US2988266A - Self-cooled radial rotor - Google Patents

Description

June 13, 1961 J. w. HUGHES SELF-COOLED'RADIAL ROTOR 2 Sheets-Sheet 1 Filed Jan. 19, 1959 FIGS I O Y I Q; I /4 I I maria 1 5 and #1 WTNVENTOR 2 Sheets-Sheet 2 Filed Jan. 19, 1959 Fuel United States Patent G 2,988,266 SELF-COOLED RADIAL ROTOR John Wesley Hughes, Rte. 1, Box 92, Jamestown, N.C. Filed Jan. 19, 1959, Ser. No. 787,585 '5 Claims. (Cl. 230116) This invention relates to means for cooling the blades of the rotors in radial fluid machines that are exposed to the action of hot ,fiuids. Especially, it relates to means for cooling these blades where heat is a limiting factor. It is the prime objective of this invention to have the fluid that is cooling the aforementioned blades to be undergoing an essential acceleration at the same time that it is cooling the blades. In this manner, efficiency will be increased by the elimination of a cooling system whose mere function is to cool, while at the same time retaining the advantages of a cooling system.

Accordingly, I form the blades that are exposed to the action of the hot fluids in a manner such that their interiors are hollow and open to the back side, the back side being another radial fluid machine. Thus, the interiors of the hot blades function as passageways while cooling said blades.

These radial fluid machines are of three types: double turbine, turbine-compressor, and double compressor. To facilitate understanding, the embodiments shown are the combination turbine-compressor to show inward and outward flow in the same embodiment. The most familiar turbine-compressor is the gas turbine, and the specific embodiments illustrated are of this type. It is also in the gas turbine that heating is almost invariably critical.

The details of two embodiments of this invention are illustrated by the accompanying drawings, in which FIGURE 1 is a side elevation of a preferred embodiment of the invention with associated casing cut away on line 11 of FIGURE 2;

FIGURE 2 is a section on line 2.-.2 of FIGURE 1;

FIGURE 3 is a circular section on line 3-3 of FIG- URE 2;

FIGURE 4 is a circular section on line 4-4 of FIG- URE 2;

FIGURE 5 is an elevational view along line 55 of FIGURE 2;

FIGURE 6 is a side view of the rotor by itself;

FIGURE 7 is a circular section of a modification.

Referring to FIGURE 1, the rot-or 1 is shown together with auxiliary components to form a two-sided turbinecompressor. The turbine is indicated generally by the number 66, and the compressor is indicated generally by the number 67. The turbine side will hereafter be called the front side and the compressor side the back side. When the term gas turbine-compressor is used, reference is made to the entire machine. When the more specific terms of turbine or compressor are used, reference is made to the single section. The rotor 1 is fixed On a shaft 2 which rotates in bearings 3 and 4 in a clockwise direction with reference to FIGURE 2. The shaft 2 has a groove 5 in it. A rectangular pin 6 extends through the bearing 3 and into the groove 5, preventing lateral motion. The bearings 3 and 4 are supported by arms 7 and 71 which are attached to the back casing 8 and the front casing 99. Both casings are secured to a dividing plate 10 whose inside edge 11 is beveled to match the corresponding bevel of the rotors outside edge or rim 12, these bevels serving as a labyrinth impeding fiuid flow from one side to another.

The back casing 8 is composed of an inlet section 23 and a back rotor cover 24. The back casing 8 is so constructed that a back spiral passageway 13 is created near the outside of the rotor 1. Referring to FIGURE 2, the back spiral passageway 13 increases in cross-sectional Patented June 13, 1961 area, as it proceeds in a clockwise direction, from a very small width at 14 to a relatively large width at 15. Continuing in a clockwise direction, the back spiral passageway 13 connects to an expanding orifice 16.

The front casing 9 is composed of an outlet section 25 and a front rotor cover 26. The front casing 9 is so constructed that a front spiral passageway 17 is created near the outside of the rotor 1. Again with reference to FIGURE 2, the front spiral passageway 17 increases in cross-sectional area, as it proceeds in a counter-clockwise direction, from a small width at 18 to a relatively large width at 19. The width of the front spiral passageway 17 is shown in FIGURE 2 by the space between the rotor 1 and the dotted lines which represents where section line 2a2a crosses the front casing 9 in FIGURE 1. Continuing from 19 in a counterclockwise direction, the front spiral passageway 17 connects to a contracting inlet 20.

The zigzag construction of the rotor 1 is shown in FIGURES 3 and 4. It consists of a metallic or strength element 21 and a heat insulator 22 that is bonded to it. Near the shaft 2 the rotor 1 sharply zigzags, as FIGURE 3 shows; as it proceeds radially outward the amount of zigzag decreases, as shown in FIGURE 4, until at the outside edge 12 the rotor 1 is substantially flat. Thus an effective blading is produced on both sides of the rotor 1 by the zigzagging.

