CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims the benefit of Korean Patent Application No.
10-2012-0006244, filed on January 19, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated
herein in its entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a simple fire truck with easy movement, and more
particularly, to a simple fire truck that easily moves to a narrow fire occurred spot
difficult for a car to enter by using a transfer wheel driven by a motor separately
from a pump driven by an engine, prevents a damage of a sealing unit by depressurizing
a pressure transferred to the sealing unit by forming a groove between a chamber and
a suction unit formed inside a pump, and improves durability of a positive-displacement
pump through lubrication and cooling by using a lubricating water suction unit provided
at a pump suction unit during an initial activation.
2. Description of the Related Art
[0003] Generally, when a fire occurs, damage can be remarkably reduced if the fire is quickly
handled and extinguished in the easily stage, specifically at a place where huge damage
occurs when a fire breaks out, such as a mountain or an open storage yard. It is not
easy to put out the fire in the early stage in such a mountain or open storage yard
where a fire extinguish equipment is not well prepared, and even if the fire is found
early, early extinguishment may be failed due to backwardness and shortage of equipments.
[0004] Specifically, in case of a forest fire generated during a dry period, an extinguish
system is activated by mobilizing many manpower to prevent and extinguish a fire.
However, the forest fire is not effectively extinguished since very elementary and
primitive tools and methods, such as a method of covering the fire with dirt by using
a shovel or a pitchfork, are used as firefighting equipments, and only a spray type
manual fire extinguisher is used to put out a smoldering fire.
[0005] Similarly, in case of a fire occurred in an open storage yard without water, a narrow
alley, a traditional market, or the like, the most important thing is initial extinguishment,
but the initial extinguishment is difficult because it is impossible for a fire truck
to enter the open storage yard, the narrow alley, the traditional market, or the like.
[0006] Also, a car provided with a separate water tank, and a pump are required since water
cannot be supplied to grasses, trees, or the like because the fire truck cannot be
directly connected to an outdoor fire hydrant and an OC valve at a park or the like.
Accordingly, the present applicant has registered Korean Patent Registration
No. 1015060 about a small multipurpose sprinkler truck. However, in Korean Patent Registration
No.
1015060, a sealing unit is damaged as a pressure is increased between a chamber and a suction
unit, efficiency of a pump is decreased and thus a negligence accident is occurred
as a flow rate changes as time passes, and a lifespan of the pump is decreased as
durability of a valve and subsidiary apparatus is deteriorated due to a donut phenomenon
according to flow resistance.
SUMMARY OF THE INVENTION
[0007] The present invention provides a simple fire truck with easy movement, which easily
moves to a narrow fire occurred spot difficult for a car to enter by using a transfer
wheel driven by a motor separately from a pump driven by an engine, prevents a damage
of a sealing unit by depressurizing a pressure transferred to the sealing unit by
forming a groove between a chamber and a suction unit formed inside a pump, and improves
durability of a positive-displacement pump through lubrication and cooling by using
a lubricating water suction unit provided at a pump suction unit during an initial
activation.
[0008] According to an aspect of the present invention, there is provided a simple fire
truck that easily moves to a narrow fire occurred spot difficult for a car to enter
by using a transfer wheel driven by a motor separately from a pump driven by an engine,
the simple fire truck including: a depressurization groove that is formed between
a chamber where a sealing unit receiving pressure of the pump is provided, and a suction
hole, so as to depressurize a pressure of the chamber; a lubricating water supply
unit for improving durability through lubrication and cooling by supplying lubricating
water to an inlet of the chamber according to a vacuum pressure generated during an
initial activation of the pump; and a rotor unit having a first protrusion at an end
of a side of a rotor provided inside the chamber, and a second protrusion at a periphery
of a shaft hole through which a rotation shaft penetrates.
