# US 10,502,227 B2 · Fan for a turbomachine

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- Number: US 10,502,227 B2
- Document ID: US10502227B2
- Status: Granted
- Kind: B2
- Application number: 15/039,557
- Filed: 2014-11-26
- Published: 2017-06-15
- Granted: 2019-12-10
- Earliest claimed: 2013-11-29
- Assignees: Safran Aircraft Engines
- Applicants: Safran Aircraft Engines
- Inventors: Laurent Jablonski; Philippe Gérard Edmond Joly; Christophe Perdrigeon; Damien Merlot; Hervé Pohier
- Web page: https://patentgrep.com/patent/US10502227B2

## CPC

- F04D 29/329: {Details of the hub}
- F01D 5/025: {Fixing blade carrying members on shafts (attachment of a member on a shaft in general F16D1/06; for non-positive displacement pumps F04D29/00)}
- F01D 5/14: Form or construction (selecting particular materials, measures against erosion or corrosion F01D5/28)
- F01D 5/30: Fixing blades to rotors; Blade roots {; Blade spacers}
- F01D 5/3015: {with side plates}
- F01D 5/303: {in a circumferential slot}
- F01D 5/3053: {by means of pins}
- F01D 5/3069: {between two discs or rings}
- F01D 5/32: Locking, e.g. by final locking blades or keys
- F01D 5/323: {Locking of axial insertion type blades by means of a key or the like parallel to the axis of the rotor}
- F01D 5/34: Rotor-blade aggregates of unitary construction {, e.g. formed of sheet laminae; (discs formed of sheet laminae F01D5/028; ceramic materials F01D5/284, composite materials F01D5/282)}
- F04D 19/002: {Axial flow fans}
- F04D 29/023: {especially adapted for elastic fluid pumps}
- F04D 29/053: Shafts
- F04D 29/322: {Blade mountings}
- F04D 29/38: Blades {(for axial flow compressors F04D29/324)}
- F01D 5/141: {Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147)}
- F01D 11/008: {by spacer elements between the blades, e.g. independent interblade platforms}
- F05D 2220/36: specially adapted for the fan of turbofan engines
- F05D 2260/33: with a bayonet coupling
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)
- 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

The invention proposes a fan, in particular for a turbomachine of small size such as a jet engine, having a hub ratio which corresponds to the ratio of the diameter of the inner limit of the incoming air stream (26) at the radially inner ends of the leading edges of the fan blades (10), divided by the diameter of the circle around which the outer ends of the fan blades pass, having a value of between 0.20 and 0.265.

## Claims

### Claim 1

A fan for a jet engine, the fan comprising at an intake, fan blades, an annular casing, a hub adapted to rotate around an axis and bearing the fan blades, each fan blade having a leading edge, and the fan blades extending radially relative to said axis in an annular stream delimited internally by the hub and externally by the annular casing, wherein:
said fan has an intake diameter, which corresponds to a diameter of a circle comprising radially outer ends of the fan blades, of a value of between 900 mm and 1200 mm and has a hub ratio, which corresponds to a ratio of a diameter of an inner limit of the annular stream at radially inner ends of leading edges of the fan blades, divided by the intake diameter, of a value of between 0.20 and 0.265;
the hub comprises a fan disc having, at an outer circumference, ribs formed in alternation with grooves in which blade roots are engaged;
a shim having a radial thickness of between 1 mm and 3 mm is interposed radially between one of said blade roots and one of said groove bottoms; and
said fan disc has an outer limit, formed by outer ends of the ribs, a diameter of which is between 245 mm and 275 mm, and an inner limit, formed by an inner end of an inner wall of the fan disc, a diameter of which is between 120 mm and 140 mm.

### Claim 2 (depends on 1)

The fan according to claim 1, wherein the fan disc has an outer limit, formed by outer ends of the ribs, a diameter of which is between 245 mm and 275 mm, and in that the grooves of the disc have a radial dimension between a bottom of the grooves and a top of the ribs, of a value between 18 mm and 22 mm.

### Claim 3 (depends on 1)

The fan according to claim 1, wherein the internal wall of the fan disc is formed by an internal bore of a truncated cone shape, flaring out downstream, wherein an upstream end of the internal bore defines the inner limit of the fan disc, which inner limit defines a minimum radius of the fan disc.

