Eccentric slot for epicyclic gear train

Abstract

A gear case for a gas turbine engine. The gear case includes a rotor and a sump. An oil system is configured to supply oil to the gear case. The rotor is rotatable about an axis of rotation. The rotor expels oil radially outward when the rotor is rotated. The sump is positioned radially outward of the rotor to collect oil expelled by the rotor when the rotor is rotated. The sump is positioned eccentrically relative to the rotor.

Description

Technical Field

[0001] This disclosure relates to oil tanks for revolving gear systems, and more particularly, to oil tanks for revolving gear systems used in gas turbine engines for aircraft. Background Technology

[0002] Oil is used in power gearboxes (e.g., power gearboxes that include planetary gear trains) to lubricate the gears and bearings within the gearbox. In planetary gear trains, oil can be supplied to lubricate the meshing between the gears. As the gears in a planetary gear train rotate during operation, the oil is expelled outward by inertial (or centrifugal) force. The oil can be collected by grooves located radially outward of the gears. Attached Figure Description

[0003] The features and advantages of this disclosure will become apparent from the following description of various exemplary embodiments, as illustrated in the accompanying drawings, wherein similar reference numerals generally denote the same, functionally similar, and / or structurally similar elements.

[0004] Figure 1 This is a cross-sectional view of a turbofan engine using a gearbox according to an embodiment of the present disclosure.

[0005] Figure 2 A turboprop engine using a gearbox according to an embodiment of the present disclosure is shown.

[0006] Figure 3 It is along Figure 1 The line 3-3 in the middle is cut off Figure 1 The gearbox shown is a three-dimensional cross-sectional view.

[0007] Figure 4 yes Figure 3 The diagram shows the arrangement of the rotor and oil tank of the gearbox.

[0008] Figure 5 yes Figure 4 Another schematic diagram showing the arrangement of the rotor and oil tank.

[0009] Figure 6 yes Figure 3 The diagram shows the arrangement of the rotor of the gearbox and another oil tank.

[0010] Figure 7 yes Figure 3 The diagram shows the arrangement of the rotor of the gearbox and another oil tank.

[0011] Figure 8 yes Figure 3 The diagram shows the arrangement of the gearbox rotor, another oil tank, and the housing. Detailed Implementation

[0012] The features, advantages, and embodiments of this disclosure will be set forth or apparent from consideration of the following detailed description, accompanying drawings, and claims. Furthermore, it should be understood that the following detailed description is exemplary and intended to provide further explanation without limiting the scope of the claimed disclosure.

[0013] Various embodiments are discussed in detail below. Although specific embodiments are discussed, they are for illustrative purposes only. Those skilled in the art will recognize that other components and constructions can be used without departing from the spirit and scope of this disclosure.

[0014] As described above, oil used to lubricate the gears of a planetary gear train can be discharged radially outward and collected in a groove. The groove can be circular and surrounds the gears of the planetary gear train, such that the groove is located radially outward of the gears. The oil collected in the groove can be removed at a clean port. The amount of oil in the groove varies based on the circumferential position. The amount of oil in the groove is least just after the clean port relative to the rotation direction of the rotor of the planetary gear train (e.g., a planetary gear unit), and then increases to the clean port in the rotation direction of the rotor. This accumulation of oil in the groove can cause wind resistance loss and oil turbulence in the rotor. The groove size can be designed based on the volume of maximum oil volume to avoid this loss and turbulence. Based on this standard design size, the size of the groove and the overall size of the gearbox can be increased, and an additional distance can be left between the rotor and the groove at the location where the oil volume in the groove is less. Instead of positioning the groove concentrically with the planetary gear train, in the embodiments discussed herein, the center of the groove is positioned eccentrically with respect to the rotation center of the planetary gear train. In these embodiments, the surface level of the oil in the groove is more evenly spaced from the rotor over the entire circumference of the groove. Maintaining a uniform distance between the oil and the rotor, keeping the distance to a minimum, avoids oil agitation and wind resistance loss. However, space is saved and the overall size of the gearbox is reduced by eliminating the oil surface level and the large distance between the rotor, which is unnecessary but would result in extra space in the concentric groove design.

[0015] The slot design discussed in this article is applicable to gearboxes used in aircraft engines (especially gas turbine engines). Figure 1 and Figure 2 Two gas turbine engines that can be used to propel an aircraft are shown. Figure 1 The gas turbine engine shown is a high-bypass turbofan engine 100. Figure 2The gas turbine engine shown is a turboprop engine 102. Both the turbofan engine 100 and the turboprop engine 102 include a gearbox 200 with an eccentric slot 250 according to this disclosure, which will be discussed further below. Although the following description relates to the turbofan engine 100 and / or the turboprop engine 102, this disclosure is also applicable to wind turbines and turbomachinery, generally including, for example, propeller fan gas turbine engines, turbojet gas turbine engines, and turbine shaft gas turbine engines, including marine turbine engines, industrial turbine engines, and auxiliary power units. Furthermore, the eccentric slot arrangement can be used in any suitable gearbox, including those with a planetary gear train.

