Office Action 1: Non-Final Rejection (2024-09-30)
Rejection types: 102 - Lack of Novelty, 103 - Obviousness

CLAIMS:
WE CLAIM:
1\. A gas turbine engine, comprising: a fan section comprising a fan rotatable with a fan shaft; a turbomachinery section comprising a turbine and a turbomachine shaft rotatable with the turbine; a power gearbox mechanically coupled to the fan shaft and the turbomachine shaft such that the fan shaft is rotatable by the turbomachine shaft across the power gearbox; a grounded structure coupled to and supporting the power gearbox; and a torque monitoring system comprising a gearbox sensor, the gearbox sensor coupled to the grounded structure, the torque monitoring system configured to determine a torque across the power gearbox using the gearbox sensor.
2\. The gas turbine engine of claim 1, wherein the power gearbox comprises an epicyclical power gearbox or a compound epicyclical power gearbox including a static member coupled to the grounded structure.
3\. The gas turbine engine of claim 1, wherein the power gearbox comprises: a sun gear including a plurality of teeth, the sun gear drivingly coupled to the turbomachine shaft of the gas turbine engine; a plurality of planet gears circumscribing the sun gear, each of the planet gears including a plurality of teeth meshing with the teeth of the sun gear such that rotation of the sun gear causes rotation of each planet gear of the plurality of planet gears; a ring gear circumscribing the plurality of planet gears, the ring gear including a plurality of teeth meshing with the teeth of each of the planet gears such that the ring gear rotates relative to the plurality of planet gears; and a planet carrier coupled to each planet gear of the plurality of planet gears and to the grounded structure such that the planet carrier supports the power gearbox relative to the grounded structure.
4\. The gas turbine engine of claim 3, further comprising: a frame, wherein the grounded structure is coupled to the frame of the gas turbine engine.
5\. The gas turbine engine of claim 4, wherein the gearbox sensor is operable to sense data indicative of a deflection of the grounded structure to determine the torque across the power gearbox.
6\. The gas turbine engine of claim 1, wherein the torque monitoring system comprises a controller, and wherein the controller is operably coupled with the gearbox sensor.
7\. The gas turbine engine of claim 6, wherein: the fan comprises a fixed pitch fan; and the controller is configured to: receive data indicative of the torque across the power gearbox; determine the torque across the power gearbox exceeds a lower torque threshold using the received data indicative of the torque across the power gearbox; perform at least one corrective action in response to determining the torque across the power gearbox exceeds the lower torque threshold; determine the torque across the power gearbox exceeds an upper torque threshold using the received data indicative of the torque across the power gearbox; and reduce a supply of fuel to the gas turbine engine in response to determining the torque across the power gearbox exceeds the upper torque threshold.
8\. The gas turbine engine of claim 7, wherein the at least one corrective action includes reducing a rotational speed of the fan shaft, reducing a flow of fuel to the gas turbine engine, or both.
9\. The gas turbine engine of claim 7, wherein the controller is further configured to: determine the torque across the power gearbox is less than or equal to the upper torque threshold; and determine the torque across the power gearbox is within a normal operating range using the received data indicative of the torque across the power gearbox in response to determining the torque across the power gearbox is less than or equal to the upper torque threshold.
10\. The gas turbine engine of claim 7, wherein the controller is further configured to: determine the torque across the power gearbox is less than or equal to the upper torque threshold; determine the torque across the power gearbox is outside a normal operating range using the received data indicative of the torque across the power gearbox in response to determining the torque across the power gearbox is less than or equal to the upper torque threshold; and perform the at least one corrective action in response to determining the torque across the power gearbox is outside the normal operating range.
11\. The gas turbine engine of claim 6, wherein: the fan comprises a variable pitch fan; and the controller is configured to: receive data indicative of the torque across the power gearbox; determine the torque across the power gearbox exceeds a normal operating range using the received data indicative of the torque across the power gearbox; in response to determining that the torque across the power gearbox exceeds the normal operating range, determine the torque across the power gearbox exceeds a lower torque threshold using the received data indicative of the torque across the power gearbox; in response to determining that the torque across the power gearbox exceeds the lower torque threshold, perform a first corrective action; and in response to determining that the torque across the power gearbox is less than or equal to the lower torque threshold, perform a second corrective action.
12\. The gas turbine engine of claim 11, wherein: the first corrective action comprises adjusting a pitch of one or more blades of the fan, increasing a rotational speed of the fan, or both; and the second corrective action comprises reducing the rotational speed of the fan, reducing a flow of fuel to the gas turbine engine, adjusting the pitch of the one or more blades of the fan to a failsafe speed schedule, adjusting a flow of bleed air from a working gas flow path of the gas turbine engine via a variable bleed valve, or a combination thereof.
13\. The gas turbine engine of claim 11, wherein, in response to determining that the torque across the power gearbox exceeds the lower torque threshold, the controller is further configured to: determine the torque across the power gearbox is less than or equal to a mid-torque threshold; and in response to determining the torque across the power gearbox is less than or equal to the mid-torque threshold, determine the torque across the power gearbox is within the normal operating range.
14\. The gas turbine engine of claim 13, wherein, in response to determining the torque across the power gearbox is less than or equal to the mid-torque threshold, the controller is further configured to: determine the torque across the power gearbox is outside the normal operating range; perform the first corrective action; determine the torque across the power gearbox is less than or equal to the mid-torque threshold; and in response to determining the torque across the power gearbox is less than or equal to the mid-torque threshold, determine the torque across the power gearbox is within the normal operating range.
15\. The gas turbine engine of claim 13, wherein, the controller is further configured to: determine the torque across the power gearbox exceeds the mid-torque threshold; and in response to the torque across the power gearbox exceeding the mid-torque threshold, perform the second corrective action, determine the torque across the power gearbox is less than or equal to an upper torque threshold, and in response to the torque across the power gearbox being less than or equal to the upper torque threshold, determine the torque across the power gearbox is within the normal operating range.
16\. The gas turbine engine of claim 11, wherein, in response to determining that the torque across the power gearbox is less than or equal to the lower torque threshold and performing the second corrective action, the controller is further configured to: determine the torque across the power gearbox is less than or equal to an upper torque threshold; and in response to the torque across the power gearbox being less than or equal to the upper torque threshold, determine the torque across the power gearbox is within the normal operating range.
