A dual-head compressor

Abstract

This invention relates to the technical field of compressors, and more specifically, to a dual-head compressor, comprising two compressor bodies; an intermediate shell containing a single stator; each compressor body having a screw shaft extending into the intermediate shell, and a mating shell at one end of the compressor body; the screw shaft being connected to a rotor body via a bushing, and when the mating shell is connected to the end of the intermediate shell, the rotor body extends inward to fit the stator body; the bushing has a connecting end and an isolating end at its two ends, with the screw shaft extending inward to the connecting end and the end of the screw shaft recessed at the isolating end, the inner diameter of the isolating end being larger than that of the connecting end, and the rotor body being supported only by the connecting end. This invention offers the following advantages: the recessed end of the screw shaft at the isolating end shifts the center of gravity of the bushing towards the compressor body, effectively reducing the cantilever length of the rotor body, replacing the traditional dual-motor dual-main-machine axial redundant arrangement structure, effectively reducing the axial dimensions of the unit, reducing the equipment footprint, and lowering the spatial adaptation difficulty for transportation and on-site installation.

Description

Technical Field

[0001] This invention relates to the technical field of compressors, and more specifically, to a dual-head compressor. Background Technology

[0002] Screw compressors mainly consist of two core components: the compressor itself and the motor. The motor provides the drive power for the compressor's main unit. To achieve power transmission between the two drive shafts, couplings are commonly used in the industry. However, in gas compression applications, when high operating pressures are required, single-stage compression solutions have significant technical limitations: not only is the compression efficiency low, leading to excessively high energy costs and poor economic efficiency, but they also cannot even meet design pressure requirements in some high-pressure scenarios. Therefore, multi-stage compression technology must be employed.

[0003] The core principle of multi-stage compression is to start the gas from its initial intake state and gradually increase its pressure through multiple stages until the target working pressure is reached. Taking a common two-stage screw air compressor as an example, its specific compression process is as follows: Natural air first enters the first-stage compression chamber through an air filter. In the chamber, it mixes with a small amount of lubricating oil, completing the first compression and reaching the interstage pressure. The mixed gas after the first stage compression then enters the cooling channel, where it comes into full contact with a large amount of oil mist, achieving rapid cooling and preventing excessive temperature from affecting subsequent compression efficiency and equipment stability. The cooled compressed gas enters the second-stage rotor chamber, completing the second-stage compression process, and is finally compressed to the set exhaust pressure to meet the actual application requirements.

[0004] Based on the aforementioned high-pressure gas compression requirements, when adopting a two-stage compression scheme, traditional designs require two independent motors as the power source for the primary and secondary compressors, respectively. While this design can meet the power output requirements, it has significant drawbacks: the two motors and their corresponding compressors must be arranged sequentially along the axial direction, resulting in redundant axial dimensions and a lengthy structure for the entire unit. This not only significantly increases the equipment's footprint but also complicates spatial adaptation during transportation and installation.

[0005] To address the structural redundancy issues of dual-motor solutions, improved solutions have emerged in the industry that integrate two-stage compressors into a single motor drive. For example, Chinese patent CN105626530A discloses a water-lubricated, oil-free, medium-pressure, two-stage single-screw air compressor. Its technical solution involves using a single electric motor as the core power source. The screw shaft of the first-stage single-screw compressor is connected to the front shaft of the motor via a first-stage connecting sleeve, while the screw shaft of the second-stage single-screw compressor is connected to the rear shaft of the motor via a second-stage coupling. This single-motor, dual-output-shaft structure provides power for both stages of compression. However, this integrated solution is cumbersome to install and prone to damage to transmission components during long-term operation. Summary of the Invention

[0006] 1. The technical problem that the invention aims to solve The purpose of this invention is to optimize the connection method of the two-stage compressor and reduce the footprint of the equipment.

