A closed planetary structure hoist gear box for offshore platforms

Abstract

This application discloses a closed planetary structure lifting gearbox for offshore platforms, relating to the field of lifting gearboxes. The closed planetary structure lifting gearbox includes a housing assembly with an input shaft at one end and an output shaft at the other. A transmission assembly includes a first-stage planetary gear system, a second-stage planetary gear system, a third-stage planetary gear system, and a fourth-stage planetary gear system. Power is split through the third-stage planetary gear system, with power transmitted to the third-stage planetary carrier and the third-stage internal gear ring. Part of the power is directly transmitted to the third-stage planetary carrier, and the other part is transmitted through the third-stage internal gear ring to the fourth-stage planetary gear system. The fourth-stage internal gear ring then transmits the power back to the third-stage planetary carrier, and finally, the two power components merge on the third-stage planetary carrier.

Description

Technical Field

[0001] This application relates to the field of lifting gearbox technology, and in particular to a closed planetary structure lifting gearbox for marine platforms. Background Technology

[0002] As a key infrastructure in energy development, scientific research, and marine transportation, offshore platforms are increasingly widely used in oil and gas exploration, wind power generation, and marine scientific research. Their operational stability and lifting efficiency are important indicators for evaluating the quality of offshore lifting platforms.

[0003] The lifting system of an offshore platform directly affects the platform's operational efficiency and safety. The lifting gearbox is an important component of the lifting system and is required to have characteristics such as high load-bearing capacity, high reliability, and stable operation.

[0004] Currently, most jack-up offshore platform lifting gearboxes employ a hybrid transmission structure combining parallel stages and planetary stages, as well as a multi-stage planetary structure. The multi-stage planetary structure is generally a four-stage NGW (Next Generation Wheel) configuration, which typically suffers from a long transmission chain from the first to the fourth stage, resulting in a long power transmission path and relatively low gearbox efficiency. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a closed planetary structure lifting gearbox for marine platforms, which is a self-elevating closed planetary structure lifting gearbox for marine platforms with a compact structure, short power transmission path, and high gearbox efficiency.

[0006] To achieve the above objectives, this application provides a closed planetary structure lifting gearbox for offshore platforms, comprising:

[0007] A housing assembly, wherein one end of the housing assembly is provided with an input shaft and the other end is provided with an output shaft;

[0008] The transmission assembly includes an NGW planetary transmission assembly, a three-stage planetary gear system, and a four-stage planetary gear system;

[0009] The input shaft transmits power to the three-stage planetary gear system through the NGW planetary transmission assembly. Part of the power is directly transmitted to the output shaft through the planet carrier in the three-stage planetary gear system, and the other part of the power is transmitted to the planet carrier through the internal gear ring of the three-stage planetary gear system and the four-stage planetary gear system, and then to the output shaft.

[0010] Preferably, the enclosure assembly includes a front enclosure, a middle enclosure, and a mounting cylinder, and the enclosure assembly is a sealed enclosure.

[0011] Preferably, the input shaft is rotatably mounted on the front housing, and the output shaft is rotatably mounted inside the mounting cylinder.

[0012] Preferably, a vent cap and an oil plug are installed on the middle housing.

[0013] Preferably, the NGW planetary transmission assembly includes a first-stage planetary gear system, which includes a first-stage sun gear, first-stage planet gears, a first-stage internal gear ring, and a first-stage planet carrier. The input shaft is fixedly connected to the first-stage sun gear, and the first-stage internal gear ring is fixed to the housing assembly.

[0014] Preferably, the NGW planetary transmission assembly further includes a secondary planetary gear system, which includes a secondary sun gear, secondary planet gears, a secondary internal gear ring, and a secondary planet carrier. The secondary sun gear is fixedly connected to the primary planet carrier, and the secondary internal gear ring is fixed to the housing assembly.

