RU2607116C2 - Centrifugal fan - Google Patents

Abstract

FIELD: ventilation.

SUBSTANCE: invention relates to centrifugal fan (1) containing the impeller (4), drive motor (3) of the impeller (4), housing (2) containing central part (17) to accommodate engine (3) and the impeller (4), and tangential discharge channel (18) communicating with said central part (17). Housing (2) has an inlet hole (15) in the central part (17) and outlet hole (16) in the tangential discharge channel (18), as well as system (4, 14, 28, 29) of engine cooling (3) containing the impeller (4), vent channel (31) functioning between tangential discharge channel (18) and central part (17), ring element (28) made integral with working wheel (4) and passes in axial direction from the impeller (4) around the engine (3), and multiple radial blades of the engine to create tangential cooling component, that is combined with cooling air flow, creating as a result of helical vortex RF around engine (3).

EFFECT: invention is aimed at effective cooling of the engine.

9 cl, 10 dwg

Description

Technical field

The invention relates to a centrifugal fan and, in particular, to a centrifugal fan containing a cooling system of a fan motor.

State of the art

In the automotive industry (for passenger, freight transport and for other similar applications), the use of centrifugal fans driven by open type DC motors is widespread.

Such fans traditionally have cooling systems for drive motors associated with fans, which are based on forced circulation of cooling air.

In FIG. 1 is a schematic partial cross-sectional view of a centrifugal fan known in the art.

A fan of this type comprises an outer casing 100 in the form of a spiral formed by a central part 101 and an exhaust duct 102 in communication with the central part 101.

The housing 100 has an inlet 103 made in the Central part 101, and an outlet 104 made at the end of the channel 102.

The engine 105, as a rule, of the "open" type has ventilation holes 105a and is mounted inside a spiral to drive the impeller 106 of the centrifugal fan, which is mounted to rotate around its axis R and is designed to suck in air at the inlet 103 and move the pumped air into channel 102 of spiral 2.

The impeller 106, driven in rotational motion, creates a pressure differential between the inlet 103 and the outlet 104 to form an air flow F along the channel 102. In general, this means that there is high pressure at the outlet of the fan, or outside the fan, and at the inlet to the fan, or inside the fan, there is a negative pressure (compared to the outlet pressure).

The cooling system of the engine 105 comprises a recirculation channel 107 having an inlet in communication with the channel 102 and an outlet in communication with the central part 101. The channel 107 traps compressed air at the outlet of the housing 100 to form an RF flow of cooling air expelled by the overpressure generated by the impeller 106, to the central part 101 at the rear of the engine 105. Thus, the RF cooling air stream passes through the ventilation holes 105a of the engine 105, removing heat directly from the motor windings I’m 105, and again falls into the inner part of the impeller 106, from where it re-enters the channel 102.

In the main markets for such fans, there is a need for an improved technical solution that allows the use of an electronic motor drive that is integrated into the motor, regardless of whether the motor is a brushless motor or a DC motor, and also allows to increase the service life and reliability of the motor in severe operating conditions.

The main obstacle to the implementation of such solutions is the relatively low performance of engine cooling systems known from the prior art, which are not able to provide optimal operating conditions for operating fans.

It is believed, for example, that when integrating the drive electronics into the motor, the maximum operating temperature should be below the temperature of the windings by up to 50 ° C. As a result, it is important that the engine cooling system can dissipate a significant amount of heat so as not to exceed the extreme operating conditions.

It should be noted that both the service life of the product and the ability to work in harsh operating conditions are closely related to the ability to ensure proper and efficient cooling of the engine and the associated electronics unit.

Disclosure of invention

In this regard, the main technical task of the present invention is to provide a centrifugal fan, devoid of the above disadvantages.

One of the objectives of the present invention is to provide a centrifugal fan equipped with a highly efficient cooling system.

Another objective of the present invention is to provide a fan equipped with a cooling system capable of removing a significant amount of heat from the engine driving the impeller, including in the case of, for example, a closed motor in which the components to be cooled cannot be under the direct influence of the pressure flow of cooling air.