[0016] like Figure 1 As shown, the turbofan engine 100 has an axial direction A (extending parallel to the longitudinal centerline 104), a radial direction R, and a circumferential direction. The circumferential direction ( Figure 1 (Not depicted) extends in a direction of rotation about a longitudinal centerline 104. The turbofan engine 100 may include an engine core 106 (also referred to as a turbine) and a fan assembly 140. The engine core 106 may typically include a compressor section 110, a combustion section 120, and a turbine section 130 arranged in a series flow configuration. The compressor section 110 may define one or more compressors, such as a low-pressure compressor 112 and a high-pressure compressor 114. The turbine section 130 may define one or more turbines, such as a high-pressure turbine 132 and a low-pressure turbine 134. In various embodiments, the compressor section 110 may also include an intermediate-pressure compressor. In other embodiments, the turbine section 130 may also include an intermediate-pressure turbine. In wind turbine applications, the engine core 106 may typically be defined as one or more generators.

[0017] The low-pressure compressor 112 and high-pressure compressor 114 in compressor section 110, and the high-pressure turbine 132 and low-pressure turbine 134 in turbine section 130, may each include one or more rotors. In one embodiment, the rotor includes one or more shafts connecting compressor section 110 to turbofan engine 100 of turbine section 130. In other embodiments, the rotor typically defines a disk extending at least partially in a radial direction R and a plurality of airfoils arranged circumferentially adjacent to each other and extending outward from the disk in the radial direction R. In one embodiment, one or more rotors may be individually connected together. For example, each rotor of turbine section 130 or compressor section 110 may be connected by mechanical fasteners (e.g., bolts, nuts, screws, and / or rivets) or by a joining process (e.g., welding, friction joining, diffusion joining, etc.). In various embodiments, one or more compressors of compressor section 110 may be connected to and rotate with one or more turbine drives of turbine section 130 via one or more shafts. For example, the rotor of the low-pressure compressor 112 can be connected to and driven by the rotor of the low-pressure turbine 134 via the low-pressure shaft 122, and the rotor of the high-pressure compressor 114 can be connected to and driven by the rotor of the high-pressure turbine 132 via the high-pressure shaft 124.

[0018] Fan assembly 140 typically includes a fan rotor 142. The fan rotor 142 includes a plurality of blades 144 coupled to the fan rotor 142 and extending outwardly from the fan rotor 142 in a radial direction R. Figure 1 In the illustrated embodiment, the fan rotor 142 may extend in the axial direction A from the reduction gearbox or power gearbox 200 (referred to herein as "gearbox 200") toward the front end. The fan assembly 140 also includes a coupling shaft 126, which is coupled to the gearbox 200 and extends toward the rear end of the turbofan engine 100. The coupling shaft 126 may couple the engine core 106 to the gearbox 200.

[0019] like Figures 1 to 3As shown, the gearbox 200 of this embodiment includes a planetary gear train 202, which includes a sun gear 210 and a plurality of planetary gears 222. The sun gear 210 is axially mounted to and concentrically attached to a connecting shaft 126, such that the sun gear 210 is attached to or integral with the connecting shaft 126. As will be discussed further below, the sun gear 210 is driven by an engine core 106 (receiving torque from the engine core 106) to rotate about a rotation axis 212, which in this embodiment coincides with a longitudinal centerline 104. The sun gear 210 includes a plurality of teeth that engage (or mesh with) a plurality of teeth formed on each of the plurality of planetary gears 222. A ring gear 230 (or annular gear) engages with and surrounds the plurality of planetary gears 222. More specifically, the ring gear 230 includes a plurality of teeth that engage (or mesh with) a plurality of teeth formed on each of the plurality of planetary gears 222.

[0020] In this embodiment, the ring gear 230 is stationary. The plurality of planetary gears 222 not only rotate about their respective axes of rotation 224, but also collectively rotate about the axis of rotation 212 of the sun gear 210. The planetary gears 222 are rotatably connected to a carrier 226, and the carrier 226 rotates about the axis of rotation 212 of the sun gear 210 as the plurality of planetary gears 222 rotate together. The plurality of planetary gears 222 can be rotatably connected to the carrier 226 via various bearings (e.g., roller, ball, or other bearing types, such as journal bearings). The carrier 226 is further connected to an output element to allow rotation and transmission of power and torque from the sun gear 210 through the plurality of planetary gears 222. For example, the carrier 226 can be coupled to or otherwise integrated with the fan rotor 142. Each of the plurality of planetary gears 222 engages with the sun gear 210 to rotate through the sun gear 210. Each planetary gear 222 is configured to receive power and torque from the sun gear 210.

[0021] In other embodiments, the plurality of planetary gears 222 may be fixed such that the axis of rotation 224 of each planetary gear 222 is fixed relative to the sun gear 210. In such an arrangement, the ring gear 230 rotates about the axis of rotation 212 of the sun gear 210 and is connected to an output element (e.g., fan rotor 142) to allow rotation and transmission of power and torque from the sun gear 210 through the plurality of planetary gears 222. The ring gear 230 engages with each of the plurality of planetary gears 222 to be rotated by the plurality of planetary gears 222. The ring gear 230 is configured to receive power and torque from the plurality of planetary gears 222. In various embodiments, the gearbox 200 may further include additional planetary gears radially disposed between the plurality of planetary gears 222 and the sun gear 210, or between the plurality of planetary gears 222 and the ring gear 230. The various gears may be of various suitable gear designs (e.g., helical gears), and in the case of the planetary gears 222, stepper gears may be included.