[0015] Preferably, the three-stage planetary gear system includes a three-stage sun gear, a three-stage planet gear, a three-stage internal gear ring, and a three-stage planet carrier. The three-stage sun gear is fixedly connected to the two-stage planet carrier, and the three-stage planet carrier is fixedly connected to the output shaft.

[0016] Preferably, the four-stage planetary gear system includes a fourth-stage sun gear, a fourth-stage planet gear, a fourth-stage internal gear ring, and a fourth-stage planet carrier. The fourth-stage sun gear meshes with the third-stage internal gear ring, the fourth-stage planet carrier is fixed to the housing assembly, and the fourth-stage internal gear ring meshes with the third-stage planet carrier.

[0017] Preferably, a connecting shaft is coaxially fixed on the third-stage sun gear, and the fourth-stage sun gear is fitted onto the connecting shaft and positioned between the third-stage and fourth-stage sun gears.

[0018] Preferably, the housing assembly further includes a primary mounting base, a secondary mounting base, and a quaternary mounting base. The primary mounting base, the secondary mounting base, and the quaternary mounting base are detachably mounted to the housing assembly. The primary mounting base is connected to the primary internal gear ring, the secondary mounting base is connected to the secondary internal gear ring, and the quaternary mounting base is connected to the quaternary planetary gear.

[0019] Compared to the aforementioned background technology, the marine platform enclosed planetary structure lifting gearbox provided in this application features a power split in the input power of the device through a three-stage planetary gear system. Part of the power is directly output through the third-stage planetary carrier, while the other part is transmitted to the fourth-stage planetary gear system through the internal gear ring in the third-stage planetary gear system via splines. The internal gear ring in the fourth-stage planetary gear system then amplifies the power through splines and transmits it back to the third-stage planetary carrier. Finally, the two parts of power merge on the third-stage planetary carrier, shortening the power transmission path and improving the gearbox efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a front sectional view of a closed planetary structure lifting gearbox for an offshore platform.

[0022] Figure 2 This is a front sectional view of the housing assembly of a closed planetary structure lifting gearbox for an offshore platform.

[0023] Figure 3 This is a front sectional view of the transmission assembly of a closed planetary structure lifting gearbox for an offshore platform.

[0024] The components include: 1. Housing assembly; 2. First-stage planetary gear system; 3. Second-stage planetary gear system; 4. Third-stage planetary gear system; 5. Fourth-stage planetary gear system; 101. Front housing; 102. Middle housing; 103. Mounting sleeve; 104. Vent cap; 105. Oil plug; 106. First-stage mounting base; 107. Second-stage mounting base; 108. Fourth-stage mounting base; 201. First-stage sun gear; 202. First-stage planetary gears; 203. First-stage internal gear ring. 204. First-stage planetary carrier; 301. Second-stage sun gear; 302. Second-stage planetary gear; 303. Second-stage internal gear ring; 304. Second-stage planetary carrier; 401. Third-stage sun gear; 402. Third-stage planetary gear; 403. Third-stage internal gear ring; 404. Third-stage planetary carrier; 405. Connecting shaft; 501. Fourth-stage sun gear; 502. Fourth-stage planetary gear; 503. Fourth-stage internal gear ring; 504. Fourth-stage planetary carrier; 6. Input shaft; 7. Output shaft. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] It should be noted that the directional terms such as "upper end," "lower end," "left side," and "right side" used below are defined based on the accompanying drawings in the instruction manual.

[0028] Please refer to Figures 1 to 3 The enclosed planetary structure lifting gearbox for marine platforms provided in this application mainly includes a housing assembly 1 and a transmission assembly.

[0029] One end of the housing assembly 1 is provided with an input shaft 6, and the other end is provided with an output shaft 7;

[0030] The transmission components include NGW planetary transmission components, a three-stage planetary gear system 4, and a four-stage planetary gear system 5;

[0031] The input shaft 6 transmits power to the three-stage planetary gear system 4 through the NGW planetary transmission assembly. Part of the power is directly transmitted to the output shaft 7 through the planet carrier in the three-stage planetary gear system 4, and the other part of the power is transmitted to the planet carrier through the internal gear ring of the three-stage planetary gear system 4 and the four-stage planetary gear system 5, and then to the output shaft 7.

