JP2007211660A - Chip turbine fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip turbine fan capable of suppressing an excessive tensile stress generated at the end of each fan rotor blade while deformation of a shroud at the time of being driven is suppressed. <P>SOLUTION: The chip turbine fan is structured so that the ends of the fan rotor blades 5 are connected with the inside surface of the shroud 6 formed in a ring shape so as to be coaxial with the main shaft 4 while turbine rotor blades 7 are installed on the peripheral surface of the shroud 6, in which the shroud 6 is rotated by supplying gas to the turbine rotor blades 7, and thereby the fan rotor blades 5 are rotated, wherein the stiffness in the radial direction of the shroud 6 is made lower in the connection part with a relatively thin portion of each fan rotor blade 5 than in the connection part with a relatively thick portion of the fan rotor blade 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a chip turbine fan in which a shroud provided with turbine blades on the outer peripheral surface is installed on the outer periphery of a fan blade.

Patent Document 1 discloses a chip turbine fan in which a shroud provided with turbine blades on the outer peripheral surface is installed on the outer periphery of a fan blade. In this chip turbine fan, the end of the turbine rotor blade is connected to the inner peripheral surface of the shroud. Then, the shroud is rotated by supplying combustion gas to the turbine rotor blade, thereby rotating the fan rotor blade.
JP-A-5-164095 JP 2005-145264 A JP-A-10-501867

  In the tip turbine fan in which the turbine blade is provided on the outer peripheral surface of the shroud and the end of the turbine blade is connected to the inner peripheral surface of the shroud, the turbine blade, the shroud, and the fan blade rotate together. To do. In order to suppress the deformation of the shroud due to the centrifugal force generated at this time, it is necessary to increase the radial rigidity of the shroud to some extent.

  Also, the fan blades are pulled radially outward by the shroud due to the centrifugal force generated at this time. Therefore, a tensile stress is generated at the connection portion of the fan blade with the shroud. Here, in the fan rotor blade, the edge portion is relatively thin. For this reason, when a tensile stress is generated in the connection portion of the fan blade with the shroud, there is a possibility that a large tensile stress is generated near the edge of the end portion of the fan blade.

  The present invention has been made in view of the above problems, and in a chip turbine fan, it is possible to suppress the occurrence of excessive tensile stress at the end of the fan rotor blade while suppressing deformation of the shroud during driving. The problem is to provide a possible technology.

The chip turbine fan according to the present invention is
A fan portion having a main shaft and a fan rotor blade provided on the outer peripheral surface of the main shaft;
A tip turbine section having a shroud formed in an annular shape so as to be coaxial with the main shaft, and a turbine rotor blade provided on an outer peripheral surface of the shroud;
A gas supply unit for supplying gas to the turbine rotor blade,
The end of the fan rotor blade is connected to the inner peripheral surface of the shroud,
In the chip turbine fan that rotates the shroud by supplying gas to the turbine rotor blade by the gas supply unit, thereby rotating the fan rotor blade,
The radial rigidity of the shroud is lower at the connecting portion with the relatively thin portion of the fan rotor blade than at the connecting portion with the relatively thick portion of the fan rotor blade. It is characterized by that.

The greatest feature of the present invention is that the radial rigidity of the shroud is not uniform in the axial direction of the shroud. By reducing the radial rigidity of the shroud, it is possible to reduce the tensile stress generated at the end of the fan rotor blade when the chip turbine fan is driven. Further, when the radial rigidity of a part of the shroud in the axial direction is reduced, the tip turbine fan is driven more than when the radial rigidity of the entire shroud in the axial direction is uniformly reduced. The deformation of the shroud due to the centrifugal force can be suppressed.

  Therefore, according to the present invention, when the tip turbine fan is driven, it is possible to suppress excessive tensile stress from being generated at the end portion of the fan rotor blade while suppressing deformation of the shroud.

  According to the chip turbine fan of the present invention, it is possible to reduce the tensile stress generated in the vicinity of the edge of the end of the fan rotor blade while suppressing deformation of the shroud during driving.

  Hereinafter, specific embodiments of a chip turbine fan according to the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of a chip turbine fan according to the present embodiment. The chip turbine fan 1 includes a fan part 2 and a chip turbine part 3. The fan unit 2 includes a main shaft 4 and a plurality of fan rotor blades 5 provided on the outer peripheral surface of the main shaft 4. The tip turbine section 3 is formed in an annular shape so as to be coaxial with the main shaft 4 and is disposed on the outer periphery of the fan rotor blade 5, and a plurality of turbine rotor blades 7 provided on the outer peripheral surface of the shroud 6, have. In this embodiment, the end of the fan rotor blade 5 is connected to the inner peripheral surface of the shroud 6.