The specified main technical problem and other mentioned problems are essentially solved thanks to the centrifugal fan disclosed in the independent claim 1.

Brief Description of the Drawings

Other features and advantages of the present invention will become more apparent from the following non-limiting description of a preferred embodiment of a centrifugal fan with reference to the accompanying drawings, which depict the following.

In FIG. 1 is a schematic sectional view of a centrifugal fan known in the art.

In FIG. 2 is a schematic cross-sectional view of a centrifugal fan according to a first embodiment of the present invention.

In FIG. 3 is a plan view of a centrifugal fan according to a second embodiment of the present invention.

In FIG. 4 is a schematic cross-sectional view of the fan along line IV-IV of FIG. 3.

In FIG. 5, the fan part of FIG. 4 is shown on a larger scale for convenience.

In FIG. 6 is a top view of the fan of FIG. 3, while in the drawing some elements are missing to better illustrate the remaining parts.

In FIG. 7 shows a first perspective view of a first embodiment of an impeller of a centrifugal fan according to the invention.

In FIG. 8 is a second perspective view of the impeller of FIG. 7.

In FIG. 9 is a partial schematic cross-sectional view of a part of a fan according to a third embodiment of the present invention.

In FIG. 10 is a schematic perspective view showing an enlarged fragment of the fan impeller of FIG. 9.

The implementation of the invention

In the accompanying drawings, in particular in FIG. 2, reference numeral 1 indicates the proposed centrifugal fan.

The fan 1 has an axis of rotation R and comprises a housing, either a cochlea or a spiral, 2, an electric motor 3 of preferably a closed or "sealed" type, having a corresponding shaft 3a located in the housing 2, which serves as a support for it, and the impeller 4, shown in particular in FIG. 7 and 8 and driven by the engine 3.

The impeller 4 is mounted to rotate around the axis R and contains many blades 5 of a centrifugal fan having a main length along the axis R, and the first and second support rings 6, 7, between which the blades 5.

The impeller 4 has a first inlet 8 formed by an opening bounded by a support ring 7, the axis of which coincides with the R axis, and a tangential exit 9, which is actually formed by the gaps between the blades 5.

The impeller 4 comprises a hub 10 connected to the first support ring 6 and intended to be connected to the engine 3.

The hub 10 has a sleeve 11 for connection with the shaft 3A, while many legs 12 for connecting with the ring 6 extend from the said sleeve.

In addition, the hub 10 comprises a central portion 13 extending from the sleeve 11 between the legs 12 and restricting, together with the legs 12 and the support ring 6, a plurality of holes 14.

As shown, for example, in FIG. 2, 3 and 4, the engine 3 is partially inserted into the hub 10, while in the alternative embodiments not shown, the engine 3 is located outside the hub 10.

The aforementioned housing 2 has an axial inlet 15, that is, an opening whose axis coincides with the rotation axis R (and, accordingly, with the axis of the input 8 of the impeller 4), and a tangential outlet 16, which is located in a known manner relative to the impeller 4 and is intended for circulation of air moved by the impeller 4.

The housing 2 comprises a main compartment having a central part 17 in which an inlet 15 is formed, and an outlet channel 18 extending tangentially from the central part 17 and in fluid communication with said central part, with an outlet 16 located at the free end of said channel .

The fan 1 comprises a cover 19 for closing the housing 2, to which the motor 3 is preferably attached.

In fact, the cover 19 is located relative to the engine 3 from the side opposite to that of the impeller 4, and is connected to the Central part 17 of the main compartment of the housing.

The cover 19 forms a casing 20 for the engine 3, in which the engine 3 is partially located.

In particular, the lid 19 has an inner cylindrical side wall 21 and an inner rear wall 22 connected to the side wall 21 defining the casing 20, the engine 3 being located inside the casing 20 so that its axis coincides with the axis of the casing 20.

In particular, as shown in FIG. 5, the upper part 3b of the engine 3 is a part of the engine 3 located inside the casing 20, and the lower part 3c of the engine 3 is a part partially inserted into the hub 10.

