A semi-hermetic scroll compressor

Abstract

The application discloses a semi-sealed scroll compressor, which comprises a frame, a moving scroll and a crankshaft. The crankshaft is pivotally connected to a bearing hole on the frame. A back pressure cavity is formed between the frame, the back surface of the moving scroll and the crankshaft. A damping structure is arranged between the crankshaft and the bearing hole to damp the lubricating oil flowing out of the back pressure cavity. The application controls the flowing rate of the lubricating oil out of the back pressure cavity through the damping structure between the bearing hole and the crankshaft, so as to control the pressure of the back pressure cavity.

Description

Technical Field

[0001] The present invention relates to the technical field of scroll compressors, and in particular to a semi-hermetic scroll compressor. Background Art

[0002] A scroll compressor typically consists of a casing, a fixed scroll, an orbiting scroll, a frame assembly, a back pressure pad, a crankshaft, and a motor. The frame is fixed inside the casing, the fixed scroll is fixed to the frame, and the motor drives the orbiting scroll via the crankshaft, drawing in low-pressure refrigerant gas from the casing and compressing it to high-pressure gas for discharge.

[0003] Currently, to improve volumetric efficiency during compression, most systems employ a floating orbiting scroll structure. This structure creates a backpressure chamber with an intermediate pressure between the housing, the back of the orbiting scroll, and the crankshaft. High-pressure lubricating oil is introduced into the backpressure chamber from the exhaust side through a throttle passage. A discharge hole is provided in the housing. The oil in the backpressure chamber returns through this hole to the low-pressure suction chamber inside the housing, where it is re-inhaled, compressed, and discharged, continuing the cycle. The size of the discharge hole determines the pressure within the backpressure chamber. Typically, the pressure in the backpressure chamber exceeds the axial gas force generated by the orbiting and fixed scrolls during compression, causing the orbiting scroll to float toward the fixed scroll, eliminating the gap between the scroll tooth tips and achieving improved volumetric efficiency. However, to maintain an appropriate pressure in the backpressure chamber, the diameter of the discharge hole in the housing should be limited; it is typically kept as small as possible. Consequently, a small diameter makes the discharge hole susceptible to clogging by impurities such as aluminum shavings, copper shavings, and oil sludge in the system during compressor operation. This causes the back pressure chamber to be too high, thereby increasing the friction loss between the orbiting and fixed scrolls, resulting in increased power consumption of the compressor, decreased efficiency, and increased wear of the orbiting and fixed scroll parts.

[0004] Furthermore, a shaft seal is used to achieve a structural seal between the engine base and the crankshaft. The seal's lip faces the back-pressure chamber, and under pressure, the seal expands both inside and outside, achieving a sealing effect. However, while the seal provides a good seal, it also introduces a certain amount of friction loss. The addition of a seal mounting structure to the engine base complicates the structure and increases costs.

[0005] Furthermore, a tooth top sealing strip structure is added to the top of the movable and fixed scroll plates of the compressor. During operation, the tooth top sealing strip floats under the action of the high-pressure gas in the core. The floating tooth top sealing strip can prevent the gas leakage in the axial gap. In view of the requirements of the working environment of the sealing strip, the sealing strip should have good lubricity. If the sealing strip is subject to abnormal wear due to poor lubrication, and the lack of oil lubrication seal will cause serious axial leakage of the movable and fixed scroll plates, which will reduce the working efficiency of the compressor or even cause failure. At present, the lubrication of the tooth top sealing strip of the fixed scroll plate relies on the groove at the core position of the fixed scroll plate to store oil and lubricate the tooth top sealing strip. However, due to the small gap between the movable and fixed scroll plates, the oil supply of this structure is very limited. Even in high-pressure and harsh working environments, it is impossible to meet the oil demand for the scroll end face seal and the tooth top sealing strip lubrication oil. Summary of the Invention

[0006] The present invention aims to provide a semi-hermetic scroll compressor to mainly solve the above-mentioned problems.

[0007] To achieve the above-mentioned objectives, the present invention discloses a semi-hermetic scroll compressor, comprising a frame, a movable scroll and a crankshaft, wherein the crankshaft is pivotally connected to a bearing hole on the frame, and a back-pressure chamber is formed between the frame, the back surface of the movable scroll and the crankshaft. A damping structure for damping the lubricating oil flowing out of the back-pressure chamber is provided between the crankshaft and the bearing hole. The damping structure between the bearing hole and the crankshaft is used to control the rate at which the lubricating oil flows out of the back-pressure chamber, thereby achieving the purpose of controlling the pressure in the back-pressure chamber.

