U.S. patent application number 11/504756 was filed with the patent office on 2008-02-21 for high pressure pump, frame and housing assembly.
Invention is credited to Stephen J. Laski.
Application Number | 20080044298 11/504756 |
Document ID | / |
Family ID | 39101560 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080044298 |
Kind Code |
A1 |
Laski; Stephen J. |
February 21, 2008 |
High pressure pump, frame and housing assembly
Abstract
The invention is a high pressure pump, frame and housing
assembly including a high pressure pump, electric motor, belt
drive, metal frame, plastic housing and noise absorbing sheets that
combine to suppress vibration, attenuate noise and allow viewing of
the motorized pump assembly. The motorized pump produces a flow
rate of at least 4 gpm at a pressure of at least 2,000 psi, while
the assembly keeps the noise level at or below about 77 decibels.
Vibrations are suppressed by the frame and housing which are formed
by irregularly shaped and sized frame members, segments and panels.
The housing panels combine with the porous noise attenuating sheets
to form dead zones for absorbing noise. The sheets and dead zones
are compactly arranged inside the frame segments. Two transparent
panels form dual opposed windows for lighting and viewing the
active internal components.
Inventors: |
Laski; Stephen J.; (Howell,
MI) |
Correspondence
Address: |
Jeffrey S. Sokol;Cook & Franke S.C.
660 East Mason Street
Milwaukee
WI
53202
US
|
Family ID: |
39101560 |
Appl. No.: |
11/504756 |
Filed: |
August 15, 2006 |
Current U.S.
Class: |
417/312 ;
417/362 |
Current CPC
Class: |
F04B 17/03 20130101;
F04B 53/16 20130101 |
Class at
Publication: |
417/312 ;
417/362 |
International
Class: |
F04B 39/00 20060101
F04B039/00 |
Claims
1. A high pressure pump, frame and housing assembly with vibration
suppressing, noise attenuating and internal viewing features, said
high pressure pump, frame and housing assembly comprising: a frame
having front, rear, top, bottom and side segments that define an
interior space and lower and upper portions, said lower portion
having a lower platform and said upper portion having an upper
platform, each of said segments being formed by several elongated,
perimeterally aligned, frame members to define a frame segment
opening, at least two of said frame members of each of said
segments have a different length, and said lower portion being
formed by lower frame members having a first cross-sectional shape
and said upper portion being formed by upper frame members having a
second cross-sectional shape, said first cross-sectional shape
being smaller than said second cross-sectional shape; a motorized
pump assembly including a motor, a high pressure pump, and a drive
assembly, said motor having a drive shaft and being adapted to
produce at least 7.5 Hp, said motor being mounted to said lower
platform, said pump having a driven shaft, an inlet port and an
outlet port, and being adapted to produce a flow rate of at least 4
gpm and a discharge pressure of at least 2,000 psi, said pump being
mounted to said upper platform, and said drive assembly including
rotatable drive and driven members, said drive member being fixed
to said shaft of said motor, and said driven member being fixed to
said shaft of said pump, said drive member rotatably driving said
driven member; a housing secured around said frame to enclose said
interior space and said motorized pump assembly, said housing being
formed by a plurality of individual panels, each panel enclosing at
least one frame segment, at least two of said panels being
transparent to form dual opposed windows, one of said windows being
at an angle relative to said other window, each of said windows
allowing ambient light into said interior space to provide
backlighting for said other window, and said windows allowing
viewing of said motor, pump and drive assembly from locations
exterior to said housing during operation of said motorized pump
assembly; a plurality of noise attenuating sheets located in said
frame segment openings, said sheets being shaped for substantially
flush engagement with said frame members forming its said frame
segment opening, said sheets having a main portion spaced a
distance of at least about one to four inches from its said panel
for its said segment to define a dead zone, said dead zone
containing ambient air between its said attenuating sheet and said
housing; and, wherein said motorized pump assembly has a noise
level of below about 77 decibels during operation when measured at
location exterior to said pump, frame and housing assembly.
2. The high pressure pump, frame and housing assembly of claim 1,
and wherein said noise attenuating sheets are thin plastic sheets
that are micro perforated to absorb noise.
3. The high pressure pump, frame and housing assembly of claim 2,
and wherein said noise attenuating sheets have opposed legs that
space its said main portion from said its said panel.
4. The high pressure pump, frame and housing assembly of claim 3,
and wherein said noise insulation has a combined surface area (Sa)
greater than the combined surface area of the interior space of
said assembly (St).
5. The high pressure pump, frame and housing assembly of claim 1,
and wherein said housing substantially completely encloses said
interior space.
6. The high pressure pump, frame and housing assembly of claim 5,
and wherein said one of said dual opposed windows is a vertical
front window that spans from said bottom to said top of said frame,
and said other window is a rear window that is angled relative to
said front window.
7. The high pressure pump, frame and housing assembly of claim 1,
and wherein said pump produces a discharge pressure of between
3,000 and 5,000 psi.
8. The high pressure pump, frame and housing assembly of claim 7,
and wherein said motor is adapted to produce between about 7.5 to
25 Hp, and said pump and motor produce a flow rate of between about
4 to 18 gpm.
9. The high pressure pump, frame and housing assembly of claim 8,
and wherein said motor is an electric motor and said pump is
positive displacement pump.
