CA2201987C - A device with coaxial, opposite, modular pistons with double eccentric cams or similar, for floated pumps - Google Patents

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.

Description

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.

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.

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 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.

Claims (5)

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 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.