A gear reduction mechanism for a hydraulic propeller

Abstract

This application discloses a gear reduction mechanism for a hydraulic propeller, relating to the field of gear reducer technology. It includes an input shaft system, an intermediate shaft system, an output shaft system, a front housing system, a rear housing system, and a speed governor. A primary driving gear on the input shaft meshes with a primary driven gear on the intermediate shaft, and a secondary driving gear on the intermediate shaft meshes with a secondary driven gear on the output shaft, forming a two-stage reduction transmission path. The speed governor is fixed to the rear housing and connected to the intermediate shaft. Pressurized oil enters the hydraulic propeller through a pressurized oil inlet passage, the speed governor, a second pressurized oil passage, a first pressurized oil passage, and the center hole of the output shaft. The mechanism includes a first sealing ring, a second sealing ring, a bidirectional oil seal on the output shaft, a bidirectional oil seal on the intermediate shaft, a first drain passage, and a second drain passage, used to achieve pressurized oil sealing, oil drainage, and lubricant isolation. The output shaft is equipped with an axial limiting structure consisting of a thrust ring and a bushing, used to withstand the axial tension of the propeller and prevent the output shaft from disengaging.

Description

Technical Field

[0001] This application relates to the field of gear reducer technology, and more particularly to a gear reduction mechanism for a hydraulic propeller. Background Technology

[0002] Currently, when using fuel-powered piston aircraft engines for drones, the crankshaft output speed is typically higher than the suitable operating speed of the propeller. For hydraulic variable-pitch propellers, in addition to a gear reduction mechanism to reduce speed and transmit torque, the engine and propeller also need to provide driving force to the governor and deliver pressurized oil to the variable-pitch cylinder inside the propeller hub to drive the blades to complete the pitch change action.

[0003] To address the aforementioned transmission and oil supply requirements of hydraulic variable pitch propellers, existing systems typically place a reducer between the engine and the propeller, which then reduces the engine's power output. The governor, acting as a pressure and flow regulator for the variable pitch hydraulic oil, usually obtains driving force through the engine crankshaft, pulleys, or gear pairs. The hydraulic oil output from the governor or hydraulic pump is then transported to the propeller's variable pitch mechanism via external oil lines, and subsequently enters the variable pitch cylinder.

[0004] In existing hydraulic variable-pitch propeller systems, the reduction gear, governor drive, and hydraulic oil delivery are mostly distributed. The reducer mainly handles power reduction and torque transmission, the governor has a separate drive path, and the hydraulic oil needs to be delivered via external oil pipelines. This results in a large number of components, long connection paths, and limitations on the overall installation space and weight control. The external oil circuits and separate drive structure increase assembly steps and the amount of disassembly and assembly work during maintenance, which is not conducive to the compact layout of the UAV power system.

[0005] Therefore, the present invention provides a gear reduction mechanism for a hydraulic propeller to overcome the shortcomings of the prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a gear reduction mechanism for hydraulic propellers, which aims to solve the problems of the dispersed arrangement of reduction transmission, governor drive and pressure oil delivery in existing hydraulic variable pitch propeller systems, resulting in large size and weight of the mechanism, complex oil circuit connection and high assembly and maintenance costs.

[0007] This invention provides the following solution:

[0008] A gear reduction mechanism for a hydraulic propeller includes an input shaft system, an intermediate shaft system, an output shaft system, a front housing system, a rear housing system, and a speed governor.

[0009] The input shaft system includes an input shaft, on which a primary drive gear is provided, and the primary drive gear meshes with a primary driven gear provided on the intermediate shaft of the intermediate shaft system;

[0010] The intermediate shaft is fixedly connected to the secondary drive gear via a spline. The secondary drive gear meshes with the secondary driven gear in the output shaft system. The secondary driven gear is fixed to the output shaft.

[0011] The output shaft has a central hole inside, and the output shaft is supported by the front housing in the front housing system and the rear housing in the rear housing system through the front bearing and the rear bearing, respectively.

[0012] The rear housing is fixed with a speed regulator, which is connected to the intermediate shaft. The oil inlet of the speed regulator is connected to the pressure oil inlet passage, and the oil outlet of the speed regulator is connected to the second pressure oil passage. The second pressure oil passage is connected to the first pressure oil passage, and the first pressure oil passage is connected to the center hole of the output shaft.

[0013] Preferably, a front bearing is fitted around the outer periphery of the front journal of the input shaft, and a rear bearing is fitted around the outer periphery of the rear journal of the input shaft.

[0014] The input shaft front bearing is installed in the front housing, the input shaft rear bearing is installed in the rear housing, and an input shaft oil seal is provided at the position where the input shaft passes through the front housing.

[0015] Preferably, a front bearing for the intermediate shaft is fitted around the outer periphery of the front journal of the intermediate shaft, and a rear bearing for the intermediate shaft is fitted around the outer periphery of the rear journal of the intermediate shaft.

[0016] The intermediate shaft front bearing is installed in the front housing, the intermediate shaft rear bearing is installed in the rear housing, and the rear end of the intermediate shaft is provided with an internal spline that mates with the external spline of the speed controller.

[0017] Preferably, the front bearing of the output shaft is sleeved on the outer periphery of the front journal of the output shaft, the rear bearing of the output shaft is sleeved on the outer periphery of the rear journal of the output shaft, and an output shaft oil seal is provided at the position where the output shaft passes through the rear housing.

