Patent Application
20220034328
The disclosure relates to a radial ventilator and, more specifically, to a high-speed radial ventilator in a compact construction.
Radial ventilators of the type are known from the prior art, for example from German utility model DE 202018106694 U1.
Corresponding radial ventilators include multiple housing parts to receive the motor and forming the flow path from the intake via the pressure chamber to the discharge. The flow is to be conveyed as optimally as possible from the intake to the discharge, at the same time. Good flow conditions improve the efficiency, the pressure buildup, and the acoustics of the radial fan. Radial ventilators typically have a spiral-type housing, that receives the rapid flow emitted by the radial wheel, decelerates it, and finally converts it into usable pressure. A smooth deceleration is advantageous for the pressure buildup.
The disclosure is based on the object of providing a radial ventilator that has a compact structure with a small number of parts. At the same time, it has a high efficiency with improved acoustics.
This object is achieved by a radial ventilator comprising: a base part, a housing part placed on the base part, a motor electronics unit and an internal rotor electric motor; a ventilator wheel drive via a shaft with electric motor; with a discharge, the motor electronics unit and a stator of the electric motor are encapsulated by extrusion coating in the base part and together form an integral one-piece structural unit; the radial ventilator has a pressure chamber expanding in a spiral shape around the ventilator wheel.
According to the disclosure, a radial ventilator has a base part, a housing part placed on the base part with a discharge. A motor electronics unit and an internal rotor electric motor is included. The electric motor drives a ventilator wheel via a shaft. The motor electronics unit and a stator of the electric motor are encapsulated in the base part by an extrusion coating. Together they form an integral one-piece structural unit. The radial ventilator moreover has a pressure chamber expanding in a spiral shape around the ventilator wheel. It is formed and defined by the housing part and the extrusion coating.
For example, a thermosetting plastic based on epoxy is used as the extrusion coating and processed in an injection molding. The extrusion coating forms the structure of the base part to receive the motor electronics unit and the stator. Corresponding cavities are provided for this purpose in the extrusion coating. Moreover, plug devices for electrically connecting the radial ventilator, for example a connection plug or a plug housing, can also be integrated into the extrusion coating and in particular formed on the outside on the base part.
The one-piece design of the extrusion coating is used together with the housing part in order to provide the spiral-shaped geometry of the pressure chamber. Additional components are not required.
In one advantageous embodiment of the radial fan, the extrusion coating comprises a protruding ring section extending in the axial direction in relation to the housing part. The axial end face defines the pressure chamber. Moreover, the ring section protrudes enough in relation to the remaining region of the base part that it provides a receptacle chamber for the motor electronics unit which is media-separated from the pressure chamber. It encloses the motor electronics components. The axial extension of the ring section and the axial end face are geometrically established so that the spiral shape of the pressure chamber is formed. Preferably, the spiral-shaped pressure chamber is created by an axial and radial expansion. The radial expansion takes place over the width of the axial end face and the axial expansion takes place over the axial height of the ring section.
In one embodiment, the radial ventilator housing part has a constant diameter delimiting the pressure chamber. A spiral shape of the pressure chamber is exclusively defined by the extrusion coating or the protruding ring section. The structural space of the radial ventilator is particularly compact in this embodiment.
An embodiment is also advantageous where the electric motor is arranged on a first axial side of the motor electronics unit. The pressure chamber is arranged on a second axial side of the motor electronics unit, which is opposite to the first axial side. The motor electronics unit can thus be cooled via the adjoining flow through the pressure chamber. At the same time, the motor group is separated from the flow by the motor electronics unit arranged axially in between the two.
The motor electronics unit is preferably arranged on a printed circuit board. The printed circuit board is also completely enclosed by the extrusion coating. The fixing of the printed circuit board and the motor electronics unit or the motor electronics components arranged on the printed circuit board in the base part is carried out directly by the extrusion coating.
In one refinement, the radial ventilator base part has a cylindrical recess around a rotational axis for the shaft, where a rotor of the electric motor fastened on the shaft is inserted. The cylindrical recess replicates a containment shroud of a containment shroud motor. The stator is positioned in the extrusion coating radially adjoining the recess. Thus, the rotor fastened on the shaft interacts with the stator when it is inserted in the recess and implements a containment shroud motor structure.
The recess has a closed bottom. The bottom is formed by the extrusion coating. The motor is thus completely encapsulated in the base part.