[0007] 2. Technical Solution To achieve the above objectives, the technical solution provided by the present invention is: a dual-head compressor, comprising... The compressor consists of two compressor bodies, one a single-screw compressor and the other a twin-screw compressor. The intermediate shell is open at both ends, and a single stator body is installed inside the intermediate shell; The compressor body has a screw shaft extending into the intermediate shell, and a docking shell is provided at the end of the compressor body. The docking shell and the end of the compressor body together seal the inner cavity of the intermediate shell. The screw shaft is connected to the rotor body via a bushing. When the mating shell is connected to the end of the intermediate shell, the rotor body extends and engages with the stator body to rotate. The rotor body drives the screw shaft to work with the internal structure of the compressor body to compress the gas. The bushing has a connecting end and an isolating end at its two ends. The screw shaft extends inward and connects to the connecting end, while the end of the screw shaft is recessed into the isolating end. The inner diameter of the isolating end is larger than that of the connecting end, which makes the center of gravity of the bushing closer to the compressor body. The end face of the screw shaft is located within the thickness range of the rotor body along the axial direction, and the rotor body is supported only by the connecting end.

[0008] The above technical solution, unlike a single rotor body, sets two rotor bodies within a single stator, each rotor body being individually connected to a screw shaft. During installation, the screw shafts on both sides can be individually connected, forming a separate integral structure. Compared to exposed coupling connections, this allows a single drive source to drive two compressor bodies. Simultaneously, the recessed and individually connected input power shaft enables a shorter layout. By retracting the screw shaft end to the isolation end and shifting the bushing's center of gravity towards the compressor body, the rotor cantilever length is effectively reduced. This replaces the traditional dual-motor, dual-host axial redundant arrangement structure, effectively reducing the unit's axial dimensions, decreasing the equipment's footprint, and simplifying the spatial adaptation for transportation and on-site installation.

[0009] Preferably, when the screw shaft carries the rotor body into the intermediate shell from one end, the mating shell simultaneously limits the axial and radial positions of the rotor body, so that there is a separation gap between the isolation ends of the two bushings, allowing the two rotor bodies to work independently.

[0010] Through the above technical solution, the docking shell simultaneously completes the axial and radial positioning of the rotor body during the assembly process, eliminating the need for additional positioning fixtures and limiting accessories. This effectively simplifies the overall assembly process and improves assembly efficiency and alignment accuracy. Simultaneously, relying on the limiting function of the docking shell, a stable separation interval is formed at the two end bushing isolation ends, achieving complete isolation of the two rotor body working areas inside the intermediate shell. This ensures that the two compression structures operate independently, guaranteeing that the single-screw and twin-screw compressor bodies can stably complete the corresponding stages of gas compression operations, effectively ensuring the operating efficiency and exhaust pressure accuracy of the two-stage compression.

[0011] Preferably, the docking shells are symmetrically arranged at both ends of the intermediate shell, and the two rotor bodies are symmetrically or asymmetrically arranged inside the intermediate shell to accommodate the same or different screw shafts.

[0012] Through the above technical solution, the symmetrical arrangement of the connecting shells at both ends of the intermediate shell ensures uniform stress distribution and a regular structure, effectively improving the overall structural rigidity of the equipment and avoiding problems such as shell deformation and loosening of connections during long-term operation, thus significantly extending the service life of the equipment. Simultaneously, the two rotor bodies inside the intermediate shell can be arranged symmetrically or asymmetrically according to actual working conditions, while a single stator body can adapt to screw shaft structures of different specifications and parameters, flexibly matching the different working conditions required by low-pressure primary compression and high-pressure secondary compression, and compatible with various compression combination modes with the same and different parameters. This effectively solves the shortcomings of traditional two-stage compressors with fixed structural parameters and poor adaptability to working conditions, greatly improving the equipment's versatility and scenario adaptability.

[0013] Preferably, a cooling channel is provided in the side wall of the intermediate shell, and a cooling medium is introduced into the cooling channel to remove the heat generated in the closed inner cavity of the intermediate shell. There is a transmission gap between the connecting end of the bushing and the mating shell, and the transmission gap is directly connected to the inner wall of the intermediate shell.

