PLANETARY GEAR DEVICE FOR A TURBOMACHINE

Abstract

A planetary gear device for a turbomachine includes a planetary carrier and planetary wheel arranged in an axial direction between two planetary carrier areas connected to a support appliance, with the planetary wheel rotatably mounted on the support appliance. On outer sides facing away from the planetary wheel, the planetary carrier areas include cone surfaces that enclose connection areas with the support appliance, with diameters decreasing with increasing axial distance from the planetary wheel. Cone surfaces of a tensioning appliance radially enclose and are respectively adjusted thereto and act together such that a force that respectively results from an axial tensioning force of the tensioning appliance applied on the cone surfaces of the planetary carrier areas is applied at the connection areas between the support appliance and the planetary carrier areas. The tensioning appliance cone surfaces operatively connect via a coupling element.

Claims

1. A planetary gear device for a turbomachine with a planetary carrier and at least one planetary wheel arranged thereon in a rotatable manner, wherein the planetary wheel is arranged in the axial direction between two planetary carrier areas, with respectively one support appliance being connected with them in a torque-proof manner, with the planetary wheel being mounted on the support appliance in a rotatable manner, characterized in that, at their outer sides that are facing away from the planetary wheel, the planetary carrier areas are respectively embodied with a cone surface that encloses the connection area with the support appliance, their diameters decreasing as the axial distance from the planetary wheel increases and respectively acting together with cone surfaces of a tensioning appliance adjusted to them and radially enclosing the cone surfaces of the planetary carrier areas, namely in such a manner that a force, which results from an axial tensioning force of the tensioning appliance that is respectively applied to the cone surfaces of the planetary carrier areas via a coupling element of the tensioning appliance and presses the connection areas inwards in the radial direction, acts at the connection areas between the support appliance and the planetary carrier areas, wherein the cone surfaces of the tensioning appliance are operatively connected to each other via the coupling element.

2. The planetary gear device according to claim 1, wherein the cone surfaces of the planetary carrier areas and the cone surfaces of the tensioning appliance respectively enclose an angle of between 0.5 to 30 with a rotational axis of the planetary carrier.

3. The planetary gear device according to claim 1, wherein the tensioning appliance is embodied with a disc element and a tensioning element, wherein the tensioning element can be screwed onto the coupling element for creating the tensioning force that acts in the axial direction of the tensioning appliance, and wherein the disc element is embodied with one of the cone surfaces of the tensioning appliance and, in the mounted state of the tensioning appliance, is arranged on the side of the planetary carrier area that is facing away from the planetary wheel between the tensioning element and the planetary carrier area.

4. The planetary gear device according to claim 3, wherein the disc element and the tensioning element are formed in one piece.

5. The planetary gear device according to claim 3, wherein the disc element and the tensioning element are embodied as separate structural components.

6. The planetary gear device according to claim 1, wherein the coupling element is formed in one piece with the tensioning element of the tensioning appliance, wherein one of the cone surfaces of the tensioning appliance is provided in the area of the tensioning element and the tensioning element is arranged on the side of the planetary carrier area that is facing away from the planetary wheel, with the cone surface of which planetary carrier area the cone surface of the tensioning element is in operative connection.

7. The planetary gear device according to claim 1, wherein the support appliance respectively has end stop surfaces, with which the support appliance acts together with the planetary carrier areas in the area of the sides of the planetary carrier areas that face towards the planetary wheel and through which a distance in the axial direction between the planetary carrier areas is defined.

8. The planetary gear device according to claim 1, wherein the tensioning appliance has at least one hydraulic fluid supply channel through which the hydraulic fluid can be conducted in the direction of a bearing appliance of the planetary wheel on the support appliance.

9. The planetary gear device according to claim 8, wherein the support appliance is embodied with at least one recess that substantially extends in the radial direction of the planetary wheel and by means of which hydraulic fluid can be supplied to the bearing appliance.

