Gearbox for screw compressor for LNG (Liquefied Natural Gas) ship
By designing the screw pump and the first oil injection ring in the gear box of the LNG marine screw compressor, the problem of lubricating oil oil supply instability caused by frequent uncontrollable sway inertia is solved, and the stable control of bearing vibration, temperature rise and temperature is achieved to ensure the normal operation of the gear box in a swaying environment.
Patent Information
- Application Number
- CN202411854984.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-04-11
AI Technical Summary
Frequent uncontrollable swaying inertia affects the lubricating fluid, resulting in instability of lubricating oil supply, leading to problems such as large vibration, rapid temperature rise and high temperature. In severe cases, lubrication failure may lead to direct burnout of the bearing.
A gear box for LNG marine screw compressors is designed to shorten the inlet and return oil pipelines through screw pumps to reduce losses along the way. Combined with the pressure reduction and flow restriction effect of the first oil injection ring, it ensures the stability of the lubricating oil pressure and reduces the impact of sway inertia on the lubricating fluid.
It effectively ensures the stability of lubricating oil supply, avoids the problems of large vibration, fast temperature rise and high temperature, and ensures that the gearbox operates normally in a slanting environment.
Smart Images
Figure CN119802196A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of gear boxes, and in particular to a gear box for a screw compressor used in LNG ships. Background Art
[0002] Currently, river-to-sea 14,000 cubic meter liquefied natural gas (LNG) bunkering transport ships need to be equipped with gearboxes. In the power system of LNG ships, gearboxes are usually used to convert the high-torque, low-speed power generated by the engine into low-torque, high-speed power to drive propellers or other propulsion devices. This conversion is crucial to ensure that the ship can sail at an appropriate speed.
[0003] In the prior art, the gearbox operates on an LNG ship, where the cabin is an explosive environment. During shipping, there are large inclination angles and swing amplitudes, with the maximum lateral inclination angle of 22.5° and the maximum longitudinal inclination angle of 7.5°. The resulting hull accelerations are: 0.97g lateral, 0.17g longitudinal, and 1.35g vertical. Therefore, the frequent and uncontrollable swing inertia has a blocking effect on the lubricating fluid, which will cause instability in the lubricating oil supply, resulting in large bearing vibration, rapid temperature rise, and high temperature. In severe cases, it may cause lubrication failure and directly burn the bearing. Summary of the invention
[0004] The purpose of the present invention is to provide a gearbox for LNG ship screw compressor to solve the problem that the frequent uncontrollable swing inertia in the prior art has a blocking effect on the lubricating fluid, which may cause instability in the lubricating oil supply, resulting in large bearing vibration, rapid temperature rise and high temperature. In severe cases, it may cause lubrication failure and directly burn the bearing.
[0005] To achieve the above-mentioned object, the present invention provides a gearbox for a screw compressor for an LNG ship, comprising a housing, an input shaft component, a primary output shaft component, a secondary output shaft component, a primary idler shaft component and a secondary idler shaft component, wherein the input shaft component is arranged inside the housing, the primary output shaft component and the secondary output shaft component are symmetrically arranged on the housing, the primary idler shaft component and the secondary idler shaft component are symmetrically arranged inside the housing and connected to the input shaft component;
[0006] The input shaft component includes an input shaft, a first bearing, a first adjustment pad, a first oil injection ring, a pump seat, an adapter plate, a coupling and a screw pump. The input shaft is arranged inside the housing, the first bearing is arranged at one end of the input shaft, the first adjustment pad is arranged at one side of the first bearing, the first oil injection ring is arranged on the first adjustment pad, the pump seat is arranged above the housing, the adapter plate is arranged at the other end of the input shaft, and the two ends of the coupling are respectively connected to the adapter plate and the screw pump.
[0007] Wherein, the input shaft component also includes a first oil slinger, a first seal, a spring, a first distance ring and a first gear, the first distance ring is arranged on one side of the first bearing, the first adjustment pad is sleeved on the outside of the first distance ring, the spring is arranged on the inside of the first adjustment pad, the first oil slinger is sleeved on one end of the input shaft and is located on one side of the first distance ring, the first seal is sleeved on the outside of the first oil slinger, the first seal is located below the housing, and the first gear is sleeved on the outside of the input shaft and is located inside the housing.