[0008] Furthermore, the damping structure is a damping groove provided on the outer wall of the crankshaft or the inner wall of the bearing hole, one end of the damping groove is communicated with the back pressure cavity, and the other end is located in the bearing hole.

[0009] Furthermore, the damping groove is provided on the outer wall of the crankshaft, the damping groove is opposite to the inner wall of the bearing hole, and the damping groove is a spiral groove extending in a spiral direction along the circumference of the crankshaft.

[0010] Furthermore, the number of spiral turns of the spiral groove is greater than or equal to one turn.

[0011] Furthermore, the rotation direction of the spiral groove is the same as the rotation direction of the crankshaft so as to generate a thrust for the lubricating oil in the spiral groove to move into the back pressure chamber.

[0012] Furthermore, an annular groove is provided on the crankshaft, the annular groove is communicated with the back pressure chamber, and one end of the spiral groove is communicated with the annular groove.

[0013] Furthermore, it also includes a fixed scroll that cooperates with the movable scroll, a sealing groove is provided on one side of the fixed scroll, an oil return hole is provided in the sealing groove, a scroll tooth is provided on the other side of the fixed scroll, a tooth top groove for installing a sealing strip is provided on the top of the scroll tooth, and the fixed scroll is also provided with a sealing strip lubrication channel, one end of the sealing strip lubrication channel is connected to the tooth top groove, and the other end is connected to the oil return hole.

[0014] Furthermore, the sealing strip lubrication channel includes a fixed scroll oil hole and a fixed scroll oil groove, the fixed scroll oil hole axially penetrates the tooth top groove, one end of the fixed scroll oil groove is connected to the oil return hole, and the other end is connected to the fixed scroll oil hole.

[0015] Furthermore, a boss is provided in the sealing groove, the oil return hole is provided at one end of the boss, the fixed scroll oil hole is provided at the other end of the boss, and the fixed scroll oil groove is provided on the upper side of the boss.

[0016] Furthermore, a sealing strip is installed in the tooth top groove, and a sealing strip oil hole is provided in the sealing strip along the axial direction of the fixed scroll.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] The present invention controls the outflow rate of lubricating oil in the back-pressure chamber through the damping structure between the bearing hole and the crankshaft, thereby achieving the purpose of controlling the pressure in the back-pressure chamber. Furthermore, the damping structure is set as a spiral groove on the crankshaft, and the spiral groove applies a resistance to the oil flowing through the bearing gap, and forms an oil film in the bearing gap, which has a good lubrication and sealing effect, so that the pressure in the back-pressure chamber remains stable. At the same time, the oil film also bears part of the shaft load, reduces the load on the main bearing, and increases the service life of the main bearing. At the same time, the setting of the spiral groove also avoids the dirty blockage of the back-pressure chamber discharge channel caused by impurities, and at the same time, there is no friction resistance caused by the shaft seal, which reduces the input work of the compressor and improves efficiency.

[0019] Furthermore, the fixed scroll of the present invention is provided with a sealing strip lubrication channel connecting the tooth top groove and the oil return hole, thereby guiding a portion of the return oil from the oil return hole into the tooth top groove, thereby facilitating full lubrication of the sealing strip in the tooth top groove, thereby reducing the wear of the sealing strip and increasing the service life of the sealing strip; further, the scroll compressor equipped with the fixed scroll can ensure the overall working efficiency of the compressor during operation, thereby increasing the working life of the compressor.

[0020] The present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 is a schematic partial cross-sectional view of the back of a semi-hermetic scroll compressor disclosed in a preferred embodiment of the present invention;

[0023] Figure 2 is an axonometric schematic diagram of a crankshaft of a semi-hermetic scroll compressor disclosed in a preferred embodiment of the present invention;

[0024] Figure 3 1 is a schematic front view of a fixed scroll of a semi-hermetic scroll compressor disclosed in a preferred embodiment of the present invention;

[0025] Figure 4 yes Figure 3 AA cross-sectional view of ;

[0026] Figure 5 yes Figure 3 BB cross-sectional diagram;

[0027] Figure 6 1 is a bottom view schematic diagram of a fixed scroll of a semi-hermetic scroll compressor disclosed in a preferred embodiment of the present invention;

[0028] Figure 7 yes Figure 6 A magnified schematic diagram of .

