater efficiency. Multiple piston pumps
often use articulated pistons, or may use a swash plate and linear
pistons for pumping the liquid. Other pump designs may also
exist.
[0005] In many cases, power from the motor is transferred to the
rotating input shaft of the pump via one or more belts, gears, or
the like. However, the use of belts, gears or the like can consume
significant energy, thereby reducing the power that is actually
delivered and available to the pump. Thus, to achieve a desired
pumping capacity, the motor may have to be driven harder, or a
larger motor may have to be provided. This can increase the cost of
operating the fluid pumping system. In addition, the use of belts,
gears or the like can require significant maintenance, which may
also increase the cost of operating the fluid pumping system.
[0006] One approach to overcome some of these limitations is to
drive the rotating input shaft of the pump directly from the
rotating drive shaft of the motor. In some cases, both the motor
and the pump are attached to a common substrate with the rotating
drive shaft of the motor connected directly to the rotating input
shaft of the pump. However, in such systems, the mechanical
alignment of the shafts, and the ease with which such alignment may
be obtained, are of particular concern. The driving and driven
shafts may be said to be perfectly aligned when their axes of
rotation are coincident with one another at all times. Such perfect
alignment would be ideal, but it is often difficult to achieve. In
addition, such shaft misalignments can be static and/or transient.
As a practical matter, it is not very economical to hold machining
tolerances so closely that shaft misalignments are not of a
concern. Shaft misalignment can increase vibration, consume energy,
degrade motor and/or pump performance, increase operating noise,
accelerate wear and tear as well as have other detrimental
effects.
SUMMARY
[0007] The present invention provides a fluid pumping system or
assembly that includes a motor and a pump. An output shaft of the
motor is directly coupled to an input shaft of the pump. In one
illustrative embodiment, the output shaft of the motor is directly
coupled to the input shaft of the pump in such a way that prevents
the pump and the motor from moving away from each other during
operation, and in some cases, is the primary mechanism for coupling
the pump to the motor. Such a configuration may be called a
"floating pump mount", because the pump is primarily coupled to the
motor via the shaft connection. As a result of this connection, the
output shaft of the motor may be naturally "aligned" with the input
shaft of the pump. There may be some relative movement between the
pump and motor housings caused by shaft irregularities, but this
relatively movement does not produce the same detrimental effects
as a shaft misalignment.
[0008] To help prevent the pump from freely rotating with the
output shaft of the motor during operation, a rotational stop
mechanism may be provided. In addition to preventing the pump from
freely rotating with the output shaft of the motor, the rotational
stop mechanism may provide at least one resilient member for
absorbing or substantially absorbing at least some of the relative
movement between the pump and the motor. In some illustrative
embodiments, the rotational stop mechanism may include a bracket
that is coupled between the pump and the motor housings. The at
least one resilient member may be situated between the bracket and
the motor and/or the bracket and the pump. In some embodiments, the
bracket may be adapted to not significantly prevent the pump and
motor from moving away from each other during operation. Instead,
and as noted above, the coupling between the pump input shaft and
the motor output shaft may provide the primary mechanism for
preventing the pump and motor from moving away from each other
during operation. Such a configuration may help keep the output
shaft of the motor naturally "aligned" with the input shaft of the
pump, while allowing some movement between the motor and pump
housings while at the same time preventing the pump from freely
rotating with the output shaft of the motor during operation.
[0009] To help reduce the downward torque on the drive shaft of the
motor caused by the weight of the pump, it may be beneficial to
reduce the distance that the pump is spaced from the motor. In some
embodiments, the motor may have a rotating output shaft with an
output shaft bearing, and the pump may have a rotating input shaft
with an input shaft bearing. As noted above, the input shaft of the
pump may be directly coupled to the output shaft of the motor so
that the input shaft of the pump and the output shaft of the motor
are fixed relatively to one another to prevent the pump and the
motor from moving away from each other during operation. To reduce
the downward torque on the motor drive shaft, the spacing between
the output shaft bearing of the motor and the input shaft bearing
of the pump may be, for example, less than 2.0 inches, less than
1.0 inches, or less than 0.5 inches.
