Gearbox for oil-electric double-engine ship

Abstract

The utility model discloses a gearbox for an oil-electricity double-engine ship. The gearbox comprises a box body, the diesel oil input component comprises a first input shaft, a first driving gear is sleeved on the first input shaft, and the first input shaft is provided with a first transmission gear and a first clutch; the reversing shaft part comprises a reversing shaft, a second driving gear is sleeved on the reversing shaft, the reversing shaft is provided with a second transmission gear and a second clutch, and the second transmission gear is meshed with the first transmission gear; the motor input component comprises a second input shaft, the second input shaft is sleeved with a third driving gear in an empty mode, the third driving gear is meshed with a first driven gear, the second driving gear is fixedly sleeved with the first driven gear, and the second input shaft is provided with a third clutch; the output shaft component comprises an output shaft and a second driven gear, and the second driven gear is meshed with the first driving gear and the second driving gear. According to the scheme, the diesel engine or the motor is independently used for driving, intelligent switching of the diesel engine and the motor can be achieved at any speed, oil consumption is reduced, and power performance is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to gear box technical field especially relates to a kind of oil-electricity double-drive marine gear box. BACKGROUND

[0002] At present, most of the ships are powered by diesel engines, which rotate the propeller at the stern through the bearing to generate propulsion power. The marine gear box is generally designed with a certain speed ratio, and the propeller is designed according to this speed ratio to achieve the best propulsion efficiency. However, ships such as passenger-cargo ships, engineering ships and trawl fishing vessels usually have multiple modes or speed conditions. Under the condition of a certain main engine power, the multi-condition operation of the ship will cause a significant fluctuation in the utilization rate of the main engine power, resulting in a decrease in the propeller propulsion efficiency, an increase in energy consumption, a waste of fuel, an impact on economy, and serious air pollution. The use of electric drive for hybrid power drive not only allows the diesel engine to work at an economic speed or reduces the operation of the diesel engine to solve the problems of carbon deposition, fuel waste and pollution emission, but also allows the ship to sail in pure electric mode for as much time as possible, which can significantly reduce the energy consumption and operating cost of the ship.

[0003] Patent application No. CN110316347A discloses a marine gear box with an auxiliary transmission box to meet the PTO / PTI function. The auxiliary transmission box takes power from the rear end of the main transmission clutch of the propulsion gear box to realize the PTI function. However, in this structure, the electric motor serves as an auxiliary power device, and the input power is generally much smaller than that of the diesel engine. Moreover, the input and output are horizontally arranged at the same center, which requires a large installation space. Patent application No. CN118387278A discloses a high-efficiency diesel-electric hybrid propulsion ship and its gear box. The engine is connected to the right end of the input shaft, which can be a diesel engine or a gasoline engine. The propeller is connected to the left end of the output shaft, and the electric motor is connected to the left end of the first transmission shaft, thereby driving the propeller and the electric motor to rotate at different speeds. However, this structure of the gear box cannot be applied in the reverse working condition. SUMMARY

[0004] To solve the above technical problems, the purpose of the utility model is to provide an oil-electricity double-drive marine gear box that can realize the independent driving of the propeller by the diesel engine or the electric motor. The structure of the oil-electricity double-drive marine gear box is compact.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An oil-electricity double-drive marine gear box comprises a box body and a diesel input component, a reverse shaft component, an electric motor input component and an output shaft component arranged in the box body,

[0007] The diesel input component includes a first input shaft, a first drive gear is loosely fitted at the rear end of the first input shaft, and a first transmission gear and a first clutch are arranged at the front end of the first input shaft. The first clutch is used to control the transmission between the first drive gear and the first input shaft.

[0008] The reversing axle assembly includes a reversing axle, a second drive gear is loosely fitted at the rear end of the reversing axle, and a second transmission gear and a second clutch are arranged at the front end of the reversing axle. The second clutch is used to control the transmission between the second drive gear and the reversing axle, and the second transmission gear meshes with the first transmission gear.

