Semi-closed compressor based on built-in motor

Abstract

The invention provides a semi-closed compressor based on a built-in motor, and aims to solve the problems of low transmission efficiency, easy leakage and high cost of an open compressor in the prior art. The compression module comprises a base flange, a motor cavity shell, a compression module cavity and an internal motor assembly. According to the invention, the motor is internally arranged to realize full sealing, so that a dynamic shaft seal which is easy to leak is eliminated fundamentally, absolute sealing of hazardous gas is achieved, and the safety is higher; the motor rotor and the compressor spindle are integrated in a direct-drive mode, transmission parts such as couplers are omitted, and the transmission efficiency is improved; a dual cooling scheme of medium internal circulation cooling and stator independent cooling is adopted; a medium flows through the interior of the motor along a preset path, so that heat is effectively taken away; the independent stator cooler strengthens heat dissipation, and solves the problem of motor cooling when the air quantity is insufficient; the compressor integrated structure is high in air inlet temperature adaptability and can still stably operate even under the high-temperature working condition of 100 DEG C or above, and the application scene is greatly widened.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to a semi-hermetic compressor based on a built-in motor. Background Technology

[0002] In industrial applications, the compression of hazardous gases such as hydrogen, natural gas, and carbon monoxide places extremely high demands on the sealing and safety of equipment. Currently, compressors used for compressing these hazardous gases are primarily open-type compressors. In this type of structure, the electric motor and the compressor body are independent of each other, with power transmitted via a coupling or belt. Because the compressor shaft needs to extend from inside the housing to connect to the external motor, a complex shaft sealing device, such as a dry gas seal or a magnetohydrodynamic seal, must be installed at the shaft extension point to prevent leakage of internal hazardous gases.

[0003] However, existing open-type compressor designs have the following drawbacks: First, leakage cannot be completely avoided: dry gas seals themselves allow for trace amounts of process gas leakage. These leaked gases mix with the sealing gas and need to be vented or rendered harmless in a specific area. However, the risk of leakage still exists, which is unacceptable for extremely dangerous or high-value media.

[0004] Secondly, limitations and high costs: The performance of magnetohydrodynamic (MHD) seals is limited by various factors such as spindle diameter, operating temperature, and compatibility between the base fluid and the sealed medium, resulting in a narrow range of applications. Furthermore, both dry gas seals and MHD seals are extremely expensive to manufacture, use, and maintain.

[0005] Third, transmission efficiency loss: Using couplings or belt drives introduces additional mechanical transmission losses, reducing the energy efficiency of the entire system.

[0006] Therefore, there is an urgent need in this field for a compressor solution that can fundamentally solve the problem of hazardous gas leakage while possessing high reliability and high efficiency. Summary of the Invention

[0007] To address the shortcomings of the prior art, this application provides a semi-hermetic compressor based on a built-in motor. The invention constructs a semi-hermetic compressor suitable for hazardous gases, completely leak-free, with high cooling efficiency and reliable operation through direct-drive built-in motor, unique gas medium cooling path, independent stator forced cooling, and multiple static seals.

[0008] The technical solution adopted in this invention is as follows: A semi-hermetic compressor based on a built-in motor, comprising: The base flange, motor cavity housing, and compression module cavity are connected sequentially from bottom to top. The motor cavity housing and the compression module cavity together form a buffer cavity for compressor intake buffering. The motor assembly is disposed within the motor cavity housing. The motor assembly includes a motor stator housing, a motor stator disposed within the housing, a motor rotor, and a compressor main shaft. The main shaft is fitted into the center of the motor rotor to achieve direct drive integration. The bottom of the motor stator housing is also provided with an auxiliary bearing seat, and the upper part of the main bearing is also provided with a main bearing. The auxiliary bearing housing is provided with multiple cooling channels, and the main shaft has a deep hole machined in the center. The gas medium first enters the deep hole from the gas inlet of the base flange, and then is guided through the cooling channels to pass through the inner cavity of the auxiliary bearing housing, through the motor stator and motor rotor to the main bearing, and finally enters the compressor intake buffer chamber.