17\. The gas turbine engine of claim 16, wherein, the controller is further configured to: determine the torque across the power gearbox exceeds the upper torque threshold; and in response to the torque across the power gearbox exceeding the upper torque threshold, reduce a flow of fuel to the gas turbine engine.
18\. The gas turbine engine of claim 16, wherein, the controller is further configured to: determine the torque across the power gearbox is outside the normal operating range; and in response to determining the torque across the power gearbox is outside the normal operating range, reduce a rotational speed of the fan, reduce a flow of fuel to the gas turbine engine, or both reduce the rotational speed of the fan and reduce the flow of fuel to the gas turbine engine, adjust a pitch of one or more blades of the fan to a failsafe speed schedule, determine the torque across the power gearbox is less than or equal to the upper torque threshold, and in response to the torque across the power gearbox being less than or equal to the upper torque threshold, determine the torque across the power gearbox is healthy.
19\. A method for a gas turbine engine including a fan section having a fan rotatable with a fan shaft, a turbomachinery section having a turbine and a turbomachine shaft rotatable with the turbine, and a power gearbox mechanically coupled to the fan shaft and the turbomachine shaft, the method comprising: determining, using data indicative of a torque across the power gearbox, that the torque across the power gearbox is greater than a lower torque threshold; performing at least one corrective action in response to determining the torque across the power gearbox exceeds the lower torque threshold; determining the torque across the power gearbox exceeds an upper torque threshold using the data indicative of the torque across the power gearbox; and reducing a supply of fuel to the gas turbine engine in response to determining the torque across the power gearbox exceeds the upper torque threshold.
20\. The method of claim 19, wherein receiving data indicative of the torque across the power gearbox comprises: receiving data indicative of the torque across the power gearbox from a gearbox sensor of a torque monitoring system, the gearbox sensor coupled to a grounded structure of the gas turbine engine, the grounded structure coupled to and supporting the power gearbox.

OFFICE ACTION:
DETAILED ACTION
Notice of Pre-AIA  or AIA  Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1-6 is/are rejected under 35 U.S.C. 102(a1, a2) as being anticipated by US 2020/0088595 to Razak et al. (R1).
In Re Claim 1:
R1 shows:
A gas turbine engine, comprising:
A fan section(Fig. 2, 23) comprising a fan(23) rotatable with a fan shaft(25);
A turbomachinery section(Fig. 1, 19) comprising a turbine(19) and a turbomachine shaft(26) rotatable with the turbine;
A power gearbox(Fig. 2, 30) coupled to the fan shaft and the turbomachine shaft such that the fan shaft is rotatable with the turbomachine across the power gearbox;
A grounded structure(24) coupled to and supporting the power gearbox; and
A torque monitoring system (Fig. 7, 52C) comprising a gearbox sensor(52C), the gearbox sensos coupled to the grounded structure(24, 40), the torque monitoring system configured to determine a torque across the power gearbox using the gearbox sensor. [Per Page 9, ¶161-Page 10, ¶166 discloses detecting a torque on the carrier/grounded structure, to determine the torque of the inlet and outlet shafts.  Page 6, ¶129-130 discloses the generic fan/turbine/gearbox structures, shafts, and static structure.]
In Re Claims 2-6:
R1 shows:
The gas turbine of claim 1, wherein:
(Claim 2) the power gearbox comprises an epicyclical power gearbox or a compound epicyclical power gearbox including a static member (34) coupled to the grounded structure. [Pare Page 9, ¶161-162, the carrier(34) is static and coupled to the grounded structure (24). Page 6, ¶130 discloses gearbox 30 is epicyclic.]
(Claim 3) the power gearbox comprises:
A sun gear(Fig. 3, 28) including a plurality of teeth, the sun gear drivingly coupled to the turbomachine shaft of the gas turbine engine; [Page 6, ¶131 discloses said sun gear. Figure 3 shows the teeth.]
A plurality pf planet gears(32) circumscribing the sung ear, each of the planet gears including a plurality of teeth meshing with the teeth of the sun gear such that rotation of the un gear causes rotation of each planet gear of the plurality of planet gears; [Figure 3 shows the planet  gears plurality and teeth.]
A ring gear(38) circumscribing the plurality of planet gears, the ring gear including a plurality of teeth meshing with the teeth of each of the plant gears such that the ring gear rotates relative to the plurality of planet gears;
A planet carrier (34) coupled to each of the plurality of planet gears and to the grounded structure such that the planet carrier supports the power gearbox relative to the grounded structure. [Page 9, ¶161-162 lays out the embodiment where the ring gear rotates and the planet carrier is static.]
(Claim 4) claim 3, a frame(Fig. 1, 24), wherein the grounded structure is coupled to the frame of the gas turbine engine. [Figure 2 shows element(24) includes frame legs into the gearbox interior. Page 9, ¶161-162 lays out the carrier is coupled to the frame(24) via linkages(40).]
(Claim 5) claim 4, the gearbox is operable to sense data indicative of a deflection of the grounded structure to determine the torque across the power gearbox. [Page 9, ¶161-193 lays out measuring the torque. Page 8, ¶140-142, shows how the force sensors can be pressure bladders detecting the pressure applied by the carrier to the static structure, this pressure is caused by deflecting of the carrier to press against aid elements.]
(Claim 6) the torque monitoring system comprises a controller(Fig. 2, 58), and wherein the controller is operably coupled with the gearbox sensor. [Page 10, ¶165-166 discloses the elements are connected.]
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 7- 17, and 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over R1 in view of US 2018/0171816 to Moniz et al. (M1) and US 2,678,698 to Lee II, (L1).
In Re Claim 7:
R1 teaches:
The gas turbine engine of claim 6,wherein:
The fan comprises a fixed pitch fan; and [Figure 1 shows a normal fan without pitch change structure.]
The controller is configured to:
Receive data indicative of the torque across the power gearbox; [Page 9, ¶161-163 discloses the measuring of variables speed and reactionary torque to determine gearbox torque. Page 10, ¶164-165 discloses this information delivered to a processor.]
Determine the thrust across the power gearbox exceeds a lower thrust threshold using the received data indicative of the torque across the power gearbox; [Page 10,¶166 discloses the thrust being lower or high.]
