CN216478818U

CN216478818U - Gear box

Info

Publication number: CN216478818U
Application number: CN202122599341.3U
Authority: CN
Inventors: 尤亦晨; 陈森; 尹晓利; 金丽媛; 李纪峰
Original assignee: Flender Transmission System Co ltd
Current assignee: Flender Transmission System Co ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-05-10
Anticipated expiration: 2031-10-26

Abstract

The utility model relates to a gearbox comprising a housing (10); a spline housing (30); a planet carrier (20) which drives the spline housing (30) to rotate together, wherein the planet carrier (20) is supported in the shell (10) through a bearing (25); a static seal (40) fixed to the housing (10); a first dynamic seal (50) fixed and relatively statically sealed to the carrier (20) and dynamically sealed to the static seal (40) to seal an oil storage space (70) formed by the bearing (25), the carrier (20), the first dynamic seal (50), the static seal (40) and/or the housing (10), the first dynamic seal (50) being located entirely radially outside of the spline housing (30); and a second dynamic seal (60) which is detachably fixed to the carrier (20) independently of the first dynamic seal (50) and abuts the spline housing (30) in the axial direction (Z).

Description

Gear box

Technical Field

The utility model relates to a gear box, in particular to a gear box for a scraper machine under a mine.

Background

The coal mine scraper is a common device in the coal mining industry, and a gear box of the coal mine scraper is mainly composed of a motor component, a transmission component and an output component. The output assembly mainly comprises a planet carrier of the planetary gear mechanism and a spline sleeve which is meshed with the planet carrier and driven by the planet carrier, and the planet carrier is supported in a shell of the gear box through a bearing. The output assembly also includes a stationary seal ring secured to the housing and a moving seal ring secured to the outer end of the planet carrier. During the operation of the gearbox, the spline sleeve and the movable sealing ring rotate around the central axis together with the planet carrier under the driving of the planet carrier, dynamic sealing is formed between the movable sealing ring and the static sealing ring, and lubricating oil used for lubricating the bearing is sealed in an oil storage space formed by the planet carrier, the bearing, the shell and/or the static sealing ring and the movable sealing ring.

However, the dynamic seal ring also axially abuts the spline housing. During operation of the gearbox, sometimes an axial force in the direction of the centre axis is transmitted to the spline housing, for example from the inside outwards towards the dynamic seal ring, which force is transmitted from the spline housing to the dynamic seal ring abutting against it and finally received by a fastening element, for example a screw, for fastening the dynamic seal ring to the planet carrier.

The long-term cyclic action of this axial force can lead to screw failure, for example fracture, the dynamic sealing ring is no longer tightened and the dynamic seal between the dynamic and static sealing rings is broken, thus directly breaking the seal to the oil storage space. Oil leakage occurs at the output end of the gear box.

It is therefore desirable to improve upon existing gearbox designs to address the above-mentioned technical problems.

SUMMERY OF THE UTILITY MODEL

The utility model aims to improve the structure of a gearbox and overcome the problem of oil leakage of the gearbox caused by the reasons.

The application provides a gearbox, including: a housing; a spline housing for outputting rotational motion; a planet carrier engaged with the spline housing to drive the latter together for rotation about an axial direction, the planet carrier being supported within the housing by bearings; a static seal secured to the housing; a first dynamic seal fixed to and relatively statically sealed to the carrier and dynamically sealed to the static seal to seal an oil storage space formed by the bearing, the carrier, the first dynamic seal, the static seal and/or a housing, the first dynamic seal being located entirely radially outward of the spline housing; and a second dynamic seal that is detachably fixed to the carrier independently of the first dynamic seal, and abuts the spline housing in the axial direction.

In one embodiment, the first dynamic seal includes a first annular body configured for dynamic sealing to the static seal and a first flange extending radially inward from the first annular body, the first flange being fixed to the carrier.

In one embodiment, the second dynamic seal includes a second annular body configured for axial abutment against the spline housing and a second flange extending radially outward from the second annular body and fixed to the planet carrier.

In one embodiment, the first flange directly abuts the carrier in the axial direction, a first fastener is fastened to the carrier through a first fastener hole that extends through the first flange, and in the axial direction:

the second flange directly abuts against and fixes the carrier, and a second fastener is fastened to the carrier through a second fastener hole penetrating through the second flange; or

The second flange indirectly fixes the carrier in abutment, and a second fastener is fastened to the carrier through a second fastener hole that passes through the second flange and through a hole or a notch formed on the first flange.

