HK1049686B - Rotor ventilator - Google Patents

Description

Rotor ventilator

Technical Field

The present invention relates to ventilators, in particular rooftop (Roof-top) rotor ventilators.

The invention has been developed primarily for use as a rooftop ventilator and will be described hereinafter with reference to this application. It will be appreciated that the invention is not limited to this particular field of application.

Background

The use of a rooftop rotor-vented ventilator aids in the venting of exhaust air from a building in which the rotor ventilator is employed. These buildings may be factories, farms, warehouses or residential homes.

The mechanism of a rooftop rotor ventilator is: the flow of air through the ventilator will cause the ventilator to rotate about its vertical axis, the flow of air causing the vanes of the ventilator to force air out of the ventilator, resulting in a lower air pressure inside the ventilator than inside the building when the ventilator is in fluid communication with the ventilator. Accordingly, the air inside the building flows through the ventilator to be discharged to the outside of the building.

The efficiency of a rooftop rotor ventilator depends on a number of factors, including the starting torque required to turn the ventilator, the amount of friction that resists rotation of the ventilator, and the configuration of the vanes.

Disclosure of Invention

In the description and claims, the terms "upper", "above" and "lower" are used with respect to the rotor ventilator, in relation to the orientation of the rotor ventilator that is normally used. If the rotor ventilators are used in a sideways or inverted configuration, their orientation may be reversed. Thus, "upper", "above" and "lower" are to be understood broadly in this sense and as relative terms.

According to a first aspect of the present invention, there is provided a rotor ventilator comprising:

a base, a shaft connected to the base and extending upward from the base;

a rotor including a plate and a plurality of vanes extending downwardly from the plate, the rotor being rotatable about the shaft; and

a bearing device supporting the rotor on the shaft and disposed at the plate;

characterized in that the bearing device is a double-row rotary bearing.

The bearing means is preferably arranged above said plate.

Preferably, the double row rotary bearing comprises: a bearing housing, the bearing housing having a central bore and two axially spaced inner bearing raceways; a central shaft extending longitudinally through said bore to define a space between the bearing outer sleeve and the central shaft, said central shaft including two axially spaced inner bearing raceways, the raceways on said central shaft being aligned with the raceways on the bearing outer sleeve; a plurality of bearing balls sandwiched and engaged between the respective aligning raceways; and a low friction seal disposed at one end of the bearing housing and projecting radially inwardly toward the central axis.

Preferably, a radially inwardly projecting second seal is provided at the other end of the bearing outer sleeve.

The rotor ventilator preferably further comprises a bearing means mounted to the rotor and rotatably mounted to the shaft. The support means also preferably includes a rotational bearing means for rotatable mounting to the shaft, substantially centrally located between the plate and the housing.

Each blade of the rotor ventilator is preferably mounted to the plate by means of a joint fixture having at least one joint projection arranged in a corresponding slot in the plate.

Preferably, the centre of gravity of the rotor is below the bearing arrangement.

According to a second aspect of the present invention there is provided a rotor for a rotor ventilator, the rotor comprising a plurality of vanes extending from a support member, wherein the end of each vane has a tab projection for location in a corresponding slot in the support member.

According to a third aspect of the present invention, there is provided a rotor ventilator comprising: a base, a shaft connected to the base and extending upward from the base; a rotor including a plate and a plurality of vanes extending downwardly from the plate, the rotor being rotatable about the shaft; and a bearing device supporting the rotor on the shaft and disposed at the plate; the bearing means is a double row slew bearing assembly located wholly above the plate or wholly below the plate.

Drawings

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the following drawings:

FIG. 1 is a side view of a first preferred embodiment of the rotor fan of the present invention;

FIG. 2 is a plan view of the FIG. 1 rotor ventilator with the dome removed;

FIG. 3 is a cross-sectional side view of the rotor ventilator of FIG. 1;

FIG. 4 is a plan view of another embodiment of the rotor ventilator with the dome removed;

FIG. 5 is a cross-sectional side view of the rotor ventilator of FIG. 4; and

fig. 6 is a partial cross-sectional side view of a bearing.

