# US 11,306,597 B2 · Composite blade and method of manufacturing composite blade

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- Number: US 11,306,597 B2
- Document ID: US11306597B2
- Status: Granted
- Kind: B2
- Application number: 16/617,672
- Filed: 2018-05-30
- Published: 2020-03-26
- Granted: 2022-04-19
- Earliest claimed: 2017-05-31
- Assignees: Mitsubishi Heavy Industries, Ltd.
- Applicants: Mitsubishi Heavy Industries, Ltd.
- Inventors: Ryoji Okabe; Kentaro Shindo; Masami Kamiya; Yoshinori Nonaka
- Web page: https://patentgrep.com/patent/US11306597B2

## CPC

- F01D 5/282: {Selecting composite materials, e.g. blades with reinforcing filaments}
- F01D 5/3007: {of axial insertion type}
- F01D 5/30: Fixing blades to rotors; Blade roots {; Blade spacers}
- F01D 5/3053: {by means of pins}
- F01D 5/147: {Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18)}
- F01D 5/3092: {Protective layers between blade root and rotor disc surfaces, e.g. anti-friction layers (F01D5/288 takes precedence)}
- F05D 2230/00: Manufacture
- F05D 2300/603: Composites; e.g. fibre-reinforced
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A composite blade includes an airfoil; and a blade root including a straight section from a blade end part being a connection location with the airfoil to an inclination start part between the blade end part and a base end, and a bearing section from the inclination start part to the base end. A laminate of composite layers with reinforced fibers impregnated with resin is provided across the airfoil and the blade root. A metal body is provided on the blade root. The laminate extends along the longitudinal direction in the airfoil and in the straight section, and extends to be inclined away from a center axis in the bearing section. The metal body is provided on both surfaces of the laminate in the blade root, extends along the longitudinal direction in the straight section, and extends to be inclined away from the center axis in the bearing section.

## Claims

### Claim 1

A composite blade comprising:
an airfoil extending in a longitudinal direction; and
a blade root including a straight section that is a section from a blade end part being a connection location with the airfoil to an inclination start part being a location between the blade end part and a base end, and a bearing section that is a section from the inclination start part to the base end, wherein
a laminate formed by laying up composite layers in which reinforced fibers are impregnated with resin is provided across the airfoil and the blade root,
a metal body is provided on the blade root,
the laminate extends along the longitudinal direction in the airfoil, extends along the longitudinal direction in the straight section, and extends so as to be inclined in a direction away from a center axis along the longitudinal direction of the airfoil toward the base end of the blade root in the bearing section,
the metal body is provided on one surface and another surface of the laminate in the blade root, extends along the longitudinal direction in the straight section, and extends so as to be inclined in a direction away from the center axis toward the base end in the bearing section,
in the metal body, an angle of a surface on an opposite side to the laminate in the bearing section with respect to the longitudinal direction is greater than an angle of a surface on the laminate side in the bearing section with respect to the longitudinal direction,
an adhesive layer is provided between the metal body and the laminate to bond the metal body and the laminate, and
on a surface on an adhesive layer side at the straight section, the metal body includes a notch part that is provided across a notch start part and the blade end part, the notch start part being between the inclination start part and the blade end part, the notch part having a depth increasing from the notch start part toward the blade end part.

### Claim 2 (depends on 1)

The composite blade according to claim 1, wherein the adhesive layer includes a soft adhesive layer provided on a blade end part side at the straight section, and a high strength adhesive layer provided at the bearing section, and the high strength adhesive layer has a higher rapture strength and a higher elastic modulus than the soft adhesive layer.

### Claim 3 (depends on 1)

The composite blade according to claim 1, wherein the adhesive layer is provided on a surface of the laminate in the airfoil, across the blade end part and an adhesive end part that is between a tip part of the airfoil on an opposite side to the blade end part and the blade end part, and the adhesive layer has a thickness increasing from the notch start part toward the blade end part in the blade root and a thickness decreasing from the blade end part toward the adhesive end part in the airfoil.

### Claim 4 (depends on 3)

The composite blade according to claim 3, further comprising an overlay part that is a sheet that covers from an end surface of the metal body in the blade end part to a surface of the laminate on the tip part side with respect to the adhesive end part, via a surface of the adhesive layer from the blade end part to the adhesive end part.

### Claim 5 (depends on 1)

The composite blade according to claim 1, wherein, on the surface at the side opposite to the laminate in the straight section, the metal body includes a thin part that is thinned to a depth at a location between the surface on the opposite side to the laminate to the surface on the laminate side.

### Claim 6 (depends on 5)

The composite blade according to claim 5, wherein the thin part is a groove that is provided across a thinning start part and the blade end part, the thinning start part being between the inclination start part and the blade end part, the thin part having a depth increasing from the thinning start part toward the blade end part.

### Claim 7 (depends on 1)

The composite blade according to claim 1, wherein
the blade root is attached to a turbine disk including a straight groove that extends along the longitudinal direction, and a bearing groove that is connected to an end part of the straight groove, and that spreads in a direction away from a center axis of the straight groove as the bearing groove is separated from an end part of the straight groove,
the straight section is disposed in the straight groove, and
the bearing section is disposed in the bearing groove.

### Claim 8

A method of manufacturing a composite blade that includes an airfoil extending in a longitudinal direction, and a blade root including a straight section that is a section from a blade end part being a connection location with the airfoil to an inclination start part being a location between the blade end part and a base end, and a bearing section that is a section from the inclination start part to the base end, the method comprising:
forming a laminate, by laying up composite layers in which reinforced fibers are impregnated with resin, across the airfoil and the blade root;
forming a metal body that is provided on the blade root, and
providing an adhesive layer between the metal body and the laminate to bond the metal body and the laminate,
wherein the forming of the laminate includes forming the laminate such that the laminate extends along the longitudinal direction in the airfoil, extends along the longitudinal direction in the straight section, and extends so as to be inclined in a direction away from a center axis along the longitudinal direction of the airfoil toward the base end of the blade root in the bearing section,
the forming of the metal body includes forming the metal body such that the metal body is provided on one surface and another surface of the laminate in the blade root, extends along the longitudinal direction in the straight section, and extends so as to be inclined in a direction away from the center axis toward the base end in the bearing section, and such that an angle of a surface of the metal body on an opposite side to the laminate in the bearing section with respect to the longitudinal direction is greater than an angle of a surface on the laminate side in the bearing section with respect to the longitudinal direction, and
the forming of the metal body is performed such that, on a surface on an adhesive layer side at the straight section, the metal body includes a notch part that is provided across a notch start part and the blade end part, the notch start part being between the inclination start part and the blade end part, the notch part having a depth increasing from the notch start part toward the blade end part.