Patent Application
20180142693
This document relates generally to blower assemblies used in a vehicle, and more specifically to inlet rings used in such assemblies to reduce tonal noise.
Blower assemblies are a common component of vehicle HVAC systems and are designed for maximum efficiency/airflow. As shown generally in
In operation, the motor 26 rotates output shaft 24 which in turn rotates the blower wheel 20 and blades 22. Ambient air is drawn through an inlet of side wall 16 and across the plurality of blades 22 creating an internal airflow. The airflow includes an ambient airflow entering the housing 12 across an inlet ring 30 and an internal airflow (generally shown by arrows 28) within the housing 12. The internal airflow 28 travels from the blower wheel blades 22 through an air gap adjacent a scroll cut-off 31 within an airflow path. The internal airflow 28 continues around the scrolled wall 14 of the housing 12 before exiting the housing at an airflow outlet or vent 32.
As suggested above, the blower assembly 10 further includes an inlet ring 30 attached to the housing 12. The inlet ring 30, shown in cross section in
As best portrayed in
In an effort to reduce the unwanted vibration and noise associated with the above-described blower assembly 10, an air block 48 extending substantially vertically from the proximal end 44 of the exterior surface 40 of the labyrinth seal 34 was added to the inlet ring 30 as shown in
In this manner, an amount of the ambient airflow impinging on the blade tips 36 is reduced thereby reducing the unwanted vibration and noise. While successful in reducing some of the noted adverse consequences by directing the portion of the ambient airflow past the blade tips 36, the air block 48 also created eddies of turbulent airflow both immediately downstream of the air block and at the inlet side of the blades 22, i.e., immediately downstream of the distal end 46. These eddies of turbulent airflow themselves create a new axial component of the airflow tending to impinge on the blade tips 36 causing airflow efficiency losses as well as additional potential for unwanted vibration and noise.
In order to further reduce the adverse consequences noted above, the inlet ring should be configured to reduce, if not eliminate, the high concentration of air adjacent the distal end of the labyrinth seal and to distribute the ambient airflow entering the housing more evenly over the length of the fan blades while avoiding the creation of turbulent airflow. More specifically, the inlet ring should be configured to be more efficient by providing an external surface along which ambient air can remain connected or attached for a longer period of time. The external surface should also provide smooth transitions for the air to adhere to in order to avoid creating eddies of turbulent air, and the distal end of the external surface (also known as the airflow separation point) should be located a greater distance from the fan blades than a distal end designed solely to act as part of the labyrinth seal.
In accordance with the purposes and benefits described herein, a blower assembly is provided. The blower assembly may be broadly described as including a housing having an air inlet side and a scrolled wall, a motor having an output shaft extending within the housing, and an airflow outlet. A wheel is mounted to the output shaft for rotation within the housing and has a plurality of blades for creating an airflow along the scrolled wall. An inlet ring extends from the air inlet side of the housing and includes a labyrinth seal portion to limit recirculation of air from the airflow. The labyrinth seal portion has an exterior surface along which ambient air entering the housing flows from a proximal end to a distal end, and a guide extends from the exterior surface downstream of the proximal end.
In one possible embodiment, the labyrinth seal portion is hook shaped. In another possible embodiment, the motor is positioned within the housing.
In one other possible embodiment, the guide extends from the distal end. In still another possible embodiment, the guide extends from the exterior surface along a portion of the inlet ring.
In one additional possible embodiment, the exterior surface of the labyrinth seal portion and an exterior surface of the guide form a smooth curve.
In accordance with an additional aspect, a blower assembly includes a housing having an air inlet side and a scrolled wall, a motor having an output shaft extending within the housing, a wheel mounted to the output shaft for rotation within the housing, the wheel having a plurality of blades for creating an airflow along the scrolled wall, an inlet ring supported by the air inlet side of the housing, the inlet ring having a labyrinth seal portion to limit recirculation of air from the airflow, the labyrinth seal portion having a first control surface along which ambient air entering the housing flows to a second control surface extending from the inlet ring for receiving and guiding the ambient air flow, and an airflow outlet.
In still another possible embodiment, the second control surface extends from the distal end. In one additional possible embodiment, the second control surface extends from the first control surface along a portion of the inlet ring.
In yet another possible embodiment, the first control surface and the second control surface form a smooth curve.
In other possible embodiments, the blower assemblies described above are incorporated into a vehicle.
