Blower Apparatus and Method for Packaged Terminal Air Conditioner

Abstract

A blower apparatus designed for PTAC use includes an impeller configured to be capable of rotating about a central axis; a low voltage DC motor arranged to drive the impeller; a housing configured to accommodate the motor and impeller fixed together; an inlet cover which draws fresh air into the apparatus and an outlet port that discharges the fresh air through an outlet port and at least two directional changes perpendicular to the flow of fresh air through the inlet.

Description

FIELD OF THE INVENTION

This invention relates to a blower apparatus and method useful in a packaged terminal air conditioner (PTAC). The subject blower apparatus draws fresh air from the outdoor environment to be pretreated, pressurized, and then discharged into an air distribution system that combines the pretreated, pressurized fresh air with air being recirculated inside an identified space in which the indoor section of the PTAC is installed in accordance with applicable building codes and regulations.

DESCRIPTION OF RELATED ART

Air conditioner systems, apparatus, methods and designs are disclosed in at least the following United States patents and publications: U.S. Pat. Nos. 3,666,002; 5,992,160; 6,009,716; 7,628,026; 8,757,506; 9,383,115; 9,696,044; D618,777; 2005/0224591; and 2008/0230619.

SUMMARY OF THE INVENTION

A centrifugal blower apparatus designed for use in a PTAC includes an impeller with inclined fins or vanes configured to be rotated about a central axis; a low voltage DC motor arranged to drive the impeller; a housing configured to accommodate the motor and impeller fixed together; an inlet through which pretreated fresh air is drawn into the blower apparatus and an outlet through which the pretreated fresh air is discharged through two perpendicular bends and then combined with inside air being recirculated by the PTAC.

The blower apparatus is constructed to draw fresh air from the external environment to the indoor enclosure for PTAC Series in accordance with known building code regulations. This blower apparatus arranges to draw fresh air in from one side and discharge it perpendicularly upward relative to the inlet port. The low voltage DC motor rotates the impeller to create suction to draw pretreated fresh air in and then pressurize and expel the pressurized fresh air out through the outlet port to be combined with the inside air being recirculated by the PTAC. The housing provides an accommodation for the impeller to concentrate the drawn in sir and expel it out through the outlet port. The cover acts as an inlet guide to draw fresh air into the suction side of the impeller.

This blower apparatus can also be used with appropriate modifications in other types of air-conditioners.

BRIEF DESCRIPTION OF THE DRAWINGS

The apparatus of the invention is further described and explained in relation to the following drawings wherein:

FIG. 1 is a rear perspective of one embodiment of the blower apparatus of the invention;

FIG. 2 is a side elevation view, partially broken away, of the housing of the blower apparatus of FIG. 1 with the cover and impeller removed;

FIG. 3 is a side elevation view, partially broken away, of the housing of the blower apparatus of FIG. 1 with the impeller installed and the cover removed;

FIG. 4 is a top plan view of the blower apparatus of FIG. 1; and

FIG. 5 is a cross-sectional top plan view taken through the impeller shaft of the blower apparatus of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the accompanying drawings, FIG. 1 illustrates a perspective view of one embodiment of the invention in which blower apparatus 10 embodies housing 1, impeller 2, and inlet cover 3.

FIG 5. further illustrates stainless steel shaft 4, durable self-lubricating ball bearings 5, self-adjusting load spring 6, low voltage DC motor 7 operatively connected to a feedback control loop circuit.

When impeller 2 rotates around the horizontal axis of shaft 4, fresh air is sucked in from the side and is discharged from the top. The impeller is driven by a low voltage DC motor to create the rotational action which sucks fresh air in from the outside and discharge it through the discharge port to be combined with inside air being recirculated through the PTAC.

Referring to FIGS. 2 and 5, the angle of the central vertical axis through shaft 4 in relation to the outlet port is desirably in the range of 4-6 degree, which is designated by the value “X” in FIG. 2.