[0009] The lubricating water supply unit may include: a lubricating water tank provided
to be located above a chamber; a nozzle unit enabling the lubricating water to free-fall
according to gravity by being provided at a bottom of the lubricating water tank;
a supply valve provided at a top of the housing so as to supply or block the lubricating
water to the suction hole; and a filter provided between the lubricating water tank
and the nozzle unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and other features and advantages of the present invention will become
more apparent by describing in detail exemplary embodiments thereof with reference
to the attached drawings in which:
FIG. 1 is a perspective view showing an overall appearance of a simple fire truck
with easy movement, according to an embodiment of the present invention;
FIG. 2 is a view showing a structure for depressurizing a pressure inside a chamber
shown in FIG. 1;
FIG. 3 is a magnified view of a portion A of FIG. 2;
FIG. 4 is a graph showing pressures applied to sealing units of a general rotary displacement
type pump and of a rotary displacement type pump of the present invention including
a groove;
FIG. 5 is a cross-sectional view for explaining an installation structure of a lubricating
water supply unit according to an embodiment of the present invention; and
FIG. 6 is a perspective view of a structure of a rotor, according to an embodiment
of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Hereinafter, the present invention will be described more fully with reference to
the accompanying drawings, in which exemplary embodiments of the invention are shown.
Terms or words used herein should not be interpreted as being limited to common or
dictionary meanings, and based on a principle that the inventor can suitably define
a concept of a term to describe the invention the best way possible, the terms and
words should be interpreted to have meanings and concepts corresponding to the technical
aspect of the present invention.
[0012] Exemplary embodiments of the present invention will now be described with reference
to accompanying drawings, wherein FIG. 1 is a perspective view showing an overall
appearance of a simple fire truck with easy movement, according to an embodiment of
the present invention, FIG. 2 is a view showing a structure for depressurizing a pressure
inside a chamber shown in FIG. 1, FIG. 3 is a magnified view of a portion A of FIG.
2, FIG. 4 is a graph showing pressures applied to sealing units of a general rotary
displacement type pump and of a rotary displacement type pump of the present invention
including a groove, FIG. 5 is a cross-sectional view for explaining an installation
structure of a lubricating water supply unit according to an embodiment of the present
invention, and FIG. 6 is a perspective view of a structure of a rotor, according to
an embodiment of the present invention.
[0013] Referring to FIGS. 1 through 6, FIG. 1 is the perspective view of the overall appearance
of the simple fire truck with each movement, wherein a brake unit 700 that controls
rotation of a transfer wheel 500 driven by receiving power from a motor 400 operated
by receiving power of a battery is provided at a plate member 300 on which a pump
200 operated by being connected to an engine 100 that integrally includes a fuel tank
and operates the pump 200 by generating power is provided, and a frame member 600
including a handle for steering a direction of the transfer wheel 500 is provided.
[0014] A depressurization groove 200-6 is formed between suction hole 200-1 a and a chamber
200-1 to which a sealing unit 200-5 receiving pressure of the pump 200 is provided,
and the depressurization groove 200-6 depressurizes pressure of the chamber 200-1.
[0015] Referring to FIG. 4, a lubricating water supply unit 230 for improving durability
through lubrication and cooling by supplying lubricating water according to a vacuum
pressure generated during an initial activation of the pump 200 is provided at the
suction hole 200-1 a of the chamber 200-1.
[0016] A rotor 220 provided inside the chamber 200-1 has a structure where a first protrusion
220-1 is formed at a side end, and a second protrusion 220-2 is formed at a periphery
of a shaft hole through which a rotation shaft penetrates.
[0017] The lubricating water supply unit 230 includes a lubricating water tank 230-1 provided
at a top of the chamber 200-1, a nozzle unit 230-2 enabling the lubricating water
to free-fall according to gravity by being provided at a bottom of the lubricating
water tank 230-1, a supply valve 230-3 provided at the top of the chamber 200-1 to
supply or block the lubricating water to the suction hole 200-1a, and a filter 230-4
provided between the lubricating water tank 230-1 and the nozzle unit 230-2.
