Patent Description:
Ventilation apparatuses are known, for example used in association with burners for boilers, each of which comprises an electric motor and an impeller inserted in a spiral or volute shaped box, and attached to the shaft of the electric motor itself. Normally, the electric motor is mounted on the spiral shaped box or on its closing plate.

Usually a fluid, for example a mixture of air and gas coming from an external mixer, enters the spiral shaped box, for example coaxially to the axis of rotation of the impeller, and is conveyed by the latter outside the spiral shaped box, for example tangentially toward a burner.

In order to try to interrupt the transmission of the noise and vibrations generated by the rotation of the impeller made to rotate by a motor connected to it, it is known to use damping members, interposed between the electric motor and the spiral shaped box on which it is mounted.

Ventilation apparatuses are known, which use different solutions to attach the damping members to the electric motor and to the spiral shaped box. The damping members used are, for example, vibration dampers, usually made of rubber, or rubber-based materials, or materials having characteristics similar to those of rubber, such as the so-called "silent blocks", widely used commercially, which are connected to the spiral shaped box and to the electric motor by means of screws or bolts, which function as attachment members.

However, these ventilation devices have the disadvantage that they are bulky, since the threaded attachment members normally have such a length as to excessively increase the distance between the lower part of the electric motor and the spiral shaped box.

It is also known to use ventilation apparatuses that use a support plate raised above the spiral shaped box, in which the damping members are coupled with the support plate and with the external part of the electric motor, but are thus raised with respect to the spiral shaped box. Although this apparatus does allow to improve the damping of vibrations with respect to the solution described above, it still has the disadvantage of having an excessive overall size, since the raised plate keeps the motor too far distanced from the spiral shaped box.

Document <CIT> describes a ventilation apparatus in which the damping members are located resting on base elements associated with a support plate and connected to the base elements by means of screws.

<CIT> describes a vibration damping device for an electric motor, which has fastening elements and fastening seatings respectively associated with a motor support element and with a wall of a housing of the fan, disposed inclined with respect to them, with which respective damping members can be connected in the radial direction. This solution is complex in that it requires the correct alignment of the respective fastening elements and fastening seatings and, moreover, the inclined positioning of the damping members entails large overall sizes.

<CIT> describes a fan comprising a housing, a motor and a resilient sealing element disposed between them. The fan also comprises a member that functions as a bearing, which is attached to rest elements around the drive shaft to dampen the vibrations of the latter so as to avoid excessively compressing the resilient sealing element.

Document <CIT> describes a housing device for a motor of a ventilation apparatus in which the damping members are located resting on and connected to support elements provided on a frame, which is in turn connected by means of screws to a support plate that closes the housing of the motor. This solution is also bulky and requires an additional component, namely the frame, which entails an increase in the overall sizes.

One purpose of the present invention is to provide a ventilation apparatus which has a minimum bulk, while maintaining its characteristics of damping between the electric motor and the spiral shaped box, and its characteristic of silence.

Another purpose of the invention is to guarantee a correct seal between the fan and the motor in order to prevent possible gas leaks which could be dangerous in the event that the ventilation device is used in apparatuses for feeding combustible gas.

Another purpose of the present invention is to provide a ventilation apparatus which has a reduced number of components which are simple and fast to assemble.

In accordance with the above purposes, a ventilation apparatus according to the present invention comprises an electric motor, support means configured to support the electric motor and comprising a plate, and damping members interposed between the support means and the electric motor.

In accordance with the present invention, the ventilation apparatus also comprises at least first attachment elements made in a single body with the plate, protruding with respect to a flat portion of the latter, and configured to couple, in a snap-in or elastic interlocking manner, with the damping members in an axial direction.

According to the invention, the first attachment elements are conformed to be inserted into a lower hole of the damping members in such a way that a lower surface of the damping members is located resting on the flat portion.

In particular, according to some embodiments, the first attachment means are completely inserted inside the damping members.

In accordance with another aspect of the present invention, the ventilation apparatus also comprises an impeller connected, for example attached, to the shaft of the electric motor and mounted rotatable inside a spiral or volute shaped box, closed at its upper part by the plate.

In accordance with another aspect of the present invention, the first attachment elements are obtained by means of molding, pressing, or drawing of the plate.

In accordance with another aspect of the present invention, said plate comprises a continuous surface in which a single central hole is provided, through which the shaft of the electric motor passes. In this way, since a sealing packing is generally disposed around the shaft of the electric motor and no further holes or apertures are present on the plate, possible gas leaks through it are prevented, which could be dangerous in the case of applications to apparatuses for feeding combustible gases.

