Scroll compressor and bypass valve assembly

Abstract

The application provides a scroll compressor and bypass valve assembly, and relates to the technical field of scroll compressors.The bypass valve assembly based on the scroll compressor comprises a static scroll disc, a tapered hole with a top wide and a bottom narrow is formed in the top of the static scroll disc at a compression cavity position, a valve body is arranged in the tapered hole, the middle part of the valve body is hollow, the upper part of the valve body is in a cylindrical shape, the lower part of the valve body is provided with a tapered surface with a taper corresponding to the tapered hole, and at least three groups of through holes are formed in the tapered surface.The valve body of the application is made of a polymer material, instead of a steel valve body used in a conventional scroll compressor bypass valve, the impact noise generated by the polymer valve body and a steel valve seat during the opening and closing process of the valve body is smaller than the noise generated by the steel valve body and the steel valve seat, so that the purpose of reducing noise is achieved, and when hard particle foreign matters enter the refrigeration system and pass through the bypass valve assembly in the embodiment, the hard particles can be embedded in the valve body because the valve body is made of a plastic material, and the work of the scroll compressor is not affected.

Description

Technical Field

[0001] This invention relates to the field of scroll compressor technology, specifically to a scroll compressor and a bypass valve assembly. Background Technology

[0002] A scroll compressor is a highly efficient and energy-saving positive displacement fluid machine. Its core consists of a pair of stationary and moving scrolls with an involute structure, which mesh in a staggered manner to form multiple sets of crescent-shaped closed compression chambers. During operation, the moving scroll, driven by a drive mechanism, performs a non-rotating revolution, causing the compression chambers to continuously contract towards the center, achieving continuous gas intake, compression, and discharge. Its compression process is smooth, with minimal airflow pulsation, and it boasts significant advantages such as high volumetric efficiency, low vibration and noise, compact structure, fewer parts, and reliable operation. Its overall performance surpasses that of traditional reciprocating compressors. Currently, it is widely used in household and commercial air conditioning, refrigeration units, automotive air conditioning, air compression and vacuum pumps, and is a mainstream core power component in small and medium-sized refrigeration and compression equipment.

[0003] Under a wide range of operating conditions, scroll compressors often have one or more pairs of intermediate pressure bypass valve assemblies. The function of these intermediate pressure bypass valve assemblies is to, when the compressor is operating at a low pressure ratio, accumulate the exhaust gas through the intermediate pressure bypass valve assembly to perform the exhaust process together. The conventional bypass valve assembly for the intermediate pressure chamber typically employs... Figure 7 The steel reed valve shown forms a clearance volume in the airflow passage between the valve and the compression chamber of the scroll assembly. After exhaust, the high-pressure gas remaining in the clearance volume will backflow into the next compression chamber and expand rapidly. Recompressing this gas consumes additional compressor power, leading to a decrease in compressor efficiency. Simultaneously, the opening and closing process of the steel reed valve generates impact noise on the valve seat machined on the surface of the stationary scroll. Figure 10 and 11 As shown, when hard foreign objects enter the conventional bypass valve assembly, because the valve plate is made of steel, the hard particles will get stuck between the valve plate and the upper surface of the stationary scroll plate. The valve plate and the upper surface of the stationary scroll plate cannot keep in contact, and the compressor cannot work normally. Furthermore, as the compressor crankshaft rotates continuously, the valve plate will continuously collide with the hard particles. There is a risk of breakage at the point of impact with the particles, indicating room for further improvement. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a scroll compressor and a bypass valve assembly, which reduces the clearance volume generated after the fluid discharge process in the compression chamber of the scroll compressor is completed, thereby reducing the compressor's power consumption. This solves the problem of clearance volume and impact noise generated by using steel reed valve plates in existing conventional bypass valve assemblies.

[0005] (II) Technical Solution To achieve the above objectives, the present invention is implemented through the following technical solution: a scroll compressor and bypass valve assembly, including a valve body, the valve body having a hollow center, a tapered side surface with at least 3 sets of through holes on the tapered surface, and a cylindrical side surface.

[0006] The preload spring is a cylindrical steel wire spring or a conical spring. One end of the spring or the small end face of the conical spring is in contact with the valve body, and the other end or the large end face of the conical spring is in contact with the inner top surface of the pressure valve cover.