[0018] The lubricating water tank 230-1 is a storage container for storing predetermined
lubricating water, and stores an amount of lubricating water required at least to
initially activate the pump 200. Also, since the amount of lubricating water during
the initial activation differs according to capacity of the pump 200, the lubricating
water tank 230-1 having a suitable size for the capacity of the pump 200 may be provided.
[0019] The nozzle unit 230-2 is provided at the bottom of the lubricating water tank 230-1
so that the lubricating water is discharged outside the lubricating water tank 230-1
by gravity and vacuum pressure in the suction hole 200-1 a. Since an amount of lubricating
water during an initial activation of the nozzle unit 230-2 also differs according
to the capacity of the pump 200 like the lubricating water tank 230-1, the nozzle
unit 230-2 having a suitable discharge amount for the capacity of the pump 200 may
be provided.
[0020] When the simple fire truck with easy movement having such a structure according to
the present invention is to move to an ignition point or to a point to spray and supply
water by using the pump 200, the motor 400 provided at the plate member 300 integrally
formed with the frame member 600 is operated to rotate the transfer wheel 500 connected
to the motor 400, and the simple fire truck is moved by driving the simple fire truck
by using the handle for steering the direction of the transfer wheel 500, and the
brake unit 700.
[0021] Once the simple fire truck is moved to the ignition point or the point to supply
water, the engine 100 and the pump 200 are operated so as to point the flexible hose
toward a direction to spray and supply water, and then water is sprayed and supplied.
[0022] Here, looking at operations of the pump 200, when a fluid is sucked through the suction
hole 200-1a via rotation of the rotor 220, the fluid flowed into the chamber 200-1
is compressed via the rotation of the rotor 220 and is instantaneously exploded, and
thus the fluid is moved toward a discharge hole at a high pressure.
[0023] The fluid of high pressure gathered at the discharge hole is moved into the chamber
200-1 due to a change of volume inside the chamber 200-1 generated by the rotation
of the rotor 220, and then vacuum pressure is applied to the fluid of high pressure
below an abrasion plate 200-4.
[0024] When the fluid is discharged as such, lubricating oil may leak as the rotation shaft
rotates at a high speed, but such leakage is prevented by the sealing unit 200-5.
[0025] Looking at operations of the sealing unit 200-5, high pressure generated by the rotation
of the rotor 220 pressurizes the sealing unit 200-5 by leaking between the abrasion
plate 200-4 and the rotation shaft, and the abrasion plate 200-4 formed of a metal
is not deformed whereas the sealing unit 200-5 formed of a rubber material is compressed
and deformed. When the sealing unit 200-5 is compressed and deformed, removal of the
sealing unit 200-5 inside the chamber 200-1 is prevented by the abrasion plate 200-4.
[0026] Since the high pressure transferred to the sealing unit 200-5 is discharged toward
the suction hole 200-1a as shown in FIG. 4, the pressure inside the chamber 200-1
to which the sealing unit 200-5 is provided is instantaneously removed.
[0027] As shown in FIG. 4, pressure of about 2.0 ± 0.2 MPa is measured at a point where
the sealing unit 200-5 is provided in a conventional rotary displacement type pump
where the depressurization groove 200-6 is not formed between the chamber 200-1 and
the suction hole 200-1a, but pressure of about 1.2 ± 0.12 MPa is measured in the pump
200 of the present invention. Accordingly, the sealing unit 200-5 usable at maximum
pressure of 1.5 MPa, i.e., an inexpensive sealing unit, may be used while considering
a safety factor.
[0028] Referring to FIG. 5, in the rotor 220 that transfers the fluid according to gearing
of the rotor 220 being rotated, only the first protrusion 220-1 is formed at the side
of the rotor 220 in the chamber 220-1 to seal the rotor 220 being rotated and the
abrasion plate 200-4. Because the first protrusion 220-1 is formed at an edge of the
rotor 220 having a quick circumferential speed, seal force (hermetic force) is decreased
when the first protrusion 220-1 is worn away by friction between the abrasion plate
200-4 and the first protrusion 220-1 as the rotor 220 rotates for a long time, and
thus it is difficult to maintain airtightness for a long time as high pressure is
formed at a shaft sealing member.
