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Title:
HYDRAULIC, ELECTROMAGNETIC FLOATING-PISTON MOTOR PUMP
Document Type and Number:
WIPO Patent Application WO/2018/224903
Kind Code:
A1
Abstract:
A floating-piston motor pump comprises a body delimited by a coil, an inlet duct and an outlet duct, a sliding piston and a magnetic sleeve coaxial to the sliding axis of the piston; the magnetic sleeve interacts with the pair of magnetic bearings to increase the magnetic attraction force exerted on the piston and there are also noise-decreasing means operatively active and located between the magnetic sleeve, the piston and the body.

Inventors:
PALMIERI ROBERTO (IT)
BENINI MICHELE (IT)
Application Number:
PCT/IB2018/053601
Publication Date:
December 13, 2018
Filing Date:
May 22, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
CEME SPA (IT)
International Classes:
F04B17/04; F04B53/00
Foreign References:
EP2122167B12011-02-23
EP0288216A11988-10-26
US20080314238A12008-12-25
DE102008008904A12009-08-20
EP1365149A22003-11-26
US20130034459A12013-02-07
Attorney, Agent or Firm:
TARABBIA, Luigi (IT)
Download PDF:
Claims:
CLAIMS

1 . Floating-piston motor pump (10) of hydraulic, electromagnetic type, comprising:

- a body (12) which is partially delimited, in its outer part, by a coil (14); - an inlet duct (44') and an outlet duct (36) opposite to said inlet duct (44') obtained in said body (12);

- a piston (16) slidably placed inside the body (12); and

- a magnetic sleeve (52) having a first end placed inside said container body (12) in a part thereof facing the inlet duct (44') and arranged coaxially to the sliding axis of the piston (16), said first end of said magnetic sleeve (52) coupling to the body (12) of the container in an intermediate part (42) thereof adjacent to a terminal part (44) of the body (12) defining the inlet duct (44'), said magnetic sleeve (52) interacting at least with the coil (14) to increase the magnetic field and, therefore, the magnetic attraction force exerted on the piston (16),

characterized in that it also comprises noise-decreasing means operatively active and located at least between the magnetic sleeve (52), the piston (16) and the body (12).

2. Motor pump according to claim 1 , wherein the is also a pair of opposite magnetic bearings (46, 46') spaced between them and placed between the body (12) and said coil (14), said pair of opposite magnetic bearings (46, 46') being arranged coaxially to a sliding axis (16a) of the piston (16) and interacting with the piston (16) and/or the magnetic sleeve (52) to increase the magnetic field and, therefore, the magnetic attraction exerted on the piston (16), said noise-decreasing means being operatively active also between the magnetic bearings (46, 46') and the magnetic sleeve (52) and between the piston (16).

3. Motor pump according to claims 1 or 2, wherein said noise-decreasing means comprise at least one passive kinetic and/or acoustic absorption element (100) placed at the end strokes of the piston (16) and suitable to suffer an impact by the piston (16) itself.

4. Motor pump according to claim 3, wherein said at least one passive kinetic and/or acoustic absorption element (100) comprise a body, preferably an annular body, made of polymeric material and still more preferably made of material having hyperelastic behavior.

5. Motor pump according to any one of the preceding claims, wherein the noise-decreasing means comprise at least one active prevention assembly (200) to actively prevent shocks and/or impacts, which is operatively active near at least one end of the piston (16) to prevent material impacts or contacts with the body (12) and/or the magnetic sleeve (52) and/or magnetic bearings (46, 46'), said active prevention assembly (200) being able to exploit vector variations of magnetic interactions between the piston (16) and the body (12) and/or between the piston (16) and the magnetic sleeve (52) and/or between the piston (16) and the magnetic bearings (46, 46') suitable to slow down and/or brake the piston (16) itself in correspondence of at least one threshold point of its stroke along the sliding axis (16a).

6. Motor pump according to claim 5, wherein the active prevention assembly (200) comprises:

- a first interaction portion (200a) formed on the piston (16) preferably at one end thereof; and

- a second interaction portion (200b) placed near said first interaction portion (200a) at an end of stroke of the piston (16) and preferably formed in the magnetic sleeve (52) and/or in the magnetic bearings (46, 46') and/or in the body (12),

Said first and second interaction portions (200a, 200b) being mutually interacting to define variations of magnetic vector interactions suitable to brake and/or slow down the piston (16).