In one embodiment, the first and second flanges are each a unitary annular structure, the first and second flanges at least partially overlapping and abutting in an axial direction, or the first and second flanges do not overlap in an axial direction but abut and are fixed to outer and inner annular surfaces of the planet carrier, respectively, wherein the outer and inner annular surfaces are different portions of the same end surface or are discontinuous end surfaces; or alternatively

The first and second flanges are in the form of a plurality of first annular segments and a plurality of first annular segments, respectively, evenly spaced apart in a circumferential direction around the axial direction, the plurality of first annular segments and the plurality of first annular segments being staggered and directly abutting and fixed to the carrier.

In one embodiment, the static seal includes an axially outward lobe projecting radially inward into the oil storage volume, the first dynamic seal includes an axially inward lobe projecting radially inward into the oil storage volume, and a dynamic seal assembly including a first ring mounted to the axially outward lobe and a second ring mounted to the axially inward lobe effects a dynamic seal between the static seal and the first dynamic seal.

In one embodiment, the first ring member includes an integrally formed first ring body and first lip, and the second ring member includes an integrally formed second ring body and second lip, wherein the first ring member is mounted to the axially outward lobe of the static seal and the second ring member is mounted to the axially inward lobe of the first dynamic seal such that: the first ring radially urges a first seal ring outwardly against an inner surface defining the axially outward lobe, the second ring radially urges a second seal ring outwardly against a second inner surface defining the axially inward lobe, and the first and second lips abut and dynamically seal together in an axial direction.

In one embodiment, the first annular body of the first dynamic seal comprises a groove on an axially inner side for at least partially receiving the second ring member.

In one embodiment, the static seal includes a body portion secured to the housing and an abutment portion axially abutting and sealed to the bearing, the abutment portion being biased radially inwardly from the body portion and extending in an axial direction to the bearing, the abutment portion defining the axially outward lobe.

In one embodiment, the second annular body of the second dynamic seal comprises an axially inward end surface adapted to axially abut the spline housing, the inner end surface abutting the step of the spline housing directly or via an intermediate ring.

In one embodiment, the first annular body of the first dynamic seal comprises a radially inward surface from which the first flange projects inwardly, and the radially inward surface comprises a recess adapted to receive a seal ring.

The gearbox according to the utility model comprises two dynamic seals which are fastened to the planet carrier independently of each other, but both rotate with the planet carrier. The first dynamic seal is fastened to the planet carrier and dynamically sealed to the static seal fixed to the housing, providing a sealing effect on the oil storage space, but not bearing the axial force on the spline housing, so that the sealing of the oil storage space is not affected by the axial force. The second dynamic seal is fastened to the planet carrier while axially abutting against the spline housing, but does not provide any sealing effect to the oil storage space, and is borne by the bolts used for fastening the second dynamic seal to the planet carrier under the condition that the spline housing bears the axial force as described above, so that even if the bolts fail, the sealing of the oil storage space is not endangered. In this way, the problem of oil leakage which may be caused by the axial force borne by the spline housing is thoroughly solved.

Drawings

Further features and advantages of the present invention will be apparent from the description and illustrations that follow, in which specific details of various embodiments according to the utility model are set forth in the accompanying drawings and the description below.

FIG. 1 is a cross-sectional view of an output assembly as part of a gearbox constructed in accordance with the principles of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1;

FIG. 3 is a perspective view of the second dynamic seal of FIG. 1;

fig. 4 is a perspective view of the first dynamic seal of fig. 1.

Detailed Description

Specific embodiments of the present invention and modifications thereof will be described in detail below with reference to the accompanying drawings.

Generally, a gearbox according to the present application includes a housing, typically cast, a drive assembly that may be received within the housing, and an output assembly at least partially received within the housing. Typically, a gearbox input shaft driven by an output shaft of the motor extends through the housing into the housing to drive one or more drive shafts of a drive assembly within the housing for rotation, wherein the input shaft and the drive shafts, and adjacent drive shafts, are connected, most often by way of a gear mesh. For example, the input shaft drives a first transmission shaft extending perpendicularly thereto via a bevel gear pair, and mutually parallel transmission shafts are connected by a spur gear pair. This transmission can change the direction of torque transmission as required, and can obtain the desired reduction ratio by properly setting the gear ratio of the engaged gear pair.