Housing 1, when coupled with impeller 2, creates a scroll which generates the needed pressure to drive the fresh air out the discharge port. This scroll configuration is based on the reduction of space between the housing inner walls and the impeller external surface. The ratio of reduction is preferably about 4.2:1, which is shown in FIG. 3 as dimension Z1/Z2.

The central location of impeller 2 in reference to the air outlet port is of equal distance between the housing against impeller and impeller against the air inlet cover. FIG. 4, dimension Y.

The fins or vanes of impeller are equally spaced from the impeller center main rib. These air moving fins number 47 per side. The crescent shaped air moving fins height is ratio at 1/10 the size of the impeller diameter. See FIG. 3, dimension W1/W2.

Referring again to FIG. 1, housing 1, impeller 2 and cover 3 of blower apparatus 10 are desirably made of durable, heat resistant, anti-microbial rated plastic. The low voltage DC driven motor 7 is desirably provided with a feedback loop circuit to provide a constant rotation for the impeller, which in turn generates a constant airflow out of blower apparatus 10. Self-lubricating ball bearings 5 act as pivot points for the impeller to maintain a stable low vibration rotation, which also contributes to low operational noise levels. The self-adjusting load spring 6 maintains impeller 2 in its centralized location to ensure smooth rotation and proper balance during use.

The stainless steel shaft 4 is desirably integrated with impeller 2 during plastic injection to ensure properly secured, durable operation. The structural strength of impeller 2 is centered in the middle with the air moving fins extending from both sides to create a good balancing for impeller 2 during operation. With proper balance, there is little vibration and thus a low noise operation for blower apparatus 10.

Low voltage motor 7 desirably runs at 24V DC, a non-life threatening voltage, to provide electrical safety to users during operation of the PTAC. The two small holes 101 on impeller 7 act as shipping locks when a pin is inserted into it as shown in FIG. 1. Rectangular slots 102 (FIG. 2) on the lower section of housing 1 act as drainage holes if water enters blower apparatus 10.

Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading this specification in view of the accompanying drawings, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.

Claims

1. A blower apparatus for use in a packaged terminal air conditioner, the blower apparatus comprising housing, impeller, inlet cover, stainless steel shaft, self-lubricating ball bearings, self-adjusting load spring, and a low voltage DC motor operatively connected to a feedback control loop circuit.

2. The blower apparatus of claim 1 wherein the impeller rotates around the axis of the shaft and is driven by the low voltage DC motor.

3. The blower apparatus of claim 1 wherein the angle of the central vertical axis through the shaft relative to the outlet port ranges from 4-6 degrees.

4. The blower apparatus of claim 1 wherein the housing, when coupled with impeller, creates a scroll which pressurizes the fresh air to drive the fresh air out the outlet port.

5. The blower apparatus of claim 4 wherein the scroll configuration is based on the reduction of space between the housing inner walls and the impeller external surface.

6. The blower apparatus of claim 5 wherein the ratio of reduction is preferably about 4.2:1.

7. The blower apparatus of claim 1 wherein the impeller is centered between the housing and the air inlet cover.

8. The blower apparatus of claim 1 wherein the impeller has equally spaced fins or vanes equally spaced between the impeller center and the housing.

9. The blower apparatus of claim 1 wherein the impeller has 47 fins or vanes per side.

10. The blower apparatus of claim 1 wherein the ratio of fin height to impeller diameter is about 1:10.

11. A method for drawing fresh air into a pressurized terminal air conditioner (PTAC) comprising providing a fresh air inlet port configured to receive fresh (outside) air, providing a centrifugal blower apparatus disposed in fluid communication with the fresh air inlet port, operating the centrifugal blower apparatus to draw fresh air into an impeller disposed that pressurizes and then redirects and discharges the pressurized air perpendicularly to the incoming air and upwardly from the blower apparatus into a receiving duct that redirects a flow of pressurized fresh air to be combined with a flow of inside air being recirculated by the PTAC.