10. The high pressure pump, frame and housing assembly of claim 1,
and wherein said drive assembly is a pulley and drive belt assembly
drive and driven pulleys, and said drive pulley has a smaller
diameter than said driven pulley.
11. The high pressure pump, frame and housing assembly of claim 1,
and wherein said frame has an ergonomic design that includes legs
to elevate said pump and motor from a supporting surface.
12. The high pressure pump, frame and housing assembly of claim 1,
and wherein said frame includes a centerline, said lower platform
includes a lower plate with a first thickness for securing said
motor, and said upper platform includes an upper plate with a
second larger thickness for securing said pump, said pump and motor
being offset from said centerline.
13. The high pressure pump, frame and housing assembly of claim 1,
and wherein said inlet and outlet of said pump each include a flex
hose, and wherein said motor and pump are mounted on vibration
absorbing pads.
14. A frame and housing assembly with vibration suppressing, noise
attenuating and internal viewing features for a motorized pump
assembly including a motor, a high pressure pump and a pulley drive
assembly, the motor being adapted to produce at least 7.5 Hp, the
pump having inlet and outlet ports and being adapted to produce a
flow rate of at least 4 gpm and a discharge pressure of at least
2,000 psi, and the pulley drive assembly including a drive belt and
rotatable drive and driven pulleys, the drive pulley being fixed to
a shaft of the motor, and the driven pulley being fixed to a shaft
of the pump, and said frame and housing comprising: a frame having
front, rear, top, bottom and side segments that define an interior
space and lower and upper portions, said lower portion having a
lower platform, and the motor being mounted to said lower platform,
and said upper portion having an upper platform, and the pump being
mounted to said upper platform, each of said segments being formed
by several elongated, perimeterally aligned, frame members to
define a frame segment opening, at least two of said frame members
of each of said segments have a different length, and said lower
portion being formed by lower frame members having a first
cross-sectional shape and said upper portion being formed by upper
frame members having a second cross-sectional shape, said first
cross-sectional shape being smaller than said second
cross-sectional shape; a housing secured around said frame to
enclose said interior space and the motorized pump assembly, said
housing being formed by a plurality of individual panels, each
panel enclosing at least one frame segment, at least two of said
panels being transparent to form dual opposed windows, one of said
windows being at an angle relative to said other window, each of
said windows allowing ambient light into said interior space to
provide backlighting for said other window, and said windows
allowing viewing of the motor, pump and pulley drive assembly from
locations exterior to said frame and housing assembly during
operation of the motorized pump assembly; a plurality of noise
attenuating sheets located in said frame segment openings, said
sheets being shaped for substantially flush engagement with said
frame members forming its said frame segment opening, said sheets
having a main portion spaced a distance of at least about one to
four inches from its said panel for its said segment to define a
dead zone, said dead zone containing ambient air between its said
attenuating sheet and said housing; and, wherein the motorized pump
assembly has a noise level of below about 77 decibels during
operation when measured at a location exterior to said frame and
housing assembly.
15. The frame and housing assembly of claim 14 and wherein said
noise attenuating sheets are thin plastic sheets that are micro
perforated to absorb noise.
16. The frame and housing assembly of claim 14, and wherein said
housing substantially completely encloses said interior space.
17. The frame and housing assembly of claim 16, and wherein said
one of said dual opposed windows is a vertical front window that
spans from said bottom to said top of said frame, and said other
window is a rear window that is angled relative to said front
window.
18. The frame and housing assembly of claim 14, and wherein the
motor is an electric motor adapted to produce between about 7.5 to
25 Hp, the pump is a positive displacement pump adapted to produce
a flow rate of between about 4 to 18 gpm and a discharge pressure
of between about 3,000 and 5,000 psi.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to a pump, frame, and housing
assembly for a motorized, high pressure pump producing an output of
at least 4 gpm and 2,000 psi of hydraulic pressure, where the
assembly suppresses motor and pump vibrations, reduces noise to 77
decibels or less, and allows safe viewing of internal components
during operation.
BACKGROUND OF THE INVENTION
[0002] Manufacturing systems and processes that require a source of
high pressure fluid are well known. These systems increase
manufacturing efficiency, reduce waist and improve the quality of
goods. Many of these systems are computer controlled robotic
systems that use a robotic arm to control and aim a high pressure
stream of fluid. Washing, deburring and cutting systems are but a
few examples of the many types of systems that require fluid
pressures of 2,000 psi (pounds per square inch) or greater. Each
year, the various uses and needs for these systems and processes
continues to grow. These manufacturing systems incorporate high
pressure pumps and relatively powerful motors that can pressurize a
working fluid such as water to a desired hydraulic pressure at a
flow rate needed to properly perform the system. Most manufacturing
systems require a flow rate of at least 4 gpm (gallons per minute).
An example of a conventional high pressure pump, electric motor and
frame assembly is shown in FIGS. 1-4.
[0003] A problem with conventional high pressure pump and motor
assemblies is excessive noise. High pressure pumps capable of
producing the required pressures and volumetric flow rates needed
for most manufacturing systems are noisy. The electric motor and
pulley drive assembly only add to this noise level. In many
conventional cases, the noise level of the motorized pump and frame
assembly exceeds 90 decibels. Yet, prolonged exposure to this level
of noise is known to cause hearing loss. This noise level can also
lead to accidents because workers cannot hear each other talk, as
human speech is typically about 75 decibels and is drowned out by
the pumping unit. Workers may also be unable to hear other heavy
equipment or vehicles in the area. Still, locating high pressure
pumping units in remote parts of a plant or constructing a room for
them is costly and often impractical.
