Upper bearing assembly and compressor

Abstract

The invention discloses an upper bearing assembly and a compressor, and relates to the technical field of compressors, the upper bearing assembly is applied to the compressor, the upper bearing assembly comprises a valve seat, a limiter and an exhaust valve plate, the valve seat is provided with a mounting groove, and the groove bottom of the mounting groove is provided with an exhaust port; the exhaust valve plate and the limiter are arranged in the mounting groove, and a free end cover of the exhaust valve plate covers the exhaust port and can move between the limiter and the exhaust port so as to open and close the exhaust port; the side, facing the exhaust valve plate, of the valve seat is provided with a groove, and the groove is formed in the periphery of the exhaust port. According to the technical scheme, the groove is formed in the side, facing the exhaust valve plate, of the valve seat, the groove is formed in the periphery of the exhaust port, the local rigidity of the valve seat is reduced, and therefore the impact load generated when the valve seat is impacted by the exhaust valve plate is effectively reduced, and the anti-fatigue performance of the exhaust valve plate is improved.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to an upper bearing assembly and a compressor. Background Technology

[0002] The upper bearing assembly of a compressor typically uses a reed-type exhaust valve. This type of upper bearing assembly usually includes an exhaust valve, a valve seat, and a limit switch. During compressor operation, the exhaust valve periodically opens and closes the exhaust port on the valve seat under the influence of pressure differential to control gas compression and discharge. However, during the exhaust valve's rebound closure, the high-speed impact of the exhaust valve against the valve seat generates significant impact stress in a localized area. This repeated impact load can easily lead to exhaust valve fatigue failure, thus affecting the compressor's reliability and service life. Summary of the Invention

[0003] The main objective of this invention is to provide an upper bearing assembly and a compressor, which aims to effectively reduce the impact load when the exhaust valve plate impacts the valve seat, thereby improving the fatigue resistance of the exhaust valve plate.

[0004] To achieve the above objectives, the present invention provides an upper bearing assembly applied to a compressor, the upper bearing assembly comprising:

[0005] The valve seat is provided with a mounting groove, and the bottom of the mounting groove is provided with an exhaust port; A limiter is installed in the mounting slot; An exhaust valve plate is disposed in the mounting groove and located below the limiter. The free end of the exhaust valve plate covers the exhaust port and can move between the limiter and the exhaust port to open and close the exhaust port. The valve seat has a groove on the side facing the exhaust valve plate, and the groove is located on the outer periphery of the exhaust port.

[0006] In one embodiment, the groove is circumferentially disposed around the outer periphery of the exhaust port.

[0007] In one embodiment, the grooves are provided in multiple ways, and the multiple grooves are distributed at intervals along the circumference of the exhaust port. Each groove is arc-shaped and extends along the circumference of the exhaust port.

[0008] In one embodiment, the distance from the side edge of the groove away from the central axis of the exhaust port to the central axis of the exhaust port is D, and the minimum distance from the bottom of the groove to the side of the valve seat away from the exhaust valve plate is h, where h and D satisfy... ;in, This is the maximum difference between the discharge pressure and the suction pressure of the compressor. The yield stress of the valve seat material is given.

[0009] In one embodiment, a transition section is formed between the inner edge of the groove and the edge of the exhaust port. The surface of the transition section, when cut by a plane extending axially along the exhaust port, includes a first arc segment protruding toward the exhaust valve plate. The inner wall of the groove, when cut by a plane extending axially along the exhaust port, includes a straight segment and a second arc segment. The straight segment is located between the first arc segment and the second arc segment and is smoothly connected to the first arc segment and the second arc segment.

[0010] In one embodiment, the length of the straight segment is t, and the minimum distance from the bottom of the groove to the side of the valve seat away from the exhaust valve plate is h, where t and h satisfy: 0.2h≤t≤0.4h.

[0011] In one embodiment, the distance from the side edge of the groove away from the central axis of the exhaust port to the central axis of the exhaust port is D, and the radius of the exhaust port is d, where D and d satisfy: 1.75d≤D≤2.8d.

[0012] In one embodiment, the distance between the two opposite sides of the valve seat in the axial direction of the exhaust port is H, the minimum distance from the bottom of the groove to the side of the valve seat away from the exhaust valve plate is h, and the radius of the second arc segment is r. H, h and r satisfy: r≥2(Hh).

[0013] In one embodiment, the limiter includes a fixed section and a limiting section distributed along its length direction. The fixed section is mounted on the valve seat, and the limiting section is disposed at a distance from the exhaust valve plate. The side of the limiting section facing the exhaust valve plate includes a connected arcuate section and a planar section along its length direction, and the arcuate section is closer to the fixed section relative to the planar section.

[0014] In one embodiment, the arc segment and the planar segment are tangent, and the central axis of the exhaust port passes through the point of tangency between the arc segment and the planar segment.

[0015] In one embodiment, in the cross-section of the limiter cut by a reference plane, the intersection point of the extension line of the arc segment and the end face of the limiter segment away from the fixed segment is denoted as m; the intersection point of the planar segment and the end face of the limiter segment away from the fixed segment is denoted as n; the distance from intersection point m to intersection point n is a; and the maximum lift height of the exhaust valve plate is R. H a and R H Satisfy: a / R H <6%; wherein, the reference surface is a plane that includes the centerline of the limiter in its length direction and is parallel to the central axis of the exhaust port.

[0016] In one embodiment, the sum of the length of the planar segment and the arc length of the arc segment is L. x The exhaust valve plate includes a mounting section and a working section distributed along its length. The mounting section is mounted on the valve seat, and the working section is movable relative to the valve seat. The length of the working section is L. f L f With L x Satisfy: 0≤L f -L x <0.023L f ; The limiter is formed by a cross-section containing the centerline of the limiter in its length direction and parallel to the central axis of the exhaust port. A reference line extends axially along the exhaust port and passes through the center of the arc segment. The fixing segment and the mounting segment are located on the same side of the reference line, and the limiting segment and the working segment are located on the other side of the reference line.

[0017] In one embodiment, the outer contour of the free end of the limiter includes two third arc segments and one fourth arc segment. The two third arc segments are distributed along the width direction of the limiter, and the fourth arc segment is located at one end in the length direction of the limiter, with the two ends of the fourth arc segment respectively connecting to the two third arc segments.

[0018] In one embodiment, the radius of the third arc segment is R1, and the radius of the fourth arc segment is R2, wherein R1 and R2 satisfy: R2 / R1>1.5.

[0019] The present invention also proposes a compressor comprising the aforementioned upper bearing assembly.