To avoid obscuring the focus of the present application, FIG. 1 illustrates only a portion of the output assembly that is relevant to the structural improvements of the present application, and the gearbox structure that is not relevant to the improvements of the present application has been omitted.

Generally, the output assembly of the gearbox mainly comprises a planetary gear train output structure. The sun gear (not shown) of the planetary gear set output structure is driven to rotate by the drive shaft of the transmission assembly, the ring gear (not shown) of the planetary gear set output structure is fixed to the case or to another housing (labeled as reference numeral 10 in fig. 1, where "case" and "housing" in this application may be the same component or different components attached together) connected to the case, and the carrier 20 of the planetary gear set output structure is driven to rotate by the sun gear. The spline housing 30 is mounted inside the carrier 20, and the spline housing 30 is engaged with an internal spline N (fig. 1) formed on the carrier 20 via an external spline formed on the outer periphery thereof, so that the spline housing 30 rotates about the central axis together with the carrier 20. The spline housing 30 further includes an internal spline formed on an inner peripheral surface thereof so as to output its own rotational motion to a member, such as an output shaft, coupled with the internal spline thereof.

Herein, the direction in which the central axis about which the planet carrier 20 and the spline housing 30 rotate extends is referred to as an axial direction Z, and the direction along the axial direction Z toward the transmission assembly (i.e., the omitted gearbox transmission component in the drawing) is an axially inward direction (i.e., an axially inward direction as indicated by an arrow in the axial direction Z in fig. 1), and is conversely an axially outward direction; a direction perpendicular to the axial direction Z is referred to as a radial direction R, and a direction from the housing 10 toward the spline housing 30 in the radial direction R is a radially inward direction (i.e., a radially inward direction as indicated by an arrow in the radial direction R in fig. 1), whereas a radially outward direction is opposite.

For the carrier member of the gearbox, only that part of the carrier member which carries the spline housing 30 is shown in fig. 1, and not the entire carrier member, the carrier also comprises an integrally formed, axially inwardly extending part for supporting the planet wheels. Herein, the carrier 20 actually refers to the illustrated portion of the carrier, i.e., the outward portion for engaging with the spline housing 30 to output rotational motion.

The carrier 20 is supported in the housing 10 by bearings 25 mounted in the housing 10 so as to rotate about a central axis extending in the axial direction Z. In order to achieve a good and reliable seal against the lubricating oil used to lubricate the bearings 25, the gear box of the present application employs a lubricating oil seal structure that includes one static seal and two dynamic seals.

Specifically, the lubricating oil sealing structure of the present application includes a stationary seal 40 fixed to the housing 10, a first dynamic seal 50 fixed to the carrier 20 and rotating about the center axis together with the carrier, and a second dynamic seal 60 fixable to and detachable from the carrier 20 independently of the first dynamic seal 50, wherein lubricating oil for lubricating the bearing 25 is stored and sealed in an oil storage space 70 formed by the carrier 20, the bearing 25, the stationary seal 40, and the first dynamic seal 50.

Herein, by the second dynamic seal 60 being "fixable to and removable from the carrier independently of the first dynamic seal 50" is meant that neither fixing the second dynamic seal 60 to the carrier 20, nor (in particular) removing the second dynamic seal 60 from the carrier 20, affects, or destroys, the fixing of the first dynamic seal 50 to the carrier 20, so that, if unwanted loosening of the second dynamic seal 60, or even fastener failure, occurs under the axial force from the spline housing 30 mentioned in the background, the fixing of the first dynamic seal 50 to the carrier 20 is not affected.

Regarding the sealing of the oil storage space 70, the bearing 25 is mounted and sealed between the carrier 20 and the case 10 at the axially inner end of the oil storage space 70. Specifically, the bearing inner race of the bearing 25 rotates about the central axis together with the carrier 20, so that the bearing inner race of the bearing 25 forms a relatively stationary mating seal (as denoted by reference numeral S1) with a corresponding portion of the outer peripheral surface of the carrier 20, for example, by press-fitting therebetween. The bearing outer race of bearing 25 is press-fit, and thus relatively statically sealed, to housing 10, represented in fig. 1 by a mating seal S2. The static seal 40 has an inner abutment surface 41 (fig. 2) that axially abuts the bearing 25 (specifically its bearing outer race), thereby forming a static seal S3 between the static seal 40 and the bearing outer race while the static seal 40 is fixed to the housing 10. In some possible embodiments, the static seal 40 may not abut or seal to the bearing outer race, but rather directly seal to the housing 10 by being fastened to the housing 10.

