Semi-closed carbon dioxide gear speed-increasing centrifugal compressor structure
By combining a semi-enclosed design with dry gas seals and labyrinth seals, the problem of high-pressure gas leakage in carbon dioxide compressors has been solved, resulting in a compact, low-maintenance, and highly reliable carbon dioxide compressor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-27
- Publication Date
- 2026-04-10
AI Technical Summary
Existing carbon dioxide compressors suffer from reduced lubricating oil viscosity and deteriorated lubrication performance due to high-pressure gas leakage, resulting in gearbox deformation and affecting precision gear transmission. Furthermore, their open structure is large in size, heavy in weight, and not compact.
It adopts a semi-enclosed design, including a power component, a gear speed-increasing component, and a compression component. It uses a combination of dry gas seals and labyrinth seals to prevent high-pressure carbon dioxide gas leakage. Combined with a lubrication component to provide lubricating oil, it achieves isolation of the sealing components.
It achieves a compact structure, low maintenance cost, high reliability, excellent lubrication performance, small overall size and light weight, thus improving operational reliability and lifespan.
Smart Images
Figure CN121828211A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to a semi-closed carbon dioxide gear speed-increasing centrifugal compressor structure. BACKGROUND
[0002] As a natural working medium, carbon dioxide is increasingly important in the context of eliminating high-GWP synthetic refrigerants. Carbon dioxide, with its excellent environmental performance, excellent thermophysical properties, high safety and chemical stability, has given rise to a series of carbon dioxide refrigerant compressors and has been widely used. However, carbon dioxide generates extremely high pressure during operation, and the high-pressure gas continuously leaks into the gear box. These gases dissolve in the lubricating oil in the low-temperature environment of the gear box, causing the viscosity of the lubricating oil to decrease, the lubricating performance to deteriorate, and foaming, which seriously affects the service life of the gear and bearing. At the same time, the gear box deforms under high pressure, which seriously affects the precise transmission of the gear. This makes the compressor basically designed as an open structure, that is, the motor and other compression components of the compressor are not in the same housing, and the power is transmitted through a shaft coupling. However, the open structure compressor has a large overall size, a heavy weight, and an uncompact structure. SUMMARY
[0003] The application improves the prior art, that is, the technical problem to be solved by the application is to provide a semi-closed carbon dioxide gear speed-increasing centrifugal compressor structure.
[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: a semi-closed carbon dioxide gear speed-increasing centrifugal compressor structure, comprising, from back to front, a power assembly, a gear speed-increasing assembly and a compression assembly, the gear speed-increasing assembly comprising a gear box and a gear transmission member arranged in the gear box; the power output end of the power assembly is connected to the input end of the gear transmission member after passing through the gear box, and a first dry gas seal is arranged between the power output end of the power assembly and the gear box; the compression assembly comprises a volute and an impeller arranged in the volute, the impeller is connected to the output end of the gear transmission member, and a second dry gas seal is arranged between the output end of the gear transmission member and the volute.
[0005] Further, the gear transmission member comprises a driving gear connected to the power output end of the power assembly, a primary gear shaft and a secondary gear shaft distributed on the left and right sides of the driving gear, and the toothed shaft sections on the primary gear shaft and the toothed shaft sections on the secondary gear shaft are respectively engaged with the driving gear, and the front ends of the primary gear shaft and the secondary gear shaft protrude out of the gear box and serve as the output end of the gear transmission member.
[0006] Further, the volute comprises a first-stage volute and a second-stage volute corresponding to positions of the first-stage gear shaft and the second-stage gear shaft respectively, the first-stage volute is internally provided with a first-stage impeller connected with the first-stage gear shaft, and the second-stage volute is internally provided with a second-stage impeller connected with the second-stage gear shaft, a second dry gas seal A is arranged between the first-stage gear shaft and the first-stage volute, and a second dry gas seal B is arranged between the second-stage gear shaft and the second-stage volute.
[0007] Further, the front end of the gear box is open and is provided with a cover plate, the first-stage gear shaft and the second-stage gear shaft pass through the cover plate, a first labyrinth seal is arranged between the first-stage gear shaft and the cover plate, and a second labyrinth seal is arranged between the second-stage gear shaft and the cover plate.
[0008] Further, a first sliding bearing A is arranged between the rear end of the first-stage gear shaft and the gear box, and a first sliding bearing B matched with the first-stage gear shaft is arranged at the rear end of the first labyrinth seal; a second sliding bearing A is arranged between the rear end of the second-stage gear shaft and the gear box, and a second sliding bearing B matched with the second-stage gear shaft is arranged at the rear end of the second labyrinth seal.