[0014] With the above technical solution, when the intermediate shell is directly connected to the two compressor bodies, the interior of the intermediate shell is sealed. At the same time, the heat generated by the operation of the two rotor bodies is even greater, requiring cooling. The cooling medium provides full-area heat dissipation and cooling to the inner cavity of the intermediate shell and the working areas of the rotor and stator bodies. Meanwhile, a transmission gap is reserved between the bushing connection end and the mating shell to connect to the inner wall of the intermediate shell, forming a dedicated directional heat dissipation channel. This can quickly dissipate the frictional heat and conduction heat generated by the operation of the screw shaft and bushing to the cooling area of ​​the intermediate shell, achieving rapid heat dissipation and preventing bushing overheating, jamming, and aging failure caused by local heat accumulation. This significantly improves the operational reliability of the transmission components and the service life of the entire machine.

[0015] Preferably, the screw shaft is connected to the bushing to form a heat conductor as a whole. The heat conductor is transferred through the isolation end with a smaller cross-sectional area to the connection end with a larger cross-sectional area, which is used to guide heat to the transfer gap.

[0016] Through the above technical solution, the differentiated structure with a small cross-sectional area at the isolation end of the bushing and a large cross-sectional area at the connection end not only shifts the center of gravity of the rotor body, but also forms a gradient heat conduction structure. The heat generated by the screw shaft and rotor body during operation can be quickly collected through the small cross-sectional area isolation end, and then directionally conducted to the large cross-sectional area connection end. Relying on the larger heat dissipation area of ​​the connection end and the adjacent transmission gap, the heat can be quickly diffused and dissipated. The problem of local high temperature and heat accumulation at the shaft connection can be efficiently solved without the need for additional heat dissipation accessories. This effectively reduces the negative impact of high temperature on transmission accuracy and component material performance, improves the overall heat dissipation system, and greatly enhances the stable operation capability of the equipment under long-term continuous high temperature conditions.

[0017] Preferably, the docking shell is provided with a step arranged circumferentially, the step is inserted axially to the end of the intermediate shell, the outer diameter side of the step is used to simultaneously position the radial position of the compressor body and the rotor body, and the inner diameter side of the step is used to seal the internal cavity of the intermediate shell.

[0018] The above technical solution utilizes the outer diameter side of the stepped section to simultaneously achieve radial positioning of the compressor body and rotor body, effectively limiting radial runout and offset of components during high-speed operation, and significantly improving the coaxiality of the entire assembly. Simultaneously, the inner diameter side of the stepped section achieves complete sealing of the internal cavity of the intermediate shell, facilitating heat transfer and dissipation.

[0019] Preferably, a bearing is provided on the side of the screw shaft near the connecting end, the rotor body and the screw shaft share the bearing, one side of the bearing contacts the lubricating oil located inside the compressor body, the rotor body and the stator body are rubber-coated, the inner cavity of the intermediate shell can be used to receive the lubricating oil leaking from inside the compressor body, and the intermediate shell is provided with an oil drain port.

[0020] Through the above technical solution, the rotor body and screw shaft share a single set of bearings, eliminating redundant bearing assemblies in traditional structures, effectively simplifying the overall transmission assembly structure, reducing axial space occupation, and lowering equipment manufacturing costs and on-site assembly difficulty. The bearings can continuously contact the internal lubricating oil of the machine body for self-lubrication and cooling, significantly reducing friction loss, improving transmission smoothness and component lifespan. Even under prolonged use, if lubricating oil leakage occurs, the intermediate housing cavity can collect the leaked lubricating oil from the compressor body. Furthermore, the sealed intermediate housing cavity prevents oil leakage to the outside (e.g., the compressor unit) and its impact on other components; the oil can be discharged centrally through a dedicated drain port.

[0021] Preferably, the cooling channel is arranged axially in the intermediate shell, and the intermediate shell is divided axially into a cooling zone with the cooling channel and a solid part located at both ends of the cooling zone. The oil drain is arranged in the solid part, and the solid part is used to maintain the radial positioning of the step and the intermediate shell.