[0018] Preferably, a bushing is provided around the outer periphery of the output shaft, and the bushing is located between the rear bearing of the output shaft and the thrust ring;

[0019] The output shaft is provided with an annular groove, the thrust ring is embedded in the annular groove, the thrust ring abuts against the bushing, and the bushing abuts against the rear bearing of the output shaft.

[0020] Preferably, the first pressure oil passage is disposed within the front housing, and the first sealing ring and the second sealing ring are disposed between the output shaft and the front housing and located in the area where the first pressure oil passage leads to the central hole of the output shaft. The first sealing ring and the second sealing ring are arranged at intervals along the axial direction of the output shaft.

[0021] Preferably, a bidirectional oil seal for the output shaft is provided on the side of the sealing ring two away from the pressure oil passage one, and a cavity is formed between the sealing ring two and the bidirectional oil seal for the output shaft. The front housing is provided with an oil drain passage one that communicates with the cavity.

[0022] Preferably, the pressure oil inlet passage is disposed inside the rear housing, the second pressure oil passage is disposed inside the rear housing, and the second pressure oil passage communicates with the first pressure oil passage at the joint surface between the rear housing and the front housing.

[0023] Preferably, a bidirectional oil seal for the intermediate shaft is provided between the intermediate shaft and the rear housing, and the side of the bidirectional oil seal for the intermediate shaft near the speed controller forms a cavity, and the rear housing is provided with an oil drain passage that communicates with the cavity.

[0024] Preferably, the end of the output shaft is provided with a flange for connecting a hydraulic propeller, the central hole of the output shaft extends along the axial direction of the output shaft, and the outlet of the central hole of the output shaft faces the hydraulic propeller;

[0025] The secondary driven gear is fixed to the output shaft, and the pressure oil passage is connected to the inlet of the central hole of the output shaft.

[0026] The above solution achieves the following beneficial technical effects:

[0027] This invention forms a two-stage gear transmission structure through an input shaft system, an intermediate shaft system, and an output shaft system. The first-stage driving gear on the input shaft meshes with the first-stage driven gear on the intermediate shaft, and the second-stage driving gear meshes with the second-stage driven gear. This allows the high-speed power input from the engine to be transmitted to the hydraulic propeller via the output shaft after passing through the two-stage gear transmission. As a result, the reduction transmission path is concentrated in the housing formed by the front and rear shells, reducing the installation space occupied by separately setting external reduction transmission components.

[0028] This invention fixes the governor on the rear housing and connects the governor to the intermediate shaft drive. At the same time, a pressure oil transmission path is formed through the pressure oil inlet passage, pressure oil passage two, pressure oil passage one, and the center hole of the output shaft. This integrates the governor's drive structure and hydraulic oil transmission structure into the gear reduction mechanism, reducing the need for a separate external drive structure and external oil pipelines for the governor, and facilitating the assembly and connection between the engine and the hydraulic propeller.

[0029] This invention provides a sealing ring 1 and a sealing ring 2 in the area where the pressure oil passage 1 leads to the center hole of the output shaft, and provides a bidirectional oil seal for the output shaft on the side of the sealing ring 2 away from the pressure oil passage 1. At the same time, a bidirectional oil seal for the intermediate shaft and a drain oil passage 2 are provided at the rear housing, so that a sealed isolation is formed between the pressure oil delivery area and the lubricating oil cavity, and the leaked pressure oil is discharged through the drain oil passage 1 and the drain oil passage 2, reducing the possibility of pressure oil entering the lubricating oil cavity and lubricating oil entering the drain area. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of the developed shaft teeth of the present invention.

[0031] Figure 2 This is a schematic diagram of the rear external structure and the installation position of the speed controller of the present invention.

[0032] Figure 3 This is a schematic diagram of the external structure of the housing and the location of the two pressure oil passages of the present invention.

[0033] Figure 4 This is a schematic diagram of the gear transmission structure and the location of the pressure oil passage of the present invention.

[0034] Among them, 10. Input shaft system; 11. Input shaft; 12. Input shaft front bearing; 13. Input shaft rear bearing; 20. Intermediate shaft system; 21. Intermediate shaft; 22. Secondary drive gear; 23. Intermediate shaft front bearing; 24. Intermediate shaft rear bearing; 30. Output shaft system; 31. Output shaft; 32. Output shaft rear bearing; 33. Bushing; 34. Thrust ring; 36. Secondary driven gear; 37. Output shaft front bearing; 40. Front housing system; 41. Input shaft oil seal; 42. Sealing ring one; 43. Sealing ring two; 44. Output shaft bidirectional oil seal; 45. Pressure oil passage one; 46. Front housing; 47. Drain oil passage one; 50. Rear housing system; 51. Intermediate shaft bidirectional oil seal; 52. Output shaft oil seal; 53. Rear housing; 54. Pressure oil passage two; 55. Pressure oil inlet passage; 56. Drain oil passage two; 60. Speed ​​governor. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] See attached document Figure 1This invention provides a gear reduction mechanism for a hydraulic propeller, including an input shaft system 10. The input shaft system 10 receives power output from an engine. The input shaft system 10 and an intermediate shaft system 20 are connected via a primary gear to form a first-stage transmission relationship. The intermediate shaft system 20 and an output shaft system 30 are connected via a secondary gear to form a second-stage transmission relationship. The output shaft system 30 outputs reduced power to the hydraulic propeller. The output shaft system 30 is supported by a front housing system 40 and a rear housing system 50. A speed governor 60 is installed in the rear housing system 50 and is connected to the intermediate shaft system 20. Pressure oil transmission channels are provided within the front housing system 40 and the rear housing system 50, allowing pressure oil to pass through the speed governor 60 and enter the central hole of the output shaft 31, and then enter the hydraulic propeller connected to the output shaft 31 through the central hole of the output shaft 31.