At the axially outer end of the oil storage space 70, on the one hand, the first dynamic seal 50 is fastened to the planet carrier 20 and thus rotates synchronously therewith about the central axis, both of which respectively comprise surfaces which are diametrically opposite each other and which remain relatively stationary. As shown in fig. 2, the seal ring 71 is disposed in a groove formed on a radially inward surface of the first dynamic seal member 50 to seal between the radially opposed surfaces to form a relatively stationary seal S4 (fig. 1). Other techniques that provide a seal between relatively stationary surfaces may be used as will occur to those of skill in the art. On the other hand, during gearbox operation, the seal S5 between first dynamic seal 50 rotating about the central axis and static seal 40 remaining stationary is achieved by dynamic seal assembly 90 described in detail below.

The static seal 40 includes a body portion 410 and an abutment portion 430 that are integrally formed, wherein the body portion 410 is configured for securing to the housing 10, and the abutment portion 430 is configured to seal against a bearing outer race of the bearing 25 when the body portion 410 is secured to the housing 10.

The fixing of the body portion 410 to the housing 10 may be achieved by fasteners (not shown in the drawings) that extend through fastener holes formed in the body portion 410 of the static seal 40 to corresponding holes formed in the housing 10, evenly arranged in a circumferential direction around the axial direction Z, to fix the static seal 40 to the housing 20.

The abutment 430 is first biased inwardly from the body portion 410 in the radial direction R and then extends in the axial direction Z, forming the above-mentioned inner abutment face 41 and forming an axially outward lobe 435 defined by an axially outward end face 431 and a radially inward surface 433 that extends radially inwardly into the oil storage space 70, as shown in fig. 2.

The first dynamic seal 50 includes a first annular body 510 configured to form a dynamic seal S5 with the static seal 40 and the aforementioned opposing static seal S4 with the planet carrier 20, and a first flange 530 projecting radially inward from the first annular body 510 and configured to be secured to the planet carrier 20.

The first annular body 510 includes a radially inward surface 519 (fig. 2), and the first flange 530 projects inwardly from the radially inward surface 519. The radially inward surface 519 includes a portion opposite to the outer peripheral surface of the carrier 20, and a recess for receiving the seal ring 71 is formed on the portion of the radially inward surface 519. In some embodiments, the seal ring 71 may also be received in a recess formed on the outer peripheral surface of the planet carrier 20. In other embodiments, any other sealing structure that would occur to one skilled in the art may be used. First fastener holes 542 (see detail view of fig. 4) extend through the first flange 530 in a circumferential direction about the axial direction Z so that the first fasteners 82 (fig. 1) extend therethrough into corresponding holes formed in the carrier 20.

Further, referring to fig. 2, the first annular body 510 includes, axially inward, an axially inward lobe 515 defined by an axially inward end surface 511 and a radially inward surface 513 extending radially inward into the oil storage space 70. The axially inward lobe 515 of the first dynamic seal 50 and the axially outward lobe 435 of the static seal 40 oppose each other in the axial direction Z and define a gap G therebetween that cooperates with the dynamic seal assembly 90 mentioned above and described in detail below to form a dynamic seal S5.