[0020] The technical solution of this invention involves providing a groove on the side of the valve seat facing the exhaust valve plate. This groove is located on the outer periphery of the exhaust port. On one hand, it reduces the local stiffness of the valve seat, allowing the valve seat to undergo micro-elastic deformation during the closing impact of the exhaust valve plate, prolonging the impact time and effectively absorbing some of the impact energy. On the other hand, the groove forms a dynamic buffer chamber during the opening and closing of the exhaust valve plate. When the exhaust valve plate closes, the gas in the groove is compressed, creating an air cushion effect that reduces the impact on the valve seat. When the exhaust valve plate opens, the gas expansion further suppresses the impact of the exhaust valve plate on the limit switch. Through the synergistic effect of the softened local structure of the valve seat and the air cushion buffer effect formed by the gas in the groove, the impact stress borne by the exhaust valve plate during high-frequency opening and closing is reduced, effectively alleviating high-cycle fatigue damage caused by repeated impacts, improving the fatigue resistance and service life of the exhaust valve plate, and thus enhancing the operational reliability and durability of the upper bearing assembly of the compressor. Furthermore, the upper bearing assembly of this invention requires no additional parts; it can be achieved simply by machining a groove on the valve seat, offering advantages such as simple structure, convenient processing, and low manufacturing cost. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a bearing embodiment provided by the present invention; Figure 2 A schematic diagram of another embodiment of the bearing provided by the present invention; Figure 3 A cross-sectional view of an embodiment of the upper bearing assembly provided by the present invention; Figure 4 A cross-sectional view of an embodiment of the bearing provided by the present invention; Figure 5 for Figure 4 A magnified view of a section at point A in the middle; Figure 6 for Figure 5 A magnified view of a section at point B in the middle; Figure 7 A cross-sectional view of an embodiment of an upper bearing assembly with its exhaust port in a closed state provided by the present invention; Figure 8 This is a cross-sectional view of an embodiment of the limiter provided by the present invention; Figure 9 for Figure 8 A magnified view of a section at point C; Figure 10 A cross-sectional view of an embodiment of an upper bearing assembly with its exhaust port in an open state provided by the present invention; Figure 11 This is a top view of an embodiment of the limiter provided by the present invention; Figure 12 Stress cloud diagrams of existing limiters and the limiters provided by the present invention under impact from exhaust valve plates; Figure 13 This is a comparison chart showing the noise generated when a limit switch of the prior art and the limit switch provided by the present invention are applied to a compressor.

[0023] Explanation of icon numbers: 10. Bearing; 100. Valve seat; 200. Exhaust valve plate; 300. Limiter; 110. Exhaust port; 120. Groove; 121. Straight section; 122. Second arc section; 130. First arc section; 140. Mounting groove; 210. Mounting section; 220. Working section; 310. Fixing section; 320. Limiting section; 321. Arc section; 322. Planar section; 323. Third arc section; 324. Fourth arc section.

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] This invention proposes an upper bearing assembly.

[0029] Please see Figures 1 to 7 In one embodiment of the present invention, the upper bearing assembly is applied to a compressor. The upper bearing assembly includes a valve seat 100, a limiter 300, and an exhaust valve plate 200. The valve seat 100 is provided with a mounting groove 140, and the bottom of the mounting groove 140 is provided with an exhaust port 110. The limiter 300 is installed in the mounting groove 140. The exhaust valve plate 200 is disposed in the mounting groove 140 and located below the limiter 300. The free end cap of the exhaust valve plate 200 is disposed on the exhaust port 110 and can move between the limiter 300 and the exhaust port 110 to open and close the exhaust port 110. The valve seat 100 is provided with a groove 120 on the side facing the exhaust valve plate 200, and the groove 120 is disposed on the outer periphery of the exhaust port 110.

[0030] Specifically, the upper bearing assembly includes a valve seat 100, a limiter 300, and an exhaust valve plate 200. The valve seat 100 is provided with a mounting groove 140, and the bottom of the mounting groove 140 is provided with an exhaust port 110. The limiter 300 and the exhaust valve plate 200 are both installed in the mounting groove 140. The exhaust valve plate 200 is located below the limiter 300, and the fixed end of the limiter 300 and the fixed end of the exhaust valve plate 200 are coaxially fixed. The two can be fixedly connected to the valve seat 100 by fasteners such as rivets and bolts.

[0031] During the initial intake or compression phase of the compressor operation, the gas pressure in the compression chamber is lower than the pressure in the exhaust chamber (or exhaust pipeline). At this time, the exhaust valve plate 200 is pressed tightly against the exhaust port 110 of the valve seat 100 under the action of the higher gas pressure on the exhaust side. The free end is tightly fitted with the valve seat 100, forming an effective seal to prevent high-pressure gas from flowing back from the exhaust chamber to the compression chamber, thereby maintaining the airtightness and efficiency of the compression process. At this time, the exhaust port 110 is in the closed state. As the compression process continues, the gas in the compression chamber is continuously compressed, and the pressure continues to rise. When the pressure in the compression chamber exceeds the sum of the exhaust chamber pressure and the elastic resistance and inertia of the exhaust valve plate 200 itself, the thrust generated by the pressure difference will overcome the elastic restoring force of the exhaust valve plate 200, causing its free end to tilt upward along the axial direction of the exhaust port 110, away from the valve seat 100, thereby opening the exhaust port 110 and allowing the high-pressure gas to be smoothly discharged into the exhaust chamber, completing the exhaust process. The limiter 300 is used to limit the maximum lift height of the exhaust valve plate 200 during the opening process, preventing it from undergoing plastic deformation or fatigue fracture due to over-opening. When the compression stroke ends or the volume of the compression chamber begins to increase, the pressure in the compression chamber drops rapidly and falls below the pressure in the exhaust chamber. At this time, the pressure difference reverses, and together with the elastic restoring force of the exhaust valve plate 200 itself, it drives the exhaust valve plate 200 to quickly rebound downwards, and the free end re-fits the valve seat 100, achieving rapid closure of the exhaust port 110. However, at the moment of closure, the exhaust valve plate 200 impacts the valve seat 100 at a certain speed, generating a significant impact load. This high-frequency, repeated impact can cause fatigue cracks or even fractures in the exhaust valve plate 200, leading to fatigue failure of the exhaust valve plate 200, which in turn affects the reliability and service life of the compressor.

[0032] The upper bearing assembly of this invention reduces the stiffness of the valve seat 100 by providing a groove 120 on the side of the valve seat 100 facing the exhaust valve plate 200, thereby reducing the impact load when the exhaust valve plate 200 impacts the valve seat 100 and improving the fatigue resistance of the exhaust valve plate 200. Understandably, when the exhaust valve plate 200 rebounds at high speed and impacts the valve seat 100 under pressure differential, the conventionally rigid valve seat 100 will experience high-amplitude impact stress. However, this invention weakens the local stiffness of the valve seat 100 through the groove 120, giving the contact area a certain elastic deformation capacity, thereby absorbing some impact energy, prolonging the impact time, and effectively reducing the instantaneous stress peak value borne by the exhaust valve plate 200. The high-cycle fatigue performance of the exhaust valve plate 200 is significantly improved, making it particularly suitable for high-speed rotary or scroll compressors, effectively delaying crack initiation and propagation, and significantly improving service life and operational reliability. Furthermore, the upper bearing assembly of this invention does not require additional parts (such as buffer pads or springs), and can be achieved simply by machining a groove 120 on the valve seat 100. It features a simple structure, strong manufacturing compatibility, and can be integrally formed using conventional processes such as stamping, milling, or die forging, resulting in low processing costs. Simultaneously, the reduction in impact force also reduces mechanical noise and vibration, contributing to improved NVH (noise, vibration, and harshness) performance of the entire compressor.

[0033] From a mechanical perspective, the groove 120 on the surface of the valve seat 100 reduces local stiffness because it removes some material, reduces the effective load-bearing cross-section, and introduces geometric discontinuities, making this area more susceptible to elastic deformation under stress. The reduction in stiffness (k = F / δ) means a larger displacement under the same impact force, or in other words, a longer impact duration (Δt) under the same kinetic energy input. According to the momentum theorem, the peak impact force F... max The load is directly proportional to the impact velocity v and inversely proportional to the action time Δt (F ∝ v / Δt), thus the flexible contact significantly reduces the peak load. Simultaneously, some of the kinetic energy of the exhaust valve plate 200 is converted into elastic strain energy in the groove 120 region of the valve seat 100, rather than being entirely borne by the exhaust valve plate 200 itself, thereby effectively reducing stress concentration inside the exhaust valve plate 200, especially near the fixed end.