### Claim 4 (depends on 1)

The fan according to claim 1, wherein the fan disc bears between 17 and 21 fan blades.

### Claim 5 (depends on 4)

The fan according to claim 4, wherein the disc bears between 18 and 20 fan blades.

### Claim 6 (depends on 1)

The fan according to claim 1, wherein the disc is made of titanium alloy.

### Claim 7 (depends on 6)

The fan according to claim 6, wherein the titanium alloy corresponds to one of TA6V, TU 7, and TA5CD4.

### Claim 8 (depends on 1)

A jet engine comprising the fan according to claim 1.

### Claim 9

A fan for a jet engine, comprising at an intake, fan blades, an annular casing, a hub rotating around an axis of the turbomachine and bearing the fan blades, which extend radially relative to said axis in an annular stream delimited internally by the hub and externally by the annular casing, wherein said fan has an intake diameter (A), which corresponds to the diameter of the circle comprising the radially outer ends of the fan Hades, of a value of between 900 mm and 1200 mm and has a hub ratio, which corresponds to a ratio of the diameter (B) of the inner limit of the stream at the radially inner ends of the leading edges of the fan blades, divided by the intake diameter, of a value of between 0.20 and 0.265, the hub comprising a fan disc having, at an outer circumference, ribs formed in alternation with grooves in which roots of the fan blades are engaged, the fan disc having an outer limit, farmed by outer ends of the ribs, a diameter of which is between 245 mm and 275 mm, and an inner limit, formed by an inner end of an internal wall of the disc, a diameter of which is between 120 mm and 140 mm.

### Claim 10

A jet engine, comprising:
a fan comprising at an intake, fan blades, an annular casing, a hub rotating around an axis of the turbomachine, said hub comprising a fan disc bearing the fan blades, which fan blades extend radially relative to said axis in an annular stream delimited internally by the hub and externally by the annular casing, wherein:
said fan has an intake diameter (A), which corresponds to the diameter of the circle comprising the radially outer ends of the fan blades, of a value of between 900 mm and 1200 mm and has a hub ratio, which corresponds to a ratio of the diameter (B) of the inner limit of the stream at the radially inner ends of the leading edges of the fan blades, divided by the intake diameter, of a value of between 0.20 and 0.265, and
the hub comprises a fan disc comprising at an outer circumference ribs formed in alternation with grooves in which blades roots of the fan blades are engaged, each groove having a groove bottom, and
a shim having a radial thickness of between 1 mm and 3 mm is interposed radially between one of said blade roots and one of said groove bottoms, and
a low-pressure compressor arranged downstream from the fan disc and which abuts directly against downstream ends of the blade roots and the ribs of the fan disc, wherein said fan disc has an outer limit, formed by outer ends of the ribs, a diameter of which is between 245 mm and 275 mm, and an inner limit formed by an inner end of an inner wall of the fan disc, a diameter of which is between 120 mm and 140 mm.

### Claim 11 (depends on 10)

The jet engine of claim 10, which is devoid of hooks arranged downstream from the fan blades for axial retention of said fan blades, and the fan disc comprises:
an annular rim prolonged upstream by an annular portion comprising an annular recess of the fan disc delimited between an upstream face of the annular rim and a radial edge of the fan disc extending externally, and
a flange disposed in the annular recess and forming there an axial abutment of the blade roots in the upstream direction.

### Claim 12 (depends on 11)

The jet engine of claim 11, wherein the flange is delimited at a downstream end by a radial face abutting against the fan blades, said downstream end of the flange comprising an inner annular edge which is castellated and comprises solid sections alternating with hollow sections and has shapes substantially matching shapes of said radial edge of the fan disc, to allow an axial securing of the flange in the annular recess of the fan disc by abutment of solid sections of an edge of the flange against solid sections of the radial edge of the fan disc.

### Claim 13 (depends on 10)

The jet engine of claim 10, wherein the grooves of the fan disc have a radial dimension between a bottom of the grooves and a top of the ribs, of a value between 18 mm and 22 mm.