One refinement of the radial ventilator provides that a ring-shaped flow divider enclosing the ventilator wheel is arranged radially adjoining the ventilator wheel. Together with the housing part it forms a diffuser, that merges directly into the pressure chamber, around the ventilator wheel.
For the ventilator wheel, it is important that it has a uniform counter pressure at the outlet over the entire circumference. Each blade of the ventilator wheel thus provides an optimum contribution to the flow. An uneven pressure distribution around the ventilator wheel would result in negative and undesired flow separations and back flows into the ventilator wheel. For the advantageous pressure buildup from the ventilator wheel in the pressure chamber, the flow divider is provided around the ventilator wheel. The ventilator wheel, together with the ventilator housing, provides a diffuser for the flow exiting from the ventilator wheel. It has a direct flow connection to the pressure chamber and provides a uniform counter pressure for the ventilator wheel. The radially expelled air flows through the diffuser from the radial inside to the radial outside up to its radial end and then enters the pressure chamber.
Naturally, the entry into the pressure chamber is located radially adjoining the diffuser, however, the spiral-shaped pressure chamber itself is preferably formed axially adjoining the diffuser in an adjacent axial plane. Thus, the flow from the flow divider flows tangentially into the pressure chamber. The flow divider can extend far radially outward, so that the inflow takes place into the radial outside region of the housing part. Thus, its spiral-shaped pressure chamber and generates a defined corkscrew turbulence at the same time. Turbulence losses in the spiral-shaped pressure chamber can thus be reduced.
In one advantageous compact interaction of the components, the flow divider rests on the extrusion coating.
Furthermore, in one advantageous embodiment of the radial ventilator provides that the flow divider is formed as a sleeve that is inserted into the recess that replicates the containment shroud. The formation as a sleeve enables the flow divider to take over additional functions, for example mounting the shaft. Its position can be established at the same time in this way.
It is advantageous from a fluidic viewpoint that the flow divider protrudes in the radial direction in relation to a radial inner wall surface of the extrusion coating and thus forms an axial surface of the pressure chamber. The spiral-shaped pressure chamber is located axially adjoining the diffuser. The flow divider advantageously forms a flow surface for the diffuser on a first axial side and forms an axial wall surface for the spiral-shaped pressure chamber on an opposing axial surface.
In one embodiment, the flow divider has a cup-like axial indentation with a diameter that corresponds to an external diameter of the ventilator wheel. The ventilator wheel is inserted axially in sections into the indentation. Thus, the flow discharged by the ventilator wheel is influenced immediately by the radially adjoining section of the flow divider that forms the diffuser. The indentation enables an axially compact construction of ventilator wheel and flow divider.
Furthermore, in one embodiment variant, the radial ventilator comprises at least one bearing for mounting the shaft. It is arranged between the flow divider and the shaft. Two axially spaced-apart bearings are preferably provided. They are tensioned via a spring and are each arranged between the flow divider and the shaft.
The radial ventilator, in one refinement, flow divider has a rounding at least in sections on its free end facing toward the pressure chamber. In particular, the rounding is provided on a radial end of the diffuser in order to improve the tangential inflow into the pressure chamber.
As a further embodiment variant of the radial ventilator, the axially protruding ring section of the extrusion coating has, on its radial outer edge section, a circumferential axial projection that presses against an inner wall surface of the housing part. An axial indentation in the inner part in the pressure chamber results. Thus, a sufficient contact surface between the ring section of the extrusion coating and the housing part is ensured at the same time via the circumferential projection.
Other advantageous refinements of the disclosure are characterized in the dependent claims or are described in greater detail in the following together with the description of the preferred embodiment of the disclosure on the basis of the figures.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
An exemplary embodiment of a radial ventilator 1 according to the disclosure is shown in an axial top view, two sectional views A-A and B-B, and a perspective sectional view in
The radial ventilator 1 comprises an electric motor designed as an internal rotor motor having a rotor 22 and a stator 32, that interact in the manner of a containment shroud motor. The magnets of the rotor 22 are fastened on the shaft 7, that extends along the rotational axis RA axially through the radial ventilator 1. The ventilator wheel 3 designed as a radial ventilator wheel, is fixed on the shaft 7. In operation, the ventilator wheel 3 suctions in air axially via the inlet 69 and discharges it via the pressure nozzle 33 at the discharge 44 via its impeller blades.