[0034] Furthermore, the reduction in impact load directly improves the fatigue resistance of the exhaust valve plate 200. The main failure mode of the exhaust valve plate 200 is high-cycle fatigue fracture, and its life is closely related to the alternating stress amplitude, following the Basquin fatigue equation: the smaller the stress amplitude, the longer the fatigue life. When the peak impact stress decreases, the damage accumulated by the exhaust valve plate 200 in each opening and closing cycle is reduced, micro-slip and dislocation movement are weakened, and crack nucleation becomes more difficult; even if microcracks exist, the lower stress intensity factor range will significantly slow down the crack propagation rate. Therefore, under long-term high-frequency operation conditions, the overall fatigue life of the exhaust valve plate 200 is extended, and the reliability and durability of the compressor are improved accordingly.

[0035] On the other hand, a groove 120 is provided on the side of the valve seat 100 facing the exhaust valve plate 200. The groove 120 not only serves as a structural softening area to reduce local stiffness, but also forms a dynamic buffer chamber. When the exhaust valve plate 200 rapidly approaches the valve seat 100 under the action of pressure difference and closes the exhaust port 110, the gas inside the groove 120 is rapidly compressed, forming a cushion effect with a certain pressure, thereby damping the movement of the exhaust valve plate 200 and effectively reducing the speed and impact force of its impact on the valve seat 100. During the opening process of the exhaust valve plate 200, as the exhaust valve plate 200 moves away from the valve seat 100, the internal volume of the groove 120 increases and the air pressure decreases. The surrounding high-pressure gas flows in or the original compressed gas expands, producing a reverse buffering effect, which helps to suppress the excessive upward movement of the exhaust valve plate 200 and reduce the impact intensity of the exhaust valve plate 200 on the limiter 300 above it. This passive buffering mechanism based on gas compressibility, in synergy with the structural flexibility provided by the groove 120, further optimizes the dynamic response characteristics of the exhaust valve plate 200 throughout the entire opening and closing cycle. It not only reduces mechanical impact stress but also helps to suppress vibration and noise, thereby improving the overall reliability and durability of the upper bearing assembly.

[0036] It is worth mentioning that the upper bearing assembly includes a bearing 10. In one embodiment, at least a portion of the bearing 10 is configured as a valve seat 100. An exhaust port 110 penetrates at least a portion of the bearing 10 in the axial direction. The limiter 300 and the exhaust valve plate 200 are both located inside the bearing 10. Designing a portion of the bearing 10 directly as the valve seat 100 in the upper bearing assembly not only eliminates the need for a separate valve seat 100 part, simplifying the structural layout of the compressor cylinder or crankcase, but also eliminates problems such as coaxiality deviation, poor sealing, or vibration transmission caused by fit clearance or installation errors between the valve seat 100 and the bearing 10. Since the valve seat 100 and the bearing 10 are integrally formed or integrated, their geometric reference height is uniform, ensuring that key features such as the exhaust port 110, groove 120, and limiter 300 are precisely aligned with the rotating shaft system, thereby improving the stability of the exhaust valve plate 200's movement and sealing reliability. Furthermore, the differential pressure load borne by the valve seat 100 can also be partially borne by the high-strength bearing 10, improving the overall structure's load-bearing capacity and fatigue resistance. In embodiments where at least a portion of the bearing 10 forms the valve seat 100, the material yield stress of the bearing 10 is the same as the material yield stress of the valve seat 100.

[0037] In other embodiments, the bearing 10 and the valve seat 100 may also be separate manufactured parts, that is, the valve seat 100 is mounted on the bearing 10 and extends through both axial ends of the bearing 10.

[0038] The technical solution of the present invention provides a groove 120 on the side of the valve seat 100 facing the exhaust valve plate 200. The groove 120 is located on the outer periphery of the exhaust port 110. On the one hand, it reduces the local stiffness of the valve seat 100, allowing the valve seat 100 to undergo micro-elastic deformation during the closing impact of the exhaust valve plate 200, thus prolonging the impact time and effectively absorbing part of the impact energy. On the other hand, the groove 120 forms a dynamic buffer chamber during the opening and closing of the exhaust valve plate 200. When the exhaust valve plate 200 is closed, the gas in the groove 120 is compressed to form an air cushion effect, which reduces the impact on the valve seat 100. When the exhaust valve plate 200 is opened, the gas expansion can suppress the impact of the exhaust valve plate 200 on the limiter 300. Through the synergistic effect of the local structural softening of the valve seat 100 and the air cushion buffering effect formed by the gas in the groove 120, the impact stress borne by the exhaust valve plate 200 during high-frequency opening and closing is reduced, thereby effectively alleviating high-cycle fatigue damage caused by repeated impacts, improving the fatigue resistance and service life of the exhaust valve plate 200, and thus enhancing the operational reliability and durability of the upper bearing assembly of the compressor. At the same time, the upper bearing assembly of this invention does not require additional parts; it can be achieved simply by machining the groove 120 on the valve seat 100, offering advantages such as simple structure, convenient processing, and low manufacturing cost.

[0039] In one implementation, please refer to Figure 1The groove 120 is circumferentially arranged around the outer periphery of the exhaust port 110.

[0040] The groove 120 extends continuously along the circumference of the exhaust port 110, forming an annular structure surrounding the exhaust port 110. The groove 120 and the exhaust port 110 are geometrically concentric or nearly concentric, ensuring that during the closing process, the contact area between the free end of the exhaust valve plate 200 and the valve seat 100 is entirely covered by or near the supporting ring surface formed by the annular groove 120, thus providing uniform and consistent flexible support in the circumferential direction. This design of the annular groove 120 avoids stress concentration, uneven wear, or movement misalignment caused by local stiffness differences, making the exhaust valve plate 200 more evenly stressed during high-frequency opening and closing. Furthermore, the annular groove 120 is easily integrally formed using conventional processes such as turning, stamping, or CNC machining, achieving high machining accuracy, eliminating the need for directional assembly, and exhibiting good manufacturing compatibility.

[0041] In another implementation, please refer to Figure 2 Multiple grooves 120 are provided, and the multiple grooves 120 are spaced apart along the circumference of the exhaust port 110. Each groove 120 is arc-shaped and extends along the circumference of the exhaust port 110.

[0042] Multiple grooves 120 are spaced apart along the outer periphery of the exhaust port 110, but each groove 120 extends a certain arc length along the circumference of the exhaust port 110, thus forming a flexible support area of ​​a certain length locally. The solid material bridging area between the spaced grooves 120 can maintain the structural integrity of the valve seat 100, improve its resistance to deformation and long-term service stability, thereby avoiding the problem of excessive weakening of the stiffness or insufficient strength of the valve seat 100 that may be caused by full-circumference slotting, and providing multi-point, directional elastic buffering and air cushion effect in the impact area of ​​the free end of the exhaust valve plate 200. Optionally, the multiple grooves 120 are evenly distributed along the circumference of the exhaust port 110 to ensure that the stress distribution in each part of the groove 120 is uniform when the exhaust valve plate 200 strikes the valve seat 100.

[0043] In one implementation, please refer to Figure 5 The distance from the side edge of the groove 120 away from the central axis of the exhaust port 110 to the central axis of the exhaust port 110 is D. The minimum distance from the bottom of the groove 120 to the side of the valve seat 100 away from the exhaust valve plate 200 is h. h and D satisfy... ;in, p is the maximum difference between the compressor's discharge pressure and suction pressure, σ y The yield stress of the valve seat 100 material.

