U.S. patent application number 10/774637 was filed with the patent office on 2005-08-25 for cooling fan mechanism for a motor-driven pressure washer.
Invention is credited to Bjarnason, Rory, Zarbi, Ghassem.
Application Number | 20050186091 10/774637 |
Document ID | / |
Family ID | 34860819 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050186091 |
Kind Code |
A1 |
Zarbi, Ghassem ; et
al. |
August 25, 2005 |
Cooling fan mechanism for a motor-driven pressure washer
Abstract
An improved cooling fan mechanism for an motor-driven pressure
washer which includes a generally toroidal drive pulley rotatably
mounted within the pressure washer which is driven by an engine,
the drive pulley including a generally cylindrical outer rim, a
central hub and a plurality of spokes extending between the central
hub and the outer rim for supporting the outer rim with at least
some of the plurality of spokes of the drive pulley each consisting
of an angled, generally planar fan blade having a forward
air-engaging edge generally adjacent the outer side of the outer
rim and a rearward edge generally adjacent the inner side of the
outer rim, the forward air-engaging edges of the fan blades
operative to engage air upon rotation of the drive pulley and force
air into the pressure washer via the fan blades to cool the
interior of the pressure washer.
Inventors: |
Zarbi, Ghassem; (Abbotsford,
CA) ; Bjarnason, Rory; (Abbotsford, CA) |
Correspondence
Address: |
Adam H. Jacobs
Suite 726
1904 Farnam Street
Omaha
NE
68102
US
|
Family ID: |
34860819 |
Appl. No.: |
10/774637 |
Filed: |
February 9, 2004 |
Current U.S.
Class: |
417/362 |
Current CPC
Class: |
F04B 17/05 20130101;
F04B 53/08 20130101 |
Class at
Publication: |
417/362 |
International
Class: |
F04B 017/00 |
Claims
We claim:
1. An improved cooling fan mechanism for a motor-driven pressure
washer comprising; a generally toroidal drive pulley rotatably
mounted within the pressure washer, said drive pulley driven by a
motor within the pressure washer; said drive pulley including a
generally cylindrical outer rim having inner and outer sides, a
central hub having a central rotational axis and a plurality of
spokes extending between said central hub and said outer rim for
supporting said outer rim in spaced relation from said central hub;
at least some of said plurality of spokes of said drive pulley each
consisting of an angled fan blade having a forward air-engaging
edge generally adjacent said outer side of said outer rim and a
rearward edge generally adjacent said inner side of said outer rim;
said forward air-engaging edges of said fan blades operative to
engage air upon rotation of said drive pulley and said angled fan
blades operative to force the engaged air into the pressure washer
via said fan blades to cool the interior of the pressure washer
thereby reducing the internal temperature of the pressure
washer.
2. The cooling fan mechanism for motor-driven pressure washers of
claim 1 wherein said fan blades are angled between approximately
ten to forty-five degrees (10.degree. to 45.degree.) from
perpendicular to the central rotational axis of said center hub of
said drive pulley thereby deflecting air encountered during the
rotation of said drive pulley towards said inner side of said drive
pulley and inwards to internal elements of a motor-driven pressure
washer.
3. The cooling fan mechanism for motor-driven pressure washers of
claim 1 wherein each of said spokes of said drive pulley consist of
one of said angled fan blades.
4. The cooling fan mechanism for motor-driven pressure washers of
claim 1 wherein said angled fan blades each further comprise an air
deflection plate having a slight concave curvature for enhancing
air propulsion towards internal elements of a motor-driven pressure
washer.
5. In combination: an motor-driven pressure washer including a base
platform, a motor mounted on said base platform including a
rotating power output shaft, a generally toroidal drive pulley
mounted on said rotating power output shaft for rotating said drive
pulley, water pump means mounted on said base platform, a drive
belt extending between said drive pulley and said water pump means
for operating said water pump means and a safety housing having at
least one wall structure at least partially enclosing said drive
pulley, said water pump means and said drive belt; and an improved
cooling fan mechanism for said motor-driven pressure washer
including; said drive pulley including a generally cylindrical
outer rim having inner and outer sides, a central hub having a
central rotational axis and a plurality of spokes extending between
said central hub and said outer rim for supporting said outer rim
in spaced relation from said central hub; at least some of said
plurality of spokes of said drive pulley each consisting of an
angled fan blade having a forward air-engaging edge generally
adjacent said outer side of said outer rim and a rearward edge
generally adjacent said inner side of said outer rim; said forward
air-engaging edges of said fan blades operative to engage cooling
air upon rotation of said drive pulley by said motor and pull
cooling air into said safety housing of said motor-driven pressure
washer via said fan blades to circulate cooling air through the
interior of said motor-driven pressure washer thereby reducing the
internal temperature of said motor-driven pressure washer.