[0008] The first-stage output shaft component and the second-stage output shaft component have the same structure, and both include a high-speed shaft, a second oil slinger, a second seal, a second adjustment pad, a third adjustment pad, a second distance ring, a third distance ring, a second oil injection ring, a third oil injection ring, a second bearing and a third bearing. The high-speed shaft is arranged inside the housing, the second oil slinger is sleeved on one end of the high-speed shaft, the second seal is sleeved on the outside of the second oil slinger and is fixedly connected to the top of the housing, the second distance ring is sleeved on the outside of the high-speed shaft and is located below the second oil slinger, the second adjustment pad is sleeved on the outside of the second distance ring and is located inside the housing, the second oil injection ring is arranged on the second adjustment pad, the second bearing is sleeved on the outside of the high-speed shaft and is located below the second distance ring, the third bearing is sleeved on the other end of the high-speed shaft, the third adjustment pad is sleeved on the outside of the third bearing, the third distance ring is sleeved on the outside of the high-speed shaft and is located above the third bearing, and the third oil injection ring is arranged on the third adjustment pad.
[0009] Wherein, the primary output shaft component and the secondary output shaft component further include a first end cover and a baffle, the first end cover is arranged below the box body, and the baffle is arranged at the other end of the high-speed shaft and is located below the third bearing.
[0010] Among them, the first-stage idler shaft component and the second-stage idler shaft component have the same structure, both including an idler shaft, a second end cover, a fourth adjustment pad, a fourth bearing and a second gear, the idler shaft is arranged inside the housing and is located between the high-speed shaft and the input shaft, the fourth bearing is sleeved on the outside of the idler shaft, the fourth adjustment pad is arranged on the outside of the fourth bearing, the second gear is sleeved on the outside of the idler shaft, the idler shaft and the high-speed shaft are connected through the second gear, the first gear and the second gear are meshed with each other, and the second end cover is arranged below the housing.
[0011] The screw pump is designed with an oil suction port of -0.6MPa and an oil outlet of 1.1MPa to ensure that the lubricating oil pressure output by the gear box is stable at >0.4MPa under continuous deflection.
[0012] The present invention discloses a gearbox for a screw compressor for an LNG ship, which is connected to a driving device through the input shaft component, and then driven to operate the first-level output shaft component and the second-level output shaft component through the connection between the first-level idler shaft component and the second-level idler shaft component, so as to output power and drive a propeller; the input shaft is connected to an external driving device, the first oil injection ring can spray out the internal lubricating oil, and play a role of reducing pressure and limiting flow, the first oil injection ring is close to the first bearing, and a small gap is designed with the shaft diameter to form a first seal, which can prevent high-pressure oil from directly impacting the seal and reduce the flow of lubricating oil in the sealing direction, the pump seat supports the screw pump, and when the input shaft rotates, the screw pump is driven to operate through the connection between the adapter plate and the coupling, and through the above-mentioned structural setting, the screw pump can greatly shorten the inlet and return oil pipelines, reduce the loss along the way, cooperate with the effect of reducing pressure and limiting flow, effectively reduce the blocking effect of swing inertia on the lubricating fluid, ensure the stability of lubricating oil supply, thereby avoiding the problems of large bearing vibration, fast temperature rise and high temperature. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.
[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.
[0015] Figure 2 The present invention Figure 1 A magnified view of the local structure at A.
[0016] Figure 3 The present invention Figure 1 Enlarged view of the local structure at point B.
[0017] Figure 4 The present invention Figure 1 Enlarged view of the local structure at location C.
[0018] Figure 5 The present invention Figure 1 Enlarged view of the local structure at D.
[0019] 1-housing, 2-input shaft, 3-first bearing, 4-first adjusting pad, 5-first oil injection ring, 6-pump seat, 7-adapter plate, 8-coupling, 9-screw pump, 10-first oil slinger ring, 11-first seal, 12-spring, 13-first distance ring, 14-first gear, 15-high-speed shaft, 16-second oil slinger ring, 17-second seal, 18-second adjusting pad, 19-third adjusting pad, 20-second distance ring, 21-third distance ring, 22-second oil injection ring, 23-third oil injection ring, 24-second bearing, 25-third bearing, 26-first end cover, 27-baffle, 28-idle shaft, 29-second end cover, 30-fourth adjusting pad, 31-fourth bearing, 32-second gear. DETAILED DESCRIPTION
[0020] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.