[0044] During compressor operation, the side of valve seat 100 closest to the discharge valve plate 200 is exposed to the high-pressure discharge chamber and bears the discharge pressure; while the other side of valve seat 100 furthest from the discharge valve plate 200 is typically connected to the suction chamber or low-pressure region and bears the suction pressure. Therefore, valve seat 100 bears a transmembrane pressure load in the thickness direction caused by the pressure difference between the two sides; this pressure difference is... p = p 排气 -p 吸气 Furthermore, the maximum value is taken as the design basis within the entire operating range of the compressor.

[0045] Under this pressure differential, valve seat 100 can be simplified as an annular thin plate structure subjected to a uniformly distributed transverse load, with its critical section typically located near the groove 120 region. According to the bending theory of annular plates in mechanics of materials, the total bending moment M acting at a radius of D (here, the radial distance from the edge of the groove 120 away from the central axis of the exhaust port 110 to the central axis of the exhaust port 110, used to characterize the characteristic radius of the loaded ring) can be obtained by integrating the moment of the pressure about the neutral axis. For a circumferentially uniformly distributed pressure differential load, considering the entire circumference and combining it with the lever arm relationship, the bending moment can be approximately expressed as: .

[0046] Meanwhile, the cross-section of the valve seat 100 in the groove 120 region can be approximated as a section with a width of 2×π×D and a height equal to the remaining wall thickness h, where h is defined as the minimum distance from the bottom of the groove 120 to the end face of the valve seat 100 away from the exhaust valve plate 200, i.e., the effective load-bearing thickness of the valve seat 100 in the groove 120. The flexural section modulus W of this section is: .

[0047] Therefore, the maximum bending stress of the valve seat 100 at this cross-section is: .

[0048] To ensure that the valve seat 100 does not undergo plastic deformation, collapse, or fatigue crack initiation in high-stress areas under long-term alternating loads, the maximum stress must be kept below the yield stress σ of the valve seat 100 material. y That is, the strength condition is satisfied: Among them, the material yield stress σ y The critical stress value used to characterize the transition of a material from the elastic deformation stage to the plastic deformation stage. When the stress on a material is lower than the yield stress, the material only undergoes elastic deformation, meaning that after the external force is removed, the material can completely return to its original shape. When the stress reaches or exceeds the yield stress, the material begins to undergo plastic deformation (permanent deformation), and even if the stress is unloaded, it cannot completely return to its original shape. Establish working pressure difference p, geometric parameters (D, h) of groove 120 and material properties (σ) yThe quantitative relationship between D (arranging the groove 120 further out) and h (deepening the groove 120) is beneficial to improve the buffering effect (reduce local stiffness and enhance the air cushion effect), but will significantly increase the bending stress; conversely, functionality is sacrificed to maintain strength.

[0049] By limiting This design achieves a balance between buffering performance and structural reliability. On one hand, even under extreme compressor operating conditions (such as high pressure ratio and frequent start-stop), the valve seat 100 will not experience localized yielding due to improper groove 120 design, thus maintaining the flatness of the exhaust sealing surface and long-term sealing reliability. On the other hand, by reasonably adjusting the geometric parameters (D, h) of the groove 120, the groove 120 is precisely positioned to act on the impact area of ​​the free end of the exhaust valve plate 200, maximizing the impact energy absorption effect. Furthermore, this relationship organically unifies the material, operating conditions, and geometric parameters of the groove 120, enabling the invented upper bearing assembly to be suitable not only for specific compressor models but also for valve seat 100 designs of different pressure levels and materials (such as cast iron and stainless steel) through parameter substitution, demonstrating good versatility.

[0050] Measurement method for parameter D: Parameter D is defined as the radial distance from the edge of the groove 120 furthest from the central axis of the exhaust port 110 to the central axis of the exhaust port 110, used to characterize the peripheral arrangement of the groove 120 on the valve seat 100. During measurement, first, the actual valve seat 100 or a high-precision sample is placed on the worktable of a coordinate measuring machine (CMM) or optical image measuring instrument; the geometric center of the exhaust port 110 is fitted using its inner bore profile, and the central axis of the exhaust port 110 is determined accordingly. Then, at least four uniformly distributed cross-sections are selected around the groove 120, and the outermost edge point of the groove 120 (i.e., the boundary point farthest from the central axis) in each cross-section is identified, and the horizontal radial distance from each point to the central axis is measured. Finally, the maximum value among all measurements is taken as D to cover the most unfavorable deviation caused by manufacturing tolerances. If the groove 120 is set in multiple segments, the above steps need to be repeated for each segment, and the global maximum D value is taken for strength verification.

[0051] Measurement method of h: The parameter h is defined as the minimum distance from the bottom of the groove 120 to the end face of the valve seat 100 away from the exhaust valve plate 200, reflecting the effective bearing thickness of the valve seat 100 in the groove 120 area. During measurement, the valve seat 100 is first placed stably on the reference platform, with the end face away from the exhaust valve plate 200 as the reference reference surface. Using a depth gauge, laser displacement sensor, or coordinate measuring machine, the groove 120 area is scanned circumferentially and radially to locate the position of the groove bottom closest to the reference surface (corresponding to the minimum h). The straight-line distance from this point along the thickness direction of the valve seat 100 (axial direction of the exhaust port 110) to the reference surface is h. For annular or segmented grooves 120, the local minimum h should be found in all groove segments 120, and the global minimum value among them should be taken as the final h value.

[0052] How to obtain p: parameters p refers to the maximum difference between the discharge pressure and the suction pressure during compressor operation, which is the maximum steady-state pressure differential load acting on valve seat 100. This parameter is usually not obtained by directly measuring a single valve seat 100, but is determined based on the design operating conditions or measured data of the entire compressor. First, consult the compressor's technical specifications or design input documents to obtain its maximum discharge pressure and minimum suction pressure under the most stringent operating conditions (such as the combination of the highest condensing temperature and the lowest evaporating temperature). The difference between the two is p. p. If necessary, a high-precision pressure sensor can be installed on the compressor performance test bench to simultaneously collect data in the exhaust and intake chambers, and record the maximum pressure difference value under steady-state extreme conditions. Note that... p should be taken as the maximum value under steady-state operating conditions, excluding transient impacts or water hammer pressure, as these are used for static bending stress verification. The unit should be consistent with MPa for comparison with the material's yield stress.

[0053] Parameter σ y How to obtain: parameter σ y The yield stress of the valve seat 100 material (σ is the stress for at least a portion of the bearing 10 forming the valve seat 100 in the embodiment). yThe yield stress of the bearing 10 material is a key material performance indicator for determining whether the valve seat 100 has undergone plastic deformation. To obtain this parameter, the specific grade of the material used in the valve seat 100 must first be determined (e.g., HT250 cast iron, SUS304 stainless steel, or a metallurgical material with a specific composition). Then, the minimum yield strength value at room temperature (or operating temperature) should be found according to the relevant material standard. For applications requiring high reliability, samples can be taken from the same batch of valve seat 100 raw materials for tensile testing to measure the yield strength. If the compressor operates at a high temperature, the high-temperature yield strength data at that temperature should be used. In engineering verification, the lower limit value in the material standard or the measured average value should be used, with an appropriate safety margin maintained to ensure a conservative and reliable design.

[0054] In one implementation, please refer to Figure 5 and Figure 6 A transition section is formed between the inner edge of the groove 120 and the edge of the exhaust port 110. The surface of the transition section is cut by a plane extending axially along the exhaust port 110, and the cross section includes a first arc segment 130 protruding toward the exhaust valve plate 200. The inner wall of the groove 120 is cut by a plane extending axially along the exhaust port 110, and the cross section includes a straight segment 121 and a second arc segment 122. The straight segment 121 is located between the first arc segment 130 and the second arc segment 122, and is smoothly connected to the first arc segment 130 and the second arc segment 122.