[0037] When the UAV uses a fuel-powered piston aircraft engine, the engine crankshaft output speed is between 5000 rpm and 7000 rpm or higher. The hydraulic propeller operates at a lower speed than the engine crankshaft output speed; therefore, a gear reduction mechanism for the hydraulic propeller is installed between the engine and the hydraulic propeller. Within the same mechanism, the gear reduction transmission path, the governor 60 drive mounting structure, the high-pressure oil transmission channel, the high-pressure dynamic seal structure for rotating parts, and the oil drain structure are arranged. This allows the input shaft system 10 to receive engine power, the intermediate shaft system 20 to handle the reduction transmission and drive the governor 60, and the output shaft system 30 to handle the power output after reduction and the central transmission of pressurized oil.

[0038] The input shaft system 10 includes an input shaft 11, a front input shaft bearing 12, and a rear input shaft bearing 13. The input shaft 11 is arranged along its own axis, and one end of the input shaft 11 is provided with an external spline for receiving engine power. A single-stage drive gear is mounted on the input shaft 11. The front input shaft bearing 12 is sleeved on the outer circumference of the front journal of the input shaft 11, and the rear input shaft bearing 13 is sleeved on the outer circumference of the rear journal of the input shaft 11. The front input shaft bearing 12 is installed within a front housing 46, and the rear input shaft bearing 13 is installed within a rear housing 53, allowing the input shaft 11 to rotate relative to the front housing 46 and the rear housing 53. The front input shaft bearing 12 and the rear input shaft bearing 13 are spaced apart axially on the input shaft 11 to provide radial support for the input shaft 11 and limit axial deviation of the input shaft 11 under gear meshing stress.

[0039] The intermediate shaft system 20 includes an intermediate shaft 21, a secondary drive gear 22, a front intermediate shaft bearing 23, and a rear intermediate shaft bearing 24. The intermediate shaft 21 is arranged parallel to the input shaft 11, and a primary driven gear is mounted on the intermediate shaft 21, meshing with the primary drive gear on the input shaft 11. The secondary drive gear 22 is fixedly connected to the intermediate shaft 21 via a spline and rotates synchronously with the intermediate shaft 21. The front intermediate shaft bearing 23 is fitted onto the outer circumference of the front journal of the intermediate shaft 21, and the rear intermediate shaft bearing 24 is fitted onto the outer circumference of the rear journal of the intermediate shaft 21. The front intermediate shaft bearing 23 is installed within the front housing 46, and the rear intermediate shaft bearing 24 is installed within the rear housing 53, allowing the intermediate shaft 21 to rotate along a fixed axis when power is transmitted from the input shaft 11. An internal spline is provided at the rear end of the intermediate shaft 21, and a speed regulator 60 is provided with an external spline that mates with the internal spline of the intermediate shaft 21. The speed regulator 60 is connected to the intermediate shaft 21 via the external spline.

[0040] The output shaft system 30 includes an output shaft 31, a rear output shaft bearing 32, a bushing 33, a thrust ring 34, a secondary driven gear 36, and a front output shaft bearing 37. The output shaft 31 is arranged parallel to the input shaft 11 and the intermediate shaft 21. A flange for connecting a hydraulic propeller is provided at the end of the output shaft 31. A central hole is provided inside the output shaft 31, extending axially along the output shaft 31, for delivering pressurized oil to the hydraulic propeller connected to the output shaft 31. The front output shaft bearing 37 is sleeved on the outer circumference of the front journal of the output shaft 31, and the rear output shaft bearing 32 is sleeved on the outer circumference of the rear journal of the output shaft 31. The output shaft 31 is supported by the front housing 46 and the rear housing 53, respectively, via the front output shaft bearing 37 and the rear output shaft bearing 32. The secondary driven gear 36 is fixed to the output shaft 31 and meshes with the secondary driving gear 22. The secondary driven gear 36 receives power transmitted by the secondary driving gear 22 and drives the output shaft 31 to rotate.

[0041] A bushing 33 is fitted around the outer circumference of the output shaft 31 and is located between the output shaft rear bearing 32 and the thrust ring 34. The output shaft 31 has an annular groove, and the thrust ring 34 is embedded within this groove. When the hydraulic propeller rotates, it generates an axial tension on the output shaft 31, causing the output shaft 31 to tend to move outward along its axial direction. As the output shaft 31 moves outward, the thrust ring 34 embedded in the annular groove abuts against the bushing 33. The thrust ring 34 transmits the axial tension on the output shaft 31 to the bushing 33, which then transmits it to the output shaft rear bearing 32. The output shaft rear bearing 32 then transmits the axial tension to the rear housing 53. Through the axial force transmission path formed by the thrust ring 34, bushing 33, output shaft rear bearing 32, and rear housing 53, the output shaft 31 is prevented from disengaging from the gear reduction mechanism used in the hydraulic propeller.