[0029] Legend:

[0030] 1. Frame; 11. Bearing hole;

[0031] 2. Orbital scroll;

[0032] 3. Crankshaft; 31. Spiral groove; 32. Annular groove;

[0033] 4. Fixed scroll; 41. Seal groove; 42. Oil return hole; 43. Scroll teeth; 44. Tooth top groove; 45. Sealing strip lubrication channel; 451. Fixed scroll oil hole; 452. Fixed scroll oil groove; 46. Boss;

[0034] 5. Housing; 51. Front cover;

[0035] 6. Back pressure chamber;

[0036] 7. Exhaust chamber;

[0037] 9. Motor;

[0038] 10. Sealing strip; 101. Sealing strip oil hole. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0040] like Figure 1-7 As shown, an embodiment of the present invention discloses a semi-hermetic scroll compressor, comprising a frame 1, a movable scroll 2 and a crankshaft 3, and further comprising a fixed scroll 4 cooperating with the movable scroll 2, and a motor 9 driving the crankshaft 3 to rotate, all of which are arranged in a casing 5 of the scroll compressor, and the crankshaft 3 is pivotally connected to a bearing hole 11 on the frame 1, and a back-pressure chamber 6 is formed between the frame 1, the back side of the movable scroll 2 and the crankshaft 3, and an exhaust chamber 7 is formed between the front cover 51 of the casing 5 and the fixed scroll 4, and the exhaust chamber 7 and the back-pressure chamber 6 are connected to each other through an oil return hole 42, so that the high-pressure lubricating oil in the exhaust chamber 7 is introduced into the back-pressure chamber 6, and a damping structure is provided between the crankshaft 3 and the bearing hole 11 for damping the lubricating oil flowing out of the back-pressure chamber 6 to between the crankshaft 3 and the bearing hole 11. The damping structure can be a hole structure, a groove structure or other various forms, so that the outflow rate of the lubricating oil in the back-pressure chamber 6 can be controlled by the damping structure, thereby achieving the purpose of controlling the pressure of the back-pressure chamber 6.

[0041] The damping structure is a damping groove provided on the outer wall of the crankshaft 3 or the inner wall of the bearing hole 11. One end of the damping groove is connected to the back pressure chamber 6, and the other end is located in the bearing hole 11. Figure 1 , that is, the axial length of the damping groove is shorter than the axial length of the bearing hole 11, and one end of the damping groove reaches the edge of the right end of the bearing hole 11, but the other end does not reach the edge of the left end of the bearing hole 11. The damping groove can be of various structural forms, such as a straight groove, a curved groove, etc. In this embodiment, in order to facilitate processing, the damping groove is provided on the outer wall of the crankshaft 3, and the damping groove is opposite to the inner wall of the bearing hole 11. Furthermore, the damping groove is a spiral groove 31 extending along the circumferential spiral of the crankshaft 3, so that it can be completed by a single turning process.

[0042] In this embodiment, the number of spiral turns of the spiral groove 31 is greater than or equal to one turn, usually one turn, so that it can play a sealing role similar to a shaft seal. If it is less than one turn, a complete sealing ring cannot be formed in the circumferential direction of the crankshaft 3, and the sealing effect cannot be achieved.

[0043] In this embodiment, the rotation direction of the spiral groove 31 is set to generate a thrust for the lubricating oil in the spiral groove 31 to move into the back pressure chamber 6 when the crankshaft 3 rotates. Specifically, looking at the crank side of the crankshaft 3, if the crankshaft 3 rotates counterclockwise, the spiral groove 31 is left-handed, and if the crankshaft 3 rotates clockwise, the spiral groove 31 is right-handed. This produces a damping effect on the outflowing oil, controls the speed at which the oil flows out of the back pressure chamber 6, and achieves the purpose of controlling the pressure of the back pressure chamber 6.

[0044] In this embodiment, an annular groove 32 is provided on the crankshaft 3, and the annular groove 32 is connected to the back pressure chamber 6. One end of the spiral groove 31 is connected to the annular groove 32, thereby avoiding the oil inlet end of the damping groove from being blocked. On the other hand, from the perspective of processing technology, it is convenient to retract the tool when turning the thread, and it can also serve as the starting end position for processing the spiral groove 31.