[0009] The motor input component includes a second input shaft, a third drive gear is loosely fitted at the front end of the second input shaft, a first driven gear meshes with the third drive gear, the first driven gear is fixedly fitted on the second drive gear, and a third clutch is arranged on the second input shaft. The third clutch is used to control the transmission between the third drive gear and the second input shaft.

[0010] The output shaft component includes an output shaft and a second driven gear fixedly sleeved on the output shaft. The second driven gear meshes with both the first driving gear and the second driving gear.

[0011] In this way, the propeller connected to the output shaft component in this gearbox can be driven by either a diesel engine or an electric motor. Because it has two power sources, a diesel engine and an electric motor, it can intelligently switch between fuel and motor at any speed, which greatly reduces fuel consumption and improves power performance.

[0012] Preferably, the system also includes hydraulic control components, which include a motor-driven pump, a solenoid-operated directional hydraulic control valve, a three-position four-way solenoid valve, and an electric pump. The motor-driven pump supplies fuel when the engine is running, while the electric pump supplies fuel when the motor is running. The solenoid-operated directional hydraulic control valve switches between diesel engine and motor drive modes and controls the engagement / disengagement of the third clutch. The three-position four-way solenoid valve controls the engagement / disengagement of the first and second clutches. When using the three-position four-way solenoid valve, it is essential to first switch the solenoid-operated hydraulic control valve to the diesel engine drive mode.

[0013] Preferably, the first transmission gear also serves as the housing of the first clutch, the first clutch is arranged inside the first transmission gear, a first piston and a first return spring for resetting the first piston are provided on one side of the first clutch, the outer friction plate of the first clutch is connected to the first transmission gear, the inner friction plate of the first clutch is connected to the first clutch seat, and the first clutch seat is connected to the first drive gear.

[0014] The second transmission gear also serves as the housing of the second clutch. The second clutch is arranged inside the second transmission gear. A second piston and a second return spring for resetting the second piston are provided on one side of the second clutch. The outer friction plate of the second clutch is connected to the second transmission gear, the inner friction plate of the second clutch is connected to the second clutch seat, and the second clutch seat is connected to the second drive gear.

[0015] Preferably, a clutch housing is fixedly mounted at the rear end of the second input shaft, and a third clutch is arranged inside the clutch housing. The clutch housing contains a third piston and a third return spring for resetting the third piston. The outer friction plate of the third clutch is connected to the clutch housing, and the inner friction plate of the third clutch is connected to the third drive gear. The third return spring is a disc spring. This allows for a more thorough separation of the inner and outer friction plates of the third clutch.

[0016] Preferably, two sliding bushings are placed between the third drive gear and the second input shaft, and an oil distribution sleeve is provided between the two sliding bushings. By using sliding bushings instead of conventionally used rolling bearings, the arrangement space is reduced and the transmission speed is increased, while the oil distribution sleeve enhances lubrication.

[0017] Preferably, the first and second drive gears are supported on the housing by two roller bearings at both ends; the first input shaft and the reverse shaft are supported on the housing by two roller bearings at both ends; the output shaft is supported on the housing by two thrust roller bearings and one roller bearing; and the second input shaft is supported on the housing by two roller bearings at both ends.

[0018] Preferably, the front end of the first input shaft is connected to the diesel engine via a first input coupling and a first high-elasticity coupling, the rear end of the output shaft is connected to the propeller via an output coupling, and the rear end of the second input shaft is provided with a second input coupling and a second high-elasticity coupling to connect to the motor.

[0019] Preferably, the first input shaft and the first input coupling are connected by a hydraulically fitted taper interference fit, the output shaft and the output coupling are connected by a hydraulically fitted taper interference fit, and the second input shaft and the second input coupling are connected by a hydraulically fitted taper interference fit. This hydraulically fitted taper interference fit connection method is easy to disassemble and makes shaft system installation more convenient.

