Novel driving structure of two-stage oil injection screw compressor

Abstract

The utility model discloses a novel driving structure of a two-stage oil injection screw compressor. The second-stage compressor driving mechanism comprises a second-stage compressor male rotor, a second-stage compressor female rotor and a driving motor, on the exhaust side of the second-stage compressor, the second-stage compressor male rotor is connected with the driving motor, and the second-stage compressor male rotor is meshed with the second-stage compressor female rotor; the first-stage compressor driving mechanism comprises a first-stage compressor male rotor and a first-stage compressor female rotor, on the air inlet side of the second-stage compressor, the second-stage compressor male rotor is connected with the first-stage compressor female rotor through the transmission mechanism, and the first-stage compressor female rotor is meshed with the first-stage compressor male rotor; in the first-stage compressor, a first-stage compressor female rotor serves as a driving shaft, and a first-stage compressor male rotor serves as a driven shaft. The total power consumption of the two-stage compressor is reduced.

Description

Technical field:

[0001] The utility model belongs to the technical field of screw compressors, and in particular relates to a novel driving structure of a two-stage oil-injected screw compressor. Background technology:

[0002] Compressors are a common type of mechanical equipment in industrial production, widely used in a variety of industries, including mining, chemical engineering, power generation, and refrigeration, forming a vital component of the modern industrial system. However, they are also energy-intensive, accounting for approximately 10% of China's total electricity generation. Compressors primarily come in piston, rotary, and vane types, with screw compressors being a type of rotary compressor. In a society that strongly advocates energy conservation and emission reduction, the vast majority of single-stage, industrial frequency, oil-injected screw compressors currently operate at energy efficiency levels of Class II or even Class III. To improve the efficiency of oil-injected screw compressors, a growing number of manufacturers are adopting two-stage, oil-injected screw compressors.

[0003] Two-stage oil-injected screw compressors, whether in the first or second stage, typically use a male rotor as the drive shaft. Under no-load conditions, the first-stage compressor's suction and discharge pressures (also known as intermediate pressure) are both negative. The pressure differential between the inlet and discharge pressures is minimal, resulting in insufficient gas force on the rotors, especially on the female rotor, which acts as the driven shaft, leading to unstable operation. Furthermore, the first-stage compressor's bearings experience brief periods of light load and slippage, shortening their lifespan. This is manifested externally as increased noise and poor sound quality from the screw compressor.

[0004] Traditional two-stage oil-injected screw compressors typically increase the exhaust pressure (i.e., intermediate pressure) of the first-stage compressor by increasing the intermediate pressure, thereby increasing the pressure differential between the inlet and exhaust, and stabilizing the operation of the female rotor. However, this approach also increases the screw compressor's power consumption when no-load. Green product design evaluations for compressors generally require that no-load power be no more than 30% of the unit power. Resolving female rotor instability by increasing the intermediate pressure often results in no-load power exceeding 30% of the unit power.

[0005] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. Utility model content:

[0006] The purpose of this utility model is to provide a new driving structure for a two-stage oil-injected screw compressor, which ensures that the female rotor of the first-stage compressor is always in a positive torque, thereby stabilizing the operating state of the female rotor, eliminating the abnormal noise problem of the screw compressor under no-load conditions, and not increasing the energy consumption under no-load conditions, thereby overcoming the defects in the above-mentioned prior art.