Perform at least one corrective action in response to determining the thrust across the power gearbox exceeds the lower thrust threshold; [Page 10, ¶166 discloses increasing fuel flow if the thrust is low.]
Determine the thrust across the power gearbox exceeds an upper thrust threshold using the received data indicative of the torque across the power gearbox; [Page 10,¶166 discloses the thrust being lower or high.]
Reduce a supply of fuel to the gas turbine engine in response to determining the thrust across the power gearbox exceeds the upper thrust threshold; [Page 10, ¶166 discloses decreasing fuel flow if the thrust is high.]
R1 does not teach:
The controller is using a Torque upper threshold and a torque lower threshold to activate control actions as claimed.
M1 teaches:
Using torque measurements to determine control actions directly. [Fig. 8, elements 212-224.]  In particular if the torque outside the range (the examiner notes a ranges can have upper and lower limits given these are operational ranges as laid out in Page 6, ¶59) can determine actions such as reducing fuel supply. [Page 6, ¶62] As these torque values can indicate they are indicative of a failure of some part of the gearbox.[Page 6, ¶58-63.]  A particular exemplary condition is an under torque value (Page 6, ¶61-63.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 to include using the torque measurements directly to determine if the engine is outside an anticipated operational torque range, and to enact controls in response to reduce fuel supply, with the expectation of successfully reducing the change of damage to the engine during gearbox failures.] This would yield the limitation of the controller using a torque thresholds to active the controller, and in particular the lower torque threshold triggering a control action, such as fuel reduction.
R1 as modified by M1 does not explicitly disclose:
The torque thresholds includes an upper torque threshold to active the reduction of the fuel supply.
L1 teaches:
It is known to control a turbine(Figure 1, 10) with a fan, to utilize Torque thresholds to determine controlled actions with regards to fuel.  In particular measuring torque across the engine (Col. 9, ll. 20-40.] and determining if a Torque is a mid-level (correct), and not in an upper level (Torque High) or lower level (Torque Low), in various operating conditions (A, correct//C, High, and G//LOW) when combined with speed measurements, to enact either normal operation, (Correct or mid-level torque)  or to reduce the fuel (high or low torque conditions C and G). [Col. 10, ll. 45-59m  for operation A.  Col. 12, ll. 65 – Col., 13, l. 17 for operation C, upper torque threshold, and Col. 14, ll. 10-23, for operation G, lower Torque threshold.  C and G also disclose reducing fuel supply.]  These control values are utilized because Torque is related to thrust, and a more efficient operation of the engine can be operated by regulating fuel flow by torque to satisfy recognized in the art desirable operational requirements of torque and engine speed. [Col. 1, ll. 5-46, Col. 2, ll. 10-37.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 and M1, to use the preexisting torque and speed monitoring, sensors and controllers of those systems, with the controller recognizing the thresholds and operational states as taught by L1 with the expectation of successfully improving keeping the engine operating in a desirable and efficient operational requirement of torque and engine speed. This would yield the limitation of the controller reducing the fuel supply during upper Torque threshold limit exceeding during certain engine speed conditions.[Col. 1, ll. 5-46, Col. 2, ll. 10-37.]  This would yield the limitation of reducing the supply of fuel to the gas turbine engine in response to determining the torque across the power gearbox exceeds the upper torque threshold.
In Re Claims 8-10:
R1 as modified by M1 and L1 would teach:
The gas turbine engine of claim 7, wherein:
M1 and L1 further teach:
(Claim 8) the at least one corrective action includes reducing a rotational speed of the fan shaft, reducing a flow of fuel to the gas turbine engine or both [M1 discloses  under torque threshold causing fuel reduction. [M1, Page 6, ¶60-62 discloses under torque triggering fuel reduction.  L1, Col. 14, ll. 10-23 discloses low torque threshold triggering a fuel reduction.]
(Claim 9) the controller is configured to:
Determine the torque across the power gearbox is less than or equal to the upper torque threshold; and
Determine the torque across the power gearbox is within a normal operating range using the received data indicative of the torque across the power gearbox in response to determining the torque across the power gearbox is less than or equal to the upper torque threshold. [M1, Page 6, ¶58-62 discloses determining if the torque is within a desired range.  A desired range would be less than or equal to an upper limit, and further is normal as it is above the lower limit.  L1 further discloses determining if a threshold isn’t high (i.e. below the high value) and is in the correct( normal/mid value).]
(Claim 10)  Determine the torque across the power gearbox is less than or equal to the upper torque threshold; and
Determine the torque across the power gearbox is outside a normal operating range using the received data indicative of the torque across the power gearbox in response to determining the torque across the power gearbox is less than or equal to the upper torque threshold, and
Perform the at least one corrective action in response to determining the torque across the power gearbox is outside the normal operating range. [M1, Page 6, ¶58-62 discloses determining if the torque is within a desired range.  A desired range would be less than or equal to an upper limit, and further is normal if it above the lower limit, or is outside the normal operating if it is below the lower limit.  L1 further discloses determining if a threshold isn’t high (i.e. below the high value) and is in the correct( normal/mid value) or if it is not in the correct value but instead in low (Below the threshold). M1 and L1 both disclose performing a fuel reduction corrective action if the torque is measured LOW or under the system as it is below the anticipation range  and thus below the HIGH, upper range, and still not normal.]
In Re Claim 11:
R1 teaches:
The gas turbine engine of claim 6,wherein:
The fan comprises a fixed pitch fan; and [Figure 1 shows a normal fan without pitch change structure.]
The controller is configured to:
Receive data indicative of the torque across the power gearbox; [Page 9, ¶161-163 discloses the measuring of variables speed and reactionary torque to determine gearbox torque. Page 10, ¶164-165 discloses this information delivered to a processor.]
Determine the thrust across the power gearbox exceeds a normal operating range using the received data indicative of the torque across the power gearbox; [Page 10,¶166 discloses the thrust being lower or high.]
In response to determining that the torque across the power gearbox exceeds the normal operating range, determine the thrust across the power gearbox exceeds a lower thrust threshold using the received data indicative of the torque across the power gearbox; [Page 10, ¶166 discloses determining the thrust is low.]