[0020] Preferably, the first input shaft and the output shaft are arranged perpendicularly and out of center, with the first input shaft located above the output shaft, the reversing shaft located on one side of the center line between the first input shaft and the output shaft, and the second input shaft located above the output shaft. This reduces the center distance between the input and output shafts, resulting in a compact structure and minimal installation space requirements.

[0021] Preferably, the gearbox includes an upper gearbox, a middle gearbox, and a lower gearbox. The upper and middle gearboxes are horizontally separated along the centerline of the second input shaft, while the middle and lower gearboxes are obliquely separated along the centerlines of the input shaft and the reversing shaft. This design facilitates gearbox disassembly and maintenance. The upper gearbox can be lifted to remove the motor input components, while the middle gearbox can be lifted to remove the diesel input components and the reversing shaft components for maintenance such as replacing friction plates.

[0022] This utility model, by adopting the above technical solution, has the following beneficial effects:

[0023] 1. In this utility model, the propeller can be driven by either a diesel engine or an electric motor. Since it has two power sources, a diesel engine and an electric motor, it can intelligently switch between fuel and motor at any speed, which greatly reduces fuel consumption and improves power performance. The electric motor provides power when starting and driving at low speed, while the diesel engine is the main power source when driving at high speed and accelerating. At the same time, energy is collected and recovered into the battery during deceleration and braking.

[0024] 2. In this utility model, the gearbox adds a motor input component to the conventional single-input marine gearbox that bears the thrust of the propeller. The first input shaft and the output shaft are arranged vertically and out of center, with the first input shaft on top and the output shaft on the bottom. The reversing shaft is located on one side of the center line of the first input shaft and the output shaft, and the second input shaft is located above the output shaft. This reduces the center distance between the input shaft and the output shaft, resulting in a compact structure, small installation space requirements, and high degree of versatility. Attached Figure Description

[0025] Fig. 1 This is a schematic diagram of the structure of the box in this utility model;

[0026] Fig. 2 This is a cross-sectional structural diagram of the present invention;

[0027] Fig. 3 This is a simplified transmission diagram of the gearbox in this utility model.

[0028] Figure label:

[0029] 1. Connecting cover; 2. First high-elasticity coupling; 3. First input coupling; 4. First input shaft; 5. First return spring; 6. First transmission gear; 7. First clutch seat; 8. First piston; 9. First clutch; 10. First drive gear; 11. Reverse shaft; 12. Second transmission gear; 13. Second return spring; 14. Second piston; 15. Second clutch; 16. Second clutch seat; 17. First driven gear; 18. Second drive gear; 19. 20. Second input coupling; 21. Second input shaft; 22. Clutch housing; 23. Third piston; 24. Three-position four-way solenoid valve; 25. Solenoid reversing hydraulic control valve; 26. Third clutch; 27. Third return spring; 28. Third drive gear; 29. ​​Sliding bushing; 30. Oil distributor sleeve; 31. Output shaft; 32. Second driven gear; 33. Output coupling; 34. Motor-driven pump; 35. Upper housing; 36. Middle housing; 37. Lower housing. Detailed Implementation

[0030] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] like Figs. 1 to 3 As shown, this utility model discloses a dual-engine marine gearbox, including: a gearbox body and a diesel input component, a reversing axle component, a motor input component and an output shaft component disposed in the gearbox body.

[0036] The diesel input component includes a first input shaft 4, whose two ends are supported on the housing by two roller bearings. The front end of the first input shaft 4 is connected to the flywheel of the diesel engine via a first input coupling 3 and a first high-elasticity coupling 2. The first input shaft 4 and the first input coupling 3 are connected by a hydraulically fitted tapered interference fit. The connecting cover 1 is connected to the diesel engine housing. A first drive gear 10 is loosely fitted at the rear end of the first input shaft 4. The two ends of the first drive gear 10 are supported on the middle housing 36 and the lower housing 37 by two roller bearings, respectively. A first transmission gear 6 and a first clutch 9 are arranged at the front end of the first input shaft 4. The first transmission gear 6 is heat-fitted onto the front end of the first input shaft 4 and also serves as the housing of the first clutch 9. The first clutch 9 is used to control the transmission between the first drive gear 10 and the first input shaft 4.