[0007] To achieve the above-mentioned objectives, the utility model provides a novel two-stage oil-injected screw compressor drive structure, including a first-stage compressor drive mechanism and a second-stage compressor drive mechanism, wherein the first-stage compressor drive mechanism is connected in series with the second-stage compressor drive mechanism; the second-stage compressor drive mechanism includes a second-stage compressor male rotor, a second-stage compressor female rotor, and a drive motor, and on the exhaust side of the second-stage compressor, the second-stage compressor male rotor is connected to the drive motor, and the second-stage compressor male rotor is meshed with the second-stage compressor female rotor; in the second-stage compressor, the second-stage compressor male rotor serves as the main drive shaft, and the second-stage compressor female rotor serves as the driven shaft; the first-stage compressor drive mechanism includes a first-stage compressor male rotor and a first-stage compressor female rotor, and on the intake side of the second-stage compressor, the second-stage compressor male rotor is connected to the first-stage compressor female rotor through a transmission mechanism, and the first-stage compressor female rotor is meshed with the first-stage compressor male rotor; in the first-stage compressor, the first-stage compressor female rotor serves as the drive shaft, and the first-stage compressor male rotor serves as the driven shaft.

[0008] Preferably, in the technical solution, in the first-stage compressor, a rotor meshing band is formed at the meshing point between the first-stage compressor male rotor and the first-stage compressor female rotor, and the contact band width of the first-stage compressor female rotor profile in the rotor meshing band is greater than the contact band width of the compressor female rotor profile where the male rotor drives the female rotor, and the first-stage compressor male rotor and the first-stage compressor female rotor form a "female driving male" profile.

[0009] Preferably, in the technical solution, the transmission mechanism is a gear transmission, and the transmission mechanism includes a driving gear and a driven gear. The driving gear and the driven gear are arranged on the intake side of the second-stage compressor. The driving gear is connected to the male rotor of the second-stage compressor, and the driven gear is connected to the female rotor of the first-stage compressor. The driving gear and the driven gear are meshed.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] In the first-stage compressor, the female rotor serves as the drive shaft, stabilizing its no-load operation. This reduces intermediate pressure and significantly reduces the compressor's unloaded operating conditions, effectively reducing the overall power consumption of both stages. The male and female rotors of the first-stage compressor utilize a "female-driven male" profile design, effectively minimizing rotor wear during high-speed operation. Description of the drawings:

[0012] Figure 1 This is a schematic diagram of the drive structure of the new two-stage oil-injected screw compressor of the utility model;

[0013] Figure 2 for Figure 1 Magnified view of part A. Specific implementation method:

[0014] The specific implementation methods of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific implementation methods.

[0015] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0016] like Figure 1-2 As shown, a new type of two-stage oil-injected screw compressor drive structure includes a first-stage compressor drive mechanism and a second-stage compressor drive mechanism. The first-stage compressor drive mechanism is connected in series with the second-stage compressor drive mechanism; the second-stage compressor drive mechanism includes a second-stage compressor male rotor 1, a second-stage compressor female rotor 2, and a drive motor 3. On the exhaust side of the second-stage compressor, the second-stage compressor male rotor 1 is connected to the drive motor 3, and the second-stage compressor male rotor 1 is meshed with the second-stage compressor female rotor 1; in the second-stage compressor, the second-stage compressor male rotor 1 serves as the main drive shaft, and the second-stage compressor female rotor 2 serves as the driven shaft; the first-stage compressor driving mechanism includes a first-stage compressor male rotor 4 and a first-stage compressor female rotor 5, and the transmission mechanism is a gear transmission, and the transmission mechanism includes a driving gear 6 and a driven gear 7. The driving gear 6 and the driven gear 7 are arranged on the intake side of the second-stage compressor, the driving gear 6 is connected to the second-stage compressor male rotor 1, and the driven gear 7 is connected to the first-stage compressor female rotor 5. The driving gear 6 is meshed with the driven gear 7, and the first-stage compressor female rotor 5 is meshed with the first-stage compressor male rotor 4; in the first-stage compressor, the first-stage compressor female rotor 5 serves as a driving shaft, and the first-stage compressor male rotor 4 serves as a driven shaft.

