A DEVICE WITH COAXIAL, OPPOSITE, MODULAR PISTONS WITH DOUBLE ECCENTRIC CAMS OR SIMILAR, FOR FLOATED PUMPS

DISPOSITIF COMPOSE DE PISTONS MODULAIRES COAXIAUX, MONTES EN VIS-A-VIS, A DOUBLE CAMES EXCENTRIQUES OU DE TYPE SIMILAIRE, POUR POMPES A FLOTTEUR

English Abstract

A device for floated pumps with coaxial, opposite,
modular pistons (7), operated by double eccentric cams (5),
comprises pumping groups operating in parallel onto one and
the same working chamber communicating with safety valves
- one for suction and one for sending - and they may be
aligned, kept together by tie-rods in higher or lower
number, thus allowing differentiated flows and consequently
differentiated powers.
Said pistons (7) have a large diameter and a short
run, and their sealing is determined by elastomeric,
flexible membranes (8) resting on bevellings which assure
the functioning thereof, even under high pressures.
Also said valves (17, 20) of the pump are formed with
elastomeric, flexible membranes onto thin slits, which are
efficient also under high pressures.

Claims

5
CLAIMS:
1. A device with coaxial, opposite, modular pistons,
operated by double eccentric cams or similar for floated
pumps, characterized in:
- a segment, with a lower block, where a driving shaft
arrives, provided with a sealing gasket and with ball
bearings, whereby said driving shaft is in turn
provided with double counterposed eccentric cams;
- a plurality of modules, consisting of pistons with an
annular membrane, a piston carrying block, operated by
rollers with pins, springs and external bushings,
aligned with said bearings coaxially around said
shaft, and with the assembling tie-rods, to the
closing determined by the upper cap;
- an upper segment that shapes the working chamber,
surmounted by valves made from elastomeric material
for a water inlet from outer openings, through holes,
and from outlet valves, for adjusting passage from the
holes to outlet piping.
2. A device according to claim 1, characterized in that said
pistons pump water in a perfect sealing due to the
presence of said annular membranes and because of their
considerable surface, also for small movements, due to
the high rotation speed of said shaft, determine the
realization of pressures and depressions inside said
working chamber, with consequent opening and closing of
the elastomeric membrane valves, and the pumping of the
water.
3. A device according to claim 1, characterized in the
presence of extremely small bearings and with a minimum
energy absorption, due to the symmetry and balance of the

6
movement of said alternative pistons with respect to said
shaft.
4. A device according to claim 1, characterized in that half
the internal volume of each pumping module is provided
filled up with lubricating oil that is shaken by the
movement of the component parts.
5. A device according to claim 1, characterized in that it
has a pressure surplus, useful for application in the
depuration by inverse osmosis.

Description

CA 02201987 1999-11-26
1
A DEVICE WITH COAXIAL, OPPOSITE, MODULAR PISTONS WITH DOUBLE
ECCENTRIC: CAMS OR SIMILAR, FOR FLOATED PUMPS
The present invention concerns a device with coaxial,
opposite, modular pistons, operated by double eccentric cams
or similar for floated pumps, of the kind that may be
applied also to small diameter wells, so as to absorb small
powers even if showing a high efficiency for high
prevalence.
At present, floated pumps are known of the centrifugal
kind, which are undoubtedly efficient, but which may not be
realized, if the preval_ences are high, for powers lower than
a determined practical level (500-750 watt).
Consequently, for great prevalences, with lower power,
it seems to be necessary to make use of volumetric pumps
that may be floated in wells, but no volumetric pump of
small encumbrance is known at present. A few attempts have
been made but without ~;uccess, due to the great complication
and fragility.
It is an object of the present invention to realize a
floated pump of low power and high efficiency, for great
prevalences.
The object set forth is achieved by means of the device
for floated pumps according to the present invention, with
coaxial, opposite, modular pistons, operated by double
eccentric cams or similar.
Said pumping groups according to the present invention,
operate in parallel onto one and the same working chamber
communicating with safety valves - one for suction and one
for sending - and they may be aligned, kept together by tie-
rods in higher or lower number, thus allowing differentiated
flows and consequently differentiated powers.