In accordance with another aspect of the present invention, each of the damping members comprises a tubular element of elastic material, for example substantially cylindrical, provided with at least the lower hole, which can preferably be axial. Furthermore, each of the first attachment elements comprises a central body, for example cylindrical, having substantially the same sizes as the lower hole, and an upper element with larger sizes than those of the central body, whereby each of the first attachment elements is substantially mushroom-shaped.

In particular, the first attachment elements are mushroom-shaped, with the upper part turned upside down and recessed deriving from a pressing and/or drawing process.

In accordance with another aspect of the present invention, in which each of the damping members comprises a tubular element of elastic material, provided with at least one lower hole, preferably axial, each of the first attachment elements comprises a central body, having substantially the same sizes as the lower hole, and an axial peg provided with an annular groove in which an elastic stop ring is able to be inserted.

In accordance with another aspect of the present invention, in which the shaft has its own longitudinal axis, each of the first attachment elements has a first central axis substantially parallel to the longitudinal axis.

In accordance with one aspect of the present invention, each of the first attachment elements has a first central axis inclined by a first angle with respect to the plate.

In accordance with another aspect of the present invention, the plate, in a central zone thereof, is bent circumferentially toward the impeller, in order to define a recess in which a lower part of the electric motor is housed.

In accordance with another aspect of the present invention, the ventilation apparatus also comprises second attachment elements integral with the electric motor and configured to couple, in a snap-in or interlocking manner, with the damping members on the other side with respect to the first attachment elements.

Thanks to the fact that the damping elements can couple in a snap-in manner on both sides with the first attachment elements and the second attachment elements, respectively, it is possible to considerably reduce the overall sizes, since the distance between the second attachment elements integral with the motor and the first attachment elements integral with the plate is substantially defined only by the axial length of the damping members.

In accordance with another aspect of the present invention, each of the damping members is provided with at least one upper hole, preferably axial, and each of the second attachment elements is configured to be inserted into one of the upper holes.

According to one aspect of the invention, each of the second attachment elements comprises a substantially cylindrical body, having substantially the same diameter as the upper hole of the damping member, and a lower part, for example with a substantially truncated conical or cylindrical shape, having, in the zone in contact with the body, a transverse size greater than that of the upper hole, so that the second attachment element has substantially the shape of a mushroom with the head facing in the opposite direction with respect to the first attachment elements.

In accordance with another aspect of the present invention, each of the damping members is of the bent type and comprises a lower part coaxial to the first central axis and an upper part coaxial to a second axis which is inclined by a second angle with respect to the first central axis.

We must clarify that in the present description and in the claims the terms upper, lower and low, with their declinations, have the sole function of better illustrating the present invention with reference to the drawings and must not be in any way used to limit the scope of the invention itself, or the field of protection defined by the attached claims.

Furthermore, the people of skill in the art will recognize that certain sizes or characteristics in the drawings may have been enlarged, deformed, or shown in an unconventional or non-proportional way in order to provide a version of the present invention that is easier to understand. When sizes and/or values are specified in the following description, the sizes and/or values are provided for illustrative purposes only and must not be construed as limiting the scope of protection of the present invention, unless such sizes and/or values are present in the attached claims.

With reference to <FIG>, a ventilation apparatus <NUM> according to the present invention is configured to be used, preferably but not exclusively, in association with burners for boilers, of a known type and not shown in the drawings.

In accordance with a first embodiment, shown in figs. from <NUM> to <NUM>, the ventilation apparatus <NUM> comprises an electric motor <NUM> (<FIG> and <FIG>), which can be of any known type whatsoever, or which will be developed in the future, for example a direct current, alternating current, or brushless motor, and support means <NUM> configured to support the electric motor <NUM>.

The support means <NUM> comprise in particular a plate <NUM>, preferably metallic, or in any case of a sufficiently strong and rigid material, in a way that will be described in detail below.

The electric motor <NUM> has a shaft <NUM> rotatable around its own longitudinal axis X (<FIG>), and mounted on the upper part of the plate <NUM>.

The plate <NUM> is substantially perpendicular to the longitudinal axis X and is provided with a central hole <NUM> coaxial to the latter, through which the shaft <NUM> passes with clearance. An impeller <NUM>, of a known type and provided with blades <NUM>, is integrally attached to the lower end of the shaft <NUM> and is configured to move a fluid, for example a mixture of air and gas, for example in order to feed a burner for a boiler.

The impeller <NUM> is mounted rotatable, with clearance, inside a spiral or volute shaped box <NUM>, closed at its upper part by the plate <NUM>.

