Radial turbine blade

Patent metadata

Field	Value
Publication number	US-9777578-B2
Application number	US-201214655296-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Dec 27, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

An object is to provide a radial turbine blade that can reduce an impact loss of inflowing gas at a leading edge of the turbine blade and achieve a higher turbine efficiency, even in a case of a flow field corresponding to a low turbine operational velocity ratio U/C0 due to a throttling operation on a variable nozzle mechanism of a variable geometry turbocharger.
In a radial turbine blade, a hub-side end portion Pa at a leading edge 51 of a turbine blade 50 is formed to be positioned more on a rear side in a rotation direction R of the turbine blade 50 than a shroud-side end portion Sc at the leading edge 51 , and a straight line connecting between the shroud-side end portion Sc and the hub-side end portion Pa is inclined with respect to a straight line extending in a rotation axis direction from the shroud-side end portion Sc at the leading edge 51 onto a hub 17 surface by an angle in a range from 30° to 70° as viewed in the radial direction of the turbine blade 50.

First claim

The invention claimed is:

1. A radial turbine blade configured to drivingly rotate a turbine rotor with working gas flowing in a radial direction from a spiral scroll formed in a turbine casing to a turbine blade of the turbine rotor positioned on an inner side of the scroll to act on the turbine blade and then flowing out in an axial direction, comprising a variable nozzle mechanism in which a plurality of nozzle vanes are disposed at an equal interval along a circumferential direction of a turbine on an inner circumference side of the scroll, and a blade angle of the nozzle vanes is changed, wherein
a hub-side end portion at a leading edge of the turbine blade and on a hub surface is formed to be positioned more on a rear side in a rotation direction of the turbine blade than a shroud-side end portion at the leading edge, and
a straight line, connecting between the shroud-side end portion and the hub-side end portion, is inclined with respect to a straight line, extending in a rotation axis direction from the shroud-side end portion at the leading edge onto the hub surface, by an angle in a range from 30° to 70° in a radial direction view of the turbine blade.

2. The radial turbine blade according to claim 1 , wherein a line segment, connecting between a leading edge hub position on a leading edge hub circle formed by connecting between leading edges of a plurality of the turbine blades on the hub surface and a center line of rotation of the turbine blade, is positioned more on the rear side in the rotation direction of the turbine blade about the center line of rotation of the turbine blade than a line segment, connecting between a rear edge hub position on a rear edge hub circle formed by connecting between rear edges of the plurality of turbine blades on a hub and the center line of rotation of the turbine blade.

3. The radial turbine blade according to claim 2 , wherein a line segment, connecting between a leading edge shroud position on a leading edge shroud circle formed by connecting leading edges of the plurality of turbine blades on a shroud side and the center line of rotation of the turbine blade, is positioned more on the rear side in the rotation direction of the turbine blade about the center line of rotation of the turbine blade than a line segment, connecting between a rear edge shroud position on a rear edge shroud circle formed by connecting between rear edges of the plurality of turbine blades on the shroud side and the center line of rotation of the turbine blade.

4. The radial turbine blade according to claim 1 , wherein the leading edge of the turbine blade, connecting between the shroud-side end portion and the hub-side end portion, is formed to have a substantially linear shape in the radial direction view of the turbine blades.

5. The radial turbine blade according to claim 1 , wherein the leading edge of the turbine blade, connecting between the shroud-side end portion and the hub-side end portion, is formed to have a curved shape protruding in the rotation direction of the turbine blade in the radial direction view of the turbine blade.

6. The radial turbine blade according to claim 5 , wherein the curved shape is formed with a hub side inclined by a large inclination angle and extending along the hub surface and a shroud side inclined by a smaller inclination angle.

7. The radial turbine blade according to claim 1 , wherein the leading edge of the turbine blade, connecting between the shroud-side end portion and the hub-side end portion, has a hub side protruding in the rotation direction of the turbine blade and has a shroud side protruding in a direction opposite to the rotation direction, so that the leading edge as a whole is formed to have a substantially S shape.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Yokoyama Takao
• Tojo Masaki
• Nagae Satomi

Classifications

• F05D2240/301

  Cross-sectional characteristics · CPC title

• F02C6/12

  Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure · CPC title

• F02B37/24

  by using pumps or turbines with adjustable guide vanes · CPC title

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title

• F01D5/04

  for radial-flow machines or engines · CPC title