[0009] Furthermore, an auxiliary bearing is provided inside the auxiliary bearing housing, and one end of the main shaft is rotatably installed inside the auxiliary bearing. The end of the main shaft near the base flange is machined with a deep hole leading to the interior of its shaft body. The center of the auxiliary bearing housing corresponds to the center of the base flange and is an annular cavity. Multiple cooling channels extending to the far end of the auxiliary bearing housing are evenly distributed on the annular cavity. The ends of the cooling channels on the auxiliary bearing housing penetrate through the upper surface of the auxiliary bearing housing and can be ejected.

[0010] Furthermore, the motor stator and motor rotor together form an upper cooling cavity with the inner wall structure of the motor stator housing, and a lower cooling cavity with the inner wall structure of the motor stator housing and the auxiliary bearing seat.

[0011] Furthermore, it also includes a motor stator cooler, which is disposed on the outside of the motor stator and inside the motor stator housing. The motor stator cooler is equipped with a spiral groove, and a cooling medium inlet is opened at one end of the motor stator housing and a cooling medium outlet is opened at the other end, forming a stator cooling circuit.

[0012] Furthermore, a sealing gasket is provided between the auxiliary bearing housing and the motor stator housing.

[0013] Furthermore, a sealing groove is provided between the motor cavity housing, the auxiliary bearing housing, and the motor stator housing and the base flange; The motor stator housing and the base flange are connected by bolts; The motor cavity housing and the base flange are connected by bolts.

[0014] Furthermore, a sealing groove is provided between the motor cavity housing and the motor stator housing.

[0015] Furthermore, both the auxiliary bearing and the main bearing are sealed grease-lubricated bearings.

[0016] The advantages of this invention over the prior art are as follows: (1) By incorporating the motor, the compressor system is completely sealed, which fundamentally eliminates the dynamic shaft seal (such as dry gas seal and magnetohydrodynamic seal) that is necessary for traditional open compressors and is prone to leakage. This achieves absolute sealing of dangerous gases and is extremely safe. (2) The motor rotor is directly integrated with the compressor main shaft, eliminating intermediate transmission components such as couplings or belts, reducing mechanical energy loss and improving the transmission efficiency of the entire drive system; (3) The built-in motor structure of the present invention also adopts a dual cooling scheme combining internal medium circulation cooling and independent stator cooling. The compressed medium gas flows through the motor along a specific path, namely, through the base flange inlet, the main shaft deep hole, the auxiliary bearing cavity, the lower cooling cavity, the air gap between the motor stator and the motor rotor, the upper cooling cavity, and the main bearing, effectively carrying away a large amount of heat generated by the motor rotor and stator. The independent motor stator cooler can force-cool the motor stator, which is especially suitable for working conditions where the gas volume is small but the motor power is large, solving the problem of insufficient cooling by relying solely on intake air; due to the independent and powerful cooling system, the present invention has a wider adaptability to intake air temperature, and even if the intake air temperature is as high as 100°C or above, it can ensure reliable cooling and stable operation of the motor, thus broadening the application scenarios. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of the present invention; Figure 2 This is a three-dimensional structural diagram of the present invention; Figure 3 This is a schematic diagram of the motor assembly in this invention; Figure 4 This is a schematic diagram of the internal structure of the auxiliary bearing housing in this invention.

[0018] The components include: 1. Bearing; 2. Locking nut; 3. Auxiliary bearing housing; 4. Stator and bearing mounting base; 5. Base flange; 6. Motor cavity housing; 7. Compression module cavity; 8. Motor stator cooler; 9. Motor stator; 10. Motor rotor; 11. Main bearing; 12. Main bearing pressure plate; 13. Locking nut; 14. Main shaft; 15. Deep hole. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0020] Reference Figures 1 to 4The overall structure of this semi-hermetic compressor, from bottom to top, includes a base flange 5, a motor housing 6, and a compression module cavity 7. These three components are tightly connected by fastening bolts, forming a sealed container capable of withstanding internal pressure. The motor housing 6 and the compression module cavity 7 together enclose a compressor intake buffer chamber.