[0007] The top of the pressure valve cover has a through hole and a boss with a positioning preload spring inside. The middle part has a large inner hole that fits with the cylindrical surface of the valve body. The bottom conical surface has at least three sets of vent holes. The pressure valve cover is connected to the stationary vortex disk by bolts and fixed to the top surface of the stationary vortex disk.

[0008] A tapered hole is opened on the top surface of the stationary vortex disk at a suitable position corresponding to the compression chamber.

[0009] Preferably, the valve body is made of high-strength, high-temperature resistant, and wear-resistant polymer material, such as polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK), but not limited to PTFE and PEEK; the hollowed-out part in the middle of the valve body contains the preload spring, and the inner diameter of the hollowed-out part is designed to have a gap of 0.2~0.5 mm between the maximum outer diameter of the preload spring and the inner diameter of the hollowed-out part; the small end face of the valve body maintains a certain height difference with the bottom surface of the turbine blade of the stationary vortex disk, and the height difference is designed to be 0.4~0.6 mm for PTFE material and 0.2~0.4 mm for PEEK material.

[0010] Preferably, the pressure valve cover encloses the valve body, and the inner hole in the middle of the pressure valve cover is clearance-fitted with the cylindrical outer diameter of the valve body, with a clearance value designed to be 0.02~0.1; the recessed part at the top of the pressure valve cover encloses one end of the cylindrical spring or the large end of the conical spring, and its recessed depth is 1.0~1.5 greater than the compression length of the spring; the outer diameter of the protruding part at the top of the pressure valve cover is clearance-fitted with the inner diameter of the preload spring, with a clearance value designed to be 0.15~0.3.

[0011] Preferably, a through hole is opened at the center of the top of the pressure valve cover as one of the channels for fluid discharge, and the single-sided wall thickness formed by the inner diameter of the through hole and the outer diameter of the boss is designed to be 0.6~1.0.

[0012] Preferably, the lower conical section on the side of the valve body has a taper of 5° to 15°. The through hole on the conical section serves as one of the fluid discharge channels. The high-pressure refrigerant fluid generated by the movement of the scroll assembly is discharged from the compression chamber through the through hole on the conical surface.

[0013] Preferably, a tapered hole is provided at the top of the stationary vortex disk, and its taper is consistent with the taper designed for the lower part of the valve body side. The outer surface of the lower cone of the valve body and the inner surface of the cone of the stationary vortex disk have the same taper and are concentric. When the pressure in the compression chamber does not reach the pressure outside the chamber and the valve body is in the closed state, a sealing surface is formed to prevent fluid from escaping from the compression chamber. At the same time, the small end face of the valve body is recessed into the inner cone surface of the stationary vortex and maintains a certain depth to compensate for the wear and sinking of the valve body cone surface. The recessed depth is based on the fact that the small end face of the valve body is flush with the bottom surface of the vortex of the stationary vortex disk after 10,000 hours of use.

[0014] Preferably, the fitting characteristics of the valve cover and the large end diameter of the conical hole of the stationary vortex are as follows: the center of the valve cover and the center of the conical hole of the stationary vortex are concentric, the bottom surface of the valve cover is in contact with the top surface of the stationary vortex, and they are fixed with fastening bolts.

[0015] Preferably, the fitting characteristics between the pressure valve cover and the outer diameter of the valve body cylinder are as follows: the center inner surface of the pressure valve cover is concentric with the center of the outer surface of the valve body cylinder, and the valve body can move freely up and down on the center inner surface of the pressure valve cover. When the fluid pressure in the compression chamber is greater than the pressure outside the chamber, the existence of the pressure difference between the inside and outside fluids pushes the valve body open, and the pre-compression spring is compressed and deepened. When the upper end face of the valve body is flush with and fits the concave end face, the spring pressure reaches the limit value, and the fluid discharge flow area reaches the maximum value.

[0016] A scroll compressor includes a scroll compressor body and a motor. The motor is installed inside the scroll compressor body. An eccentric shaft is driven to the rotor shaft of the motor. A moving scroll is driven to the end of the eccentric shaft away from the motor. A stationary scroll is installed at the end of the scroll compressor body. The feature is that the top surface of the stationary scroll is equipped with one or more pairs of bypass valve assemblies as described in any one of claims 1-7.