7. Motor pump according to claim 6, wherein the first and second interaction portion (200a), (200b) are complementary shaped and, preferably, are geometrically interpenetrating into each other along the sliding axis (16a).

8. Motor pump according to claim 7, wherein the first interaction portion (200a) comprises a protrusion or a cylindrical or annular cavity placed on one end of the piston (16), the second interaction portion (200b) complementarily comprising a cavity or a cylindrical or annular protrusion placed on the magnetic sleeve (52) and which can be circumscribed or inscribed in said protrusion or cavity of the first interaction portion (200a).

9. Motor pump according to any one of the preceding claims, wherein the piston (16) is supported by a front coil spring (20) and a rear coil spring (20') placed inside the body (12).

10. Motor pump according to any one of the preceding claims, wherein the body (12) comprises:

- a front wall (40) having a larger diameter facing the outlet duct (36);

- an adjacent intermediate part (42) having a diameter smaller than that of said front part (40) and delimiting a sliding chamber of the piston (16); and - a terminal part (44) having a diameter smaller than that of said intermediate part (42), said terminal part (44) defining the inlet duct (44'). 1 1 . Motor pump according to claims 9 or 10, wherein an outer side surface of the magnetic sleeve (52) comprises:

- a rear area (54) facing the duct (44') and having a diameter equal to or slightly less than an inner diameter of the intermediate part (42) of the body (12); and

- an adjacent front area (56) facing the outlet duct (36) and having a diameter smaller than that of said rear area (54), said areas (54) and (56) defining a coupling shoulder (58) for the rear spring (20').

12. Motor pump according to any one of the preceding claims, in which the first end of the magnetic sleeve (52) couples with the body (12) in the intermediate part (42) adjacent to the narrowing of the terminal part (44) defining the inlet duct (44'), the distance between an opposite end of said sleeve (52) and the piston (16) being smaller than the distance between the latter and the one or the other of the two magnetic bearings (46, 46') when placed in the position which is reached by the piston (16) during the loading step of the rear spring (20').

13. Motor pump according to any one of the preceding claims, wherein the magnetic sleeve (52) is made of a steel having a low residual magnetic content.

Description:
DESCRIPTION

HYDRAULIC, ELECTROMAGNETIC FLOATING-PISTON MOTOR

PUMP

The present invention relates to a hydraulic, electromagnetic floating- piston motor pump, and more particularly the present invention relates to a hydraulic, electromagnetic floating-piston motor pump suitable for moving fluids such as water.

This type of motor pump is applied to various devices such as flat irons, electric coffee machines, irrigation systems and also in the automotive industry: for example, electromagnetic hydraulic motor pumps with floating piston are known from EP-A-1 205 663, US-A-4 749 343; EP-A-1 001 167 and EP-A-0 288 216 (and more particularly, EP-A-1 205 663 discloses a hydraulic, electromagnetic floating-piston motor pump having the features of the preamble of claim 1 ).

The operation of this type of motor pump is based on the presence of a coil that cooperates with a pair of magnetic bearings: the coil is electrically powered and causes the axial movement of the floating piston or of the piston with alternating motion.

The same applicant has also made available in the State of the Art a particular type of floating-piston motor pump, wherein a magnetic sleeve is also present, which cooperates functionally with the remaining "magnetically active" parts of the motor pump itself to improve the magnetic field interactions, thus improving the kinematics / dynamics of the floating piston itself and therefore increasing the performance of the motor pump at least in terms of the level of higher pressure achievable while maintaining a very low total encumbrance of the motor pump itself (and equally low production costs).

However, the known motor pumps disclosed hitherto are in any case affected by noise-related drawbacks: in fact, it is possible that in particular working conditions the floating piston, during its stroke, abuts in a more or less controlled manner on the other parts of the motor pump, thus generating acoustic waves that can also be at high frequency (and therefore in a perceived tone that is particularly annoying) or, in any case, having high sound intensity.

Therefore, the object of the present invention is to overcome the above- mentioned drawbacks, and more particularly, the present invention relates to the implementation of a hydraulic, electromagnetic floating-piston motor pump wherein the noise level generated during normal operation (but also during possible working moments in which the stroke of the floating piston is "anomalous") is considerably reduced both in terms of acoustic volume and of sound characteristics (frequency, duration and possible resonance phenomena).

A further object of the present invention is that of providing a motor pump of the type which can guarantee a high level of resistance and reliability over time, which is easily manufactured and which can be made starting from minimal modifications (both of the device and of the production line), with respect to other types of motor pumps already available.

