CN110998091A

CN110998091A - Hydraulic and electromagnetic floating piston electric pump

Info

Publication number: CN110998091A
Application number: CN201880050874.4A
Authority: CN
Inventors: 罗伯托·帕尔米耶里; 米凯莱·贝尼尼
Original assignee: Simi Co Ltd
Current assignee: Simi Co Ltd
Priority date: 2017-06-05
Filing date: 2018-05-22
Publication date: 2020-04-10
Anticipated expiration: 2038-05-22
Also published as: IT201700060837A1; EP3635253A1; CN110998091B; EP3635253B1; WO2018224903A1

Abstract

A floating piston electric pump comprising a body defined by a coil, inlet and outlet conduits, a sliding piston and a magnetic sleeve coaxial with the sliding axis of the piston; the magnetic sleeve interacts with a pair of magnetic bearings to increase the magnetic attraction force exerted on the piston, and there is also a noise reduction device operatively activated and located between the magnetic sleeve, the piston and the body.

Description

Hydraulic and electromagnetic floating piston electric pump

The present invention relates to a hydraulic, electromagnetic floating piston electric pump (motor pump), and more particularly to a hydraulic, electromagnetic floating piston electric pump adapted to move a fluid such as water.

Electric pumps of this type are applied to various devices, such as irons, electric coffee machines, irrigation systems, and also in the automation industry: electromagnetic hydraulic electric pumps with floating pistons are known, for example, from EP- ｃA-1205663, US- ｃA-4749343, EP- ｃA-1001167, and EP- ｃA-0288216 (and more specifically EP- ｃA-1205663 discloses ｃA hydraulic, electromagnetic floating piston electric pump having the features of the preamble of claim 1).

The operation of this type of electric pump is based on coils cooperating with a pair of magnetic bearings: the coil is electrically driven and causes alternating motion axial movement of the floating piston or causes alternating motion axial movement of the piston.

The same applicant has already made available in the prior art a particular type of floating piston electric pump, in which there is also a magnetic sleeve which functionally cooperates with the remaining "magnetically active" parts of the electric pump itself to improve the interaction of the magnetic field, thus improving the motion/power of the floating piston itself and thus increasing the performance of the electric pump at least in terms of the level of higher pressures that can be achieved, while maintaining a very low overall load (and also a low production cost) of the electric pump itself.

However, the known electric pumps disclosed so far are in any case subject to drawbacks related to noise: in fact, under certain operating conditions, the floating piston, during its stroke, is more or less in abutment in a controlled manner against other parts of the electric pump, thus generating sound waves which can also have a high sound intensity at high frequencies (and therefore in a particularly annoying, perceptible manner of tone) or in any case.

The object of the present invention is therefore to overcome the drawbacks described above, and more particularly it relates to an embodiment of a hydraulic, electromagnetic floating piston electric pump in which the noise level generated during normal operation (but also during operating moments in which the stroke of the floating piston may be "abnormal") is significantly reduced both in terms of volume and acoustic characteristics (frequency, duration and possible resonance phenomena).

It is a further object of the present invention to provide an electric pump of the type: the electric pump guarantees a high level of resistance and reliability over time, is easy to manufacture and can be made starting from small modifications (both of the plant and of the production line) with respect to other types of electric pumps already available.

These and other objects are achieved, according to the present invention, by an electric pump according to the present invention, which is hereinafter exemplified-and not limited for this reason-in the form of its possible embodiments illustrated in the accompanying drawings, wherein the drawings themselves represent:

fig. 1 is a schematic exploded view of the applicant's electric pump, already part of the prior art, and which is the basis of the technical improvements introduced in the present invention;

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

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

Referring to the drawings, an electric pump of the present invention is generally indicated by reference numeral 10 and basically comprises the following structural components:

a body 12, on an outer portion thereof, said body being partially delimited by a coil 14;

an inlet duct 44 'and an outlet duct 36 opposite to the inlet duct 44', the inlet and outlet ducts being obtained in the main body 12;

a piston 16 slidably arranged within the body 12; and

a magnetic sleeve 52 having a first end located inside the body 12 and, more precisely, in the portion of the body facing the inlet duct 44'.