Dynamic seal assembly 90 includes a first ring member 92, a second ring member 94, a first seal ring 96 and a second seal ring 98, see FIG. 1. Referring in detail to fig. 2, the first ring member 92 includes a first inner surface 922 exposed to the oil storage space 70, a concave curved outer surface 924 facing the axially outward lobe 435 of the static seal 40, and a first outer end surface 926, wherein the first inner surface 922, a portion of the first outer end surface 926, and a portion of the curved outer surface 924 define a first ring body 910, and a portion of the first outer end surface 926 and a portion of the curved outer surface 924 define a first lip 930. With the first ring member 92 mounted to the axially outward lobe 435 of the static seal 40, the first seal ring 96 is compressed between the first ring member 910 of the first ring member 92 and the abutment 430 of the static seal 40 (specifically, between the curved outer surface 924 of the first ring member 92 and the radially inward surface 433 of the abutment 430 of the static seal 40) to be elastically deformed while the first lip 930 protrudes into the gap G. The second ring member 94 includes a second inner surface 942 exposed to the oil storage space 70, a concave curved outer surface 944 facing the axially inward convex corner 515 of the first dynamic seal 50, and a second inner end surface 946, wherein the second inner surface 942, a portion of the second inner end surface 946 and a portion of the curved outer surface 944 define a second ring body 950, and a portion of the second inner end surface 946 and a portion of the curved outer surface 944 define a second lip 970. With the second ring member 94 mounted to the axially inward lobe 515 of the first dynamic seal 50, the second seal ring 98 is compressed between the second ring member 950 of the second ring member 94 and the axially inward lobe 515 of the first dynamic seal 50 (specifically between the curved outer surface 944 of the second ring member 94 and the radially inward surface 513 of the first dynamic seal 50) to be elastically deformed, while the second lip 970 projects into the gap G axially abutting together with the first lip 930.

In this manner, during operation of the gearbox, second ring member 94 rotates with first dynamic seal 50 relative to static seal 40 and first ring member 92, and second lip 970 of second ring member 94 and first lip 930 of first ring member 92 frictionally engage and dynamically seal to each other. Preferably, as shown in FIG. 1, second ring member 94 and first ring member 92 are shaped so as to sealingly abut each other at second lip 970 and first lip 930, but the second inner end surface 946 of second ring member 94 and the first outer end surface 926 of first ring member 92 are progressively separated in a radially inward direction so that friction between the two opposing end surfaces is minimized while the respective lips of second ring member 94 and first ring member 92 provide a dynamic seal.

Optionally, but not necessarily, as shown in fig. 1, the first dynamic seal member 50 is formed with a groove 51 on an axially inward end face, and the second ring member 950 of the second ring member 94 extends into the groove 51.

As described in detail immediately above with reference to the drawings, the dynamic seal between the first dynamic seal 50 and the static seal 40 is achieved by the provision of axially opposed lobe structures and the dynamic seal assembly 90 described above. Any other structure capable of achieving a dynamic seal between the two is contemplated by those skilled in the art and is within the scope of the present application.

The sealing of the oil storage space 70 is described in detail above, and the provision and structure of the second dynamic seal 60 of the lubricating oil seal structure ensures that the first dynamic seal 50, which directly seals the oil storage space 70, is not damaged in its sealing effect by the influence of other parts of the gearbox, in particular, a movable part such as the spline housing 30, will be described below.

Generally, the second dynamic seal 60 is located radially inward of the first dynamic seal 50 in the radial direction R, and the second dynamic seal 60 abuts the spline housing 30 in the axial direction Z in addition to being fixed to the carrier 20. In this way, the second dynamic seal 60 is fixed to the carrier 20 independently of the first dynamic seal 50, and both bears the axial force imparted by the spline housing 30 and does not indirectly transmit the axial force received by the spline housing 30 to the first dynamic seal 50 that seals the oil storage space 70. The first dynamic seal 50 is located entirely radially outwardly of the spline housing 30 and does not engage the external spline teeth of the spline housing 30 in any axial direction, so that axial forces on the spline housing 30 are not directly transmitted to the first dynamic seal 50.

Specifically, the second dynamic seal 60 includes a second annular body 610 that axially abuts the spline housing 30 and a second flange 630 that extends radially outward from the second annular body 610.

The second annular body 610 defines an axially inward abutment surface 612 (fig. 1) facing the step 32 of the splined sleeve 30. In the illustrated embodiment, the axially inward abutment surface 612 abuts the step 32 of the spline housing 30 via an intermediate ring 65. Those skilled in the art will appreciate that intermediate ring 65 is not required.

Second flange 630 includes fastener holes 642 therethrough, and second fasteners 84 extend through fastener holes 642 into corresponding holes formed in planet carrier 20. As shown in fig. 1 and 2, the fastener holes 642 may, but need not, be in the form of counter-bored holes for avoiding the fasteners 84 from protruding through the second flange 630.

In the embodiment of fig. 1, there is an overlap or lap in the axial direction Z between the first flange 530 of the first dynamic seal 50 and the second flange 630 of the second dynamic seal 60, so the second fastener 84 needs to pass through the corresponding position formed on the first flange 530 to be fastened to the carrier 20 after passing through the fastener hole 642 on the second flange 630. Visible in the perspective detail view of the first dynamic seal 50 of fig. 4 are the light hole 544 for the second fastener 84 to pass through and the fastener hole 542 (also in the form of a light hole) for the first fastener 82 to pass through.

