CENTRIFUGAL BLOWER HAVING AN INTEGRATED COOLING FUNCTION

Abstract

A radial fan (1) or centrifugal blower is provided having a fan housing (2) with a spiral pressure chamber (D) and a rotor assembly (10) comprising an internally axially open bearing tube (20), in which a shaft (40) carrying a fan wheel (30) is mounted with a rotor (50) of a canned motor. An air-guiding channel (L) between a first pressure-chamber region (2a) and a second pressure-chamber region (2b) of the spiral pressure chamber (D) is formed between the bearing tube (20) and the wall (W) of the canned motor, so that an air flow flows through the air-guiding channel (L) from one pressure-chamber region (2a, 2b) to the other and in the process dissipates heat from the bearing tube (20) into the pressure chamber (D).

Claims

1. A radial fan (1) with a fan housing (2) with a spiral pressure chamber (D) and a rotor assembly (10) comprising an internally axially open bearing tube (20), in which a shaft (40) carrying a fan wheel (30) is mounted with a rotor (50) of a canned motor, wherein an air-guiding channel (L) between a first pressure-chamber region (2a) and a second pressure-chamber region (2b) of the spiral pressure chamber (D) is formed between the bearing tube (20) and the wall (W) of the separating can (3) of the canned motor, so that an air flow flows through the air-guiding channel (L) from one pressure-chamber region (2a, 2b) to the other and in the process dissipates heat from the bearing tube (20) into the pressure chamber (D).

2. The radial fan (1) according to claim 1, characterized in that at least one air channel opening (L1) opens directly into the pressure chamber (D).

3. The radial fan (1) according to claim 2, characterized in that at least the air channel opening (L1) is arranged in a region in the pressure chamber (D) in which the pressure during the operation of the fan is higher with respect to an air channel outlet (L2) of the air channel (L).

4. The radial fan (1) according to claim 1, characterized in that a projection (21) is formed by the bearing tube (20) and is designed as a substantially round plate-like projection, the diameter D.sub.A of which is greater than the diameter D.sub.V of the fan wheel.

5. The radial fan (1) according to claim 1, characterized in that multiple air-guiding channels (L) form a common air channel system and they are connected to one another so that an air flow flows through the air channel system from one pressure-chamber region to the other (2a, 2b) and in the process dissipates heat from the bearing tube (20) into the pressure chamber (D) via the multiple air-guiding channels (L).

6. The radial fan (1) according to claim 5, characterized in that the air-guiding channel(s) (L) is/are formed in the fan housing (2).

7. The radial fan (1) according to claim 5, wherein a projection (21) is formed by the bearing tube (20) and is designed as a substantially round plate-like projection, the diameter D.sub.A of which is greater than the diameter D.sub.V of the fan wheel and further characterized in that the air-guiding channels (L) are formed in a region beneath the projection (21) and are delimited by the projection (21).

8. The radial fan (1) according to claim 1, characterized in that at least one air-guiding channel (L) extends through a housing bottom plate (2a) of the fan housing (2), plate which is located flat beneath the fan wheel (30).

9. The radial fan (1) according to claim 1, characterized in that the opening to the air-guiding channel (L) in the first pressure chamber region (2a) and the opening to the air guide channel (L) in the second pressure chamber region (2b) of the spiral pressure chamber (D) are provided in diametrically opposite positions.

10. The radial fan (1) according to claim 1, wherein a projection (21) is formed by the bearing tube (20) and is designed as a substantially round plate-like projection, the diameter D.sub.A of which is greater than the diameter D.sub.V of the fan wheel and further characterized in that the projection (21) is located between the housing bottom plate (2a) of the fan housing (2) and the fan wheel (30), and the bearing tube (20) with its radial projection (21) rests flat on a housing bottom plate (2a) of the fan housing (2).

11. The radial fan (1) according to claim 1, characterized in that the shaft (40) is mounted on a first bearing (24) arranged in the bearing tube (20) and on a second bearing (25) arranged spaced axially therefrom in the bearing tube (20) in a region between the fan wheel (30) and the rotor (50), and the air-guiding channel (L) extends so that an air flow flows around the region of the bearings (24, 25).