6. The combination of claim 5 wherein said safety housing further
comprises at least one air passage opening generally adjacent said
outer side of said drive pulley to permit air flow into said safety
housing for cooling of the internal temperature of said
motor-driven pressure washer.
7. The combination of claim 6 wherein said safety housing further
comprises at least one air passage opening generally adjacent said
inner side of said drive pulley to permit air flow out of said
safety housing towards said motor for cooling of temperature of
said motor.
8. The combination of claim 5 wherein said fan blades are angled
between approximately ten to forty-five degrees (10.degree. to
45.degree.) from perpendicular to the central rotational axis of
said center hub of said drive pulley thereby deflecting air
encountered during the rotation of said drive pulley towards said
inner side of said drive pulley and inwards to internal elements of
said motor-driven pressure washer.
9. The combination of claim 5 wherein each of said spokes of said
drive pulley consist of one of said angled fan blades.
10. The combination of claim 5 wherein said angled fan blades each
further comprise an air deflection plate having a slight concave
curvature for enhancing air propulsion towards the internal
elements of said motor-driven pressure washer.
11. The combination of claim 5 wherein said central hub of said
drive pulley further comprises a center air-seal disk which is
operative to generally prevent negative airflow into the center of
said central hub of said drive pulley.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention is directed to pressure washers and,
more particularly, to an improved cooling fan mechanism for a
motor-driven pressure washer which includes a generally toroidal
drive pulley rotatably mounted within the pressure washer which is
driven by an engine within the pressure washer, the drive pulley
including a generally cylindrical outer rim having outer and inner
sides, a central hub and a plurality of spokes extending between
the central hub and the outer rim for supporting the outer rim in
spaced relation from the central hub with at least some of the
plurality of spokes of the drive pulley each consisting of an
angled, generally planar fan blade having a forward air-engaging
edge generally adjacent the outer side of the outer rim and a
rearward edge generally adjacent the inner side of the outer rim,
the forward air-engaging edges of the fan blades operative to
engage air upon rotation of the drive pulley and force air into the
pressure washer via the fan blades to cool the interior of the
pressure washer thereby reducing the internal temperature of the
elements of the pressure washer.
[0003] 2. Description of the Prior Art
[0004] Pressure washers are incredibly versatile and effective
cleaning tools. They can be used for vehicle cleaning, removing
stains, moss and mildew from brickwork, driveways, paths, patios
and even garden furniture. With the right attachment they can even
be used for cleaning and unblocking drains.
[0005] Pressure washers generate a high-speed, focused jet of water
by using a powerful motor to pump water (usually fed from a garden
hose) to very high pressures. This produces a high speed, highly
penetrating jet of water that is directed by a long handled lance
at the object to be cleaned. Pressure washers are also extremely
efficient and use as little as {fraction (1/10)} the volume of
water used by an ordinary garden hose.
[0006] Pressure washers fall into two main categories:
[0007] i. Cold water pressure washers take water fed directly from
the cold water main supply and pump it out at high pressures
(70-270 bar or 1000 to 4000 psi). On better quality machines, a
siphon tube or reservoir permits the addition of special detergents
to aid cleaning. There is a mechanism attached to this siphon tube
that prevents back flow and city water contamination. Cold water
pressure washers are excellent at removing organic matter, mud,
dirt and all water-soluble compounds. They will also remove fats,
oils and greases but work much better if degreasing compounds are
worked into these non-soluble compounds first.
[0008] ii. Hot water pressure washers work in the same way as their
cold water counterparts but heat the water up (before pumping) to
100.degree. C.-140.degree. C. in an internal boiler. Hot water
pressure washers can be modified to be used as steam cleaners.