In response to determining that the thrust across the power gearbox exceeds the lower thrust threshold, perform a first corrective action; [Page 10, ¶166 discloses decreasing fuel flow if the thrust is high.]
In response to determining that the thrust across the power gearbox exceeds the lower thrust threshold, perform a first corrective action; [Page 10, ¶166 discloses decreasing fuel flow if the thrust is high.]
R1 does not teach:
The system uses a variable pitch fan.  The controller is using a Torque lower outside the normal torque operating range to activate corrective actions as claimed.
M1 teaches:
Using torque measurements to determine control actions directly. [Fig. 8, elements 212-224.]  In particular if the torque outside the range (the examiner notes a ranges can have upper and lower limits given these are operational ranges as laid out in Page 6, ¶59) can determine actions such as reducing fuel supply. [Page 6, ¶62] As these torque values can indicate they are indicative of a failure of some part of the gearbox.[Page 6, ¶58-63.]  A particular exemplary condition is an under torque value (Page 6, ¶61-63.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 to include using the torque measurements directly to determine if the engine is outside an anticipated operational torque range, and to enact controls in response to reduce fuel supply, with the expectation of successfully reducing the change of damage to the engine during gearbox failures.] This would yield the limitation of the controller using a torque thresholds outside of normal operation to active the controller, and in particular the lower torque threshold triggering a corrective, such as fuel reduction.
R1 as modified by M1 does not explicitly disclose:
The torque thresholds include variable pitch fan and a second corrective action.
L1 teaches:
It is known to control a turbine(Figure 1, 10) with a fan, to utilize Torque thresholds to determine controlled actions with regards to fuel.  In particular measuring torque across the engine (Col. 9, ll. 20-40.] and determining if a Torque is a mid-level (correct), and not in an upper level (Torque High) or lower level (Torque Low), in various operating conditions (A, correct//C, High, and G or J//LOW) when combined with speed measurements, to enact either normal operation, (Correct or mid-level torque)  or to reduce the fuel (high or low torque conditions C and G). [Col. 10, ll. 45-59m  for operation A.  Col. 12, ll. 65 – Col., 13, l. 17 for operation C, upper torque threshold, Col. 14, ll. 10-23, and Col. 14, ll. 56-70 for operations G, and J for low torque threshold variants.  C and G also disclose reducing fuel supply.]  These control values are utilized because Torque is related to thrust, and a more efficient operation of the engine can be operated by regulating fuel flow by torque to satisfy recognized in the art desirable operational requirements of torque and engine speed. [Col. 1, ll. 5-46, Col. 2, ll. 10-37.] Further the system notes it can be desirable to utilize a variable pitch fan, to expand the flight conditions it can operate well under. [Col. 1, ll. 47-55.] Also during High Torque threshold condition, can also involve changing the fan/propeller pitch. [Col. 12, line 65 – Col. 13, line 17.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 and M1, to use the preexisting torque and speed monitoring, sensors and controllers of those systems, with the controller recognizing the thresholds and operational states as taught by L1 and further include a variable pitch propeller and pitch controls during high torque as further taught by L1, with the expectation of successfully improving keeping the engine operating in a desirable and efficient operational requirement of torque and engine speed.[Col. 1, ll. 5-46, Col. 2, l. 10-37.]  Further this would provide the expectation of successfully improving the fan operating flight conditions with variable pitch and pitch controls. [Col. 1, ll. 47-55, Col. 12, line 65 – Col. 13, line 17.] This would yield the limitation of the controller reducing the fuel supply during upper Torque threshold limit exceeding during certain engine speed conditions.  This would yield the limitation of reducing the supply of fuel to the gas turbine engine in response to determining the torque across the power gearbox exceeds the upper torque threshold.  This would further yield the limitation of the system including a variable pitch fan.
In Re Claims 12-18:
R1 as modified by M1 and L1 would teach:
The gas turbine engine of claim 11, wherein:
M1 and L1 further teach:
(Claim 12) the first corrective action comprises adjusting a pitch of one or more blades of the fan, increasing a rotational speed of the fan, or both; and [L1 Col. 14, ll. 56 – 73 discloses adjusting pitch of the fan.]
The second corrective action comprises reducing the rotational speed of the fan, reducing  a flow of the fuel to the gas turbine engine, adjusting the pitch of the one or more blades of the fan to a failsafe speed schedule, adjusting a flow of bleed air from a working gas flow path of the gas turbine engine via a variable bleed valve, or a combination thereof. [M1, Page 6, ¶60-62 discloses under torque triggering fuel reduction when indicative of a shaft failure, separate form a lower threshold for normal operation such as L1 would perform.  L1, Col. 14, ll. 10-23 discloses low torque threshold triggering a fuel reduction in some conditions.]
(Claim 13) in response to determining that the torque across the power gearbox exceeds the lower torque threshold, the controller is further configured to:
Determine the torque across the power gearbox is less than or equal to a mid torque threshold; and
In response to determining the torque across the power gearbox is less than or equal to the mid torque threshold, determine the torque across the power gearbox is within the normal operating range.  [Per L1, Col. 10, ll. 45-72,  it is known to determine if the system is in the Correct Torque, i.e. the normal operation threshold, which can be a range of value it is equal to and thus equal to or less than.  M1 ¶58-62 discloses determining under torque and normal operating range, the normal operating range being the mid torque threshold.]
(Claim 14) claim 13, in response to determining the torque across the power gearbox is less than or equal to the mid torque threshold, the controller is further configured to:
Determine the torque across the power gearbox is outside the normal operating range;
Perform the first corrective action; [Per M1, ¶58-62 discloses determining the system it outside normal operating range which would be lower or greater than the mid-level normal operation threshold, and further less outside the normal operation, and under via under torque, and reducing fuel a corrective action. Per L1, L1 Col. 14, ll. 56 – 73 discloses adjusting pitch of the fan, when it is below the Correct Torque threshold, and outside Correct operation range (normal) and thus low. This corrective action is a pitch change per claim 12, that is the first corrective action.]
Determining the torque across the power gearbox is less than or equal to the mid-torque threshold; and
In response to determining the torque across the power gearbox is less than or equal to the mid-torque threshold, determine the torque across the power gearbox is within the normal operating range.  [Per both M1 and L1 as discussed above in this claim section it is possible to determine the torque is equal to the normal operation range or equal to  CORRECT, either way this results in the torque being equal to or lower than the mid-level threshold, and within normal operating range.]
