Segmented reverse rotor structure of oil injection screw compressor

Abstract

The invention discloses a segmented reverse rotor structure of an oil injection screw compressor, comprising: a casing, in which a first-stage compression chamber and a second-stage compression chamber are formed; the first-stage male rotor is rotatably mounted in the first-stage compression cavity, and a first-stage female rotor is rotatably mounted in the first-stage compression cavity; the second-stage male rotor is coaxially connected to the first-stage male rotor and is rotatably mounted in the second-stage compression cavity, a second-stage female rotor is rotatably mounted in the second-stage compression cavity, and the spiral direction of the second-stage male rotor is opposite to that of the first-stage male rotor; the transfer cavity is formed in the shell wall of the machine shell, an air suction port communicating with the first-stage compression cavity is formed in the outer side of the machine shell, a communicating hole channel communicating with the first-stage compression cavity and the transfer cavity is formed in the middle partition plate, and an output port communicating with the second-stage compression cavity and the transfer cavity is formed in the inner side of the machine shell; an exhaust port communicating with the transfer cavity is formed in the outer side of the machine shell. The screw compressor solves the problem that when an existing screw compressor operates, the load of the axial bearing at the end of the rotor is large.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of screw air compressor, in particular to a segmented reverse rotor structure of an oil-injected screw compressor. BACKGROUND

[0002] The existing screw compressor is provided with a cylindrical roller shaft 1' bearing at the suction and exhaust ends of the rotor for bearing the radial force of the rotor. In addition, an angular contact ball bearing 3' is provided at the exhaust end of the rotor 2' for bearing the axial force of the rotor. When a single-stage rotor is running, due to the large pressure at the exhaust end of the rotor, an axial force F towards the suction end of the rotor is generated, which needs to be borne by 1-2 angular contact bearings to prevent the rotor from moving towards the suction end and rubbing against the casing, thereby damaging the compressor. On the other hand, when selecting an angular contact bearing, the axial force generated needs to be calculated according to parameters such as the profile, weight, operating pressure and rotational speed of the rotor, and the corresponding size of the bearing needs to be matched. SUMMARY

[0003] In order to overcome the defects of the prior art, the present application provides a segmented reverse rotor structure of an oil-injected screw compressor to solve the problem of large load of the axial bearing at the end of the rotor of the existing screw compressor when the rotor is running.

[0004] To achieve the above-mentioned purpose, a segmented reverse rotor structure of an oil-injected screw compressor is provided, comprising: a casing having opposite first and second ends, a middle part of the casing being formed with a partition plate, the partition plate being provided with a through hole, a first-stage compression chamber being formed between one side of the partition plate and the first end of the casing, and a second-stage compression chamber being formed between the other side of the partition plate and the second end of the casing; a first-stage male rotor rotatably installed in the first-stage compression chamber, and a first-stage female rotor rotatably installed in the first-stage compression chamber and engaged with the first-stage male rotor; a second-stage male rotor rotatably installed in the second-stage compression chamber, the second-stage male rotor being coaxially connected to the first-stage male rotor through the through hole, a second-stage female rotor rotatably installed in the second-stage compression chamber and engaged with the second-stage male rotor, the helical direction of the second-stage male rotor being opposite to that of the first-stage male rotor, the first-stage male rotor and the second-stage male rotor rotating simultaneously and generating two opposite axial forces when compressing fluid; A transfer chamber is formed in the shell wall of the second end of the casing, the outer side of the first end of the casing is formed with an air inlet connected to the primary compression chamber, the partition plate is formed with a communication channel connected to the primary compression chamber and the transfer chamber, the inner side of the second end of the casing is formed with an outlet connected to the secondary compression chamber and the transfer chamber, and the outer side of the second end of the casing is provided with an exhaust port connected to the transfer chamber.

[0005] Further, the primary male rotor and the primary female rotor compress fluid to form intermediate stage compressed gas, and the pressure value of the intermediate stage compressed gas is 1 / 3 of the exhaust pressure value of the exhaust port.