[0037] More specifically, the first clutch 9 is arranged inside the first transmission gear 6. A first piston 8 and a first return spring 5 for resetting the first piston 8 are provided on one side of the first clutch 9. The outer friction plate of the first clutch 9 is connected to the first transmission gear 6, and the inner friction plate of the first clutch 9 is connected to the first clutch seat 7. The first clutch seat 7 is connected to the first drive gear 10.

[0038] The reversing axle assembly includes a reversing axle 11, with both ends of the reversing axle 11 supported on the middle housing 36 and the lower housing 37 respectively by two roller bearings. A second drive gear 18 is loosely fitted at the rear end of the reversing axle 11, with both ends of the second drive gear 18 also supported on the middle housing 36 and the lower housing 37 respectively by two roller bearings. A second transmission gear 12 and a second clutch 15 are arranged at the front end of the reversing axle 11. The second transmission gear 12 is heat-fitted onto the front end of the reversing axle 11 and also serves as the housing for the second clutch 15, which controls the transmission between the second drive gear 18 and the reversing axle 11. The second transmission gear 12 meshes with the first transmission gear 6.

[0039] More specifically, the second clutch 15 is arranged inside the second transmission gear 12. A second piston 14 and a second return spring 13 for resetting the second piston 14 are provided on one side of the second clutch 15. The outer friction plate of the second clutch 15 is connected to the second transmission gear 12, and the inner friction plate of the second clutch 15 is connected to the second clutch seat 16. The second clutch seat 16 is connected to the second drive gear 18.

[0040] The motor input component includes a second input shaft 21, which is supported at both ends by two roller bearings on the upper housing 35 and the middle housing 36. The rear end of the second input shaft 21 is provided with a second input coupling 20 and a second high-elasticity coupling 19, which connect to the motor shaft. The second input shaft 21 and the second input coupling 20 are connected by a hydraulically fitted tapered interference fit. A third drive gear 28 is loosely fitted at the front end of the second input shaft 21. Two sliding bushings 29 are placed between the third drive gear 28 and the second input shaft 21 to replace the rolling bearings at both ends, reducing the arrangement space and increasing the transmission speed. An oil distribution sleeve 30 is provided between the two sliding bushings 29 to enhance lubrication. A first driven gear 17 meshes with the third drive gear 28, which is thermally fitted onto the second drive gear 18. A third clutch 26 is arranged on the second input shaft 21 to control the transmission between the third drive gear 28 and the second input shaft 21.

[0041] More specifically, a clutch housing 22 is fixedly mounted at the rear end of the second input shaft 21. A third clutch 26 is arranged inside the clutch housing 22. The clutch housing 22 contains a third piston 23 and a third return spring 27 for resetting the third piston 23. The outer friction plate of the third clutch 26 is connected to the clutch housing 22, and the inner friction plate of the third clutch 26 is connected to the third drive gear 28. To ensure more thorough separation of the inner and outer friction plates of the third clutch 26, the third return spring 27 is a disc spring.

[0042] The output shaft assembly includes an output shaft 31 and a second driven gear 32 that is tapered and interference-fitted onto the output shaft 31. The output shaft 31 is supported on the lower housing 37 by two thrust roller bearings and one roller bearing. The output shaft 31 is connected to the tail shaft via an output coupling 33, and the output shaft 31 and the output coupling 33 are connected by a hydraulically fitted tapered interference fit, thereby outputting power to the propeller. The second driven gear 32 meshes with both the first driving gear 10 and the second driving gear 18.