(Claim 15) claim 13, determine the torque across the power gearbox exceeds the mid torque threshold; and
In response to the torque across the power gearbox exceeding the mid-torque threshold,
Perform the second corrective action, [L1 Col. 12, ll. 65- Col. 13, ll. 18 discloses fuel reduction (second corrective action) and pitch change in response to a Torque High, which is a torque exceeding the mid-torque threshold.]
Determine the torque across the power gearbox is less than or equal to an upper torque threshold, and
`	in response to the torque across the power gearbox being less than or equal to the upper torque threshold, determine the torque across the power gearbox is within the normal operating range.    [Per L1, Col. 10, ll. 45-72,  it is known to determine if the system is in the Correct Torque, i.e. the normal operation threshold, which is less than or equal to an upper torque threshold (below HIGH) and  can be a range of value it is equal to and thus equal to or less than.  M1 ¶58-62 discloses determining torque outside an operational range, i.e. less than the upper torque threshold marking the upper normal range limit.]
(Claim 16) in response to determining that the torque across the power gearbox is less than or equal to the lower torque threshold and performing the second corrective action, the controller is further configured to:
Determining the torque across the power gearbox is less than or equal torque threshold; and
in response to the torque across the power gearbox is less than or equal to the upper torque threshold; determine the determine the torque across the power gearbox is within a normal operating. [It is possible after a first corrective action, to reexamine the system and make a new torque determination as both L1 and M1 show constant monitoring of the system.  And Per L1, Col. 10, ll. 45-72,  it is known to determine if the system is in the Correct Torque, i.e. the normal operation threshold, which is less than or equal to an upper torque threshold (below HIGH) and  can be a range of value it is equal to and thus equal to or less than.  M1 ¶58-62 discloses determining torque outside an operational range, i.e. less than the upper torque threshold marking the upper normal range limit.]
(Claim 17) claim 16, the controller is further configured to:
Determine the torque across the power gearbox exceeds the upper torque threshold; and
In response to the torque across the power gearbox exceeding the upper torque threshold, reduce a flow of fuel to the gas turbine engine. [Per L1, Col. 12, ll. 65 – Col. 13, ll. 18 discloses a Torque HIGH, as in above the upper torque threshold, and reduce the fuel.   M1 ¶58-62 discloses determining torque outside an operational range, i.e. less than the upper torque threshold marking the upper normal range limit and reducing the fuel.]
In Re Claim 19:
R1 teaches:
A method for a gas turbine engine including a fan section(Fig. 2, 23) comprising a fan(23) rotatable with a fan shaft(25), a turbomachinery section(Fig. 1, 19) comprising a turbine(19) and a turbomachine shaft(26) rotatable with the turbine, and a power gearbox(Fig. 2, 30) coupled to the fan shaft and the turbomachine shaft such that the fan shaft, the method comprising:
Determining, using data indicative of a torque across the power gearbox, [Page 9, ¶161-163 discloses the measuring of variables speed and reactionary torque to determine gearbox torque. Page 10, ¶164-165 discloses this information delivered to a processor.]
Determine the thrust across the power gearbox exceeds a lower thrust threshold using the received data indicative of the torque across the power gearbox; [Page 10,¶166 discloses the thrust being lower or high.]
Perform at least one corrective action in response to determining the thrust across the power gearbox exceeds the lower thrust threshold; [Page 10, ¶166 discloses increasing fuel flow if the thrust is low.]
Determine the thrust across the power gearbox exceeds an upper thrust threshold using the received data indicative of the torque across the power gearbox; [Page 10,¶166 discloses the thrust being lower or high.]
Reduce a supply of fuel to the gas turbine engine in response to determining the thrust across the power gearbox exceeds the upper thrust threshold; [Page 10, ¶166 discloses decreasing fuel flow if the thrust is high.]
R1 does not teach:
The controller is using a Torque upper threshold and a torque lower threshold to activate control actions as claimed.
M1 teaches:
Using torque measurements to determine control actions directly. [Fig. 8, elements 212-224.]  In particular if the torque outside the range (the examiner notes a ranges can have upper and lower limits given these are operational ranges as laid out in Page 6, ¶59) can determine actions such as reducing fuel supply. [Page 6, ¶62] As these torque values can indicate they are indicative of a failure of some part of the gearbox.[Page 6, ¶58-63.]  A particular exemplary condition is an under torque value (Page 6, ¶61-63.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 to include using the torque measurements directly to determine if the engine is outside an anticipated operational torque range, and to enact controls in response to reduce fuel supply, with the expectation of successfully reducing the change of damage to the engine during gearbox failures.] This would yield the limitation of the controller using a torque thresholds to active the controller, and in particular the lower torque threshold triggering a control action, such as fuel reduction.
R1 as modified by M1 does not explicitly disclose:
The torque thresholds includes an upper torque threshold to active the reduction of the fuel supply.
L1 teaches:
It is known to control a turbine(Figure 1, 10) with a fan, to utilize Torque thresholds to determine controlled actions with regards to fuel.  In particular measuring torque across the engine (Col. 9, ll. 20-40.] and determining if a Torque is a mid-level (correct), and not in an upper level (Torque High) or lower level (Torque Low), in various operating conditions (A, correct//C, High, and G//LOW) when combined with speed measurements, to enact either normal operation, (Correct or mid-level torque)  or to reduce the fuel (high or low torque conditions C and G). [Col. 10, ll. 45-59m  for operation A.  Col. 12, ll. 65 – Col., 13, l. 17 for operation C, upper torque threshold, and Col. 14, ll. 10-23, for operation G, lower Torque threshold.  C and G also disclose reducing fuel supply.]  These control values are utilized because Torque is related to thrust, and a more efficient operation of the engine can be operated by regulating fuel flow by torque to satisfy recognized in the art desirable operational requirements of torque and engine speed. [Col. 1, ll. 5-46, Col. 2, ll. 10-37.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 and M1, to use the preexisting torque and speed monitoring, sensors and controllers of those systems, with the controller recognizing the thresholds and operational states as taught by L1 with the expectation of successfully improving keeping the engine operating in a desirable and efficient operational requirement of torque and engine speed. This would yield the limitation of the controller reducing the fuel supply during upper Torque threshold limit exceeding during certain engine speed conditions.[Col. 1, ll. 5-46, Col. 2, ll. 10-37.]  This would yield the limitation of reducing the supply of fuel to the gas turbine engine in response to determining the torque across the power gearbox exceeds the upper torque threshold.
