Hybrid composite-metal shaft

Patent metadata

Field	Value
Publication number	US-2016271925-A1
Application number	US-201514662406-A
Country	US
Kind code	A1
Filing date	Mar 19, 2015
Priority date	Mar 19, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

A method for making a composite-metal hybrid shaft for a rotorcraft includes providing a tubular metal member that has an internal surface defining a space therein, preparing a composite member using a curing tool, curing the composite member, creating a cured composite member, expanding the metal member with heat, placing the cured composite member into the space defined by the internal surface of the expanded metal member, and allowing the expanded metal member to cool.

First claim

1 . A method for making a composite-metal hybrid shaft for a rotorcraft, comprising:
providing a tubular metal member that includes an internal surface defining a space therein; preparing a composite member using a curing tool; curing the composite member, creating a cured composite member; expanding the metal member with heat, creating an expanded metal member; placing the cured composite member into the space defined by the internal surface of the expanded metal member; and allowing the expanded metal member to cool.

2 . The method of claim 1 , wherein the metal member is steel.

3 . The method of claim 1 , wherein the internal surface of the metal member has a groove.

4 . The method of claim 1 , wherein the external surface of the metal member has a groove.

5 . The method of claim 1 , wherein preparing the composite member on the curing tool comprises braiding dry reinforcing fibers around the curing tool and infusing the dry reinforcing fibers with epoxy resin.

6 . The method of claim 1 , wherein preparing the composite member on the curing tool comprises braiding prepreg material around the curing tool.

7 . The method of claim 1 , wherein preparing the composite member on the curing tool comprises wrapping prepreg material around the curing tool.

8 . The method of claim 1 , wherein preparing the composite member on the curing tool comprises molding in at least one of a taper and a fillet at an end portion of the composite member.

9 . The method of claim 1 , further comprising preparing a fiberglass layer on top of the composite member.

10 . The method of claim 9 , further comprising machining the fiberglass layer to correspond to the internal surface of the metal member.

11 . The method of claim 1 , further comprising machining a taper on the composite member.

12 . The method of claim 1 , further comprising machining a fillet on the composite member.

13 . The method of claim 1 , wherein the method further comprises placing an adhesive onto a portion of the cured composite member.

14 . The method of claim 1 , wherein the method further comprises freezing the cured composite member prior to placing the cured composite member into the space defined by the internal surface of the expanded metal member.

15 . The method of claim 1 , wherein curing the composite member occurs in an autoclave.

16 . The method of claim 1 , wherein curing the composite member occurs outside of an autoclave.

17 . The method of claim 1 , wherein curing the composite member occurs in a vacuum.

18 . The method of claim 1 , further comprising cooling a middle portion of the expanded metal member prior to cooling an end portion of the expanded metal member.

19 . The method of claim 18 , wherein a cooling fluid is used to cool the middle portion of the expanded metal member such that the middle portion of the expanded metal member is compressed onto the composite member prior to the end portion of the expanded metal member is compressed onto the composite member.

20 . The method of claim 19 , wherein the cooling fluid is liquid nitrogen.

Assignees

• Bell Helicopter Textron Inc

Inventors

• Kendrick Phillip A

Classifications

• B32B2311/30

  Iron, e.g. steel · CPC title

• B32B37/08 Primary

  characterised by the cooling method · CPC title

• B29C65/665 Primary

  using shrinking during cooling · CPC title

• B29C70/32

  on a rotating mould, former or core · CPC title

• B29C66/71

  characterised by the composition of the plastics material of the parts to be joined (welding bar compositions B29C65/125) · CPC title