[0010] To help set or release the coupling, some embodiments may
include a set screw in the space between the bearings. The set
screw may be used to loosen and/or tighten the coupling between the
input shaft of the pump and the output shaft of the motor. For
example, to remove the pump from the motor, the set screw may be
loosened to loosen the coupling between the output shaft of the
motor and the input shaft of the pump. The pump may then be pulled
away from the motor until the input shaft of the pump is disengaged
from the output shaft of the motor. When a bracket is provided, the
pump may be pulled sufficiently far away from the motor so that the
bracket also no longer provides any anti-rotational coupling
between the pump and the motor. In some cases, a safety pin may be
provided, which once removed, may allow the pump to be pulled
sufficiently far away so that the bracket no longer provides any
coupling between the pump and the motor.
[0011] The above summary is not intended to describe each disclosed
embodiment or every implementation of the present invention. The
Figures and the detailed description which follow more particularly
exemplify illustrative embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic perspective view of a pump assembly in
accordance with an illustrative embodiment of the present
invention;
[0013] FIG. 2 is a side view of the illustrative pump assembly of
FIG. 1;
[0014] FIG. 3 is a front view of an illustrative rotational stop
mechanism that may be used to help prevent the pump from freely
rotating with the output shaft of the motor during operation;
[0015] FIG. 4 is a side view of the illustrative rotational stop
mechanism of FIG. 3;
[0016] FIG. 5 includes a side view and front view of an
illustrative resilient member that may be used to absorb or
substantially absorb at least some of the relative movement between
the pump and the motor;
[0017] FIG. 6 is an assembly view of an illustrative piston pump
that is suitable for use with the present invention;
[0018] FIG. 7 is a partial cross-sectional side view of an
illustrative connection between the motor output shaft and pump
input shaft of FIG. 1;
[0019] FIG. 8 is a partial cross-sectional side view of another
illustrative connection between the motor output shaft and pump
input shaft of FIG. 1;
[0020] FIG. 9 is a schematic side view of a pump assembly in
accordance with another illustrative embodiment of the present
invention;
[0021] FIG. 10 is a schematic side view of a pump assembly in
accordance with yet another illustrative embodiment of the present
invention;
[0022] FIG. 11 is a schematic partial-cut away side view of a pump
assembly in accordance with yet another illustrative embodiment of
the present invention; and
[0023] FIG. 12 is an assembly view of an illustrative piston pump
that includes an input shaft that has a hollow shaft end and a
solid shaft end extending out of the pump housing.
DETAILED DESCRIPTION
[0024] The following detailed description should be read with
reference to the drawings. The drawings, which are not necessarily
to scale, depict illustrative embodiments and are not intended to
limit the scope of the invention.
[0025] FIG. 1 is a schematic perspective view of a pump assembly in
accordance with an illustrative embodiment of the present
invention. FIG. 2 is a side view of the illustrative pump assembly
of FIG. 1. The illustrative pump assembly is generally shown at 10,
and includes a motor 12 and a pump 14. The motor 12 may be any type
of motor that includes a rotating output shaft 20 including, for
example, an internal combustion engine, a hydraulic motor or an
electric motor. The pump 14 may be any type of pump that includes a
rotating input shaft 22. The illustrative pump 14 has a pump inlet
16 and a pump output 18.
[0026] As best shown in FIG. 2, the output shaft 20 of the motor 12
is directly coupled to the input shaft 22 of the pump 14. In some
illustrative embodiments, the input shaft 22 of the pump 14 may
have a hollow shaft end portion that has an output shaft receiving
lumen for receiving the output shaft 20 of the motor 12. The input
shaft 22 of the pump 14 may also have a key slot (not shown) that
extends along at least part of the output shaft receiving lumen,
and the output shaft 20 of the motor 12 may have a mating key
member (not shown). Alternatively, or in addition, the input shaft
22 of the pump 14 may have a key member (not shown) along at least
part of the output shaft receiving lumen, and the output shaft 20
of the motor 12 may have a mating key slot.