More in detail, the first end of the above-mentioned magnetic sleeve 52 is arranged coaxially to the sliding axis of the piston 16 so as to be coupled with the body 12 in the intermediate portion 42 of the body (i.e. in the vicinity of the end portion 44 defining the inlet duct 44'): also, if desired, the magnetic sleeve 52 may functionally interact with the body 12 to increase the overall magnetic field, and thus the magnetic attraction force applied to the piston 16.

In further detail and with reference to fig. 1, it can be seen that the prior art electric pump presented herein further comprises a pair of magnetic bearings 46, 46': these magnetic bearings are spaced apart from each other and are provided between the body 12 and the coil 14, and at the same time the pair of magnetic bearings are arranged coaxially with the sliding axis 16a of the piston 16, functionally interact with the piston 16 and/or with the magnetic sleeve 52 to increase the magnetic field and, consequently, the magnetic attraction force exerted on the piston 16.

On the other hand, fig. 2 and 3 show an electric pump according to the invention, in which the magnetic bearings 46, 46' are not visible: in any case, these two structural components (and in the same way, in turn, the coil 14 is not shown in fig. 2 and 3, but the coil is implicitly present in the inventive structure, and in any case, structurally and functionally able to position/couple the electric pump at least with the body 12, and/or with the piston 16, according to methods known to those skilled in the art when designing and implementing the oscillating cursor) can be considered as optional structural features of the invention, and if present, they are positioned with respect to the body 12 and/or with respect to the sliding axis 16a of the piston 16, in order to increase, in the most suitable way, the magnetic interaction with the piston 16 and therefore the flow and/or pressure performance of the electric pump 10.

In more 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 fig. 1, also in the manner of an electric pump with a geometric/structural arrangement of the remaining components according to the invention, and more precisely in the manner of the arrangement of fig. 2 and/or 3 (or the coil and the pair of magnetic bearings can be implemented according to structural and functional coupling methods, which are well known to the skilled person when designing and implementing oscillating cursor electric pumps).

Conveniently, in embodiments of the invention where magnetic bearings 46, 46 'are present, the noise reduction device will also be operatively active between the magnetic bearings 46, 46', between the magnetic sleeve 52, and between the pistons 16 (and, of course, between the coils 14).

Advantageously, the electric pump 10 according to the invention also comprises noise reduction means operatively active and located between the magnetic sleeve 52, the piston 16 and the body 12 (and optionally, also operatively active, if present, between the above-mentioned structural elements and the magnetic bearings 46, 46'): such noise reduction means are adapted to prevent collisions or impacts of the piston 16 on other parts of the electric pump 10 or, in the event of such collisions or impacts despite the presence of "preventive" technical measures, are adapted to absorb and include-at least partially-acoustic energy generated by such collisions or impacts.

From a structural point of view, the noise reducing device described above comprises at least one passive movement and/or sound absorbing element 100, which is positioned at the end of the stroke of the piston 16 and is adapted to withstand impacts by the piston 16 itself: the passive moving and/or sound absorbing element 100 comprises a body, preferably an annular body, made of polymeric material and more preferably of material having superelastic properties (therefore, the passive moving and/or sound absorbing element may conveniently be made of a material based on natural or synthetic rubber, or in any case, of a material capable of absorbing or dissipating the energy of the impact/collision of the piston 16, partially or totally suppressing the sound waves coming from these phenomena).

In other words, it can be seen that the passive movement and/or sound absorbing element 100 is interposed between the piston 16 and one or more of the other structural components of the electric pump 10, at least in relation to the "end of stroke" arrival time of the movement of the piston 16 itself.