[0055] A transition section is formed between the inner edge of the groove 120 and the edge of the exhaust port 110. This transition section, facing the side surface of the exhaust valve plate 200, appears as a first arc segment 130 protruding towards the exhaust valve plate 200 in a cross-section taken from a plane extending axially along the exhaust port 110 (i.e., a radial section containing the central axis of the exhaust port 110). Simultaneously, the cross-sectional profile of the inner wall of the groove 120 under the same section plane includes a straight segment 121 and a second arc segment 122, wherein the straight segment 121 is located between the first arc segment 130 and the second arc segment 122, and smoothly connects with both the first arc segment 130 and the second arc segment 122. Smooth connection means that adjacent profile segments have the same tangent direction at the connection point, without any geometric abrupt change. The first arc segment 130 protrudes towards the exhaust valve plate 200, which can provide a gentle pre-contact guide surface in the initial stage of the exhaust valve plate 200 closing, guide the free end of the exhaust valve plate 200 to fit smoothly, avoid hard impact on the edge, and reduce impact acceleration and rebound oscillation.

[0056] The straight segment 121 serves as an intermediate connecting segment. While ensuring that the groove 120 has sufficient depth to form an effective buffer cavity, it also maintains the controllability of local stiffness and prevents excessive flexibility from causing deformation of the valve seat 100. The straight segment 121 also reduces the gradient of local geometric changes in the valve seat 100 to avoid excessive stress concentration caused by structural abrupt changes under high-speed impact or differential pressure load of the exhaust valve plate 200.

[0057] By smoothly connecting the first arc segment 130 and the second arc segment 122 to the straight segment 121 (i.e., tangentially continuous), the risk of geometric discontinuities amplifying local stress and becoming fatigue crack initiation areas caused by right angles, sharp edges, or step transitions at the junction of the exhaust port 110 edge and the groove 120 is reduced. This allows the material thickness and curvature to change continuously along the axial and radial directions, effectively dispersing the load transmission path, reducing the maximum principal stress value, and thus improving the structural reliability of the valve seat 100 under long-term high-frequency impact conditions.

[0058] In other embodiments, the straight segment 121 may be omitted, and the end of the second arc segment 122 near the central axis of the exhaust port 110 may extend to the inner edge of the groove 120, with the first arc segment 130 and the second arc segment 122 directly connected.

[0059] In one implementation, please refer to Figure 5 and Figure 6 The length of the straight segment 121 is t, and the minimum distance from the bottom of the groove 120 to the side of the valve seat 100 away from the exhaust valve plate 200 is h. t and h satisfy: 0.2h≤t≤0.4h.

[0060] t refers to the actual length (i.e., the straight-line distance between the two endpoints of the straight-line segment 121) in the inner wall profile of the groove 120 along its own extension direction on the radial section extending axially along the exhaust port 110. h characterizes the load-bearing capacity of the valve seat 100 in the region corresponding to the groove 120, and t characterizes the distribution ratio of the flexible buffer zone and the rigid support zone. (Under pressure differential...) Under the combined impact of p and the exhaust valve plate 200, the groove 120 region is subjected to complex bending and contact stresses. If t < 0.2h, the straight segment 121 is too short, and the groove 120 is almost entirely composed of the second arc segment 122. The shape change gradient between the first arc segment 130 and the second arc segment 122 is large, resulting in high internal stress in the groove 120 when the valve seat 100 is impacted, which will affect the reliability of the valve seat 100. If t > 0.4h, the straight segment 121 is too long, resulting in excessive rigidity in the middle. Stress concentration will transfer to the connection between the straight segment 121 and the first arc segment 130 and the second arc segment 122, forming a high-cycle fatigue crack initiation. By limiting 0.2h ≤ t ≤ 0.4h, the stress can be smoothly transitioned along the depth direction of the groove 120, avoiding local peaks and improving fatigue resistance.

[0061] In one implementation, please refer to Figure 5 The distance from the side edge of the groove 120 away from the central axis of the exhaust port 110 to the central axis of the exhaust port 110 is D, and the radius of the exhaust port 110 is d. D and d satisfy: 1.75d≤D≤2.8d.

[0062] By limiting the radial position of the groove 120 on the valve seat 100 to 1.75d ≤ D ≤ 2.8d, the range of the radial position is defined. If D is too small (D < 1.75d), the groove 120 will be too close to the exhaust port 110, potentially encroaching on the effective sealing area, affecting the integrity of the sealing line when the exhaust valve plate 200 is closed, and even causing gas leakage. Simultaneously, such a close arrangement will place the groove 120 in a high stress concentration area, weakening its buffering effect. If D is too large (D > 2.8d), the groove 120 will be far from the actual impact area of ​​the free end of the exhaust valve plate 200, resulting in the impact energy not being effectively transferred to the flexible area, significantly reducing the buffering effect. By limiting the range to 1.75d ≤ D ≤ 2.8d, it can be ensured that the groove 120 avoids the main sealing zone while covering the dynamic impact point area of ​​the free end of the exhaust valve plate 200, achieving good impact absorption.

[0063] In one implementation, please refer to Figure 5 The distance between the two opposite sides of the valve seat 100 in the axial direction of the exhaust port 110 is H, the minimum distance from the bottom of the groove 120 to the side of the valve seat 100 away from the exhaust valve plate 200 is h, and the radius of the second arc segment 122 is r. H, h and r satisfy: r≥2(Hh).

[0064] The radius of curvature of the second arc segment 122 of the groove 120 is defined by limiting r to ≥ 2(Hh). Here, (Hh) represents the maximum axial depth (i.e., the maximum depth of the groove 120) from the end face of the valve seat 100 near the exhaust valve plate 200 to the bottom of the groove 120. r ≥ 2(Hh) means that the radius of curvature of the second arc segment 122 is at least twice the depth of the groove 120. A larger r value reduces the curvature gradient in the groove bottom region, avoiding the formation of high stress concentration points due to sharp transitions. Under differential pressure loads and repeated impacts from the valve plate, the groove bottom is one of the areas with the highest bending stress. If a small radius corner exists here, it is highly likely to become a fatigue crack initiation source. By limiting r to ≥ 2(Hh), the groove bottom profile can be ensured to be sufficiently smooth, resulting in a more uniform stress distribution, thereby significantly improving the fatigue life and structural reliability of the valve seat 100.

[0065] In one implementation, please refer to Figure 5 D and d satisfy: 1.75d≤D≤2.8d; and H, h and r satisfy: r≥2(Hh).

[0066] In this embodiment, parameter D and parameter r characterize the radial arrangement position and local curvature characteristics of the groove 120, respectively, and they are not isolated. Increasing D will increase the bending moment on the valve seat 100, thus requiring a larger h to meet the strength requirements. The change in h directly affects the depth (Hh) of the groove 120, thus determining the lower limit of r. By simultaneously limiting D and r, both "accurate positioning" and "structural strength" are ensured, guaranteeing that impact energy is effectively guided to the flexible buffer zone while ensuring that the region itself has sufficient fatigue resistance. Furthermore, under high-cycle fatigue conditions, the optimization of D reduces the macroscopic impact load, and the optimization of r weakens the microscopic stress concentration. The two work together to suppress the accumulation of fatigue damage from both the load input and structural response ends. On the other hand, simultaneously limiting D and r also limits the maximum width between the inner and outer walls of the groove 120, as well as the radial width of the transition section.