10. A jet engine with a planetary gear device according to claim 1.

Description

[0030] Further advantages and advantageous embodiments of the subject matter according to the invention follow from the patent claims and from the exemplary embodiments that are described in principle in the following by referring to the drawing, wherein, with a view to clarity, the same reference signs are used in the description of the exemplary embodiments for structural components having the same structure and functionality.

[0031] Herein:

[0032] FIG. 1 shows a simplified sectional view of a jet engine, wherein a fan is operatively connected to a low-pressure turbine via a planetary gear device;

[0033] FIG. 2 shows a strongly simplified partial sectional view of an area of the planetary gear device according to FIG. 1, wherein, in the shown area, the planetary gear device has a planetary wheel, a planetary carrier comprising two planetary carrier areas, as well as a tensioning appliance acting together with the planetary carrier areas; and

[0034] FIG. 3 shows a rendering of a further embodiment of the planetary gear device.

[0035] FIG. 1 shows a turbomachine that is embodied as a jet engine 1 of an aircraft having a planetary gear device 5 that will be described in more detail in the following. The jet engine 1 is a turbomachine that can be advantageously combined with the planetary gear device 5. As will become clear from the following description, the planetary gear device 5 can also be used with differently embodied turbomachines.

[0036] The jet engine 1 has a main rotational axis 2. Further, the jet engine 1 comprises in the axial flow direction A an air intake 3, a fan 4, a planetary gear device 5, a low-pressure compressor 6, a high-pressure compressor 7, a combustion appliance 8, a high-pressure turbine 9, a low-pressure turbine 10 and a discharge nozzle 11. An engine nacelle 12 surrounds the jet engine 1 and delimits the air intake 3.

[0037] The jet engine 1 operates in a conventional manner, wherein air entering the intake 3 is accelerated by the fan 4 to create two air flows. A first air flow flows into the intermediate-pressure compressor 6 and a second air flow is passed through a subsidiary flow channel 13 or bypass channel to provide a drive thrust. The low-pressure compressor 6 compresses the air flow that is supplied to it, before the air is further compressed in the area of the high-pressure compressor 7.

[0038] The compressed air that is discharged from the high-pressure compressor 7 is introduced into the combustion appliance 8, where an intermixing with fuel occurs, and the fuel-air mixture is combusted. The resulting hot combustion products expand and in doing so drive the high-pressure turbine 9 and the low-pressure turbine 10, before they are discharged via the discharge nozzle 11 to provide additional drive thrust. The high-pressure turbine 9 and the low-pressure turbine 10 drive the high-pressure compressor 7 or the low-pressure compressor 6 by means of a high-pressure shaft 14 or a low-pressure shaft 15. The low-pressure shaft 15 that couples the low-pressure turbine 10 with the low-pressure compressor 6 is coupled to the fan 4 via the planetary gear device 5 which represents a reduction gear wherein a drive torque that is applied to the planetary gear device 5 via the low-pressure shaft 15 is increased corresponding to the stationary gear ratio of the planetary gear device 5, and is supplied to a fan shaft 16. If the fan 4 is driven by the low-pressure turbine 10, the rotational speed of the low-pressure shaft 15 is reduced corresponding to the gear ratio of the planetary gear device 5, and the fan shaft 16 as well as the fan 4 are driven with this reduced rotational speed and with a torque that is increased with respect to the torque applied to the low-pressure shaft 15.

[0039] In the shown embodiment of the planetary gear device 5, a sun wheel 18 of the planetary gear device 5 is connected in a torque-proof manner with the low-pressure shaft 15, and a planetary carrier 19 of the planetary gear device 5 is connected in a torque-proof manner with the fan shaft 16. A hollow wheel 20 of the planetary gear device 5 is attached in a manner fixed tot he housing. What is thus present is a planetary gear device 5 that is embodied as an epicyclic planetary gear, in which strong centrifugal forces act on the planetary wheels 21 of the planetary gear device 5 during operation of the jet engine 1.

