Structure for balancing axial force of male rotor of screw compressor

Abstract

The utility model relates to a structure for balancing the axial force of a male rotor of a screw compressor, which comprises an exhaust bearing seat, an angular contact bearing is arranged in the exhaust bearing seat, and a balance piston is arranged between a male rotor journal and the angular contact bearing; the side, close to the male rotor journal, of the balance piston is connected with an exhaust high-pressure oil inlet, and the side, close to the angular contact bearing, of the balance piston is connected with suction low-pressure gas. The balance piston is additionally arranged at the exhaust end of the male rotor, exhaust high-pressure oil is introduced into the front face of the balance piston, suction low-pressure gas is communicated with the reverse face of the balance piston, thrust opposite to the axial force direction of the male rotor is generated through the pressure difference of the two faces of the balance piston, and therefore the effect of counteracting the axial force of the male rotor is achieved. The axial force in the operation process of the male rotor is reduced, so that the service life of the angular contact bearing at the exhaust end of the male rotor is prolonged, the operation range of the screw compressor is expanded, and the reliability of the screw compressor is improved.

Description

Technical Field

[0001] The utility model relates to a mechanical structure, in particular to a structure for balancing the axial force of a male rotor of a screw compressor. Background Art

[0002] Screw compressors have the characteristics of smooth operation, strong impact resistance, low vibration and noise, and few wearing parts. They are widely used in compressing gases such as refrigerants and air. Twin-screw compressors consist of a pair of yin and yang rotors assembled in parallel in the shell. Generally, the main driving side is the yang rotor and the driven side is the yin rotor. The yang rotor drives the yin rotor to rotate, realizing the suction, compression, and exhaust processes.

[0003] The male rotor generates a huge axial force during the compression process, and as the suction and exhaust pressure difference of the screw compressor increases, the axial force of the male rotor increases. The direction of the axial force is from the exhaust end of the screw compressor to the suction end. Currently, the axial force of the male rotor is offset by installing multiple angular contact bearings at the exhaust end of the male rotor. Although the axial force of the male rotor of the screw compressor can be offset by installing multiple angular contact bearings, the continuous development of heat pump and refrigeration screw compressors requires the pursuit of higher condensing temperatures and lower evaporation temperatures, resulting in the continuous expansion of the operating range of the screw compressor. The suction and exhaust pressure difference of the screw compressor increases, resulting in an increase in the axial force, which affects the life of the angular contact bearing at the exhaust end of the male rotor and causes the bearing to fail prematurely. Utility Model Content

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present invention proposes a structure for balancing the axial force of a male rotor of a screw compressor.

[0005] The technical solution adopted by the utility model to solve the technical problem is: a structure for balancing the axial force of the male rotor of a screw compressor, comprising an exhaust bearing seat, on which the male rotor and the female rotor are respectively mounted through the male rotor journal and the female rotor journal;

[0006] An angular contact bearing is further provided in the exhaust bearing seat, and a balancing piston is provided between the male rotor journal and the angular contact bearing, with one side of the balancing piston in contact with the end face of the male rotor journal and the other side of the balancing piston in contact with the end face of the angular contact bearing;

[0007] The side of the balancing piston close to the male rotor journal is connected to an exhaust high-pressure oil inlet, and the side of the balancing piston close to the angular contact bearing is connected to an intake low-pressure gas.

[0008] In a preferred embodiment of the present invention, a journal seal is provided between the outer wall of the male rotor journal and the inner wall of the exhaust bearing seat; the inner ring of the journal seal facing the male rotor journal is serrated.

[0009] In a preferred embodiment of the present invention, the fitting clearance between the journal seal and the male rotor journal is 0.1-0.2 mm.

[0010] In a preferred embodiment of the present invention, the journal seal is a plurality of tooth groove sealing units connected in series, and the top angle of the tooth groove on each tooth groove sealing unit is 30-60°.

[0011] In a preferred embodiment of the present invention, the number of the tooth groove sealing units is 5-10.

[0012] In a preferred embodiment of the present invention, an exhaust high-pressure oil chamber is provided on the side of the balancing piston close to the male rotor journal, and an intake low-pressure chamber is provided on the side of the balancing piston close to the angular contact bearing.