[0032] The housing assembly 1 is entirely sealed, with an input shaft 6 mounted at one end. The input shaft 6 is connected to a power source, optionally a motor. The connection method is that the input shaft 6 and the motor's output shaft 7 are connected via a spline. A rolling bearing is installed between the input shaft 6 and the housing assembly 1 to reduce rotational friction during connection. To ensure the sealing effect of the input shaft 6, an end cap is also installed on the housing assembly 1 to enhance the sealing effect.

[0033] The other end of the housing assembly 1 is connected to the output shaft 7. The output shaft 7 is connected to the transmission assembly via a spline. The spline connection uses tooth tip centering. The output shaft 7 is a climbing gear shaft. The output shaft 7 is connected to the housing assembly 1 via multiple sets of rolling bearings. The purpose of this is to reduce the rotational friction of the output shaft 7. At the same time, the multiple sets of rolling bearings can ensure the stability of the output of the output shaft 7, reduce radial runout, reduce the wear of the output shaft 7, and increase the service life of the output shaft 7.

[0034] The mounting cylinder 103 and the bearing seat are bolted and interference-fitted to the frame of the lifting system, so that the entire gearbox is fixed on the self-elevating marine platform.

[0035] The transmission components include NGW planetary transmission components, a three-stage planetary gear train 4, and a four-stage planetary gear train 5. The three-stage planetary gear 402 series components and the four-stage planetary gear 502 series components form a closed planetary gear train.

[0036] The input shaft 6 transmits power to the three-stage planetary gear system 4 through the NGW planetary transmission assembly. The NGW planetary transmission assembly is a planetary transmission system with the sun gear as input, the internal gear ring as fixed, and the planet carrier as output.

[0037] The power transmitted through the input shaft 6 is delivered to the sun gear of the three-stage planetary gear system via the NGW planetary transmission assembly. The planet carrier of the three-stage planetary gear system and the output shaft 7 are connected by a spline to achieve power transmission. The spline connection adopts tooth tip centering.

[0038] Meanwhile, the internal gear ring in the third planetary gear system is connected to the fourth planetary gear system 5. The internal gear ring in the third planetary gear system drives the sun gear in the fourth planetary gear system 5 to rotate. The planet gears in the fourth planetary gear system 5 are fixed. The internal gear ring in the fourth planetary gear system 5 meshes with the planet carrier in the third planetary gear system.

[0039] In this process, the planetary gears in the fourth-stage planetary gear system 5 are fixed, and through a specific gear ratio, the rotational speed of the planet carrier of the third-stage planetary gear system 4 driven by the internal gear ring of the fourth-stage planetary gear system 5 is kept consistent with the rotational speed directly output by the planet carrier of the third-stage planetary gear system 4.

[0040] Through the above connection method, part of the power of the input shaft 6 is directly transmitted to the output shaft 7 through the planet carrier in the three-stage planetary gear system 4, and the other part of the power is transmitted to the planet carrier through the internal gear ring of the three-stage planetary gear system 4 and the four-stage planetary gear system 5, and then transmitted to the output shaft 7.

[0041] In this process, the power directly output by the third-stage planetary gear system 4 accounts for a relatively small proportion, while the power output through the fourth-stage planetary gear system 5 is relatively large. The power output through the fourth-stage planetary gear system 5 is increased by increasing the torque.

[0042] The input power of this invention is split through a three-stage planetary gear system 4. One part of the power is directly output through the three-stage planetary carrier 404, and the other part is transmitted through the internal gear ring in the three-stage planetary gear system 4 to the four-stage planetary gear system 5 via splines. The internal gear ring in the four-stage planetary gear system 5 then amplifies the power through splines and transmits it back to the three-stage planetary carrier 404. Finally, the two parts of power merge on the three-stage planetary carrier 404, shortening the power transmission path and improving the gearbox efficiency.