Steam cleaners require an electricity supply and a liquid fuel such
as heating oil or paraffin to heat the boiler.
[0009] Hot water pressure washers are excellent at removing very
heavy deposits of oils and greases from the objects being cleaned
and tend to leave a drier surface afterwards. Hot water pressure
washers are also especially useful for stripping off old, hardened
underseal. Because they can strip away non-soluble compounds
without the need for a degreasing solution, they should only be
used where the waste run-off passes through a special oil/water
separator. Hot water pressure washers are considerably more
expensive than cold-water cleaners.
[0010] The two conventional predominant pressure washer systems in
use today are belt-drive and electric pressure washers. They rely
on an engine to run the system and a water pump to pump the water
at very high pressures. The direct-drive is for applications not
requiring more than 30 hours of use per week. The pump is directly
coupled to the engine or motor causing the pump to spin twice as
fast as the belt drive models.
[0011] The belt-drive is most commonly found on industrial models
and is ideal for cleaning applications requiring 40+ hours of use
per week. The belt connecting the engine to the high-pressure pump
generates heat due to the high friction between the pulleys and
belt. The generated temperature rises to a temperature close to, or
even sometimes higher than the limit of the belt and causes the
thermal expansion of the belt material thus promoting the
development of belt shredding and slip problems. The heat is also
transferred to pump and other key components through conduction,
which results in an additional rise in their operational
temperature. There is therefore a need for an improved cooling fan
mechanism which will decrease the operational temperature of the
components of the pressure washer thereby enhancing the cycling
life of belts, pump and other key components of the belt-drive
unit.
[0012] Without sufficient system airflow, many of today's pressure
washer systems would overheat. Air can flow passively through
system (this is the least expensive and most reliable form of
cooling) or it can be driven through the system by a fan or blower.
When a fan is required, system requirements will drive the
selection of the right fan for the application, such as system
pressure drop, acoustic restrictions, reliability requirements, and
product mobility. Each of these may play a role in the choice of
the fan system.
[0013] Fans can be thought of as low-pressure air pumps that
utilize power from a motor to output a volumetric flow of air at a
given pressure. A propeller converts torque from the motor to
increase static pressure across the fan rotor and to increase the
kinetic energy of the air particles. Each fan has only one design
point, which is established by a specific airflow, total pressure,
air density, and fan speed. Starting with these data, it is
possible to determine one platform and the twist distribution,
which will accomplish the required work with minimum
horsepower.
[0014] To move air, the fan must overcome two resistances, which
are measured as pressure drops across the fan. The first is a
parasitic loss called the velocity pressure loss, which is the
energy required to move the required air quantity without doing any
work to overcome the system resistance. However, work is being done
to move the hot air away from the equipment. The second resistance
is the static pressure loss, which is the accumulated loss due to
inlet louver, fill, drift eliminator, and fan inlet pressure drop,
etc. This represents the work to be accomplished and reflects the
design of the total system. Whether the air is distributed evenly
across the fan is primarily a function of the blade and hub design.
A properly designed blade will have adequate chord width and twist
to ensure an even distribution of velocity pressure over its entire
length. A properly designed hub will include a center air-seal
disk, which prevents negative airflow into the center of the
fan.
[0015] The selection procedure for the fan requires an optimum fan
diameter, number and type of blades, required pitch angle, fan rpm,
and some estimate of horsepower. In some cases, an estimated
sound-pressure level is essential to satisfy Environmental
Protection Agency (EPA) requirements for working area noise levels,
more importantly noise level at a plant boundary, or a given noise
sensitive location such as a residential area.
[0016] The factors that must be known when installing or replacing
a fan on an existing installation are:
[0017] Fan diameter.
[0018] Installed engine horsepower.
[0019] Gear reduction ratio of gear reducer.
[0020] Shaft size or gear reducer model.
[0021] Some estimate of elevation above sea level of
installation.
[0022] However, it is not always expedient to undertake such a
detailed review of the replacement or installation needs for a
cooling fan for the pressure washer, particularly in light of the
relatively inexpensive nature of many pressure washers. It is far
more preferable, then, that the pressure washer include an integral
cooling fan mechanism, one which does not require the user of the
pressure washer to perform significant additional functional
determinations to allow proper operation of the cooling fan
mechanism.