[0006] Further, the two axial forces are equal in size.

[0007] Further, the transfer chamber is arranged along the circumferential direction of the casing, and the outlet and the communication channel are arranged on opposite sides of the casing, respectively.

[0008] Further, the casing comprises: The casing has an open end and a closed end, the closed end is formed with a first shaft hole, one end of the primary male rotor is rotatably arranged in the first shaft hole through a bearing, and the partition plate is mounted in the open end to close the open end. A bearing seat is detachably mounted outside the open end, the bearing seat is formed with a second shaft hole, one end of the secondary male rotor is rotatably mounted in the second shaft hole through a bearing, and the side of the bearing seat facing the casing forms the transfer chamber.

[0009] Further, the outer end of the second shaft hole is detachably mounted with an end cover.

[0010] The beneficial effects of the present application are that the segmented reverse rotor structure of the oil-injected screw compressor reduces the axial force of the rotor to the air inlet end when the compressor is running, reduces the load of the axial bearing, and improves the service life of the bearing. On the other hand, when the segmented reverse rotor structure of the oil-injected screw compressor is adopted, the compressor can select smaller size bearings, reducing the cost of parts. BRIEF DESCRIPTION OF DRAWINGS

[0011] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings: Figure 1 It is a schematic view of the structure of the prior art oil-injected screw compressor.

[0012] Figure 2 It is a schematic view of the segmented reverse rotor structure of the oil-injected screw compressor of the embodiment of the present application.

[0013] Figure 3 A sectional view of the segmented reverse rotor structure of the oil-injected screw compressor according to an embodiment of the present application.

[0014] Figure 4 A sectional view of the segmented reverse rotor structure of the oil-injected screw compressor according to an embodiment of the present application. Figure 3

[0015] Figure 5 A perspective view of the rotor according to an embodiment of the present application.

[0016] Reference Signs: A casing 1, a partition plate 11, a shell 12, a bearing seat 13, an end cover 14, a primary compression chamber A, a secondary compression chamber B, an air inlet a, an air outlet b, a communication channel c, an output port d; A primary male rotor 2, a primary female rotor 21; A secondary male rotor 3, a secondary female rotor 31; A middle transfer chamber 4; Axial forces F1, F2. DETAILED DESCRIPTION

[0017] The application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related application, and are not a limitation on the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description.

[0018] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0019] Referring to Figures 2 to 5 The present application provides a segmented reverse rotor structure of an oil-injected screw compressor, comprising: a casing 1, a primary male rotor 2, a secondary male rotor 3, and a middle transfer chamber 4.

[0020] In the present embodiment, the casing 1 is in a cylindrical shape. The casing 1 has opposite first and second ends. A middle portion of the casing 1 is formed with a partition plate 11. The partition plate 11 is provided with a through hole. The partition plate divides the inner cavity of the casing into two parts, so that a primary compression chamber A is formed between one side of the partition plate 11 and the first end of the casing 1, and a secondary compression chamber B is formed between the other side of the partition plate 11 and the second end of the casing 1.

[0021] The primary male rotor 2 is rotatably installed in the primary compression chamber A. A primary female rotor 21 is rotatably installed in the primary compression chamber A. The primary female rotor 21 is engaged with the primary male rotor 2.

[0022] ​In this embodiment, the primary male rotor and the primary female rotor mesh or interlock to perform primary compression on the fluid in the primary compression chamber to generate intermediate compressed gas.

[0023] The secondary male rotor 3 is rotatably mounted in the secondary compression chamber B. The secondary male rotor 3 is coaxially connected to the primary male rotor 2 via a perforation. The secondary female rotor 31 is rotatably mounted in the secondary compression chamber B. The secondary female rotor 31 meshes with the secondary male rotor 3. The secondary female rotor 31 is coaxially arranged with the primary female rotor 21.