[0022] like Figure 1 As shown, coupling shaft 126 is connected to engine core 106 to transmit torque and power from engine core 106 to sun gear 210, and then to fan rotor 142 via planetary gear train 202. Fan rotor 142 may be connected to bracket 226 or ring gear 230 to receive torque from sun gear 210 and transmit torque to drive fan assembly 140. As power and torque are transmitted from engine core 106, gearbox 200 provides power and torque to fan rotor 142 at an output speed that is more appropriately adjusted for fan assembly 140. For example, gearbox 200 may reduce the speed of fan rotor 142 relative to engine core 106 by two times or more. According to one embodiment, gearbox 200 reduces the rotational speed from engine core 106 (e.g., compressor section 110 or turbine section 130) and provides the desired amount of torque and rotational speed to fan assembly 140.

[0023] During operation of the turbofan engine 100, a certain amount of air (inlet air 12), as schematically indicated by arrow 12, enters the turbofan engine 100. As the inlet air 12 passes through the fan blades 144, a portion of the air (bypass air 14), as schematically indicated by arrow 14, is directed or directed to the outside of the engine core 106 to provide propulsion. Additionally, another portion of the air, as schematically indicated by arrow 22 and referred to as core air 22, is directed or directed through the associated inlet 108 into the compressor section 110. The core air 22 is gradually compressed as it flows toward the combustion section 120 through the compressor section 110 (e.g., through the low-pressure compressor 112 and the high-pressure compressor 114). The now compressed air 24 (as schematically indicated by arrow 24) flows into the combustion section 120, where fuel is introduced, mixed with at least a portion of the compressed air 24, and ignited to form combustion gases 26. Combustion gas 26 flows into turbine section 130, causing the rotating components of turbine section 130 to rotate and supporting the operation of rotating components respectively connected in compressor section 110 and / or fan assembly 140, as discussed above.

[0024] As mentioned above, Figure 2 A turboprop engine 102 is shown, which may be equipped with a gearbox 200 having an eccentric slot arrangement. Figure 1 The discussion of the turbofan engine 100 shown also applies to Figure 2 The turboprop engine 102 is shown. Identical or similar components between the turbofan engine 100 and the turboprop engine 102 are referred to by the same reference numerals, and detailed descriptions of these components are omitted. Figure 2 In the arrangement shown, inlet 108 is located at the rear end of turboprop engine 102, and core air 22 flows in a forward direction. However, other arrangements of turboprop engine 102 may be used, in which inlet 108 is located at the front end of turboprop engine 102. Instead of fan assembly 140, turboprop engine 102 includes propeller assembly 150. Propeller assembly 150 includes a plurality of propeller blades 152, which are coupled to propeller shaft 154 and extend outward from propeller shaft 154 in a radial direction R. Similar to fan rotor 142, propeller shaft 154 is connected to gearbox 200 to receive torque and power from engine core 106 via planetary gear train 202. Propeller shaft 154 may be connected to planetary gear train 202 in a similar manner to fan rotor 142 discussed above.

[0025] Figure 3 This is a cross-sectional view of the gearbox 200 according to an embodiment. Figure 3 The cross-sectional view is along Figure 1The line 3-3 shown is cut off. As discussed above, gearbox 200 includes a planetary gear train 202 having a sun gear 210, a plurality of planetary gears 222 rotatably connected to a carrier 226, and a ring gear 230. Oil can be used to lubricate the rotating components of gearbox 200, including the sun gear 210, planetary gears 222, and ring gear 230. Oil system 240 is configured to supply oil to gearbox 200. In this embodiment, oil system 240 includes an oil pump 242 that draws oil from reservoir 244 (or oil collection tank). Oil pump 242 pressurizes and drives the oil flow to be injected by at least one oil nozzle 246. Oil can be injected downstream (in the direction of rotation) of the backlash formed between meshing (engaging) gears. Figure 3 As shown, for example, oil nozzle 246 is fluidly connected to reservoir 244 and is configured to inject oil into the tooth gap formed between one of the planetary gears 222 and the gear ring 230. Figure 3 Only one oil nozzle 246 is shown, but multiple oil nozzles 246 may be used, for example, at each tooth gap formed between the planetary gear 222 and the ring gear 230. The nozzle 246 is preferably located upstream of the tooth gap and injects oil in the direction toward the tooth gap. Oil may be supplied to the planetary gear train 202 using other suitable supply devices and at other locations, including, for example, the tooth gap formed between the planetary gear 222 and the sun gear 210.