[0021] See also Figures 1 to 5 The present invention provides a gearbox for an LNG marine screw compressor, comprising a housing 1, an input shaft 2 component, a primary output shaft component, a secondary output shaft component, a primary idler shaft 28 component and a secondary idler shaft 28 component, wherein the input shaft 2 component comprises an input shaft 2, a first bearing 3, a first adjustment pad 4, a first oil injection ring 5, a pump seat 6, an adapter plate 7, a coupling 8 and a screw pump 9, wherein the input shaft 2 component further comprises a first oil slinger 10, a first seal 11, a spring 12, a first distance ring 13 and a first gear 14, wherein the primary output shaft component and the secondary output shaft component The first-stage output shaft component and the second-stage output shaft component have the same structure, both including a high-speed shaft 15, a second oil slinger 16, a second seal 17, a second adjustment pad 18, a third adjustment pad 19, a second distance ring 20, a third distance ring 21, a second oil injection ring 22, a third oil injection ring 23, a second bearing 24 and a third bearing 25. The first-stage output shaft component and the second-stage output shaft component also include a first end cover 26 and a baffle 27. The first-stage idler shaft 28 component and the second-stage idler shaft 28 component have the same structure, both including an idler shaft 28, a second end cover 29, a fourth adjustment pad 30, a fourth bearing 31 and a second gear 32.
[0022] Among them, the input shaft 2 component is arranged inside the housing 1, the first-level output shaft component and the second-level output shaft component are symmetrically arranged on the housing 1, the first-level idler shaft 28 component and the second-level idler shaft 28 component are symmetrically arranged inside the housing 1 and connected with the input shaft 2 component, the input shaft 2 is arranged inside the housing 1, the first bearing 3 is arranged at one end of the input shaft 2, the first adjustment pad 4 is arranged on one side of the first bearing 3, the first oil injection ring 5 is arranged on the first adjustment pad 4, the pump seat 6 is arranged above the housing 1, the adapter plate 7 is arranged at the other end of the input shaft 2, and the two ends of the coupling 8 are respectively connected to the adapter plate 7 and the screw pump 9. The input shaft 2 is connected to the driving device, and then through the connection between the first-level idler shaft 28 and the second-level idler shaft 28, the first-level output shaft and the second-level output shaft are driven to operate, output power, and then drive the propeller; the input shaft 2 is connected to the external driving device, and the first oil spray ring 5 can spray the internal lubricating oil to take away the heat, thereby playing a cooling role. At the same time, the lubricating oil that can be sprayed can also play a cleaning role, flushing away metal debris and dust, and keeping the inside of the gear box clean. The first oil spray ring 5 is close to the first bearing 3 and is designed with a small gap with the shaft diameter to form a first seal, which can prevent high-pressure oil from directly impacting the seal and reduce the flow of lubricating oil in the sealing direction, playing a role of reducing pressure and limiting flow. The pump seat 6 supports the screw pump 9. When the input shaft 2 rotates, the screw pump 9 is driven to operate through the connection between the adapter plate 7 and the coupling 8.
[0023] Secondly, the first distance ring 13 is arranged on one side of the first bearing 3, the first adjustment pad 4 is sleeved on the outside of the first distance ring 13, the spring 12 is arranged inside the first adjustment pad 4, the first oil slinger 10 is sleeved on one end of the input shaft 2 and is located on one side of the first distance ring 13, the first seal 11 is sleeved on the outside of the first oil slinger 10, the first seal 11 is located below the housing 1, and the first gear 14 is sleeved on the outside of the input shaft 2 and is located inside the housing 1. The first distance ring 13 can be used to fix the axial position, increase structural stability, and adjust the gear clearance. The first adjustment pad 4 can compensate for the uneven contact surface. In conjunction with the spring 12, the clearance size can be adjusted to have a buffering and shock-absorbing effect and adapt to different working environments. The first oil-slinging ring 10 can prevent the leakage of lubricating oil and prevent external impurities from entering. When the first bearing 3 rotates, the first oil-slinging ring 10 can throw out the lubricating oil attached to the input shaft 2 or the first bearing 3 to prevent it from entering the high-speed rotating part, thereby reducing the loss and waste of lubricating oil. When the input shaft 2 rotates, it drives the first gear 14 to rotate and mesh with the second gear 32, thereby driving the idler shaft 28 and the high-speed shaft 15 to rotate.