[0004] Another problem with conventional high pressure pumps and
motors is vibration. The high rates of speed and cyclical motion of
the pump, motor and drive assembly generate vibrations that shake
their supporting frame and the components attached to that frame.
Industrial high pressure pumps typically take the form of positive
displacement pumps. These pumps generate large pulses of energy and
vibrations each time their piston or pistons are stroked to
pressurize the working hydraulic fluid such as water. The pumps
typically operate at several hundred rotations per minute (rpm).
The electric motors typically used to drive the pumps rotate at
even higher rates of speed. The various cyclical pulses and
rotational vibrations of the motorized pump assembly can combine to
harmonically excite the frame and produce even larger amplitude
vibrations and shaking. These vibrations create excessive wear and
tear on the equipment, can lead to malfunctions, and result in
increased maintenance requirements for the equipment. These
vibrations and shaking of components also increase the level of
noise.
[0005] A still further problem with high pressure pumps and motors
is visibility and lighting. The expensive, high speed equipment
must be routinely inspected to ensure proper operation.
Abnormalities that can lead to the rapid deterioration or
degeneration of the equipment should be easily detected. For
example, periodic visual checks for smoke, excessive shaking, or
loosening or flaking of the drive belt, help indicate if service is
required. Active components such as the motor, pump and drive
assembly should be located where they are not visually obstructed
by other components and are properly illuminated by light so that
any abnormalities can be easily seen. Visibility and proper
lighting are important because even trace amounts of smoke, belt
ware or leaks can lead to rapid deterioration and even dangerous
and costly disintegration of the high speed equipment. Yet, an
acoustic housing that surrounds the active equipment tends to block
visibility and lighting, and renders proper inspection and
maintenance problematic.
[0006] A still further problem with high pressure pump and motor
assemblies is ventilation. High pressure pumps and their motors
need cooling. Using the air in the building to cool the equipment
is common and economical. Higher horsepower electric motors
typically include a fan to draw air into the housing to cool its
internal components and prevent them from overheating. High
pressure pumps also need air flow around them to prevent
overheating. Enclosing a high pressure pump in a sealed housing can
result in overheating, malfunction or reduced life of the pump or
motor unless proper ventilation is provided. Yet, vent openings
provide pathways for transmitting noise, and can render other noise
attenuating methods ineffective.
[0007] A still further problem with high pressure pump and motor
assemblies is safety. The shafts of the motor and pump spin at
several hundred revolutions per minute (rpm). The drive belt and
pulleys that join the drive and driven shafts of the motor and pump
also turn at a high rate of speed. Any worker that inadvertently
comes in contact with these components during operation can be
severely injured. Although some designs include a cabinet that
encloses the pulley and belt as in FIG. 3, this cabinet obstructs
the view of these and other components during operation. The
cabinet also requires workers to come close to the unit, open the
cabinet, and even lean over the high speed components to inspect
them during operation.
[0008] A further problem with motorized, high pressure pump
assemblies is their bulky size. Although floor space in most
manufacturing settings is at a premium, the components are
typically arranged on a skid type frame having a large footprint as
in FIG. 1. The pump, motor and pulley drive are mounted close to
the floor to dampen vibrations and minimize their transmission to
each other, as well as other static components such as the fluid
storage tanks. Designs that rely on the dampening effect of the
floor to reduce vibrations increase the footprint of the unit. The
actively rotating components, as well as other relatively static
components, are simply spread out over the length and width of the
frame. This large footprint also increases the difficulty and cost
of enclosing the components in a housing.
[0009] A still further problem with motorized high pressure pump
assemblies is maintenance. For example, the oil level of the pump
must be routinely checked and maintained. Yet, the frame sets on
the floor and the active components are located near the floor.
Workers must bend over or kneel down, open access doors or remove
obstructions to inspect or perform routine maintenance on various
components. Dirt and debris also collect under the unit which is at
best difficult to clean, particularly during operation. This dirt
and debris can be drawn into the motor or pump and cause damage, or
be picked up by the drive belt and result in unnecessary injury or
damage.
[0010] The present invention is intended to solve these and other
problems.
BRIEF DESCRIPTION OF THE INVENTION
[0011] This invention relates to a high pressure pump, frame and
housing assembly including a high pressure pump, electric motor,
drive belt assembly, metal frame, plastic housing and noise
absorbing sheets that combine to suppress vibration, reduce noise,
and allow viewing of the motorized pump assembly. The motorized
pump produces a flow rate of at least 4 gpm and hydraulic pressure
of at least 2,000 psi, while keeping the noise level at or below
about 77 decibels. Vibrations are suppressed by the frame and
housing, which are formed by frame members, segments and panels
having different sizes and shapes so that they do not vibrate at
the same natural frequency, and tend to cancel or attenuate
vibrations passing from one frame or panel member to another. Thin
acoustic insulation sheets combine with the housing panels to form
dead zones that absorb noise. The sheets and dead zones are
compactly arranged inside the frame segments so that the size and
footprint of the assembly is kept to a minimum. Two transparent
housing panels form dual opposed windows that provide the lighting
to and allow the viewing of the motorized pump assembly and other
internal components.