[0043] Based on any of the above embodiments, the housing assembly 1 includes a front housing 101, a middle housing 102 and a mounting cylinder 103, and the housing assembly 1 is a sealed housing.

[0044] The front housing 101, the middle housing 102, and the mounting cylinder 103 are fixed with bolts during installation. The connection and sealing of the front housing 101, the middle housing 102, and the mounting cylinder 103 are improved by applying adhesive or adding gaskets at the joint.

[0045] The housing assembly 1 is a split type. The split state of the housing is convenient for processing, which can effectively reduce the production cost of the housing assembly 1, and also facilitate the installation and maintenance of the internal transmission components of the housing assembly 1.

[0046] Based on any of the above embodiments, the input shaft 6 is rotatably mounted on the front housing 101, and the output shaft 7 is rotatably mounted inside the mounting cylinder 103.

[0047] The specific installation positions of input shaft 6 and output shaft 7 are limited, which can effectively improve installation efficiency during assembly.

[0048] Specifically, the left end of the climbing gear shaft is splined to the right end face of the third-stage planetary carrier 404, and a rolling bearing is fitted in the middle of the climbing gear shaft and connected to the mounting sleeve 103. A bearing housing is provided on the right side of the climbing gear shaft, and the bearing housing is connected by a rolling bearing. An end cover is provided on the bearing housing, and the end cover is fixed to the bearing housing by bolts to achieve the sealing function of the lubricating grease inside the bearing housing.

[0049] Based on any of the above embodiments, a vent cap 104 and an oil plug 105 are installed on the middle housing 102.

[0050] The vent cap 104 and oil plug 105 installed on the middle housing 102 facilitate the filling and replacement of the lubricating oil inside the housing assembly 1. The middle housing 102 is located in the area with the largest diameter of the housing assembly 1, and the vent cap 104 and oil plug 105 installed at this position facilitate the replacement of the lubricating oil.

[0051] Based on any of the above embodiments, the NGW planetary transmission assembly includes a first-stage planetary gear system 2, which includes a first-stage sun gear 201, a first-stage planetary gear 202, a first-stage internal gear ring 203, and a first-stage planet carrier 204. The input shaft 6 is fixedly connected to the first-stage sun gear, and the first-stage internal gear ring 203 is fixed on the housing assembly 1.

[0052] The first-stage planetary gear system is an NGW planetary gear system. The first-stage sun gear 201 adopts a floating structure, which is beneficial for load distribution in planetary transmission. The first-stage planetary gear 202 is connected to the first-stage planetary carrier 204 through the first-stage planetary shaft. The first-stage planetary shaft is connected to the first-stage planetary gear 202 through roller bearings.

[0053] The primary planetary shaft, rolling bearing, and primary planetary carrier 204 are assembled into a whole by positioning them with elastic retaining rings.

[0054] The first-stage sun gear 201, the first-stage internal gear ring 203, and the first-stage planet gear 202 mesh with each other to form the first-stage planet gear 202 system.

[0055] The first-stage planetary gear system 2 is a traditional planetary gear transmission system with stable structure and high transmission efficiency. The first-stage external gear ring is fixed, realizing the input of power from the first-stage sun gear 201 and the output of power from the first-stage planet carrier 204.

[0056] Based on any of the above embodiments, the NGW planetary transmission assembly also includes a secondary planetary gear system 3, which includes a secondary sun gear 301, a secondary planet gear 302, a secondary internal gear ring 303, and a secondary planet carrier 304. The secondary sun gear 301 is fixedly connected to the primary planet carrier 204, and the secondary internal gear ring 303 is fixed on the housing assembly 1.

[0057] The second-stage planetary gear 302 system is an NGW planetary gear system. The second-stage sun gear 301 is splined to the first-stage planetary carrier 204 and adopts a floating structure, which is beneficial for load distribution in planetary transmission.

