US-20260126053-A1 - VANEAXIAL BLOWER SYSTEM INCLUDING ROTOR FAN HAVING CURVED BLADES

US20260126053A1US 20260126053 A1US20260126053 A1US 20260126053A1US-20260126053-A1

Abstract

A vaneaxial blower system has an axis of rotation and includes a rotor fan including a hub, a rotor inlet, a rotor outlet, and rotor blades. Each rotor blade has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end. The tip width is larger than the hub width. The trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape.

Inventors

Pritesh Mandal
Saigeetha Padiri

Assignees

REGAL BELOIT AMERICA, INC.

Dates

Publication Date: 20260507
Application Date: 20241105

Claims (20)

1 . A vaneaxial blower system having an axis of rotation, the vaneaxial blower system comprising: a rotor fan including a hub, a rotor inlet, a rotor outlet, and rotor blades, wherein each rotor blade of the rotor blades has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end; a rotor shroud extending around the rotor fan, the rotor shroud including a rim and a flared inlet section extending from the rim, the rim and the flared inlet section defining the rotor inlet of the rotor fan; and a stator including a stator inlet, a stator outlet, and stator blades, wherein the stator blades are positioned downstream from the rotor blades, wherein each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end, and wherein the tip width is larger than the hub width, and wherein the trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape, the concave portion extending from the tip end to the convex portion, the convex portion extending from the concave portion to the hub end, and wherein an angle beta is defined as a slope of a camber line at a location along a span of a first rotor blade of the rotor blades, the angle beta includes: a first range for the leading edge and a second range for the trailing edge at the hub, a third range for the leading edge and a fourth range for the trailing edge at the tip end, and fifth range for the leading edge and a sixth range for the trailing edge at a midpoint along the span of the first rotor blade, between the hub and the tip end, wherein the first range, the second range, the third range, the fourth range, the fifth range, and the sixth range are selected to reduce flow separation along a blade span of each rotor blade, thereby mitigating stall conditions of the vaneaxial blower system.
2 . The vaneaxial blower system of claim 1 , wherein the concave portion has a first radius and the convex portion has a second radius, wherein the first radius is different from the second radius.
3 . (canceled)
4 . The vaneaxial blower system of claim 1 , wherein the leading edge is curved and has a radius.
5 . The vaneaxial blower system of claim 4 , wherein the radius changes along the extension of the leading edge.
6 . The vaneaxial blower system of claim 4 , wherein the leading edge is concave.
7 . The vaneaxial blower system of claim 1 , wherein the tip end includes a tip edge extending from the leading edge to the trailing edge, and wherein the tip edge is curved and has a radius.
8 . The vaneaxial blower system of claim 7 , wherein the radius of the tip edge changes along the extension of the tip edge.
9 . The vaneaxial blower system of claim 1 , wherein the stator inlet is arranged to receive airflow discharged from the rotor outlet.
10 . The vaneaxial blower system of claim 1 , wherein at the hub, the first range of the angle beta for the leading edge is in the range of 70 degrees to 80 degrees and the second range of the angle beta for the trailing edge is in the range of 25 degrees to 35 degrees; wherein at the tip end, the third range the angle beta for the leading edge is in the range of 80 degrees to 90 degrees and the fourth range of the angle beta for the trailing edge is in the range of 60 degrees to 70 degrees, and wherein at the midpoint, the fifth range of the angle beta for the leading edge is in the range of 70 degrees to 80 degrees and the sixth range of the angle beta for the trailing edge is in the range of 55 degrees to 70 degrees.
11 . (canceled)
12 . A rotor fan for a vaneaxial blower system having an axis of rotation, the rotor fan comprising: a hub; a rotor inlet at least partially defined by a rotor shroud surrounding the rotor fan; a cone coupled to the hub and extending axially from the hub adjacent the rotor inlet, the cone extending axially beyond the rotor shroud; a rotor outlet axially opposite the rotor inlet; and rotor blades, wherein each rotor blade of the rotor blades has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end, wherein each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end, and wherein the tip width is larger than the hub width, wherein the trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape, the concave portion extending from the tip end to the convex portion, the convex portion extending from the concave portion to the hub end, and wherein an angle beta is defined as a slope of a camber line at a location along a span of a first rotor blade of the rotor blades, the angle beta includes: a first range for the leading edge and a second range for the trailing edge at the hub, a third range for the leading edge and a fourth range for the trailing edge at the tip end, and fifth range for the leading edge and a sixth range for the trailing edge at a midpoint along the span of the first rotor blade, between the hub and the tip end, wherein the first range, the second range, the third range, the fourth range, the fifth range, and the sixth range are selected to reduce flow separation along a blade span of each rotor blade, thereby mitigating stall conditions of the vaneaxial blower system.
13 . The rotor fan of claim 12 , wherein the concave portion has a first radius and the convex portion has a second radius, wherein the first radius is different from the second radius.
14 . The rotor fan of claim 12 , wherein the leading edge has a concave curve.
15 . The rotor fan of claim 12 , wherein the tip end includes a tip edge extending from the leading edge to the trailing edge, and wherein the tip edge is curved and has a radius.
16 . The rotor fan of claim 12 , wherein at the hub, the angle beta for the leading edge is in the range of 70 degrees to 80 degrees and the angle beta for the trailing edge is in the range of 25 degrees to 35 degrees; and wherein at the tip end, the angle beta for the leading edge is in the range of 80 degrees to degrees and the angle beta for the trailing edge is in the range of 60 degrees to 70 degrees.
17 . The rotor fan of claim 16 , wherein at a span half a distance from the hub end to the tip end, the angle beta for the leading edge is in the range of 70 degrees to 80 degrees and the angle beta for the trailing edge is in the range of 55 degrees to 70 degrees.
18 . (canceled)
19 . A method of assembling a vaneaxial blower system having an axis of rotation, the method comprising: coupling a rotor fan to a stator such that the stator is positioned downstream from the rotor fan, the rotor fan includes a hub, a rotor inlet, a rotor outlet, rotor blades, and a rotor shroud extending around the hub and the rotor blades, wherein the rotor shroud includes a rim and a flared inlet section extending from the rim, the rim and the flared inlet section defining the rotor inlet of the rotor fan; and positioning the rotor blades around the hub such that the rotor fan rotates around the axis of rotation and directs airflow toward stator blades of the stator, wherein each rotor blade of the rotor blades has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end, wherein each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end, and wherein the tip width is larger than the hub width, wherein the trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape, the concave portion extending from the tip end to the convex portion, the convex portion extending from the concave portion to the hub end, and wherein an angle beta is defined as a slope of a camber line at a location along a span of a first rotor blade of the rotor blades, the angle beta includes: a first range for the leading edge and a second range for the trailing edge at the hub, a third range for the leading edge and a fourth range for the trailing edge at the tip end, and fifth range for the leading edge and a sixth range for the trailing edge at a midpoint along the span of the first rotor blade, between the hub and the tip end, wherein the first range, the second range, the third range, the fourth range, the fifth range, and the sixth range are selected to reduce flow separation along a blade span of each rotor blade, thereby mitigating stall conditions of the vaneaxial blower system.
20 . The method of claim 19 , further comprising fabricating a first rotor blade of the rotor blades, wherein at the hub, the angle beta for the leading edge is in the range of 70 degrees to 80 degrees and the angle beta for the trailing edge is in the range of 25 degrees to 35 degrees, and wherein at the tip end, the angle beta for the leading edge is in the range of 80 degrees to 90 degrees and the angle beta for the trailing edge is in the range of 60 degrees to 70 degrees.