[0067] Wherein, when the exhaust port 110 is circular, d is its inner radius; if the exhaust port 110 is irregularly shaped, d is defined as the equivalent radius. H is the total thickness of the valve seat 100, and h is the local minimum residual thickness. When measuring H and h, they should be measured on the same axial path. r can be confirmed by a profilometer or CAD fitting.

[0068] In one implementation, please refer to Figure 3 , Figure 7 and Figure 8 The limiter 300 includes a fixed section 310 and a limiting section 320 distributed along its length direction. The fixed section 310 is mounted on the valve seat 100. The limiting section 320 is disposed at a distance from the exhaust valve plate 200. The side of the limiting section 320 facing the exhaust valve plate 200 includes an arcuate section 321 and a flat section 322 connected in its length direction. The arcuate section 321 is closer to the fixed section 310 than the flat section 322.

[0069] The limiter 300 has a fixed section 310 and a limiting section 320 distributed along its length. The fixed section 310 is fixedly installed on the valve seat 100, serving as the basis for fixing and positioning the limiter 300. The limiting section 320 is opposite to and spaced apart from the exhaust valve plate 200, forming a stop constraint on its free end when the exhaust valve plate 200 is opened.

[0070] The limiting section 320, facing the exhaust valve plate 200, includes a connected arcuate section 321 and a flat section 322 along its length, with the arcuate section 321 closer to the fixed section 310 than the flat section 322. The flat section 322 is located at the free end of the limiter 300, and its position strictly defines the maximum lift height that the free end of the exhaust valve plate 200 can reach, ensuring that the total lift remains constant under all operating conditions. Thus, when the compressor operates at high frequency and high load, the exhaust valve plate 200 has a greater opening and starting energy due to inertia and pressure difference. During the lifting process, its free end will pass over the arcuate section 321 and further contact the flat section 322. Since the flat section 322 is a rigid and straight structure, it can provide a stable and sufficient lift space for the exhaust valve plate 200, allowing the exhaust valve plate 200 to fully open to the design limit position, maintaining sufficient exhaust flow cross-section, and ensuring that compression efficiency and overall machine performance are not limited. The curved section 321 is positioned close to the fixed section 310, and its curvature profile matches the shape of the exhaust valve plate 200 as it naturally bends and rises under low-frequency or light-load conditions. When the kinetic energy of the exhaust valve plate 200 is low, it will first contact the curved section 321 and be flexibly guided and buffered, avoiding direct impact with the rigid stop surface. This effectively reduces the impact speed, rebound vibration, and peak load, thereby reducing the impact speed and force of the exhaust valve plate 200 on the limiter 300 and on the valve seat 100 during its fall, and reducing mechanical noise and vibration. Thus, with the maximum lift rigidly locked by the flat section 322, the actual working lift can be adaptively adjusted between low and high frequencies according to the working conditions. On the one hand, the arc-shaped section 321 reduces the impact stress amplitude between the exhaust valve plate 200 and the limiter 300, reduces mechanical noise, and alleviates high-cycle fatigue damage caused by repeated impacts, thereby improving the service life of the exhaust valve plate 200. On the other hand, the flat section 322 ensures the stability of exhaust flow capacity under high-frequency operating conditions, avoiding increased exhaust resistance or decreased volumetric efficiency due to limited lift. Thus, the design of the limiter 300, which includes the connected arc-shaped section 321 and flat section 322 on its length side facing the exhaust valve plate 200, reduces the load on the exhaust valve plate 200 impacting the limiter 300, thereby reducing the noise from the exhaust valve plate 200 impacting the limiter 300 and improving the fatigue resistance of the exhaust valve plate 200.

[0071] In a test experiment, impact tests were conducted on both the existing limiter and the limiter 300 of this invention to obtain corresponding stress contour maps. Please refer to... Figure 12 ,in, Figure 12 Figure (a) shows the stress cloud diagram of the prior art limiter when it is impacted by the exhaust valve plate. The limiting section of the prior art limiter facing the exhaust valve plate only includes an arc section. When the exhaust valve plate impacts the limiter, the maximum stress value of the limiter is 1668 MPa. Figure 12Image (b) shows the stress cloud diagram of the limiter 300 provided by the present invention when impacted by the exhaust valve plate 200. When the exhaust valve plate 200 of the present invention impacts the limiter 300, the maximum stress value of the limiter 300 is 1533 MPa. Compared with the limiter of the prior art, the maximum stress of the limiter 300 of the present invention is reduced by 8.1%. This illustrates that by designing the side of the limiting segment 320 facing the exhaust valve plate 200 as a connected arc-shaped segment 321 and a flat segment 322, the stress of the limiter 300 when impacted by the exhaust valve plate 200 can be reduced. It is worth mentioning that after providing the groove 120 on the valve seat 100, the stress of the exhaust valve plate 200 impacting the valve seat 100 is reduced by 5.1%.

[0072] Please see Figure 13 The figure shows a comparison of the noise generated by existing limiters and the limiter 300 provided by this invention when applied to a compressor at different operating frequencies. The horizontal axis represents the compressor operating frequency (Hz), and the vertical axis represents the sound pressure level (dB) under the corresponding operating conditions. By designing the side of the limiter segment 320 facing the exhaust valve plate 200 as a connected arc segment 321 and a flat segment 322, the noise generated by the limiter 300 when applied to the compressor decreases by 2.4dB and 1.1dB at 90Hz and 120Hz speeds, respectively. This indicates that the structural design effectively improves the dynamic contact characteristics between the exhaust valve plate 200 and the limiter 300, suppressing mechanical impact noise, especially under low-to-medium frequency operating conditions.

[0073] Specifically, the noise reduction amplitude of 2.4 dB (90 Hz) indicates that at relatively low operating frequencies, the exhaust valve plate 200 has low kinetic energy, and its opening process is mainly guided and buffered by the arc-shaped section 321. Because the arc-shaped section 321 matches the natural curvature of the valve plate, the contact process is smooth and the impact force is small, significantly reducing the transient vibration and sound energy radiation generated when the exhaust valve plate 200 impacts the limiter 300. The noise reduction amplitude of 1.1 dB (120 Hz) indicates that under high-frequency, high-kinetic-energy conditions, although the exhaust valve plate 200 will cross the arc-shaped section 321 and contact the flat section 322, the final impact load is still lower than that of a traditional fully arc-shaped rigid limiter structure because the arc-shaped section 321 has absorbed some of the initial impact energy, thus achieving continuous noise reduction.

[0074] In one implementation, please refer to Figure 7 The arc segment 321 and the plane segment 322 are tangent, and the central axis of the exhaust port 110 passes through the point of tangency between the arc segment 321 and the plane segment 322.

[0075] By making the arc segment 321 and the flat segment 322 geometrically tangent at the connection point, the abrupt angle change or contour discontinuity between them is eliminated, thereby forming a smooth and continuous transition curve on the side of the limiting segment 320 facing the exhaust valve plate 200. This smooth transition reduces the local impact, vibration, or motion resistance caused by the abrupt change in the shape of the contact surface during the lifting process of the exhaust valve plate 200, ensuring that it can complete the opening action smoothly and stably.

[0076] Specifically, when the exhaust valve plate 200 moves upward under the action of pressure difference and comes into contact with the limiting section 320, if there is a sharp corner or step between the arc section 321 and the plane section 322, the free end of the exhaust valve plate 200 will experience an instantaneous acceleration change when crossing the boundary, which will cause micro-impact and stress concentration. Long-term accumulation can easily lead to high-cycle fatigue cracks. However, after the arc section 321 and the plane section 322 are tangentially connected, the exhaust valve plate 200 can slide smoothly along the continuous curved surface, avoid sudden changes in dynamic load, effectively suppress the fluctuation of stress amplitude, thereby reducing the risk of fatigue damage and extending the service life.