[0058] The secondary planetary gear 302 is connected to the secondary planetary carrier 304 via the secondary planetary shaft, and the secondary planetary shaft is connected to the secondary planetary gear 302 via roller bearings.

[0059] The secondary planetary gear 302, the secondary planetary shaft, the rolling bearing, and the secondary planetary carrier 304 are assembled into a whole by positioning with elastic retaining rings.

[0060] The secondary sun gear 301, the secondary internal gear ring 303, and the secondary planet gear 302 mesh with each other to form the secondary planet gear 302 system.

[0061] The second-stage planetary gear system 3 is a traditional planetary gear transmission system with stable structure and high transmission efficiency. The second-stage external gear ring is fixed, realizing the input of power from the second-stage sun gear 301 and the output of power from the second-stage planet carrier 304.

[0062] Based on any of the above embodiments, the three-stage planetary gear system 4 includes a three-stage sun gear 401, a three-stage planet gear 402, a three-stage internal gear ring 403, and a three-stage planet carrier 404. The three-stage sun gear 401 is fixedly connected to the two-stage planet carrier 304, and the three-stage planet carrier 404 is fixedly connected to the output shaft 7.

[0063] The 402 series of third-stage planetary gears is a closed planetary gear system.

[0064] The third-stage sun gear 401 is splinedly connected to the second-stage planetary carrier 304. A third-stage planetary shaft is mounted on the third-stage planetary gear 402. The third-stage planetary shaft and the third-stage planetary carrier 404 are fixedly assembled with bolts. Rolling bearings are mounted on the third-stage planetary shaft via steps. The third-stage planetary gear 402 and the rolling bearings are positioned and assembled together using elastic retaining rings. The third-stage sun gear 401, the third-stage internal gear ring 403, and the third-stage planetary gear 402 mesh with each other.

[0065] In the three-stage planetary gear system 4, both the third-stage internal gear ring 403 and the third-stage planet carrier 404 are in a state of free rotation.

[0066] Based on any of the above embodiments, the four-stage planetary gear system 5 includes a four-stage sun gear 501, a four-stage planet gear 502, a four-stage internal gear ring 503, and a four-stage planet carrier 504. The four-stage sun gear 501 meshes with the three-stage internal gear ring 403 for transmission. The four-stage planet carrier 504 is fixed to the housing assembly 1, and the four-stage internal gear ring 503 meshes with the three-stage planet carrier 404.

[0067] The third-stage internal gear ring 403 is splined to the fourth-stage sun gear 501 and is fixed together by the two end retaining rings on the spline.

[0068] The fourth-stage planetary shaft and the fourth-stage planetary carrier 504 are fixedly assembled by interference fit. The fourth-stage planetary carrier 504 is fixed to the middle housing 102 by bolts. The rolling bearing is assembled on the fourth-stage planetary shaft through the step of the fourth-stage planetary shaft. The fourth-stage planetary gear 502 and the rolling bearing are positioned and assembled by elastic retaining rings.

[0069] The fourth-stage sun gear 501, the fourth-stage internal gear ring 503, and the fourth-stage planet gear 502 mesh with each other.

[0070] The fourth-stage internal gear ring 503 is splined to the third-stage planetary carrier 404 and is fixed together by the two end retaining rings on the spline.

[0071] In the fourth-stage planetary gear system 5, the planetary gears are fixed. The rotation of the fourth-stage sun gear 501 drives the rotation of the fourth-stage internal gear ring 503 at a fixed speed through a fixed gear ratio. The combined drive of the fourth-stage internal gear ring 503 and the third-stage planetary carrier 404 is at a fixed speed. Therefore, part of the power source of the third-stage planetary carrier 404 always maintains the same speed. By driving the third-stage planetary carrier 404 to rotate at a fixed speed through two power sources, the variable speed lock of the third-stage planetary carrier 404 is avoided.