Although the passive motion and/or sound absorbing element 100 is activated in its function only when the stroke of the piston 16 reaches a geometrically unwanted point, there may also be noise reducing means adapted to be "active/preventing" in the present invention: these means comprise at least one active prevention assembly 200 for impacts and/or collisions, which results in activation near at least one end of the piston 16 to prevent collisions or the piston coming into contact with one or more of the following components:

-a main body 12; and/or

-a magnetic sleeve 52; and/or

Magnetic bearings 46, 46' (if present).

From a functional/operational point of view, the above-described active prevention assembly 200 is adapted to exploit specific variations (or variants) of the direction (and, if required, also scalar) of the vector produced by the magnetic interaction 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': this magnetic interaction, as described above, varies in vector direction, which occurs in particular when the piston 16 crosses a certain threshold point of its travel, defining a new equilibrium of forces in which the attractive magnetic component along the sliding axis 16a decreases, and in which, as a result, the travel of the piston 16 is braked.

Due to the appropriate location and dimensions of the active prevention assembly 200, the end of travel of the piston 16 can be controlled, at least near the maximum geometric end of travel established by the dimensions of the body 12, so as to stop and reverse the movement of the piston 16 itself before it hits a structural component (on which the piston has hit, thus "producing sound").

In more 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 the ends of the piston, and a second interaction portion 200b located in the vicinity of the second interaction portion 200a, typically at the end of the stroke of the piston 16, but which is in turn formed in the magnetic sleeve 52 and/or, if present, in the magnetic bearings 46, 46' and/or in the body 12.

From a functional point of view, and more precisely from an interaction point of view, the first and second interacting

portions

200a, 200b interact to define a vector variation of the magnetic interaction force suitable for braking and/or decelerating the piston 16.

According to the illustrated exemplary embodiment, the first and second interacting

portions

200a, 200b may conveniently be of complementary shape and, for example, geometrically interpenetrate each other along the sliding axis 16 a: this complementary geometry allows a mutual interpenetration without contact when the piston 16 is moving, so as to be able to expose the piston 16 itself to magnetic field lines suitable for "changing in deceleration/braking direction", but without mechanical contact and therefore without noise.

Still referring to the figures, it can be seen how, for example, the first interaction portion 200a includes, for example, a cylindrical or annular protrusion disposed at one end of the piston 16 (or, conversely, a cavity disposed at one end of the piston, not shown), while the second interaction portion complementarily includes a cylindrical or annular cavity disposed on the magnetic sleeve 52 (or, conversely, a protrusion disposed on the magnetic sleeve) and the cavity or protrusion of the second interaction portion may circumscribe or be inscribed within the protrusion or cavity of the first interaction portion 200 a.

As already described previously, the electric pump 10 comprises, in its basic structure, an inlet duct 44 ', an opposite outlet duct 36, the body 12 (defined in part by the coil 14 on the outside thereof), optionally a pair of opposite magnetic bearings 46, 46 ' (spaced apart from each other and disposed between the body 12 and the coil 14), and the piston 16 (disposed inside the body 12 and flowing therein, elastically supported by the front 20 and rear 20 ' helical springs). In front of the piston 16, in the portion facing the transfer duct, there are normally provided a sealing valve and an elastic band of the piston 16: the elastic band and the sealing valve cooperate with a packing and a support bearing elastically stretched by other coil springs.

The above-mentioned helical spring and at least part of the gasket are housed in a seat of the transfer duct of a diameter suitable for housing the assembly consisting of the gasket and the helical spring (normally, this diameter is greater than the diameter of the outlet duct or hole of the transfer duct).

A locking ring 38 with internal thread engages with a suitable counter-shaped part (which may also be threaded, depending on the more or less "reversible" coupling twist), which is external to the body 12 and is arranged on the duct 22 according to the known prior art.

For its part, the tubular body 12 comprises a front portion 40, of larger diameter and facing the outlet duct 36, an adjacent intermediate portion 42, of smaller diameter than the front portion 40 and delimiting the sliding axis chamber of the piston 16, and an end portion 44, of much smaller diameter than the intermediate portion 42 and defining the inlet duct 44'.