[0026] As described above, the plurality of planetary gears 222 rotate together with the carrier 226 about the rotation axis 212 of the sun gear 210. The plurality of planetary gears 222 together with the carrier 226 may be referred to herein as rotor 220. For example, in a configuration where the gear ring 230 rotates about the rotation axis 212 of the sun gear 210 instead of the plurality of planetary gears 222, the gear ring 230 may be another example of a rotor. As the rotor 220 rotates about the rotation axis 212 of the sun gear 210, oil is discharged outward by inertial (or centrifugal) force and collected by the trough 250.

[0027] The slot 250 may be circular and surround the gears of the planetary gear train 202, such that the slot 250 is located radially outside the rotor 220, and more specifically, radially outside the plurality of planetary gears 222 and carrier 226. The slot 250 is also located radially outside the sun gear 210. The slot 250 is shown as being radially outside the gear ring 230, but in some embodiments, particularly when the gear ring 230 is stationary, the slot 250 may be integrally formed with the gear ring 230. In this embodiment, the slot 250 is shown as having a U-shape, but the slot 250 may have any shape suitable for collecting oil therein. The slot 250 includes a removal port 252. Oil collected in the slot 250 can be removed at the removal port 252. The removal port 252 is located at the bottom of the slot 250 so that gravity can help the oil flow to the removal port 252. The purge port 252 is fluidly connected to the reservoir 244, and oil is purged from the tank 250 and returned to the reservoir 244 through the purge port 252. Therefore, the reservoir 244 is configured to receive oil from the purge port 252.

[0028] As described above, in the concentric arrangement of slot 250 and rotor 220, the distance between slot 250 and rotor 220 is preferably designed based on the maximum oil volume in slot 250 to avoid the oil level approaching the rotor (e.g., gear ring). When the oil level rises to near the rotor, the oil may be severely disturbed and unintentionally picked up by the rotor. If the oil level continues to rise, part of the rotor rim may be immersed in the oil, resulting in increased resistance on the rotor and thus a large power loss. This phenomenon is called oil turbulence. To avoid oil turbulence, it is possible to increase the distance between the rotor and the slot, which increases the size of slot 250 and the overall size of gearbox 200, but leaves additional distance at locations where the oil volume in the slot is low between rotor 220 and slot 250. Instead of positioning the slot concentrically with the planetary gear train 202, slot 250 can be positioned eccentrically with the planetary gear train 202.

[0029] Figure 4 and Figure 5 This is a schematic diagram illustrating the eccentric groove 250 of this embodiment. The rotor 220 rotates in direction A about a rotation axis (in this embodiment, the rotation axis is the rotation axis 212 of the sun gear 210). As described above, the rotor 220 discharges oil outward toward the groove 250, such as from... Figure 4The rotor 220 is indicated by an arrow. As described above, the slot 250 collects the discharged oil, and the collected oil is removed through the cleaning port 252. As described above, the slot 250 is circular, having a center (slot center 254) and a radius (slot radius Rg). In some embodiments, the slot 250 may have a variable radius in the axial direction of the gearbox 200, and in these embodiments, the slot radius Rg may be the minimum radius of the slot 250 within the span of the width of the rotor 220. The rotor 220 also has a radius (rotor radius Rr). In some embodiments, the rotor 220 may have a variable radius across the width of the rotor 220. In these embodiments, the rotor radius Rr may be the maximum radius of the rotor 220 within the span of the width of the rotor 220, but the slot radius Rg and the rotor radius Rr should lie in the same cross-sectional plane within the span of the width of the rotor 220. In embodiments where the rotor 220 is a plurality of planetary gears 222 rotating together, the rotor radius Rr may be the maximum distance from the center of rotation to the edge of the rotating component. Note that the slot radius Rg is greater than the rotor radius Rr.

[0030] In the following discussion, the radial direction is the radial direction of the rotor taken from the rotation axis 212. Similarly, the angular position θ is taken relative to a reference position in the rotation direction. The reference position can be the center of the clearing port 252. When the clearing port 252 is not circular, the center of the clearing port 252 can be the center of the width of the port and located at the inner surface of the slot 250. The angular position θ of the reference position is zero. The angular position θ increases from zero in the rotation direction A, where the first quadrant is from zero to ninety degrees, the second quadrant is from ninety degrees to one hundred and eighty degrees, the third quadrant is from one hundred and eighty degrees to two hundred and seventy degrees, and the fourth quadrant is from two hundred and seventy degrees to three hundred and sixty degrees.

[0031] The slot 250 is eccentrically positioned relative to the rotor 220. In this embodiment, the slot 250 is positioned such that the rotor 220 is furthest from the slot 250 at an angular position θ with the most oil, but closer to the slot 250 at an angular position θ with less oil. The slot center 254 can be offset in the radial direction of the rotor 220. When the slot 250 is circular, the distance by which the slot center 254 is offset radially from the axis of rotation 212 is... Figure 5 The eccentricity (circle) e shown cir In the arrangement discussed above, the slot center 254 is preferably offset such that it lies in the fourth quadrant. The relative position of the slot center 254, with respect to the angular position θ, can be determined by the eccentricity angle. Given. Eccentric angle. Preferably, the angle is between 270 degrees and 360 degrees, and more preferably between 310 degrees and 350 degrees.

[0032] The position of the slot 250, and more specifically, the position of the slot center 254, can be characterized by the eccentricity ε given by equation (1).