[0021] The entire motor assembly is housed within the motor housing 6. The motor assembly mainly includes the motor stator housing 4, the motor stator 9, the motor rotor 10, and the main shaft 14. The motor stator 9 is installed inside the motor stator housing 4, and the motor rotor 10 is directly mounted on the main shaft 14, realizing direct drive integration between the motor and the compressor. This eliminates all external couplings or belt drive mechanisms, fundamentally eliminating shaft seal leakage points in the power transmission process.

[0022] Furthermore, structurally, to meet bearing support requirements and ensure the high-speed stable operation of the main shaft 14, an auxiliary bearing housing 3 is fixedly installed at the bottom of the motor stator housing 4 using bolts and sealing gaskets. An auxiliary bearing 1 is installed inside the auxiliary bearing housing 3, and one end of the main shaft 14 is rotatably supported within this auxiliary bearing 1 and axially fixed by a lock nut 2. At the upper part of the motor stator housing 4, a main bearing 11 is installed, supporting the other end of the main shaft 14 and axially fixed by a main bearing pressure plate 12 and another lock nut 13. In a preferred embodiment, both the auxiliary bearing 1 and the main bearing 11 are sealed grease-lubricated bearings to adapt to oil-free lubrication conditions.

[0023] The working process of the gas medium cooling channel is as follows: The gas medium enters from the center of the base flange 5, i.e., the gas inlet. First, the gas medium enters the axial deep hole 15 machined at the air inlet end of the main shaft 14, where the airflow is buffered and the main shaft 14 is initially cooled. Then, the medium enters the annular cavity in the center of the auxiliary bearing housing 3 to cool the auxiliary bearing 1. Next, the gas medium passes through four cooling channels evenly distributed on the auxiliary bearing housing 3 (the number is not limited, as long as they are evenly distributed) and is ejected at the end, entering the lower cooling cavity formed by the lower coil of the motor stator 9 and the inner wall of the motor stator housing 4. In this cavity, the ejected airflow creates strong turbulence, efficiently cooling the lower part of the motor stator 9.

[0024] Subsequently, driven by the fan blades on the motor rotor 10, the medium flows upward, entering the air gap between the motor stator 9 and the motor rotor 10, and the upper cooling cavity formed by the inner side of the motor stator 9 coil and the motor rotor 10. During this process, it continuously removes heat from the motor stator 9 and the motor rotor 20. After cooling the motor part is completed, the medium continues to flow upward to cool the upper main bearing 11. Finally, the medium that has cooled the motor and bearing flows out through the channel opened in the upper part of the motor stator housing 4, enters the compressor intake buffer cavity formed by the motor cavity housing 6 and the compression module cavity 7, and is then compressed by the compression module and discharged.

[0025] This invention also includes a separate stator cooler 8, primarily used for enhanced cooling of high-power motors and high-temperature intake conditions. A motor stator cooler 8 is integrated externally into the motor stator 9 and tightly fitted internally into the motor stator housing 4. This cooler 8 is machined with spiral grooves, and its ends are welded closed, forming an independent, sealed cooling chamber. The motor stator housing 4 has a cooling medium inlet and outlet machined on it, communicating with this spiral groove chamber. External cooling medium (such as cooling water or oil) flows in from the inlet, flows within the spiral grooves, directly and powerfully cooling the motor stator 9, and then exits from the outlet, forming an independent stator cooling circuit.

[0026] Furthermore, all static connection interfaces of the present invention are equipped with reliable sealing structures: a sealing gasket is provided between the auxiliary bearing housing 3 and the motor stator housing 4, which serves both as a seal and as an axial positioning element for the auxiliary bearing housing 3. Sealing grooves are machined between the motor stator housing 4 and the base flange 5, and between the motor cavity housing 6 and the base flange 5, and O-rings are installed and tightened by bolts; a sealing groove is also provided between the motor cavity housing 6 and the motor stator housing 4, and an O-ring is installed. These multiple static sealing structures work together to ensure that the hazardous gas medium is completely enclosed within the compressor system and cannot leak into the external environment.

