MULTI-STAGE TURBINE USING STEEL AND ALUMINUM BLADES

Abstract

A multistage turbine having one or more input stage fan blades formed of aluminum and having one or more output stage fan blades formed of steel. One or more intermediate stages may be formed of aluminum or steel or a combination thereof.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a prior art HVLP turbine assembly in its housing.

FIG. 2 is a view of the prior art turbine assembly and housing of FIG. 1, shown partly in section.

FIG. 3 is an exploded view of the prior art turbine assembly of FIG. 2.

FIG. 4 is a side view of a turbine of the present invention, cut away to illustrate certain aspects of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the Figures, and most particularly to FIGS. 1-3, a prior art HVLP turbine assembly 10 and housing 11 may be seen. In apparatus 10, a single stage reverse axial flow turbine 40 is close coupled to a four stage conventional flow tangential discharge turbine 41. The arrangement shown in FIGS. 1-3 is from U.S. Pat. No. 5,639,222, the entire contents of which are hereby expressly incorporated by reference. As may readily be noted, apparatus 10 is capable of providing a five stage turbine, but requires two motors (46 and 47), and is generally less efficient and more costly than an integral five stage fan section driven by a single motor.

FIG. 4 shows an integral five stage turbine 200 illustrating the present invention. Turbine 200 has a fan stage 210 and an electric motor 212 coupled to the fan stage 210 to drive the fan stage 210 through rotation of a motor shaft 214. Shaft 214 is preferably supported by a motor bearing 216 and an intermediate bearing 218. The rotating fan blades in fan stage 210 are positioned outboard of the intermediate bearing 218 and thus constitute an overhung load on shaft 214.

The first and second stage fan blades 220 are preferably made of non-aircraft grade aluminum. The third stage fan blade may be made of non-aircraft grade aluminum (or steel if desired). The fourth and fifth stage fan blades 224 are preferably made of steel. It is to be understood that the present invention may be extended to turbines with more stages, for example, six stages.

In operation, cooling air for motor 212 is drawn in along arrow 226 via motor air intake 228. The motor cooling air exits motor 212 in the direction of arrows 230. Turbine air enters a fan stage inlet 232 indicated by arrow 234, and exits the fan stage 210 via a tangential exhaust 236, in the direction of arrow 238.

The invention may thus be seen to be a multistage turbine having at least one inlet stage fan blade formed of non-aircraft grade aluminum, and one or more intermediate stage fan blade formed of non-aircraft grade aluminum or steel (or a combination thereof), and one or more outlet stage fan blades formed of steel.

In a preferred embodiment, the invention is a five stage turbine having a first stage fan blade and a second stage fan blade each formed of non-aircraft grade aluminum, and a third stage fan blade formed of at least one of steel and non-aircraft grade aluminum, and a fourth stage fan blade and fifth stage fan blade formed of steel.

It is to be understood that the intermediate stage fan blade may be formed of both aluminum and steel, if desired, for its various components.

It is to be further understood that the present invention may be practiced using aircraft grade aluminum for some or all of the aluminum parts of the present invention, with the consequent reduction or elimination of the advantages of using non-aircraft grade aluminum.

The invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit and scope of the invention.

Claims

1. A multistage turbine having at least one inlet stage fan blade formed of aluminum, and an intermediate stage fan blade formed of one of the materials of aluminum and steel, and an outlet stage fan blade formed of steel.

2. The multistage turbine of claim 1 wherein the intermediate stage fan blade is formed of both aluminum and steel.

3. The multistage turbine of claim 1 wherein at least the one inlet stage fan blade is formed of non-aircraft grade aluminum.

4. The multistage turbine of claim 1 wherein the at least one inlet fan blade is formed entirely of aluminum.

5. The multistage turbine of claim 1 wherein the aluminum is non-aircraft grade aluminum.

6. A five stage turbine having a first stage fan blade and a second stage fan blade each formed of aluminum, and a third stage fan blade formed of at least one of steel and aluminum, and a fourth stage fan blade and fifth stage fan blade formed of steel.

7. The turbine of claim 6 wherein the third stage fan blade is formed of both aluminum and steel.

8. The turbine of claim 6 wherein at least the first and second stage fan blades are formed entirely of aluminum.

9. The turbine of claim 6 wherein the aluminum is non-aircraft grade aluminum.

10. The turbine of claim 6 wherein at least the first and second stage fan blades and the third stage fan blade are each formed of non-aircraft grade aluminum.

11. The turbine of claim 6 wherein each fan blade formed of aluminum is formed of non-aircraft grade aluminum.

12. A High Volume Low Pressure turbine assembly having five stages delivering air to a paint spray gun atomizing paint, the turbine assembly comprising: a) a plurality of inlet stage fan blades formed of non-aircraft grade aluminum; andb) at least one outlet stage fan blade formed of steel.

13. The turbine assembly of claim 12 further comprising at least one intermediate stage fan blade formed of one of non-aircraft grade aluminum and steel.

14. The turbine assembly of claim 12 further comprising at least one intermediate stage fan blade formed of both non-aircraft grade aluminum and steel.