It is contemplated by those skilled in the art that the location on first dynamic seal 50 where second fastener 84 passes may take a form other than that of light aperture 544, and instead any shape of indentation recessed from the outer peripheral surface of first flange 530 may be provided at a corresponding location on first flange 530 to accomplish the same purpose.

Also, due to the overlap or overlap of the first flange 530 of the first dynamic seal 50 with the second flange 630 of the second dynamic seal 60 in the axial direction Z, the second flange 630 of the second dynamic seal 60 is formed with a recess 644 (see fig. 3) that at least partially receives the fastener 82 that secures the first dynamic seal 50 to the carrier 20. Recess 644 may be in the form of a blind hole extending from stepped surface 641 of second flange 630 into the interior of second flange 630 without extending through second flange 630 so as to receive a previously installed fastener 82. Optionally, in the illustrated embodiment, recess 644 is in the form of a through hole through second flange 630 of second dynamic seal 60, such that manipulation of fastener 82 via said through hole is also possible, e.g., disassembly or further tightening.

In some possible embodiments, the first flange 530 of the first dynamic seal 50 and the second flange 630 of the second dynamic seal 60 may not overlap in the axial direction, so as to achieve the purpose that the fixing and the dismounting of the second dynamic seal 60 do not affect the fixing and the sealing of the first dynamic seal 50 "completely". For example, the first flange 530 of the first dynamic seal 50 is in the form of a plurality of first annular segments evenly spaced apart in the circumferential direction, each first annular segment providing a fastener hole 542 for the fastener 82; and second flange 630 of second dynamic seal 60 is also in the form of a plurality of second annular segments evenly spaced in the circumferential direction, each second annular segment providing a fastener hole 642 for fastener 84, and the plurality of first annular segments and the plurality of second annular segments being staggered in the axial direction, all directly abutting a respective axially outward facing end surface 21 of carrier 20 (fig. 2). For another example, in the case where the dimensions of the carrier 20 are appropriate, the first flange 530 of the first dynamic seal 50 and the second flange 630 of the second dynamic seal 60 are respectively fastened to an outer ring (ring) portion and an inner ring (ring) portion of the axially outward end face of the carrier 20, and the outer ring (ring) portion and the inner ring (ring) portion may be different annular portions of the same axially outward end face 21 in the radial direction R or may be provided by different axially outward end faces arranged in a stepped manner. In general, any structure that performs the same function is intended to be within the scope of the present application.

In the exemplary structure described above with reference to the drawings, the gearbox includes first and second dynamic seals, respectively, that are secured to the planet carrier independently of each other, but both rotate with the planet carrier. The first dynamic sealing piece is fastened to the planet carrier and dynamically sealed to the static sealing piece fixed to the shell, the sealing effect is provided for the oil storage space, but the axial force on the spline housing is not born, so that the sealing effect of the oil storage space is not influenced by the axial force. The second dynamic seal is fastened to the planet carrier while axially abutting against the spline housing, but does not provide any sealing effect to the oil storage space, and is borne by the bolts used for fastening the second dynamic seal to the planet carrier under the condition that the spline housing bears the axial force as described above, so that even if the bolts fail, the sealing of the oil storage space is not endangered. In this way, the problem of oil leakage which may be caused by the axial force borne by the spline housing is thoroughly solved.

Specific embodiments according to the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above specific structures, and encompasses various modifications and equivalent features. Various changes may be made by those skilled in the art without departing from the scope of the utility model.

Claims

1. A gearbox, comprising:

a housing (10);

a spline housing (30) for outputting a rotational motion;

a planet carrier (20), said planet carrier (20) being engaged with said splined hub (30) to drive the latter together in rotation about an axial direction (Z), said planet carrier (20) being supported in said housing (10) by means of bearings (25);

a static seal (40) fixed to the housing (10);

a first dynamic seal (50) fixed and relatively statically sealed to the planet carrier (20) and dynamically sealed to the static seal (40) to seal an oil storage space (70) formed by the bearing (25), the planet carrier (20), the first dynamic seal (50), the static seal (40) and/or a housing (10), the first dynamic seal (50) being located entirely radially outside of the spline housing (30); and

a second dynamic seal (60) detachably fixed to the carrier (20) independently of the first dynamic seal (50) and abutting the spline housing (30) in an axial direction (Z).