[0043] The gearbox provided by this utility model also includes a hydraulic control component, which includes a motor-driven pump 34, an electromagnetic reversing hydraulic control valve 25, a three-position four-way solenoid valve 24, and an electric pump. The motor-driven pump 34 supplies oil when the diesel engine is driven, and the electric pump supplies oil when the electric motor is driven. The electromagnetic reversing valve 25 establishes the working and lubricating oil pressure of the hydraulic system and can be used to switch between the diesel engine drive mode and the electric motor drive mode, while controlling the engagement and disengagement of the third clutch 26. The three-position four-way solenoid valve 24 controls the engagement and disengagement of the first clutch 9 and the second clutch 15. Specifically, the electromagnetic reversing hydraulic control valve 25 is connected to the third piston 23, and the first piston 8 and the second piston 14 are connected to the three-position four-way solenoid valve 24 through a hydraulic oil chamber. When using the three-position four-way solenoid valve 24, the electromagnetic reversing hydraulic control valve 25 must first be switched to the diesel engine drive mode.

[0044] The gearbox is used as follows: (Previous)

[0045] When the electromagnetic reversing hydraulic control valve 25 is in the "diesel engine" position and the three-position four-way solenoid valve 24 is in the "stop" position, the working oil passages of the first clutch 9 on the first input shaft 4 and the second clutch 15 on the reverse shaft 11 are simultaneously switched to the return oil passage. Under the action of the first return spring 5, the first piston 8 quickly disengages from the inner and outer friction plates, and the second piston 14 quickly disengages from the inner and outer friction plates under the action of the second return spring 13. The first drive gear 10 is loosely fitted on the first input shaft 4, and the second drive gear 18 is loosely fitted on the reverse shaft 11, thus preventing them from driving the driven gear 32 on the output shaft 31 to rotate, and the propeller stops rotating. At this time, all the oil in the hydraulic system is lubricating oil, which flows through various oil passages to the lubrication points of the gearbox. The lubricating oil pressure is regulated by the lubrication valve in the lubrication valve plate assembly, ensuring stable lubrication pressure that fully meets the lubrication needs at various speeds.

[0046] When the three-position four-way solenoid valve 24 is in the "forward" position, the working oil passage of the first clutch 9 of the first input shaft 4 is opened, and the working oil pressure pushes the first piston 8 of the first clutch 9 to press the inner and outer friction plates, so that the first driving gear 10 rotates synchronously with the first input shaft 4 through the first clutch seat 7, and drives the second driven gear 32 to rotate, thereby driving the output shaft 31 and the propeller to rotate, and the ship moves forward.

[0047] When the three-position four-way solenoid valve 24 is in the "reverse" position, the working oil passage of the second clutch 15 of the reverse shaft 11 is opened. The working oil pressure pushes the second piston 14 of the second clutch 15 to press the inner and outer friction plates, so that the second drive gear 18 rotates synchronously with the reverse shaft 11 through the second clutch seat 16, and drives the second driven gear 32 to rotate in the opposite direction, thereby driving the output shaft 31 and the propeller to rotate. At this time, the ship moves backward.

[0048] When the electromagnetic reversing hydraulic control valve 25 is in the "stop" position, the working oil passage of the third clutch 26 on the second input shaft 21 switches to the return oil passage. Under the action of the third return spring 27, the third piston 23 quickly disengages from the inner and outer friction plates. The third drive gear 28 is loosely fitted on the second input shaft 21, and therefore cannot drive the first driven gear 17 on the second drive gear 18 to rotate. The second drive gear 18 does not rotate, and therefore cannot drive the second driven gear 32 on the output shaft 31 to rotate, so the propeller stops rotating. At this time, all the oil in the hydraulic system is lubricating oil, which flows through the oil passages to the lubrication points of the gearbox.

[0049] When the electromagnetic reversing hydraulic control valve 25 is in the "motor" position, the working oil passage of the third clutch 26 on the second input shaft 21 is opened. The working oil pressure pushes the piston 23 of the third clutch 26 to press the inner and outer friction plates, so that the third drive gear 28 rotates synchronously with the second input shaft 21, and drives the first driven gear 17, which is hot-fitted on the second drive gear 18, to rotate. The rotation of the second drive gear 18 drives the second driven gear 32 to rotate in the opposite direction, thereby driving the output shaft 31 and the propeller to rotate, and the ship moves forward.

