Balancing force adjustment structure for balancing pistons in screw compressors

Abstract

This utility model relates to a balancing force adjustment structure for a balancing piston in a screw compressor. Its features include a rotor on the screw compressor and a balancing piston fitted onto the rotor. The balancing piston includes a balancing end cap and a balancing support, both fitted onto the rotor and used to push against the stepped shaft end face of the rotor. An oil chamber is provided between the balancing end cap and the balancing support. The balancing support is axially fixed to the casing of the screw compressor. The balancing end cap is axially movable relative to the rotor to push against the stepped shaft end face of the rotor. The balancing support has an oil passage that communicates with the oil chamber and an external high-pressure oil circuit. This utility model's balancing force adjustment structure for a balancing piston in a screw compressor is rationally designed and facilitates the adjustment of the balancing force to meet the rotor's force balance requirements.

Description

Technical Field

[0001] This utility model relates to the field of screw compressor technology, and in particular to a balancing force adjustment structure for a balancing piston applied to a screw compressor. Background Technology

[0002] A screw compressor is a positive displacement compressor that compresses gas by continuously rotating a pair of meshing helical rotors (male and female rotors) within a casing, thereby continuously reducing the inter-tooth volume. A single-unit two-stage screw compressor is a type of screw compressor that divides the compression process into two stages: a primary compression process and a secondary compression process. Compared to a single-unit single-stage screw compressor, a single-unit two-stage screw compressor has higher operating efficiency.

[0003] In the existing technology, the second stage discharge pressure of a single-unit bipolar screw compressor is relatively large, which makes the pressure difference between the first stage intake pressure and the second stage discharge pressure large. When the compressor is working, the rotor is subjected to an axial force (collectively referred to as the positive force, and the reverse force mentioned below is the opposite axial force) and a radial force from the exhaust end to the intake end. In order to counteract the positive force of the rotor, bearings are usually arranged to bear the axial force.

[0004] However, since the bearing is rigid (i.e. the reverse force is constant), relying solely on the bearing to bear the axial force cannot achieve flexible bearing of the axial force; furthermore, it is impossible to properly adjust the reverse force and achieve a balance between the positive and reverse forces. An insufficient balancing force cannot play a balancing role, while an excessive balancing force may cause the rotor exhaust end face to collide and scratch with the inner end face of the compressor housing. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of this utility model is to provide a balancing force adjustment structure for a balancing piston of a screw compressor. The structure is reasonably designed and is conducive to adjusting the balancing force to meet the force balance requirements of the rotor.

[0006] This utility model relates to a balancing force adjustment structure for a balancing piston in a screw compressor. Its features include: a rotor on the screw compressor and a balancing piston fitted onto the rotor; the balancing piston includes a balancing end cap and a balancing support, both fitted onto the rotor and used to push against the stepped shaft end face of the rotor; an oil chamber is provided between the balancing end cap and the balancing support; the balancing support is axially fixed to the casing of the screw compressor; the balancing end cap is axially movable relative to the rotor to push against the stepped shaft end face of the rotor; and the balancing support has an oil passage that connects to the oil chamber and an external high-pressure oil circuit.

[0007] Preferably, the portion of the balance support that contacts the rotor is provided with a first recessed groove that communicates with the oil chamber, and a first sealing element is provided inside the first recessed groove.

[0008] Preferably, the portion of the balance end cap that contacts the balance support is provided with a second recessed groove that communicates with the oil cavity, and a second sealing element is provided inside the second recessed groove.

[0009] Preferably, a bearing is provided between the balance end cover and the rotor stepped shaft end face, with the first side of the bearing abutting against the rotor stepped shaft end face and the end of the balance end cover abutting against the second side of the bearing.

[0010] Preferably, a retaining ring is provided between the end of the aforementioned balance end cap and the second side of the bearing.

[0011] Preferably, the aforementioned balance end cap can be replaced to adjust and change the force-bearing area between the balance end cap and the oil cavity.