[0022] Through the above technical solution, the intermediate shell is divided axially into a cooling zone with cooling channels and solid sections at both ends, achieving functional zoning of the shell structure. The cooling zone focuses on heat dissipation and cooling of the entire cavity to ensure stable compression conditions. The solid sections at both ends, without slots, have higher structural integrity and rigidity, ensuring stable radial positioning accuracy between the mating steps and the intermediate shell, avoiding rotor positioning misalignment caused by shell slot deformation, and continuously ensuring rotor coaxiality and accuracy. Simultaneously, the oil drain port is located in the solid area with higher structural strength. This avoids the problem of the oil drain port damaging the sealing and heat dissipation performance of the cooling channels, and effectively prevents shell cracking, air leakage, oil leakage, and other malfunctions. While ensuring stable oil drain and heat dissipation functions, it maximizes the preservation of overall structural strength, achieving a synergistic balance between structural strength, heat dissipation performance, and oil drain function.

[0023] Preferably, the screw shaft is connected to the bushing by a fixing member, the fixing member including a pad disposed inside the bushing and a fixing bolt passing through the pad, the fixing bolt being connected to the end of the screw shaft.

[0024] Preferably, the end of the fastener is not exposed outside the isolation end of the bushing.

[0025] Through the above technical solution, the structure can effectively avoid the interference of the fixed parts with the airflow and lubricating oil in the cavity when the equipment is running at high speed, eliminate problems such as abnormal wear of parts, airflow turbulence, and increased operating noise, and at the same time avoid the corrosion, dust and oil accumulation caused by exposed fixed parts, reduce the probability of equipment failure, ensure uniform and stable fit between rotor body and stator body, and further improve the overall machine's operating accuracy, smoothness and service life.

[0026] 3. Beneficial effects Compared with the prior art, the technical solution provided by this invention has the following advantages: (1) Compared with the exposed coupling connection method, a single drive source can drive two compressor bodies to move. At the same time, the input power shaft that is recessed and connected separately can achieve a shorter layout. The screw shaft end is recessed at the isolation end, and the center of gravity of the bushing is shifted to the compressor body side, which effectively reduces the rotor body cantilever length, replaces the traditional dual-motor dual-host axial redundant arrangement structure, effectively reduces the axial size of the unit, reduces the equipment footprint, and reduces the difficulty of space adaptation for transportation and on-site installation.

[0027] (2) When the intermediate shell is directly connected to the two compressor bodies, the interior of the intermediate shell is sealed. At the same time, the heat generated by the operation of the two rotor bodies is greater and cooling is required. The cooling medium dissipates heat and cools the entire working area of ​​the intermediate shell cavity, rotor body, and stator body. Meanwhile, a transmission gap is reserved between the bushing connection end and the docking shell to connect the inner wall of the intermediate shell, forming a dedicated directional heat dissipation channel.

[0028] (3) When the interior of the intermediate housing is sealed, and when the bearings are shared, there is a situation of lubricating oil leakage. The inner cavity of the intermediate housing can receive the lubricating oil leaked from the compressor body. The sealed inner cavity of the intermediate housing will not cause the oil to leak to the outside (e.g., the compressor unit) and affect other components. The oil can be discharged in a concentrated manner through a dedicated drain port. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of this application.

[0030] Figure 2 This is a partial sectional view of this application.

[0031] Figure 3 for Figure 2 Enlarged view of section A in the middle.

[0032] Figure 4 for Figure 2 Enlarged view of section B.

[0033] Explanation of reference numerals in the attached figures: 100. Intermediate shell; 110. Stator body; 120. Rotor body; 121. Bushing; 122. Connecting end; 123. Isolation end; 124. Fixing bolt; 125. Spacer block; 130. Cooling channel; 140. Cooling zone; 150. Solid part; 200, mating shell; 210, step; 220, annular groove; 230, transfer gap; 300. Compressor body; 310. Screw shaft; 330. Bearing; 400. Separation interval. Detailed Implementation

[0034] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0035] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0036] A dual-head compressor, reference Figure 1 , Figure 2It includes an intermediate shell 100 and two compressor bodies 300 disposed at both ends of the intermediate shell 100. The two compressor bodies 300 are a single-screw compressor and a twin-screw compressor, respectively. The intermediate shell 100 is cylindrical, with both ends being open and coaxial.