[0033]

[0034] In equation (1), the eccentricity (circle) e cir It refers to the eccentricity (circle) discussed above, and the center gap (circle) C. cir It is the difference (C) between the slot radius Rg and the rotor radius Rr. cir =Rg – Rr). In other words, the eccentricity ε is the ratio of the eccentric distance e to the difference between the slot radius Rg and the rotor radius Rr. Based on experimental tests, the eccentricity ε is preferably from two to seventy-six per thousand, and more preferably from four to thirty-eight per thousand.

[0035] Figure 6 This is a schematic diagram illustrating another arrangement of slot 250. Figure 4 and Figure 5 In the illustrated embodiment, the groove 250 is circular, but the groove can have other shapes. The groove 250 can have, for example... Figure 6 The shape shown is an ellipse. In... Figure 6 In the groove shown, the groove center 254 is the center of the ellipse. Groove 250, and more specifically, the groove center 254 can be positioned similarly to the above regarding... Figure 4 and Figure 5 The slot 250 is offset in the manner discussed.

[0036] Figure 7 This is a schematic diagram illustrating yet another arrangement of slots 250. In this embodiment, the slots 250 have an irregular shape, wherein the distance G (gap G) between the rotor 220 and the slots 250 is variable (not constant) within 360 degrees (angular position θ) around the center (rotation axis 212) of the rotor 220. The distance from the center (rotation axis 212) of the rotor 220 to the slots 250 can also be variable (not constant) within 360 degrees (angular position θ) around the center (rotation axis 212) of the rotor 220. In some embodiments, the slot distance Dg is the distance from the center (rotation axis 212) of the rotor 220 to the slots 250 at a given angular position θ, and the gap G can be calculated as the difference between the slot distance Dg and the rotor radius Rr (G = Dg – Rr). In some embodiments, the gap G increases with increasing angular position θ. The slot distance Dg can have a maximum slot distance Dg. max and minimum slot distance Dg min .

[0037] The irregularly shaped groove 250 or the elliptical groove 250 can also have an eccentricity ε given by equation (2).

[0038]

[0039] In equation (2), the eccentric distance (irregularity) e irr Given by equation (3), and the center gap (irregularity) C irr It is given by equation (4).

[0040]

[0041]

[0042] Based on experimental testing, the eccentricity ε of the non-circular embodiment is preferably from 0.2% to 76%, and more preferably from 0.4% to 38%.

[0043] Figure 8 This is a schematic diagram illustrating another arrangement of gearbox 200. In the embodiment discussed above, the clearing port 252 is located in slot 250, but the embodiment discussed herein can be applied to other arrangements of gearbox 200. Figure 8 An alternative gearbox 200 arrangement is shown. In this embodiment, the slot 250 includes a plurality of slot openings 256 surrounding the periphery of the slot 250. Each slot opening 256 allows oil to flow out of the slot 250 and into a cavity 204 formed between the slot 250 and the housing 206 of the gearbox 200. In this embodiment, a purge port 252 is located in the housing 206, and more specifically, at the bottom of the housing 206, such that gravity can help oil flow to the purge port 252.

[0044] Further aspects of this disclosure are provided by the subject matter of the following clauses.

[0045] A gearbox includes an oil system, a rotor, and a slot. The oil system is configured to supply oil to the gearbox. The rotor is rotatable about a rotational axis in a rotational direction. The rotor has a radial direction and discharges oil radially outward as the rotor rotates. The slot is positioned radially outward of the rotor in the radial direction to collect the oil discharged by the rotor as it rotates. The radial distance from the rotational axis of the rotor to the slot is variable in the rotational direction.

[0046] According to the gearbox described in the preceding clause, the slot includes a cleaning port. The oil system includes (i) a reservoir fluidly connected to the cleaning port and configured to receive oil from the cleaning port, and (ii) at least one oil nozzle fluidly connected to the reservoir and configured to supply oil to the gearbox.

[0047] The gearbox according to any of the foregoing clauses, wherein the slot is eccentrically positioned relative to the rotor.

[0048] According to any of the foregoing clauses, the gearbox, wherein the slot has (i) a maximum distance (Dg) from the axis of rotation to the slot. max (ii) The minimum distance (Dg) from the axis of rotation to the groove min (iii) an eccentricity (ε) ranging from two per thousand to seventy-six percent. The eccentricity (ε) is the ratio of the eccentric distance (e) to the center gap (C). The eccentric distance (e) is given by: e = (Dg) max –Dg min ) / 2, and the center gap (C) is given by the following formula: C=(Dg max +Dg min ) / 2-Rr.

[0049] According to any of the preceding clauses, the gearbox includes a slot center. The slot center is offset from the axis of rotation of the rotor in the radial direction.

[0050] According to any of the foregoing clauses, the gearbox has a rotor having a radius (Rr). The slot has a radius (Rg). The center of the slot is offset by an eccentricity (e) in the radial direction of the rotor, having an eccentricity (ε) from two per thousand to seventy-six percent. The eccentricity (ε) is the ratio of the eccentricity (e) to the difference (Rg – Rr) between the slot radius and the rotor radius.