Between the engine 3, in particular its upper part 3b, and the cover 19, an air circulation zone 32 is formed.

The fan 1 contains a cooling system designed to remove heat from the engine 3 through the flow of RF cooling air directed from the inside of the housing 2 beyond.

According to the present invention, as will be explained below, the RF flow of cooling air includes a tangential component and an axial component directed along the rotation axis R.

The tangential component and the axial component are added vectorly, forming as a result a spiral vortex RF around the engine 3.

According to a first embodiment of the present invention shown in FIG. 2, to create the aforementioned axial component, the cooling system of the engine 3 comprises an impeller 4 and a channel 30 having an inlet 26 in the outlet channel 18 and an outlet 27 in the central part 17, essentially the engine 3.

During operation, overpressure is created at the output 9 of the impeller 4, and also, in particular, at the inlet 26 of the channel 30.

This overpressure allows air to be pushed along the channel 30 from the inlet 26 to the outlet 27, and the air flow leaving the channel 30 forms the aforementioned axial component.

During operation, to create the aforementioned tangential component of the RF cooling stream, the cooling system comprises an annular element 28 integral with the impeller 4 and extending axially from the impeller 4 to the motor 3, outside of it, and a plurality of radial blades 29 supported ring element 28 and facing the engine 3.

The annular element 28 forms a single unit with the impeller 4 and extends from the support ring 6 from the side opposite to where the blades 5 are located.

Radial blades 29 pass between the support ring 6 and the outer annular element 28, and they extend from the said outer annular element towards the engine 3.

The outer annular element 28 together with the blades 29 surrounds the engine 3 and, in particular, the upper part 3b of the engine.

The aforementioned casing 20 is designed to contain, in addition to the engine 3, also the annular element 28 and, accordingly, the blades 29.

A set of blades, consisting of blades 29, together with the outer annular element 28, driven by rotation of the impeller 4 and forming a single unit with the mentioned impeller, creates a part of the cooling flow RF, which forms the aforementioned tangential component.

In other words, the rotation effect of the blades 29 is to move the air contained in the hollow space between the blades 29 and the engine 3, with the formation of the tangential component of the cooling stream RF.

The aforementioned axial component is preferably directed inside the housing 2 from the upper part 3b of the engine to the lower part 3c of the engine so that the cooling stream RF obtained by combining the tangential and axial components moves through the openings 14 of the hub 10 into the interior of the impeller 4, from where it is pushed out of the housing 2 through the outlet 16.

In the second embodiment of the present invention shown in FIG. 4 and 5, the cooling system comprises a hollow space 31, or an annular channel 31, formed between the cylindrical outer wall of the annular element 28 and the cylindrical side wall 21 of the casing 20.

The annular channel 31 provides fluid communication between the channel 18 and the central part 17 of the housing 2 at the upper part 3b of the engine 3.

In particular, the lid 19 has such a geometric shape that the annular hollow space 31 is in fluid communication with the channel 18.

In FIG. 5, reference numeral 31a indicates the input of the annular channel 31, and reference numeral 31b indicates the output of the channel 31.

This cooling system contains, as in the first embodiment of the present invention, an annular element 28 made integrally with the impeller 4 and extending axially from the impeller 4 to the motor 3, outside of it, and radial blades 29 supported by the annular element 28 and facing the engine 3.

The annular element 28 forms a single unit with the impeller 4 and extends from the support ring 6 from the side opposite to where the blades 5 are located.

Radial blades 29 pass between the support ring 6 and the outer annular element 28, and they extend from the said outer annular element towards the engine 3.

The outer annular element 28 together with the blades 29 surrounds the engine 3 and, in particular, the upper part 3b of the engine.

The aforementioned casing 20 is designed to contain, in addition to the engine 3, also the annular element 28 and, accordingly, the blades 29.

A set of blades, consisting of blades 29, together with the outer annular element 28, driven by rotation of the impeller 4 and forming a single unit with the mentioned impeller, creates a part of the cooling flow RF, which forms the aforementioned tangential component.