[0017] (III) Beneficial Effects This invention provides a scroll compressor and a bypass valve assembly. It offers the following advantages: 1. The valve body of the present invention is made of polymer material, replacing the steel valve body used in the bypass valve of the traditional scroll compressor. During the opening and closing of the valve body, the impact noise generated by the polymer valve body and the steel valve seat is less than the noise generated by the steel valve body and the steel valve seat, thereby achieving the purpose of noise reduction. Moreover, when hard particulate foreign substances enter the refrigeration system and pass through the bypass valve group in this embodiment, because the valve body is made of plastic material, the hard particles can be embedded in the valve body and will not affect the operation of the scroll compressor. The operational reliability is higher than that of conventional bypass valves.

[0018] 2. The compressor of the present invention operates under high pressure ratio conditions. The fluid pressure outside the compression chamber is always greater than the fluid pressure inside the compression chamber. The valve body remains stationary and almost completely fills the conical through hole of the stationary scroll plate. During the operation of the scroll compressor, the compression chamber passes through the conical hole of the stationary scroll plate and hardly forms any clearance volume. Attached Figure Description

[0019] Figure 1 This is a longitudinal sectional view of a scroll compressor according to the present invention; Figure 2 This is a schematic diagram of the structure of a bypass valve assembly according to the present invention; Figure 3 This is an exploded view of the components of a bypass valve assembly according to the present invention; Figure 4 This is a schematic diagram of a bypass valve assembly in the closed state according to the present invention; Figure 5 This is a schematic diagram of the valve body of a bypass valve assembly of the present invention in the open state; Figure 6 This is a schematic diagram of the clearance volume of the bypass valve of the present invention; Figure 7 This is a schematic diagram of the clearance volume of a conventional bypass valve for a scroll compressor. Figure 8 This is a schematic diagram showing the changes in the valve body when the bypass valve of the present invention encounters hard particulate foreign matter. Figure 9 for Figure 8 A magnified view of a portion of the image; Figure 10 This is a schematic diagram showing the changes that occur in the valve body of a conventional bypass valve of a scroll compressor when it encounters hard particulate foreign matter. Figure 11 for Figure 10 A magnified view of a portion of the image.

[0020] The components include: 1. main body of scroll compressor; 2. motor; 3. eccentric shaft; 4. moving scroll; 5. stationary scroll; 6. valve body; 7. preload spring; and 8. pressure valve cover.

[0021] at the same time, Figure 4 The gas force inside the compression chamber is less than the sum of the gas force outside the chamber and the spring force; Figure 5 The gas force inside the compression chamber is greater than the sum of the gas force outside the chamber and the spring force. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: like Figure 1 As shown, the main body 1 of the scroll compressor is powered on by the motor 2, causing the rotor to rotate and drive the eccentric shaft 3 to rotate. The centrifugal force of the eccentric crank of the eccentric shaft 3 drives the moving scroll 4 to perform a revolution-translational motion, forming several compression chambers. When the fluid pressure inside the compression chamber where the bypass valve group is located is greater than the external pressure, the bypass valve is pushed open to allow bypass exhaust. When the fluid pressure inside the compression chamber where the bypass valve group is located is less than the external pressure, bypass exhaust does not activate. The prerequisite for the bypass valve group valve body 6 to activate is that the fluid pressure inside the compression chamber is greater than the external pressure.

[0024] like Figure 2 As shown, the bypass port of the stationary scroll 5 is a conical opening, wider at the top and narrower at the bottom, with a taper of 5°~15°. Correspondingly, the lower outer periphery of the valve body 6 has a conical plug, also wider at the top and narrower at the bottom. The stationary scroll 5 and the moving scroll 4 form a compression chamber at the bypass port, containing the compressed fluid, which, for a refrigeration compressor, is compressed refrigerant gas. The preload spring 7 provides a clamping force to the valve body 6, pressing it down so that the conical surface of the valve body 6 fits against the conical surface of the bypass port of the stationary scroll 5. This fit of the two conical surfaces forms a closed container within the compression chamber. The pressure valve cover 8 is fixed to the upper surface of the stationary scroll 5 by fixing bolts. The pressure valve cover 8 restricts the vertical movement range of the preload spring 7 and guides the vertical movement of the valve body 6.