[0077] Furthermore, the central axis of the exhaust port 110 passes through this tangent point, further ensuring that the smooth transition area is precisely located on the symmetrical center path of the exhaust valve plate 200's movement. The exhaust valve plate 200 typically reciprocates opening and closing with the central axis of the exhaust port 110 as a reference. Its central area bears the main deformation and contact loads. Placing the tangent point here allows the exhaust valve plate 200 to maintain a good contact with the limiting section 320 under all operating conditions, avoiding problems such as uneven load, uneven wear, or asymmetrical lift, and further improving the reliability of the exhaust valve plate 200's movement.

[0078] In one implementation, please refer to Figure 8 and Figure 9 In the cross-section of the limiter 300 cut by a reference surface, the intersection point of the extension line of the arc segment 321 and the end face of the limiter segment 320 away from the fixed segment 310 is denoted as m; the intersection point of the plane segment 322 and the end face of the limiter segment 320 away from the fixed segment 310 is denoted as n; the distance from intersection point m to intersection point n is a; and the maximum lift height of the exhaust valve plate 200 is R. H a and R H Satisfy: a / R H <6%; wherein, the reference plane is a plane that includes the centerline of the limiter 300 in its length direction and is parallel to the central axis of the exhaust port 110.

[0079] In the cross-section of the limiter 300 obtained by a reference plane (defined as a plane containing the centerline of the limiter 300 in its length direction and parallel to the central axis of the exhaust port 110), the intersection point of the extension of the arc segment 321 and the end face of the limiter segment 320 away from the fixed segment 310 is denoted as m, the intersection point of the planar segment 322 and the same end face is denoted as n, and the distance between the two intersection points is defined as a. R H This indicates the maximum lift height that the exhaust valve plate 200 is allowed to reach under normal operating conditions (i.e., the maximum displacement of the free end of the valve plate from the closed position to the fully open position). When the exhaust valve plate 200 closes the exhaust port 110, the distance from the point of tangency between the arc segment 321 and the plane segment 322 along the central axis of the exhaust port 110 to the side of the exhaust valve plate 200 facing the limiter 300 is the maximum lift height R of the exhaust valve plate 200. H .

[0080] 'a' reflects the "extension deviation" in the lift direction of the transition area from the arc section 321 to the flat section 322. If 'a' is too large, it indicates that the arc section 321 deviates significantly from the flat section 322 when approaching the end of the limit section 320. This may cause the exhaust valve plate 200 to fail to reach the designed full-open lift R even though it has contacted the limiter 300 under high-frequency and high-kinetic-energy conditions, because the actual stop position is dominated by the arc section 321. H This reduces the effective exhaust flow area, increases flow resistance, and affects compression efficiency; By limiting a / R H <6% means that the projected distance between the arc segment 321 and the flat segment 322 on the limiting end face is very small, not exceeding 6% of the maximum lift. This ensures that the arc segment 321 is sufficiently close to the flat segment 322 near the maximum lift, so that no matter what kind of kinetic energy the exhaust valve plate 200 has to impact the limiter 300, its final stop position will always be very close to the ideal maximum lift R defined by the flat segment 322. H This avoids lift loss due to an excessively long or offset contour transition zone. In other words, the actual lift achieved by the exhaust valve plate 200 differs from the theoretical maximum lift R. H The deviation is negligible, thus ensuring that the compressor has stable exhaust flow capacity under high-frequency operating conditions and avoiding performance degradation due to insufficient lift.

[0081] In one implementation, please refer to Figure 7 and Figure 10 The sum of the length of the planar segment 322 and the arc length of the arc segment 321 is L. x The exhaust valve plate 200 includes a mounting section 210 and a working section 220 distributed along its length. The mounting section 210 is mounted on the valve seat 100, and the working section 220 is movable relative to the valve seat 100. The length of the working section 220 is L. f L f With L xSatisfy: 0≤L f -L x <0.023L f The limiter 300 is formed by a reference plane that includes the centerline of the limiter 300 in its length direction and is parallel to the central axis of the exhaust port 110. A reference line extends along the axial direction of the exhaust port 110 and passes through the center of the arc section 321. The fixing section 310 and the mounting section 210 are located on the same side of the reference line, while the limiter section 320 and the working section 220 are located on the other side of the reference line.

[0082] L x L represents the unfolded length along the surface of the limiting segment 320 from the starting end of the arc segment 321 to the end of the planar segment 322; f This refers to the length of the movable working section 220 in the exhaust valve plate 200, which is a key dimension determining the deformation shape and dynamic response of the exhaust valve plate 200. f -L x >0 means that the working section 220 of the exhaust valve plate 200 is slightly longer than the coverage area of ​​the limiting section 320 of the limiter 300. That is, when the exhaust valve plate 200 rises to the point where it engages with the limiter 300, the free end of the exhaust valve plate 200 protrudes beyond the end face of the free end of the limiter 300. In other words, the portion of the free end of the exhaust valve plate 200 that protrudes beyond the free end of the limiter 300 is the cantilever section of the exhaust valve plate 200. Let K=L f -L x Then the length of the cantilever segment is K.

[0083] If L x ≥L f (That is, if the limiter 300 completely covers or even exceeds the end of the working section 220 of the exhaust valve plate 200), the free end of the exhaust valve plate 200 will be completely limited when it is opened, causing its deformation mode to tend towards rigid translation. However, the exhaust valve plate 200 is essentially an elastic cantilever beam, and its normal operation depends on reasonable bending deformation to achieve sealing and buffering. If the free end is excessively constrained by rigid limiting, it will increase the rebound force when closed, resulting in uneven stress distribution on the sealing surface, thereby inducing high-frequency flutter under high-frequency operating conditions. Therefore, by limiting L... f -L x >0, allowing the exhaust valve plate 200 cantilever section to be in a state without direct limiting, preserving its necessary local flexibility, which is beneficial for achieving smooth closure and good sealing. Of course, in other embodiments, it can also be L. f -L x = 0. At this time, L x =L f That is, the end face of the free end of the exhaust valve plate 200 is flush with the end face of the free end of the limiter 300.

[0084] L f-L x <0.023L f This indicates that the length K of the cantilever section of the exhaust valve plate 200 needs to be controlled within its total length L. f Within 2.3%. If K is too large (e.g., L...) f -L x >0.023L f If the cantilever section is too long, the stress at the free end of the exhaust valve plate 200 will increase dramatically, resulting in a sharp decrease in fatigue life; the cantilever section will warp when open, making it susceptible to vibration due to airflow disturbances, and will experience poor sealing when closed; it will also increase material usage, thereby raising production costs. Therefore, by limiting 0 ≤ L... f -L x <0.023L f This is beneficial for ensuring the stability of the exhaust valve plate 200 movement and its fatigue resistance reliability, while also taking into account the sealing performance and manufacturing robustness of the exhaust valve plate 200.

[0085] In one implementation, please refer to Figure 11 The outer contour of the free end of the limiter 300 includes two third arc segments 323 and a fourth arc segment 324. The two third arc segments 323 are distributed along the width direction of the limiter 300, and the fourth arc segment 324 is located at one end of the length direction of the limiter 300. The two ends of the fourth arc segment 324 are respectively connected to the two third arc segments 323.