[0037] Reference Figure 2 , Figure 3 The intermediate housing 100 contains a single stator body 110. Each compressor body 300 has an independent screw shaft 310, the end of which is directly connected to a corresponding rotor body 120. The rotor body 120 and the screw shaft 310 form a single unit. The screw shaft 310 is connected to the rotor body 120 via a bushing 121. A docking shell 200 is provided at the end of the compressor body 300. The compressor body 300, together with the docking shell 200 and the screw shaft 310, is connected to the end of the intermediate housing 100. During connection, the docking shell 200 and the end of the compressor body 300 together seal the inner cavity of the intermediate housing 100. During installation, the two units are inserted and connected from both ends of the intermediate housing 100, so that the rotor body 120 extends and fits into the stator body 110, causing the screw shaft 310 to rotate. The screw shaft 310, in conjunction with the internal structure of the compressor body 300, forms a gas compression system.

[0038] Reference Figure 2 , Figure 4 The bushing 121 has a connecting end 122 and an isolating end 123 at its two ends. A screw shaft 310 extends inward and connects to the connecting end 122, while its end is recessed into the isolating end 123. The inner diameter of the isolating end 123 is larger than that of the connecting end 122, bringing the center of gravity of the bushing 121 closer to the compressor body 300. The end face of the screw shaft 310 is located within the axial thickness range of the rotor body 120, which is supported only by the connecting end 122. The screw shaft 310 supports the rotor body 120, but only at one end. Furthermore, the position of the screw shaft 310 within the bushing 121 further restricts the rotational stability of the rotor body 120, making its center closer to the compressor body 300.

[0039] The screw shaft 310 is connected to the bushing 121 by a fastener. Preferably, the fastener includes a pad 125 disposed inside the bushing 121 and a fixing bolt 124 passing through the pad 125. The fixing bolt 124 is connected to the end of the screw shaft 310. Furthermore, the end of the fastener is not exposed beyond the isolation end 123 of the bushing 121 to maintain the distribution of the center of gravity.

[0040] It is worth noting that a separation gap 400 exists between the two components, specifically at the isolating ends 123 of the two bushings 121, to separate the two rotor bodies 120, allowing them to operate independently and enabling the axial position of the rotor bodies 120 to be adjusted according to actual conditions. This separation gap 400 can extend axially within 10-80 mm, and is not limited to this distance. Even if there are obstructions between the two ends, it still constitutes a distance between the two rotor bodies 120. The separation gap 400 needs to be maintained at a lower limit, so that the two independent rotor bodies 120 do not interfere with each other during operation. However, it cannot be too large, as this would affect the overall length of the intermediate shell 100, and a longer intermediate shell 100 is more likely to experience radial displacement.

[0041] In this embodiment, the compressor body 300 is generally a screw compressor. The screw shaft 310, in conjunction with the internal structure of the compressor body 300, forms a gas compression effect. The specific internal structure is not detailed here. It is worth noting that the working chambers of the two compressor bodies 300 are independently separated. The compressor bodies 300 located at both ends of the intermediate shell 100 are different, resulting in different screw shafts 310 at both ends. This difference may be in length or thickness, and the two screw shafts 310 must be separate and independent, not the same shaft. It is noteworthy that, to ensure the reliable connection between the screw shaft 310 and the rotor body 120, the distance between the ends of the two screw shafts 310 in this embodiment is less than the length of the stator body 110. Furthermore, in this embodiment, both compressor bodies 300 are medium- and high-pressure air compressors, which have larger working pressures and larger footprints compared to refrigeration compressors.

