Compressor capacity adjusting structure

Abstract

The utility model provides a compressor capacity adjusting structure. The compressor capacity adjusting structure comprises a machine shell; the electromagnetic valve is mounted on the machine shell; the bearing seat is installed on the machine shell, and an oil hydraulic cylinder is formed in the bearing seat; the sliding block is located in the sliding groove of the stroke in the machine shell; one end of the piston rod is connected with the sliding block, and the other end extends into the oil hydraulic cylinder; the spring is sleeved on the piston rod; the piston is fixed on the piston rod and divides the oil hydraulic cylinder into a rod cavity and a rodless cavity, and the rodless cavity is communicated with a medium-pressure cavity of the compressor; the sliding block can slide in the sliding groove in the moving direction of the piston rod. The electromagnetic valve controls oil pressure of a rod cavity of the oil hydraulic cylinder, and then the piston is driven to move in the oil hydraulic cylinder, so that loading or unloading of the compressor is achieved. By means of the structural design, loading and unloading of the compressor can be achieved, the pressure of the oil hydraulic cylinder is balanced through communication of the rodless cavity and the medium-pressure cavity, and piston movement is more stable.

Description

Technical Field

[0001] This utility model relates to the field of refrigerant compressors, and in particular to a compressor capacity adjustment structure. Background Technology

[0002] Screw compressors are widely used in refrigeration, air conditioning, and chemical industries due to their simple structure, high reliability, and large discharge capacity. To adapt to different operating conditions, screw compressors typically require a capacity regulating mechanism to adjust the compressor's discharge capacity, improve its operating efficiency, and reduce energy consumption.

[0003] The traditional methods for adjusting the capacity of screw compressors mainly include the following:

[0004] Slide valve adjustment: This method adjusts the intake volume by changing the opening area of ​​the intake port, thereby achieving capacity regulation. While simple in structure, this method has a limited adjustment range and is prone to generating airflow noise.

[0005] Variable frequency drive (VFD): This method adjusts the compressor's discharge volume by changing the motor speed. It offers high precision and efficiency, but is more expensive and requires high-quality power grid.

[0006] Unloading adjustment: When the system load decreases, the compressor stops compressing and enters an unloading state to reduce the discharge volume. This method is simple in structure and low in cost, but the adjustment accuracy is low, and frequent start-stop cycles can cause some stress on the compressor.

[0007] In single-unit two-stage screw compressors, to achieve finer capacity control, it is typically necessary to adjust the capacity on both the high-pressure and low-pressure sides separately. Currently, high-pressure side capacity adjustment mainly employs the following two methods:

[0008] Automatic differential pressure control: This method uses the pressure difference between the high and low pressure sides to drive the slider to move, thereby automatically adjusting the capacity on the high-pressure side. While simple in structure and low in cost, this method has limited adjustment accuracy, slow response speed, and cannot meet the requirements for light-load start-up.

[0009] Hydraulic or pneumatic control: This method utilizes an external hydraulic or pneumatic system to control the movement of the slider, thereby achieving high-pressure side capacity regulation. While this method offers high regulation accuracy and fast response, it is structurally complex, costly, and requires an additional hydraulic or pneumatic system, increasing system complexity and maintenance costs.

[0010] However, the aforementioned prior art has the following technical problems:

[0011] Difficulty in starting under light load: Traditional differential pressure automatic control methods cannot drive the slider to move under low differential pressure conditions, making it difficult for the compressor to start under light load conditions, requiring a larger starting current, which impacts the power grid.

[0012] Low operating efficiency: Most existing high-pressure side capacity adjustment methods can only achieve simple loading or unloading, and cannot make fine adjustments according to the actual load, resulting in low operating efficiency of the compressor under partial load conditions and energy waste.

[0013] Complex structure and high cost: Some high-pressure side capacity regulation methods require additional hydraulic or pneumatic systems, which increases the complexity and cost of the system.

[0014] Therefore, it is necessary to develop a compressor capacity adjustment structure that is simple in structure, low in cost, capable of light-load start-up, and capable of fine adjustment according to actual load, in order to solve the above-mentioned technical problems. Utility Model Content

[0015] This utility model provides a compressor capacity adjustment structure, which aims to solve the technical problems existing in the prior art, such as difficulty in starting under light load, low operating efficiency, and complex structure.