[0027] In summary, this invention constructs a semi-hermetic compressor suitable for hazardous gases, completely leak-free, with efficient cooling and reliable operation, through direct-drive motor integration, a unique gas medium cooling path, independent stator forced cooling, and multiple static seals.

[0028] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A semi-hermetic compressor based on a built-in motor, characterized in that: include The base flange (5), motor cavity housing (6), and compression module cavity (7) are connected sequentially from bottom to top. The motor cavity housing (6) and the compression module cavity (7) together form a buffer cavity for compressor intake buffering. The motor assembly is disposed within the motor cavity housing (6). The motor assembly includes a motor stator housing (4), a motor stator (9) disposed within the housing, a motor rotor (10), and a compressor main shaft (14). The main shaft (14) is fitted into the center of the motor rotor (10) to achieve direct drive integration. The bottom of the motor stator housing is also provided with an auxiliary bearing seat (3), and the upper part is also provided with a main bearing (11). The auxiliary bearing housing (3) is provided with multiple cooling channels. The main shaft (14) has a deep hole (15) machined in the center. The gas medium enters the deep hole from the gas inlet of the base flange (5). The gas medium is then guided through the cooling channel through the inner cavity of the auxiliary bearing housing (3), flows through the motor stator (9) and the motor rotor (10) straight main bearing (11), and finally enters the compressor intake buffer chamber.

2. A semi-hermetic compressor based on a built-in motor as described in claim 1, characterized in that: An auxiliary bearing (1) is provided inside the auxiliary bearing housing (3). One end of the main shaft (14) is rotatably installed inside the auxiliary bearing (1). The end of the main shaft (14) near the base flange (5) is machined with a deep hole (15) leading to the inside of its shaft body. The center of the auxiliary bearing housing (3) is an annular cavity corresponding to the center of the base flange (5). Multiple cooling channels extending to the far end of the auxiliary bearing housing (3) are evenly distributed on the annular cavity. The ends of the cooling channels on the auxiliary bearing housing (3) penetrate through the upper surface of the auxiliary bearing housing (3) and can be sprayed out.

3. A semi-hermetic compressor based on a built-in motor as described in claim 1, characterized in that: The motor stator (9) and the motor rotor (10) form an integral whole. The upper part of the stator and the inner wall structure of the motor stator housing (4) form an upper cooling cavity, and the lower part of the stator and the inner wall structure of the motor stator housing (4) and the auxiliary bearing seat (3) together form a lower cooling cavity.

4. A semi-hermetic compressor based on a built-in motor as described in claim 1, characterized in that: It also includes a motor stator cooler (8), which is located outside the motor stator (9) and inside the motor stator housing (4). The motor stator cooler (8) is equipped with a spiral groove. A cooling medium inlet is opened at one end of the motor stator housing (4), and a cooling medium outlet is opened at the other end, forming a stator cooling circuit.

5. A semi-hermetic compressor based on a built-in motor as described in claim 1, characterized in that: A sealing gasket is provided between the auxiliary bearing housing (3) and the motor stator housing (4).

6. A semi-hermetic compressor based on a built-in motor as described in claim 1, characterized in that: The motor cavity housing (6), auxiliary bearing seat (3) and motor stator housing (4) are all provided with sealing grooves between themselves and the base flange (5); The motor stator housing (4) and the base flange (5) are connected by bolts; The motor cavity housing (6) and the base flange (5) are connected by bolts.

7. A semi-hermetic compressor based on a built-in motor as described in claim 1, characterized in that: A sealing groove is provided between the motor cavity housing (6) and the motor stator housing (4).

8. A semi-hermetic compressor based on a built-in motor as described in claim 2, characterized in that: Both the auxiliary bearing (1) and the main bearing (11) are sealed grease-lubricated bearings.

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