[0012] Preferably, the aforementioned balance end cap or balance support is provided with a threaded groove communicating with the oil passage. The bottom end of the threaded groove is communicating with the oil passage, and the opening of the threaded groove is communicating with the outside. A steel ball is provided at the bottom of the threaded groove, and a screw plug is screwed into the opening of the threaded groove. A compression spring is installed between the steel ball and the screw plug.

[0013] The working principle of this utility model, applied to the balancing force adjustment structure of the balance piston in a screw compressor, involves connecting to an external high-pressure oil circuit via an oil passage. High-pressure oil enters the oil chamber through the oil passage, and the increased pressure in the oil chamber pushes against the balance end cover and rotor to counteract the positive force, achieving a balance between the positive and negative forces. Furthermore, the magnitude of the negative force can be adjusted by regulating the pressure of the high-pressure oil, further achieving a balance between the positive and negative forces. Alternatively, the balance end cover can be replaced to change the force-bearing area between it and the oil chamber, thereby adjusting the negative force and achieving a balance between the positive and negative forces. Alternatively, a safety valve connected to the oil chamber and oil passage can be installed to regulate the negative force and achieve a balance between the positive and negative forces. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of one embodiment of the present invention;

[0015] Figure 2 yes Figure 1 A partial view;

[0016] Figure 3 This is a cross-sectional view of another embodiment of the present invention;

[0017] Figure 4 yes Figure 3 A magnified view of a portion of the image. Detailed Implementation

[0018] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] In the description of this utility model, it should be noted that the terms "middle," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] This utility model relates to a balancing force adjustment structure for a screw compressor's balancing piston. The structure includes a rotor 1 on the screw compressor (i.e., the casing) and a balancing piston 2 fitted onto the rotor. The balancing piston 2 includes a balancing end cover 4 and a balancing support 5, both fitted onto the rotor and used to push against the stepped shaft end face 3 of the rotor. An oil chamber 6 is provided between the balancing end cover and the balancing support. The balancing support 5 is axially fixed relative to the rotor (it can be locked by screws passing through the balancing support 5 and the casing). The balancing end cover 4 is axially movable relative to the rotor (i.e., the balancing end cover 4...). The balance support 5 is equipped with an oil passage 7 that can communicate with the oil chamber and the external high-pressure oil circuit. After high-pressure oil is introduced into the external high-pressure oil circuit, the high-pressure oil enters the oil chamber through the oil passage and can push against the balance end cover 4, so that the balance end cover 4 has a tendency to move axially towards the rotor stepped shaft end face 3. Thus, the rotor is pushed against the rotor through the rotor stepped shaft end face 3, realizing the cancellation of the positive force and the balance of the reverse force and the positive force. Furthermore, the magnitude of the reverse force can be adjusted by adjusting the pressure of the high-pressure oil, further realizing the balance of the reverse force and the positive force.

[0021] Another way to adjust the magnitude of the reverse force (balancing force) is to change the force-bearing area between the balance end cap and the oil cavity (i.e., the balance end cap can be replaced with a balance end cap that has a different force-bearing area than the oil cavity), thereby changing the effective force-bearing area and thus adjusting the magnitude of the balancing force.

[0022] Another way to adjust the magnitude of the reverse force (balancing force) is as follows: The balance end cap or balance support is provided with a threaded groove 8 that communicates with the oil passage (preferably the balance end cap is provided with a threaded groove 8 that communicates with the oil passage). The bottom end of the threaded groove communicates with the oil passage, and the opening of the threaded groove communicates with the outside. A steel ball 9 is provided at the bottom of the threaded groove, and a screw plug 10 (which can be an internal hexagonal screw plug) is screwed into the opening of the threaded groove. A compression spring 11 is installed between the steel ball and the screw plug. High-pressure oil is injected into the oil chamber along the oil passage. If the pressure provided by the high-pressure oil does not exceed the specified value, the steel ball closes the oil port (i.e., the opening where the bottom end of the threaded groove communicates with the oil passage). If the pressure provided by the high-pressure oil exceeds the specified value, the high-pressure oil pushes the steel ball to open the oil port, and the high-pressure oil is discharged from the balance piston to prevent the pressure from continuing to rise. Since the pressure is limited, the balancing force is limited and balanced.

