Method of fabricating a shaft assembly
View Patent ↗An assembly provides metallic ends to a composite shaft and a method of fabricating such an assembly. The composite shaft is preferably comprised of reinforced fibers. A metallic inner sleeve is positioned in the cavity of one end of the shaft. A metallic outer sleeve is positioned around the end of the shaft having the inner sleeve therein. The outer sleeve may include structural features, such as dimples, that ensure a stable connection between the sleeve and the shaft. The sleeves are compressibly forced onto the shaft, thereby forming the assembly. Both sleeves are metallic, and therefore provide a surface onto which weld joints can be formed. A preferred method of assembly includes the steps of expanding the inner sleeve and compressing the outer sleeve against the shaft.
1. A method of fabricating a shaft assembly comprising:
selecting a cured composite shaft member having an end portion defining a cavity, the end portion having an inner surface and an outer surface;
selecting a metallic inner sleeve having an exterior surface;
selecting a metallic outer sleeve having an interior surface;
disposing the inner sleeve within the cavity of the end portion of the shaft;
disposing the outer sleeve around the end portion of the shaft;
expanding the inner sleeve such that the exterior surface is adjacent the inner surface of the end portion of the shaft; and
compressing the outer sleeve such that the interior surface of the outer sleeve is adjacent the outer surface of the end portion of the shaft.
2. The method of claim 1 , wherein the inner sleeve further comprises a first flange and the outer sleeve further comprises a second flange.
3. The method of claim 2 , further comprising forming a joint between the first and second flanges.
4. The method of claim 3 , wherein the forming a joint includes forming a weld joint.
5. The method of claim 1 , wherein the steps of expanding the inner sleeve and compressing the outer sleeve are performed simultaneously.
6. The method of claim 1 , wherein the step of expanding the inner sleeve is performed after the step of compressing the outer sleeve.
7. The method of claim 1 , wherein the outer sleeve further comprises at least one dimple positioned on the interior surface of the outer sleeve.
8. The method of claim 7 , wherein the compressing the outer sleeve continues until an undulating interface is formed between the interior surface of the outer sleeve and the outer surface of the shaft.
9. The method of claim 1 , wherein the inner sleeve further comprises at least one dimple positioned on the exterior surface of the inner sleeve.
10. The method of claim 9 , wherein the step of expanding the inner sleeve continues until an undulating interface is formed between the exterior surface of the inner sleeve and the inner surface of the shaft.
11. A method of fabricating a shaft assembly having a hollow composite shaft, a metallic inner sleeve, and a metallic outer sleeve, the method comprising:
placing the inner sleeve within the composite shaft;
placing the outer sleeve around the composite shaft;
expanding the inner sleeve such that the inner sleeve engages the composite shaft; and
compressing the outer sleeve such that the outer sleeve engages the composite shaft, the compressing step occurring simultaneously with the expanding step.
12. The method of claim 11 , wherein the inner sleeve and the outer sleeve each include a connection portion engaging the composite shaft and a flange portion extending from the composite shaft.
13. The method of claim 12 , further comprising the step of attaching the flange portions of the inner sleeve and outer sleeve together.
14. The method of claim 13 , wherein the step of attaching the flange portions occurs prior to the expanding and compressing steps.
15. The method of claim 13 , wherein the flange portions are attached by a weld.
16. The method of claim 12 , further comprising the step of forming connection features in the flange portions.
17. The method of claim 12 , wherein at least one of the inner sleeve and outer sleeve includes an angled portion positioned between the connection portion and the flange portion.
18. The method of claim 17 , wherein the flange portions of the inner and outer sleeves define a cavity therebetween, and further comprising the steps of:
attaching the flange portions of the inner sleeve and outer sleeve together; and
placing the composite shaft within the cavity.