[0042] In this embodiment, the screw compressor on one side has a twin-screw structure, with the end portion of the corresponding compressor body 300 embedded within the inner edge of the docking shell 200. The screw compressor on the other side has a single-screw structure, with the end of the corresponding compressor body 300 extending into the intermediate shell 100. The specific extension distance varies depending on the structure of the corresponding compressor body 300. Due to the differences between the two compressor bodies 300, the internal rotor bodies 120 may be asymmetrically positioned within the intermediate shell 100 after installation, although symmetrical positioning is possible. However, while maintaining a separation interval of 400, an asymmetrical rotor body 120 configuration can be formed, which also improves the compatibility of different screw compressors in the axial direction. Therefore, a stator body 110 is provided to enable the rotor bodies 120 in different positions to cooperate, but each rotor body 120 needs to have independent support stability, and the separation between rotor bodies 120 should not interfere with each other.

[0043] The docking shell 200 is used to install at the end of the intermediate shell 100. The docking shell 200 extends radially, and when it is installed at both ends of the intermediate shell 100, it will close both ends of the intermediate shell 100. Specifically, the docking shell 200 can be integrally set on the outer wall of the end of the compressor body 300, or it can be separately set at the end of the compressor body 300. In this embodiment, the docking shell 200 is set separately as an example. The docking shell 200 has a circular hole in the middle (inner edge portion) for the end of the compressor body 300 to be inserted, while the outer edge portion of the docking shell 200 is used to connect with the intermediate shell 100.

[0044] When the docking shell 200 is connected to the end of the intermediate shell 100, the rotor bodies 120 located at both ends of the intermediate shell 100 can remain coaxial and maintain the extension length of the separation interval 400. The term "maintain" here means that it can be limited within the originally required range. Theoretically, there is a certain possibility of offset, but the separation interval 400 is kept within the required range by axial limitation.

[0045] The intermediate shell 100 has a cooling channel 130 in its side wall, through which a flowing cooling medium is introduced. In this embodiment, the intermediate shell 100 is also provided with inlet and outlet channels (not shown in the figure) for circulating the cooling medium. In this embodiment, the cooling medium is cooling oil. The cooling channel 130 in the intermediate shell 100 can be spirally extended or have multiple individual annular structures. Alternatively, the intermediate shell 100 can be configured as two half-shells, or the cooling channel 130 can be arranged along the axial direction. However, in general, the axial extension distance of the cooling channel 130 needs to be sufficiently long, at least covering the axial length of the stator body 110. In this embodiment, the cooling channel 130 extends in a spiral shape.

[0046] During its flow, the cooling medium carries away the heat generated within the enclosed cavity of the intermediate shell 100. A transfer gap 230 exists between the connecting end 122 of the bushing 121 and the docking shell 200, directly connecting to the inner wall of the intermediate shell 100. The docking shell 200 and the compressor body 300 enclose the inner cavity of the intermediate shell 100. After the screw shaft 310 is connected to the bushing 121, it forms a heat conductor. The heat conductor transfers heat through the smaller cross-sectional area isolation end 123 to the larger cross-sectional area connecting end 122, guiding the heat to the transfer gap 230. The different inner diameters of the connecting end 122 and the isolation end 123 of the bushing 121 not only improve the stability of the single-sided supported rotor body 120 but also create a better heat conduction path through the different solid cross-sectional areas, resulting in efficient heat dissipation within the enclosed cavity of the intermediate shell 100.

[0047] The docking shell 200 has steps 210 that are continuously or intermittently arranged along the circumference. In this embodiment, the step 210 is a continuous ring. The intermediate shell 100 has an annular groove 220 for the step 210 to be embedded in, and the step 210 is connected to the inner wall of the annular groove 220. At the same time, the docking shell 200 allows the outer diameter side of the step 210 to simultaneously position the radial positions of the compressor body 300 and the rotor body 120 when the step 210 and the annular groove 220 are engaged, and the inner diameter side of the step 210 to close the internal cavity of the intermediate shell 100.

[0048] In general, in existing technologies, the compressor body 300 is connected to the drive motor via a coupling, and a cooling fan is located at one end of the intermediate shell 100, or cooling fins are directly installed on the intermediate shell 100.