Detailed Description

Referring to the drawings, like reference numbers indicate similar or identical elements. Fig. 1 to 3 and 6 show a first preferred embodiment of a rotor ventilator according to the present invention, which comprises a housing in the form of a hollow cylindrical housing part 10 for mounting on a roof, wall, ceiling, floor or the like. The base member 10 enables air to pass through its openings 11 and into the interior 12 of the rotor ventilator. A shaft 13 is connected to the base member and extends upwardly therefrom. To add lateral stability to the axle, a bracket 14 is typically used and the axle is mounted to the base member 10. The bracket 14 includes a lower frame arm and an upper frame arm. Each frame arm 15 and 16 is configured to ensure that air flow through the base unit 10 into the rotor ventilator interior 12 is substantially unimpeded.

Rotor 17 is rotatable about shaft 13, rotor 17 having a plate 18 and a plurality of vanes 19 extending downwardly from the plate. One end 20 of each vane 19 is mounted to the plate 18. In order to increase the stability of the vanes when the rotor 17 is rotated, the rotor fan further comprises a second plate in the form of an annular sleeve 21 mounted to the other end 22 of each vane.

In order to allow each blade 19 to be mounted between the plate 18 and the annular sleeve 21, in this embodiment each end 20 and 22 of each blade 19 has four projecting tabs 23, although in alternative embodiments there may be a different number of tabs 23 at each end 20 and 22. The tabs 23 are aligned in-plane with their respective blades 19 when the blades 19 are manufactured. The projecting tabs 23 are used to mount the ends 20 and 22 of each blade into the respective plate 18 and annulus 21. To achieve this mounting, the plate 18 and the annular sleeve 21 have grooves corresponding to the projecting tabs 23. To mount the ends 20 of the blades 19 to the plate 18, the tabs 23 are passed through their corresponding slots in the plate 18 and then folded laterally onto the plate in the mounted position shown in figures 2 and 3. This secures the ends 20 of the blades 19 to the plate 18. Likewise, in order to fix the end 22 of the blade 19 to the annular sleeve 21, the projecting tabs 23 on the end 22 are passed through corresponding perforations in the annular sleeve 21, and the tabs 23 are then superimposed on the end 20 in a similar manner. This secures the ends 22 of the blades 19 to the annular sleeve 21.

This method of mounting the blade to the plate 18 and the annulus 21 does not require additional fastening means. Rivets or screws as required to mount the blades 19 to the plate 18 and the annular sleeve 21, with the consequent advantages: reducing the overall weight of the rotor and reducing the manufacturing time and cost of manufacturing the rotor ventilator.

As the air flows over the blades 19 of the rotor, the leading edges 24 of the blades 19 catch the passing air that turns the rotor. In the case of the embodiment of the invention shown in fig. 1 to 5, the rotor is rotated in a clockwise direction by means of an air flow through the rotor ventilator. The movement of the blades 19 by the ambient air causes air inside the rotor ventilator to be expelled from the blades. The air inside the rotor ventilator is expelled from the blades as the trailing edge 25 penetrates the air present inside the rotor ventilator, forcing the air out of the rotor ventilator via the blades 19. This reduces the air pressure inside the rotor ventilator 12. In this way, air at a higher pressure is discharged through the openings 11 in the base member 10 into the ventilator and substantially out of the rotor ventilator.

The rotor ventilator further comprises bearing means in the form of a support structure 26 for supporting the rotation of the rotor 17 on the shaft 13. The support structure 26 is typically mounted on top of the plate 18 so that the point of support of the rotor 17 on the shaft 13 is above the centre of gravity of the rotor 17 and so that the support structure 26 remains within the rotor ventilator.

There are several advantages to having the support structure 26 on top of the slab 18. The position of the support structure 26 above the plate 18 means that the centre of gravity of the rotor 17 is just below the support point of the support structure 26 for the shaft 13. The rotor is thus essentially suspended from the support structure. This allows for greater stability of the rotor ventilator in use, since lateral movement of the rotor is reduced. Such lateral movement may occur if the support point is below the center of gravity. If the bearing point is below the center of gravity, the rotor will be unbalanced, causing the bearing point to develop lateral stresses. With a consequent reduction in the operating stresses of the supporting structure.

An additional advantage of having the support structure 26 on top of the plate 18 is that the corrosive gases are vented by a rotor ventilator. Because the support structure is above the plate 18, the support structure is not in contact with the exhaust gases as the gases are exhausted below the plate 18 via the vanes 19.