The operation proceeds as follows: Air from the atmosphere is drawn in between the arms 7 through the inlet section 23 of the back casing 8. The air then proceeds radially away from the shaft 2 through the back interstices 27 in the rotor 1, as shown by arrows 23. Here the air is accelerated in a clockwise direction by the rotation of the rotor 1. The air, which is relatively cool at this point, flows over the metallic element 21 of the rotor 1 and cools it. The air then flows into the back spiral passageway 13, where it proceeds along toward the expanding orifice 16, as shown by arrow 29. In

the back spiral passageway 13 the air is in a slightly com pressed condition. The air then proceeds through the expanding orifice 16 where it is further compressed by having part of its velocity energy converted into pressure energy.

The compressed air is then taken from the expanding orifice 16, by means not shown, and heated. One suitable means is a combustion chamber. Another is a gas envgine, in which case the gas turbine functions as a turbosupercharger.

The heated and compressed gas is fed into the coutracting inlet 20 from the heating means, by means not shown, where it is allowed to expand while gaining in velocity and decreasing in pressure. Then it travels around the contracting spiral of the front spiral passageway 17, as shown by arrow 30. The gas is forced to travel in toward the shaft 2, as shown by the arrows 50, in the front interstices 31 between the zigzags due to the contracting spiral; the hot gas, however, is kept physically separated from the cool air by the rotor 1. As it travels in toward the shaft 2 the hot gas decelerates in a clockwise direction and gives up its energy to the rotor -1. Although the gas at this point in the cycle is hot and would tend to weaken the metallic element 21 of the rotor 1 by heating it, the heat insulator element 22 of the rotor 1 along with the flow of the cool air on the metallic side 21 of the rotor 1 will counteract the heating effect of the hot gases and will keep the rotor 1 in a temperature range where it retains more of its strength. The addition of the heat insulator element 22 to the rotor 1 gives a marked decrease in the temperature of the rotor, because the relatively small amount of heat that does pass through the insulator has only a very short distance to travel across the narrow width of the metallic 3 element 21 of the rotor before it is conducted away by the cool air.

After the gas travels past the rotor 1, it passes out through the outlet section 25 to the atmosphere or to.- additional stages of turbines of the present type or other types which are not shown. If the present type of turbine is used for some of the additional stages, the compression of the air can be effected in stages to cool the rotor at each stage. These additional stages can be conveniently located on an extension of the same shaft. The excess energy can be taken from the shaft in a manner best suited for the particular use, the methods being so diverse and well known that no attempt will be made to show them.

Figure 7 shows a variation wherein a fin 32 is added to the metallic part 33 of the rotor 36. The front side of the rotor is covered by a heat insulator 34 which protects it from the hot gases which flow in the interstices 37. The fin 32 increases the area 35 wherein the cool air flows. This has the advantage of allowing the rotor more easily to compress a larger volume of air.

Althoughthe drawings in this patent make use of a zig-zag shape for the rotor, it is to be understood that the invention is not limited to this one illustrative type. On the contrary, the designer of an engine using the principles illustrated above is'left considerable latitude by way of modifying the strict zig-zag shape to achieve better streamlining and aerodynamic efficiency or altering the volume that each side of the rotor can handle.

I claim:

1. In a radial gas turbine-compressor, a radial rotor with a front side and a back side, the front side function-.

ing as a radial gas turbine rotor, the back side functioning as a radial compressor rotor, substantially radial blades on the front side and back side of the rotor, the

blades on the front side being folded, forming passageways open on the back side of the rotor, said passageways beginning and ending on the back side of the rotor a circular dividing rim, near the periphery of the rotor, separating the sides.

2. In a radial gas turbine-compressor, a rotor, as defined in claim 1, which has the front face of the rotor and the front blades covered with a heat insulator.

. 3. In a radial gas turbine-compressor, a rotor with blades on the front and back thereof, the blades on the front being folded forming passageways in their interiors, the passageways being open on the back side, the passageways serving as a part of the compressor and as a cooler for the front blades, the interior of the blades being closed to the front side, so that the components of the turbine rotor that are subjected to the heat of the hot gas are cooled on their opposite side by the flow of cold gas in the compressor side, all the components of the rotor being hollow, the hollow interiors of the blades. being open only on the compressor side, so that the in l teriors of the turbine blades are cooled by the cool air rotor coming together near the periphery to form a dividing rim.

4. In a radial gas turbine-compressor, a rotor, as de-. fined in claim 3, which has the front face of the rotor. and the front blades covered with a heat insulator.

5. A combination radial gas turbine-compressor com prised of: a two-sided radial rotor with radial blades onv both sides, one side functioning as an inward flow hot gas turbine rotor, the blades on the turbine side of the from the compressor side, the two sides of the rotor separate from one another so that all of the rotor that faces.

on the turbine side is adjacent to the compressor side,

the rotor coming together at its periphery to form a rim, a rotatable shaft that the rotor is mounted on, a two sided casing enclosing the rotor, a dividing plate separating the two sides of the casing, said dividing plate being in proximity on its inner edge with the outer edge of.

the rim of the rotor and each side of the casing being equipped with suitable inlet and outlet passageways.

References Cited in the file of this patent UNITED STATES PATENTS

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