[0012] One advantage of the present motorized pump assembly is its
reduced noise level. Although the motorized high pressure pump
produces hydraulic pressures of about 2,000 to 10,000 psi or more
at flow rates of 4 to 18 gpm or more, the noise level of the
assembly at a distance of three feet from the unit is kept to about
75 to 77 decibels or less. This noise reduction is a result of
reduced vibration and the use and arrangement of noise absorbing
sheets placed in the windows of the frame segments. The thin,
plastic, sound absorbing sheets have a porous surface that dampens
noise. The sheets are sonically welded to the inside surface of the
plastic housing. The sheets are folded to form a box shape. The
sheets have a flat main portion that is spaced from the housing to
form a dead zone of air between the sheet and the housing. The
sheets and dead zones are compactly arranged to fit within the
windows of the frame segment. A bottom sheet is also located along
the bottom of the frame. The motor intake air vent and the exhaust
vent at the top of the frame include noise insulation and baffles.
The dramatic reduction in noise of the present motorized pump
assembly meets the noise level requirements for machinery and
equipment used in many industrial setting such as Ford Motor
Company manufacturing plants.
[0013] Another advantage of the present motorized pump assembly is
vibration suppression. High pressure pumps generate large pulses of
energy and vibrations. The drive motor also generates vibrations.
The structure of the frame inhibits the transmission and
multiplication or excitement of these vibrations. The frame is
composed of upper and lower portions. The upper portion is formed
by frame members with different cross sectional sizes than the
lower portion. The frame is also formed by several frame segments.
These segments have different shapes and sizes, and do not form a
square. The platforms on which the motor and pump are mounted are
also constructed differently and include plates having different
thicknesses. This construction produces frame segments and parts
with different natural frequencies that inhibit the multiplication
or excitement of vibrations. The construction also helps attenuate
and minimize the propagation of the motor and pump vibrations
through the frame. The shafts of the motor and pump are also offset
from the center of the housing, and flex hose and shock absorbing
rubber mounting pads are used to reduce vibration excitement and
propagation. This vibration suppression reduces the wear and tear
on the frame, housing and internal components attached to the
frame. The reduced vibration also reduces the noise level of the
overall assembly.
[0014] A still further advantage of the present motorized pump
assembly is the visibility and lighting of its active internal
components. Good visibility and lighting are particularly important
because external noise is below 77 decibels, while the background
noise of many manufacturing settings is typically about or above 80
decibels. As a result, workers cannot hear component noises inside
the acoustic frame and housing assembly that would otherwise signal
a need for maintenance or an impending malfunction, such as a high
pitched whir of a worn drive belt. Although the frame and housing
assembly surround the internal components, two panels are
transparent plastic to provide windows for viewing those
components. The windows are located on the front and rear of the
assembly. This opposed, dual window design allows light to enter
the opposite side from the line of sight of the viewer to provide
backlighting for each window. A worker can view the internal
components through either window without shadowing that can hide or
hinder the observation of smoke, leaks, belt deterioration or
loosening, excessive vibration, or other sometimes difficult to
detect abnormalities. The accumulation of belt flakes or leaking
fluid at the bottom of the housing is easily seen through the front
window, which spans from the bottom to the top of the assembly, and
which is located directly in front of and provides unobstructed
viewing of the pulley and drive belt assembly. The rear window is
located directly behind and allows for unobstructed viewing of the
pump and motor. The rear window is angled relative to the vertical
front window. This angled arrangement inhibits the reverberation of
noise between the windows, and provide a clear view of both the
pump and motor, which are stacked one on top the other. The dual
window design utilizes ambient room light and avoids the problems
of providing and maintaining a fixed internal light source, which
can also produce a shadowing effect. The ergonomic design also
allows workers to properly inspect the internal components without
bending over, kneeling down or contorting their body into an
unnatural position. As a result, the expensive, high speed
equipment can be routinely inspected to ensure their proper
operation.
[0015] A still further advantage of the present motorized pump
assembly is its ventilation. Both the pump and motor are adequately
ventilated and cooled by room air so that they do not overheat. The
high power electric motor and the pump are kept within design
specifications during operation. The air vent openings in the
housing include baffles to abate the transmission of noise, and are
located where they do not obstruct visibility through the front and
angled rear windows.
[0016] A still further advantage of the present motorized pump
assembly is its added safety. The rotating shafts, pulleys and
drive belt of the motorized pump assembly are enclosed in the frame
and housing of the assembly. The windows are thick panels of
transparent Lexan plastic. Workers do not have to open the housing
or physically handle the unit to view the motorized pump assembly
15. Checking for smoke, excessive shaking, fluid leaks, belt
flaking or loosening, bulging hoses, and other maintenance
inspection requirements can be easily observed. Workers remain
behind the housing and away from the spinning components.
[0017] A further advantage of the present motorized pump assembly
is its compact size, which is achieved by a number of design
features. First, the pump and motor have a stacked arrangement. The
pump is located above the motor. Second, only active high speed
components such as the pump, motor and pulley drive are enclosed in
housing of the assembly. Static components such as tanks and
control panels that do not require vibration and noise control are
positioned outside the frame and housing. Third, the noise
absorbing sheets are thin and effective. Bulky masses of insulation
are not used. Fourth the noise absorbing sheets are located inside
the openings or windows of the frame segments so that they do not
increase in the overall size of the assembly. The surface area of
the noise insulation actually exceeds the surface area of the
interior space of the assembly. Thus, the overall assembly has a
small footprint and conserves manufacturing floor space. The
compact size also reduces the cost of enclosing the motorized pump
in an acoustic housing.