[0024] In this embodiment, the secondary male rotor and the secondary female rotor mesh or interlock to perform secondary compression on the intermediate compressed gas in the secondary compression chamber to generate compressed gas.

[0025] The helical direction of the secondary male rotor 3 is opposite to that of the primary male rotor 2. When compressing the fluid, the primary male rotor 2 and the secondary male rotor 3 rotate simultaneously and generate two opposing axial forces (i.e., axial force F1 and axial force F2).

[0026] In a preferred embodiment, the primary male rotor 2 and the primary female rotor 21 compress the fluid to form an intermediate stage compressed gas. The pressure value of the intermediate stage compressed gas is 1 / 3 of the exhaust pressure value of the exhaust port b.

[0027] In this embodiment, the two axial forces are equal in magnitude but opposite in direction, thus canceling each other out.

[0028] A transfer chamber 4 is formed within the shell wall at the second end of the housing 1. An intake port a is formed on the outer side of the first end of the housing 1, communicating with the primary compression chamber A. A connecting channel c is formed in the partition plate 11, communicating with the primary compression chamber A and the transfer chamber 4. An output port d is formed on the inner side of the second end of the housing 1, communicating with the secondary compression chamber B and the transfer chamber 4. An exhaust port b is provided on the outer side of the second end of the housing 1, communicating with the transfer chamber 4.

[0029] In a preferred embodiment, the transfer chamber 4 is arranged along the circumferential direction of the housing 1. The output port d and the connecting channel c are respectively located on opposite sides of the housing 1.

[0030] In this embodiment, the primary male rotor and the secondary male rotor are integrally formed, and their rotor shafts are coaxially connected together.

[0031] In this embodiment, the housing is a detachable structure. Specifically, the housing 1 includes a casing 12 and a bearing seat 13.

[0032] The housing 12 has an open end and a closed end. A first shaft hole is formed at the closed end of the housing 12. In this embodiment, one end of the primary male rotor 2 is rotatably inserted into the first shaft hole formed at the closed end of the housing 12 via a bearing. A partition plate 11 is installed inside the open end to close it. The other end of the primary male rotor is rotatably inserted through a hole in the partition plate and connected to the other end of the secondary male rotor.

[0033] The bearing housing 13 is detachably mounted outside the open end. The bearing housing is cover-shaped. The cover of the bearing housing is detachably mounted to the open end of the housing by bolts. The intermediate partition and the bearing housing enclose a secondary compression chamber. The bearing housing 13 has a second shaft hole. The second shaft hole is located at the top of the cover of the bearing housing. One end of the secondary male rotor 3 is rotatably mounted in the second shaft hole by bearings (radial bearings and axial bearings). The side of the bearing housing 13 facing the housing 12 forms a transfer chamber 4.

[0034] Specifically, a transfer chamber is formed within the side wall of the bearing housing. After the bearing housing is installed on the end face of the open end of the housing, the end face of the open end closes the transfer chamber.

[0035] In some embodiments, an end cap 14 is detachably mounted on the outer port of the second shaft hole to improve the airtightness and safety of the housing.

[0036] The segmented reverse rotor structure of the oil-injected screw compressor of this invention divides the rotor of a traditional compressor into a primary rotor and a secondary rotor. The two rotors are separated by a partition to prevent air drawn into the primary compression chamber from directly entering the secondary compression chamber. After the primary rotor rotates, it draws in air from outside the casing through the intake port. In the primary compression chamber, air is compressed by the primary rotor to one-third of the compressor's discharge pressure, forming an intermediate-stage compressed gas. This intermediate-stage compressed gas is discharged into the intermediate transfer chamber through the connecting passage of the partition. It is then discharged into the secondary compression chamber through the output port. The helical direction of the secondary rotor is opposite to that of the primary rotor, so the intermediate-stage compressed gas is drawn in from the left side of the secondary rotor and discharged from the right side after compression. In this embodiment, a diversion chamber connects the intermediate transfer chamber and the exhaust port within the casing wall. The exhaust port is located on the left side of the secondary rotor. The exhaust port and the intermediate transfer chamber are located on opposite sides of the casing. When the compressor is running (i.e., when the first-stage rotor and the second-stage rotor are rotating), the exhaust directions of the first-stage rotor and the second-stage rotor are opposite. The axial force F1 of the first-stage rotor is to the right, and the axial force F2 of the second-stage rotor is to the left.