[0040] FIG. 2 shows an area of the planetary gear device 5 in which an attachment of a planetary wheel 21 to the planetary carrier 19, which in the present case is embodied in one piece, is present. The planetary carrier 19 has two planetary carrier areas 24, 25 that are embodied with plate-shaped areas and that are respectively connected via a press fit 27 to a support appliance 28 that is embodied as a sleeve or bolt in an inner area with respect to a central axis 26 of the planetary wheel 21. In the present case, the support appliance 28 has a support element 29 that is connected via a press fit 27 with the planetary carrier areas 24, 25 and a spacer element 30 that is embodied with end stop surfaces 90, 91 at which the planetary carrier areas 24, 25 abut. With respect to the central axis 26, the spacer element 30 is arranged in the radial direction R outside the support element 29, in particular adjoining the same. A distance in the axial direction A of the jet engine 1 between the planetary carrier areas 24, 25 is defined by means of the spacer element 30. In an alternative embodiment, the support element 29 and the spacer element 30 can be embodied integrally or in one piece with each other.

[0041] Alternatively, there is also the possibility of embodying the planetary carrier with multiple parts.

[0042] In the present case, the planetary wheel 21 is mounted at the spacer element 30 that is embodied as a socket by means of a bearing appliance 34 embodied as a slide bearing. Here, the planetary wheel 21 is arranged in the axial direction between the planetary carrier areas 24 and 25.

[0043] The first planetary carrier area 24 as well as the second planetary carrier area 25 have respectively one cone surface 37 or 38 that encloses a connection area 22, 23 with the support appliance 28 in the circumferential direction in the area of outer sides 39, 40 that are facing away from the longitudinal central plane 36 of the planetary wheel 21. The cone surfaces 37 and 38 of the planetary carrier areas 24 and 25 are respectively embodied as an outer cone and extend beyond the outer sides 39 and 40 of the planetary carrier areas 24 and 25. Here, the diameter of the cone surfaces 37 and 38 respectively steadily decreases in the axial direction A outwards, starting at the outer sides 39 and 40. At that, the cone surfaces 37 and 38 respectively enclose an angle 43 or 44, which preferably lies respectively between 1 and 10, with respect to the axial direction A or a rotational axis of the planetary wheel 21.

[0044] Further provided is a tensioning appliance 46 that is embodied as a tie rod appliance having a coupling element 47. The coupling element 47 additionally acts together with a disc element 49 and a tensioning element 50 on the outer side 40 of the planetary carrier area 25 that is facing away from the planetary wheel 21. In a first axial end area, the bolt-like coupling element 47 is embodied in one piece with an anchor-shaped tensioning element 52 that is embodied with a cone surface 53 that is adjusted to the cone surface 37 of the planetary carrier area 24. The cone surface 53 is embodied as an inner cone and in the mounted state of the tensioning appliance 46 acts together with the outer cone or the cone surface 37 of the first planetary carrier area 24 from radially outside in the radial direction R.

[0045] In the mounted operational state, the inner diameter of the cone surface 53 steadily decreases in the direction of an area that is facing away from the outer side 39, starting from an area that is facing towards the outer surface 39 of the planetary carrier area 24. Further, the cone surface 53 encloses an angle 55 with the axial direction A that is identical to the angle 43 between the cone surface 37 and the axial direction A.

[0046] A projection of a surface 56 in the radial direction R, which corresponds to an overlapping area or an abutment area between the cone surface 37 of the planetary carrier area 24 and the cone surface 53, is provided at least as an abutment surface 58 between the planetary carrier area 24 and the support appliance 29. In this way, a sufficiently high retaining force can be created between the planetary carrier area 24 and the support appliance 29, by means of which a relative rotational movement between the support appliance 29 and the planetary carrier area 24 can be prevented in a reliable manner. In addition, at least the projection of the surface 56 in the axial direction A is also provided as an abutment surface 62 in the axial direction between the planetary carrier area 24 and the support appliance 24, or at its spacer element 30.