In accordance with another aspect, a method of controlling air or other fluid entering a blower assembly is provided. The method may be broadly described as comprising the steps of: (a) creating an airflow using an impeller positioned within a housing having a scrolled wall; (b) sealing a first portion of the airflow within the housing; (c) guiding a second portion of the airflow outside of the housing using a first control surface along which the first portion of the airflow is drawn from a proximal end towards a distal end and a second control surface extending from the first control surface downstream of the proximal end; and (d) venting the first portion of the airflow.
In another possible embodiment, the first control surface forms part of an inlet ring supported by the housing.
In yet another possible embodiment, the inlet ring includes a labyrinth seal for sealing the first portion of the airflow within the housing.
In still another possible embodiment, the second control surface extends from the distal end of the first control surface. In another, the second control surface extends generally perpendicular to the first control surface at the distal end.
In yet one additional possible embodiment, the first control surface and the second control surface form a smooth curve.
In another possible embodiment, the first control surface forms part of an inlet ring. In still another, the inlet ring includes a labyrinth seal for sealing the first portion of the airflow within the housing.
In the following description, there are shown and described several preferred embodiments of the blower assembly and the related method. As it should be realized, the assemblies and methods are capable of other, different embodiments and their several details are capable of modification in various, obvious aspects all without departing from the assemblies and method as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The accompanying drawing figures incorporated herein and forming a part of the specification, illustrate several aspects of a blower assembly and together with the description serve to explain certain principles thereof. In the drawing figures:
Reference will now be made in detail to the present embodiments of the blower assembly and the related method, examples of which are illustrated in the accompanying drawing figures, wherein like numerals are used to represent like elements.
Reference is now made to
In operation, the motor 64 rotates output shaft 62 which in turn rotates the wheel 60 and a plurality of blades 66. Ambient air is drawn through an inlet of side wall 56 and across the plurality of blades 66 creating an airflow. The airflow includes an ambient airflow entering the housing 52 across an inlet ring 68 and an internal airflow (generally shown by arrows 70) within the housing. The internal airflow 70 travels from the blower wheel blades 66 through an air gap adjacent a scroll cut-off 72 within the airflow path. The internal airflow 70 continues around the scrolled wall 54 of the housing 52 before exiting the housing at an airflow outlet 74. The airflow outlet 74 may be attached to the housing 52, or may be integrally molded with the housing.
The presently described inlet ring 68 extends from or is otherwise attached to the housing 52 and may be integrally molded in one embodiment. The inlet ring 68, shown in cross section in
In an alternate embodiment shown in
In still another alternate embodiment shown in
In another aspect of the invention, a method of controlling an airflow entering a blower assembly 50 includes the steps of creating an airflow using wheel blades 66 positioned within a housing 52 having a scrolled wall 54, sealing a first portion of the airflow within the housing, and guiding a second portion of the airflow outside of the housing using a first control surface 80 along which the first portion of the airflow is drawn from a proximal end 82 towards a distal end 84 and a second control surface 86 extending from the first control surface downstream of the proximal end, and venting the first portion of the airflow.
As described in greater detail above, the airflow is created by driving the blades 66 with a motor 64 such that the blades rotate creating a flow of air within the housing 52. The first portion of the airflow is sealed within the housing by a labyrinth seal 76 forming a part of an inlet ring 68. The labyrinth seal 76 is shaped to the tips 78 of the blades 66. The first control surface 80 used to guide the second portion of the airflow from the proximal end 82 towards the distal end 84 forms a portion of the labyrinth seal 76 in the described embodiment. The second control surface 86 extends from the first control surface 80 downstream of the proximal end 82 and further guides the second portion of the airflow outside of the housing 52. In the described embodiments, the first control surface 80 forms part of the inlet ring 68 and the second control surface 86 extends from the distal end 84 of the first control surface. In the presently described embodiment, the second control surface 86 extends generally perpendicular to a distal portion of the first control surface 80. In an alternate embodiment reflected in
In summary, numerous benefits result from providing a blower assembly having an inlet ring configured to reduce, if not eliminate, the high concentration of air adjacent the distal end of the labyrinth seal and to distribute the ambient airflow entering the housing more evenly over the length of the fan blades while avoiding the creation of turbulent airflow. As shown, the inlet ring is configured to be more efficient by providing an external surface along which ambient air can remain connected or attached for a longer period of time. The external surface also provides smooth transitions for the air to adhere to in order to avoid creating eddies of turbulent air, and the distal end of the external surface (also known as the airflow separation point) is located a greater distance from the fan blades than a distal end designed solely to act as part of the labyrinth seal.
The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
