Note: Descriptions are shown in the official language in which they were submitted.
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"A PUMP"
The present invention relates to a pump, more specifically, a
hydraulic one.
Description of the Prior Art
At present, there are different types of electro-mechanical pumps
used for driving fluids, generally constituted of a chamber containing the
electro-magnetic part, basically comprising the stator and the rotor armature,
as well as another chamber with a hydraulic part, basically formed of the
hydraulic turbine that drives the liquid. However, the electro-magnetic and
hydraulic chambers need to be insulated from each other so as to prevent
the liquid from reaching the stator and the rotor, causing short-circuits and
even irreparable damage. Thus, in order to achieve this insulation of the
chambers and transmission of rotation movement from the rotor to the
hydraulic turbine, several mechanical apparatus are required, such as an
axle, roller bearings, bearing journals, cooling systems, hydraulic seals,
among others.
The roller bearing journals, for instance, have the function of
supporting the rotor axle, on which the rotor cage is mounted, so that, when
the latter is induced by magnetic forces from the stator, the rotor turns,
assisted by these bearings. Of course, the journals are lubricated with oil or
grease so as to decrease friction and wear between the parts in contact.
One end of the rotor axle is connected to the hydraulic turbine,
formed of blades, which, upon induction of the rotor, begins a rotational
movement driving the liquid to be pumped.
To prevent the temperature of both the stator and the rotor from
reaching undesired levels during their functioning, external cooling systems
are used, usually constituted of ventilators. Such cooling systems generally
comprise propellers coupled to the end of the rotor axle, outside the pump
and opposed to the hydraulic pump, which, taking advantage of the rotation
of the rotor, turns to cool both the stator and the rotor.
The pumps of the prior art depend upon the perfect functioning of
the mechanical seals to prevent the liquid from passing from the hydraulic
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chamber into the electro-magnetic chamber. As already mentioned, this
undesirable contact of the liquid with the stator and rotor may cause short-
circuits, as well as a decrease in the lubrication of the journals, resulting
in
possible seizure of the rotor.
Therefore, one can verify the fact that the prior art pumps have
hydraulically insulated chambers, wherein an induced, rotor located in a
hermetically sealed chamber, transmits rotation by means of its axle to a
hydraulic turbine located in another liquid-passage chamber, making it
necessary for these pumps to have a number of sealing mechanisms to
prevent the occurrence of damage that might even render them useless. In
addition, with use the consequent wear of these mechanisms, such pumps
lose their mechanical efficiency. Thus, this combination has the drawback of
entailing high costs, because it involves expensive parts, a complex
manufacturing process and constant maintenance to keep such pumps
functioning.
In view of this, the main objective of the present invention is to
simplify the composition of a traditional pump by eliminating sealings, such
as mechanical seals or gaskets, as well as roller bearings, axles and external
cooiing systems, such as ventilators, thereby reducing the chance of the
pump being damaged. This new pump motor further provides cooling of the
stator-rotor assembly by circulating the pumped fluid itself, as described in
patent application Pi 0004206-4.
In addition, the invention also has the objective of providing a
new pump that is more compact than the present ones, easy to manufacture
and assemble, by virtue of its smaller number of components, thus resulting
in better automation and cost reduction.
Another objective of the present invention is to provide a pump
that is more efficient, that is, presenting lower energy loss.
In addition, the invention aims at providing a safer, more
protected and corrosionproof pump motor, enabling immersion and
installation in environments that are aggressive and without cooling.
A further objective of the present invention is to provide a pump
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with a very low noise level and lubrication provided by the circulating fluid
itself.
Summary of the Invention
The present invention achieves all these objectives by means of
a pump comprising a casing, having at least one first hermetically sealed
chamber and at least one second chamber adjacent to said first chamber,
provided with a fluid passage and having an inlet and an outlet for fluids.
Said
chambers are separated by means of walls, preferably made of injected
polymer.
The pump further comprises a stator located in the first chamber.
In a preferred embodiment, the stator is in a position adjacent to the walls
that separate the first chamber from the second, so that the fluid circulating
through the second chamber will cool it by heat transmission.