[0072] Based on any of the above embodiments, a connecting shaft 405 is coaxially fixed on the third-stage sun gear 401, and a fourth-stage sun gear 501 is fitted on the connecting shaft 405 and placed between the third-stage sun gear 401 and the fourth-stage sun gear 501.

[0073] Since the third-stage planetary carrier 404 is connected to the output shaft 7, the fourth-stage planetary gear system 5 is installed between the third-stage planetary system and the second-stage planetary gear system 3.

[0074] Therefore, a connecting shaft 405 is coaxially fixedly mounted on the third-stage sun gear 401, and an inner hole is provided on the fourth-stage sun gear 501. The connecting shaft 405 on the third-stage sun gear 401 passes through the inner hole of the fourth-stage sun gear 501. One end of the connecting shaft 405 is fixedly connected to the second-stage planetary carrier 304, and the other end is fixedly connected to the third-stage sun gear 401. The right end face of the third-stage sun gear 401 contacts the left end face of the climbing gear shaft for axial positioning.

[0075] The positions of the third-stage planetary gear system 4 and the fourth-stage planetary gear system 5 are interchanged through the inner hole of the connecting shaft 405 and the fourth-stage sun gear 501 to satisfy the installation relationship between the third-stage planetary gear system 4 and the fourth-stage planetary gear system 5.

[0076] Based on any of the above embodiments, the housing assembly 1 also includes a primary mounting base 106, a secondary mounting base 107, and a quaternary mounting base 108. The primary mounting base 106, the secondary mounting base 107, and the quaternary mounting base 108 are detachably mounted to the housing assembly 1. The primary mounting base 106 is connected to the primary internal gear ring 203, the secondary mounting base 107 is connected to the secondary internal gear ring 303, and the quaternary mounting base 108 is connected to the quaternary planetary gear 502.

[0077] The primary internal gear ring 203 is fixed to the primary mounting base 106 of the front housing 101 by bolts.

[0078] The secondary internal gear ring 303 is fixed to the secondary mounting base 107 by bolts.

[0079] The fourth-stage planetary gear 502 is fixedly mounted on the fourth-stage mounting base 108 via the fourth-stage planetary shaft.

[0080] The first-stage mounting base 106, the second-stage mounting base 107, and the fourth-stage mounting base 108 can all be detachably installed on the housing assembly 1. While facilitating installation, this improves the stability of the installation of the first-stage internal gear ring 203, the second-stage internal gear ring 303, and the fourth-stage planetary gear 502, thereby achieving the stability and durability of the device structure.

[0081] The specific working process of this invention:

[0082] During operation, power is input through input shaft 6, which is connected to the first-stage sun gear 201 via a spline and transmits power to the first-stage sun gear 201. The first-stage planetary gear 202, through meshing with the first-stage sun gear 201 and the first-stage internal gear ring 203, transmits power from the first-stage NGW planetary gear train from the first-stage sun gear 201 to the first-stage planetary carrier 204.

[0083] The first-stage planetary carrier 204 and the second-stage sun gear 301 are connected by a spline to transmit power. The second-stage planetary gear 302 meshes with the second-stage sun gear 301 and the second-stage internal gear ring 303, and the power is transmitted from the second-stage sun gear 301 to the second-stage planetary carrier 304 through the second-stage NGW planetary gear system.

[0084] The second-stage planetary carrier 304 and the third-stage sun gear 401 are connected by a spline to transmit power. The third-stage planetary gear 402 meshes with the third-stage sun gear 401 and the third-stage internal gear ring 403. The fourth-stage planetary shaft is fixed to the third-stage planetary carrier 404 by bolts. A portion of the power is transmitted to the third-stage planetary carrier 404 through the third-stage planetary shaft, and another portion of the power is transmitted to the third-stage internal gear ring 403, thereby achieving power splitting.

