Methods and apparatus for maintaining airfoil-shaped body using cart that follows trailing edge
A motorized rolling maintenance cart that utilizes the angled trailing edge geometry of an airfoil-shaped body (such as a wind turbine blade or rotor blade) to traverse the length of the airfoil-shaped body. The trailing edge-following maintenance cart may be used to carry personnel doing maintenance activities on the blades, such as local repairs or re-painting. In accordance with one aspect, the maintenance cart carries non-destructive inspection sensor units or other maintenance hardware over the surface of the airfoil-shaped body (e.g., in a spanwise direction). In accordance with another aspect, the trailing edge-following maintenance cart is configured to also provide fall protection to one or more independently movable crawler vehicles by means of cables. Alternative embodiments may include only one of the two aspects.
1. An apparatus comprising:
a backbone structure;
a suspension system comprising first through fourth suspension arms which are non-articulated and fixedly coupled to and extending downward from the backbone structure;
first through fourth stabilizing wheels respectively supported by and rotatable relative to the first through fourth suspension arms; and
a motor operatively coupled to drive rotation of the first stabilizing wheel,
wherein the first through fourth stabilizing wheels are arranged relative to the backbone structure in a configuration such that the first and third stabilizing wheels would contact and be rollable on one side of an airfoil-shaped body and the second and fourth stabilizing wheels would contact and be rollable on another side of the airfoil-shaped body while the suspension system suspends the backbone structure over a generally horizontal trailing edge of the airfoil-shaped body.
2. The apparatus as recited in claim 1 , comprising first through fourth multiplicities of wheels, wherein the first through fourth stabilizing wheels are respectively included in the first through fourth multiplicities of wheels, and the suspension system comprises
first through fourth multiplicities of rocker arms respectively rotatably coupled to the first through fourth suspension arms, the first through fourth multiplicities of wheels being respectively rotatably coupled to the first through fourth multiplicities of rocker arms.
3. The apparatus as recited in claim 1 , further comprising:
first and second NDI sensor unit supports rotatably coupled to the backbone structure; and
first and second NDI sensor units respectively fixedly coupled to the first and second NDI sensor unit supports.
4. The apparatus as recited in claim 1 , wherein the first stabilizing wheel is a wheel probe.
5. The apparatus as recited in claim 1 , further comprising:
a cable spool rotatably coupled to the backbone structure;
a spool motor mounted to the backbone structure and operatively coupled to drive rotation of the cable spool;
a cable having a portion wound on the cable spool; and
a crawler vehicle attached to one end of the cable, the crawler vehicle comprising a frame, a set of wheels rotatably coupled to the frame, at least one vacuum adherence device coupled to the frame, and a maintenance tool carried by the frame.
6. The apparatus as recited in claim 1 , further comprising:
a cable having one end attached to the backbone structure; and
a crawler vehicle attached to the cable, the crawler vehicle comprising:
a frame;
a set of wheels rotatably coupled to the frame;
at least one vacuum adherence device coupled to the frame;
a maintenance tool carried by the frame;
a cable spool rotatably coupled to the frame; and
a spool motor mounted to the frame and operatively coupled to drive rotation of the cable spool.
7. The apparatus as recited in claim 1 , wherein the backbone structure comprises a truss bridge.
8. The apparatus as recited in claim 1 , wherein the suspension system further comprises:
first and second rocker arms respectively rotatably coupled to the first and second suspension arms, the first and
second stabilizing wheels being respectively rotatably coupled to the first and second rocker arms; and
first and second rocker helical torsion springs which are arranged to respectively assist rotations of the first and second rocker arms that would cause the first and second stabilizing wheels to respectively move toward each other.
9. The apparatus as recited in claim 8 , wherein the suspension system further comprises:
a standoff support frame rotatably coupled to the first rocker arm;
a sensor affixed to the standoff support frame;
a standoff wheel rotatably coupled to the standoff support frame,
wherein the sensor is separated from a plane that is tangent to both the first stabilizing wheel and the standoff wheel by a standoff distance.
10. The apparatus as recited in claim 8 , further comprising first and second vertical wheels, wherein the suspension system further comprises:
third and fourth rocker arms rotatably coupled to the backbone structure, the first and second vertical wheels being rotatably coupled to the third and fourth rocker arms respectively; and
third and fourth rocker helical torsion springs which are arranged to respectively assist rotations of the third and fourth rocker arms that would cause the first and second vertical wheels to move away from the backbone structure.
11. The apparatus as recited in claim 10 , wherein each of the first and second vertical wheels is a respective wheel having an annular groove configured to receive a portion of the trailing edge of the airfoil-shaped body.