In other words, the rotation effect of the blades 29 is to move the air contained in the hollow space between the blades 29 and the engine 3, with the formation of the tangential component of the cooling stream RF.

During operation, the impeller 4 pushes air at high speed along the channel 18.

High-speed air flow creates a Venturi effect, which, in turn, creates a negative pressure at the outlet 31b of the channel 31.

Negative pressure causes the suction effect of the flow of cooling air along the hollow space 31.

In other words, a suction flow is generated in the annular channel 31, directed from the inlet 31a to the outlet 31b.

In fact, suction along the hollow space 31 creates in the central part 17 of the housing 2 a so-called axial component, essentially directed along the axis R of rotation of the engine 3 inside the housing 2.

This axial component is sucked into the impeller 4 through the input 8.

The axial component is preferably directed in the housing 2 from the lower part 3c of the engine to the upper part 3b of the engine so that the spiral cooling stream RF, obtained by combining the tangential and axial components, moves through the openings 14 of the hub 10 through the impeller 4 to the zone 32, from where it pushed out of the housing 2 through the hollow space 31 and the channel 18.

The axial component is combined with the tangential flow created by the blades 29, forming the aforementioned spiral vortex RF, transferred from the inner space of the housing 2 outside the housing 2 through the hollow space 31 and channel 18.

In the presently preferred embodiment of the present invention, the annular channel 31 has an outlet 31b formed between the cover 19 and the impeller 4 and having a size “h” of the same order of magnitude as the size “M” of the channel 31 between the annular element 28 and the cylindrical side wall 21 bounding the casing 20.

In other words, the cover 19 has such a geometric shape that it, together with the first support ring 6 and / or with the blades 5, forms an outlet 31b.

In the present embodiment, the outlet 31b of the annular channel 31 is preferably formed by a support ring 6 and, in particular, its annular rim 60 facing the corresponding annular part 19a of the cover 19.

The annular hollow space 31 communicates with the air circulation zone 32, where an inlet 31a is formed.

Thus, during operation, the flow moving along the hollow space 31 is combined in zone 32 with the tangential flow created by the blades 29, forming around the engine 3 the aforementioned spiral vortex RF, sucked into the channel 18.

In the aforementioned air circulation zone 32, the cooling air flow RF contacts the engine cover 3, removing heat from it.

An air circulation zone 32 is formed between the rear wall 22 of the casing 20 and the rear surface 33 of the engine 3 to which the wall is facing.

In fact, the inner part of the casing 20 has a space for air circulation both between the side wall and the cover 19, and between the base wall of the engine 3 and the cover 19.

A fan according to a third embodiment of the present invention is shown in FIG. 9.

In this embodiment, in comparison with the second embodiment of the invention, a number of centrifugal fan blades 40 located outside the annular element 28 and designed to push air from the hollow space 31 to the outlet of the channel 18 contribute to the absorption of the cooling flow through the hollow space 31.

The blades 40 of the centrifugal fan extend from the side opposite to the engine 3 and form a second auxiliary centrifugal fan 41, which additionally pushes the cooling flow resulting from the combination of the tangential and axial components from the hollow space 31 outside the housing 2.

The blades 40 are preferably integral with the annular element 28 and extend outside the annular element, which is also shown in FIG. 10.

In this preferred embodiment, presented as an example, each blade 40 is made in the form of an extension of the corresponding blade 5 of the impeller 4, as shown in FIG. 10.

Preferably, the cooling system and, in particular, the blades 29 are made so that the tangential component is an order of magnitude higher than the value of the axial component to ensure efficient heat removal from the engine 3.

The channel 30 external to the housing 2 in the first embodiment of the present invention and the hollow space or the annular channel 31 in the second and third embodiments of the present invention form a ventilation channel, which is part of the cooling system of the fan 1, due to which the RF cooling stream generated in the form of a spiral vortex, removes heat from the engine 3.

Thus, the high-speed air flow is in contact with the outer surface of the engine 3, which is especially effective for heat dissipation.