[0085] The third-stage internal gear ring 403 and the fourth-stage sun gear 501 are connected by a spline to transmit power. The fourth-stage planetary gear 502, through meshing with the fourth-stage sun gear 501 and the fourth-stage internal gear ring 503, transmits power to the fourth-stage internal gear ring 503. The fourth-stage internal gear ring 503 and the third-stage planetary carrier 404 are connected by a spline to transmit power, thus completing the power confluence and meeting the design requirements of a closed planetary structure.

[0086] The third-stage planetary carrier 404 is connected to the climbing gear shaft via a spline to transmit power, which is ultimately output through the output pinion on the climbing gear shaft.

[0087] The right end of the input shaft 6 is splinedly connected to the primary sun gear 201. A rolling bearing is fitted between the input shaft 6 and the front housing 101.

[0088] The first-stage planetary gear 202, the first-stage planetary shaft, the rolling bearing, and the first-stage planetary carrier 204 are assembled together as a whole by positioning with elastic retaining rings. The first-stage internal gear ring 203 is fixed to the front housing 101 and the first-stage mounting base 106 by bolts. The first-stage sun gear 201, the first-stage internal gear ring 203, and the first-stage planetary gear 202 mesh with each other to form the first-stage planetary gear 202 system assembly.

[0089] The secondary sun gear 301 is splinedly connected to the primary planetary carrier 204. The secondary planetary gear 302, secondary planetary shaft, rolling bearing, and secondary planetary carrier 304 are assembled together as a whole by elastic retaining rings. The secondary internal gear ring 303 is bolted to the primary gear ring connecting seat and the secondary mounting seat 107. The secondary sun gear 301, secondary internal gear ring 303, and secondary planetary gear 302 mesh with each other to form the secondary planetary gear 302 system assembly.

[0090] The third-stage sun gear 401 is splined to the second-stage planetary carrier 304. The third-stage sun gear 401 passes through the inner hole of the fourth-stage sun gear 501. The right end face of the third-stage sun gear 401 contacts the left end face of the climbing gear shaft for axial positioning.

[0091] The third-stage planetary shaft and the third-stage planetary carrier 404 are fixedly assembled with bolts. The rolling bearing is mounted on the third-stage planetary shaft via a step on the third-stage planetary shaft. The third-stage planetary gear 402 and the rolling bearing are positioned and assembled together by elastic retaining rings. The third-stage internal gear ring 403 is splined to the fourth-stage sun gear 501 and fixed together by retaining rings at both ends of the spline.

[0092] The fourth-stage planetary shaft and the fourth-stage planetary carrier 504 are fixedly assembled by interference fit. The fourth-stage planetary carrier 504 is fixed to the middle housing 102 by bolts to the fourth-stage mounting base 108. The rolling bearing is mounted on the fourth-stage planetary shaft via a step on the fourth-stage planetary shaft. The fourth-stage planetary gear 502 and the rolling bearing are positioned and assembled together by elastic retaining rings. The fourth-stage internal gear ring 503 is splined to the third-stage planetary carrier 404 and fixed together by retaining rings at both ends of the spline.

[0093] The climbing gear shaft is splined to the right end face of the third-stage planetary carrier 404. A rolling bearing is fitted in the middle of the climbing gear shaft, and the rolling bearing is connected to the mounting sleeve 103. A rolling bearing is fitted on the right side of the climbing gear shaft and connected to the bearing housing.

[0094] The first and second levels form an NGW planetary structure, while the third and fourth levels form a closed planetary structure.

[0095] Power is split through a three-stage planetary assembly, with power transmitted to the third-stage planetary shaft and the third-stage internal gear ring 403. The third-stage planetary shaft is bolted to the third-stage planetary carrier 404, transferring a portion of the power to it. The third-stage internal gear ring 403 then transmits power to the fourth-stage planetary assembly via splines, and the fourth-stage internal gear ring 503 further transmits power back to the third-stage planetary carrier 404 via splines. Finally, the two power streams merge on the third-stage planetary carrier 404.