According to the present invention, these and other objects are obtained by a motor pump according to the invention, illustrated in the following exemplifying - and for this reason not limiting - figures in a possible embodiment thereof, where the figures themselves represent:

- Figure 1 is a schematic exploded view of the motor pump of the Applicant already part of the State of the Art and which serves as a basis for the technical improvements introduced in the present invention;

- Figure 2 is a cross-sectional schematic view of a motor pump according to the present invention in a first operating configuration thereof; and -

Figure 3 is a cross-sectional schematic view of a motor pump according to the present invention in a second operating configuration thereof.

With reference to the figures, the motor pump of the present invention is generally indicated with the reference numeral 10 and basically comprises the following structural components:

- a body 12 which is partially delimited, in its outer part, by a coil 14; - an inlet duct 44' and an outlet duct 36 opposite to the inlet duct 44' obtained in the body 12;

- a piston 16, slidably placed inside the body 12; and

- a magnetic sleeve 52 having a first end located inside the body 12 and more precisely in its part facing the inlet duct 44'.

In greater detail, the first end of the above-mentioned magnetic sleeve 52 is arranged coaxially with the sliding axis of the piston 16 so as to couple with the body 12 in its intermediate part 42 (i.e. near the terminal part 44 which defines the inlet duct 44'): at the same time, the magnetic sleeve 52 can interact functionally with the body 12 - if necessary - to increase the overall magnetic field and, therefore, in order to increase the magnetic attraction force exerted on the piston 16.

Going deeper in the details and referring to Figure 1 , it can be seen that the motor pump of the State of the Art represented therein further comprises a pair of magnetic bearings 46, 46': these magnetic bearings are spaced apart from each other and placed between the body 12 and the coil 14 and at the same time this pair of magnetic bearings is arranged coaxially to a sliding axis 16a of the piston 16, interacting functionally with the piston 16 and / or with the magnetic sleeve 52 to increase the magnetic field and, therefore, the force of magnetic attraction exerted on the piston 16.

On the other hand, Figures 2 and 3 show a motor pump according to the invention, where the magnetic bearings 46, 46' are not visible: in any case, these two structural components (and in the same way, the coil 14, in turn not shown in Figures 2 and 3 but implicitly present in the structure of the invention, and in any case structurally and functionally able to be positioned / coupled at least with the body 12 and/or with the piston 16 according to well-known methods to a person skilled in the art dealing with designing and realizing oscillating cursor motor pumps) can be considered as optional structural features of the present invention and, if present, they are located with respect to the body 12 and/or to the sliding axis 16a of the piston 16, in the most suitable way in order to increase the magnetic interaction with the piston 16 and therefore to increase the flow and/or pressure performances of the motor pump 1 .

In greater detail, it can be seen that the coil 14 and the pair of magnetic bearings 46, 46' can be implemented in a similar way to that shown in Figure 1 also in motor pumps having the geometric / structural arrangement of the remaining components according to the invention and more precisely according to Figures 2 and / or 3 (or they can however be implemented according to a structural and functional coupling method which is well known to a person skilled in the art dealing with designing and realizing oscillating-cursor motor pumps).

Conveniently, where the embodiments of the present invention provide for the presence of the magnetic bearings 46, 46', the noise-decreasing means will be operationally active also between the magnetic bearings 46, 46', between the magnetic sleeve 52 and between the piston 16 (and of course between the coil 14).

Advantageously, the motor pump 10 according to the invention further comprises noise-decreasing means operatively active and located between the magnetic sleeve 52, the piston 16 and the body 12 (and optionally, if present, also active between the structural elements mentioned above and the magnetic bearings 46, 46'): such noise- decreasing means are suitable to prevent impacts or shocks of the piston 16 on the other parts of the motor pump 10 or, in the event that these shocks or impacts occur despite the "preventive" technical measures, they are suitable to absorb and contain - at least partly - the acoustic energy generated as a result of such shocks or impacts.

From a structural point of view, the noise-decreasing means mentioned above comprise at least one passive kinetic and/or acoustic absorption element 100, which is positioned at end strokes of the piston 16 and suitable to suffer an impact by the piston 16 itself: this passive kinetic and/or acoustic absorption element 100 comprises a body, preferably an annular body, made of polymeric material and still more preferably made of a material having hyperelastic behavior (therefore it can conveniently be made of natural or synthetic rubber based materials, or in any case made of materials able to absorb or dissipate the energy of the shocks/impacts of the piston 16, partially or wholly dampening the acoustic waves deriving from these phenomena).