[0023] Therefore, an object of the present invention is to provide
an improved cooling fan mechanism for motor-driven pressure
washers.
[0024] Another object of the present invention is to provide an
improved cooling fan mechanism for motor-driven pressure washers
which includes a drive pulley mounted on the engine which includes
at least one generally planar fan blade replacing at least one of
the spokes of the drive pulley for directing air into the interior
of the pressure washer as the drive pulley is rotated.
[0025] Another object of the present invention is to provide an
improved cooling fan mechanism for motor-driven pressure washers
which includes a generally toroidal drive pulley rotatably mounted
within the pressure washer which is driven by an engine within the
pressure washer, the drive pulley including a generally cylindrical
outer rim having outer and inner sides, a central hub and a
plurality of spokes extending between the central hub and the outer
rim for supporting the outer rim in spaced relation from the
central hub with at least some of the plurality of spokes of the
drive pulley each consisting of an angled, generally planar fan
blade having a forward air-engaging edge generally adjacent the
outer side of the outer rim and a rearward edge generally adjacent
the inner side of the outer rim, the forward air-engaging edges of
the fan blades operative to engage air upon rotation of the drive
pulley and force air into the pressure washer via the fan blades to
cool the interior of the pressure washer thereby reducing the
internal temperature of the elements of the pressure washer.
[0026] Another object of the present invention is to provide an
improved cooling fan mechanism for motor-driven pressure washers
which generally eliminates the need for additional cooling fan
units to be used with the pressure washer.
[0027] Another object of the present invention is to provide an
improved cooling fan mechanism for motor-driven pressure washers
which provides a cooling air flow for the majority of the
operational elements of the pressure washer and will provide
additional volume of air movement as the rotational speed of the
engine is increased.
[0028] Another object of the present invention is to provide an
improved cooling fan mechanism for motor-driven pressure washers
which is usable with many different types of pressure washers, and
is not proprietary to any one specific unit.
[0029] Finally, an object of the present invention is to provide an
improved cooling fan mechanism for motor-driven pressure washers
which is relatively simple and durable in construction and is safe
and efficient in use.
SUMMARY OF THE INVENTION
[0030] The present invention provides an improved cooling fan
mechanism for a motor-driven pressure washer which includes a
generally toroidal drive pulley rotatably mounted within the
pressure washer which is driven by an engine within the pressure
washer, the drive pulley including a generally cylindrical outer
rim having outer and inner sides, a central hub and a plurality of
spokes extending between the central hub and the outer rim for
supporting the outer rim in spaced relation from the central hub
with at least some of the plurality of spokes of the drive pulley
each consisting of an angled, generally planar fan blade having a
forward air-engaging edge generally adjacent the outer side of the
outer rim and a rearward edge generally adjacent the inner side of
the outer rim, the forward air-engaging edges of the fan blades
operative to engage air upon rotation of the drive pulley and force
air into the pressure washer via the fan blades to cool the
interior of the pressure washer thereby reducing the internal
temperature of the elements of the pressure washer.
[0031] Prior to undertaking the preliminary and conceptual design
of the present invention, a market survey was conducted through
Internet searching, patent and literature searching, and by
contacting various manufacturers. The combination of fan-pulley and
belt-drive system in a pressure washer unit has not been attempted
in the past as the market survey showed. There is a particular
potential demand for the design that could offer temperature
reduction and lifetime extension in each component. With existing
conventional belt-drive pressure washer systems, the temperature of
each component increases as the device operates, and this component
heating reduces the lifetime and efficiency of the device.