[0027] To help set or release the coupling between the input shaft
22 of the pump 14 and the output shaft 20 of the motor 12, and in
some embodiments, a set screw 24 may extend through a side wall of
the input shaft 22 and into the output shaft receiving lumen. The
set screw 24 may engage the output shaft 20 of the motor 12, and
when tightened, may secure the connection so that pump 14 is
prevented from moving away from the motor 12, and visa-versa,
during operation. Such a configuration may be called a "floating
pump mount", because the pump 14 is primarily coupled to the motor
12 via the shaft connection. As a result of this connection, the
output shaft 20 of the motor 12 may be naturally "aligned" with the
input shaft 22 of the pump 14. There may be some relative movement
between the pump 14 and motor 12 housings caused by shaft
irregularities, but this relatively movement does not produce the
same detrimental effects as a shaft misalignment.
[0028] To help prevent the pump 14 from freely rotating with the
output shaft 20 of the motor 12 during operation, a rotational stop
mechanism may be provided. One illustrative rotational stop
mechanism is generally shown at 28, and includes a bracket 30 that
is coupled between the pump 14 and the motor 12 housings. The
bracket 30 is shown bolted or otherwise secured to the housing of
the pump 14, such as by bolt 32. The motor 12 includes a number of
shafts or studs 34a-34b extending out from the motor face 38, and
the bracket 30 includes a number of corresponding holes 36 (see
FIG. 3) for receiving the studs 34a-34b. The holes 36 may be sized
sufficiently large so that a grommet 38 or other resilient member
may be placed in the hole and between the studs 34a-34b and the
bracket 30. Thus, in addition to preventing the pump 14 from freely
rotating with the output shaft 20 of the motor 12, the bracket 30
and accompanying holes and grommets 38, may absorb or substantially
absorb at least some of the relative movement between the pump 14
and the motor 12. In this illustrative embodiment, the bracket 30
and grommets 38 merely slide over the studs 34a-34b, and therefore
do not significantly prevent the pump 14 and motor 12 from moving
away from each other during operation. Instead, and as noted above,
the connection between the pump input shaft 22 and the motor output
shaft 20 may provide the primary mechanism for preventing the pump
14 and motor 12 from moving away from each other during operation.
It is believed that such a configuration may help keep the output
shaft 20 of the motor 12 naturally "aligned" with the input shaft
22 of the pump 14, while allowing some movement between the motor
12 and pump 14 housings while at the same time preventing the pump
14 from freely rotating with the output shaft 20 of the motor
during operation.
[0029] In some cases, the pump 14 may present a lateral torque on
the bracket 30 because more of the weight of the pump may be
laterally offset to one side relative to the input shaft 22 of the
pump 14. Because the grommets 38 may tend to deform slightly under
such a lateral torque, even when the pump 14 is not operating, the
holes 36 in the bracket 30 may be positioned to compensate for this
grommet deformity so that the pump is level at rest. In the
illustrative embodiment shown in FIG. 3, the holes 36 are offset
about 1.2 degrees in a clockwise direction about the axis of the
input shaft 22 of the pump 14 to compensate for the expected
deformity in the grommets 38.
[0030] In some cases, one or more of the studs 34a-34b may include
a hole or slot extending in a transverse direction across the stud
34a-34b. A safety pin 40 or other removable mechanical stop may
extend through the hole or along the slot. This may help prevent
the pump 14 from flying away from the motor 12 in the event that
the input shaft 22 of the pump, the output shaft 20 of the motor 12
or the shaft connection should break or otherwise come loose during
operation.