[0024] At the same time, the high-speed shaft 15 is arranged inside the housing 1, the second oil slinger 16 is sleeved on one end of the high-speed shaft 15, the second seal 17 is sleeved on the outside of the second oil slinger 16 and is fixedly connected to the top of the housing 1, the second distance ring 20 is sleeved on the outside of the high-speed shaft 15 and is located below the second oil slinger 16, the second adjustment pad 18 is sleeved on the outside of the second distance ring 20 and is located inside the housing 1, the second oil injection ring 22 is arranged on the second adjustment pad 18, the second bearing 24 is sleeved on the outside of the high-speed shaft 15 and is located below the second distance ring 20, the third bearing 25 is sleeved on the other end of the high-speed shaft 15, the third adjustment pad 19 is sleeved on the outside of the third bearing 25, the third distance ring 21 is sleeved on the outside of the high-speed shaft 15 and is located above the third bearing 25, and the third oil injection ring 23 is arranged on the third adjustment pad 19. The idler shaft 28 rotates to drive the high-speed shaft 15 to rotate, and then the high-speed shaft 15 is connected to an external propeller. The second oil slinger 16 can throw out the lubricating oil attached to the high-speed shaft 15 to prevent it from entering the high-speed rotating part, thereby reducing the loss and waste of lubricating oil. The second seal 17 seals the connection between the high-speed shaft 15 and the casing 1 to prevent lubricating oil leakage. The functions of the second adjustment pad 18 and the third adjustment pad 19 are the same as those of the first adjustment pad 4. The functions of the second distance ring 20 and the third distance ring 21 are the same as those of the first distance ring 13. The functions of the second oil injection ring 22 and the third oil injection ring 23 are the same as those of the first oil injection ring 5. The second bearing 24 and the third bearing 25 are used to fix the high-speed shaft 15 to reduce friction and wear.
[0025] In addition, the first end cover 26 is arranged below the housing 1, and the baffle 27 is arranged at the other end of the high-speed shaft 15 and below the third bearing 25. An oil return groove is provided at a suitable position on the third adjustment pad 19, and the baffle 27 is welded on the outside of this position to form a second seal, so that most of the lubricating oil decelerated by the first layer of sealing directly flows back to the bottom of the housing 1; at the same time, an oil return hole of the housing 1 is provided between the crescent-shaped baffle 27 and the first end cover 26, and is connected to the oil return of the first end cover 26. The first end cover 26 adopts multi-layer non-contact oil throwing for sealing, and an oil return hole is provided in each layer to form a third seal.
[0026] Then, the idler shaft 28 is arranged inside the housing 1 and between the high-speed shaft 15 and the input shaft 2, the fourth bearing 31 is sleeved outside the idler shaft 28, the fourth adjustment pad 30 is arranged outside the fourth bearing 31, the second gear 32 is sleeved outside the idler shaft 28, the idler shaft 28 and the high-speed shaft 15 are connected through the second gear 32, the first gear 14 and the second gear 32 are meshed with each other, and the second end cover 29 is arranged below the housing 1. The input shaft 2 rotates, and the idler shaft 28 is driven through the first gear 14 and the enemy gear, thereby driving the high-speed shaft 15, the second end cover 29 has the same function as the first end cover 26, the fourth adjustment pad 30 has the same function as the first adjustment pad 4, and the fourth bearing 31 has the same function as the first bearing 3.
[0027] Finally, the screw pump 9 is designed with an oil suction port of -0.6MPa and an oil outlet of 1.1MPa to ensure that the lubricating oil pressure output by the gear box is stable at >0.4MPa under continuous deflection.
[0028] When using a gearbox for an LNG ship screw compressor of the present embodiment, the input shaft 2 is connected to the driving device, and then the first-level idler shaft 28 component and the second-level idler shaft 28 component are connected to drive the first-level output shaft component and the second-level output shaft component to operate, output power, and then drive the propeller; the first oil injection ring 5 can spray the internal lubricating oil, the first oil injection ring 5 is close to the first bearing 3, and is designed with a small gap with the shaft diameter to form a first seal, which can prevent the high-pressure oil from directly impacting the seal and reduce the flow of lubricating oil in the sealing direction, thereby playing the role of reducing pressure and limiting flow. The pump seat 6 supports the screw pump 9. When the input shaft 2 rotates, the screw pump 9 is driven to operate through the connection between the adapter plate 7 and the coupling 8. The sealing effect is effectively guaranteed through the pressure reduction and flow limiting, the backflow of the baffle 27, and the third seal of the end cover. Through the above-mentioned structural arrangement, the screw pump 9 can greatly shorten the inlet and return oil pipelines, reduce the loss along the way, and cooperate with the effect of pressure reduction and flow limiting to effectively reduce the blocking effect of the swing inertia on the lubricating fluid, thereby ensuring the stability of the lubricating oil supply, thereby avoiding the problems of large bearing vibration, rapid temperature rise and high temperature.