An integral rotor-turbine assembly, wholly located in the second
chamber, is provided, and at least a portion of said assembly is positioned
concentrically in relation to the stator. This assembly is induced by the
stator
to drive a fluid from the inlet to the outlet. When the pump is functioning,
at
least a fluid film is maintained around the assembly, in order to bring about
perfect rotation with minimum friction and without any need for journals. The
space between said assembly and the stator, called a gap, is substantially
filled with said walls of the first and second chambers, including,
furthermore,
the fluid film circulating between them.
A metallic component, called the rotor cage, preferably
composed of iron and aluminium, capable of being induced by the stator, is
provided inside the hermetically sealed assembly. In the preferred
embodiment, such an assembly is made from polymeric material and is
additionally bored through to provide a passage for the turbine inside the
rotor. In possible embodiments of the present invention, the turbine of said
assembly is composed of turbine blades to centrifuge the fluids. In this way,
upon functioning of a possible embodiment of the pump, the fluid, after
passing through the inlet of the second chamber, goes into the rotor-turbine
assembly, passes through the internal passageway and, after reaching the
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turbine blades, is driven towards the outlet.
However, a portion of the fluid, instead of coming out
directly through the outlet, circulates around the first chamber and cools
the stator by heat transmission. In this way, the need for an external
cooling system is eliminated, since the heat exchange between the
circulating fluid and the driving assembly will result in cooling this
assembly, so that its temperature will always preferably remain at
desirable levels for its good functioning.
In addition, the circulating fluid is also used as a lubricant.
A film of circulating fluid will pass between the walls of the second
chamber and the rotor-turbine assembly, allowing the latter to make a
floating rotary movement within the second chamber by virtue of the
inducing forces.
One aspect of the present invention is a centrifugal
hydraulic pump comprising: a casing having at least one first
hermetically sealed chamber, and at least one second chamber adjacent
to said first chamber, defining a passageway for fluids and having an
inlet and an outlet for the fluids, the first and second chambers being
separated from each other by walls; a stator located in said first
chamber; a rotor-turbine assembly with rotor and turbine, and being
capable of being induced by the stator to drive a fluid from the inlet to
the outlet, at least a portion of said assembly being positioned
concentrically with respect to the stator, wherein the rotor and the
turbine are integral and are wholly located in the second chamber, so
that, when in operation, a film of fluid will be maintained around said
assembly to provide a support therefor, and wherein said rotor-turbine
assembly is bored through, defining an internal fluid passageway;
wherein said integral rotor-turbine assembly is supported in said pump
bearing-free.
In view of the foregoing, the pump of the present invention
provides a simpler configuration with less expensive manufacture, since
it is basically composed of an induction means and a movement-
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transmission means similar to those of the prior art, such as stators and
rotors, which eliminate the use of a ventilator, as well as roller bearings,
axles and mechanical seals.
Brief Description of the Drawings
The present invention will now be described in greater detail
with reference to the drawings.
Figure 1 is a cross-section side view of a typical pump
motor of the prior art; and
Figure 2 is a cross-section side view of the device for
driving fluids of the present invention.
Detailed Description of the Figures
Figure 1 shows a present-day pump, encountered in the
prior art, comprising a coiled stator 4, a rotor 5 and roller bearings 3,
which support the axle 9 on which the cage of said rotor 5 is mounted.
The axle 3 will be responsible for transmitting driving force from the rotor
5 by means of induction of the magnetic field of the stator 4. One can
also note in this figure the existence of a ventilator 1, which is
responsible for cooling the stator-rotor assembly, and of covers 2
located on both sides of the rotor 5, which support
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said roller bearings.
In addition, in order to achieve a good functioning of this type of
pump motor, the rotor 5 has to be perfectly centered with respect to the
stator
4, so as to avoid contact between their magnetic iron. In the pump motor
5 represented in figure 1, this space between the rotor 5 and the stator 4,
called a gap, is filled with air.
Figure 1 further illustrates mechanical seals 8, which are widely
used in the pump motors of the prior art, to guarantee ventilation and
separation between the electric part and the hydraulic part of the pump
motor, the hydraulic part being constituted of the turbine 7 and the volute 6.