[0018] A still further advantage of the present motorized pump
assembly is its ergonomic design and ease of maintenance. By
elevating the frame, workers can more easily perform routine
maintenance such as oil changes, applying lubricants, filter
cleaning or replacement, bolt tightening, hose replacement, etc. A
small access opening is provided in the rear window so that a
worker can check the oil level without removing any housing panels.
The opening is located directly above the oil dip stick and allows
the worker to see his or her hand and the dip stick as they reach
into the housing. Workers do not need to bend over or work off the
floor. The elevated design also allows dirt and debris to be easily
cleaned away from the floor and around the unit, even during
operation.
[0019] Other aspects and advantages of the invention will become
apparent upon making reference to the specification, claims and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of a conventional motorized
pump assembly for a high pressure, positive displacement pump that
provides discharge pressure of over 2,000 psi and has a noise level
of over about 90 decibels.
[0021] FIG. 2 is a side view of the conventional motorized pump
assembly of FIG. 1.
[0022] FIG. 3 is a rear view of the conventional motorized pump
assembly of FIG. 1.
[0023] FIG. 4 is a top view of the conventional motorized pump
assembly of FIG. 1.
[0024] FIG. 5 is a front perspective view of the present pump,
frame and housing assembly with the front transparent panel and
other exterior housing panels and insulation in place, and showing
a partial view of the electric motor, high pressure pump and drive
assembly.
[0025] FIG. 6 is a rear perspective view of the present pump, frame
and housing assembly with the rear transparent panel and other
exterior housing panels and insulation in place, and showing a
partial view of the electric motor and high pressure pump.
[0026] FIG. 7 is an exploded, rear perspective view of the present
pump, frame and housing assembly with the housing removed and to
reveal the noise absorbing sheets, support frame, and motorized
pump assembly.
[0027] FIG. 8 is a side view of the motorized pump assembly
invention of FIG. 7.
[0028] FIG. 9 is a rear view of the motorized pump assembly
invention of FIG. 7.
[0029] FIG. 10 is a top view of the motorized pump assembly
invention of FIG. 7.
[0030] FIG. 11 is an exploded perspective view of the frame of the
present motorized pump assembly showing individual noise
attenuation sheets.
[0031] FIG. 12 is an overhead view showing noise level readings in
decibels at various locations around the present motorized pump
assembly during operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] While this invention is susceptible of embodiment in many
different forms, the drawings show and the specification describes
in detail a preferred embodiment of the invention. It should be
understood that the drawings and specification are to be considered
an exemplification of the principles of the invention. They are not
intended to limit the broad aspects of the invention to the
embodiment illustrated.
[0033] The present invention pertains to a pump, frame and housing
assembly generally indicated by reference number 10 and shown in
FIGS. 5 and 6. The assembly 10 includes an internal motorized pump
assembly 15 and a frame, housing and acoustic insulation assembly
50. The motorized pump assembly 15 includes an electric motor 20, a
high pressure pump 30 and a drive assembly 40. The frame, housing
and insulation assembly 50 includes a frame 60, housing 150 and
acoustic insulation 200. The frame 50 supports the motorized pump
assembly 15 and forms an interior space 55 sized to compactly
contain these active components. The frame 60 also supports the
housing 150 and insulation 200, which surround and acoustically
insulate the active components and provide windows for viewing
them.
[0034] The electric motor 20 has a housing 22 and rotating drive
shaft 24. The motor 20 receives electric power via an electric cord
25 that is plugged into the main power supply system for the
manufacturing plant. The motor 20 has an internal cooling fan that
draws air through an intake tube 26 and into the housing 22 as
shown in FIG. 7. The intake tube 26 is made of loaded rubber for
acoustic purposes. A simple styrofoam baffle is also provided in
the intake tube 26 for acoustic purposes. Air flows around the
baffle and between the baffle and the vent tube. The electric motor
20 is preferably a three-phase, 25 horsepower (Hp) motor that
rotates at about 1,200 to 1,800 rotations per minute (rpms). The
motor 20 preferably has a foot mounted housing, weight of about 325
pounds, and length, width and height dimensions of about 500
millimeters (mm), 360 mm and 400 mm, respectively, such as the
Model M3AA made by ABB of Detroit Mich. The air intake vent 26 is
made of loaded rubber to help reduce noise transmission through its
several openings in the housing 150.