[0009] Further, the power assembly comprises a motor rotor shaft and a motor stator arranged outside the motor rotor shaft, the front end of the motor rotor shaft extends into the gear box and is connected with the driving gear, and the first dry gas seal is arranged between the motor rotor shaft and the gear box.
[0010] Further, a third sliding bearing is further arranged between the motor rotor shaft and the gear box, and the third sliding bearing is located at the front side of the first dry gas seal.
[0011] Further, the lubricating assembly connected with the gear box is further arranged.
[0012] Further, the lubricating assembly comprises an oil pump, an oil cooler and an oil filter, the input end and the output end of the oil pump are connected with an oil tank and the gear box respectively, the oil cooler and the oil filter are arranged between the output end of the oil pump and the gear box and are sequentially arranged along the conveying direction of the lubricating oil.
[0013] Further, the power assembly further comprises a motor shell, the front end of the motor shell is connected with the rear end of the gear box, and the motor rotor shaft and the motor stator are both mounted in the motor shell.
[0014] Compared with the prior art, the present application has the following effects: the present application adopts a semi-closed design, has a compact structure, no coupling, low maintenance cost and high reliability; the dry gas sealing mode can reliably block the leakage of high-pressure carbon dioxide gas to the gear box. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1is a schematic view of a front view cross-sectional structure of an embodiment of the present application; Figure 2 is Figure 1 a schematic view of a partial structure in Figure 3 is a schematic view of a three-dimensional structure of an embodiment of the present application; in the figure: 1 - power assembly; 101 - motor stator; 102 - motor rotor shaft; 2 - gear box; 3 - first sliding bearing B; 4 - first sliding bearing A; 5 - cover plate; 6 - first volute; 7 - first labyrinth seal; 8 - second dry gas seal A; 9 - first stage impeller; 10 - first stage gear shaft; 11 - driving gear; 12 - second stage impeller; 13 - second stage gear shaft; 14 - second stage volute; 15 - second dry gas seal B; 16 - second labyrinth seal; 17 - second sliding bearing A; 18 - second sliding bearing B; 19 - third sliding bearing; 20 - first dry gas seal; 21 - oil pump; 22 - oil cooler; 23 - oil filter; 24 - motor casing. DETAILED DESCRIPTION
[0016] The present application will be further described below in conjunction with the drawings and specific embodiments.
[0017] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0018] As Figures 1 to 3As shown, the semi-closed carbon dioxide gear speed-increasing centrifugal compressor structure of the present application comprises, from back to front, a power assembly 1, a gear speed-increasing assembly and a compression assembly which are sequentially arranged and connected together. The main function of the power assembly is to provide power source for the rotating parts of the compressor. The gear speed-increasing assembly is used for speed-increasing, and comprises a gear box 2 and a gear transmission part arranged in the gear box 2. The power output end of the power assembly is connected with the input end of the gear transmission part after passing through the gear box 2, so as to realize power transmission. The first dry gas seal 20 is arranged between the power output end of the power assembly and the gear box 2. The main function of the compression assembly is to compress the low-temperature and low-pressure carbon dioxide gas into high-temperature and high-pressure carbon dioxide gas. The compression assembly comprises a volute installed on the gear box 2 and an impeller arranged in the volute. The impeller is connected with the output end of the gear transmission part, and the second dry gas seal is arranged between the output end of the gear transmission part and the volute. The dry gas sealing mode can reliably block the leakage of high-pressure carbon dioxide gas to the gear box.
[0019] In the embodiment, the gear transmission part comprises a driving gear 11 connected with the power output end of the power assembly, a first-stage gear shaft 10 and a second-stage gear shaft 13 which are distributed on the left and right sides of the driving gear 11 in the horizontal plane. The first-stage gear shaft 10 and the second-stage gear shaft 13 are both machined with teeth which are engaged with the driving gear, i.e. the toothed shaft sections on the first-stage gear shaft 10 and the second-stage gear shaft 13 are engaged with the driving gear 11, respectively. In this way, the low-speed rotation of the driving gear is changed into the high-speed rotation of the first-stage gear shaft and the second-stage gear shaft through a certain gear ratio. The front ends of the first-stage gear shaft 10 and the second-stage gear shaft 13 extend out of the gear box 2 and serve as the output end of the gear transmission part.