[0023] To improve the sealing performance of the oil cavity, a first recessed groove communicating with the oil cavity is provided at the part of the balance support that contacts the rotor, and a first sealing element 11 is provided in the first recessed groove; a second recessed groove communicating with the oil cavity is provided at the part of the balance end cover that contacts the balance support, and a second sealing element 12 is provided in the second recessed groove.

[0024] A bearing 13 is provided between the balance end cover and the end face of the rotor stepped shaft. The first side of the bearing abuts against the end face of the rotor stepped shaft, and the end of the balance end cover abuts against the second side of the bearing. Furthermore, a retaining ring 14 is provided between the end of the balance end cover and the second side of the bearing.

[0025] The working principle of this utility model, applied to the balancing force adjustment structure of the balance piston in a screw compressor, involves connecting to an external high-pressure oil circuit via an oil passage. High-pressure oil enters the oil chamber through the oil passage, and the increased pressure in the oil chamber pushes against the balance end cover and rotor to counteract the positive force, achieving a balance between the positive and negative forces. Furthermore, the magnitude of the negative force can be adjusted by regulating the pressure of the high-pressure oil, further achieving a balance between the positive and negative forces. Alternatively, the balance end cover can be replaced to change the force-bearing area between it and the oil chamber, thereby adjusting the negative force and achieving a balance between the positive and negative forces. Alternatively, a safety valve connected to the oil chamber and oil passage can be installed to regulate the negative force and achieve a balance between the positive and negative forces.

[0026] The beneficial effects of this utility model are: it can reasonably adjust the balancing force provided by the balancing piston to meet the force balance requirements of the rotor, avoiding the problem that too small a balancing force cannot meet the balance requirements, or that too large a balancing force causes the rotor end face to collide and scratch with the inner end face of the compressor housing; the structure is simple and compact and can adapt to different working conditions.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A balancing force adjustment structure for a balancing piston applied in a screw compressor, characterized in that: The compressor includes a rotor on a screw compressor and a balance piston fitted on the rotor. The balance piston includes a balance end cover and a balance support, both fitted on the rotor and used to push against the stepped shaft end face of the rotor. An oil chamber is provided between the balance end cover and the balance support. The balance support is axially fixed to the casing of the screw compressor. The balance end cover is axially movable relative to the rotor to push against the stepped shaft end face of the rotor. The balance support is provided with an oil passage that can communicate with the oil chamber and the external high-pressure oil circuit.

2. The balancing force adjustment structure for a balancing piston applied to a screw compressor according to claim 1, characterized in that: The part of the balance support that contacts the rotor is provided with a first recessed groove that communicates with the oil chamber, and a first sealing element is inserted into the first recessed groove.

3. The balancing force adjustment structure for a balancing piston applied to a screw compressor according to claim 1 or 2, characterized in that: The portion of the balance end cap that contacts the balance support is provided with a second recessed groove that communicates with the oil cavity, and a second sealing element is inserted into the second recessed groove.

4. The balancing force adjustment structure for a balancing piston applied to a screw compressor according to claim 1, characterized in that: A bearing is provided between the balance end cover and the rotor stepped shaft end face. The first side of the bearing abuts against the rotor stepped shaft end face, and the end of the balance end cover abuts against the second side of the bearing.

5. The balancing force adjustment structure for a balancing piston applied to a screw compressor according to claim 4, characterized in that: A retaining ring is provided between the end of the balance end cap and the second side of the bearing.

6. The balancing force adjustment structure for a balancing piston applied to a screw compressor according to claim 1, characterized in that: The balance end cap can be replaced to adjust the force-bearing area between the balance end cap and the oil chamber.

7. The balancing force adjustment structure for a balancing piston applied to a screw compressor according to claim 1, characterized in that: The balance end cap or balance support is provided with a threaded groove that communicates with the oil passage. The bottom end of the threaded groove is connected to the oil passage, and the opening of the threaded groove is connected to the outside. A steel ball is provided at the bottom of the threaded groove, and a screw plug is screwed into the opening of the threaded groove. A compression spring is installed between the steel ball and the screw plug.

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