[0035] The high pressure pump 30 is preferably a positive
displacement pump designed to produce at least 2,000 pounds per
square inch (psi) of hydraulic pressure. The pump 30 has an
elongated housing 32 that extends horizontally as shown in FIGS. 7,
9 and 10. The pump housing 32 and its three internal pistons extend
generally perpendicular to the motor housing 22. The pump 30 has an
input or driven shaft 34 that is aligned generally parallel to the
drive shaft 22 of the electric motor 20. The pump 30 has a low
pressure inlet 35 and a high pressure outlet 36. The inlet 35 is
connected to the low pressure or return line of the manufacturing
system and carries fluid at a pressure of about 35 psi. The outlet
36 is connected to the high pressure line of the manufacturing
system. The inlet and outlet 35 and 36 of the pump 30 are
preferably connected to the piping of the manufacturing system via
flex hose to help reduced vibration and noise. The pump 30 includes
an oil level dip stick 37. In combination with the 25 Hp motor 20,
the high pressure pump 30 is capable of producing a discharge flow
rate of about 17 gallons per minute (gpm) at 2,000 psi, 9 gpm at
3,800 psi, 6 gpm at 6,000 psi, and 4 gpm at 9,000 psi. The high
pressure positive displacement pump 30 has a weight of about 270
pounds, and length, width and height dimensions of about 760 mm,
400 mm and 260 mm, respectively, and is preferably of the type
manufactured by Hammelmann Corp. of Dayton, Ohio as Model Number
HDP 22 or 32. The pump 30 has a stroke length of about 60 mm and an
average piston speed of 430, 510 or 610 rpms. Model Nos. HDP 20 and
40 are also believed possible for an alternate version of the
assembly 10.
[0036] The pulley drive assembly 40 connects the electric motor 20
to the high pressure pump 30 as best shown in FIGS. 5, 7 and 8.
This power transmission assembly 40 includes a drive pulley 42 that
is rigidly secured to the drive shaft 24 of the electric motor 20,
and a driven pulley 43 that is rigidly secured to the driven shaft
34 of the high pressure pump 30. A drive belt 45 is snuggly
positioned around the pulleys 42 and 43 so that power from the
motor shaft 24 is transmitted to the pump shaft 34. The drive
pulley 42 has a smaller diameter than the driven pulley 43 so that
the pump shaft 34 rotates at a slower speed than the motor shaft
24. The circumference of the driven pulley 43 is about 4.3 times
greater than the circumference of the drive pulley 42. As discussed
below, the height of the electric motor 20 is adjustable to
maintain the belt 45 in tight engagement with the pulleys 42 and
43. Although the pulley drive 40 is shown and described, those of
skill in the art should understand that other drive mechanisms
could be used without departing from the broad aspects of the
invention. Similarly, although an electric motor 20 and positive
displacement pump 30 have been shown and described, those of skill
in the art should understand that other types of motors and pumps
could be used without departing from the broad aspects of the
invention.
[0037] The frame, housing and insulation assembly 50 form an
enclosed volume or space 55 for housing the motorized pump assembly
15 as shown in FIGS. 5 and 6. The motor 20 and pump 30 are offset a
slight distance from the centerline 57 of the assembly 50 as best
shown in FIG. 9. This assembly 50 includes a frame 60, housing 150,
and a plurality of noise absorbing sheets 200. The frame 60 has a
front 61, rear 62, top 64, bottom 65, and sides 66 and 68 as shown
in FIGS. 7-10. The frame 60 is robustly designed to support the
motorized pump assembly 15, as well as the housing 150. The pulley
drive 40 is located adjacent the front 61 of the frame 60, and the
elongated pump 30 extends toward the left side 68 of the frame. The
frame 60 is formed by a plurality of frame segments 70. These
segments 70 include a front segment 71, lower and angled upper rear
segments 72 and 73, a top segment 74, a bottom segment 75, lower
and upper right side segments 76 and 77, lower and upper left side
segments 78 and 79, and an arcuate side frame segments 80. Other
than arcuate segment 80, each segment 70 has four sides. Each
segment 70 is welded or otherwise rigidly joined to its adjacent
segments to form an irregularly shaped box-like enclosure.
[0038] Each segment 70 has at least two sides of unequal length for
vibration suppression and noise reduction reasons. No segment 71-80
has a square or equilateral triangular configuration. The front,
rear, top, and bottom segments 71-75 each have a rectangular shape
that is different from any other segment 70. Although the lower
side segments 76 and 78 share a common rectangular shape, this
rectangular shape differs from the other segment 70. Similarly, the
upper side segments 77 and 79 have a trapezoidal shape that differs
from the other segments 70, and the arcuate side segment 80 have a
curved shape that differs from the other segment.
[0039] The segments 70 are formed by individual frame members 91
that are welded or otherwise integrally connected. Adjacent
segments 70 share a common frame member 91. Segments 71-79 are each
formed by four elongated, perimeterally aligned, frame members 91.
The front, side and rear segments 71-73 and 76-79 each include a
top, bottom and side members 91. Similarly, the top and bottom
segments 74 and 75 each include a front, rear and two side members
91. The bottom, lower rear and side segments 72, 75, 76 and 78 are
formed by the lower frame members 92. The lower members 92 have a
tubular construction with a cross-sectional shape of 11/2 inches by
3 inches. The top, upper rear and side segments 73, 74, 77 and 79
are formed by upper frame members 94. The upper members 94 have a
tubular construction with a cross-sectional shape of 11/2 inches by
11/2 inches. Because the front frame segment 71 spans from the top
64 to the bottom 65 of the frame 60, it includes both upper and
lower frame members 92 and 94. The arcuate segment 80 is formed by
two arcuate frame members 96 to help enclose the outer end of the
high pressure pump 30. Arcuate segments 96 are spaced apart and in
aligned registry with each other, and extend from the left side 68
of the fame 60. Except for the bottom segment 75, each segment 70
is free of any cross bracing between its respective members 91. As
a result, the entire inner side wall 98 of each of these segments
70 forms an opening or window 100 that is free of any
obstructions.
