Abstract: A support structure in a gas turbine combustor end cap (24) including a bracket (60) with a first leg (61) and a second leg (62) forming a generally trapezoidal geometry. Each leg has a first end (61A, 62A) attached to an inner concentric ring (46), and a second end (61B, 62B) attached to a crossbar (65). The crossbar is attached to an outer concentric ring (48). A circular array of such brackets interconnects the two concentric rings (46, 48). Each leg has at least one curved middle portion (63, 64), such as an arcuate or sinusoidal curve at a midpoint on the length of each leg. This shape provides flexibility in a radial direction that accommodates differential thermal expansion of the concentric rings while providing a rigid connection in an axial direction.

Abstract: A gas turbine combustor cap assembly (24) including a pre-mix tube (42, 44) with an upstream flange (60, 62) that aligns and seats the tube against a primary feed plate (66) attached to an upstream end of a support ring (48). The pre-mix tube may have an intermediate flange (64) at an intermediate position on the length of the tube that aligns and seats the tube against an intermediate structural frame (68) attached to the support ring at an intermediate position on the length of the support ring. The combustor cap assembly (24) may have multiple pre-mix tubes, including a central pre-mix tube (44) with upstream (62) and intermediate (64) flanges and a circular array of outer pre-mix tubes (44) with at least an upstream flange (64).

Abstract: A nut (64) is affixed to an outer surface of a transition impingement sleeve forward ring (50) that encircles, and is affixed to, a forward end (44) of a tubular transition impingement sleeve (45). The nut has a threaded hole (63) aligned with a hole (66) in the impingement sleeve forward ring. A machine screw (68) is threaded into the nut and extends through the hole (66), and has a radially inner end with a wear pad (70), and a radially outer end with a turning tool engagement element (72). The wear pad contacts an outer surface of an aft portion of a transition piece forward outer ring (52) that is surrounded by the transition impingement sleeve forward ring (50). The rotational position of the machine screw (68) sets a radial gap (76) between the transition impingement sleeve forward ring and the transition piece forward outer ring.

Abstract: An intermediate support frame (68) that spans an inner diameter of a support ring (48) of a gas turbine combustor cap assembly (24) at a position intermediate the length of the support ring. The intermediate support frame may have a central encirclement (72) that receives a central fuel pre-mix tube (44) of the combustor cap assembly, and may further have a circular array of outer stabilization rings (70) that each receive a respective outer pre-mix tube (42). The central pre-mix tube may be affixed to the central encirclement (72), for example by welding. The outer pre-mix tubes may be slidably engaged in the outer stabilization rings (70), providing lateral stability while allowing differential thermal expansion. The intermediate support frame may have holes (74) for coolant passage, and perimeter tabs (76) for attachment to the support ring (48).

Abstract: A support structure in a gas turbine combustor end cap (24) including a bracket (60) with a first leg (61) and a second leg (62) forming a generally trapezoidal geometry. Each leg has a first end (61A, 62A) attached to an inner concentric ring (46), and a second end (61B, 62B) attached to a crossbar (65). The crossbar is attached to an outer concentric ring (48). A circular array of such brackets interconnects the two concentric rings (46, 48). Each leg has at least one curved middle portion (63, 64), such as an arcuate or sinusoidal curve at a midpoint on the length of each leg. This shape provides flexibility in a radial direction that accommodates differential thermal expansion of the concentric rings while providing a rigid connection in an axial direction.

Abstract: A nut (64) is affixed to an outer surface of a transition impingement sleeve forward ring (50) that encircles, and is affixed to, a forward end (44) of a tubular transition impingement sleeve (45). The nut has a threaded hole (63) aligned with a hole (66) in the impingement sleeve forward ring. A machine screw (68) is threaded into the nut and extends through the hole (66), and has a radially inner end with a wear pad (70), and a radially outer end with a turning tool engagement element (72). The wear pad contacts an outer surface of an aft portion of a transition piece forward outer ring (52) that is surrounded by the transition impingement sleeve forward ring (50). The rotational position of the machine screw (68) sets a radial gap (76) between the transition impingement sleeve forward ring and the transition piece forward outer ring.

Abstract: An intermediate support frame (68) that spans an inner diameter of a support ring (48) of a gas turbine combustor cap assembly (24) at a position intermediate the length of the support ring. The intermediate support frame may have a central encirclement (72) that receives a central fuel pre-mix tube (44) of the combustor cap assembly, and may further have a circular array of outer stabilization rings (70) that each receive a respective outer pre-mix tube (42). The central pre-mix tube may be affixed to the central encirclement (72), for example by welding. The outer pre-mix tubes may be slidably engaged in the outer stabilization rings (70), providing lateral stability while allowing differential thermal expansion.

Abstract: A gas turbine combustor cap assembly (24) including a pre-mix tube (42, 44) with an upstream flange (60, 62) that aligns and seats the tube against a primary feed plate (66) attached to an upstream end of a support ring (48). The pre-mix tube may have an intermediate flange (64) at an intermediate position on the length of the tube that aligns and seats the tube against an intermediate structural frame (68) attached to the support ring at an intermediate position on the length of the support ring. The combustor cap assembly (24) may have multiple pre-mix tubes, including a central pre-mix tube (44) with upstream (62) and intermediate (64) flanges and a circular array of outer pre-mix tubes (44) with at least an upstream flange (64).