[0051] According to any of the preceding clauses, the gearbox includes a clearing port. The center of the gearbox is offset by an eccentric angle between 270 and 360 degrees from the axis of rotation of the rotor. The eccentric angle is an angular position relative to a reference position in the direction of rotation of the rotor. The reference position is the center of the clearing port.

[0052] The gearbox according to any of the foregoing clauses further includes a planetary gear train. The planetary gear train includes a sun gear, a plurality of planetary gears, and a ring gear. The sun gear is configured to receive torque and rotate about an axis of rotation. Each of the plurality of planetary gears engages with the sun gear to be rotated by the sun gear. The ring gear engages with each of the plurality of planetary gears.

[0053] The gearbox according to any of the foregoing clauses, wherein the slot is located radially outside the gear ring in the direction of rotation of the rotor.

[0054] The gearbox according to any of the foregoing clauses, wherein the groove is integrally formed with the gear ring.

[0055] According to any of the foregoing clauses, in a gearbox, the ring gear engages with each of the plurality of planetary gears to rotate about the axis of rotation of the sun gear. The ring gear is the rotor, and the axis of rotation of the rotor is the axis of rotation of the sun gear.

[0056] According to any of the foregoing clauses, the gearbox wherein the plurality of planetary gears are rotatable together about the axis of rotation of the sun gear. The plurality of planetary gears are the rotor, and the axis of rotation of the rotor is the axis of rotation of the sun gear.

[0057] The gearbox according to any of the foregoing clauses further includes a carrier. The planetary gears are rotatably connected to the carrier. As the plurality of planetary gears rotate together, the carrier rotates about the axis of rotation of the sun gear.

[0058] According to any of the foregoing clauses, in a gearbox, each planetary gear meshes with the sun gear at a backlash formed between the sun gear and the corresponding planetary gear. The oil system includes at least one oil nozzle configured to inject oil into one of the backlashes formed between the sun gear and the corresponding planetary gear.

[0059] According to any of the foregoing clauses, the gearbox wherein the at least one oil nozzle is located upstream of the tooth gap and injects oil in a direction toward the tooth gap.

[0060] According to any of the foregoing clauses, in a gearbox, each planetary gear meshes with the ring gear at a backlash formed between the ring gear and the corresponding planetary gear. The oil system includes at least one oil nozzle configured to inject oil into one of the backlashes formed between the ring gear and the corresponding planetary gear.

[0061] According to any of the foregoing clauses, the gearbox wherein the at least one oil nozzle is located upstream of the tooth gap and injects oil in a direction toward the tooth gap.

[0062] A gas turbine engine includes a core, an output element, and a gearbox according to any of the preceding clauses. The core includes a compression section, a combustion section, and a turbine section. The gearbox is coupled to the core to transmit torque and power from the core to the output element.

[0063] The gas turbine engine according to the foregoing clause further includes a fan. The fan includes a fan rotor and a plurality of fan blades extending radially outward from the fan rotor. The fan rotor is the output element.

[0064] The gas turbine engine according to any of the foregoing clauses further includes a propeller assembly. The propeller assembly includes a propeller shaft and a plurality of propeller blades extending outwardly from the propeller shaft. The propeller shaft is the output element.

[0065] A gearbox for a gas turbine engine. The gearbox includes a rotor, a housing, and a slot. The rotor is rotatable about a rotational axis in a rotational direction. The rotor has a radial direction and discharges oil radially outward when the rotor rotates. The housing is positioned radially outward of the rotor. The slot is positioned radially outward of the rotor between the housing and the rotor in the radial direction of the rotor. The slot is also positioned to collect oil discharged by the rotor when the rotor rotates. The slot includes a plurality of slot openings around its periphery. Each of the plurality of slot openings allows oil to flow out of the slot and into a cavity formed between the slot and the housing. The rotor is eccentrically positioned relative to at least one of the housing and the slot.

[0066] A method for collecting oil from a rotating component. The method includes supplying oil to a rotor, causing the rotor to rotate about a rotation axis in a rotational direction and discharging the oil radially outward, and collecting the oil discharged from the rotor in a trough. The trough is positioned radially outward of the rotor in the radial direction, and the radial distance from the rotation axis of the rotor to the trough is variable in the rotational direction.

[0067] According to the method described in the foregoing clause, the slot is eccentrically positioned relative to the rotor.

[0068] According to any of the foregoing clauses, the groove has (i) a maximum distance (Dg) from the axis of rotation to the groove. max (ii) The minimum distance (Dg) from the axis of rotation to the groove min (iii) an eccentricity (ε) ranging from two per thousand to seventy-six percent, said eccentricity (ε) being the ratio of the eccentric distance (e) to the center gap (C), wherein said eccentric distance (e) is given by the following formula: e = (Dg max –Dg min ) / 2, and the center gap (C) is given by the following formula: C=(Dg max +Dg min ) / 2-Rr.

[0069] According to any of the foregoing clauses of the method, the slot includes a slot center. The slot center is offset from the axis of rotation of the rotor in the radial direction of the rotor.