[0016] The technical solution of this utility model is as follows:

[0017] A compressor capacity adjustment structure includes: a housing; a solenoid valve mounted on the housing; a bearing housing mounted on the housing, with a hydraulic cylinder formed inside the bearing housing; a slider located in a sliding groove within the housing; a piston rod, one end connected to the slider and the other end extending into the hydraulic cylinder; a spring sleeved on the piston rod; and a piston fixed to the piston rod, dividing the hydraulic cylinder into a rod chamber and a rodless chamber, the rodless chamber communicating with the intermediate pressure chamber of the compressor; the slider can slide within the sliding groove along the direction of piston rod movement; wherein, the solenoid valve controls the oil pressure in the rod chamber of the hydraulic cylinder, thereby driving the piston to move within the hydraulic cylinder to achieve compressor loading or unloading. This structural design enables compressor loading and unloading, and the communication between the rodless chamber and the intermediate pressure chamber balances the hydraulic cylinder pressure, resulting in smoother piston movement. Furthermore, the structure is simple and easy to implement.

[0018] Preferably, the slider contacts the lower side wall of the groove. This design clarifies the contact method between the slider and the groove, limits the slider's movement trajectory, and enables it to slide stably within the groove, avoiding tilting or jamming.

[0019] Preferably, the piston rod is connected to the portion of the slider near the lower sidewall. Connecting the piston rod near the lower sidewall reduces the bending moment it bears, increases its bending strength, and further ensures the stability of the slider's movement.

[0020] Preferably, the upper sidewall is closer to the outer side of the housing, and the piston rod is located on the axis of the hydraulic cylinder. Designing the upper sidewall closer to the outer side of the housing provides more space for the hydraulic cylinder, facilitating installation and maintenance. Simultaneously, the piston rod's location on the cylinder's axis ensures linear movement of the piston within the cylinder, improving transmission efficiency and reducing wear.

[0021] In summary, this invention achieves precise control over the loading and unloading of the compressor by connecting the rodless chamber of the hydraulic cylinder to the intermediate pressure chamber of the compressor and using a solenoid valve to control the oil pressure in the rod chamber of the hydraulic cylinder, while ensuring the smoothness of piston movement. Especially during light-load starts, even with a small pressure difference, the solenoid valve can control the oil pressure to drive the piston movement, thus overcoming the problem of difficult light-load starts in existing technologies. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the compressor capacity adjustment structure according to an embodiment of the present invention. Detailed Implementation

[0023] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0024] Figure 1 This is a schematic diagram of the compressor capacity adjustment structure according to an embodiment of the present invention, as shown below. Figure 1 As shown, this utility model provides a compressor capacity adjustment structure, mainly applied to the high-pressure side capacity adjustment of a single-unit two-stage screw compressor. The structure includes: a housing 1, a solenoid valve 2, a bearing seat 3, a slider 4, a piston rod 5, a spring 6, a piston 7, a slide groove 8, and a lower side wall 12.

[0025] The housing 1 is part of the compressor and serves to support and protect other components. The solenoid valve 2 is mounted on the housing 1 and controls the oil pressure in the rod chamber A of the hydraulic cylinder, thereby controlling the loading or unloading of the compressor. The bearing housing 3 is mounted on the housing 1 and forms the hydraulic cylinder inside, within which the piston 7 and piston rod 5 reciprocate.

[0026] The slider 4 is located within the slide groove 8 inside the housing 1. The slide groove 8 is provided on the housing 1 to guide the movement trajectory of the slider 4 and to bear the compressor working pressure transmitted by the slider 4. The slider 4 is connected to the piston rod 5 and can slide within the slide groove 8 along the movement direction of the piston rod 5.

[0027] One end of the piston rod 5 is connected to the slider 4, and the other end extends into the hydraulic cylinder and is fixedly connected to the piston 7. The spring 6 is sleeved on the piston rod 5, located between the slider 4 and the hydraulic cylinder end cover, and is used to provide a restoring force so that the slider 4 can automatically return to the initial position when the solenoid valve 2 is de-energized.