[0040] The lower segments 73, 75, 76 and 78 and their respective
lower frame members 92 form a lower portion 110 of the frame 60.
This lower portion 110 defines a lower interior space 112 of the
entire enclosed area 55. The upper frame segments 72, 74, 77 and 79
and their respective upper frame members 94 combine to form an
upper portion 115 of the frame 60. This upper portion 115 defines
an upper interior space 117 of the entire interior 55. The frame 50
is elevated from a supporting surface by a set of four legs 119.
Each leg 119 extends downwardly from one of the four corners of the
bottom frame segment 75. Each leg includes an adjustment shoe for
leveling the frame. The bottom segment 75 includes a set of two
forklift tubes 142 for picking up and moving the assembly 10.
[0041] A lower platform 120 supports the electric motor 20. This
platform 120 includes a set of cross beams or tubes 122 that are
welded to and extend between the side frame members 92 of the
bottom frame segment 75. A lower mounting plate 123 is welded or
otherwise rigidly secured to these cross beams 122. A set of four
adjustable mounting legs 124 support a generally horizontal, upper
mounting plate 125. The mounting plate 125 has a thickness of about
1/2 inch. The motor 20 is bolted to this plate 125. The adjustable
legs 124 are used to maintain the desired tension of the belt 45,
and keep the belt in secure friction bearing engagement with
pulleys 42 and 43.
[0042] An upper platform 130 supports the high pressure pump 30.
The upper platform includes a set of cross beams or tubes 132
extending between the upper side frame members 92 of the lower side
frame segments 76 and 78. Tubular mounting posts 134 are welded to
these cross beams 132 to elevate an upper plate 135. The mounting
plate 135 has a thickness of about one inch. The pump 30 is bolted
to this plate 135. The size, shape and thickness of the mounting
plates 125 and 135 are different to help suppress vibration and
minimize noise. The mounting posts 134 elevate the pump 30 to a
location that is cantered from but more near the center of the
upper interior space 117 of the frame 50. Both the motor 20 and the
pump 30 are slightly cantered from the center of the interior area
55 towards the right side 66 of the frame 50 to further assist in
suppressing vibration and attenuating noise.
[0043] The housing 150 surrounds and encloses the motorized pump
assembly 15 interior space 55 and frame 60. The housing 150 is
formed by a front panel 151, upper angled and lower rear panels 152
and 153, top panel 154, side panels 156-159, and arcuate panels 160
and its side panels 161. The panels 150 are robustly designed to
protect the motorized pump assembly 15 from being inadvertently
struck by an external object, and protect workers from any parts
such as the drive belt 145 that may become detached during
operation. The housing 150 has a height of about 41/3 feet without
its legs 119 and just 51/3 feet with its legs. The housing has a
width of 21/2 feet without the arcuate portion, a width of about
31/2 feet with the arcuate portion, and depth of about 31/2
feet.
[0044] The front panel 151 and upper angled rear panel 152 are
transparent. Each of these panels 151 and 152 is intended to form a
window allowing ambient room light to enter its internal space 55
and for viewing the motorized pump assembly 15 and interior space.
These dual opposed windows 151 and 152 are preferably made of Lexan
plastic and have a thickness of about 1/4 inches. The front panel
or window 151 provides an unobstructed view of the drive assembly
40, as well as a view of the motor 20 and pump 30 themselves
located behind the drive assembly. The rear angled panel or window
152 provides an unobstructed view of both the motor 20 and pump 30.
The rear angled window 152 includes an access cap 175 sized to
allow a worker to insert his or her hand to remove and check the
oil level dip stick 37 of the pump 30. Any undesired smoke,
excessive shaking of the motor 20 or pump 30, loosening or flaking
of the drive belt 45, leaking of pressurized fluid, or other
observable signs indicating a need for maintenance, can easily be
seen through these windows.
[0045] The remaining panels 153-161 are opaque, and are not
intended to help acoustically insulate the assembly 10. The lower
rear 153, top 154, side 156-159, and arcuate 160 and 161 panels are
made of high density polyethylene (HDPE) plastic or marine plastic
of the type used in the boat industry. Each panel 153-161 is
approximately 1/2 inches thick. The bottom panel 155 is a metal
plate 155. The perimeter of each panel 151-161 is bolted or
otherwise securely fastened to its respective frame segment or
segments 70. The panels 151-161 substantially completely enclose
the interior area 55 of the assembly 10. The vents 153a and 154a
and bottom plate 155 allow some open, baffled or acoustically
insulated pathways between the interior 55 and the exterior of the
assembly 10. Baffle 28 is placed over vent 153a, spaced from and
attached to the housing panel 153. The outlet vent 154a in top
panel 154 allows air to flow past the pump 30 and out of the
interior area 55 so that the heat generated by the motor 20 and
pump 30 is expelled. Each of the panels 151-161 is shaped so that
its outer perimeter flushly engages the outer edge of its
respective frame segment 70. Each panel 151-161 has an inside
surface facing the interior area 55. Although the perimeter of each
panel 151-161 abuts its frame segment 70, a main inner portion of
the inside surface 171 of each panel remains free of obstructions,
except for side panel 158 which has an opening cut into it for
receiving the outer end of the pump 30.