[0070] According to any of the foregoing clauses, the rotor has a radius (Rr), the slot has a radius (Rg), and the center of the slot is offset by an eccentric distance (e) in the radial direction of the rotor to have an eccentricity (ε) from two per thousand to seventy-six percent, the eccentricity (ε) being the ratio of the eccentric distance (e) to the difference (Rg–Rr) between the slot radius and the rotor radius.

[0071] According to any of the foregoing descriptions, the slot includes a clearing port. The center of the slot is offset by an eccentric angle between 270 and 360 degrees from the axis of rotation of the rotor. The eccentric angle is an angular position relative to a reference position in the direction of rotation of the rotor. The reference position is the center of the clearing port.

[0072] According to any of the foregoing descriptions of the method, the rotor is part of a planetary gear system. The method further includes rotating a sun gear about a rotation axis to rotate the rotor.

[0073] According to any of the foregoing descriptions, the rotor is connected to the ring gear of the sun gear via a plurality of planetary gears. Each of the plurality of planetary gears engages with the sun gear to be rotated by the sun gear, and the ring gear engages with each of the plurality of planetary gears to rotate about the axis of rotation of the sun gear.

[0074] According to any of the foregoing clauses, the rotor is a plurality of planetary gears that rotate together about the axis of rotation of the sun gear. Each of the plurality of planetary gears engages with the sun gear to be rotated by the sun gear and engages with a ring gear.

[0075] According to any of the foregoing provisions, the groove is integrally formed with the gear ring.

[0076] According to any of the foregoing provisions, each planetary gear meshes with the sun gear at a backlash formed between the sun gear and the corresponding planetary gear. The method further includes injecting oil into at least one backlash formed between the sun gear and the corresponding planetary gear.

[0077] According to any of the foregoing clauses, each planetary gear meshes with the ring gear at a tooth gap formed between the ring gear and the corresponding planetary gear. The method further includes injecting oil into at least one tooth gap formed between the ring gear and the corresponding planetary gear.

[0078] According to any of the foregoing provisions, the oil is injected upstream of the tooth gap.

[0079] While the foregoing description is directed to preferred embodiments, it is worth noting that other variations and modifications will be apparent to those skilled in the art and can be made without departing from the spirit or scope of this disclosure. Furthermore, features described in connection with one embodiment can be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A gearbox for a gas turbine engine, characterized in that, The gearbox includes: A rotor, the rotor being rotatable about a rotation axis in a rotational direction, the rotor having a radial direction and discharging oil radially outward as the rotor rotates; and A groove, positioned radially outward of the rotor in the radial direction, collects oil discharged from the rotor as it rotates. The radial distance from the rotor's axis of rotation to the groove is variable in the rotational direction. The groove includes a groove center, which is offset from the rotation axis of the rotor in the radial direction. The rotor has a radius Rr. Wherein, the groove has a radius Rg, and The center of the slot is offset by an eccentricity e in the radial direction of the rotor, having an eccentricity ε ranging from two per thousand to seventy-six percent, wherein the eccentricity ε is the ratio of the eccentricity e to the difference Rg–Rr between the slot radius and the rotor radius.

2. The gearbox according to claim 1, characterized in that, in, The slot includes a clearing port, and The gearbox further includes an oil system configured to supply oil to the gearbox, the oil system including a reservoir fluidly connected to the purge port and configured to receive oil from the purge port, and at least one oil nozzle fluidly connected to the reservoir and configured to supply oil to the gearbox.

3. The gearbox according to claim 1, characterized in that, in, The slot includes a cleaning port, the cleaning port having a center, and The eccentric angle between the center of the slot and the axis of rotation of the rotor, which is offset by 270 degrees and 360 degrees, is the angular position from the reference position to the reference line formed between the axis of rotation of the rotor and the center of the slot in the direction of rotation of the rotor. The reference position is the center of the cleaning port.

4. The gearbox according to claim 1, characterized in that, The system further includes a revolute gear train, which comprises: Sun gear, the sun gear being configured to receive torque and rotate about a rotation axis; A plurality of planetary gears, each of which engages with the sun gear for rotation by the sun gear; and A gear ring, which engages with each of the plurality of planetary gears.

5. The gearbox according to claim 4, characterized in that, in, The slot is located radially outside the gear ring in the direction of rotation of the rotor.

6. The gearbox according to claim 4, characterized in that, in, The groove is integrally formed with the gear ring.

7. The gearbox according to claim 4, characterized in that, in, The gear ring engages with each of the plurality of planetary gears to rotate about the rotation axis of the sun gear, the gear ring being the rotor, and the rotation axis of the rotor being the rotation axis of the sun gear.

8. The gearbox according to claim 4, characterized in that, in, The plurality of planetary gears are capable of rotating together about the rotation axis of the sun gear, the plurality of planetary gears being the rotor, and the rotation axis of the rotor being the rotation axis of the sun gear.

9. The gearbox according to claim 8, characterized in that, It further includes a bracket on which the planetary gears are rotatably connected, and which rotates about the axis of rotation of the sun gear as the plurality of planetary gears rotate together.