[0020] In the embodiment, the volute comprises a first-stage volute 6 and a second-stage volute 14 which correspond to the positions of the first-stage gear shaft 10 and the second-stage gear shaft 10, respectively. The first-stage volute 6 is provided with a first-stage impeller 9 connected with the first-stage gear shaft 10, and the second-stage volute 14 is provided with a second-stage impeller 12 connected with the second-stage gear shaft 13. The low-temperature and low-pressure carbon dioxide gas is sequentially compressed by the first-stage impeller 9 and the second-stage impeller 12. Further, the second dry gas seal A8 is arranged between the first-stage gear shaft 10 and the first-stage volute 6, and the second dry gas seal B15 is arranged between the second-stage gear shaft 13 and the second-stage volute 14. The second dry gas seals A and B can reliably block the leakage of high-pressure carbon dioxide gas to the gear box.
[0021] In the embodiment, the front end of the gear box 2 is open and provided with a cover plate 5, the first gear shaft 10 and the second gear shaft 13 both pass through the cover plate 5, the first gear shaft 10 is provided with a first labyrinth seal 7 behind the second dry gas seal A, and the two cooperate to improve the sealing effect; the second gear shaft 13 is provided with a second labyrinth seal 16 behind the second dry gas seal B, and the two cooperate to improve the sealing effect.
[0022] The sealing assembly is composed of the first dry gas seal, the second dry gas seal A, the second dry gas seal B, the first labyrinth seal and the second labyrinth seal, and the power assembly, the gear speed-up assembly and the compression assembly are separated by the sealing assembly to prevent the high-temperature and high-pressure carbon dioxide gas in the compression assembly from leaking to the gear speed-up assembly.
[0023] In the embodiment, the first volute 6 and the second volute 14 are both mounted on the cover plate 5.
[0024] In the embodiment, the rear end of the first gear shaft 10 is provided with a first sliding bearing A4 between the first gear shaft 10 and the gear box 2, and the rear end of the first labyrinth seal 7 is provided with a first sliding bearing B3 matched with the first gear shaft 10, the first sliding bearing B and the first sliding bearing A are distributed on the front and rear sides of the toothed shaft section of the first gear shaft; the rear end of the second gear shaft 13 is provided with a second sliding bearing A17 between the second gear shaft 13 and the gear box 2, and the rear end of the second labyrinth seal 16 is provided with a second sliding bearing B18 matched with the second gear shaft 13, the second sliding bearing B and the second sliding bearing A are distributed on the front and rear sides of the toothed shaft section of the second gear shaft.
[0025] In the embodiment, the power assembly 1 includes a motor rotor shaft 102 and a motor stator 101 arranged outside the motor rotor shaft 102, the front end of the motor rotor shaft 102 extends into the gear box 2 and is connected with the driving gear 11; the first dry gas seal 20 is arranged between the motor rotor shaft 102 and the gear box 2. Further, the power assembly further includes a motor shell 24, the front end of the motor shell 24 is connected with the rear end of the gear box 2, and the motor rotor shaft 102 and the motor stator 101 are both mounted in the motor shell 24.
[0026] In the embodiment, the motor rotor shaft 102 and the gear box 2 are further provided with a third sliding bearing 19, and the third sliding bearing is located on the front side of the first dry gas seal.
[0027] In this embodiment, a lubricating assembly connected with the gear box 2 is further included, which is used for providing lubricating oil for the gears, gear shafts and sliding bearings, and plays a role of lubrication and heat dissipation. Specifically, the lubricating assembly includes an oil pump 21, an oil cooler 22 and an oil filter 23, the input end and the output end of the oil pump 21 are connected with an oil tank and the gear box 2 respectively, the oil cooler 22 and the oil filter 23 are arranged between the output end of the oil pump 21 and the gear box 2, and are sequentially arranged along the conveying direction of the lubricating oil, as shown in Figure 3 .
[0028] It should be noted that the dry gas seal and the labyrinth seal are both mature products, the dry gas seal, namely "dry running gas seal", is a new type of shaft end seal using the slotted sealing technology for gas sealing, and belongs to non-contact sealing; the labyrinth seal refers to a seal in which there are many small and tortuous chambers between the rotating part and the fixed part to reduce leakage. The installation and working principle of the dry gas seal and the labyrinth seal are both known technologies in the art, and will not be repeated here.