Preferably, the plate <NUM> has a continuous surface, substantially without holes or apertures except for the single central hole <NUM>, at least in correspondence with the portion of the plate <NUM> that cooperates with the motor <NUM> and/or the impeller <NUM>, so as to prevent possible gas leaks.

Alternative embodiments, not shown in the drawings, can provide that the spiral shaped box <NUM> is formed by two half-shells coupled together, and that the plate <NUM> constitutes the upper part of the upper half-shell.

The spiral shaped box <NUM> is provided with a lower suction aperture <NUM>, coaxial to the longitudinal axis X, and with a lateral delivery aperture <NUM>. Therefore, when the impeller <NUM> is made to rotate by the electric motor <NUM>, the fluid coming, for example, from a mixer of a known type and not shown in the drawings, enters the spiral shaped box <NUM> from below and exits radially from the latter in order to be conveyed toward the burner for a boiler.

A protective cover <NUM>, for example made of insulating material, is positioned around the electric motor <NUM>.

The connection between the electric motor <NUM> and the plate <NUM> is made by means of a plurality of damping members <NUM>, which in the example provided here are three, angularly distanced from each other with respect to the longitudinal axis X.

Each damping member <NUM> comprises a tubular element <NUM>, for example substantially cylindrical, made of elastic material, such as for example rubber, or of rubber-based materials, or materials having characteristics similar to those of rubber, and having the function of interrupting the transmission of vibrations and noise produced by the rotation of the electric motor <NUM> and of the impeller <NUM>. The sizes of the damping members <NUM> are suitably chosen on the basis of the sizes and/or other characteristics of the electric motor <NUM>.

Each damping member <NUM> is provided with at least one lower axial hole <NUM>.

Preferably, each damping member <NUM> is also provided with an upper axial hole <NUM>.

The lower <NUM> and/or upper <NUM> hole/s are coaxial to a central axis Y, which can be either parallel to the longitudinal axis X (<FIG>, <FIG>, <FIG>, <FIG>), or inclined with respect to it (<FIG>), as will be described in detail below.

Each damping member <NUM> could also be of the bent type, as in the third embodiment shown in <FIG> and described in detail below.

The damping members <NUM> are attached to the plate <NUM> by means of first attachment elements <NUM> (<FIG>), which are advantageously configured to create a snap-in or elastic interlocking coupling between the damping members <NUM> and the plate <NUM>.

In particular, in accordance with the first embodiment, the first attachment elements <NUM> are each formed by a cylindrical body <NUM>, having a diameter substantially equal to, or slightly greater than, the diameter of the lower axial hole <NUM> of the damping member <NUM>, and by an upper part <NUM>, substantially in the shape of a disc, with a diameter greater than that of the cylindrical body <NUM>, so that they substantially have the shape of a mushroom.

The sizes and the ratios between the first attachment elements <NUM> and the damping members <NUM> are such as to allow their coupling and their integrality by means of an elastic deformation of the latter, thus obtaining a snap-in or elastic interlocking coupling.

The plate <NUM> with integrated first attachment elements <NUM> is obtained by means of any known method or working whatsoever, for example starting from any suitable material, such as sheet metal, aluminum, or suitable plastic materials, for example by means of molding, or pressing, whereby the first attachment elements <NUM> are in a single body with the plate <NUM>.

Preferably, the first attachment elements <NUM> can be made by drawing or pressing the plate <NUM>, in such a way that they are protruding with respect to a flat portion <NUM> of the latter.

In accordance with one aspect of the invention, the first attachment elements <NUM> are conformed to be inserted into the lower hole <NUM> of the damping members <NUM> in such a way that a lower surface <NUM> of the damping members <NUM> is located resting on the flat portion <NUM>.

In accordance with another characteristic of the present invention, which can also be considered autonomous with respect to the others, the connection between the damping members <NUM> and the electric motor <NUM> can also be made by means of a snap-in or elastic interlocking coupling. For this purpose, the external part of the electric motor <NUM> is provided with radial fins <NUM>, three in the example provided here, each configured to couple with a corresponding damping member <NUM>.

A second attachment element <NUM> (<FIG>) is integral with the lower part of each radial fin <NUM> and comprises a body <NUM>, for example substantially cylindrical, having substantially the same diameter as the upper axial hole <NUM> of the damping member <NUM>, and a lower part <NUM>, for example with a substantially truncated conical or cylindrical shape, having, in the zone in contact with the body <NUM>, a diameter greater than that of the upper axial hole <NUM>, so that the second attachment element <NUM> has substantially the shape of a mushroom with the head facing downward.