[0046] Acoustic or noise-absorbing sheets 200 are placed in the
windows 100 of the frame segments 70 covered by opaque housing
panels 153-160. These sheets 200 are high density polyethylene
(HDPE) plastic that are machined to have a roughened and
micro-perforated surface 201. Although the pores go completely
through the sheet 200, from one side of the sheet to the other,
they are very small and do not readily permit air flow through the
sheet. The acoustic sheets 200 have a thickness of about 0.04
inches, a density of about 0.95 grams per cubic centimeter (g/cc)
and are preferably of the type manufactured by American Acoustical
Products of Holiston, Mass. under the brand name Millennium
Material (MM).
[0047] The acoustical sheets 200 are self-supporting and are
preferably formed into a box-like structure 204 for additional
rigidity. The box structure 204 has a flat inwardly facing main
portion 205, two opposed spacing legs or flanges 206, and a flat
rearwardly facing portion 207. The rear portion 207 is sonically
welded to the inside surface 171 of its respective housing panel
153-160. The main inwardly facing portion 205 is spaced from its
rear portion 207 and the surface 171 of its respective panel
153-160 a distance of about 1 to 4 inches and preferably about 2
inches. The panels 153-160 can include spacing bars projecting from
their surface of 171 to help maintain the spacing of the main
portion 205 of each sheet 200 and its box-like structure 204. Each
acoustic sheet 200 or box shaped structure 204 is shaped to flushly
fit between the side walls 98 of its respective frame window 100.
The box shaped 204 acoustic sheet 200 inserted into the window 100
of the top segment 74 has slits 209 that form a baffle and
cooperate with the vent 154a in the upper panel 154. The frame and
housing assembly 50 preferably includes eight acoustic sheets
213-220, one for each acoustically insulated segment 73-80.
[0048] Noise absorbing pockets or dead zones 240 are created by
spacing the main portions 205 of the acoustic sheets 200 from its
rear portion 207 or the surface 171 of its respective housing panel
153-160. These dead zones 240 combine with the acoustic properties
of the sheets 200 to reduce or attenuate any noise trying to pass
through the frame, housing and insulation assembly 50. The dead
zones 240, and the acoustic sheets 200 and their U-shaped or
box-like structures 204 are located between the sidewalls 98 of the
frame members 91 forming the windows 100 of the frame segments
70.
[0049] The following formula is widely accepted to calculate noise
reduction:
IL=TLc+10 log(({grave over (.alpha.)}Sa+0.05(St-Sa))/St)
[0050] Where: [0051] IL=maximum achievable reduction in dB [0052]
TLc=composite transmission loss [0053] {grave over
(.alpha.)}=sabine absolution coefficient [0054] Sa=total area of
sound absorption [0055] St=total surface area of enclosure
[0056] In the present design, the total surface area of the
interior space 55 and the surface area of the noise absorbing
materials such as loaded rubber vent 26 and sheets 200 are as
follows:
TABLE-US-00001 Exterior Area Acoustic Area Front window 71 10.59
Front 0.0 Angled window 72 7.29 Angled 0.0 Back segment 73 5.38
Back 213 8.2 Top segment 74 2.69 Top 214 4.4 Bottom segment 75 7.68
Bottom or base 215 10.4 Side segments 76, 77 11.95 Upper left side
217 6.9 Side segments 78, 79 11.95 Lower left side 216 8.1 St =
57.53 Upper right side 219 6.9 Lower right side 218 8.1 Internal to
cap 214 11.4 Sa = 64.4
[0057] For a motorized pump assembly 15 having an output of 90
decibels and the following composite transmission loss (TLc) and
sabine absolution coefficient ({grave over (.alpha.)}), we obtain
the following theoretical achievable reduction (IL) and projected
decibel levels. These projected decibel levels coincide with the
actual decibel levels obtained for the pump, frame and housing
assembly 10 as shown in FIG. 12.
TABLE-US-00002 Frequency (Hz) TLc A IL Decibel level 100 7.4 0.5
13.1 76.9 500 10.9 0.6 17.7 72.3 1,000 16.7 0.85 27.1 62.9 10,000
11.3 0.7 20.7 69.3
[0058] The acoustic frame, housing and insulation assembly 50
preferably does not contain opposed parallel surfaces that are not
acoustically insulated and would reflect noise back and forth in an
excited reverberating manner. Although transparent panels 151 and
152 are not acoustically insulated, they are also not parallel so
that sound waves do not reverberate back and forth between them. At
least one of each pair of opposed parallel panels 151 and 153, 154
and 155, 156 and 158, and 157 and 159 has acoustic insulation to
reduce noise. The side panels 161 of the arcuate portion 160 are
also preferably not parallel.
[0059] Acoustic measurements taken for the motorized pump assembly
15 mounted on a frame without the housing 150 and acoustic
insulation 200 produce noise levels of about 90 decibels or more at
a distance of three feet from the equipment 15. With the motorized
pump assembly 15 mounted to the frame and housing assembly 50 with
housing 150 and acoustic insulation in place, the assembly 10
produces acoustic measurements of about 75 to 77 decibels taken at
locations of about three feet from the equipment 15 as shown in
FIG. 12.
[0060] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted without departing from the broader aspects of the
invention.
* * * * *