[0096] The three-stage planetary carrier 404 transmits power to the climbing gear shaft via splines. Part of the power is transmitted in the third stage, and another part in the fourth stage, shortening the power transmission path and improving gearbox efficiency.

[0097] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0098] The enclosed planetary structure lifting gearbox for marine platforms provided in this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the solution and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A closed planetary structure lifting gearbox for an offshore platform, characterized in that, include: Box assembly (1), one end of which is provided with an input shaft (6) and the other end with an output shaft (7); The transmission assembly includes an NGW planetary transmission assembly, a three-stage planetary gear system (4), and a four-stage planetary gear system (5). The input shaft (6) transmits power to the three-stage planetary gear system (4) through the NGW planetary transmission assembly. Part of the power is directly transmitted to the output shaft (7) through the planet carrier in the three-stage planetary gear system (4), and the other part of the power is transmitted to the planet carrier through the internal gear ring of the three-stage planetary gear system (4) and the four-stage planetary gear system (5) and then transmitted to the output shaft (7).

2. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 1, characterized in that, The enclosure assembly (1) includes a front enclosure (101), a middle enclosure (102), and a mounting cylinder (103), and the enclosure assembly (1) is a sealed enclosure.

3. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 2, characterized in that, The input shaft (6) is rotatably mounted on the front housing (101), and the output shaft (7) is rotatably mounted inside the mounting cylinder (103).

4. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 2, characterized in that, A vent cap (104) and an oil plug (105) are installed on the middle box (102).

5. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 2, characterized in that, The NGW planetary transmission assembly includes a first-stage planetary gear system (2), which includes a first-stage sun gear (201), a first-stage planetary gear (202), a first-stage internal gear ring (203), and a first-stage planet carrier (204). The input shaft (6) is fixedly connected to the first-stage sun gear (201), and the first-stage internal gear ring (203) is fixed on the housing assembly (1).

6. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 5, characterized in that, The NGW planetary transmission assembly also includes a secondary planetary gear system (3), which includes a secondary sun gear (301), a secondary planetary gear (302), a secondary internal gear ring (303), and a secondary planetary carrier (304). The secondary sun gear (301) is fixedly connected to the primary planetary carrier (204), and the secondary internal gear ring (303) is fixed on the housing assembly (1).

7. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 6, characterized in that, The three-stage planetary gear system (4) includes a three-stage sun gear (401), a three-stage planet gear (402), a three-stage internal gear ring (403), and a three-stage planet carrier (404). The three-stage sun gear (401) is fixedly connected to the two-stage planet carrier (304), and the three-stage planet carrier (404) is fixedly connected to the output shaft (7).

8. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 7, characterized in that, The four-stage planetary gear system (5) includes a four-stage sun gear (501), a four-stage planet gear (502), a four-stage internal gear ring (503), and a four-stage planet carrier (504). The four-stage sun gear (501) meshes with the three-stage internal gear ring (403) for transmission. The four-stage planet carrier (504) is fixed to the housing assembly (1). The four-stage internal gear ring (503) meshes with the three-stage planet carrier (404).

9. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 8, characterized in that, A connecting shaft (405) is coaxially fixed on the third-stage sun gear (401), and the fourth-stage sun gear (501) is fitted on the connecting shaft (405) and placed between the third-stage sun gear (401) and the fourth-stage sun gear (501).

10. The enclosed planetary structure lifting gearbox for offshore platforms according to claim 6, characterized in that, The housing assembly (1) also includes a primary mounting base (106), a secondary mounting base (107), and a quaternary mounting base (108). The primary mounting base (106), the secondary mounting base (107), and the quaternary mounting base (108) are detachably mounted to the housing assembly (1). The primary mounting base (106) is connected to the primary internal gear ring (203), the secondary mounting base (107) is connected to the secondary internal gear ring (303), and the quaternary mounting base (108) is connected to the quaternary planetary gear (502).

Images