2. The gearbox of claim 1, wherein the first dynamic seal (50) includes a first annular body (510) configured for dynamic sealing to the static seal (40) and a first flange (530) extending radially inward from the first annular body (510), the first flange (530) being fixed to the planet carrier (20).

3. The gearbox according to claim 2, characterized in that the second dynamic seal (60) comprises a second annular body (610) configured for axial abutment against the spline housing (30) and a second flange (630) extending radially outwardly from the second annular body (610) and fixed to the planet carrier (20).

4. Gearbox according to claim 3, characterised in that the first flange (530) directly abuts the planet carrier (20) in the axial direction (Z), that a first fastening (82) is fastened to the planet carrier (20) through a first fastening hole (542) through the first flange (530), and that in the axial direction (Z):

the second flange (630) directly abuts and fixes the carrier (20), and a second fastener (84) is fastened to the carrier (20) through a second fastener hole (642) that penetrates through the second flange (630); or

The second flange (630) indirectly fixes the carrier (20) against earth, and second fasteners (84) are fastened to the carrier (20) through second fastener holes (642) that extend through the second flange (630) and through holes (544) or notches formed on the first flange (530).

5. A gearbox according to claim 3,

-the first flange (530) and the second flange (630) are respectively of unitary annular structure, the first flange (530) and the second flange (630) at least partially overlapping and abutting in the axial direction (Z), or the first flange (530) and the second flange (630) do not overlap in the axial direction (Z) but abut and are fixed to an outer annular surface and an inner annular surface, respectively, of the planet carrier (20), wherein the outer annular surface and the inner annular surface are different portions of the same end surface or are discontinuous end surfaces; or

The first flange (530) and the second flange (630) are in the form of a plurality of first annular segments and a plurality of first annular segments, respectively, evenly spaced in a circumferential direction around an axial direction (Z), which are staggered and directly abut and are fixed to the planet carrier (20).

6. Gearbox according to any of claims 1-5, characterized in that the static seal (40) comprises an axially outward lobe (435) projecting radially inwards into the oil storage volume (70), and the first dynamic seal (50) comprises an axially inward lobe (515) projecting radially inwards into the oil storage volume (70), and a dynamic seal assembly (90) comprising a first ring (92) mounted to the axially outward lobe (435) and a second ring (94) mounted to the axially inward lobe (515) effects a dynamic seal between the static seal (40) and the first dynamic seal (50).

7. The gearbox of claim 6, wherein the first ring member (92) includes an integrally formed first ring body (910) and first lip (930), and the second ring member (94) includes an integrally formed second ring body (950) and second lip (970), wherein the first ring member (92) is mounted to an axially outward lobe (435) of the static seal (40) and the second ring member (94) is mounted to an axially inward lobe (515) of the first dynamic seal (50) such that: the first ring body (910) pushes the first seal ring (96) radially outwards against an inner surface defining the axially outward lobe (435), the second ring body (950) pushes the second seal ring (98) radially outwards against a second inner surface defining the axially inward lobe (515), the first lip (930) and the second lip (970) abut each other in the axial direction (Z) and are dynamically sealed together.

8. Gearbox according to claim 7, characterised in that the first annular body (510) of the first dynamic seal (50) comprises a groove (51) axially inside for at least partially receiving the second ring member (94).

9. The gearbox of claim 6, wherein the static seal (40) includes a body portion (410) secured to the housing (10) and an abutment portion (430) axially abutting and sealed to the bearing (25), the abutment portion (430) being offset radially inwardly from the body portion (410) and extending in an axial direction to the bearing (25), the abutment portion (430) defining the axially outward lobe (435).

10. Gearbox according to any of claims 1 to 5, characterized in that the second annular body (610) of the second dynamic seal (60) comprises an axially inward end face (612) adapted to axially abut the spline housing (30), said inner end face abutting the step (32) of the spline housing (30) directly or via an intermediate ring (65).

11. The gearbox of claim 10, wherein the first annular body (510) of the first dynamic seal (50) includes a radially inward surface (519), the first flange (530) projects inwardly from the radially inward surface (519), and the radially inward surface (519) includes a recess adapted to receive a seal ring (71).