In other words, it can be seen that the passive kinetic and/or acoustic absorption element 100 interposes between the piston 16 and one or more of the other structural components of the motor pump 10 at least in correspondence to an "end of stroke" reaching time of the movement of the piston 16 itself.

While the passive kinetic and/or acoustic absorption element 100 is active in its function only when the piston 16 strokes reach a geometrically undesired point, suitable "active/preventive" noise-decreasing means can also be present in the invention: these means comprise at least one active prevention assembly 200 for shocks and/or impacts which results to be active near at least one end of the piston 16 to prevent impacts or material contacts of the same with one or more of these components:

- the body 12; and/or

- the magnetic sleeve 52; and/or

- the magnetic bearings 46, 46' (if present).

From the functional/operational point of view, the active prevention assembly 200 mentioned above is suitable to exploit particular changes (or variations) of direction (and, if necessary, also of module) of the vectors resulting from the magnetic interactions between the piston 16 and the body 12 and/or between the piston 16 and the magnetic sleeve 52 and/or between the piston 16 and the optional magnetic bearings 46, 46': such magnetic interactions, which, as mention above, vary in the vector direction, occur in particular when the piston 16 crosses a certain threshold point of its stroke, defining a new balance of forces in which the attractive magnetic component along the sliding axis 16a decreases and in which, therefore, the stroke of the piston 16 is braked.

Thanks to the suitable positioning and sizing of the active prevention assembly 200, it is therefore possible to control the end parts of the piston 16 strokes, at least near the maximum geometrical ends of strokes established by the dimensions of the body 12, so as to stop and invert the motion of the piston 16 itself before it impacts the structural components on which it has impacted - therefore "producing a sound" -.

In greater detail, it can be seen that the active prevention assembly 200 comprises a first interaction portion 200a formed on the piston 16, typically at one of its ends, as well as a second interaction portion 200b located near the first interaction portion 200a and always at an end of stroke of the piston 16 but which, in turn, is formed in the magnetic sleeve 52 and/or (if present) in the magnetic bearings 46, 46' and/or in the body 12.

From the functional point of view, and, more precisely, from the mutual interaction point of view, the first and second interaction portions 200a, 200b mutually interact to define a vector variation of the magnetic interaction forces suitable to brake and/or slow down the piston 16.

According to the exemplary embodiment shown in the figures, the first and second interaction portions 200a, 200b can conveniently be complementary shaped, and e.g. They are geometrically interpenetrating into each other along the sliding axis 16a: this mutual complementary geometric configuration allows an interpenetration degree without contact when the piston 16 is moving, so as to be able to expose the piston 16 itself to the suitable magnetic field lines "varied in the slowing down/braking direction" but without generating mechanical contacts which, in turn, generate noise.

Still with reference to the figures, it can be seen how the first interaction portion 200a comprises - for instance - a cylindrical or annular protrusion (or, on the contrary, a cavity, not shown) placed on one end of the piston

16, while the second interaction portion 200b complementarily comprises a cylindrical or annular cavity (or, on the contrary, a protrusion, not shown) placed on the magnetic sleeve 52 and which can be circumscribed or inscribed in the protrusion or cavity of the first interaction portion 200a. As already described previously, the motor pump 10 comprises, in its basic structure, an inlet duct 44', an opposite outlet duct 36; a body 12 (partially delimited, in its outer part, by a coil 14), optionally a pair of opposite magnetic bearings 46, 46' which are spaced from each other and placed between the body 12 and the coil 14, a piston 16 which is placed inside the body 12 and flowing therein (resiliently supported by a front coil spring 20 and a rear spring 20'). In front of the piston 16, in the part facing the delivery duct, a sealing valve and an elastic band of the piston 16 are commonly placed: the elastic band and the sealing valve cooperate with a support bearing and a rubber sealing gasket which is elastically stretched by an additional coil spring.

The coil spring mentioned above and, at least partially, the rubber gasket are housed inside a seat of the delivery duct whose diameter is suitable to house the assembly formed by the rubber gasket and the coil spring (generally this diameter is greater than that of the outlet duct or hole of the delivery duct).