[0025] Figure 3 This is a detailed exploded view of the components of the bypass valve assembly in this embodiment. Figure 3 Multiple vent holes are provided around the conical surface of the valve body 6. Multiple vent holes are provided around the cylindrical surface of the pressure valve cover 8. Multiple vent holes are provided on the top of the pressure valve cover 8. All holes provide a flow path for the fluid.

[0026] like Figure 4 As shown, the fluid pressure inside the compression chamber applies a gas force Fgas to the valve body 6, in the upward direction; the preload spring 7 applies a spring force FS to the valve body 6, in the downward direction; and the exhaust pressure outside the compression chamber applies a gas force Fdis to the valve body 6, in the downward direction.

[0027] like Figure 4As shown, under high pressure ratio conditions, the force Fgas exerted by the gas in the compression chamber on the valve body 6 is not greater than the sum of the spring force FS exerted by the preload spring 7 on the valve body 6 and the gas force Fdis exerted by the exhaust pressure outside the compression chamber on the valve body 6, that is, Fgas≤Fs+Fdis, and the valve body 6 will not move.

[0028] like Figure 5 As shown, under low pressure ratio conditions, the force Fgas exerted by the gas in the compression chamber on the valve body 6 is greater than the sum of the spring force FS exerted by the preload spring 7 on the valve body 6 and the gas force Fdis exerted by the exhaust pressure outside the compression chamber on the valve body 6, that is, Fgas>Fs+Fdis, and the valve body 6 will slide upward along the inner wall of the pressure valve cover 8.

[0029] Figure 5 The outer conical surface of the valve body 6 disengages from the inner conical surface of the stationary vortex disk 5, creating a gap between them. Gas in the compression chamber leaks out through this gap, and the bypass valve assembly is in the exhaust process. As the eccentric shaft 3 continues to rotate, the volume of the compression chamber continuously decreases, and the force Fgas exerted by the gas in the chamber on the valve body 6 continuously increases. The valve body 6 continues to slide upwards along the inner wall of the pressure valve cover 8 until the upper end face of the valve body 6 contacts the inner end face of the top of the pressure valve cover 8. At this point, the gap reaches its maximum value, max. The gas discharge path in the compression chamber is as follows... Figure 5 The direction of airflow.

[0030] Figure 6 The bolded portion represents the clearance volume between the lower end face of the valve body 6 and the lower end face of the stationary scroll plate 5 under high pressure ratio conditions (Fgas > Fs + Fdis) in this embodiment. To prevent the valve body 6 from wearing down and colliding with the moving scroll plate 4, a height difference ΔH is reserved, designed to be approximately 0.15H, where H is the thickness between the upper and lower end faces of the stationary scroll plate 5. The clearance volume V1 is approximately considered to be generated by the area of ​​the lower conical opening of the stationary scroll plate 5 and the height difference ΔH. Therefore, the clearance volume V1 generated by the bypass valve assembly in this embodiment can be calculated to be approximately 0.15πD²H / 4.

[0031] Figure 7 The bypass valve structure commonly used in the main body 1 of the scroll compressor is used as a comparison of the bypass valve assembly of this invention. This structure consists of a steel valve plate, a valve plate lift limiter, and bolts fixing one end of the valve plate, i.e., the valve plate lift limiter. Figure 7 It can be seen that the clearance volume V2 generated by the traditional bypass valve assembly is produced by the flow port area and height H of the stationary vortex disk 5. Therefore, the clearance volume V2 generated by the traditional bypass valve assembly can be calculated to be approximately πD²H / 4.

[0032] Therefore, it can be concluded that the clearance volume V1 generated by the bypass valve group of the scroll compressor body 1 implemented by this invention is about 15% of the clearance volume V2 of the conventional bypass valve group, that is, V1≈0.15V2.

[0033] Figure 8 The diagram shown illustrates the bypass valve of this embodiment encountering hard, particulate foreign matter. Figure 9 for Figure 8 Enlarged view. When a hard foreign object enters the bypass valve assembly of the present invention, since the valve body 6 is made of plastic material, the hard particle can be embedded in the valve body 6. After embedding, the high-temperature resistant and high-strength plastic valve body 6 can still maintain contact with the inner conical surface of the stationary scroll plate 5, and the compressor can still work normally.