  A high-pressure gas supply port 9 is provided on the outer peripheral wall 8 formed so as to surround the outer periphery of the turbine rotor blade 7. High pressure gas is supplied to the high pressure gas supply port 9 from a gas tank (not shown).

  When driving the chip turbine fan 1, high-pressure gas is blown from the high-pressure gas supply port 9 to the turbine rotor blade 7. As a result, the shroud 6 rotates, whereby the fan rotor blade 5 rotates about the main shaft 4. In FIG. 1, the white arrow indicates the flow of high pressure gas, and the black arrow indicates the flow of air generated by the rotation of the fan rotor blade 5.

  Here, the cross-sectional shape of the fan rotor blade 5 will be described with reference to FIG. FIG. 2 is a diagram showing a cross-sectional shape of the fan rotor blade 5. In FIG. 2, black arrows indicate the air flow generated by the rotation of the fan rotor blade 5, as in FIG. 1. As shown in FIG. 2, in the fan rotor blade 5, the thickness in the vicinity of the edge (hereinafter referred to as the downstream edge) 5a on the downstream side along the air flow is smaller than that in the vicinity of the downstream edge 5a. The thickness of the portion (hereinafter simply referred to as the upstream portion) 5b on the upstream side along the air flow is thinner.

  When the fan blade 5 and the shroud 6 are rotated by driving the chip turbine fan 1, the fan blade 5 is pulled radially outward by the shroud 6 due to centrifugal force. Therefore, tensile stress is generated at the connection portion (end portion) of the fan rotor blade 5 with the shroud 6. At this time, since the thickness in the vicinity of the downstream edge 5a of the fan rotor blade 5 is thinner than the thickness of the upstream section 5b, the upstream section 5b is located in the vicinity of the downstream edge 5a at the end of the fan rotor blade 5. There is a possibility that a larger tensile stress may be generated.

Therefore, in the present embodiment, as shown in FIG. 1, the radial thickness ts of the shroud 6 is formed so as to become thinner toward the downstream side along the air flow. That is, shroud 6
The thickness of the portion connected to the vicinity of the downstream edge 5a of the fan rotor blade 5 is smaller than the thickness of the portion connected to the upstream portion 5b of the fan rotor blade 5.

  According to this, the radial rigidity of the shroud 6 is lower in the connection portion with the vicinity of the downstream edge 5a of the fan blade 5 than in the connection portion with the upstream portion 5b of the fan blade 5. As a result, when the chip turbine fan 1 is driven, the tensile stress generated in the vicinity of the downstream edge 5a at the end of the fan rotor blade 5 can be reduced.

  In addition, when the shroud 6 is formed as described above, the width ts of the shroud 6 is uniformly reduced in the axial direction to the width of the portion connected to the vicinity of the downstream edge 5 a of the fan rotor blade 5. A decrease in the rigidity of the shroud 6 as a whole can be suppressed.

  Therefore, according to this embodiment, when the chip turbine fan 1 is driven, it is possible to suppress the occurrence of excessive tensile stress at the end of the fan rotor blade 5 while suppressing the deformation of the shroud 6.

<Modification 1>
Here, a first modification of the present embodiment will be described with reference to FIG. FIG. 3 is a view showing a cross-sectional shape of the shroud 6 according to the first modification. In FIG. 3, black arrows indicate the flow of air generated by the rotation of the fan rotor blade 5, as in FIG. 1.

  As shown in FIG. 2, in the fan rotor blade 5, the thickness near the edge on the upstream side is also thinner than that near the center of the fan rotor blade 5. Therefore, in the first modified example, as shown in FIG. 3, the edge of the shroud 6 on the upstream side of the fan blade 5 (hereinafter referred to as the thickness of the portion connected to the vicinity of the center of the fan blade 5) The thickness of the portion connected to the vicinity (referred to as upstream edge) is reduced.

  Thereby, not only the downstream edge of the end portion of the fan rotor blade 5 but also the tensile stress generated in the vicinity of the upstream edge can be reduced. Therefore, it is possible to further suppress the occurrence of excessive tensile stress at the end portion of the fan rotor blade 5 when the chip turbine fan 1 is driven.

  In the present embodiment, as shown in FIG. 4, fillets 10 may be provided on the upstream edge and the downstream edge of the end portion of the fan rotor blade 5. In this case, the tensile stress generated in the fillet 10 when the chip turbine fan 1 is driven tends to increase. However, even in such a case, it is possible to suppress an excessive increase in the tensile stress generated in the fillet 10 by forming the shroud 6 as in the first modification.