[0050] When the electric motor drives the reversing motion, simply rotate the motor in the opposite direction, and the ship will move backward.

[0051] This utility model's gearbox diesel engine drive uses a three-shaft, five-gear, single-stage reduction transmission, while the electric motor drive uses a three-shaft, four-gear, two-stage reduction transmission. For example... Fig. 3As shown, the first input shaft 4 and the output shaft 31 are arranged vertically and at opposite centers, with the first input shaft 4 located above the output shaft 31. The reversing shaft 11 is located on one side of the center line between the first input shaft 4 and the output shaft 31, and the second input shaft 21 is located above the output shaft 31, resulting in a compact structural arrangement. The gearbox includes an upper gearbox 35, a middle gearbox 36, and a lower gearbox 37. The upper gearbox 35 and the middle gearbox 36 are horizontally separated along the center line of the second input shaft 21, while the middle gearbox 36 and the lower gearbox 37 are obliquely separated along the center line of the input shaft 4 and the reversing shaft 11. The motor input component is installed in the upper gearbox 35 and the middle gearbox 36, the diesel input component and the reversing shaft component are installed in the middle gearbox 36 and the lower gearbox 37, and the output shaft component is installed in the lower gearbox 37. This facilitates the disassembly and maintenance of the gearbox. The motor input component can be removed by lifting the upper gearbox 35, and the diesel input shaft component and the reversing shaft component can be removed by lifting the middle gearbox 36 for maintenance such as replacing friction plates.

[0052] All features described in the specification, appended claims and drawings, whether individually or in any combination thereof, are essential features of this utility model.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, alterations, deletions of some features, additions of features, or recombinations of features to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the innovative principles of the present invention shall still fall within the scope of the technical solutions of the present invention.

Claims

1. A hybrid marine gearbox comprising: The box and diesel input part, reverse shaft part, motor input part and output shaft part arranged in the box are characterized in that, The diesel input part comprises a first input shaft (4), the rear end of the first input shaft (4) is sleeved with a first driving gear (10), the front end of the first input shaft (4) is arranged with a first transmission gear (6) and a first clutch (9), the first clutch (9) is used for controlling the transmission between the first driving gear (10) and the first input shaft (4); The reverse shaft part comprises a reverse shaft (11), the rear end of the reverse shaft (11) is sleeved with a second driving gear (18), the front end of the reverse shaft (11) is arranged with a second transmission gear (12) and a second clutch (15), the second clutch (15) is used for controlling the transmission between the second driving gear (18) and the reverse shaft (11), the second transmission gear (12) is engaged with the first transmission gear (6); The motor input part comprises a second input shaft (21), the front end of the second input shaft (21) is sleeved with a third driving gear (28), the third driving gear (28) is engaged with a first driven gear (17), the first driven gear (17) is fixedly sleeved on the second driving gear (18), the second input shaft (21) is arranged with a third clutch (26), the third clutch (26) is used for controlling the transmission between the third driving gear (28) and the second input shaft (21); The output shaft part comprises an output shaft (31) and a second driven gear (32) fixedly sleeved on the output shaft (31), the second driven gear (32) is engaged with the first driving gear (10) and the second driving gear (18) at the same time.

2. An oil-electric dual propulsion marine gear box as claimed in claim 1, wherein, Further comprising a hydraulic control part, the hydraulic control part comprises a belt pump (34), an electromagnetic reversing hydraulic control valve (25), a three-position four-way electromagnetic valve (24) and an electric pump, wherein the belt pump (34) is used for oil supply when the diesel engine is driven, the electric pump is used for oil supply when the motor is driven, the electromagnetic reversing hydraulic control valve (25) is used for switching the diesel engine driving mode and the motor driving mode, the electromagnetic reversing hydraulic control valve (25) is used for controlling the third clutch (26) to be engaged or disengaged; the three-position four-way electromagnetic valve (24) is used for controlling the first clutch (9) and the second clutch (15) to be engaged or disengaged.