In Re Claim 20:
R1 as modified by L1 and M1 teaches:
R1 further teaches:
The method of claim 19, wherein receiving data indicative of the torque across the power gearbox comprises:
Receiving data indicative of the torque across the power gearbox from a gearbox sensor of a torque monitoring system, the gearbox senor coupled to a grounded structure (R1, Fig. 2, 24) of the gas turbine engine, the grounded st4ructure coupled to and supporting the power gearbox. (30). [Per Page 9, ¶161-Page 10, ¶166 discloses detecting a torque on the carrier/grounded structure, to determine the torque of the inlet and outlet shafts.  Page 6, ¶129-130 discloses the generic fan/turbine/gearbox structures, shafts, and static structure.]
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over R1 in view of M1 and L1 as applied to claim 11 above, and further in view of US 2011/0229319 to Bacic et al. (B1).
Claim 18:
R1 as modified by M1 and L1 teaches:
The gas turbine engine of claim 16, wherein:
The controller is further configured to:
Determine the torque across the power gearbox is outside the normal operating range; and
In response to determining the torque across the power gearbox is outside the normal operating range, [M1, Page 6, ¶58-62 discloses determining if the torque is outside a desired range.  L1 in the rejection of claim 11 is cited for showing several ranges of HIGH or LOW Torque outside a desired CORRECT range.]
Reduce a rotational speed of the fan, reduce a flow of fuel to the gas turbine engine, or both reduce the rotational speed of the fan and reduce the flow of fuel to the gas turbine engine, [M1 Page 6, ¶58-62 discloses an under torque outside a desirable range results in fuel reduction. L1 discloses per the cited operations in claim 11, multiple fuel reduction schedules for outside of the normal operation such as TORQUE High, operation A, and TORQUE Low, operation G.]
Adjust a pitch of one or more blades of the fan, [L1 discloses per the cited operations in claim 11, an operation A and an operation D, F, and J which disclose adjusting pitch of the blade.]
Determine the torque across the power gearbox is less than or equal to the upper torque threshold, and [Both L1 and M1 disclose a system that is constantly monitoring, thus after the corrective actions above, is able to monitor and detect additional new torque states.]
In response to the torque across the power gearbox being less than or equal to the upper torque threshold, determine the torque across the power gearbox is healthy.   [M1 disclose a normal operating range, (i.e. healthy, which would be below the upper threshold limit.) in the citations of claim 11.  Similarly L1 discloses on Col. 10, line 45-75 a correct or normal torque operation, which is below the Torque High.]
R1 as modified by M1 and L1 does not teach:
Wherein the pitch adjustment corresponds to a failsafe speed schedule
B1 teaches:
It is known to provide a fail-safe provision target blade pitch setting when the controller is unable to provide controls due to transmission errors, this schedule can be applied in the event the transmission fails. [Page 3, ¶30-32.]
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of R1 and L1, to include a fail-safe pitch schedule as taught by B1, with the expectation of successfully providing such a schedule to control pitch blade operations during abnormal operation or as an emergency operation state. [Page 3, ¶30-32.] This would yield during abnormal operation or a disturbed transmission, the pitch adjustment being a failsafe speed schedule.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 2022/0349318 to Nowoisky et al. teaches Torque sensors (Page 7, ¶122-138) for controlling a system with epicyclic gearbox and continues torque monitoring to determine signals outside of base lien operation and activate controller responses. It discloses continuous monitoring, iterative monitoring, and observing normal action to build a model of responses and controls.


NEXT OFFICE ACTION: Notice of Allowance
Notice of Pre-AIA  or AIA  Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Reasons for Allowance
The following is an examiner’s statement of reasons for allowance: Examiner refers Applicant to Interview summary in the IFW under January 12, 2025. Examiner noted the current amendment overcame the prior art.  Further, per a consideration of the art, the amendment overcomes any prior art suitable for modifying Razaket (R1) or Moniz(M1) and Lee(L1) given that while measurements are made in some references (R1 and M1) and controls based on various levels are made in (L1) they do not coordinate with the fuel and torque control such that it makes a model torque and based on the received data, utilizes said model torque to perform the function.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee.  Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion

CITED REFERENCE SUMMARIES: Ref US20220349318A1: Claims:
A method for detecting a functional failure in a power gearbox, in particular an epicyclic gearbox in an aircraft gas turbine engine comprising a) measuring operational data in the gas turbine engine of least one, in particular at least two operational parameters dependent on the power generation and power consumption of the gas turbine engine and/or the power gearbox, b) obtaining analyzed operational data comprising time data, angular data of a rotation, frequency data and/or phase data from the measured operational data, c) using the analyzed operational data in a comparison with stored baseline operational data to determine deviation data from the baseline operational data, d) determining time dependent trend data from the deviation data and/or determining at least a first state measured dependent on the power generation, the power consumption or the power regulation of the gas turbine engine and measuring at least a second state measured dependent on vibrational data of the gas turbine engine, and e) generating a signal and/or a protocol for controlling the epicyclic power gearbox and/or the gas turbine engine based on the time dependent trend data or based on the at least one first state and the at least one second state, in particular if a predetermined condition or threshold is exceeded.
a) measuring operational data in the gas turbine engine of least one, in particular at least two operational parameters dependent on the power generation and power consumption of the gas turbine engine and/or the power gearbox,
b) obtaining analyzed operational data comprising time data, angular data of a rotation, frequency data and/or phase data from the measured operational data,
c) using the analyzed operational data in a comparison with stored baseline operational data to determine deviation data from the baseline operational data,
d) determining time dependent trend data from the deviation data and/or determining at least a first state measured dependent on the power generation, the power consumption or the power regulation of the gas turbine engine and measuring at least a second state measured dependent on vibrational data of the gas turbine engine, and
e) generating a signal and/or a protocol for controlling the epicyclic power gearbox and/or the gas turbine engine based on the time dependent trend data or based on the at least one first state and the at least one second state, in particular if a predetermined condition or threshold is exceeded.