<Modification 2>
Next, a second modification of the present embodiment will be described with reference to FIG. (A) of FIG. 5 is a figure which shows the cross-sectional shape of the shroud 6 which concerns on this 2nd modification. FIG. 5B is a view showing a state of the inner peripheral surface of the shroud 6 according to the second modification. In FIG. 5, black arrows indicate the flow of air generated by the rotation of the fan rotor blade 5 as in FIG. 1.

  In the second embodiment, as shown in FIG. 5, the radial thickness ts of the shroud 6 is the same on the upstream side and the downstream side along the air flow. And the recessed part 11 is formed between the connection part of the fan rotor blade 5 in the shroud 6 and a connection part.

As shown in FIG. 5A, the bottom surface of the recess 11 is formed obliquely with respect to the inner peripheral surface of the shroud 6. The recess 11 is deepest at a position equivalent to a portion where the vicinity of the downstream edge 5a of the end of the fan rotor blade 5 is connected in the axial direction of the shroud 6.

  By forming the concave portion 11 in the shroud 6 as described above, the radial rigidity of the shroud 6 can be made downstream of the fan blade 5 compared to the connection portion with the upstream portion 5b of the fan blade 5 in the same manner as described above. It can be made lower at the connection portion with the vicinity of the edge 5a. Therefore, when the chip turbine fan 1 is driven, the tensile stress generated in the vicinity of the downstream edge 5a at the end of the fan rotor blade 5 can be reduced.

  In the second modification, the recess 11 may be provided on the outer peripheral surface of the shroud 6.

<Modification 3>
Next, a third modification of the present embodiment will be described with reference to FIG. FIG. 6 is a view showing a cross-sectional shape of the shroud 6 according to the third modification. In FIG. 6, black arrows indicate the flow of air generated by the rotation of the fan rotor blade 5, as in FIG. 1.

  In the third embodiment, as shown in FIG. 6, the radial thickness ts of the shroud 6 is the same on the upstream side and the downstream side along the air flow. And the groove | channel 12 is formed in the end surface of a downstream side along the flow of the air of the shroud 6. FIG. The bottom surface of the groove 12 is in the same position as the portion where the vicinity of the downstream edge 5 a of the end of the fan rotor blade 5 is connected in the axial direction of the shroud 6.

  By forming the groove 12 in the shroud 6 as described above, the radial rigidity of the shroud 6 is made downstream of the fan rotor blade 5 compared to the connection portion with the upstream portion 5b of the fan rotor blade 5 as described above. It can be made lower at the connection portion with the vicinity of the edge 5a. Therefore, when the chip turbine fan 1 is driven, the tensile stress generated in the vicinity of the downstream edge 5a at the end of the fan rotor blade 5 can be reduced.

  The embodiments described above can be combined as much as possible.

1 is a cross-sectional view illustrating a schematic configuration of a chip turbine fan according to a first embodiment. The figure which shows the cross-sectional shape of a fan rotor blade. The figure which shows the cross-sectional shape of the shroud which concerns on the 1st modification of Example 1. FIG. The figure which shows the mode of the connection part of a fan rotor blade and a shroud at the time of providing the fillet in the upstream edge and downstream edge of the edge part of a fan rotor blade in the 1st modification of Example 1. FIG. FIG. 5A is a diagram illustrating a cross-sectional shape of the shroud according to the second modification of the first embodiment. FIG. 5B is a diagram illustrating a state of the inner peripheral surface of the shroud according to the second modification of the first embodiment. The figure which shows the cross-sectional shape of the shroud which concerns on the 3rd modification of Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chip turbine fan 2 ... Fan part 3 ... Chip turbine part 4 ... Main shaft 5 ... Fan blade 5a .. Downstream edge 5b ... Upstream part 6 ... Shroud 7 ..Turbine blade 8 ... outer peripheral wall 9 ... high pressure gas supply port 10 ... fillet 11 ... recess 12 ... groove

Claims (1)

A fan portion having a main shaft and a fan rotor blade provided on the outer peripheral surface of the main shaft;
A tip turbine section having a shroud formed in an annular shape so as to be coaxial with the main shaft, and a turbine rotor blade provided on an outer peripheral surface of the shroud;
A gas supply unit for supplying gas to the turbine rotor blade,
The end of the fan rotor blade is connected to the inner peripheral surface of the shroud,
In the chip turbine fan that rotates the shroud by supplying gas to the turbine rotor blade by the gas supply unit, thereby rotating the fan rotor blade,
The radial rigidity of the shroud is lower at the connecting portion with the relatively thin portion of the fan rotor blade than at the connecting portion with the relatively thick portion of the fan rotor blade. A chip turbine fan characterized by that.

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