US 12,140,081 B2
Midshaft rating for turbomachine engines
Narayanan Payyoor, Thrissur (IN); Weize Kang, Mason, OH (US); Brandon W. Miller, Middletown, OH (US); Bugra H. Ertas, Niskayuna, NY (US); and Andrea Piazza, Turin (IT)
Assigned to GENERAL ELECTRIC COMPANY, Evendale, OH (US); and GE AVIO S.R.L., Rivalta di Torino (IT)
Filed by General Electric Company, Schenectady, NY (US); and GE Avio S.r.l., Rivalta di Torino (IT)
Filed on Oct. 5, 2023, as Appl. No. 18/481,597.
Application 18/481,597 is a continuation of application No. 18/058,034, filed on Nov. 22, 2022, granted, now 11,808,214.
Application 18/058,034 is a continuation in part of application No. 17/328,795, filed on May 24, 2021, granted, now 11,603,801, issued on Mar. 14, 2023.
Prior Publication US 2024/0117769 A1, Apr. 11, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. F02C 7/36 (2006.01); F02C 7/06 (2006.01)
CPC F02C 7/36 (2013.01) [F02C 7/06 (2013.01); F05D 2220/32 (2013.01); F05D 2240/50 (2013.01); F05D 2240/60 (2013.01); F05D 2260/40 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A turbomachine engine comprising:
a fan section having a fan shaft;
a core engine including one or more compressor sections, one or more turbine sections that includes a power turbine, and a combustion chamber in flow communication with the compressor sections and turbine sections;
a low-speed shaft coupled to the power turbine and characterized by a midshaft rating (MSR) between two hundred (ft/sec)1/2 and three hundred (ft/sec)1/2, wherein the low-speed shaft has a redline speed between fifty and two hundred fifty feet per second (ft/sec), and the turbomachine engine is configured to operate up to the redline speed without passing through a critical speed associated with a first-order bending mode of the low-speed shaft;
a gearbox assembly that couples the fan shaft to the low-speed shaft; and
a flex coupling that couples the gearbox assembly to the low-speed shaft, the flex coupling including one or more flex plates that include gaps that absorb deflections in the low-speed shaft.