[0013] The beneficial effects of the present invention are as follows: the present invention provides a structure for balancing the axial force of the male rotor of a screw compressor, adds a balancing piston to the exhaust end of the male rotor, introduces a path of exhaust high-pressure oil at the front of the balancing piston, and connects the back side of the balancing piston to the intake low-pressure gas, and generates a thrust in the opposite direction of the axial force of the male rotor through the pressure difference on both sides of the balancing piston, thereby achieving the effect of offsetting the axial force of the male rotor, reducing the axial force of the male rotor during operation, thereby increasing the service life of the angular contact bearing at the exhaust end of the male rotor, expanding the operating range of the screw compressor, and improving the reliability of the screw compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the utility model;

[0015] Figure 2 It is a schematic diagram of the internal structure of the utility model;

[0016] Figure 3 This is a schematic diagram of the exhaust high-pressure oil inlet structure of the utility model;

[0017] Figure 4 This is a schematic diagram of the pressure at both ends of the balancing piston of the utility model;

[0018] Figure 5 This is a schematic diagram of the structure of the journal seal of the utility model;

[0019] In the figure: exhaust bearing seat 1; male rotor journal 2; female rotor journal 3; male rotor 4; female rotor 5; angular contact bearing 6; balance piston 7; journal seal 8; tooth groove seal unit 801; exhaust high-pressure oil chamber 9; intake low-pressure chamber 10; exhaust high-pressure oil inlet 11. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0022] like Figures 1 to 5 The structure shown is a structure for balancing the axial force of the male rotor of a screw compressor, including an exhaust bearing seat 1, on which a male rotor 4 and a female rotor 5 are mounted respectively via a male rotor journal 2 and a female rotor journal 3. The male rotor and the female rotor are respectively mounted on the exhaust bearing seat, and the male rotor 4 drives the female rotor 5 to rotate, realizing the processes of suction, compression, and exhaust.

[0023] An angular contact bearing 6 is further provided in the exhaust bearing seat 1, and a balancing piston 7 is provided between the male rotor journal 2 and the angular contact bearing 6, with one side of the balancing piston 7 in contact with the end face of the male rotor journal 2, and the other side of the balancing piston 7 in contact with the end face of the angular contact bearing 6;

[0024] The side of the balancing piston 7 close to the male rotor journal 2 is connected to the exhaust high-pressure oil inlet 11, and the side of the balancing piston 7 close to the angular contact bearing 6 is connected to the intake low-pressure gas;

[0025] The side of the balancing piston 7 close to the male rotor journal is the front side, and the front side is connected to an exhaust high-pressure oil inlet 11. Exhaust high-pressure oil is discharged from the exhaust high-pressure oil inlet 11 to the front side of the balancing piston 7, that is, a path of exhaust high-pressure oil is introduced to the front side of the balancing piston 7, and the back side of the balancing piston is connected to the intake low-pressure gas. The thrust is generated by the pressure difference on both sides of the balancing piston. The direction of the thrust is from left to right, and the axial force of the male rotor is from right to left. Since the thrust of the balancing piston and the axial force of the rotor are in opposite directions, they can offset each other, thereby achieving the effect of offsetting the axial force of the male rotor.

[0026] As a preferred embodiment, a journal seal 8 is provided between the outer wall of the male rotor journal 2 and the inner wall of the exhaust bearing seat 1 in the present application; the journal seal 8 improves the sealing performance of the exhaust high-pressure oil on the front of the balancing piston, and the inner ring of the journal seal 8 facing the male rotor journal 2 is serrated, achieving the effect of a labyrinth seal, which can prevent the exhaust high-pressure oil on the front of the balancing piston from leaking to the male rotor journal, thereby ensuring the pressure stability of the exhaust high-pressure chamber. Preferably, the balancing piston 7 in the present application is provided with an exhaust high-pressure oil chamber 9 on the side close to the male rotor journal 2, and an intake low-pressure chamber 10 is provided on the side close to the angular contact bearing 6 of the balancing piston 7, and the intake low-pressure chamber 10 is connected to the intake low-pressure gas. That is, the provision of the journal seal 8 is conducive to improving the sealing performance of the exhaust high-pressure oil chamber 9 on the front of the balancing piston, thereby ensuring the pressure stability in the exhaust high-pressure oil chamber on the front of the balancing piston, and generating a larger thrust to offset the axial force of the male rotor.