[0049] Furthermore, since both ends of the actual intermediate shell 100 are connected to the compressor body 300, continuing to use a cooling fan structure located at the ends has the following drawbacks: If a symmetrical structure is formed, there will be at least two cooling fan structures located at the ends, resulting in a relatively long overall length. Also, with connections at both ends, the air in the original cooling fan structure needs to flow axially, passing through the stator body 110 and rotor body 120 before being discharged from the ends. However, with components at both ends, this axial flow method already creates obstruction. If fans are only placed at both ends of the intermediate shell, the cooling effect is insufficient because the heat dissipation is already doubled. Placing a fan at one end will lead to poor heat dissipation at the other end, resulting in a significant difference in cooling performance between the two ends. Moreover, in the original structure, the axial airflow of the fans will cause different air pressures at both ends. With two rotor bodies 120, this will lead to instability in the air gap, affecting the overall operation of the rotor body 120.

[0050] Furthermore, the fans need to rotate synchronously, which inevitably has a radial impact during rotation. Additionally, after prolonged use, some fan blades may have impurities, causing radial imbalance during rotation. Moreover, since the rotor 120 in this embodiment needs to drive the screw shafts 310 at both ends, and the compressor bodies 300 at both ends are of different types, the impact of the cooling fan on the screw shafts 310 is amplified.

[0051] Furthermore, the end of the compressor body 300 extends into the intermediate housing 100. A bearing 330 is provided on the side of the screw shaft 310 near the connecting end 122. The rotor body 120 and the screw shaft 310 share the bearing 330. One side of the bearing 330 contacts the lubricating oil located inside the compressor body 300. The lubrication of the bearing 330 can be achieved by the circulation of the lubricating oil within the compressor body 300 itself, and there is no need to add additional bearings 330 at both ends of the intermediate housing 100.

[0052] In the case of shared bearing 330, oil leakage may occur on one side of bearing 330 during prolonged use. The enclosed inner cavity of intermediate shell 100 can be used to collect lubricating oil leaking from the compressor body 300. In this embodiment, the stator body 110 and rotor body 120 are also wrapped with a protective layer, generally an epoxy resin layer, to prevent direct impact on the internal structure. In conventional structures, lubricating oil would leak to the outside, requiring timely cleaning to avoid contamination. In this embodiment, however, the lubricating oil flows into intermediate shell 100 and does not overflow. To a certain extent, it can lubricate the rotor body 120. When there is too much lubricating oil, it can be cleaned periodically by opening intermediate shell 100, or drained through an additional external valve. For drainage, intermediate shell 100 is provided with an oil drain port (not shown in the figure).

[0053] As mentioned above, refer to Figure 2 The cooling channel 130 is axially disposed in the intermediate shell 100. The intermediate shell 100 is axially divided into a cooling zone 140 with the cooling channel 130 and solid portions 150 located at both ends of the cooling zone 140. The oil drain port is disposed in the solid portion 150, which is used to maintain the radial positioning of the step 210 and the intermediate shell 100. The intermediate shell 100 realizes a series of functions including connection, support, cooling, positioning, and oil drainage.

[0054] Furthermore, in this embodiment, both the stator body 110 and the rotor body 120 are coated with rubber to prevent oil leakage from affecting the stator body 110 and the rotor body 120 inside the intermediate shell 100.

[0055] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited to this. It is worth noting that the various embodiments are not completely independent; they are combined together to express the technical solution as a whole. Furthermore, provided that the various embodiments do not conflict technically, the various technical features can be combined without exceeding the scope of this application. Therefore, if those skilled in the art, inspired by this description, design similar structures and embodiments without departing from the spirit of the invention, they should all fall within the protection scope of this invention.