[0032] The cooling fan mechanism for motor-driven pressure washers
as thus described provides several advantages not found in the
prior art. For example, because it is the drive pulley which
incorporates the fan elements of the present invention, additional
drive mechanisms for a separate fan blade unit are rendered
unnecessary. Also, the positioning of the fan blades within the
drive pulley permits the airflow directed by the rotation of the
fan blades to immediately access and cool the internal functional
elements of the pressure washer, and an external fan unit would not
be able to access the same area for cooling without interfering
with the safety and operation of the pressure washer operational
elements. Furthermore, the elimination of external fan units will
greatly reduce the risk of injury from contact with the rotating
fan blades, as the fan blades of the drive pulley are protected
within the housing. Finally, because the cooling fan mechanism for
motor-driven pressure washers of the present invention is capable
of being retrofitted onto existing pressure washer units, the
unique benefits of the invention can be added to many already
manufactured units. It is thus seen that the cooling fan mechanism
for motor-driven pressure washers of the present invention provides
a substantial improvement over those devices found in the prior
art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a perspective view of the motor-driven pressure
washer with the improved cooling fan mechanism of the present
invention fitted thereon;
[0034] FIG. 2 is a front elevational view of the cooling fan
mechanism of the present invention showing the modified drive
pulley;
[0035] FIG. 3 is a perspective view of the modified drive pulley of
the present invention;
[0036] FIG. 4 is a detailed exploded perspective view of the
motor-driven pressure washer of the present invention showing the
various elements thereof;
[0037] FIG. 5 is a rear side elevational view of the internal
features of the motor-driven pressure washer; and
[0038] FIG. 6 is an end elevational detailed view of the
motor-driven pressure washer and cooling fan mechanism of the
present invention showing air being drawn into the unit and
distributed to the internal operating elements of the motor-driven
pressure washer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] The improved cooling fan mechanism 10 of the present
invention is best shown in FIGS. 1-4 as being mounted on a
motor-driven pressure washer 80 for improved cooling of the engine,
pump and belts of the motor-driven pressure washer 80. Before
beginning the discussion of the improved cooling fan mechanism 10,
a brief description of the general features of the motor-driven
pressure washer 80 is needed in order to understand the functional
characteristics of the improved cooling fan mechanism 10. As shown
best in FIGS. 1 and 4, the motor-driven pressure washer 80 would
include a base platform 82 having wheels 84a and 84b and a forward
ground-engaging stand 86 mounted on the underside of the base
platform 82. A handle 88 would project upwards from the base
platform 82 for moving the motor-driven pressure washer 80. A
gasoline or electric-powered engine 90 is mounted on the base
platform 82, the engine 90 including a power output shaft 92 which
is rotated by the engine 90. Also mounted on base platform 82
rearwards of engine 90 is a water pump 94 which is connected to the
power output shaft 92 of engine 90 via a drive belt 96 or the like.
If the output speed of the power output shaft 92 of engine 90 is
generally constant, the relative speed of rotation of water pump 94
is controlled by the relative size of drive pulley 12 mounted on
power output shaft 92 of engine 90 and water pump drive pulley 98
mounted on the drive shaft 95 of water pump 94. Finally, the entire
drive belt mechanism is enclosed within a safety housing 100, as
shown best in FIGS. 1 and 4.
[0040] To this point, the motor-driven pressure washer 80 of the
present invention is of a generally standard type, and would
further include a hookup hose (not shown) to connect the water pump
94 to a water source, a high-pressure hose 102 connected to the
outflow of the water pump 94 and a trigger-controlled gun with a
flow-through wand handle 104 connected to the high-pressure hose
102 which is used in the standard pressure washer manner. However,
the present invention provides a significant improvement over those
pressure washer devices found in the prior art, in that the motor
drive pulley 12 includes modifications which enable the motor drive
pulley 12 to not only drive the water pump 94, but also provide
cooling for the motor-driven pressure washer 80 of the present
invention.