[0042] The front housing system 40 includes an input shaft oil seal 41, a first sealing ring 42, a second sealing ring 43, an output shaft bidirectional oil seal 44, a first pressure oil passage 45, a front housing 46, and a first drain oil passage 47. The front housing 46 is located at the front of the input shaft system 10, the intermediate shaft system 20, and the output shaft system 30. The front housing 46 has internal holes for mounting the input shaft front bearing 12, the intermediate shaft front bearing 23, and the output shaft front bearing 37. The input shaft oil seal 41 is located where the input shaft 11 passes through the front housing 46. The inner circumference of the input shaft oil seal 41 mates with the outer circumference of the input shaft 11, and the outer circumference of the input shaft oil seal 41 mates with the front housing 46, thus preventing the leakage of lubricating oil from the gear reduction mechanism of the hydraulic propeller through the gap between the input shaft 11 and the front housing 46. Pressure oil passage 45 is located inside the front housing 46. One end of pressure oil passage 45 is connected to pressure oil passage 54 in the rear housing system 50 at the housing mating surface, and the other end of pressure oil passage 45 is connected to the center hole of the output shaft 31.

[0043] Sealing ring 42 and sealing ring 43 are disposed between the output shaft 31 and the front housing 46, and located in the area where the pressure oil passage 45 leads to the center hole of the output shaft 31. Sealing ring 42 and sealing ring 43 are spaced apart axially along the output shaft 31, providing a high-pressure dynamic seal at the point where the pressure oil passage 45 supplies oil to the center hole of the output shaft 31. When the output shaft 31 operates, it rotates relative to the front housing 46. Pressure oil enters the rotating center hole of the output shaft 31 from the pressure oil passage 45 in the stationary front housing 46. Therefore, sealing ring 42 and sealing ring 43 are located at the junction of the stationary and rotating oil passages. Sealing ring 42 and sealing ring 43 limit high-pressure oil leakage along the outer circumference of the output shaft 31 at the junction and maintain pressure oil transmission to the center hole of the output shaft 31.

[0044] A bidirectional oil seal 44 for the output shaft is disposed between the output shaft 31 and the front housing 46, located on the side of the second sealing ring 43 away from the first pressure oil passage 45. Under high-pressure dynamic sealing conditions, a small amount of pressurized oil is allowed to enter the cavity between the second sealing ring 43 and the bidirectional oil seal 44. The bidirectional oil seal 44 prevents pressurized oil in the cavity from entering the lubrication cavity of the gear reduction mechanism for the hydraulic propeller. A drain oil passage 47 is disposed on the front housing 46 and communicates with the cavity between the second sealing ring 43 and the bidirectional oil seal 44, allowing pressurized oil entering the cavity to be discharged through the drain oil passage 47. The bidirectional oil seal 44 also prevents lubricating oil from the gear reduction mechanism for the hydraulic propeller from entering the drain oil passage 47 and leaking out from it.

[0045] The rear housing system 50 includes an intermediate shaft bidirectional oil seal 51, an output shaft oil seal 52, a rear housing 53, a second pressure oil passage 54, a second pressure oil inlet passage 55, and a second oil drain passage 56. The rear housing 53 is located behind the input shaft system 10, the intermediate shaft system 20, and the output shaft system 30. The rear housing 53 is interconnected with the front housing 46 and forms an internal cavity for accommodating gears, bearings, and lubricating oil. The rear housing 53 has internal holes for mounting the input shaft rear bearing 13, the intermediate shaft rear bearing 24, and the output shaft rear bearing 32. The output shaft oil seal 52 is located where the output shaft 31 passes through the rear housing 53. The inner circumference of the output shaft oil seal 52 mates with the outer circumference of the output shaft 31, and the outer circumference of the output shaft oil seal 52 mates with the rear housing 53, thus preventing lubricating oil inside the rear housing 53 from leaking out through the gap between the output shaft 31 and the rear housing 53.

[0046] The speed governor 60 is fixed to the rear housing 53, and its mounting surface is in contact with the outer mounting surface of the rear housing 53. The oil inlet of the speed governor 60 is connected to the pressure oil inlet passage 55, and its oil outlet is connected to the second pressure oil passage 54. The pressure oil inlet passage 55 is located inside the rear housing 53 and is used to guide externally input pressure oil to the speed governor 60. The second pressure oil passage 54 is located inside the rear housing 53 and is used to receive the pressure oil regulated by the speed governor 60. The second pressure oil passage 54 connects to the first pressure oil passage 45 at the mating surface between the rear housing 53 and the front housing 46, allowing pressure oil to enter the front housing 46 from the rear housing 53 and then continue flowing into the center hole of the output shaft 31.

[0047] An intermediate shaft bidirectional oil seal 51 is disposed between the intermediate shaft 21 and the rear housing 53, and located between the governor 60 and the internal cavity of the gear reduction mechanism for the hydraulic propeller. When the governor 60 is operating, pressurized oil exists inside the governor 60 and at the connection point between the governor 60 and the rear housing 53. The intermediate shaft bidirectional oil seal 51 prevents pressurized oil at the governor 60 from entering the lubrication chamber of the gear reduction mechanism for the hydraulic propeller along the gap between the intermediate shaft 21 and the rear housing 53. A second drain passage 56 is disposed in the rear housing 53 and communicates with the cavity of the intermediate shaft bidirectional oil seal 51 near the governor 60, allowing leaking pressurized oil formed on the side of the intermediate shaft bidirectional oil seal 51 near the governor 60 during governor operation to be discharged through the second drain passage 56. The intermediate shaft bidirectional oil seal 51 also prevents lubricating oil inside the gear reduction mechanism for the hydraulic propeller from entering the governor 60 mounting area or the second drain passage 56 from the gap between the intermediate shaft 21 and the rear housing 53.