10. The gearbox according to claim 4, characterized in that, in, Each planetary gear meshes with the sun gear at a tooth gap formed between the sun gear and the corresponding planetary gear, and the gearbox further includes an oil system comprising at least one oil nozzle configured to inject oil into one of the tooth gaps formed between the sun gear and the corresponding planetary gear.

11. The gearbox according to claim 10, characterized in that, in, The at least one oil nozzle is located upstream of the tooth gap and injects oil in the direction toward the tooth gap.

12. The gearbox according to claim 4, characterized in that, in, Each planetary gear meshes with the ring gear at a backlash formed between the ring gear and the corresponding planetary gear, and the gearbox further includes an oil system comprising at least one oil nozzle configured to inject oil into one of the backlashes formed between the ring gear and the corresponding planetary gear.

13. The gearbox according to claim 12, characterized in that, in, The at least one oil nozzle is located upstream of the tooth gap and injects oil in the direction toward the tooth gap.

14. A gas turbine engine, characterized in that, include: The core comprises a compression section, a combustion section, and a turbine section; A fan, the fan including a fan rotor and a plurality of fan blades extending radially outward from the fan rotor; as well as The gearbox of claim 1, wherein the gearbox is coupled to the core to transmit torque and power from the core to the fan rotor.

15. A gas turbine engine, characterized in that, include: The core comprises a compression section, a combustion section, and a turbine section; A propeller assembly, the propeller assembly including a propeller shaft and a plurality of propeller blades extending outwardly from the propeller shaft; and The gearbox of claim 1, wherein the gearbox is coupled to the core to transmit torque and power from the core to the propeller shaft.

16. A gearbox for a gas turbine engine, characterized in that, The gearbox includes: A rotor capable of rotating about a rotation axis in a rotational direction, the rotor having a radial direction and discharging oil radially outward when the rotor rotates; A housing, the housing being positioned radially outward of the rotor; and A groove, positioned radially outward of the rotor between the housing and the rotor in the radial direction of the rotor, is configured to collect oil discharged by the rotor as the rotor rotates and includes a plurality of groove openings around the periphery of the groove, each of the plurality of groove openings allowing oil to flow out of the groove and into a cavity formed between the groove and the housing. The rotor is eccentrically positioned relative to at least one of the housing and the slot. The rotor has a radius Rr. Wherein, at least one of the outer casing and the groove has a maximum distance Dg from the axis of rotation to at least one of the outer casing and the groove. max The minimum distance Dg from the axis of rotation to at least one of the housing and the slot min And an eccentricity ε ranging from 0.2% to 76%, wherein the eccentricity ε is the ratio of the eccentric distance e to the center gap C, and The eccentricity e is given by the following formula: e = (Dg) max –Dg min ) / 2, and the center gap C is given by the following formula: C=(Dg) / 2 max +Dg min ) / 2-Rr.

17. A gearbox for a gas turbine engine, characterized in that, The gearbox includes: A rotor, the rotor being rotatable about a rotation axis in a rotational direction, the rotor having a radial direction and discharging oil radially outward as the rotor rotates; and A groove, positioned radially outward of the rotor in the radial direction, collects oil discharged from the rotor as it rotates. The radial distance from the rotor's axis of rotation to the groove is variable in the rotational direction. The rotor has a radius Rr. The groove has a maximum distance Dg from the axis of rotation to the groove. max The minimum distance Dg from the axis of rotation to the groove min And an eccentricity ε ranging from 0.2% to 76%, wherein the eccentricity ε is the ratio of the eccentric distance e to the center gap C, and The eccentricity e is given by the following formula: e = (Dg) max –Dg min ) / 2, and the center gap C is given by the following formula: C=(Dg) / 2 max +Dg min ) / 2-Rr.

18. The gearbox according to claim 17, characterized in that, in, The slot includes a clearing port, and The gearbox further includes an oil system configured to supply oil to the gearbox, the oil system including a reservoir fluidly connected to the purge port and configured to receive oil from the purge port, and at least one oil nozzle fluidly connected to the reservoir and configured to supply oil to the gearbox.

19. The gearbox according to claim 17, characterized in that, in, The slot is eccentrically positioned relative to the rotor.

20. The gearbox according to claim 17, characterized in that, in, The groove includes a groove center that is offset from the rotation axis of the rotor in the radial direction of the rotor.

21. A gearbox for a gas turbine engine, characterized in that, The gearbox includes: A rotor, the rotor being rotatable about a rotation axis in a rotational direction, the rotor having a radial direction and discharging oil radially outward as the rotor rotates; and A groove, positioned radially outward of the rotor in the radial direction, collects oil discharged from the rotor as it rotates. The radial distance from the rotor's axis of rotation to the groove is variable in the rotational direction. The groove includes a groove center, which is offset from the rotation axis of the rotor in the radial direction. The slot includes a cleaning port, the cleaning port having a center, and The eccentric angle between the center of the groove and the rotation axis of the rotor, which is offset by 270 degrees and 360 degrees, is the angular position from the reference position to the reference line formed between the rotation axis of the rotor and the center of the groove in the rotation direction of the rotor. The reference position is the center of the cleaning port.

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