Oil injection screw compressor

Abstract

The utility model provides an oil injection screw type compressor. A pair of female rotor and male rotor of which molded lines are meshed with each other is arranged in a compression cavity; the female rotor and the male rotor are parallel in axis and opposite in rotation direction; rotor shafts of the female rotor and the male rotor are respectively provided with a bearing. A suction inlet is formed in the lower shell, and an exhaust outlet is formed in the upper shell; the inner wall face of the compression cavity is provided with a contour shape tightly matched with the female rotor and the male rotor, and when the compressor rotor rotates, the suction inlet and the exhaust outlet are separated through the contour. A motor shell of the motor is connected with the upper shell through a transition flange; lubricating oil is injected into the compressor through the transition flange, firstly flows into the motor shell cooling motor, then is connected to the upper shell of the compressor through an external pipeline, and is injected into the compression cavity and bearings on rotor shafts of the female rotor and the male rotor through an internal pipeline for cooling and lubricating, and the lubricating oil and compressed gas are mixed and discharged through the exhaust outlet.

Description

Technical Field

[0001] This utility model relates to a screw compressor. Background Technology

[0002] In currently known oil-injected screw compressors, to drive the compressor rotor, the motor rotor shaft is typically indirectly connected to the compressor rotor extension shaft via belts, couplings, or other methods, or driven directly. Regardless of the connection method, one rotor shaft inevitably extends out of the compressor housing. Since the compressor cavity is filled with lubricating oil and compressed gas, a strict seal is necessary at the rotor extension shaft. Currently known screw compressors typically use oil seals for this purpose. However, using oil seals to seal the rotor extension shaft is problematic because the rotor shaft rotates at high speeds for extended periods. The oil in contact with the rotor shaft is prone to wear, and if the lubricating oil sinters at high temperatures, this wear can be exacerbated, leading to lubricating oil and gas leakage.

[0003] During operation, both the compressed gas and the motor stator of an oil-injected screw compressor generate a significant amount of heat, necessitating cooling. Common oil-injected screw compressors cool the compressor and motor separately. The compressor's internal cooling system uses lubricating oil injected into the compressor cavity to cool the compressed gas; the motor is cooled using either air or water cooling. This separate cooling of the motor and compressor results in a complex structure and high cost. Utility Model Content

[0004] The main technical problem to be solved by this utility model is to provide an oil-injected screw compressor that reduces costs and has high cooling efficiency.

[0005] To solve the above-mentioned technical problems, this utility model provides an oil-injected screw compressor, comprising: the compressor having a compression chamber formed by a lower housing and an upper housing;

[0006] The compression chamber is equipped with a pair of meshing screw rotors, namely a female rotor and a male rotor; the axes of the female rotor and the male rotor are parallel to each other and rotate in opposite directions; bearings are respectively installed on the rotor shafts of the female rotor and the male rotor.

[0007] The lower housing is provided with an air intake inlet, and the upper housing is provided with an exhaust outlet; the inner wall of the compression chamber has a contour shape that closely matches the female rotor and the male rotor, and when the compressor rotor rotates, the contour separates the air intake inlet and the exhaust outlet.

[0008] It also includes a motor, the motor housing and the upper housing of which are connected by a transition flange; the three-phase power of the motor stator is connected to a terminal block, and the terminal block is sealed to the motor housing by an O-ring;

[0009] Lubricating oil is injected into the compressor through the transition flange, first flows into the motor shell to cool the motor, then is connected to the upper shell of the compressor through the external pipeline, and then is injected into the compression cavity and the bearing on the rotor shaft of the male rotor and the female rotor for cooling and lubrication, and then the lubricating oil and the compressed gas are mixed and discharged through the exhaust outlet.

[0010] In a preferred embodiment: the upper shell is internally provided with an oil return circuit for returning the lubricating oil to the compression cavity.

[0011] In a preferred embodiment: the bottom of the lower shell is provided with a foot for supporting the compressor.

[0012] In a preferred embodiment: the rotor shaft of the male rotor is connected with the driving motor rotor, the motor rotor is outside the motor stator, the motor stator is surrounded by the motor shell, and the motor stator is tightly fitted with the inner wall surface of the motor shell and is fixed to the inner wall surface of the motor shell through the set screw.