[0031] As detailed above, the set screw 24 may be used to loosen
and/or tighten the coupling between the input shaft 22 of the pump
14 and the output shaft 20 of the motor 12. Thus, and in some
illustrative embodiments, the pump 14 may be easily removed from
the motor 12 by simply loosening the set screw 24, which loosens
the coupling between the output shaft 20 of the motor 12 and the
input shaft 22 of the pump 14. The pump 14 may then be pulled away
from the motor 12 until the input shaft 22 of the pump 14 is
disengaged from the output shaft 20 of the motor 12. When a bracket
30 is provided, such as shown in FIGS. 1-2, the pump 14 may be
pulled sufficiently far away from the motor 12 so that the bracket
30 slides off the end of the studs 34a-34b and no longer provides
any anti-rotational coupling between the pump 14 and the motor 12.
When a safety pin 40 is provided, the safety pin 40 may first be
removed, which may allow the bracket 30 to be slid off the end of
the studs 34a-34b.
[0032] It has been found that by providing a direct coupling
between the input shaft 22 of the pump 14 and the output shaft 20
of the motor 12, as well as a rotational stop mechanism with one or
more resilient members interposed between the rotational stop
mechanism and the pump and/or motor, the resulting pump assembly
may produce relative low noise levels when operating.
[0033] FIG. 3 is a front view of an illustrative rotational stop
mechanism that may be used to help prevent the pump from freely
rotating with the output shaft of the motor during operation. FIG.
4 is a side view of the illustrative rotational stop mechanism of
FIG. 3. The rotation stop mechanism shown in FIGS. 3-4 includes a
bracket 30 that extends between the pump 14 and the motor 12. The
illustrative bracket 30 may be bolted or otherwise secured to the
housing of the pump 14, such as by bolt 32 (see FIG. 2). Bolt holes
50a and 50b may be provided in a first flange 52 of the bracket 30
to accept two such bolts 32. A second flange 54 may extend
substantially parallel to the first flange 52, and may be connected
to the first flange 52 by an intermediate leg portion 63, as best
shown in FIG. 4. The second flange 52 may include a number of stud
receiving holes 36 (four are shown), each for accepting a
corresponding stud 34a-34b. The stud receiving holes 36 may be
sized sufficiently large so that a grommet 38 or other resilient
member may be placed in the hole and between the studs 34a-34b and
the bracket 30.
[0034] The bracket 30 may also include a shaft receiving hole 58
for allowing the shaft of the pump 14 and/or the shaft of the motor
12 to pass through the bracket 30. In some embodiments, the bracket
30 may also include one or more accessory mounting holes, such as
accessory mounting holes 60 and 62. Accessory mounting holes 60 and
62 may be adapted to accept and mount one or more accessories to
the bracket 30, such as a pressure gauge, a valve or any other
suitable accessory, as desired.
[0035] FIG. 5 includes a side view and front view of an
illustrative resilient member that may be used to absorb or
substantially absorb at least some of the relative movement between
the pump and the motor. In the illustrative embodiment, the
resilient member is shown as a rubber grommet 38a. However, it is
contemplated that any suitable resilient member may be used, and
may be formed from any suitable material, as desired.
[0036] The illustrative grommet 38a includes a first side member 70
joined to second side member 72 by a reduced diameter central
member 74. When installed, the reduced diameter central member 74
may be situated in one of the holes 36 of the bracket 30 (see, for
example, FIG. 2), with the first side member 70 overlapping one
side of the bracket 30 and the second side member 72 overlapping
the opposite side of the bracket 30. The first side member 70 and
the second side member 72 may tend to hold the grommet 38a in
place. The illustrative grommet 38a includes a central hole or bore
80 that is adapted to receive a corresponding one of the studs 34b.
The grommet 38a may absorb or substantially absorb at least some of
the relative movement between the pump and the motor. It is
contemplated that, in some embodiments, a grommet similar to that
shown in FIG. 5 may be installed in each of the holes 36 of the
bracket of FIG. 3.
[0037] FIG. 6 is an assembly view of an illustrative piston pump 14
that is suitable for use with the present invention. The pump shown
in FIG. 6 is similar to a pump that is commercially available from
Arimitsu of North America, located in Ramsey, Minn. However, the
input drive shaft 92 shown in FIG. 6 has been modified to include a
hollow shaft portion 93 that is adapted to receive an output shaft
of a motor, as further described herein.