[0047] The disc element 49 has an inner bore 57, so that the disc element 49 can be guided over an end area 59 of the coupling element 47. The tensioning element 50 that is embodied as a nut is embodied with an inner thread 61 that is provided for interacting with an outer thread 60 that is provided at the end area 59 of the coupling element 47.

[0048] Further, the disc element 49 is embodied with a cone surface 63 that is formed as an inner cone and that in the mounted operational state of the planetary gear device 5 acts together with the cone surface 38 of the planetary carrier area 25. Here, the diameter of the cone surface 63 steadily decreases in the direction of an area of the cone surface 63 that is facing away from the outer surface 40, starting from an area that is facing towards the outer surface 40 of the planetary carrier area 25. At that, the cone surface 63 of the disc element 49 encloses an angle 66 equal to the angle 44 with the axial direction A of the planetary gear device 5.

[0049] During mounting of the planetary gear device 5, the coupling element 47 is first guided, with its end that comprises the outer thread 60, in the axial direction A through the planetary carrier area 24 and the support appliance 29 until the outer thread 60 protrudes from the planetary carrier area 25 and the cone surfaces 37 and 53 abut each other. Subsequently, the disc element 49 is guided across the end area 59 of the coupling element 47 and finally increasingly pressed against the cone surface 38 of the planetary carrier area 25 with its cone surface 63 via the tensioning element 50 by screwing the tensioning element 50 onto the coupling element 47, while at the same time the cone surface 53 of the coupling element 47 is being pressed to the cone surface 38 of the planetary carrier area 24. Corresponding of the provided tightening torque of the tensioning element 50, a tensile force acting in the direction of the arrow 68 is applied to the group. This axial tensile force results in a radially inwardly directed compressive force, with its direction of action being indicated by arrow 69 in FIG. 2.

[0050] The compressive force results from the operative connections in the area between the cone surfaces 37 and 38 the planetary carrier areas 24 and 25 and the cone surfaces 53 and 61 of the tensioning appliance 46. The compressive force counteracts a centrifugal force that is applied during operation to the planetary wheel 21 in the direction of the arrow 70. The retaining forces that respectively result from the compressive force from the tensioning appliance 46 and the press fit 27 between the support appliance 29 and the planetary carrier areas 24 and 25 are overcome by the centrifugal force only when the loads are introduced in the area of the planetary carrier areas 24 and 25, equalizing and exceeding the pre-stress that is generated through the tensioning appliance 46 in the area of the planetary carrier areas 24 and 25, and then facilitate or allow a relative rotational movement between the support appliance 29 and the planetary carrier areas 24 and 25.

[0051] Further, FIG. 2 shows simplified components of a hydraulic circuit 72 provided for supplying the slide bearings 34 with hydraulic fluid. Here, the coupling element 47 has a hydraulic fluid supply channel 73 that, starting from the second end area 59, extends in the axial direction A in the direction of the longitudinal central plane 36. In the present case, a hydraulic fluid filter 75 is arranged therein. Connecting to the hydraulic fluid supply channel 73 is a further hydraulic fluid supply channel 74 that is arranged in the radial direction R in the area of the longitudinal central plane 36. Via the hydraulic fluid supply channels 73, 74, a space 76 that is delimited by the tensioning appliance 46 and the retaining appliance 28 can be supplied with hydraulic fluid, wherein the space 76 is particularly well sealed against the environment thanks to the interaction of the encasing appliances 24, 25 with the clamp-in appliance 46. Through the recesses 78, 79, in the present case two, that extend in the radial direction R through the retaining appliance 28, hydraulic fluid that is present in the space 76 can be supplied to the slide bearing 34.

[0052] FIG. 3 shows a further embodiment of the planetary gear device 5, in which the tensioning appliance 46 is embodied with an anchor-shaped tensioning element 52 in the area that acts together with the planetary carrier area 24. Since the planetary gear device 5 according to FIG. 3 generally has the structure as it has been described in connection with FIG. 2, only the differences between the planetary gear devices 5 according to FIG. 2 and FIG. 3 are explained in more detail in the following description. Thus, as far as the further structure and further functionalities of the planetary gear device 5 according to FIG. 3 are concerned, it is referred to the above description regarding FIG. 2.

