Generator rotor pole crossover
View Patent ↗The present invention increases the life of a pole crossover while minimizing the need for timely inspections and costly replacements. The present invention splits the pole crossover band 4 at one or more locations along its circumference and then joins the multiple arcs with a flexible member 10 , such as an omega shaped bow. As deflection related stresses 8 increase, the circumference of the pole crossover band, the flexible member 10 allows for a natural expansion point in the otherwise rigid material. This relieves stresses that would otherwise be transferred to the connection point 6 between the pole crossover and the generator windings that can cause cracking and eventually generator failure.
1. A pole crossover with a deflection stress reducing section comprising:
a band, wherein said band is at least one of circular and semi-circular;
two axial arms;
two joints, wherein said two joints connect said two axial arms with said band; and
at least one flexible member;
wherein said at least one flexible member intersects said band wherein said band is divided into at least two arcs joined by said flexible member;
wherein said at least one flexible member is capable of expanding to reduce deflection stresses when the circumference of said band increases.
2. The pole crossover of claim 1 , wherein one flexible member is present when said band is semi-circular and two flexible members are present when said band is circular.
3. The pole crossover of claim 1 , wherein said flexible member divides said band into approximately equal arcs.
4. The pole crossover of claim 1 , wherein said pole crossover is manufactured as a contiguous unit.
5. The pole crossover of claim 1 , wherein said flexible member is an omega shaped bow.
6. The pole crossover of claim 5 , wherein said omega shaped bow comprises a plurality of stacked thin sheet laminations.
7. The pole crossover of claim 6 , wherein said plurality of stacked thin sheet laminations are composed essentially of copper.
8. The pole crossover of claim 5 , wherein said omega shaped bow is joined to said band via struts that are raised on the inner circumference of said band.
9. The pole crossover of claim 1 , wherein said flexible member is recessed in relation to the outer circumference of said band.
10. A pole crossover with a deflection stress reducing section comprising:
a band;
two struts; and
an omega shaped bow with an integral loop;
wherein said omega shaped bow intersects said band, dividing said band into separate arcs;
wherein said omega shaped bow is joined to said band via said two struts, and wherein said struts are raised on the inner circumference of said band such that said omega shaped bow is oriented such that said integral loop is oriented outwardly and said omega shaped bow is recessed in respect to the outer circumference of said band;
wherein said omega shaped bow is comprised of a plurality of stacked thin sheet laminations;
wherein said omega shaped bow reduces deflection stresses created by the expansion of said band.
11. The pole crossover of claims 10 , wherein said plurality of stacked thin sheet laminations comprise 2-16 thin sheets.
12. The pole crossover of claims 11 , wherein said plurality of stacked thin sheet laminations comprise 8-12 thin sheets.
13. The pole crossover of claims 10 , wherein said thin sheets are approximately 0.016-0.125 inches (0.041-0.318 cm) in thickness.
14. The pole crossover of claims 10 , wherein said omega shaped bow is approximately 0.016-0.125 inches (0.041-0.318 cm) thick, 1.5-2.5 inches (3.8-6.3 cm) wide and 3.5-5.0 inches (8.8-12.5 cm) long.
15. The pole crossover of claims 10 , wherein said omega shaped bow intersects said band at approximately the band's midway point.
16. The pole crossover of claims 10 , wherein a plurality of said omega shaped bows intersect said band.
17. An apparatus for allowing an expansion area within a pole crossover band comprising:
an omega shaped bow, wherein said omega shaped bow divides said pole crossover band into separate arcs; and
two struts on said separate arcs that are raised on the inner circumference of said separate arcs;
wherein said omega shaped bow joins said separate arcs via said two struts and wherein said omega shaped bow is oriented such that the integral loop of the omega shaped bow is oriented outwardly with respect to said pole crossover band and wherein said omega shaped bow is recessed with respect to the outer circumference of said pole crossover band;
wherein said omega shaped bow allows for expansion of said pole crossover band without the creation of deflection related stresses;
wherein said omega shaped bow is made of a plurality of stacked thin sheet laminations.
18. The apparatus of claim 17 , wherein said omega shaped bow is recessed approximately 0.1-0.2 inches (0.25-0.5 cm).
19. The apparatus of claim 17 , wherein said plurality of stacked thin sheet laminated are copper.