The method according to claim 1 , wherein at least one measured operational parameter and/or at least one baseline operational parameter is a torque at a shaft, a torque at the power gearbox, epicyclic gearbox, a tangential torque at the power gearbox, in particular the epicyclic gearbox, a rotational speed of the shaft, a rotational speed at the input and/or output side of the power gearbox, in particular of the epicyclic gearbox, a power loss over the input and output side of the power gearbox, in particular the epicyclic gearbox, speed of the aircraft, vibrational data at the power gearbox, in particular the epicyclic gearbox, fuel intake of the gas turbine engine, a temperature, in particular in the core of the gas turbine engine and/or at the exit of a combustion chamber, a temperature in the feed and/or scavenge oil temperature of the power gearbox, in particular the epicyclic gearbox, a position and/or a movement of a variable guide vane in the gas turbine engine, a pressure in the gas turbine engine, a deviation from the nominal in at least one of the above parameters.
a torque at a shaft,
a torque at the power gearbox, epicyclic gearbox,
a tangential torque at the power gearbox, in particular the epicyclic gearbox,
a rotational speed of the shaft,
a rotational speed at the input and/or output side of the power gearbox, in particular of the epicyclic gearbox,
a power loss over the input and output side of the power gearbox, in particular the epicyclic gearbox,
speed of the aircraft,
vibrational data at the power gearbox, in particular the epicyclic gearbox,
fuel intake of the gas turbine engine,
a temperature, in particular in the core of the gas turbine engine and/or at the exit of a combustion chamber,
a temperature in the feed and/or scavenge oil temperature of the power gearbox, in particular the epicyclic gearbox,
a position and/or a movement of a variable guide vane in the gas turbine engine,
a pressure in the gas turbine engine,
a deviation from the nominal in at least one of the above parameters.
The method of claim 1 , wherein the time data obtained from the measured operational data is subjected to windowing in signal processing unit.
The method of claim 1 , wherein the deviation data comprises a change in magnitude of an amplitude and/or a change in the phase.
The method of claim 1 , wherein the time dependent deviation data comprises data on at least one rotational speed of a shaft, at least one radial, axial and/or tangential dynamic load indicator, at least one radial, axial and/or tangential vibration.
at least one rotational speed of a shaft,
at least one radial, axial and/or tangential dynamic load indicator,
at least one radial, axial and/or tangential vibration.
The method of claim 1 , wherein the trend data is checked if a condition or threshold is exceed for at least a trend in a radial, axial and/or tangential vibration, a trend in a radial, axial and/or tangential dynamic load indicators, a trend in speed, in particular speed fluctuations.
a trend in a radial, axial and/or tangential vibration,
a trend in a radial, axial and/or tangential dynamic load indicators,
a trend in speed, in particular speed fluctuations.
The method of claim 6 , wherein the threshold is adapted for range of operation points by the use of Ã¡ priori knowledge, in particular that known magnitudes of harmonics which are not related to a failure are considered in filtering out relevant harmonics for the failure.
The method of claim 1 , wherein the signal and/or the protocol is used for indicating a functional failure of a bearing, in particular a ball bearing or a journal bearing in the power gearbox, in particular in the epicyclic gearbox, the ring gear, planet carrier, the sun gear and/or the planet gears.
The method of claim 1 , wherein the signal and/or the protocol is used for generating a lifetime prediction and/or a maintenance schedule for the power gearbox, in particular the epicyclic gearbox and/or the gas turbine engine.
The method of claim 1 , wherein signal and/or protocol is triggered when the measured operational data comprises vibrational frequencies of more than 500 Hz, in particular more than 5000 Hz.
The method of claim 1 , wherein the measured operational data is obtained from at least one power sensor, fuel flow sensor, torque sensor, rotational speed sensor, speed sensor, vibration sensor, temperature sensor and/or pressure sensor.
The method of claim 11 , wherein at least one sensor is positioned at a static part of the power gearbox, in particular the epicyclic gearbox, in particular at housing of the epicyclic gearbox, a ring gear of the epicyclic gearbox and/or the ring gear mount of the epicyclic gearbox.
The method of claim 1 , wherein the epicyclic gearbox comprises planetary gears in a star arrangement or in a planetary arrangement.
The method of claim 1 , with a detection of a vibration signature within a predetermined frequency range, a determination of a property of the vibration signature based on the signals at different points in time and a generation of a command or signal based on a comparison of the property of the vibration signature with a predetermined threshold.
A system for detecting a functional failure in an power gearbox, in particular an epicyclic gearbox in an aircraft gas turbine engine comprising at least one sensor measuring operational dataI in the gas turbine engine of least two operational parameters dependent on the power generation and/or power consumption of the gas turbine engine and the power gearbox, in particular the epicyclic gearbox, computing means for obtaining analyzed operational data comprising time data, angular data of a rotation, frequency data and/or phase data from the measured operational data and for using the analyzed operational data in a comparison with stored baseline operational data to determine deviation data from the baseline operational data, trend computing means for determining time dependent trend data from the deviation data and/or means for determining at least a first state measured dependent on the power generation, the power consumption or the power regulation of the gas turbine engine and measuring at least a second state measured dependent on vibrational data of the gas turbine engine, and signal and/or a protocol generation means for controlling the power gearbox, in particular the epicyclic gearbox and/or the gas turbine engine based on the time dependent trend in the deviation data or based on the at least one first state and the at least one second state.
at least one sensor measuring operational dataI in the gas turbine engine of least two operational parameters dependent on the power generation and/or power consumption of the gas turbine engine and the power gearbox, in particular the epicyclic gearbox,
computing means for obtaining analyzed operational data comprising time data, angular data of a rotation, frequency data and/or phase data from the measured operational data and for using the analyzed operational data in a comparison with stored baseline operational data to determine deviation data from the baseline operational data,
trend computing means for determining time dependent trend data from the deviation data and/or means for determining at least a first state measured dependent on the power generation, the power consumption or the power regulation of the gas turbine engine and measuring at least a second state measured dependent on vibrational data of the gas turbine engine, and
signal and/or a protocol generation means for controlling the power gearbox, in particular the epicyclic gearbox and/or the gas turbine engine based on the time dependent trend in the deviation data or based on the at least one first state and the at least one second state.