[0048] See attached document Figure 2 The rear end of the output shaft 31 is located Figure 2In the upper region, the governor 60 is fixed to the rear outer surface of the rear housing 53. Pressure oil passage 2 54 extends within the rear housing 53 and connects to the oil outlet of the governor 60. The location of drain oil passage 1 47 corresponds to the drain path in the front housing system 40. The governor 60 is mounted on the rear housing 53 and directly driven by the intermediate shaft 21 via a spline. After the governor 60 is fixed to the rear housing 53, the pressure oil inlet passage 55, the governor 60, and pressure oil passage 2 54 form an interconnected oil circuit structure, allowing for continuous transmission of pressure oil within the rear housing 53, including entry, regulation, and output.

[0049] See attached document Figure 3 The location of pressure oil passage 2 54 is shown on the outer contour of the gear reduction mechanism for the hydraulic propeller. Pressure oil passage 2 54 corresponds to the pressure oil delivery structure inside the rear housing system 50. The front housing 46 and the rear housing 53 are connected to form an integral outer housing contour. The front housing system 40 and the rear housing system 50 are connected to pressure oil passage 1 45 and pressure oil passage 2 54 through the housing mating surface. After pressure oil is output from the governor 60, it enters pressure oil passage 1 45 through the housing mating surface, and then pressure oil passage 1 45 guides the pressure oil into the center hole of the output shaft 31. The pressure oil delivery path is set inside the gear reduction mechanism for the hydraulic propeller.

[0050] See attached document Figure 4 The diagram illustrates the gear meshing relationship between the input shaft system 10, the intermediate shaft system 20, and the output shaft system 30. The primary drive gear on the input shaft 11 meshes with the primary driven gear on the intermediate shaft 21, and the secondary drive gear 22 on the intermediate shaft 21 meshes with the secondary driven gear 36 on the output shaft 31. Engine power enters through the input shaft 11 and is transmitted sequentially through the primary drive gear, the primary driven gear, the secondary drive gear 22, and the secondary driven gear 36 to the output shaft 31. The secondary drive gear 22 is fixedly connected to the intermediate shaft 21 via a spline, and the secondary driven gear 36 is fixedly connected to the output shaft 31, thus transmitting power from the intermediate shaft 21 to the output shaft 31. Pressure oil passage 24 is located within the housing area where the gear transmission structure is situated and communicates with pressure oil passage 1 45. The gear transmission structure and the pressure oil delivery structure are arranged in separate sections within the housing.

[0051] Input shaft 11, input shaft front bearing 12, input shaft rear bearing 13, intermediate shaft 21, intermediate shaft front bearing 23, intermediate shaft rear bearing 24, output shaft 31, output shaft front bearing 37, and output shaft rear bearing 32 are respectively installed in corresponding support positions in front housing 46 and rear housing 53. After front housing 46 is connected to rear housing 53, input shaft front bearing 12 and input shaft rear bearing 13 jointly define the rotation axis of input shaft 11, intermediate shaft front bearing 23 and intermediate shaft rear bearing 24 jointly define the rotation axis of intermediate shaft 21, and output shaft front bearing 37 and output shaft rear bearing 32 jointly define the rotation axis of output shaft 31. The axes of input shaft 11, intermediate shaft 21, and output shaft 31 are arranged parallel to each other, so that the meshing center distance of each gear is maintained within the position range defined by the corresponding housing hole positions. The bearing support structure is used to bear the radial load generated by gear meshing and to maintain a stable meshing position of the transmission gears during meshing.

[0052] When the gear reduction mechanism for the hydraulic propeller is in operation, the engine power is input through the external spline of the input shaft 11. As the input shaft 11 rotates, the primary drive gear on the input shaft 11 rotates synchronously and drives the primary driven gear on the intermediate shaft 21. The primary driven gear drives the intermediate shaft 21 to rotate, and the intermediate shaft 21 drives the secondary drive gear 22, which is fixedly connected to the intermediate shaft 21 via a spline. The secondary drive gear 22 drives the secondary driven gear 36 to rotate, and the secondary driven gear 36 drives the output shaft 31 to rotate. The output shaft 31 transmits power to the hydraulic propeller through the end flange. Through the meshing of the primary drive gear and the primary driven gear, and the meshing of the secondary drive gear 22 and the secondary driven gear 36, the high-speed power input from the engine is converted into a low-speed power output suitable for the operation of the hydraulic propeller.

[0053] The intermediate shaft 21 drives the governor 60 while simultaneously undertaking gear reduction transmission. The external spline of the governor 60 connects to the internal spline of the intermediate shaft 21; when the intermediate shaft 21 rotates, the input end of the governor 60 rotates with it. External pressurized oil enters the rear housing 53 through the pressurized oil inlet passage 55, and then enters the governor 60. The governor 60 regulates the pressure and flow rate of the incoming oil, and the regulated pressurized oil enters the second pressurized oil passage 54. The second pressurized oil passage 54 communicates with the first pressurized oil passage 45 at the mating surface of the front housing 46 and the rear housing 53, and pressurized oil enters the first pressurized oil passage 45 from the second pressurized oil passage 54. The first pressurized oil passage 45 guides the pressurized oil into the center hole of the output shaft 31, and the pressurized oil enters the hydraulic propeller connected to the output shaft 31 along the center hole of the output shaft 31 to drive the pitch-changing cylinder inside the hydraulic propeller, causing the hydraulic propeller to perform blade pitch-changing action.