[0027] As a preferred embodiment, the clearance between the journal seal 8 and the male rotor journal 2 is 0.1-0.2mm. More preferably, the journal seal 8 comprises multiple tooth-slot seal units 801 connected in series, with 5-10 tooth-slot seal units 801. The tooth slots 802 of the multiple tooth-slot seal units 801 in this application are machined on the exhaust bearing seat 1, and the machined positions align with the male rotor journal. To ensure the rotational motion of the male rotor and the sealing effect on the exhaust high-pressure oil chamber 9, the clearance between the tooth-slot seal unit and the male rotor journal 2 is 0.1-0.2mm, the top angle of the tooth slot on the tooth-slot seal unit is 30-60°, and the number of tooth-slot seal units connected in series is 5-10. The multiple tooth-slot seal units form a labyrinth seal, which can prevent the exhaust high-pressure oil from the front of the balance piston from leaking into the male rotor journal, ensuring the pressure stability of the exhaust high-pressure chamber. The exhaust high-pressure oil can only leak to the back of the balance piston into the intake low-pressure chamber 10, ensuring the stability of the balance piston thrust and effectively offsetting the axial force of the male rotor.

[0028] The utility model provides a structure for balancing the axial force of the male rotor of a screw compressor. A balancing piston is added to the exhaust end of the male rotor, and a path of exhaust high-pressure oil is introduced at the front of the balancing piston. The back side of the balancing piston is connected to the intake low-pressure gas. The pressure difference between the two sides of the balancing piston generates a thrust in the opposite direction to the axial force of the male rotor, thereby achieving the effect of offsetting the axial force of the male rotor, reducing the axial force of the male rotor during operation, thereby increasing the service life of the angular contact bearing at the exhaust end of the male rotor, expanding the operating range of the screw compressor, and improving the reliability of the screw compressor.

[0029] Throughout this specification, references to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" indicate that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0030] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A structure for balancing the axial force of the male rotor of a screw compressor, characterized in that: It comprises an exhaust bearing seat (1), on which a male rotor (4) and a female rotor (5) are mounted respectively via a male rotor journal (2) and a female rotor journal (3); An angular contact bearing (6) is further provided in the exhaust bearing seat (1), and a balancing piston (7) is provided between the male rotor journal (2) and the angular contact bearing (6), with one side of the balancing piston (7) in contact with the end face of the male rotor journal (2), and the other side of the balancing piston (7) in contact with the end face of the angular contact bearing (6); The side of the balancing piston (7) close to the male rotor journal (2) is connected to an exhaust high-pressure oil inlet (11), and the side of the balancing piston (7) close to the angular contact bearing (6) is connected to an intake low-pressure gas.

2. The structure for balancing the axial force of the male rotor of a screw compressor according to claim 1, characterized in that: A journal seal (8) is provided between the outer wall of the male rotor journal (2) and the inner wall of the exhaust bearing seat (1); the inner ring of the journal seal (8) facing the male rotor journal (2) is serrated.

3. The structure for balancing the axial force of the male rotor of a screw compressor according to claim 2, characterized in that: The fitting clearance between the journal seal (8) and the male rotor journal (2) is 0.1-0.2 mm.

4. The structure for balancing the axial force of the male rotor of a screw compressor according to claim 2, characterized in that: The journal seal (8) comprises a plurality of tooth groove seal units (801) connected in series, and the top angle of the tooth groove (802) on each tooth groove seal unit (801) is 30-60°.

5. The structure for balancing the axial force of the male rotor of a screw compressor according to claim 4, characterized in that: The number of the tooth groove sealing units (801) is 5-10.

6. The structure for balancing the axial force of the male rotor of a screw compressor according to any one of claims 1 to 5, characterized in that: An exhaust high-pressure oil chamber (9) is provided on the side of the balancing piston (7) close to the male rotor journal (2), and an intake low-pressure chamber (10) is provided on the side of the balancing piston (7) close to the angular contact bearing (6).

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