[0086] During assembly, operation, or thermal cycling, the free end of the limiter 300 may be subjected to mechanical impacts, airflow impacts, or vibration loads. If a right-angled or sharp-edge structure is used, high stress concentration is easily formed at the end corners, becoming the starting point for fatigue crack initiation. However, the smooth transition contour composed of three arc segments can significantly reduce the local curvature gradient, making the stress distribution more uniform and improving structural durability. Secondly, the smooth front end contour helps guide airflow smoothly around the limiter 300, reducing eddies and flow noise. At the same time, during automated assembly or maintenance, the rounded ends can avoid scratching the exhaust valve plate 200, valve seat 100, or other adjacent components, improving manufacturing and maintenance safety. The two third arc segments 323 are symmetrically distributed along the width direction, ensuring the balance of lateral mechanical properties and preventing the limiter 300 from twisting or swaying during high-frequency vibration due to asymmetrical chamfers. The fourth arc segment 324, as a connecting bridge, not only completes the geometric closure but also undertakes the main frontal buffer function. The radii of the third arc segment 323 and the fourth arc segment 324 can be the same or different.

[0087] In one implementation, please refer to Figure 11 The radius of the third arc segment 323 is R1, and the radius of the fourth arc segment 324 is R2. R1 and R2 satisfy: R2 / R1>1.5.

[0088] According to Hertzian contact theory, under the same load and material conditions, the larger the equivalent radius of curvature of the contact area, the smaller the contact stress. If the free end of the limiter 300 is designed as a single large arc (radius R2), while this can effectively reduce impact stress, it will lead to excessive outward expansion of the end structure. This not only increases material usage and processing costs but may also encroach on the limited internal space of the compressor, affecting the layout of other components. Conversely, if a smaller radius R1 is used throughout the end, the contact stress concentration will be significant, easily leading to microcracks or accelerating fatigue failure.

[0089] This invention employs a combined structure of a third arc segment 323 and a fourth arc segment 324. A larger radius fourth arc segment 324 is positioned at the most prominent point at the front end of the limiter 300 (i.e., the area where the free end of the exhaust valve plate 200 is most likely to impact first). Because it directly bears the main impact load, the larger radius R2 significantly increases the contact area and reduces the peak contact stress. Smaller radius third arc segments 323 are used on both sides of the limiter 300 in the width direction, ensuring a continuous closed profile while avoiding excessive expansion of the overall structure. By limiting R2 / R1 to > 1.5, a sufficiently large curvature advantage is ensured in the front-end main impact area, while the sides only require necessary transitions, thereby achieving a greater stress optimization effect with a smaller structural increment.

[0090] The present invention also proposes a compressor, which includes an upper bearing assembly. The specific structure of the upper bearing assembly is as described in the above embodiments. Since the compressor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0091] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. An upper bearing assembly, used in a compressor, characterized in that, The upper bearing assembly includes: The valve seat is provided with a mounting groove, and the bottom of the mounting groove is provided with an exhaust port; A limiter is installed in the mounting slot; An exhaust valve plate is disposed in the mounting groove and located below the limiter. The free end of the exhaust valve plate covers the exhaust port and can move between the limiter and the exhaust port to open and close the exhaust port. The valve seat has a groove on the side facing the exhaust valve plate, and the groove is located on the outer periphery of the exhaust port.

2. The upper bearing assembly as described in claim 1, characterized in that, The groove is circumferentially disposed around the outer periphery of the exhaust port.

3. The upper bearing assembly as described in claim 1, characterized in that, The groove is provided in multiple ways, and the multiple grooves are distributed at intervals along the circumference of the exhaust port. Each groove is arc-shaped and extends along the circumference of the exhaust port.

4. The upper bearing assembly as described in claim 1, characterized in that, The distance from the side edge of the groove away from the central axis of the exhaust port to the central axis of the exhaust port is D, and the minimum distance from the bottom of the groove to the side of the valve seat away from the exhaust valve plate is h. h and D satisfy... ;in, This is the maximum difference between the discharge pressure and the suction pressure of the compressor. The value is the yield stress of the valve seat material.

5. The upper bearing assembly as described in claim 1, characterized in that, A transition section is formed between the inner edge of the groove and the edge of the exhaust port. The surface of the transition section is cut by a plane extending axially along the exhaust port, and the cross section includes a first arc segment protruding toward the exhaust valve plate. The inner wall of the groove is cut by a plane extending axially along the exhaust port, and the cross section includes a straight segment and a second arc segment. The straight segment is located between the first arc segment and the second arc segment and is smoothly connected to the first arc segment and the second arc segment.

6. The upper bearing assembly as described in claim 5, characterized in that, The length of the straight segment is t, and the minimum distance from the bottom of the groove to the side of the valve seat away from the exhaust valve plate is h. t and h satisfy: 0.2h≤t≤0.4h.

7. The upper bearing assembly as described in claim 5, characterized in that, The distance from the side edge of the groove opening away from the central axis of the exhaust port to the central axis of the exhaust port is D, and the radius of the exhaust port is d. D and d satisfy: 1.75d≤D≤2.8d; And / or, the distance between the two opposite sides of the valve seat in the axial direction of the exhaust port is H, the minimum distance from the bottom of the groove to the side of the valve seat away from the exhaust valve plate is h, the radius of the second arc segment is r, and H, h and r satisfy: r≥2(Hh).

8. The upper bearing assembly as claimed in claim 1, characterized in that, The limiter includes a fixed section and a limiting section distributed along its length direction. The fixed section is mounted on the valve seat, and the limiting section is disposed at a distance from the exhaust valve plate. The side of the limiting section facing the exhaust valve plate includes a connected arcuate section and a planar section along its length direction, and the arcuate section is closer to the fixed section relative to the planar section.

9. The upper bearing assembly as described in claim 8, characterized in that, The arc segment and the planar segment are tangent, and the central axis of the exhaust port passes through the point of tangency between the arc segment and the planar segment.

10. The upper bearing assembly as claimed in claim 8, characterized in that, The intersection point of the extension line of the arc section and the end face of the one end of the limiting section away from the fixed section is marked as m, the intersection point of the plane section and the end face of the one end of the limiting section away from the fixed section is marked as n, the distance from the intersection point m to the intersection point n is a, and the maximum lift height of the exhaust valve plate is R H , a and R H satisfy: a / R H <6%; wherein the reference surface is a plane containing the center line of the limiting stop in the length direction and parallel to the exhaust port central axis.

11. The upper bearing assembly as claimed in claim 8, characterized in that, The sum of the length of the planar segment and the arc length of the arc segment is L. x The exhaust valve plate includes a mounting section and a working section distributed along its length. The mounting section is mounted on the valve seat, and the working section is movable relative to the valve seat. The length of the working section is L. f L f With L x Satisfy: 0≤L f -L x <0.023L f ; The limiter is formed by a cross-section containing the centerline of the limiter in its length direction and parallel to the central axis of the exhaust port. A reference line extends axially along the exhaust port and passes through the center of the arc segment. The fixing segment and the mounting segment are located on the same side of the reference line, and the limiting segment and the working segment are located on the other side of the reference line.

12. The upper bearing assembly as claimed in claim 8, characterized in that, The outer contour of the free end of the limiter includes two third arc segments and one fourth arc segment. The two third arc segments are distributed along the width direction of the limiter. The fourth arc segment is located at one end in the length direction of the limiter, and the two ends of the fourth arc segment are respectively connected to the two third arc segments.

13. The upper bearing assembly as claimed in claim 12, characterized in that, The radius of the third arc segment is R1, and the radius of the fourth arc segment is R2. R1 and R2 satisfy: R2 / R1>1.

5.

14. A compressor, characterized in that, Includes the upper bearing assembly as described in any one of claims 1 to 13.

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