[0054] During the process of pressurized oil entering the central hole of output shaft 31 from pressurized oil passage 45, output shaft 31 is rotating while front housing 46 is relatively fixed. Sealing ring 42 and sealing ring 43 are located at the junction of pressurized oil passage 45 and the central hole of output shaft 31 to seal and maintain pressure on the high-pressure oil. Sealing ring 42 and sealing ring 43 form a double-seal structure along the axial direction of output shaft 31, allowing pressurized oil to be guided into the central hole of output shaft 31 within the confined space between them. Sealing ring 42 and sealing ring 43, together with output shaft 31 and front housing 46, form a high-pressure dynamic seal, ensuring that pressurized oil can still enter the central hole of output shaft 31 from pressurized oil passage 45 even when output shaft 31 is rotating.

[0055] Under the high-pressure dynamic sealing operation of sealing ring 42 and sealing ring 43, a small amount of pressurized oil enters the cavity between sealing ring 43 and the output shaft bidirectional oil seal 44. The output shaft bidirectional oil seal 44 is located between the cavity and the lubricating oil cavity of the gear reduction mechanism used for the hydraulic propeller. One side of the output shaft bidirectional oil seal 44 prevents pressurized oil from entering the lubricating oil cavity, and the other side prevents lubricating oil from entering the drain area. The cavity between sealing ring 43 and the output shaft bidirectional oil seal 44 is connected to drain passage 47, and the pressurized oil entering the cavity is discharged through drain passage 47. Thus, the pressurized oil leakage path is isolated from the lubricating oil cavity by the output shaft bidirectional oil seal 44, and the lubricating oil leakage path is also isolated from the pressurized oil leakage path by the output shaft bidirectional oil seal 44.

[0056] When the governor 60 is in operation, the pressure oil inside the governor 60 acts on the mounting area between the governor 60 and the rear housing 53. A bidirectional oil seal 51 on the intermediate shaft is located between the intermediate shaft 21 and the rear housing 53 to isolate the pressure oil on the governor 60 side from the lubricating oil inside the gear reduction mechanism for the hydraulic propeller. Leaking pressure oil formed at the governor 60 is blocked by the bidirectional oil seal 51 and enters the corresponding cavity, which is connected to the second drain oil passage 56. The leaking pressure oil is discharged through the second drain oil passage 56. The bidirectional oil seal 51 also prevents lubricating oil from entering the governor 60 mounting area or the second drain oil passage 56 along the fit gap between the intermediate shaft 21 and the rear housing 53. Through the cooperation of the bidirectional oil seal 51 and the second drain oil passage 56, a pressure oil discharge path and a lubricating oil isolation structure are formed in the governor 60 mounting area.

[0057] Input shaft oil seal 41, output shaft oil seal 52, output shaft bidirectional oil seal 44, and intermediate shaft bidirectional oil seal 51 are respectively located at the junctions of different shaft systems and different media. Input shaft oil seal 41 is located at the input shaft 11 and is used to seal the lubricating oil boundary between the input shaft 11 and the front housing 46. Output shaft oil seal 52 is located at the rear of the output shaft 31 and is used to seal the lubricating oil boundary between the output shaft 31 and the rear housing 53. Output shaft bidirectional oil seal 44 is located between the pressure oil sealing area at the front of the output shaft 31 and the lubricating oil cavity, and is used to prevent pressure oil and lubricating oil from entering each other's areas. Intermediate shaft bidirectional oil seal 51 is located in the connection area between the speed controller 60 and the intermediate shaft 21, and is used to prevent the pressure oil at the speed controller 60 from communicating with the lubricating oil in the lubricating oil cavity. The above seals correspond to the input power shaft, output power shaft, pressure oil rotation delivery position, and speed controller 60 drive position, respectively.

[0058] The internal lubricating oil chamber of the gear reduction mechanism for a hydraulic propeller is formed by connecting a front housing 46 and a rear housing 53. The gear meshing parts in the input shaft system 10, intermediate shaft system 20, and output shaft system 30 are located within the lubricating oil chamber. During gear meshing, the primary driving gear and the primary driven gear, and the secondary driving gear 22 and the secondary driven gear 36 bear the tooth surface contact load. The lubricating oil chamber provides a lubrication environment for the gears, the front bearing 12 of the input shaft, the rear bearing 13 of the input shaft, the front bearing 23 of the intermediate shaft, the rear bearing 24 of the intermediate shaft, the front bearing 37 of the output shaft, and the rear bearing 32 of the output shaft. The pressure oil transmission path is formed by the pressure oil inlet passage 55, the speed governor 60, the second pressure oil passage 54, the first pressure oil passage 45, and the center hole of the output shaft 31. The pressure oil transmission path is isolated from the lubricating oil chamber by sealing ring 42, sealing ring 43, the output shaft bidirectional oil seal 44, and the intermediate shaft bidirectional oil seal 51.

[0059] The mating surface between the front housing 46 and the rear housing 53 has a channel interface for connecting pressure oil passage 1 45 and pressure oil passage 2 54. The outlet of pressure oil passage 2 54 and the inlet of pressure oil passage 1 45 are connected at the mating surface, allowing pressurized oil to transfer from the rear housing 53 to the front housing 46. Pressure oil passage 1 45 inside the front housing 46 extends to the inlet area of ​​the center hole of the output shaft 31, and pressure oil passage 2 54 inside the rear housing 53 extends to the oil outlet area of ​​the governor 60. The pressure oil inlet passage 55 is connected to the oil inlet position of the governor 60, allowing external pressurized oil to first enter the governor 60 and then enter pressure oil passage 2 54. Pressure oil passage 1 45, pressure oil passage 2 54, and pressure oil inlet passage 55 are all located within the housing structure, integrating the pressurized oil transmission path with the gear reduction transmission structure.