[0029] What is disclosed above is only one or more preferred embodiments of the present application, and cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.
Claims
1. A gearbox for a screw compressor for LNG ships, characterized in that: It comprises a box body, an input shaft component, a primary output shaft component, a secondary output shaft component, a primary idler shaft component and a secondary idler shaft component, wherein the input shaft component is arranged inside the box body, the primary output shaft component and the secondary output shaft component are symmetrically arranged on the box body, the primary idler shaft component and the secondary idler shaft component are symmetrically arranged inside the box body and connected to the input shaft component; The input shaft component includes an input shaft, a first bearing, a first adjustment pad, a first oil injection ring, a pump seat, an adapter plate, a coupling and a screw pump. The input shaft is arranged inside the housing, the first bearing is arranged at one end of the input shaft, the first adjustment pad is arranged at one side of the first bearing, the first oil injection ring is arranged on the first adjustment pad, the pump seat is arranged above the housing, the adapter plate is arranged at the other end of the input shaft, and the two ends of the coupling are respectively connected to the adapter plate and the screw pump.
2. The gearbox for a screw compressor for an LNG ship according to claim 1, characterized in that: The input shaft component also includes a first oil slinger, a first seal, a spring, a first distance ring and a first gear. The first distance ring is arranged on one side of the first bearing, the first adjustment washer is sleeved on the outside of the first distance ring, the spring is arranged on the inside of the first adjustment washer, the first oil slinger is sleeved on one end of the input shaft and is located on one side of the first distance ring, the first seal is sleeved on the outside of the first oil slinger, the first seal is located below the housing, and the first gear is sleeved on the outside of the input shaft and is located inside the housing.
3. The gearbox for a screw compressor for an LNG ship according to claim 2, characterized in that: The primary output shaft component and the secondary output shaft component have the same structure, and both include a high-speed shaft, a second oil slinger, a second seal, a second adjustment pad, a third adjustment pad, a second distance ring, a third distance ring, a second oil injection ring, a third oil injection ring, a second bearing and a third bearing. The high-speed shaft is arranged inside the housing, the second oil slinger is sleeved on one end of the high-speed shaft, the second seal is sleeved on the outside of the second oil slinger and is fixedly connected to the top of the housing, the second distance ring is sleeved on the outside of the high-speed shaft and is located below the second oil slinger, the second adjustment pad is sleeved on the outside of the second distance ring and is located inside the housing, the second oil injection ring is arranged on the second adjustment pad, the second bearing is sleeved on the outside of the high-speed shaft and is located below the second distance ring, the third bearing is sleeved on the other end of the high-speed shaft, the third adjustment pad is sleeved on the outside of the third bearing, the third distance ring is sleeved on the outside of the high-speed shaft and is located above the third bearing, and the third oil injection ring is arranged on the third adjustment pad.
4. The gearbox for a screw compressor for an LNG ship according to claim 3, characterized in that: The primary output shaft component and the secondary output shaft component further include a first end cover and a baffle, wherein the first end cover is arranged below the housing, and the baffle is arranged at the other end of the high-speed shaft and is located below the third bearing.
5. The gearbox for a screw compressor for an LNG ship according to claim 4, characterized in that: The first-stage idler shaft component and the second-stage idler shaft component have the same structure, and both include an idler shaft, a second end cover, a fourth adjustment pad, a fourth bearing and a second gear. The idler shaft is arranged inside the housing and between the high-speed shaft and the input shaft. The fourth bearing is sleeved on the outside of the idler shaft. The fourth adjustment pad is arranged on the outside of the fourth bearing. The second gear is sleeved on the outside of the idler shaft. The idler shaft and the high-speed shaft are connected through the second gear. The first gear and the second gear are meshed with each other. The second end cover is arranged below the housing.
6. The gearbox for a screw compressor for an LNG ship according to claim 5, characterized in that: The screw pump is designed with an oil suction port of -0.6MPa and an oil outlet of 1.1MPa to ensure that the lubricating oil pressure output by the gear box is stable at >0.4MPa under continuous deflection.