[0041] Specifically, the motor drive pulley 12 would include a
plurality of fan blades 14 which replace the standard spokes
extending between the center axle hub 16 and generally cylindrical
outer rim 18 of the motor drive pulley 12. In the preferred
embodiment, the motor drive pulley 12 would have a diameter of
approximately six to twelve inches (6" to 12") and would be
constructed of a rigid material such as cast iron, aluminum or
other such high-strength metal. As each of these fan blades 14 are
preferably constructed in a similar manner, the following
description of one of the fan blades 14 should be understood to
apply equally to each of the fan blades 14. Fan blade 14 is
preferably constructed as including a generally flat air deflection
plate 18, having a forward air-engaging edge 30 generally adjacent
outer edge 20 of outer rim 18 and a rearward edge 32 generally
adjacent inner edge 22 of outer rim 18, as shown best in FIG. 3. It
is further preferred that the air deflection plate 28 be angled at
an angle of approximately ten to forty-five degrees (10.degree. to
45.degree.) from perpendicular to the center axis of the motor
drive pulley 12 as per a standard fan blade to deflect air
encountered during the rotation of the fan blade 14 towards the
inner edge 22 of outer rim 18 and inwards to the internal elements
of the motor-driven pressure washer 80, including the engine 90 and
water pump 94. Also, it should be noted that the precise size and
shape of the air deflection plate 28 is not critical to the present
invention so long as the air encountering the air deflection plate
28 is deflected inwards towards and past inner edge 22 of outer rim
18 as described above. In fact, it is expected that slight concave
curvature of the air deflection plate 28 of fan blade 14 may be
desirable in order to provide additional air propulsion towards the
internal elements of the motor-driven pressure washer 80. Also, the
number of fan blades 14 is not critical to the present invention so
long as at least one of the spokes 13 of motor drive pulley 12 are
constructed as fan blades 14 to deflect and drive air for cooling
purposes into the interior of the motor-driven pressure washer
80.
[0042] Another important feature of the present invention is the
inclusion of louvers 50 positioned in the sidewall of drive belt
housing 100 adjacent the outer edge 20 of outer rim 18, as shown
best in FIGS. 1 and 4. These louvers 50 permit the entry of cooling
air into the drive belt housing 100 as drawn in by the rotating
action of the fan blades 14 on motor drive pulley 12. The cooling
air thus brought in through louvers 50 acts to cool the drive belt
96 and thus increase the lifespan of the drive belt 96.
[0043] Positioned on the opposite side of drive belt housing 100 is
a metal mesh screen 52 positioned adjacent the inner edge 22 of
outer rim 18 of motor drive pulley 12. The metal mesh screen 52
serves two purposes, the first being to permit transfer of cooling
air driven by rotational action of the fan blades 14 on motor drive
pulley 12 from the drive belt housing 100 into the vicinity of the
engine 90 for cooling thereof, and the second purpose being to
screen and prevent potentially harmful solid debris from being
directed into the engine 90 via the action of fan blades 14 of
motor drive pulley 12. Of course, it should be noted that various
other types of air passage structures may be used with the drive
belt housing 100 of the present invention which permit the passage
of cooling air to the engine 90 and drive belt 96, but it has been
found that the drive belt housing 100 which includes the louvers 50
and metal mesh screen 52 provides a safe, yet efficient,
arrangement of elements which permit the passage of cooling air to
the critical elements of the motor-driven pressure washer 80.
[0044] It is to be understood that numerous additions,
modifications, and substitutions may be made to the improved
cooling fan mechanism 10 of the present invention which fall within
the intended broad scope of the appended claims. For example, the
size, shape, and construction materials used in connection with the
improved cooling fan mechanism 10 and motor-driven pressure washer
80 of the present invention may be modified or changed so long as
the intended functional features of the invention are maintained.
Furthermore, the precise size, shape, number and angle of the fan
blades 14 on motor drive pulley 12 may be modified or changed
depending on the cooling characteristics desired and speeds at
which the motor drive pulley 12 will be rotated, and such
modifications to those fan blades specifics may be determined via
experimentation and operation. Also, as was stated previously, the
precise size, shape, and design of the drive belt housing 100,
louvers 50, and metal mesh screen 52, may be modified or changed so
long as the intended functional characteristic of permitting
passage of cooling air from the outside of the drive belt housing
100 there through and into the engine 90 is maintained or enhanced.
The present invention may also include a plurality of rubberized
vibration dampers 101 mounted on the drive belt housing 100 should
the use of such vibration dampers be desired. Finally, the layout
of the features of the motor-driven pressure washer 80 may be
modified or changed according to various manufacturers' designs,
but it should be noted that the motor drive pulley 12 having at
least one fan blade 14 thereon is a critical element of the
improved cooling fan mechanism 10 of the present invention and may
be adapted or modified for use with many different types of
motor-driven pressure washers.
[0045] There has therefore been shown and described an improved
cooling fan mechanism for a motor-driven pressure washer which
accomplishes at least all of its intended objectives.
* * * * *