[0060] The inlet of the central hole of the output shaft 31 is connected to the pressure oil passage 45, and the outlet of the central hole of the output shaft 31 faces the hydraulic propeller. The output shaft 31 serves both as a transmission output and as a pressure oil delivery function. After the end flange of the output shaft 31 is connected to the hydraulic propeller, the rotational power of the output shaft 31 and the pressure oil in the central hole of the output shaft 31 are transmitted to the hydraulic propeller. The outer circumference of the output shaft 31 is supported by the front bearing 37 and the rear bearing 32, and the internal part of the output shaft 31 forms a pressure oil passage through the central hole. The secondary driven gear 36 is connected to the output shaft 31, allowing the output shaft 31 to obtain the reduced torque from the intermediate shaft 21; the pressure oil passage 45 is connected to the central hole of the output shaft 31, allowing the output shaft 31 to obtain the regulated pressure oil from the speed governor 60.

[0061] When the hydraulic propeller generates axial tension, the axial load on the output shaft 31 is transmitted along the output shaft 31 to the thrust ring 34. The thrust ring 34 is located in the annular groove of the output shaft 31 and forms an axial limiting relationship with the output shaft 31. The thrust ring 34 abuts against the bushing 33, the bushing 33 abuts against the rear bearing 32 of the output shaft, and the rear bearing 32 abuts against the rear housing 53. The axial load is transmitted sequentially through the thrust ring 34, the bushing 33, and the rear bearing 32 of the output shaft to the rear housing 53, which bears the force generated by the outward movement of the output shaft 31. Through the axial limiting structure, the output shaft 31 is held within the installation position defined by the front housing 46 and the rear housing 53 under the action of the hydraulic propeller tension.

[0062] When the gear reduction mechanism for the hydraulic propeller is in operation, the engine output end is connected to the external spline of the input shaft 11, and the hydraulic propeller is connected to the flange at the end of the output shaft 31. After the connection is completed, the input shaft system 10 is located at the power input end, the output shaft system 30 is located at the power output end, the intermediate shaft system 20 is located between the input shaft system 10 and the output shaft system 30, and the speed governor 60 is fixed to the rear housing 53 and is connected to the internal spline of the intermediate shaft 21.

[0063] After the engine starts, engine power enters the input shaft 11 via the external spline. The input shaft 11 rotates under the support of the front bearing 12 and the rear bearing 13, and the primary drive gear on the input shaft 11 rotates synchronously, driving the primary driven gear on the intermediate shaft 21. The intermediate shaft 21 rotates under the support of the front bearing 23 and the rear bearing 24, and the secondary drive gear 22 rotates synchronously with the intermediate shaft 21.

[0064] The secondary drive gear 22 meshes with the secondary driven gear 36, and the secondary drive gear 22 transmits the power of the intermediate shaft 21 to the secondary driven gear 36. The secondary driven gear 36 drives the output shaft 31 to rotate. The output shaft 31 rotates under the support of the front bearing 37 and the rear bearing 32 of the output shaft. The output shaft 31 outputs power to the hydraulic propeller through the end flange.

[0065] When the intermediate shaft 21 rotates, the internal spline of the intermediate shaft 21 drives the external spline of the speed governor 60 to rotate. External pressure oil enters the rear housing 53 from the pressure oil inlet passage 55 and then enters the speed governor 60. The speed governor 60 regulates the pressure and flow of the pressure oil, and the regulated pressure oil enters the second pressure oil passage 54.

[0066] The pressurized oil flows along pressure oil passage 2 54 to the mating surface between the rear housing 53 and the front housing 46, and then enters pressure oil passage 1 45 from pressure oil passage 2 54. The pressurized oil then enters the high-pressure dynamic sealing area defined by sealing ring 1 42 and sealing ring 2 43 along pressure oil passage 1 45, and from there enters the central hole of the output shaft 31. The pressurized oil flows along the central hole of the output shaft 31 into the hydraulic propeller connected to the output shaft 31, providing hydraulic oil to the pitch cylinder of the hydraulic propeller for adjusting the blade angle.

[0067] With the output shaft 31 rotating and delivering pressurized oil, sealing ring 42 and sealing ring 43 seal and maintain the pressure of the oil. Pressurized oil that seeps into the cavity between sealing ring 43 and the output shaft bidirectional oil seal 44 is discharged through drain passage 47. The output shaft bidirectional oil seal 44 prevents pressurized oil from entering the lubricating oil cavity and also prevents lubricating oil from entering drain passage 47.

[0068] When the governor 60 is in operation, the intermediate shaft bidirectional oil seal 51 prevents pressurized oil at the governor 60 from entering the lubrication chamber. Leaking pressurized oil generated at the governor 60 is discharged through the second drain passage 56. The intermediate shaft bidirectional oil seal 51 also prevents lubricating oil from entering the governor 60 mounting area or the second drain passage 56 from the mating area between the intermediate shaft 21 and the rear housing 53.

[0069] When the hydraulic propeller exerts an axial pulling force on the output shaft 31, the output shaft 31 transmits the axial pulling force to the thrust ring 34. The thrust ring 34 transmits the axial pulling force to the output shaft rear bearing 32 through the bushing 33, and the output shaft rear bearing 32 transmits the axial pulling force to the rear housing 53. The output shaft 31 is confined within its installation position by the axial limiting structure formed by the thrust ring 34, bushing 33, output shaft rear bearing 32, and rear housing 53.

