JPH018643Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radial turbine rotor, and particularly to a ceramic radial turbine rotor used in a gas turbine or a turbocharger.

Turbine rotors that are supplied with high-temperature gas and are required to rotate at high speeds under high temperature conditions must be able to withstand these harsh conditions. Recently, ceramic turbine rotors with particularly excellent heat resistance have been developed in response to the is required.

Figures 1A and 1B and Figures 2A and 2B respectively show examples of this type of turbine rotor.
56-52914), the back plate 2 of the turbine rotor 1 is located between the blade tips 3 between adjacent turbine blades 3.
It is formed by being recessed in the radial direction from the outer circumferential circle 4 where A is arranged. Note that here, 3B is the discharge side end of the blade 3, and 1A is the disk portion of the rotor 1.

That is, in the case of the ceramic turbine rotor 1 formed into such a shape, by recessing the portion between the blades of the back plate 2, weight reduction is achieved, improving rotational performance and reducing centrifugal stress. can be expected to have a reducing effect.

Examples of Figure 2A and Figure 2B (Patent Application 1983-
123783) is an example in which the back plate 2 is formed to extend to the line of the outer circumferential circle 4 even between adjacent turbine blades 3. In this example, the blade tip 3A and the back plate 2 are connected to the blade tip 3.
A sufficient bonded state can also be maintained at position A.

Ceramic turbine rotor 1 having such a configuration
In this case, the wing tip 3A is connected to the back plate 2 as described above.
Since it is maintained in a sufficiently strongly reinforced state by the blade tip 3A, the impact resistance is increased against damage caused by the collision of the lining insulation material and separated combustion products that fly from upstream near the blade tip 3A. Can be done.
However, in the case of the ceramic turbine rotor 1 of the type shown in FIGS. 1A and 1B, the blade tips 3A are maintained in a state protruding from the back plate 2. As in the example shown in Figure 2B, the wing tip 3A is not reinforced by the back plate 2, and therefore, the tip of the wing 3, that is, the back plate 2 and the wing, may be damaged by the collision of foreign objects flying from upstream. The tip of the blade 1 beyond the part 5 (hereinafter referred to as the joint part) where the connection with the blade 3 is obtained is damaged.

On the other hand, in the case of the ceramic turbine rotor of the type shown in FIGS. 2A and 2B, although impact resistance against flying foreign objects can be obtained, the centrifugal stress in the center 6 of the disk 1A increases accordingly. Therefore, there is a possibility that damage may occur from the vicinity of the center portion 6. In particular, in the case of the examples shown in FIGS. 1A and 1B, when the ceramic turbine rotor 1 is injection molded, the joint 5 between the blade tip and the back plate 2 is removed during mold release or sintering. There was a problem that cracks were likely to occur in the vicinity due to the shape.

In view of these problems, the purpose of this invention is to
It is an object of the present invention to provide a radial turbine rotor capable of suppressing an increase in centrifugal stress while increasing impact resistance against flying foreign matter.

In order to achieve such an objective, the present invention provides a radial turbine rotor in which the back plate of the turbine extends in the radial direction to the blade tip position, and the back plate has a circumferential width only near the blade tip position. The back plate and the tip of the wing are connected in a substantially T-shape, and the back plate is recessed in the radial direction at the position between adjacent wings. This is a characteristic feature.

The present invention will be described below with reference to the drawings.

3A and 3B show an embodiment of the present invention, in which a back plate 2 extending in the radial direction to the position of the outer circumferential circle 4 where the blade tip 3A is arranged and the blade tip are connected. Thus, the width of the back plate 2 in the circumferential direction is maintained at the blade tip 3A. Thus, back plate 2 and wing 3
As shown in FIG. Or make it continuous with a cubic curve.

The configuration is the same as in FIGS. 1A and 1B except that the back plate 2 between the blades remote from the position of the blade tip 3A is constricted in the radial direction to form a recess 8.

In the ceramic radial turbine rotor 11 formed in this way, the blade 3 including the blade tip 3A is
Since the tip of the back plate 2 is reinforced by the extended back plate 2, the rigidity of this part is increased, which not only increases the impact resistance against flying foreign objects but also maintains the continuity of the shape. This prevents cracks that tend to occur during injection molding and sintering.

Furthermore, by forming the recess 8 in the back plate 2 between the blades, the centrifugal stress generated in the disk center 6 can be kept low, making it possible to rotate at high speed, and the moment of inertia can be reduced to Figure 2A
And since it is smaller than the case of FIG. 2B, the turbine acceleration performance can be improved.

As explained above, according to the present invention, the back plate near the tip of each turbine blade is made to extend in the radial direction while maintaining the width in the circumferential direction up to the position of the blade tip, and the back plate and the tip of the blade are In addition to connecting the parts in a substantially T-shape,
The back plate between the blades is recessed in the radial direction from the outer circumference, increasing the rigidity of this area and increasing the impact resistance against foreign objects flying in the gas, preventing damage. In this case, the back plate was formed to be recessed inward from the outer circumferential circle where the wing tips are placed, so
The centrifugal stress at the center of the disk can be reduced by this reduced mass, and the moment of inertia is also reduced, which not only makes it possible to handle high rotations but also improves the acceleration performance of the turbine.

Furthermore, if the blade is made of ceramic, it is possible to prevent cracks from forming at the connection between the blade tip and the back plate during injection molding or sintering.

[Brief explanation of the drawing]

FIG. 1A and FIG. 2A are front views showing an example of the form of a conventional radial turbine rotor, respectively;
Figures 1B and 2B are a sectional view taken along the line A-A of Figure 1A, a sectional view taken along the line B-B of Figure 2A, and Figure 3A.
3 is a front view showing an example of the form of the radial turbine rotor of the present invention, FIG. 3B is a sectional view taken along the line CC in FIG. 3A, and FIG. 3C is a sectional view taken along the line DD in FIG. 3A. . 1... Turbine rotor, 1A... Disk part, 2...
Back plate, 3... wing, 3A... wing tip, 3B... end, 4...
Outer circumference circle, 5...joint part, 6...center part, 7...connection part,
8... Concavity, 11... Turbine rotor.

Claims (1)

[Scope of utility model registration request] In a radial turbine rotor in which the back plate of the turbine extends in the radial direction to the tip position of the blade, the back plate extends while maintaining the width in the circumferential direction only in the vicinity of the tip position of the blade, and the back plate and the tips of the blades are connected in a substantially T-shape, and the back plate is recessed in the radial direction at a position between adjacent blades among the blades. Rotor.