The opposed magnetic bearings 46 and 46' may be conveniently spaced from each other by the use of spacer elements and, if desired, adapted to be mounted on the outside surface of the intermediate portion 42 of the body 12: meanwhile, the coil 14 is in turn adapted to be on the body 12 such that the coil may include any magnetic bearing 46, 46'.

The coil 14 is stabilized by known technical means, for example consisting of an elastic ring in some shape coupled to a face of the coil and a shoulder (visible and indicated by the reference 50 in fig. 1) provided on the body 12 (for example, such coupling being between the front portion 40 and the intermediate portion 42, with a smaller diameter coupled to the opposite face).

Within the body 12, more precisely in the central lower portion facing the inlet duct 44', there is housed a magnetic sleeve 52, which can be generally made of steel with a low residual magnetic content.

The outside surfaces of the magnetic sleeves 52 have different diameters and define a rear region 54 facing the conduit 44', the diameter of which is equal to or slightly less than the inside diameter of the intermediate portion 42 of the body 12, and a front region 56 facing the vicinity of the hole or outlet conduit 36 having the smaller diameter.

The

aforementioned areas

54 and 56 of different diameter form a coupling shoulder 58 for the rear spring 20 'and integrally couple the first end of the magnetic sleeve 52 with the body 12 in the intermediate portion 42 near the narrowed end portion 44, which defines the inlet duct 44'. The axial sliding return of the piston 16 is obtained by known technical means, such as the pair of helical springs 20 and 20' previously mentioned (these springs therefore cooperate with the piston 16 itself).

The supply of the coil 14 is obtained, for example, by means of a pair of electric connectors of the usual type, for example of the quick coupling type, as indicated in fig. 1 with the reference number 62.

The applicant has experimentally found that the electric pump of the invention is efficient thanks to the presence of a magnetic sleeve 52, one of the ends of which is aligned with the sliding axis of the piston 16, which is close to the piston and therefore during the loading of the rear spring 20 ', generally near the terminal portion 44 of the body 12, which is located at a short distance between the piston and the two possible magnetic sleeves 46, 46' when it is set in the position reached by the piston 16.

The invention has the following different advantages:

firstly, the presence of the noise reducing means, both in terms of "passive" or "active/preventing" elements (and notably in terms of coupling and simultaneously), respectively, allows to maintain the relatively heavy working conditions of the electric pump, without being negatively affected by the oscillations in the piston stroke, and therefore without generating noise, shocks or "mechanical impulse" phenomena, which could also damage the internal components of the electric pump itself.

In any case, the presence of the noise reducing means does not imply an increased performance compromise due to the interaction between the magnetic sleeve 52 and the remaining magnetically active/sensitive components of the electric pump: this means that the improved electric pump only suffers from an increase in the magnetic attraction force exerted on the piston 16 and on the fluid flowing out of the delivery duct 22, but it is not affected by the decelerating/braking magnetic effect mentioned in the rest of the description (unless at predetermined "unnecessary" moments, i.e. moments in time when the piston 16 has a noise exceeding its maximum permitted stroke and therefore very close to the impact of other components of the electric pump itself).

Due to the presence of the magnetic sleeve 52, it is possible to advantageously reduce the number of wires of the coil 14, with a significant saving in production.

An electric pump made in accordance with the present description does not imply any impediments or other costs resulting from increased coil size and associated wire variation, while the magnetic sleeve 52 may be readily obtained and installed at low cost (e.g., the noise reduction/absorption/prevention devices described and/or claimed).

Although the present invention has been described with reference to possible embodiments, given as illustrative and non-limiting examples, numerous variations and modifications of the arrangement of parts may be made by those skilled in the art in light of the above description. It is, therefore, to be understood that the invention is intended to cover all such changes and modifications as fall within the scope of the appended claims.