[0038] The illustrative piston pump includes a pump housing 90 that
receives the input shaft 92. A first side bearing 94 and a second
side bearing 96 are provided to support the input shaft 92 in the
pump housing 90, and allow the input shaft 92 can freely rotate in
the pump housing 90. A seal 97 and cover 98 provide protection and
support to bearing 94. Likewise, a seal 99 and cover 100 provide
protection and support to bearing 94.
[0039] The particular pump 14 shown in FIG. 6 includes three
pistons, including a piston 102. The pistons are driven in a
reciprocating fashion as the input shaft 92 is rotated, which
produces a pumping action between the input port 16 and the output
port 18. The housing 90 may be at least partially filled with oil
or other lubricant during operation to help lubricate the various
components therein. In some cases, it is desirable to keep the pump
housing 90 fairly level during operation so that the oil or other
lubricant can properly lubricate all of the desired components in
the pump.
[0040] FIG. 7 is a partial cross-sectional side view of an
illustrative connection between the motor output shaft 20 and the
pump input shaft 22 of FIG. 1. As can be seen, and in the
illustrative embodiment, the pump input shaft 22 includes a hollow
shaft portion 93 that extends from the end of the input shaft 22
for a distance. The hollow shaft portion 93 has an output shaft
receiving lumen for receiving the output shaft 20 of the motor 12.
The input shaft 22 of the pump 14 may have a key slot (not shown)
that extends along at least part of the output shaft receiving
lumen, and the output shaft 20 of the motor 12 may have a mating
key member (not shown). Alternatively, or in addition, the input
shaft 22 of the pump 14 may have a key member (not shown) along at
least part of the output shaft receiving lumen, and the output
shaft 20 of the motor 12 may have a mating key slot.
[0041] To help set or release the coupling between the input shaft
22 of the pump 14 and the output shaft 20 of the motor 12, and in
some embodiments, a set screw 24 may extend through a side wall of
the input shaft 22 and into the output shaft receiving lumen. The
set screw 24 may engage the output shaft 20 of the motor 12, and
when tightened, may secure the connection so that pump 14 is
prevented from moving away from the motor 12, and visa-versa,
during operation. Such a configuration may be called a "floating
pump mount", because the pump 14 is primarily coupled to the motor
12 via the shaft connection. As a result of this connection, the
output shaft 20 of the motor 12 may be naturally "aligned" with the
input shaft 22 of the pump 14. There may be some relative movement
between the pump 14 and motor 12 housings caused by shaft
irregularities, but this relatively movement does not produce the
same detrimental effects as a shaft misalignment.
[0042] To help reduce the downward torque on the drive shaft 20 of
the motor 12 caused by the weight of the pump 14 in such a
"floating mount configuration", it may be beneficial to reduce the
distance "D" 108 between the pump 14 and the motor 12. In some
embodiments, the output shaft 20 of the motor 12 may be supported
by an output shaft bearing 110, and the input shaft 22 of the pump
14 may be supported by an input shaft bearing 96. In some
embodiments, the direct connection between the output shaft 20 of
the motor 12 and the input shaft 22 of the pump 14 may allow the
spacing between the output shaft bearing 110 of the motor 12 and
the input shaft bearing 96 of the pump 14 to be, for example, less
than 2.0 inches, less than 1.0 inches, or less than 0.5 inches. By
reducing the downward torque, the wear and tear on the output shaft
bearing 110 of the motor 12 may be reduced.
[0043] When a set screw 24 is provided, the set screw 24 may be
positioned in the space between the bearings 110 and 96, which in
some cases, may allow the set screw 24 to be accessed and
manipulated by the user of the pump assembly. As noted above, the
set screw 24 may be used to loosen and/or tighten the coupling
between the input shaft 22 of the pump 14 and the output shaft 20
of the motor 12.