[0070] Through the above working process, the input shaft system 10, intermediate shaft system 20, and output shaft system 30 complete the reduction transmission of engine power to the hydraulic propeller; the intermediate shaft 21 simultaneously drives the governor 60, so that the governor 60 is installed on the rear housing 53 and directly driven by the intermediate shaft 21; the pressure oil inlet passage 55, the governor 60, the second pressure oil passage 54, the first pressure oil passage 45, and the center hole of the output shaft 31 form a pressure oil transmission path; the first sealing ring 42, the second sealing ring 43, the output shaft bidirectional oil seal 44, and the intermediate shaft bidirectional oil seal 51 form a sealed isolation between the pressure oil and the lubricating oil; the first drain passage 47 and the second drain passage 56 form a discharge path for leaking pressure oil; the thrust ring 34, the bushing 33, the output shaft rear bearing 32, and the rear housing 53 form an axial anti-disengagement structure for the output shaft 31. All the above structures together constitute a gear reduction mechanism for a hydraulic propeller.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gear reduction mechanism for a hydraulic propeller, characterized in that, It includes an input shaft system (10), an intermediate shaft system (20), an output shaft system (30), a front housing system (40), a rear housing system (50), and a speed controller (60). The input shaft system (10) includes an input shaft (11), on which a primary drive gear is provided, and the primary drive gear meshes with a primary driven gear provided on the intermediate shaft (21) in the intermediate shaft system (20); The intermediate shaft (21) is fixedly connected to the secondary drive gear (22) via a spline. The secondary drive gear (22) meshes with the secondary driven gear (36) in the output shaft system (30). The secondary driven gear (36) is fixed to the output shaft (31). The output shaft (31) has a central hole inside. The output shaft (31) is supported by the front housing (46) in the front housing system (40) and the rear housing (53) in the rear housing system (50) through the front bearing (37) and the rear bearing (32) of the output shaft, respectively. The rear housing (53) is fixed with a speed regulator (60), which is connected to the intermediate shaft (21) for transmission. The oil inlet of the speed regulator (60) is connected to the pressure oil inlet passage (55), and the oil outlet of the speed regulator (60) is connected to the second pressure oil passage (54). The second pressure oil passage (54) is connected to the first pressure oil passage (45), and the first pressure oil passage (45) is connected to the center hole of the output shaft (31).

2. The gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, The front journal of the input shaft (11) is fitted with a front bearing (12), and the rear journal of the input shaft (11) is fitted with a rear bearing (13). The input shaft front bearing (12) is installed in the front housing (46), the input shaft rear bearing (13) is installed in the rear housing (53), and an input shaft oil seal (41) is provided at the position where the input shaft (11) passes through the front housing (46).

3. A gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, The front journal of the intermediate shaft (21) is fitted with a front bearing (23), and the rear journal of the intermediate shaft (21) is fitted with a rear bearing (24). The intermediate shaft front bearing (23) is installed in the front housing (46), the intermediate shaft rear bearing (24) is installed in the rear housing (53), and the rear end of the intermediate shaft (21) is provided with an internal spline that cooperates with the external spline of the speed regulator (60).

4. A gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, The front bearing (37) of the output shaft is sleeved on the outer periphery of the front journal of the output shaft (31), the rear bearing (32) of the output shaft is sleeved on the outer periphery of the rear journal of the output shaft (31), and an output shaft oil seal (52) is provided at the position where the output shaft (31) passes through the rear housing (53).

5. A gear reduction mechanism for a hydraulic propeller according to claim 4, characterized in that, The output shaft (31) is fitted with a bushing (33) on its outer periphery, and the bushing (33) is located between the rear bearing (32) of the output shaft and the thrust ring (34); The output shaft (31) is provided with an annular groove, the thrust ring (34) is embedded in the annular groove, the thrust ring (34) abuts against the bushing (33), and the bushing (33) abuts against the rear bearing (32) of the output shaft.

6. A gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, The first pressure oil passage (45) is disposed inside the front housing (46), and the first sealing ring (42) and the second sealing ring (43) are disposed between the output shaft (31) and the front housing (46) and located in the area where the first pressure oil passage (45) leads to the central hole of the output shaft (31). The first sealing ring (42) and the second sealing ring (43) are arranged at intervals along the axial direction of the output shaft (31).

7. A gear reduction mechanism for a hydraulic propeller according to claim 6, characterized in that, The sealing ring 2 (43) is provided with an output shaft bidirectional oil seal (44) on the side away from the pressure oil passage 1 (45). A cavity is formed between the sealing ring 2 (43) and the output shaft bidirectional oil seal (44). The front shell (46) is provided with an oil drain passage 1 (47) that communicates with the cavity.

8. A gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, The pressure oil inlet channel (55) is located inside the rear shell (53), and the second pressure oil channel (54) is located inside the rear shell (53). The second pressure oil channel (54) is connected to the first pressure oil channel (45) at the joint surface between the rear shell (53) and the front shell (46).

9. A gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, An intermediate shaft bidirectional oil seal (51) is provided between the intermediate shaft (21) and the rear housing (53). The intermediate shaft bidirectional oil seal (51) forms a cavity on the side near the speed regulator (60). The rear housing (53) is provided with an oil drain passage (56) that communicates with the cavity.

10. A gear reduction mechanism for a hydraulic propeller according to claim 1, characterized in that, The output shaft (31) is provided with a flange for connecting a hydraulic propeller at its end. The central hole of the output shaft (31) extends along the axial direction of the output shaft (31), and the outlet of the central hole of the output shaft (31) faces the hydraulic propeller. The secondary driven gear (36) is fixed to the output shaft (31), and the pressure oil passage (45) is connected to the inlet of the central hole of the output shaft (31).

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