3. An oil-electric dual propulsion marine gear box as claimed in claim 2, wherein, The first transmission gear (6) is used as the shell of the first clutch (9), the first clutch (9) is arranged in the first transmission gear (6), one side of the first clutch (9) is provided with a first piston (8) and a first return spring (5) used for resetting the first piston (8), the outer friction plate of the first clutch (9) is connected with the first transmission gear (6), the inner friction plate of the first clutch (9) is connected with a first clutch seat (7), the first clutch seat (7) is connected with the first driving gear (10); The second transmission gear (12) is used as the shell of the second clutch (15), the second clutch (15) is arranged in the second transmission gear (12), one side of the second clutch (15) is provided with the second piston (14) and the second return spring (13) for resetting the second piston (14), the outer friction plate of the second clutch (15) is connected with the second transmission gear (12), the inner friction plate of the second clutch (15) is connected with the second clutch seat (16), and the second clutch seat (16) is connected with the second driving gear (18).

4. An oil-electric dual propulsion marine gearbox according to claim 2 or 3, characterised in that, The rear end of the second input shaft (21) is fixedly provided with a clutch shell (22), the third clutch (26) is arranged in the clutch shell (22), the clutch shell (22) is internally provided with the third piston (23) and the third return spring (27) for resetting the third piston (23), the outer friction plate of the third clutch (26) is connected with the clutch shell (22), and the inner friction plate of the third clutch (26) is connected with the third driving gear (28); the third return spring (27) is a disc spring.

5. An oil-electric dual propulsion marine gear case as claimed in claim 1, wherein, Two sliding shaft sleeves (29) are arranged between the third driving gear (28) and the second input shaft (21), and an oil distribution sleeve (30) is arranged between the two sliding shaft sleeves (29).

6. An oil-electric dual propulsion marine gear case as claimed in claim 1, wherein, The two ends of the first driving gear (10) and the second driving gear (18) are supported on the box body through two roller bearings; the two ends of the first input shaft (4) and the reverse shaft (11) are supported on the box body through two roller bearings; the output shaft (31) is supported on the box body through two thrust roller bearings and one roller bearing; and the two ends of the second input shaft (21) are supported on the box body through two roller bearings.

7. An oil-electric dual propulsion marine gear case as claimed in claim 1, wherein, The front end of the first input shaft (4) is connected with the diesel engine through the first input joint (3) and the first high-elastic coupling (2), the rear end of the output shaft (31) is connected with the propeller through the output joint (33), and the rear end of the second input shaft (21) is connected with the motor through the second input joint (20) and the second high-elastic coupling (19).

8. An oil-electric dual propulsion marine gear box as claimed in claim 7, wherein, The first input shaft (4) and the first input joint (3) are connected through the hydraulic sleeve with the conical interference, the output shaft (31) and the output joint (33) are connected through the hydraulic sleeve with the conical interference, and the second input shaft (21) and the second input joint (20) are connected through the hydraulic sleeve with the conical interference.

9. An oil-electric dual propulsion marine gear box as claimed in claim 1, wherein, The first input shaft (4) and the output shaft (31) are vertically arranged at different centers, the first input shaft (4) is located above the output shaft (31), the reverse shaft (11) is located on one side of the center line of the first input shaft (4) and the output shaft (31), and the second input shaft (21) is located above the output shaft (31).

10. An oil-electric dual propulsion marine gear case as claimed in claim 1, wherein, The box body comprises an upper box body (35), a middle box body (36) and a lower box body (37), the upper box body (35) and the middle box body (36) are horizontally split along the center line of the second input shaft (21), and the middle box body (36) and the lower box body (37) are obliquely split along the center lines of the input shaft (4) and the reverse shaft (11).

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