[0044] FIG. 8 is a partial cross-sectional side view of another
illustrative connection between the motor output shaft and pump
input shaft of FIG. 1. This illustrative embodiment is similar that
shown in FIG. 7, except that the hollow shaft portion 93 of the
input shaft 22 of the pump 14 has a tapered diameter along its
length. That is, the output shaft receiving lumen of the input
shaft 22 of the pump 14 may have an inner dimension that decreases
away from the end of the input shaft 22. In some cases, this may
make it easier to remove the output shaft 20 of the motor 12 from
the output shaft receiving lumen after securing mechanism
therebetween is loosened.
[0045] In the illustrative embodiment, the securing mechanism
between the output shaft 20 of the motor 12 and the input shaft 22
of the pump 14 includes a bolt 112. The bolt 112 extends down the
center of the input shaft 22 of the pump 14 and is threaded into
the distal end of the output shaft 20 of the motor 12. This may
help secure the input shaft 22 of the pump 14 to the output shaft
22 of the motor 12. While a bolt 112 is shown in FIG. 8, it is
contemplated that the input shaft 22 of the pump 14 may be
selectively secured to the output shaft 22 of the motor 12 by any
suitable securing mechanism, including the use of a set screw, as
desired.
[0046] In some embodiments, and to further aid in the separation
between the output shaft 20 of the motor 12 and the input shaft 22
of the pump 14, the output shaft 20 of the motor 12 may include a
step 115 to a reduced diameter, which is spaced slightly from the
end of the input shaft 22 of the pump 14 when the input shaft 22 of
the pump 14 is fully engaged with the output shaft 22 of the motor
12. The space may be, for example, in the 1/16 to 1/4 inch range,
but other spacing may also be used. Once the bolt 115 is removed, a
screw driver or the like may be inserted into the space between the
step 115 and the end of the input shaft 22 of the pump 14, and
pivoted or struck with a hammer to help release the output shaft 20
of the motor 12 from the output shaft receiving lumen of the input
shaft 22 of the pump. It is contemplated that the configuration of
the input shaft of the pump and the output shaft of the motor as
described above may be reversed. That is, and in some embodiments,
the motor may include a tapered hollow shaft end, and the pump may
include a tapered input shaft end along with a step that is spaced
slightly from the end of the motor shaft when the pump shaft is
fully engaged with the motor shaft, if desired.
[0047] FIG. 9 is a schematic side view of a pump assembly 140 in
accordance with another illustrative embodiment of the present
invention. This illustrative embodiment is similar to that
described above, except that the bracket 30 is replaced with a
different bracket 150 configuration. A first flange 160 of bracket
150 is shown bolted to motor housing 12 by bolt 162. In some
embodiments, the first flange 162 may be bolted or otherwise
attached to the mounting feet of the motor 12, or any other
suitable location. It is contemplated that rather than rigidly
attaching the first flange 162 to the motor housing 12, a resilient
member may be interposed between the first flange and the motor
housing, if desired.
[0048] To help prevent the pump 14 from freely rotating with the
output shaft 20 of the motor 12 during operation, a second flange
156 of bracket 150 may be coupled to the pump 14. In the
illustrative embodiment, a post or stud 152 may extend from the
pump housing 14. A hole may be provided in the second flange 156
that receives the post or stud 152. A resilient member, such as a
grommet 158, may be positioned in the hole to absorb or
substantially absorb at least some of the relative movement between
the pump 14 and the motor 12.