[0053] The cone surface 37 of the planetary carrier area 24 is provided in the area of a disc element 85 that abuts the outer side 39 of the planetary carrier area 24. Here, in the area of its outer side 39, the planetary carrier area 24 is formed with an annular collar 86 at which the disc element 85 abuts at the planetary carrier area 24, and thus has a greater axial width in this area. Thus, the outer side 39 is embodied with an abutment surface 87 extending in the circumferential direction of the planetary carrier area 24, with the disc element 85 abutting thereat with an abutment surface 88 that also extends in the circumferential direction of the disc element 85, and with the disc element 85 being centered thereat in the radial direction at the planetary carrier area 24.

[0054] In the mounted state of the planetary gear device 5, the disc element 85 is pressed by the tensioning appliance 46 in the axial direction A as well as in the radial direction R against the planetary carrier area 24. Via the disc element 85, the tensioning appliance 46 additionally creates the press fit with the support appliance 28 which creates the retaining forces that are necessary for preventing the rotational movements of the support appliance 28 with respect to the planetary carrier area 14, or in the present case with respect to the disc element 85, which shorten the service life of the planetary gear device 5.

[0055] Depending on the respectively present application case, there is also the alternative or additional possibility of providing the cone surface 38 of the planetary carrier area 25 in the area of an additional disc element, as in the planetary carrier area 24 according to FIG. 3 and to the extent as described with respect to FIG. 3.

PARTS LIST

[0056] 1 turbomachine; jet engine [0057] 2 rotational axis [0058] 3 air intake [0059] 4 fan [0060] 5 planetary gear device [0061] 6 low-pressure compressor [0062] 7 high-pressure compressor [0063] 8 combustion appliance [0064] 9 high-pressure turbine [0065] 10 low-pressure turbine [0066] 11 discharge nozzle [0067] 12 engine nacelle [0068] 13 bypass channel [0069] 14 high-pressure shaft [0070] 15 low-pressure shaft [0071] 16 fan shaft [0072] 17 sun wheel [0073] 18 planetary carrier [0074] 19 hollow wheel [0075] 21 planetary wheel [0076] 22, 23 connection area [0077] 24 planetary carrier area [0078] 25 planetary carrier area [0079] 26 central axis of the planetary wheel [0080] 27 press fit [0081] 28 support appliance [0082] 29 support element [0083] 30 spacer element; socket [0084] 34 bearing appliance; slide bearing [0085] 36 longitudinal central plane of the planetary wheel [0086] 37 cone surface of the planetary carrier area 24 [0087] 38 cone surface of the planetary carrier area 25 [0088] 39 outer side of the planetary carrier area 24 [0089] 40 outer side of the planetary carrier area 25 [0090] 43, 44 angle [0091] 46 tensioning appliance [0092] 47 coupling element [0093] 49 disc element [0094] 50 tensioning element; nut [0095] 52 anchor-shaped tensioning element [0096] 53 cone surface of the tensioning element 52 [0097] 55 angle [0098] 56 surface [0099] 57 inner bore of the disc element [0100] 58 abutment surface [0101] 59 end area of the coupling element [0102] 60 outer thread of the clamp-in element [0103] 61 inner thread of the tensioning element [0104] 62 abutment surface [0105] 63 cone surface of the disc element 49 [0106] 66 angle [0107] 68, 69, 70 arrow [0108] 72 hydraulic circuit [0109] 73 hydraulic fluid supply channel [0110] 74 further hydraulic fluid supply channel [0111] 75 hydraulic fluid filter [0112] 76 space [0113] 78, 79 recesses [0114] 85 disc element [0115] 86 annular collar [0116] 87, 88 abutment surface [0117] 90, 91 end stop surface of the support appliance 28 [0118] A axial direction of the turbomachine [0119] R radial direction of the planetary wheel