In another embodiment, the support structure is configured to ensure that the center of gravity of the rotor 17 is located below the support structure 26.

The support structure includes a fitting 27 for fixed mounting to the plate 18. In the preferred embodiment shown in fig. 2 and 3, the fitting 27 has three relatively long radially spaced support arms 28 and three relatively short radially spaced support arms 29. These arms 28 and 29 serve to stably secure the support structure to the plate 18. The arms are typically riveted to the plate 18, but may be welded or screwed in place.

The support structure 26 also includes a bearing assembly in the form of a double row ball bearing assembly 30. As shown in FIG. 6, the double row ball bearing device 30 includes a center shaft 32, and an outer sleeve 34 that rotates on the center shaft 32. The central shaft 32 and outer sleeve 34 carry respective bearing ball tracks 36 and 38 between which a plurality of bearing balls 40 orbit to support the structure.

The double row ball bearing arrangement 30 is fixedly arranged centrally in the fitting 27 such that the central axis 32 is in axial alignment with the central axis of the plate 18. When the double row ball bearing device is fixed in the fitting 27, the outer sleeve is fixed relative to the fitting 27, while the central shaft 32 is free to rotate relative to the outer sleeve 34.

To enable rotor 17 to be rotatably mounted about shaft 13, an end 42 of central shaft 32 is mounted to an end 44 of shaft 13 such that shafts 13 and 32 are coaxially aligned and secured together.

The rotor ventilator typically has a dome 45 which is arranged on top of the rotor ventilator to cover the support structure 26 and reduce the resistance to the flow of air around the rotor ventilator. The lower side 47 of the annulus 21 is also typically fitted with a shroud 46. And also helps to reduce the resistance to air flow around the rotor ventilator.

The preferred embodiment of the rotor ventilator described above is for a rotor ventilator having a diameter of about 700mm and a height of about 460 mm. For ventilators of this and smaller dimensions, the double row race ball bearing arrangement 30 is typically required to maintain lateral stability of the rotor 17 during use. The rotor fan with a simple bearing device is provided, so that the rotor fan has the advantages of easy manufacture and low manufacture cost, and the rotor can rotate effectively and stably only by the simple bearing device.

The double row ball bearing arrangement for use with the present invention is not known as a precaution to reduce the frictional rotational support of the rotor ventilator. The double row ball bearing arrangement of the type employed in the present invention was developed for use in motors or the like in wet environments and therefore employs high friction seals to ensure that no water passes into the bearing balls and bearing raceways. A person skilled in the art and familiar with the art of non-invasiveness would not recognize the use of such a double row ball bearing arrangement in a rotor ventilator application such as the rotor ventilator of the present invention.

The present invention surprisingly found that: by replacing the high friction seal with a low friction, no/low contact seal. The double row bearing arrangement 30 is suitable for use in a rotor fan as a ball bearing arrangement and has several advantages compared to a single row ball bearing arrangement.

In the case of a double row ball bearing arrangement, one example of the advantages is: the double row ball bearing device has better transverse stability and strength than a single-ring ball bearing device. Therefore, in the case of the smaller rotor ventilator example as illustrated in figure 3, a double row ball bearing arrangement is required to maintain sufficient lateral stability of the rotor. It is not sufficient to use a single row ball bearing arrangement. Another example is: enhancing the stability and strength of the double row ball bearing arrangement 30 means that it is possible to arrange the ball bearing arrangement 30 above the plate 18 and still maintain sufficient lateral stability under certain conditions.

Referring now to fig. 4 and 5, in which like reference numerals refer to similar or identical parts, another embodiment of the rotor ventilator is shown that is larger than the rotor ventilators described above. Additional support means in the form of intermediate supports 48 to improve the lateral stability of the larger rotor in use. The intermediate support 48 includes a structural member 49 having ends 50 and 52. End 50 is mounted to plate 18 and end 52 is mounted to annulus 21. Structural arms 54 extend transversely from structural member 49 toward shaft 13. The end 55 of the arm 54 is connected to a star wheel support 56, which star wheel support 56 is rotatably mounted on the shaft 13.