A gas turbine engine for an aircraft comprising: an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a power gearbox, in particular an epicyclic gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, with a system for detecting a failure of the power gearbox, in particular the epicyclic gearbox with the features of claim 15 .
an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor;
a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and
a power gearbox, in particular an epicyclic gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, with a system for detecting a failure of the power gearbox, in particular the epicyclic gearbox with the features of claim 15 .
Ref US20200088595A1: Claims:
An apparatus for measuring the thrust of a gas turbine engine for an aircraft, the gas turbine engine comprising: an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, wherein: the gearbox comprising a sun gear, a plurality of planet gears, an annulus gear and a planet carrier, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, each planet gear being rotatably mounted on the planet carrier, the core shaft being arranged to drive the sun gear and one of the planet carrier and the annulus gear being arranged to drive the fan via a fan shaft, the other one of the annulus gear and the planet carrier being mounted in a static structure, the static structure being arranged to restrain rotational movement of the other one of the annulus gear and the planet carrier, the apparatus for measuring the thrust of a gas turbine engine for an aircraft comprising: at least one force sensor to measure the force applied by the other one of the annulus gear and the planet carrier on the static structure, a first rotational speed sensor arranged to measure the rotational speed of the core shaft, a second rotational speed sensor arranged to measure the rotational speed of the fan shaft, a processor arranged to receive the measurement of the force applied by the other one of the annulus gear and the planet carrier on the static structure, the processor being arranged to determine the restoring torque on the other one of the annulus gear and the planet carrier from the measurement of the force applied by the other one of the annulus gear and the planet carrier on the static structure, the processor arranged to receive the measurement of the rotational speed of the core shaft, the processor arranged to receive the measurement of the rotational speed of the fan shaft, the processor being arranged to determine the torque applied to the fan by the one of the planet carrier and the annulus gear using the rotational speed of the core shaft, the rotational speed of the fan shaft and the restoring torque on the other one of the annulus gear and the planet carrier, the processor being arranged to determine the thrust of the fan from the torque applied to the fan and the rotational speed of the fan.
an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor;
a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and
a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, wherein:
the gearbox comprising a sun gear, a plurality of planet gears, an annulus gear and a planet carrier, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, each planet gear being rotatably mounted on the planet carrier, the core shaft being arranged to drive the sun gear and one of the planet carrier and the annulus gear being arranged to drive the fan via a fan shaft,
the other one of the annulus gear and the planet carrier being mounted in a static structure, the static structure being arranged to restrain rotational movement of the other one of the annulus gear and the planet carrier,
the apparatus for measuring the thrust of a gas turbine engine for an aircraft comprising:
at least one force sensor to measure the force applied by the other one of the annulus gear and the planet carrier on the static structure,
a first rotational speed sensor arranged to measure the rotational speed of the core shaft,
a second rotational speed sensor arranged to measure the rotational speed of the fan shaft,
a processor arranged to receive the measurement of the force applied by the other one of the annulus gear and the planet carrier on the static structure, the processor being arranged to determine the restoring torque on the other one of the annulus gear and the planet carrier from the measurement of the force applied by the other one of the annulus gear and the planet carrier on the static structure, the processor arranged to receive the measurement of the rotational speed of the core shaft, the processor arranged to receive the measurement of the rotational speed of the fan shaft, the processor being arranged to determine the torque applied to the fan by the one of the planet carrier and the annulus gear using the rotational speed of the core shaft, the rotational speed of the fan shaft and the restoring torque on the other one of the annulus gear and the planet carrier,
the processor being arranged to determine the thrust of the fan from the torque applied to the fan and the rotational speed of the fan.
The apparatus of claim 1 , wherein the turbine is a first turbine, the compressor is a first compressor, and the core shaft is a first core shaft; the engine core further comprises a second turbine, a second compressor, and a second core shaft connecting the second turbine to the second compressor; and the second turbine, second compressor, and second core shaft are arranged to rotate at a higher rotational speed than the first core shaft.
the engine core further comprises a second turbine, a second compressor, and a second core shaft connecting the second turbine to the second compressor; and
the second turbine, second compressor, and second core shaft are arranged to rotate at a higher rotational speed than the first core shaft.
The apparatus of claim 1 , wherein the planet carrier being arranged to drive the fan via the fan shaft, the annulus gear being mounted in the static structure, the static structure being arranged to restrain rotational movement of the annulus gear, the at least one force sensor to measure the force applied by the annulus gear on the static structure, the processor arranged to receive the measurement of the force applied by the annulus gear on the static structure, the processor being arranged to determine the restoring torque on the annulus gear from the measurement of the force applied by the annulus gear on the static structure, the processor being arranged to determine the torque applied to the fan by the planet carrier using the rotational speed of the core shaft, the rotational speed of the fan shaft and the restoring torque on the annulus gear.
the annulus gear being mounted in the static structure, the static structure being arranged to restrain rotational movement of the annulus gear,
the at least one force sensor to measure the force applied by the annulus gear on the static structure,
the processor arranged to receive the measurement of the force applied by the annulus gear on the static structure, the processor being arranged to determine the restoring torque on the annulus gear from the measurement of the force applied by the annulus gear on the static structure, the processor being arranged to determine the torque applied to the fan by the planet carrier using the rotational speed of the core shaft, the rotational speed of the fan shaft and the restoring torque on the annulus gear.
The apparatus of claim 1 , wherein the annulus gear being arranged to drive the fan via the fan shaft, the planet carrier being mounted in the static structure, the static structure being arranged to restrain rotational movement of the planet carrier, the at least one force sensor to measure the force applied by the planet carrier on the static structure, a processor arranged to receive the measurement of the force applied by the planet carrier on the static structure, the processor being arranged to determine the restoring torque on the planet carrier from the measurement of the force applied by the planet carrier on the static structure, the processor being arranged to determine the torque applied to the fan by the annulus gear using the rotational speed of the core shaft, the rotational speed of the fan shaft and the restoring torque on the planet carrier.
the planet carrier being mounted in the static structure, the static structure being arranged to restrain rotational movement of the planet carrier,
the at least one force sensor to measure the force applied by the planet carrier on the static structure,
a processor arranged to receive the measurement of the force
[Truncated to input limit]