Fan assembly

Abstract

A fan assembly (10) includes a housing (20) with an air inlet (70), a fan inlet (60), and an air outlet (80). The fan assembly further includes an impeller (30) and a motor (40) configured to drive the impeller, the impeller having a plurality of circumferentially positioned spaced blades (34). An air-permeable guard (50) is positioned between the air inlet and the fan inlet to prevent users from touching the impeller (30), and is spaced a first distance (54) from the fan inlet (60), and a second distance from the air inlet (70) so that a filter (90) may be provided between the air inlet (70) and the air-permeable guard (50). Preferably, the first distance (54) is such so as to allow incoming air to at least partially rotate prior to entering the fan inlet. Preferably, the plurality of circumferentially positioned spaced blades (34) is positioned circumferentially around a domed center (32) of the impeller (30), the domed center (32) facing the fan inlet (60), and the domed center (32) co-rotates with the spaced blades (34).

Description

FIELD OF THE INVENTION[0001]The present disclosure is directed generally to a fan assembly that improves efficiency and lowers power consumption.BACKGROUND OF THE INVENTION[0002]Fresh, clean air is one of the most basic needs for human beings. However, air can contain many different kinds of impurities, including particulates, viruses, bacteria, and fungi, all of which can cause or aggravate health issues, illness, and other negative outcomes. In order to improve air quality, there are many different technologies that clean air, the most common of which is an air filter. In general, filters clean air by means of a fan that pushes and / or pulls the air through the filter unit.[0003]In order to push or pull air through an air filter in an air purifying unit there are several different fan types, including radial fans and axial fans. Axial fans generate high flowrates, but result in relatively low maximum pressures. In contrast, radial fans generate relatively high maximum pressures but...

AI Technical Summary

Benefits of technology

[0006]The present disclosure is directed to inventive methods and apparatus for a fan and impeller configuration. Various embodiments and implementations herein are directed to a fan assembly that increases efficiency and lowers power consumption. Generally, in one aspect, a fan assembly comprises a housing with an air inlet, a fan inlet, and an air outlet; and an impeller comprising a plurality of circumferentially positioned spaced blades, and a motor configured to drive the impeller. The fan assembly has an air-permeable guard which is positioned between the air inlet and the fan inlet to prevent users from touching the impeller. The air-permeable guard is spaced a first distance from the fan inlet, and a second distance from the air inlet so that a filter may be provided between the air inlet and the air-permeable guard. Using the various embodiments and implementations herein, the fan assembly reduces the drop in pressure experienced by air as it enters the impeller region as a result of the larger cross-sectional area that the air-permeable guard may have if it is not confined to the area available for the relatively small fan inlet because it is placed at the first distance from the fan inlet. The fan assembly preferably also allows air to have a rotational component as it enters the air inlet and impeller region.

[0007]Applicant has further recognized that the prior art inlet configuration limits the rotational component of the air before it encounters the region of the fan blades, thereby limiting the performance of the fan in terms of maximum pressure as well as maximum flow. By positioning the air-permeable guard at a predetermined distance from the fan inlet, in an embodiment, the incoming air is allowed to at least partially rotate prior to entering the fan inlet. This results in a significant improvement in fan performance.

[0008]According to a preferred embodiment, the plurality of circumferentially positioned spaced blades is positioned circumferentially around a domed center of the impeller, the domed center facing the fan inlet, and wherein the domed center co-rotates with the spaced blades. This will reduce resistance for the airflow, as the air can rotate with the rotating center of the dome, which results in an increased efficiency.

[0009]According to an embodiment, each of the plurality of circumferentially positioned spaced blades is curved. This results in a higher performance.

[0010]According to an embodiment, the domed center of the impeller has a plurality of spokes. This results in less noise.

[0011]According to an embodiment, the maximum height of the domed center is approximately 1 to 75% of the maximum height of the impeller. According to another embodiment the maximum height of the domed center is approximately 1 to 60% of the maximum height of the impeller, and according to yet another embodiment the maximum height of the domed center is approximately 1 to 50% of the maximum height of the impeller. If the dome is higher, air will bump on the dome thereby increasing resistance and reducing performance. The dome is present to provide room for the motor.

Problems solved by technology

Applicant has further recognized that the prior art inlet configuration limits the rotational component of the air before it encounters the region of the fan blades, thereby limiting the performance of the fan in terms of maximum pressure as well as maximum flow.

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