The radial ventilator 1 has the base part 2 and the housing part 4 placed on the base part 2 that has the pressure nozzle 33, that defines the discharge 44. The base part 2 is an integral one-piece structural unit. The stator 32 of the electric motor, the printed circuit board 10, and the motor electronics components 98 fixed on the printed circuit board 10 for regulating the radial ventilator 1 are encapsulated by the one-piece plastic extrusion coating 17 of the base part 2. The cylindrical recess 92 is formed in the base part 2 around the rotational axis RA of the shaft 7. The shaft 7 and the rotor 22 of the electric motor, fastened thereon, are inserted into the recess 92 in such a way that the rotor 22 and stator 32 lie on one axial plane. The bottom 77 of the recess 92 is closed by the extrusion coating 17. The extrusion coating 17 forms the protruding ring section 11 extending in the axial direction in parallel to the rotational axis. The axial end face of the ring section 11, facing toward the housing part 4, defines the spiral-shaped pressure chamber D together with the housing part 4. The axial projection 18 is formed on the radial outside on the ring section 11, which forms a contact surface to the inner wall surface of the housing part 4. The axial end face of the ring section 11 is thus indented like a trough. At the same time, the ring section 11 forms a receptacle chamber located on the radial inside for the motor electronics unit 98, as may be seen well in
The ring-shaped flow divider 8 enclosing the ventilator wheel 3 is arranged radially adjoining the ventilator wheel 3. The flow divider 8, together with the inner wall surface of the housing part 4, forms the diffuser 9 around the ventilator wheel 3. The inner wall surface of the outer part 4 and the flow divider 8 extend radially outward perpendicularly to the rotational axis RA in the region of the diffuser 9. The free end of the flow divider 8 forms the end of the diffuser 9 and has a rounding R. The diffuser 9 merges directly into the pressure chamber D. The spiral shape of the pressure chamber D is exclusively formed via the inner part 5 and, the housing part 4 having a constant diameter. It can be seen well with reference to
The housing part 4 is sealed via a circumferential seal 25 in relation to the base part 2 on the radial outer wall surface of the ring section 11. Furthermore, a plug device 93, for plugging in a plug and contacting with the printed circuit board 10, is provided in one piece on the base part 2.
The electronics components 98 are arranged, extrusion coated by the extrusion coating 17, in the free space adjoining the pressure chamber D and thus facing toward the flow. Thus, a heat emission to the flow divider 8 and thus cooling take place.
The flow divider 8 rests on the ring section 11 and is formed as a sleeve. It has a cylindrical tube section inserted in the axial direction into the recess 92, that ends spaced apart from the rotor 22. The shaft 7 is mounted on the flow divider 8 via two bearings 19. The two bearings 19 are tensioned in the axial direction via the spring 21. Alternatively, the shaft 7 can also be mounted opposite to recess 92 in the base part 2. In addition, it is also possible to mount one of the bearings 19 opposite to the flow divider 8 and the second bearing 19 opposite to the base part 2.
On the side of the ventilator wheel 3, the flow divider 8 has a cup-like axial indentation 14, in which the ventilator wheel 3 is inserted with its bottom disc. Thus, the outlet of the ventilator wheel 3 and the surface of the adjoining flow divider 8 lie flush in one axial plane. The diameter of the indentation 14 is equal to the external diameter of the bottom disc of the ventilator wheel 3, so that an essentially gap-free transition is produced from the ventilator wheel 3 to the flow divider 8. A minimal gap of preferably 0.2-0.5 mm is provided to ensure the rotation of the ventilator wheel 3. Essentially gap-free herein means that the rotation of the ventilator wheel 3 in relation to the flow divider 8 is ensured.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 129 608.8 | Nov 2018 | DE | national |
| 10 2018 129 611.8 | Nov 2018 | DE | national |
| 10 2018 129 613.4 | Nov 2018 | DE | national |
This application is a 371 U.S. National Phase of International Application No. PCT/EP2019/062392, filed May 14, 2019, which claims priority to German Patent Application Numbers. 10 2018 129 613.4 filed Nov. 23, 2018; 10 2018 129 611.8, filed Nov. 23, 2018 and 10 2018 129 608.8, filed Nov. 23, 2018. The entire disclosures of the above applications are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/062392 | 5/14/2019 | WO | 00 |