12. The radial fan (1) according to claim 1, characterized in that the separating can (3) is designed so as to form a single piece with the fan housing (2).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Additional advantageous developments of the disclosure are characterized in the dependent claims and represented in further detail below together with the description of the preferred embodiment of the disclosure in reference to the figures.

[0022] FIG. 1 is a lateral cross-sectional view of an embodiment example of a radial fan,

[0023] FIG. 2 is a perspective cross-sectional view through the radial fan according to FIG. 1,

[0024] FIG. 3 is a perspective view onto the embodiment example according to FIG. 2 with open fan housing,

[0025] FIG. 4 is a perspective view onto the embodiment example according to FIG. 3, but without the fan wheel and without the rotor assembly with collar, and

[0026] FIGS. 5, 6, 7, 8 and 9 are additional example embodiments.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0027] Below, example embodiments are described in further detail in reference to FIGS. 1 to 9, wherein identical references denote identical structural and/or functional features.

[0028] In FIG. 1, an embodiment example of a radial fan 1 is shown.

[0029] The radial fan 1 comprises a rotor assembly 10. Said rotor assembly is designed for a high rotational speed radial fan. The rotor assembly 10 comprises an internally axially open bearing tube 20. In the bearing tube 20, a shaft 40 is mounted, wherein, on the shaft 40, a rotor 50 of a canned motor is mounted. The external stator 51 of the motor can also be seen in FIGS. 1 and 2. The bearing tube 20 comprises an outward protruding radial projection 21. This projection 21 extends over the outer circumference 31 of the fan wheel 30.

[0030] In the cross-sectional view according to FIG. 1, as well as in the perspective cross-sectional view of FIG. 2, it can easily be seen that the projection 21 extends over the outer circumference 31 of the fan wheel 30. The projection 21 is designed substantially as a round plate-like projection, the diameter of which is greater than the diameter of the fan wheel 30. The fan wheel 30 is placed on the shaft 40 so that the fan wheel 30 is arranged in the recess in the projection 21.

[0031] The radial fan 1 has a fan housing 2 with a spiral pressure chamber D. The rotor 50 which is positioned on the shaft 40 is mounted as a canned motor in the separating can 3, wherein an air-guiding channel L between a first pressure chamber region 2a and a second pressure chamber region 2b of the spiral pressure chamber D is formed between the bearing tube 20 and the wall of the separating can 3 of the canned motor, so that an air flow flows through the air-guiding channel L from one pressure chamber region 2a, 2b to the other and in the process dissipates heat from the bearing tube 20 into the pressure chamber D.

[0032] The shaft 40 is mounted between the two bearings 24, 25, wherein a spring 28 is preloaded and braces against the first bearing 24. The second bearing (in FIG. 1 lower bearing 25) sits on the lower end of the bearing tube 20. Through the lower bearing 25, the shaft 40 with the rotor 50 extends.

[0033] The bearing tube 20 rests by means of its radial projection 21 on the housing bottom plate 5 and is attached to the fan housing 2 by means of a screw connection. In the embodiment represented here, the air channel openings L1, L2 of the air-guiding channel L open directly into the pressure chamber D, as can easily be seen in FIG. 4. Furthermore, in FIG. 4, it can be seen that the two partial air-guiding channels in each case are designed in the fan housing 2 as groove-like recesses and extend in each case from the pressure chamber D to the separating can 3.

[0034] In FIGS. 5 to 9, additional embodiments of the disclosure are found, wherein, in particular, the design of the housing 2, of the separating can 3, of the bearing tube 20, and the design of the heat dissipation section 23 has occurred in an alternative form. The projection of the separating can 3v, which extends between a housing upper portion and a housing lower portion of the housing 2, can also be seen. In FIG. 9, it can moreover be seen that, in the region of the heat dissipation section 23, an attachment opening is provided, in order to attach the projection of the bearing tube 20 to the projection of the separating can 3.

[0035] The embodiments of the disclosure are not limited to the above-mentioned preferred embodiment examples. Instead, a number of variants are conceivable, which use the represented solution, even in embodiments of fundamentally different type. Thus, the represented air-guiding channel, for example, can also be formed by a plurality of channels.