CA 02201987 1999-11-26
2
According to the present invention, the pistons have a
large diameter and a short run, and their sealing is
determined by elastomeric, flexible membranes resting on
bevellings which assure the functioning thereof, even under
high pressures.
In a similar way, the valves of the pump are realized
with elastomeric, flexible membranes onto thin slits, which
are efficient also under high pressures.
The device according to the present invention has the
following relevant advantages:
- no practical limit inherent to the pressures;
- a high efficiency, typical of volumetric pumps;
- low friction and small mechanical losses;
- balanced internal and external forces;
- no vibrations;
- simplicity, robustness, high efficiency;
- a small diametrical encumbrance, possibility of an overall
lengthened cyli:ndric shape, that may be floated in wells
of small diameter;
- modular capacities and therefore power, without any lower
practical limit;
- possibility of realization in small dimensions, according
to the needs;
- particular fitness to applications fed with solar energy,
or applications with low power.
The present invention will be described more in detail
hereinbelow relating to the enclosed drawings in which an
embodiment thereof is shown.

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Figure 1 shows a vertical scheme of a device with
coaxial, opposite, modular pistons according to the present
invention, operated by double eccentric cams or similar, for
floated pumps.
Figure 2 shows a section A-A of said Figure 1.
Figure 3 shows an exploded axonometric view of the
components.
The enclosed figures show a device for floated pumps,
with a preferably cylindric shape, comprising:
- a segment 1, with a lower block 2, where the driving shaft
A arrives, provided with a sealing gasket 3 and with ball
bearings 4, whereby said shaft is in turn provided with
double counterposed eccentric cams 5;
- a plurality of modu_Les, consisting of pistons 7 with an
annular membrane 8, a piston carrying block 9, operated by
the rollers 10 with pins 11, springs 12 and external
bushings 13, aligned with said bearings 4 coaxially with
said shaft A, a:nd with the assembling tie-rods 6, to the
closing determined by the upper cap 14;
- an upper segment 15 that shapes the working chamber 16,
surmounted by valves 17 out of elastomeric material for
the water inlet from the outer openings 18, through holes
19, and from the outlet valves 20, for adjusting the
passage from th~~ ho:Les 21 to the outlet piping 22.
For what concerns the functioning of the pump according
to the present invention, the rotation of the shaft A
determines the one of the cams 5 of each module and, by
means of rollers 10, the alternate movement of said pistons
7 which, being perfectly sealed due to the presence of said
annular membranes 8 and. because of their considerable

CA 02201987 1999-11-26
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surface, also for small movements, due to the possible high
rotation speed of said shaft A, determine the realization of
pressures and depressions inside said working chamber 16,
with consequent o,oening and closing of the elastomeric
membrane valves 17 and 20, and the pumping of the water
according to the abject set forth.
It shall be underlined that, when the known floated
pumps are driven by solar energy and when the engine changes
it speed due to t:he variation of the insulation, also the
functional features change and show a modification in the
prevalence; while in similar conditions, the pump according
to the present invention has a change in the flow but keeps
its prevalence constant.
Beyond the already described advantages, the pump shown
in the enclosed figures has extremely small bearings 4,
characterized by a consequent low energy absorption, because
it is symmetric a:nd balanced in such a way as not to
determine axial pushes onto said shaft A of the engine, as
said pushes usually force said bearings.
Among the possible applications, the pump according to
the present invention may be used in the depuration by
inverse osmosis, exploiting it pressure surplus.
Finally, it is provided that half the internal volume
of each pumping module is filled up with lubricating oil
that is shaken by the movement of the component elements.

Representative Drawing