[0028] Piston 7 is fixed to piston rod 5, dividing the hydraulic cylinder into rod chamber A and rodless chamber B. Rod chamber A is connected to solenoid valve 2 via an oil passage, while rodless chamber B is connected to the intermediate pressure chamber of the compressor via an oil passage.

[0029] The working principle of this utility model is as follows:

[0030] When the compressor needs to be loaded, solenoid valve 2 is de-energized, and oil in the rod chamber A of the hydraulic cylinder flows to the low-pressure side, pushing piston 7 to move to the left. The movement of piston 7 causes piston rod 5 to move to the right, which in turn causes slider 4 to slide to the left in the slide groove 8, thereby changing the compression ratio on the high-pressure side of the compressor and loading the compressor.

[0031] When the compressor needs to be unloaded, solenoid valve 2 is energized, connecting the pressure in control chamber A with the high-pressure oil pressure, allowing oil to flow into the rod chamber A of the hydraulic cylinder. At this time, combined with the action of spring 6, piston 7, piston rod 5, and slider 4 move to the right until they return to their initial positions, thereby changing the compression ratio on the high-pressure side of the compressor and achieving compressor unloading.

[0032] To ensure that the slider 4 slides stably within the groove 8, the present invention incorporates the following features:

[0033] The slider 4 contacts the groove 8 and the lower side wall 12. This design clarifies the contact method between the slider 4 and the groove 8, limits the movement trajectory of the slider 4, avoids tilting or jamming of the slider 4 during movement, and ensures the smooth movement of the slider 4.

[0034] The piston rod 5 is connected to the portion of the slider 4 near the lower side wall 12. To further improve the stability of the slider 4's movement, this invention connects the piston rod 5 to the position of the slider 4 near the lower side wall 12. This design reduces the bending moment borne by the piston rod 5, improves the bending strength of the piston rod 5, and thus ensures the stability of the slider 4's movement.

[0035] The piston rod 5 is located on the axis of the hydraulic cylinder. This provides more space for the hydraulic cylinder, facilitating installation and maintenance. Simultaneously, the design of the piston rod 5 being on the axis of the hydraulic cylinder ensures that the piston 7 moves linearly within the cylinder, improving transmission efficiency and reducing wear.

[0036] In summary, the compressor capacity adjustment structure provided by this utility model achieves precise control of compressor loading or unloading by connecting the rodless chamber B of the hydraulic cylinder to the intermediate pressure chamber of the compressor and using the solenoid valve 2 to control the oil pressure in the rod chamber A of the hydraulic cylinder, while ensuring the smoothness of piston movement. Especially during light-load startup, even with a small high-low pressure difference, the solenoid valve 2 can control the oil pressure to drive the piston 7 to move, thus overcoming the problem of difficult light-load startup in existing technologies.

[0037] The above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A compressor capacity adjustment structure, characterized in that, include: Casing (1); Solenoid valve (2) is installed on the housing (1); A bearing housing (3) is installed on the housing (1), and a hydraulic cylinder is formed inside the bearing housing (3); The slider (4) is located in the groove (8) within the inner travel of the housing (1); The piston rod (5) is connected at one end to the slider (4) and at the other end extends into the hydraulic cylinder; A spring (6) is fitted onto the piston rod (5); The piston (7) is fixed on the piston rod (5) and divides the hydraulic cylinder into a rod chamber (A) and a rodless chamber (B), wherein the rodless chamber (B) is connected to the intermediate pressure chamber of the compressor; The slider (4) can slide within the groove (8) along the direction of movement of the piston rod (5); The solenoid valve (2) controls the oil pressure in the rod chamber (A) of the hydraulic cylinder, thereby driving the piston (7) to move within the hydraulic cylinder to load or unload the compressor.

2. The compressor capacity adjustment structure according to claim 1, characterized in that, The slider (4) contacts the lower sidewall (12) of the groove (8).

3. The compressor capacity adjustment structure according to claim 2, characterized in that, The piston rod (5) is connected to the portion of the slider (4) near the lower sidewall (12).

4. The compressor capacity adjustment structure according to claim 3, characterized in that, The piston rod (5) is located on the axis of the hydraulic cylinder.

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