Claims

1. A hydraulic, electromagnetic, floating piston electric pump (10) comprising:

-a body (12) external to which it is partially delimited by a coil (14);

-an inlet duct (44 ') and an outlet duct (36) opposite said inlet duct (44'), said inlet duct and said outlet duct being obtained in said main body (12);

-a piston (16) slidably arranged within the body (12); and

-a magnetic sleeve (52) having a first end disposed inside the container body (12), a portion of said body facing said inlet duct (44 '), and a first end of said magnetic sleeve being arranged coaxially to the sliding axis of said piston (16), said first end of said magnetic sleeve (52) being coupled to the body (12) of the container in an intermediate portion (42) of said body adjacent to an end portion (44) of said body (12) defining said inlet duct (44'), said magnetic sleeve (52) interacting at least with said coil (14) to increase the magnetic field and thus the magnetic attraction force applied to said piston (16),

characterized in that it further comprises noise reduction means operatively activated and located between at least said magnetic sleeve (52), said piston (16) and said body (12).

2. An electric pump according to claim 1, wherein there is also a pair of opposed magnetic bearings (46, 46 ') spaced apart, between the body (12) and the coil (14), the pair of opposed magnetic bearings (46, 46 ') being arranged coaxially with the 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 thus the magnetic attraction force exerted on the piston (16), the noise reduction means being operatively activated also between the magnetic bearings (46, 46 '), between the magnetic sleeves (52) and between the pistons (16).

3. An electric pump according to claim 1 or 2, wherein the noise reducing means comprise at least one passive movement and/or sound absorbing element (100) provided at the end of the stroke of the piston (16) and adapted to withstand impacts caused by the piston (16) itself.

4. An electric pump according to claim 3, wherein said at least one passive moving and/or sound absorbing element (100) comprises a body, preferably an annular body, made of a polymeric material and more preferably a material having superelastic properties.

5. An electric pump according to any of the preceding claims, wherein the noise reduction arrangement comprises at least one active prevention component (200) to actively prevent shocks and/or collisions, the active prevention assembly is operatively activated near at least one end of the piston (16) to inhibit material from impacting or contacting the body (12) and/or the magnetic sleeve (52) and/or the magnetic bearing (46, 46'), the active prevention assembly (200) is adapted to slow and/or brake the piston (16) itself with respect to at least one threshold point of piston travel along the sliding axis (16a) by means of a vector variation of the magnetic interaction 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 bearing (46, 46').

6. The electric 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;

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

the first and second interacting portions (200a, 200b) interact to define a change in interaction of a magnetic vector adapted to brake and/or decelerate the piston (16).

7. The electric pump according to claim 6, wherein the first and second interacting portions (200a, 200b) are of complementary shape and preferably geometrically interpenetrate each other along the sliding axis (16 a).

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

9. An electric pump according to any of the preceding claims, wherein the piston (16) is supported by a front helical spring (20) and a rear helical spring (20') provided within the body (12).

10. The electric pump according to any 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 portion (42) having a diameter smaller than the diameter of the front portion (40) and delimiting a sliding chamber of the piston (16); and

-a terminal portion (44) having a diameter smaller than the diameter of the intermediate portion (42), the terminal portion (44) defining the inlet duct (44').

11. The electric pump according to claim 9 or 10, wherein the outer side surface of the magnetic sleeve (52) comprises:

-a rear region (54) facing the inlet duct (44') and having a diameter equal to or slightly smaller than the inner diameter of the intermediate portion (42) of the body (12); and

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

12. Electric pump according to any one of the preceding claims, wherein the first end of the magnetic sleeve (52) is coupled with the body (12) in the intermediate portion (42) adjacent to the narrowed end portion (44) defining the inlet duct (44 '), the distance between the opposite end of the magnetic sleeve (52) and the piston (16) being smaller than the distance between the piston and one or the other of the magnetic bearings (46, 46 ') when set in the position reached by the piston (16) during the loading step of the rear spring (20 ').

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