A locking ring 38 with an internal thread that engages with a suitably counter-shaped part (the latter can also be threaded, depending on the needs of the more or less "reversible" connection torque) in the outer part of the container body 12 is placed on the duct 22 according to the currently known technical methods.

For its part, the tubular body 12 comprises a front part 40 with a larger diameter which faces the outlet duct 36, an adjacent intermediate part 42 (with a diameter smaller than that of the front part 40) which delimits the sliding axial chamber of the piston 16 and a terminal part 44 whose diameter is extremely smaller than that of the intermediate part 42 which defines the inlet duct 44'. The opposite magnetic bearings 46 and 46' can be conveniently spaced from each other by the use of a spacer element and, if necessary, are adapted on the outer side surface of the intermediate part 42 of the body 12: at the same time, the coil 14 is, in turn, adapted on the body 12 so that it can include any magnetic bearings 46, 46'.

The coil 14 is stabilized with known technical means, which are made, e.g., of a shaped elastic ring which is coupled with a face of the coil and a shoulder (which can be seen in Figure 1 with the reference number 50) placed on the body 12 (such coupling is, e.g., located between the front part 40 and the intermediate part 42, with a smaller diameter which is coupled with the opposite face).

Inside the body 12 and, more precisely, in the central-lower part facing the inlet duct 44', the magnetic sleeve 52 is housed, which can typically be made of a steel having a low residual magnetic content.

The outer side surface of the magnetic sleeve 52 has different diameters and defines a rear area 54 which faces the duct 44' with a diameter which is equal to or slightly smaller than the inner diameter of the intermediate part 42 of the body 12 and defines a front adjacent area 56 facing the hole or outlet duct 36with a smaller diameter.

The areas 54 and 56 mentioned above having different diameters form a coupling shoulder 58 for the rear spring 20' and globally the first end of the magnetic sleeve 52 couples with the body 12 in the intermediate part 42 near the narrowing of the terminal part 44 which defines the inlet duct 44'. The axial sliding return of the piston 16 is obtained by means of known technical means, such as, e.g., the pair of coil springs 20 and 20' previously described (these springs, therefore, cooperate with the piston 16 itself).

The supply of the coil 14 is obtained, e.g., by means of a conventional pair of electrical connections, e.g. of the quick-coupling type as illustrated in Figure 1 with the reference number 62. The applicant has discovered, experimentally, that the motor pump of the present invention is highly efficient thanks to the presence of the magnetic sleeve 52 which, being aligned with the sliding axis of the piston 16 with one of its ends, is close to the piston and, therefore, at a shorter distance between the latter and one of the two possible magnetic sleeves 46, 46' when placed in the position reached by the piston 16 during the loading of the rear spring 20', generally near the terminal part 44 of the body 12.

The invention achieves different advantages.

First of all, the presence of noise-decreasing means, both in separate terms of the "passive" or "active/preventive" elements (and, obviously, in joined and simultaneous terms) allows to maintain rather heavy-duty working conditions of the motor pump, without, however, being negatively affected by wobbling in the piston stroke and, therefore, without generating noise, shocks or "mechanical impulse" phenomena that can also damage the internal components of the motor pump itself.

In any case, the presence of the noise-decreasing means does not compromise the performance increase due to the interaction between the magnetic sleeve 52 and the remaining magnetically active/sensitive components of the motor pump: this means that this improved motor pump is subjected only to an increase in the magnetic attraction force exerted on the piston 16 and to that exerted on the fluid which comes out from the delivery duct 22, but it is not affected (except in predetermined "undesired" moments, i.e. in those operating moments when the piston 16 has exceeded its maximum permissible stroke point and is therefore very close to a noisy impact with other components of the motor pump itself) by the slowing down/braking magnetic effects already mentioned in other parts of the present description.

Thanks to the presence of the magnetic sleeve 52 it is conveniently possible to reduce the number of wires of the coil 14, with considerable production savings. The motor pump manufactured according to the previous description does not imply any impediments or additional costs caused by the increased size of the coil and the related turns of wires, while the magnetic sleeve 52 can be easily obtained and installed at low cost (like the noise reduction/absorption/prevention means described so far and/or claimed below).

Although the present invention has been described with reference to a possible embodiment given as an illustrative and non-limiting example, many changes and variations can be made in the arrangement of the components by a person skilled in the art, according to the aforementioned description. It will therefore be understood that the present invention intends to include all the changes and variations in the arrangement of the components which fall within the scope of protection of the following claims.