[0029] The advantages of the present application are: (1) The semi-closed design is adopted, the structure is compact, there is no shaft coupling, the maintenance cost is low, and the reliability is high; (2) The isolated design is formed through the dry gas seal and the labyrinth seal, the lubricating performance of the lubricating oil is ensured, and thus the operation reliability and the service life of the whole machine are improved; (3) The structure is compact, the size of the whole machine is small, and the weight is low.
[0030] If the present application discloses or involves parts or structural members fixedly connected with each other, the fixed connection can be understood as: detachable fixed connection (for example, connected by bolts or screws), or non-detachable fixed connection (for example, riveting, welding), of course, the fixed connection can also be replaced by an integral structure (for example, manufactured by integral forming process, except for obvious cases that integral forming process cannot be used).
[0031] In addition, the terms used to represent the position relationship or shape in any of the technical solutions disclosed in the present application include approximate, similar or close states or shapes, unless otherwise stated.
[0032] Any component provided by the present application can be assembled from multiple individual components, or can be a single component manufactured by integral forming process.
[0033] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it; although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones without departing from the spirit of the technical solutions of the present application, and all of them should be covered in the technical solution range claimed by the present application.
Claims
1. A semi-hermetic carbon dioxide gear-driven centrifugal compressor structure, characterized in that: The device includes a power assembly, a gear speed-increasing assembly, and a compression assembly arranged sequentially from back to front. The gear speed-increasing assembly includes a gearbox and a gear transmission component disposed within the gearbox. The power output end of the power assembly passes through the gearbox and connects to the input end of the gear transmission component. A first dry gas seal is provided between the power output end of the power assembly and the gearbox. The compression assembly includes a volute and an impeller disposed within the volute. The impeller is connected to the output end of the gear transmission component. A second dry gas seal is provided between the output end of the gear transmission component and the volute.
2. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 1, characterized in that: The gear transmission component includes a drive gear connected to the power output end of the power assembly, a first-stage gear shaft and a second-stage gear shaft distributed on the left and right sides of the drive gear. The toothed shaft sections on the first-stage gear shaft and the second-stage gear shaft mesh with the drive gear, respectively. The front ends of the first-stage gear shaft and the second-stage gear shaft extend out of the gearbox and serve as the output ends of the gear transmission component.
3. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 2, characterized in that: The volute includes a primary volute and a secondary volute, which are respectively positioned corresponding to the primary gear shaft and the secondary gear shaft. A primary impeller connected to the primary gear shaft is disposed inside the primary volute, and a secondary impeller connected to the secondary gear shaft is disposed inside the secondary volute. A second dry gas seal A is disposed between the primary gear shaft and the primary volute, and a second dry gas seal B is disposed between the secondary gear shaft and the secondary volute.
4. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 2, characterized in that: The front end of the gearbox is open and has a cover plate. The first-stage gear shaft and the second-stage gear shaft both pass through the cover plate. A first labyrinth seal is provided between the first-stage gear shaft and the cover plate, and a second labyrinth seal is provided between the second-stage gear shaft and the cover plate.
5. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 4, characterized in that: A first sliding bearing A is provided between the rear end of the first-stage gear shaft and the gearbox, and a first sliding bearing B that mates with the first-stage gear shaft is provided at the rear end of the first labyrinth seal; a second sliding bearing A is provided between the rear end of the second-stage gear shaft and the gearbox, and a second sliding bearing B that mates with the second-stage gear shaft is provided at the rear end of the second labyrinth seal.
6. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 2, characterized in that: The power assembly includes a motor rotor shaft and a motor stator disposed outside the motor rotor shaft. The front end of the motor rotor shaft extends into the gearbox and is connected to the drive gear. The first dry gas seal is disposed between the motor rotor shaft and the gearbox.
7. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 6, characterized in that: A third sliding bearing is also provided between the motor rotor shaft and the gearbox, and the third sliding bearing is located on the front side of the first dry gas seal.
8. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 1, characterized in that: It also includes a lubrication assembly connected to the gearbox.
9. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 8, characterized in that: The lubrication assembly includes an oil pump, an oil cooler, and an oil filter. The input and output ends of the oil pump are connected to the oil tank and the gearbox, respectively. The oil cooler and the oil filter are arranged between the output end of the oil pump and the gearbox, and are arranged sequentially along the direction of lubricant delivery.
10. The semi-hermetic carbon dioxide gear-driven centrifugal compressor structure according to claim 6, characterized in that: The power assembly also includes a motor housing, the front end of which is connected to the rear end of the gearbox, and the motor rotor shaft and motor stator are both installed inside the motor housing.