[0029] Further, the first protrusion 220-1 and the abrasion plate 200-4 may be damaged as
a foreign substance inevitably flowed in during suction of the pump 200 is inserted
between the first protrusion 220-1 and the abrasion plate 200-4 while the first protrusion
220-1 rotates. Accordingly, the second protrusion 220-2 is formed near a shaft (a
center of a circle) in a circumferential direction besides the first protrusion 220-1,
and thus even if the first protrusion 220-1 having a quick circumferential speed is
worn away or short-circuited by the foreign substance, the second protrusion 220-2
functions as a sealing member, thereby excellently maintaining seal force.
[0030] The first protrusion 220-1 is directly exposed to the foreign substance flowed into
the pump 200 according to the rotation of the rotor 220, and the foreign substance
generates a short circuit of the first protrusion 220-1 or abrasion and short circuit
of the abrasion plate 200-4 by being inserted between the first protrusion 220-1 and
the abrasion plate 200-4 during rotation. Also, the first protrusion 220-1 is relatively
quickly worn away than the second protrusion 220-2 since the first protrusion 220-1
has a quick circumferential speed by being disposed at an outermost periphery (edge)
in a circumferential direction. However, the second protrusion 220-2 functions as
a sealing member for a long time as an abrasion speed of the second protrusion 220-2
is delayed since the second protrusion 220-2 is closer to a rotation center than the
first protrusion 220-1, and thus has a relatively slower circumferential speed (1/2
to 1/3 of the first protrusion 220-1).
[0031] Since the foreign substance is not easily led to the second protrusion 220-2, the
short circuit of the second protrusion 220-2 is prevented, and thus seal force is
improved.
[0032] The lubricating water supply unit 230 is activated before an initial activation of
the pump 200. Here, the lubricating water is pre-filled in the lubricating water tank
230-1 before a positive-displacement pump is driven.
[0033] Next, the supply valve 230-3 is opened to activate the positive-displacement pump.
Accordingly, vacuum pressure is formed inside, i.e., in a space portion, of the positive-displacement
pump according to the rotation of the rotor 220. The vacuum pressure sucks the lubrication
water to the suction hole 220-1 a through the nozzle unit 230-2. Then, the lubricating
water is continuously supplied from the suction hole 200-1 a to the rotor 220 as shown
in a silver line of FIG. 5. At this time, the lubricating water is discharged from
the lubricating water tank 230-1 to the suction hole 200-1 a by the vacuum pressure
and gravity.
[0034] Meanwhile, the lubricating water is supplied to the space portion along a bottom
of the suction hole 200-1 a and sucked between the suction hole 200-1 a and the rotor
220 to function as a priming water. Also, the lubricating water not only prevents
pressure in the positive-displacement pump from externally leaking but also cools
down frictional heat between the rotor 220 and the space portion.
[0035] The lubricating water supply unit 230 is configured such that a small amount of lubricating
water is supplied to a housing by vacuum pressure of an inlet, thereby performing
cooling and lubrication between the housing and the rotor 220. Accordingly, durability
of the positive-displacement pump is improved.
[0036] The present invention may be used in firefighting equipment for extinguishing fire.
[0037] The simple fire truck with easy movement according to the present invention has following
effects.
[0038] First, the simple fire truck can easily move to a small fire occurred spot difficult
for a car to enter, by using a transfer wheel driven by using a motor separate from
a pump driven by an engine.
[0039] Second, a damage of a sealing unit can be prevented by depressurizing pressure transferred
to the sealing unit by forming a groove between a suction unit and a chamber formed
inside the pump.
[0040] Third, durability of a positive-displacement pump can be improved through lubrication
and cooling by using a lubricating water suction unit provided at a pump suction unit
during an initial activation.
[0041] While the present invention has been particularly shown and described with reference
to exemplary embodiments thereof, it will be understood by those of ordinary skill
in the art that various changes in form and details may be made therein without departing
from the spirit and scope of the present invention as defined by the following claims.