Description

TECHNICAL FIELD The field of the disclosure relates generally to a vaneaxial blower system including a rotor fan having curved blades. BACKGROUND OF INVENTION Blowers are commonly used in the heating, ventilation, and air conditioning (HVAC) industries for moving indoor air. In a known blower, air is drawn into the indoor air moving system and then forced out an outlet into the indoor space. Known blowers include an impeller or fan to move the air through the outlet into the indoor space. The efficiency of a blower when moving high-pressure air can be increased by using a vaneaxial fan, the vaneaxial fan improving the movement of air in the axial direction out the outlet via guide vanes. Axial fans can experience stall conditions when the static pressure rise across fan blades reaches the fan operating static pressure developing limit, resulting in a reduction of flow velocity though the fan beyond a level at which the flow velocity initially falls to zero and subsequently reverses. As flow velocity reverses, it causes separation of air from the fan blades resulting in air turbulence with the separated air flow buffeting the fan blades. This aerodynamic instability induces stress within the blades that can result in mechanical failure of the fan motor, which otherwise requires balance across the fan blades to operate efficiently. To mitigate stall conditions, axial fans are conventionally oversized relative to the required specifications of a given application, which is not economical. Therefore, there is a need in the art to provide vaneaxial blower systems that can improve laminar flow, improve the static pressure profile of the blower, and reduce turbulence of the fan blades. BRIEF DESCRIPTION In one aspect, a vaneaxial blower system has an axis of rotation and includes a rotor fan and a stator. The rotor fan includes a hub, a rotor inlet, a rotor outlet, and rotor blades. Each rotor blade of the rotor blades has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. The stator includes a stator inlet, a stator outlet, and stator blades. The stator blades are positioned downstream from the rotor blades. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end. The tip width is larger than the hub width. The trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape. The concave portion extends from the tip end to the convex portion. The convex portion extends from the concave portion to the hub end. In another aspect, a rotor fan for a vaneaxial blower system has an axis of rotation, and includes a hub, a rotor inlet, a rotor outlet, and rotor blades. Each rotor blade of the rotor blades has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end. The tip width is larger than the hub width. The trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape. The concave portion extends from the tip end to the convex portion. The convex portion extends from the concave portion to the hub end. In yet another aspect, a method of assembling a vaneaxial blower system having an axis of rotation includes coupling a rotor fan to a stator such that the stator is positioned downstream from the rotor fan. The rotor fan includes a hub, a rotor inlet, a rotor outlet, and rotor blades. The method also includes positioning the rotor blades around the hub such that the rotor fan rotates around the axis of rotation and directs airflow toward stator blades of the stator. Each rotor blade of the rotor blades has a hub end coupled to the hub, a tip end opposite the hub end, a leading edge extending between the hub end and the tip end, and a trailing edge extending between the hub end and the tip end. Each rotor blade has a hub width between the trailing edge and the leading edge at the hub end, and a tip width between the trailing edge and the leading edge at the tip end. The tip width is larger than the hub width. The trailing edge of each rotor blade includes a concave portion and a convex portion forming an S-shape. The concave portion extends from the tip end to the convex portion. The convex portion extends from the concave portion to the hub end. These and other aspects and features of the present disclosure will be more readily understood when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of an example vaneaxial blower system,