In use, the holes required for the improved ventilator are provided, for example, on the roof of a building. The base member 10 is typically fixedly attached to the roof in such a way that the shaft 13 is in a substantially vertical position and the rotor 17 is free to rotate about the shaft 13. Thus, as air passes through the rotor ventilator and causes the rotor 17 to rotate as described above, air expelled from the rotor ventilator interior 12 is replaced by air from below the roof. Then exhaust gas is discharged, and the effect of improving ventilation is achieved.

Although the present invention has been described with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention may be embodied in many other forms.

Claims (19)

1. A rotor ventilator comprising:

a base, a shaft connected to the base and extending upward from the base;

a rotor including a plate and a plurality of vanes extending downwardly from the plate, the rotor being rotatable about the shaft; and

a bearing device supporting the rotor on the shaft and disposed at the plate;

characterized in that the bearing device is a double-row rotary bearing.

2. A rotor ventilator according to claim 1, wherein the double row rotary bearing is disposed above the plate.

3. A rotor ventilator according to claim 1 or 2, wherein the double-row rotary bearing comprises:

a bearing housing, the bearing housing having a central bore and two axially spaced inner bearing raceways;

a central shaft extending longitudinally through said bore to define a space between the bearing outer sleeve and the central shaft, said central shaft including two axially spaced inner bearing raceways, the raceways on said central shaft being aligned with the raceways on the bearing outer sleeve;

a plurality of bearing balls sandwiched and engaged between the respective aligning raceways; and

a low friction seal is disposed at one end of the bearing housing and projects radially inwardly toward the central axis.

4. A rotor ventilator according to claim 3, further comprising a radially inwardly projecting second seal member disposed at the other end portion of the bearing housing.

5. A rotor ventilator according to claim 1 or 2, wherein the rotor ventilator further comprises a bearing means having one end rotatably mounted on the shaft and the other end of the rotor.

6. A rotor ventilator according to claim 5, wherein said one end portion of the support means includes a bearing means for rotatable mounting on said shaft.

7. A rotor ventilator according to claim 5, wherein the support means is centrally located between the plate and the housing.

8. A rotor ventilator according to claim 1 or 2, wherein each end of each vane is mounted to the plate by a joint fixture means comprising at least one joint projection that is disposed in a corresponding slot in the plate.

9. A rotor ventilator according to claim 1 or 2, wherein the centre of gravity of the rotor is below the bearing arrangement.

10. A rotor for use in a rotor ventilator, the rotor comprising a plurality of vanes extending from a support member, characterised in that the end of each vane has a tab projection for fitting within a corresponding slot in the support member.

11. A rotor ventilator comprising:

a base, a shaft connected to the base and extending upward from the base;

a rotor including a plate and a plurality of vanes extending downwardly from the plate, the rotor being rotatable about the shaft; and

a bearing device supporting the rotor on the shaft and disposed at the plate;

characterized in that the bearing means is a double row rolling bearing assembly located wholly above the plate or wholly below the plate.

12. A rotor ventilator according to claim 11, wherein the double row rotary bearing assembly is a double row rotary bearing assembly.

13. A rotor ventilator according to claim 11 or 12, wherein the double-row rotary bearing comprises:

a bearing housing, the bearing housing having a central bore and two axially spaced inner bearing raceways;

a central shaft extending longitudinally through said bore to define a space between the bearing outer sleeve and the central shaft, said central shaft including two axially spaced inner bearing raceways, the raceways on said central shaft being aligned with the raceways on the bearing outer sleeve;

a plurality of bearing balls sandwiched and engaged between the respective aligning raceways; and

a low friction seal is disposed at one end of the bearing housing and projects radially inwardly toward the central axis.

14. A rotor ventilator according to claim 13, further comprising a radially inwardly projecting second seal member disposed at the other end portion of the bearing housing.

15. A rotor ventilator according to claim 11 or 12, wherein the rotor ventilator further comprises a bearing means having one end rotatably mounted on the shaft and the other end of the rotor.

16. A rotor ventilator according to claim 15, wherein said one end portion of the support means includes a bearing means for rotatably mounting on said shaft.

17. A rotor ventilator according to claim 15, wherein the support means is centrally located between the plate and the housing.

18. A rotor ventilator according to claim 11 or 12, wherein each end of each vane is mounted to the plate by a joint fixture means comprising at least one joint projection that is disposed in a corresponding slot in the plate.

19. A rotor ventilator according to claim 11 or 12, wherein the centre of gravity of the rotor is below the bearing arrangement.