[0034] Figure 11 The diagram shows a conventional bypass valve of the scroll compressor body 1 encountering hard particulate foreign matter. Figure 11 for Figure 10 Enlarged view. When hard foreign objects enter the conventional bypass valve assembly, because the valve plate is made of steel, the hard particles will get stuck between the valve plate and the upper surface of the stationary scroll plate 5. The valve plate and the upper surface of the stationary scroll plate 5 cannot keep in contact, the compressor cannot work normally, and as the compressor eccentric shaft 3 continues to rotate, the valve plate will continuously collide with the hard particles, and there is a risk of breakage at the point of impact with the particles.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bypass valve assembly, comprising a stationary scroll plate (5), characterized in that: The top of the static vortex disk (5) has a tapered hole that is wider at the top and narrower at the bottom at the compression chamber position, and a valve body (6) is provided in the tapered hole. The valve body (6) has a hollow center, and the upper part of the valve body (6) is cylindrical while the lower part has a tapered surface with a taper corresponding to the tapered hole. At least three sets of through holes are opened on the tapered surface. The static vortex disk (5) is fixedly connected to a pressure valve cover (8) on the outside of the valve body (6). A pre-compression spring (7) is provided inside the pressure valve cover (8) above the valve body (6). The pressure valve cover (8) has a through hole at the top, a large inner hole in the middle that is in clearance fit with the upper cylindrical surface of the valve body (6), and a vent hole at the bottom corresponding to the position of the lower conical surface of the valve body (6) corresponding to the through hole.

2. A bypass valve assembly according to claim 1, characterized in that: The preload spring (7) can be a cylindrical wire spring or a conical spring. One end of the spring or the small end face of the conical spring is in contact with the valve body (6), and the other end or the large end face of the conical spring is in contact with the inner top surface of the pressure valve cover (8). The pressure valve cover (8) has a boss inside for positioning the preload spring (7).

3. A bypass valve assembly according to claim 1, characterized in that: The valve body (6) is made of high-strength, high-temperature resistant, and wear-resistant polymer materials, including but not limited to polytetrafluoroethylene or polyetheretherketone. The hollow part in the middle of the valve body (6) encloses the preload spring (7). The inner diameter of the hollow part and the maximum outer diameter of the preload spring (7) are designed to have a gap of 0.2~0.

5. The small end face of the valve body (6) and the bottom surface of the turbine blade of the stationary vortex disk (5) maintain a certain height difference. The height difference is designed to be 0.4~0.6 for polytetrafluoroethylene material and 0.2~0.4 for polyetheretherketone material.

4. A bypass valve assembly according to claim 1, characterized in that: The inner hole in the middle of the pressure valve cover (8) is clearance-fitted with the outer diameter of the cylinder of the valve body (6), with a clearance value designed to be 0.02~0.1; the outer diameter of the protruding part at the top of the pressure valve cover (8) is clearance-fitted with the inner diameter of the preload spring (7), with a clearance value designed to be 0.15~0.3; a through hole is opened at the center of the top of the pressure valve cover (8) as one of the channels for fluid discharge, and the single-sided wall thickness formed by the inner diameter of the through hole and the outer diameter of the boss is designed to be 0.6~1.

0.

5. A bypass valve assembly according to claim 1, characterized in that: The lower conical part of the valve body (6) is designed with a taper of 5°~15°. The through hole opened on the conical part serves as one of the fluid discharge channels. The high-pressure refrigerant fluid generated by the movement of the vortex assembly is discharged from the compression chamber through the through hole opened on the conical surface.

6. A bypass valve assembly according to claim 1, characterized in that: The center of the pressure valve cover (8) is concentric with the center of the conical hole of the static vortex disk (5), and the bottom surface of the pressure valve cover (8) and the top surface of the static vortex disk (5) are fixedly connected by fastening bolts.

7. A bypass valve assembly according to claim 1, characterized in that: The inner center of the pressure valve cover (8) is concentric with the outer center of the cylindrical surface of the valve body (6).

8. A scroll compressor, comprising a scroll compressor body (1) and a motor (2), wherein the motor (2) is disposed inside the scroll compressor body (1), the rotor shaft of the motor (2) is drivenly connected to an eccentric shaft (3), a moving scroll (4) is drivenly connected to the end of the eccentric shaft (3) away from the motor (2), and a stationary scroll (5) is disposed at the end of the scroll compressor body (1), characterized in that: The top surface of the static vortex disk (5) is equipped with one or more pairs of bypass valve assemblies as described in any one of claims 1-7.

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