Figure 2, on the other hand, illustrates a preferred embodiment of
the present invention, in which some of the elements shown in figure 1 are
absent. This embodiment illustrates a pump 10 comprising a casing 14
having a first hermetically sealed chamber 19 and a second internal chamber
17 with at least one inlet 15 and one outlet 16 defining the passageway 18
between said inlet and outlet. The casing 14 may be made from a polymeric
material or any other type of material suitable for the specified conditions,
including bad weather.
An integral rotor-turbine assembly 11 is located in the chamber
17 to drive the fluids that pass through said chamber. This assembly is made
from a polymeric material and, in addition, is bored through to define a
passageway for the turbine inside the rotor. In this embodiment, the turbine
of said assembly is composed of blades for centrifuging the fluids. In this
way, when in operation, the fluid, after passing through the inlet 15 of the
chamber 17, goes into the rotor-turbine assembly 11, passes through the
internal passageway, and, after reaching the turbine blades, is driven toward
the outlet 16.
The casing 14 also has a first chamber 19, hermetically sealed
from the fluids that circulate through the second chamber 17. Both the
extemal walls of the casing and the walls that separate the second chamber
17 from the first chamber 19 are formed of injectable polymeric material. In
addition, the stator 12, which may be any one of those known from the prior
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art, is installed in this first chamber 19 to induce, by means of a magnetic
field, the driving of the rotor-turbine assembly 11, located in the second
chamber 17 of fluid circulation.
This embodiment of the pump of the present invention also has
its second chamber 17 defining passageways other than that going from the
inlet to the outlet, so that a portion of the fluids will circulate through
this
chamber. Such passageways in this embodiment cause the fluid to circulate
around the first chamber 19, cooling the stator 12 located therein by heat
transmission.
In addition, a small portion of the fluid that enters inlet 15 and
circulates through the second chamber 17 passes through the
communication means 13 between one of the walls of the second chamber
17 and the rotor-turbine assembly 11, creating a constant fluid film, which
enables this assembly to tum freely submerged in the liquid, without having
any contact with the walls of the second chamber 17 while the pump is
functioning. In this way, such a film acts as a support for the assembly 11
and, at the same time, as a lubricant that virtually eliminates friction
between
the walls of the second chamber and of the assembly 11, further resulting in
a very low noise level. Although the assembly 11 is submerged in the liquid,
without contact with the walls of the second chamber 17, the magnetic field
created by the stator 12 maintains the former in a balanced position around
its axle, so that, upon rotational movement, the magnetic forces prevent the
assembly from contacting the walls of the second chamber 17.
In view of the foregoing, since the second chamber 17 has
passageways that enable the liquid to circulate through it, a reduction in
noise level is achieved, and this also eliminates the need for industrial
lubricants and external cooling systems. Since the pump is basically
composed of an injectable polymeric material and there is a decrease in the
number of components (i.e. does not include seals) in comparison with those
of the prior art, it becomes simpler and less expensive to assemble. In
addition, the energy losses are minimised by the low friction between the
rotor-turbine assembly 11 and the walls of the second chamber 17.
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Another important aspect of the present invention is that the
space between the stator 4 and the rotor 5 of the pumps of the prior art, the
so-called gaps, are filled with air. In the present invention, on the other
hand,
in addition to the liquid layer 13, there is the polymeric wall of both the
second chamber 17 and the rotor-turbine assembly 11, guaranteeing a
perfect centering of the magnetic materials of the stator 12 and the assembly
11, as well as a better balanced position of the latter around its axle, so
that,
upon rotation, contact with the walls of the second chamber 17 will be
avoided.
In addition, the present invention also provides a non-corrosive
pump, since only the surface covered with polymer will have contact with the
fluid. Therefore, the latter may be aggressive without causing any damage to
the pump motor. In addition, since the liquid itself is used as a coolant, the
pump of the present invention may be installed in environments without
ventilation or even submerged.
Having described an example of a preferred embodiment of the
invention, it should be understood that the scope of the present invention
embraces other possible variations, being limited only by the contents of the
accompanying claims.