[0049] FIG. 10 is a schematic side view of a pump assembly 178 in
accordance with yet another illustrative embodiment of the present
invention. In this illustrative embodiment, a pump 180 includes a
pump housing that has a bracket like portion 182. The bracket like
portion 182 may be molded with the reminder of the pump housing, or
may be separately formed and attached to the pump housing. In the
illustrative embodiment, the bracket like portion 182 includes one
or more holes. The one or more holes may be adapted to receive one
or more studs from the motor housing 12, as well as a grommet or
the like similar to that discussed above. For example, and as shown
in FIG. 10, a threaded rubber grommet 192 may be used. The threaded
rubber grommet 192 may include, for example, two metal threaded
mounting holes, one on each side. A rubber plug, bobbin or other
resilient member may be interposed therebetween. One of the
threaded mounting holes may be threaded or otherwise attached to
the end of a stud, such as stud 188, that extends from the motor
12. The other threaded mounting hole may be threaded or otherwise
attached to a bolt 194 or the like that extends through one of the
holes in bracket like portion 182. A nut 193 may then be tightened
onto the bolt 194 to secure the connection. The threaded rubber
grommet 192 may provide a resilient connection between each of the
studs 188 and the pump housing.
[0050] FIG. 11 is a schematic partial-cut away side view of a pump
assembly 200 in accordance with yet another illustrative embodiment
of the present invention. The pump 180 is similar to that shown and
described above with respect to FIG. 10, and includes a pump
housing with a bracket like portion 182. The bracket like portion
182 includes one or more holes. In this illustrative embodiment,
one or more resilient members, such as resilient members 204a and
204b, are secured to the bracket like portion 182 and extend away
from the pump housing and toward the motor 202. The motor housing
of the motor 202 has a front face 206 with depressions or recesses
208a and 208b that may match the shape and are adapted to receive
the resilient members 204a and 204b. A space is provided between
the motor housing and the bracket like portion 182 so that there is
no direct contact therebetween (other than through the resilient
members 204a and 204b). The resilient members 204a and 204b may
provide a resilient connection between the motor 202 and the pump
180.
[0051] FIG. 12 is an assembly view of an illustrative piston pump
228 that includes an input shaft 230 that has a hollow shaft end
231 and a solid shaft end 232, each extending out of a respective
end of the pump housing 234. In some cases, the input shaft 230 may
have a hollow shaft end and both ends, if desired. In the
illustrative embodiment of FIG. 12, the hollow shaft end 231 is
adapted to receive an output shaft of a motor, as further described
herein, and the solid shaft end 232 is not adapted to receive an
output shaft of a motor, but rather is adapted to be selectively
connected to a pulley, gear or other accessory. A cover 236 may be
provided to cover either the solid shaft end 232 or the hollow
shaft end 231, when either is not currently in use.
[0052] Such a configuration may allow the pump to be more easily
adapted to different pump assembly configurations. For example,
when a motor that includes a solid shaft is used to directly drive
the pump 228, the output shaft of the motor may be received by a
shaft receiving lumen 233 of the hollow shaft end 231, as described
above. In those applications where the pump is to be driven by a
pulley, gear or other accessory, a pulley, gear or other accessory
may be mounted to the solid shaft end 232. The solid shaft end 232
may have one or more threaded holes or the like to aid in securing
a pulley, gear or other accessory, but in the illustrative
embodiment, it is not a "hollow" shaft in the sense that it is
adapted to receive an output shaft of a motor. The cover 236 may be
provided over whichever shaft end is currently not in use.
[0053] In some cases, a shaft cover such as shaft cover 237, may be
provided over the shaft end that is currently in use. The shaft
cover 237 may include a hole 239 through the housing to allow the
shaft end 231 to extend therethrough. The shaft cover 237 may
provide additional safety by helping to prevent a user from coming
into contact with at least part of the spinning shaft end 231.
[0054] In some cases, the shaft 230 may be removed from the pump
housing 234 and reversed in position, so that the hollow shaft end
231 extends out of the pump housing 234 in a leftward direction in
FIG. 12, and the solid shaft end 232 extends out in a rightward
direction. This may further increase the flexibility in mounting
the pump 228 in different pump assembly configurations.
[0055] Those skilled in the art will recognize that the present
invention may be manifested in a variety of forms other than the
specific embodiments described and contemplated herein.
Accordingly, departures in form and detail may be made without
departing from the scope and spirit of the present invention as
described in the appended claims.
* * * * *