The sizes and the ratios between the second attachment elements <NUM> and the damping members <NUM> are also such as to allow their coupling and their integrality by means of an elastic deformation of the latter, thus precisely obtaining a snap-in or elastic interlocking coupling.

Therefore, by using snap-in or elastic interlocking couplings between the damping members <NUM> and the plate <NUM> on one side and/or the electric motor <NUM> on the other side, that is, without the use of screwable attachment elements, such as for example screws or bolts, it is possible to reduce the space between the electric motor <NUM> and the plate <NUM>, that is, between the electric motor <NUM> and the impeller <NUM>.

In order to reduce the space further, in accordance with a second embodiment of the present invention, shown schematically in <FIG>, the first attachment elements <NUM> and therefore also the central axis Y of the damping members <NUM> are inclined by an angle α with respect to the plate <NUM>.

The angle α is chosen as a function of the sizes and/or other characteristics of the electric motor <NUM>, such as for example its weight, and it is comprised preferably between <NUM>° and <NUM>°.

This second embodiment, in addition to reducing the overall sizes, improves the stability of the electric motor <NUM> with respect to the plate <NUM>, and better counteracts any radial thrusts of the electric motor <NUM>.

In accordance with a third embodiment, shown schematically in <FIG>, the second attachment elements <NUM> have an inclined shape and comprise a lower part coaxial to the central axis Y and an upper part coaxial to a second axis Z, which is inclined by a second angle γ with respect to the central axis Y.

The second angle γ is also chosen as a function of the sizes and/or other characteristics of the electric motor <NUM>, such as for example its weight, and it is comprised preferably between <NUM>° and <NUM>°, so that with the third embodiment it is possible to obtain advantages similar to those obtained with the second embodiment.

In accordance with a fourth embodiment, shown schematically in <FIG>, in place of the upper part <NUM> each first attachment element <NUM> comprises an axial peg <NUM> provided with an annular groove <NUM> in which a stop ring <NUM> of the elastic type is inserted, possibly in a removable way. The latter can be, for example, a Seeger ring or a Benzing ring, both known to the people of skill in the art.

The stop rings <NUM> also allow to create a snap-in or elastic interlocking coupling between the plate <NUM> and the damping members <NUM>.

In accordance with a fifth embodiment, shown schematically in <FIG>, the plate <NUM>, in its central zone, that is, where the central hole <NUM> is made, is bent toward the impeller <NUM> and follows the upper profile of the blades <NUM>.

In this way, the plate <NUM> comprises a recess <NUM>, in the shape of a funnel, in which a lower part <NUM> of the electric motor <NUM> is advantageously housed. This allows to further reduce the distance between the electric motor <NUM> and the impeller <NUM>, so that a consequent reduction in the overall size of the ventilation apparatus <NUM> is achieved.

Advantageously, the ventilation apparatus <NUM> described heretofore allows to place the electric motor <NUM> in a position closer to the plate <NUM> and therefore to the impeller <NUM>, compared to the solutions present in the state of the art, allowing to reduce its overall size.

Advantageously, moreover, the ventilation apparatus <NUM> described heretofore, thanks to the snap-in or elastic interlocking couplings between the attachment elements <NUM> and/or <NUM>, and to the damping members <NUM>, has excellent sealing, vibration damping and noise reduction characteristics.

Advantageously, moreover, the attachment elements <NUM> and <NUM> are distanced and are connected to each other only by means of the damping members <NUM>, so that, since they are never in direct contact with each other, they do not transmit to the spiral shaped box <NUM> the vibrations and noise generated by the rotation of the rotor of the electric motor <NUM> and of the impeller <NUM> connected thereto.

It is clear that modifications and/or additions of parts may be made to the ventilation apparatus <NUM> as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of ventilation apparatus, all coming within the scope of the present invention.

Claim 1:
Ventilation apparatus (<NUM>), comprising an electric motor (<NUM>), support means (<NUM>) configured to support said electric motor (<NUM>) and comprising a plate (<NUM>), and damping members (<NUM>) interposed between said support means (<NUM>) and said electric motor (<NUM>), wherein said ventilation apparatus (<NUM>) also comprises at least first attachment elements (<NUM>) made in a single body with said plate (<NUM>), protruding with respect to a flat portion (<NUM>) of the latter, characterized in that said first attachment elements (<NUM>) are configured to couple, in a snap-in or elastic interlocking manner, with said damping members (<NUM>) in an axial direction, wherein said first attachment elements (<NUM>) are conformed to be inserted into a lower hole (<NUM>) of said damping members (<NUM>) in such a way that a lower surface (<NUM>) of said damping members (<NUM>) is located resting on said flat portion (<NUM>).