[0013] In a preferred embodiment: the rotor shafts of the motor rotor and the male rotor are connected through direct coupling, and the motor rotor and the male rotor are fixed through screws.

[0014] In a preferred embodiment: the motor is a permanent magnet synchronous motor, and the rotor is a permanent magnet, and the rotation magnetic field is generated through the energization of the stator to interact with the permanent magnet on the rotor, so as to promote the synchronous rotation of the rotor along with the rotation of the magnetic field of the stator.

[0015] Compared with the prior art, the technical scheme of the utility model has the following beneficial effects:

[0016] 1. The utility model provides a kind of oil-injected screw compressor, and the compressor is powered on, and permanent magnet motor rotor drives screw male rotor to rotate, and screw female rotor rotates in the direction opposite to screw male rotor, and compressed medium enters compressor from suction inlet, and is fully mixed with the lubricating oil injected into compression cavity, and medium is compressed in compression cavity, and pressure is increased, and then compressed medium and lubricating oil are discharged from exhaust outlet, and enter next stage compressor or system pipeline.It has the advantage of high integration, and motor and compressor head share a cooling system, which not only reduces cost, but also has higher cooling efficiency.

[0017] 2. The utility model provides a kind of oil-injected screw compressor, and cancels oil seal, and compression cavity and motor shell cavity are communicated, which can avoid lubricating oil leakage. DRAWINGS

[0018] Figure 1 It is the top view of the preferred embodiment of the utility model;

[0019] Figure 2 It is Figure 1 It is the sectional view at A-A position;

[0020] Figure 3 for Figure 1 Sectional view at position BB;

[0021] Figure 4 This is an external structural diagram of a preferred embodiment of the present invention. Detailed Implementation

[0022] To make the technical solution and features of this utility model clearer, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only for illustrating this utility model and are not intended to limit the scope of this utility model. After reading this utility model, any modifications of this utility model by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

[0023] refer to Figures 1-4 This embodiment provides an oil-injected screw compressor with a vertical structure. The compressor includes a lower housing 1 and an upper housing 2, which together form a compression chamber 3. The bottom of the lower housing 1 includes three feet 1-1 for supporting the entire compressor.

[0024] Inside the compression chamber 3, there is a pair of screw rotors with intermeshing profiles, namely female rotor 4 and male rotor 5. The axes of female rotor 4 and male rotor 5 are parallel to each other and rotate in opposite directions. In this example, viewed from the direction of machine foot 1-1, female rotor 4 rotates counterclockwise and male rotor 5 rotates clockwise.

[0025] The lower housing 1 is provided with an air intake 1-2, and the upper housing 2 is provided with an exhaust outlet 2-1. The inner wall of the cavity formed by the lower housing 1 and the upper housing 2 has a contour shape that fits tightly with the rotor 4 and the rotor 5. When the compressor rotor rotates, this contour separates the compressor's air intake 1-2 and exhaust outlet 2-1, so that the compressor can compress air and increase pressure when it rotates.

[0026] Bearings are installed on the rotor shafts 4-1, 4-2, 5-1, and 5-2 of the female rotor 4 and the male rotor 5 to bear the axial force, radial force, and the weight of the female rotor 4 and the male rotor 5 themselves generated during compressor operation. The types of bearings are not limited to... Figure 1 As shown.

[0027] The rotor shaft 5-2 of the male rotor 5 is connected to the drive motor rotor 6. Outside the motor rotor is the motor stator 7, and outside the motor stator 7 is the motor housing 8. The motor stator 7 and the motor housing 8 are tightly fitted together and fixed to the inner wall of the motor housing 8 by set screws 9. The motor rotor 6 and the rotor shaft 5-2 are connected by a direct connection and fixed to the rotor 5 by screws. The connection method between the motor rotor 6 and the rotor shaft 5-2 is not limited to this; other connection methods are not excluded in this embodiment.

[0028] This motor is a permanent magnet synchronous motor. The rotor 6 is a permanent magnet. When the stator 7 is energized, a rotating magnetic field is generated, which interacts with the permanent magnet on the rotor 6, causing the rotor 6 to rotate synchronously with the rotation of the magnetic field of the stator 7. The rotation of the motor rotor 6 drives the male rotor 5 to rotate. The female rotor 4 and the male rotor 5 mesh with each other and rotate along with the male rotor 5.