Claims

1. A dual-head compressor, characterized in that: include Two compressor bodies (300), one a single-screw compressor and the other a twin-screw compressor; The intermediate shell (100) is open at both ends, and a single stator (110) is provided inside the intermediate shell (100). The compressor body (300) has a screw shaft (310) extending into the intermediate shell (100), and a docking shell (200) is provided at the end of the compressor body (300). The docking shell (200) and the end of the compressor body (300) together seal the inner cavity of the intermediate shell (100). The screw shaft (310) is connected to the rotor body (120) through the bushing (121). When the docking shell (200) is connected to the end of the intermediate shell (100), the rotor body (120) extends inward and cooperates with the stator body (110) to form rotation. The rotor body (120) drives the screw shaft (310) to cooperate with the internal structure of the compressor body (300) to form gas compression. The two ends of the bushing (121) are the connecting end (122) and the isolating end (123), respectively. The screw shaft (310) extends inward and is connected to the connecting end (122). The end of the screw shaft (310) is recessed inward to the isolating end (123). The inner diameter of the isolating end (123) is larger than that of the connecting end (122), so that the center of gravity of the bushing (121) is closer to the compressor body (300). The shaft end face of the screw shaft (310) is located within the thickness range of the rotor body (120) along the axial direction. The rotor body (120) is supported only by the connecting end (122).

2. A dual-head compressor according to claim 1, characterized in that: When the screw shaft (310) with the rotor body (120) is inserted from one end of the intermediate shell (100), the mating shell (200) simultaneously limits the axial and radial positions of the rotor body (120), so that there is a separation gap (400) between the isolation ends (123) of the two bushings (121), so that the two rotor bodies (120) can work independently.

3. A dual-head compressor according to claim 2, characterized in that: The docking shell (200) is symmetrically arranged at both ends of the intermediate shell (100), and the two rotor bodies (120) are symmetrically or asymmetrically arranged inside the intermediate shell (100) to adapt to the same or different screw shafts (310).

4. A dual-head compressor according to claim 2, characterized in that: A cooling channel (130) is provided in the side wall of the intermediate shell (100). Cooling medium is introduced into the cooling channel (130) to remove the heat generated in the closed inner cavity of the intermediate shell (100). There is a transmission gap (230) between the connecting end (122) of the bushing (121) and the mating shell (200). The transmission gap (230) is directly connected to the inner wall of the intermediate shell (100).

5. A dual-head compressor according to claim 4, characterized in that: After the screw shaft (310) is connected to the bushing (121), it forms a heat conductor. The heat conductor is transferred through the smaller cross-sectional area isolation end (123) to the larger cross-sectional area connection end (122) to guide the heat to the transfer gap (230).

6. A dual-head compressor according to claim 5, characterized in that: The docking shell (200) is provided with a step (210) arranged circumferentially. The step (210) is inserted axially to the end of the intermediate shell (100). The outer diameter side of the step (210) is used to simultaneously position the radial position of the compressor body (300) and the rotor body (120). The inner diameter side of the step (210) is used to close the internal cavity of the intermediate shell (100).

7. A dual-head compressor according to claim 5, characterized in that: A bearing (330) is provided on the side of the screw shaft (310) near the connecting end (122). The rotor body (120) and the screw shaft (310) share the bearing (330). One side of the bearing (330) contacts the lubricating oil inside the compressor body (300). The rotor body (120) and the stator body (110) are rubber-coated. The inner cavity of the intermediate shell (100) can be used to receive the lubricating oil leaking from inside the compressor body (300). The intermediate shell (100) is provided with an oil drain port.

8. A dual-head compressor according to claim 7, characterized in that: The cooling channel (130) is axially disposed on the intermediate shell (100). The intermediate shell (100) is axially divided into a cooling area (140) with the cooling channel (130) and a solid part (150) located at both ends of the cooling area (140). The oil drain is disposed on the solid part (150). The solid part (150) is used to maintain the radial positioning of the step (210) and the intermediate shell (100).

9. A dual-head compressor according to claim 1, characterized in that: The screw shaft (310) is connected to the bushing (121) by a fastener. The fastener includes a pad (125) inside the bushing (121) and a fixing bolt (124) passing through the pad (125). The fixing bolt (124) is connected to the end of the screw shaft (310).

10. A dual-head compressor according to claim 9, characterized in that: The end of the fastener is not exposed outside the isolation end (123) of the bushing (121).

Images