[0037] In the segmented reverse rotor structure of the oil-injected screw compressor of the present invention, the discharge pressure of the first stage is lower than that of the single stage, resulting in a smaller axial force towards the suction end. The opposite axial force generated by the second stage rotor cancels it out, so the axial force of the entire rotor is much smaller, effectively reducing the load on the axial bearing, extending the service life of the bearing, and reducing maintenance costs.

[0038] The segmented reverse rotor structure of the oil-injected screw compressor of the present invention reduces the axial force of the rotor towards the suction end during compressor operation, thereby reducing the load on the axial bearing and improving bearing life. Furthermore, by employing the segmented reverse rotor structure of the oil-injected screw compressor of the present invention, smaller bearings can be selected, reducing component costs.

[0039] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A segmented reverse-rotor structure of an oil-injected screw compressor, characterized by, The utility model relates to a kind of compressor, comprising: Casing, the casing has opposite first end and second end, the middle part of the casing is formed with partition, the partition is opened with through hole, the one side of the partition and the first end of the casing form primary compression cavity, the other side of the partition and the second end of the casing form secondary compression cavity; Primary male rotor, rotatably mounted in the primary compression cavity, the primary compression cavity is rotatably mounted with primary female rotor engaged with the primary male rotor; Secondary male rotor, rotatably mounted in the secondary compression cavity, the secondary male rotor is coaxially connected to the primary male rotor by the through hole, the secondary compression cavity is rotatably mounted with secondary female rotor engaged with the secondary male rotor, the helical direction of the secondary male rotor is opposite to the helical direction of the primary male rotor, when compressing fluid, the primary male rotor and the secondary male rotor rotate simultaneously and generate two axial forces in opposite directions respectively; Intermediate transfer chamber, formed in the shell wall of the second end of the casing, the outside of the first end of the casing is formed with suction port communicated with the primary compression cavity, the partition is formed with communication hole communicated with the primary compression cavity and the intermediate transfer chamber, the inside of the second end of the casing is formed with output port communicated with the secondary compression cavity and the intermediate transfer chamber, the outside of the second end of the casing is opened with exhaust port communicated with the intermediate transfer chamber.

2. The segmented reverse-rotor structure of an oil-injected screw compressor according to claim 1, characterized in that, The primary male rotor and the primary female rotor compress fluid to form intermediate stage compressed gas, the pressure value of the intermediate stage compressed gas is 1 / 3 of the exhaust pressure value of the exhaust port.

3. The segmented reverse-rotor structure of an oil-injected screw compressor according to claim 2, characterized in that, The two axial forces are equal in size.

4. The segmented reverse-rotor structure of an oil-injected screw compressor according to claim 1, characterized in that, The intermediate transfer chamber is arranged along the circumferential direction of the casing, and the output port and the communication hole are arranged on opposite sides of the casing respectively.

5. The segmented reverse-rotor structure of an oil-injected screw compressor according to claim 1, characterized in that, The casing comprises: Shell box, the shell box has an open end and a closed end, the closed end is formed with a first shaft hole, one end of the primary male rotor is rotatably threaded in the first shaft hole through a bearing, and the partition is installed in the open end to close the open end; Bearing seat, detachably mounted outside the open end, the bearing seat is formed with a second shaft hole, one end of the secondary male rotor is rotatably mounted in the second shaft hole through a bearing, and the side of the bearing seat facing the shell box forms the intermediate transfer chamber.

6. The segmented reverse-rotor structure of an oil-injected screw compressor according to claim 5, characterized in that, The outer port of the second shaft hole is detachably mounted with an end cover.

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