[0029] The motor housing 8 and the upper housing 2 are directly connected together via a transition flange 10, and the compression chamber 3 and the motor housing cavity 8-1 are not sealed to each other. Compared with common oil-injected screw compressors, the compressor in this embodiment eliminates the oil seal structure, avoiding leakage of lubricating oil and gas.

[0030] To prevent leakage in the compression chamber 3 caused by the motor housing cavity 8-1 being connected to the outside, the three-phase power of the stator 7 is connected to the terminal block 11 and is not directly connected to the external power source. The terminal block 11 is sealed to the motor housing 8 by an O-ring.

[0031] In this embodiment, the motor and compressor share a common cooling system. Lubricating oil is injected into the compressor through the transition flange 10, first flowing into the motor housing 8 to cool the motor, then connecting to the compressor upper housing 2 via external pipelines, and then being injected into the compression chamber 3 and the bearings on the rotor shafts 4-2 and 5-2 via internal pipelines for cooling and lubrication. Finally, the lubricating oil and compressed gas mix and enter the next stage compressor or system pipeline through the exhaust outlet 2-1. In particular, the upper housing 2 is equipped with an oil return circuit to return the lubricating oil used to cool and lubricate the bearings on the rotor shafts 4-2 and 5-2 back to the compression chamber 3.

[0032] When the compressor is powered on, the permanent magnet motor rotor 6 drives the screw rotor 5 to rotate. The screw rotor 4 rotates in the opposite direction to the screw rotor 5. The compressed medium enters the compressor from the suction inlet 1-2 and mixes thoroughly with the lubricating oil injected into the compression chamber 3. The medium is compressed in the compression chamber, and the pressure increases. Then the compressed medium and the lubricating oil are discharged together from the exhaust outlet 2-1 and enter the next stage compressor or system pipeline.

[0033] The above is only one specific embodiment of the present utility model, but the design concept of the present utility model is not limited thereto. Any non-substantial modifications made to the present utility model using this concept shall be deemed as an infringement of the protection scope of the present utility model.

Claims

1. An oil-injected screw compressor characterised in that Comprise: The compressor is composed of a lower shell and an upper shell to form a compression cavity; A pair of screw rotors with interlocking profiles are installed inside the compression cavity, namely a female rotor and a male rotor; the axes of the female rotor and the male rotor are parallel to each other and the rotation directions are opposite; bearings are installed on the rotor shafts of the female rotor and the male rotor, respectively; An air inlet is arranged on the lower shell and an air outlet is arranged on the upper shell; the inner wall surface of the compression cavity has a profile shape that closely matches the female rotor and the male rotor, and when the compressor rotors rotate, the profile separates the air inlet and the air outlet; It also includes a motor, the motor shell and the upper shell are connected through a transition flange; the three-phase electricity of the motor stator is connected to the terminal block, and the terminal block seals the motor shell through an O-ring; Lubricating oil is injected into the compressor through the transition flange, first flows into the motor shell to cool the motor, then is connected to the upper shell of the compressor through external pipelines, and then is injected into the compression cavity and the bearings on the rotor shafts of the female rotor and the male rotor for cooling and lubrication. After that, the lubricating oil and the compressed gas are mixed and discharged through the air outlet.

2. An oil-injected screw compressor as claimed in claim 1, characterised in that: An oil return circuit is arranged inside the upper shell to return the lubricating oil to the compression cavity.

3. An oil-injected screw compressor as claimed in claim 1, characterised in that: The bottom of the lower shell is provided with a machine foot for supporting the compressor.

4. An oil-injected screw compressor as claimed in claim 1, characterised in that: The rotor shaft of the male rotor is connected to the motor rotor, the outside of the motor rotor is the motor stator, the periphery of the motor stator is the motor shell, the motor stator closely matches the motor shell, and is fixed to the inner wall surface of the motor shell through a set screw.

5. An oil-injected screw compressor as claimed in claim 4, characterised in that: The rotor shafts of the motor rotor and the male rotor are connected through direct coupling, and the motor rotor and the male rotor are fixed through screws.

6. An oil-injected screw compressor as claimed in claim 5, characterised in that: The motor is a permanent magnet synchronous motor, the rotor is a permanent magnet, and the stator is energized to generate a rotating magnetic field, which interacts with the permanent magnet on the rotor to promote the synchronous rotation of the rotor with the rotation of the stator magnetic field.

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