12. An apparatus comprising:
a backbone structure;
first and second vertical wheels;
a suspension system comprising first through fourth suspension arms fixedly coupled to and extending downward from the backbone structure;
first through fourth stabilizing wheels respectively supported by and rotatable relative to the first through fourth suspension arms; and
a motor operatively coupled to drive rotation of the first stabilizing wheel,
wherein the first through fourth stabilizing wheels are arranged relative to the backbone structure in a configuration such that the first and third stabilizing wheels would contact and be rollable on one side of an airfoil-shaped body and the second and fourth stabilizing wheels would contact and be rollable on another side of the airfoil-shaped body while the suspension system suspends the backbone structure over a generally horizontal trailing edge of the airfoil-shaped body; and
wherein the suspension system further comprises:
first and second rocker arms respectively rotatably coupled to the first and second suspension arms, the first and second stabilizing wheels being respectively rotatably coupled to the first and second rocker arms;
first and second rocker helical torsion springs which are arranged to respectively assist rotations of the first and second rocker arms that would cause the first and second stabilizing wheels to respectively move toward each other;
third and fourth rocker arms rotatably coupled to the backbone structure, the first and second vertical wheels being rotatably coupled to the third and fourth rocker arms respectively; and
third and fourth rocker helical torsion springs which are arranged to respectively assist rotations of the third and fourth rocker arms that would cause the first and second vertical wheels to move away from the backbone structure.
13. The apparatus as recited in claim 12 , wherein each of the first and second vertical wheels is a respective wheel having an annular groove configured to receive a portion of the trailing edge of the airfoil-shaped body.
14. The apparatus as recited in claim 12 , comprising first through fourth multiplicities of wheels, wherein the first through fourth stabilizing wheels are respectively included in the first through fourth multiplicities of wheels, and the suspension system comprises first through fourth multiplicities of rocker arms respectively rotatably coupled to the first through fourth suspension arms, the first through fourth multiplicities of wheels being respectively rotatably coupled to the first through fourth multiplicities of rocker arms.
15. The apparatus as recited in claim 12 , wherein the suspension system further comprises:
a standoff support frame rotatably coupled to the first rocker arm;
a sensor affixed to the standoff support frame;
a standoff wheel rotatably coupled to the standoff support frame,
wherein the sensor is separated from a plane that is tangent to both the first stabilizing wheel and the standoff wheel by a standoff distance.
16. The apparatus as recited in claim 12 , further comprising:
first and second NDI sensor unit supports rotatably coupled to the backbone structure; and
first and second NDI sensor units respectively fixedly coupled to the first and second NDI sensor unit supports.
17. The apparatus as recited in claim 12 , wherein the first stabilizing wheel is a wheel probe.
18. The apparatus as recited in claim 12 , further comprising:
a cable spool rotatably coupled to the backbone structure;
a spool motor mounted to the backbone structure and operatively coupled to drive rotation of the cable spool;
a cable having a portion wound on the cable spool; and
a crawler vehicle attached to one end of the cable, the crawler vehicle comprising a frame, a set of wheels rotatably coupled to the frame, at least one vacuum adherence device coupled to the frame, and a maintenance tool carried by the frame.
19. The apparatus as recited in claim 12 , further comprising:
a cable having one end attached to the backbone structure; and
a crawler vehicle attached to the cable, the crawler vehicle comprising:
a frame;
a set of wheels rotatably coupled to the frame;
at least one vacuum adherence device coupled to the frame;
a maintenance tool carried by the frame;
a cable spool rotatably coupled to the frame; and
a spool motor mounted to the frame and operatively coupled to drive rotation of the cable spool.
20. An apparatus comprising:
a backbone structure;
first and second vertical wheels;
a suspension system comprising first through fourth suspension arms fixedly coupled to and extending downward from the backbone structure;
first through fourth stabilizing wheels respectively supported by and rotatable relative to the first through fourth suspension arms; and
a motor operatively coupled to drive rotation of the first stabilizing wheel,
wherein the first through fourth stabilizing wheels are arranged relative to the backbone structure in a configuration such that the first and third stabilizing wheels would contact and be rollable on one side of an airfoil-shaped body and the second and fourth stabilizing wheels would contact and be rollable on another side of the airfoil-shaped body while the suspension system suspends the backbone structure over a generally horizontal trailing edge of the airfoil-shaped body; and
wherein the suspension system further comprises:
first and second rocker arms rotatably coupled to the backbone structure, the first and second vertical wheels being rotatably coupled to the first and second rocker arms respectively; and
first and second rocker helical torsion springs which are arranged to respectively assist rotations of the first and second rocker arms that would cause the first and second vertical wheels to move away from the backbone structure.
21. The apparatus as recited in claim 20 , wherein each of the first and second vertical wheels is a respective wheel having an annular groove configured to receive a portion of the trailing edge of the airfoil-shaped body.
22. The apparatus as recited in claim 20 , wherein the backbone structure comprises a truss bridge.