[0017] In the first-stage compressor, the meshing portion of the first-stage compressor male rotor 4 and the first-stage compressor female rotor 5 forms a rotor meshing band 8. The width of the contact band 9 of the first-stage compressor female rotor 5 profile in the rotor meshing band 8 is greater than the width of the contact band of the compressor female rotor profile where the male rotor drives the female rotor. The first-stage compressor male rotor 4 and the first-stage compressor female rotor 5 form a "female driving male" profile. In the first-stage compressor, female driving male will cause the rotor contact force to increase, exacerbating rotor wear. Therefore, in the profile design, increasing the width of the contact band 9 of the first-stage compressor female rotor 5 profile effectively reduces rotor wear during high-speed operation.

[0018] The drive motor 3 transmits torque from the second-stage compressor male rotor 1 to the first-stage compressor female rotor 5 via the driving gear 6 and the driven gear 7. In the first and second-stage compressors, the intermeshing female and male rotors and the casing together form a pair of closed volumes. As the rotors continuously rotate, the medium's intake, compression, and exhaust processes are achieved. In the first-stage compressor, the first-stage compressor female rotor 5 serves as the drive shaft, and its operation remains stable even under no-load conditions and when the gas force on the first-stage compressor female rotor 5 is very small. However, due to the characteristics of the compressor, the gas force on the first-stage compressor male rotor 4 is often greater than that on the first-stage compressor female rotor 5, and the first-stage compressor male rotor 4 always experiences positive torque, preventing alternating positive and negative torques and unstable rotor operation. The exhaust pressure of the second-stage compressor can generally be maintained above 2 bar under all operating conditions, and the inlet and exhaust pressure differential will not be too low. Therefore, in two-stage compression, the second-stage compressor still uses a male-driven female drive structure. The driving structure of the new two-stage oil-injected screw compressor can stabilize the operating state of the female rotor 5 of the first-stage compressor under no-load conditions, reduce the intermediate pressure of the compressor, greatly reduce the unloading condition of the compressor, and thus effectively reduce the total power consumption of the two-stage compressor.

[0019] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the present invention to the precise forms disclosed, and it is apparent that many modifications and variations are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the present invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the present invention and various options and variations. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A new type of two-stage oil-injected screw compressor drive structure, characterized by: It includes a first-stage compressor drive mechanism and a second-stage compressor drive mechanism, wherein the first-stage compressor drive mechanism and the second-stage compressor drive mechanism are connected in series; The second-stage compressor driving mechanism includes a second-stage compressor male rotor, a second-stage compressor female rotor, and a driving motor. On the exhaust side of the second-stage compressor, the second-stage compressor male rotor is connected to the driving motor and meshes with the second-stage compressor female rotor. In the second-stage compressor, the second-stage compressor male rotor serves as the main driving shaft and the second-stage compressor female rotor serves as the driven shaft. The first-stage compressor driving mechanism includes a first-stage compressor male rotor and a first-stage compressor female rotor. On the intake side of the second-stage compressor, the second-stage compressor male rotor is connected to the first-stage compressor female rotor through a transmission mechanism, and the first-stage compressor female rotor is engaged with the first-stage compressor male rotor; in the first-stage compressor, the first-stage compressor female rotor serves as a driving shaft, and the first-stage compressor male rotor serves as a driven shaft.

2. The driving structure of the novel two-stage oil-injected screw compressor according to claim 1 is characterized in that: In the first-stage compressor, a rotor meshing band is formed at the meshing point between the first-stage compressor male rotor and the first-stage compressor female rotor. The contact band width of the first-stage compressor female rotor profile in the rotor meshing band is greater than the contact band width of the compressor female rotor profile where the male rotor drives the female rotor. The first-stage compressor male rotor and the first-stage compressor female rotor form a "female driving male" profile.

3. The driving structure of the novel two-stage oil-injected screw compressor according to claim 1 is characterized in that: The transmission mechanism is a gear transmission, which includes a driving gear and a driven gear. The driving gear and the driven gear are arranged on the intake side of the second-stage compressor. The driving gear is connected to the male rotor of the second-stage compressor, and the driven gear is connected to the female rotor of the first-stage compressor. The driving gear and the driven gear are meshed.

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