In other words, the rotation effect of the blades 29 is to move the air contained in the hollow space between the blades 29 and the engine 3, with the formation of the aforementioned tangential component.

The engine is covered by a spiral vortex, which is very effective for forced cooling without using an axial component, which negatively affects the efficiency and noise level of the fan.

The axial component is necessary for transferring the heat captured by the aforementioned RF vortex out of the “engine zone”.

A centrifugal fan equipped with the described cooling system provides the possibility of installing in it closed or sealed motors that work well in harsh environmental conditions, as well as motors with an integrated drive electronics.

The described cooling system allows to increase the service life of the fan to more than 30,000 hours of operation compared to fans known from the prior art.

The proposed solutions provide the maximum possible cooling of the engine driving the impeller, minimize the number of sources of gas-dynamic noise, and at the same time minimize costs at equal operating levels of performance due to the rejection of the use of the connecting channel between the fan outlet and the engine cover.

The use of an annular suction channel in the fan housing (axial component) allows to reduce, compared with solutions known from the prior art, the noise generated by air due to gas-dynamic factors, and vibration.

Claims (14)

1. Centrifugal fan containing an impeller (4) mounted rotatably around an axis of rotation (R), drive motor (3) of the impeller (4), a housing (2) comprising a central portion (18) for receiving said engine (3) and an impeller (4), and a tangential exhaust channel (18) in communication with said central portion (17), the housing (2) having the inlet (15) in the Central part (17) and the outlet (16) in the tangential exhaust channel (18), engine cooling system (4, 14, 28, 29) (3), comprising an impeller (4) and a ventilation duct (30, 31), functioning between the tangential exhaust channel (18) and the central part (17) and designed to create a flow cooling air characterized in that the said cooling system (4, 14, 28, 29) comprises an annular element (28) made integrally with the impeller (4) and extending axially from the impeller (4) around the engine (3), and a plurality of radial blades (29) supported by an annular element (28) and facing the engine (3) to create a tangential cooling component that combines with the flow of cooling air, resulting in a spiral vortex of RF around the engine (3). 2. The fan according to claim 1, in which the housing (2) comprises a cover (19) covering the central part (17) and located coaxially to the engine (3) from the side opposite to that of the impeller (4), the ventilation a channel is at least partially formed between the outer surface of the annular element and said cover. 3. The fan according to claim 2, in which the ventilation duct has an annular outlet (31b) formed between the cover (19) and the impeller (4) and having a size (h) of the same order of magnitude as the size (h1) of the ventilation duct (31) between the annular element (28) and the cover (19). 4. The fan according to any one of paragraphs. 1-3, in which the cooling system comprises a plurality of centrifugal fan blades (40) extending relative to the annular element from the side opposite to the engine (3) and intended to push the cooling flow along the tangential exhaust channel (18). 5. The fan according to claim 4, in which the blades (40) of the centrifugal fan extend from the annular element and form a single unit with said annular element. 6. The fan according to any one of paragraphs. 1-3 or 5, in which the annular element (28) and the first radial blades (29) are made in one piece with the impeller (4). 7. The fan according to any one of paragraphs. 1-3 or 5, in which the motor (3) is at least partially inserted into the impeller (4). 8. The fan according to any one of paragraphs. 1-3 or 5, in which the housing (2) contains a cover (19) that covers the Central part (17) and located coaxially to the engine (3) from the side opposite to that of the impeller (4), and the cover (19) ) has a cylindrical inner side wall (21) and an inner back wall (22) bounding the casing (20) in which the engine (3) is placed, the ventilation duct (30, 31) being formed between the annular element (28) and the cylindrical inner side wall, and between the inner rear wall (22) and the rear surface (33) of the engine (3) about azovana area (32) circulating air, wherein the vent (30, 31) and a zone (32) circulating communicate with each other in fluid communication. 9. A fan according to claim 1, wherein the ventilation duct is formed by a recirculation duct (30) outside the housing (2) having an input (26) in a tangential exhaust channel (18) and an output (27) in the central part (17).

Images