[0045] In this embodiment, a fixed scroll 4 is included, and the fixed scroll 4 and the movable scroll 2 form a compression chamber. A sealing groove 41 is provided on one side of the fixed scroll 4, and the sealing groove 41 is used to install a seal. The sealing groove 41 is arranged in an annular direction, and an oil return hole 42 is provided in the sealing groove 41. During the operation of the compressor, the oil entering through the front cover filter flows into the oil return hole 42 of the fixed scroll 4. A scroll tooth 43 is provided on the other side of the fixed scroll 4, which is used to cooperate with the movable scroll 2 to compress air. A tooth top groove 44 for installing a sealing strip 10 is provided on the top of the scroll tooth 43, which is usually a rectangular groove. The fixed scroll 4 is also provided with a sealing strip lubrication channel 45, and one end of the sealing strip lubrication channel 45 is connected to the tooth top groove 44, and the other end is connected to the oil return hole 42. By providing a sealing strip lubrication channel 45 connecting the tooth top groove 44 and the oil return hole 42, a portion of the oil returned from the oil return hole 42 is directed into the tooth top groove 44, thereby facilitating sufficient lubrication of the sealing strip in the tooth top groove 44, thereby reducing wear on the sealing strip 10 and increasing the service life of the sealing strip 10.

[0046] In this embodiment, when the sealing strip lubrication channel 45 is specifically formed, the sealing strip lubrication channel 45 is divided into two sections, axial and radial, including a fixed scroll oil hole 451 and a fixed scroll oil groove 452, which are formed by machining or casting. The fixed scroll oil hole 451 axially penetrates the tooth top groove 44, and one end of the fixed scroll oil groove 452 is connected to the oil return hole 42, and the other end is connected to the fixed scroll oil hole 451.

[0047] In this embodiment, in order to prevent the seal in the sealing groove 41 from clogging the return oil hole 42, the fixed scroll oil hole 451 and the fixed scroll oil groove 452, a boss 46 is provided in the sealing groove 41. The boss 46 is cast in one piece. The boss 46 runs along the length of the sealing groove 41 and is arranged in the middle of the width direction of the sealing groove 41, so as to facilitate the arrangement of seals around the boss 46. The return oil hole 42 is arranged at one end of the boss 46, the fixed scroll oil hole 451 is arranged at the other end of the boss 46, and the fixed scroll oil groove 452 is arranged on the upper side of the boss 46, so that the input ports of the return oil hole 42, the fixed scroll oil hole 451 and the fixed scroll oil groove 452 are raised to achieve better sealing.

[0048] In this embodiment, in order to facilitate the lubricating oil flowing out of the fixed scroll oil hole 451 to spread evenly to both ends along the tooth top groove 44, the end of the fixed scroll oil hole 451 connected to the tooth top groove 44 is set in the middle position of the tooth top groove 44 in the length direction.

[0049] In this embodiment, a sealing strip 10 is installed in the tooth top groove 44, and a sealing strip oil hole 101 is provided in the sealing strip 10 along the axial direction of the fixed scroll, so that the lubricating oil at the bottom of the tooth top groove 44 can flow to the contact surface of the sealing strip 10 and the movable scroll through the sealing strip oil hole 101. In addition, since the sealing strip 10 is fully lubricated, the working efficiency of the compressor is guaranteed and the working life of the compressor is improved. In order to facilitate the lubricating oil flowing out of the sealing strip oil hole 101 to spread evenly to both ends along the tooth top groove 44, the sealing strip oil hole 101 is set in the middle position of the length direction of the sealing strip 10.

[0050] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A semi-hermetic scroll compressor, comprising a frame (1), a movable scroll (2) and a crankshaft (3), wherein the crankshaft (3) is pivotally connected to a bearing hole (11) on the frame (1), and a back pressure chamber (6) is formed between the frame (1), the back surface of the movable scroll (2) and the crankshaft (3), characterized in that: A damping structure for damping the lubricating oil flowing out of the back pressure chamber (6) is provided between the crankshaft (3) and the bearing hole (11); The damping structure comprises a damping groove provided on the outer wall of the crankshaft (3) or the inner wall of the bearing hole (11), one end of the damping groove being in communication with the back pressure chamber (6), the other end of the damping groove being located in the bearing hole (11), and the damping groove extending in a circumferential spiral along the crankshaft (3); When the crankshaft (3) rotates, a thrust is generated on the lubricating oil in the damping groove to move into the back pressure chamber (6).

2. The semi-hermetic scroll compressor according to claim 1, characterized in that: The damping groove is provided on the outer wall of the crankshaft (3), and the damping groove is opposite to the inner wall of the bearing hole (11).

3. The semi-hermetic scroll compressor according to claim 2, characterized in that: The damping groove is a spiral groove (31) extending in a spiral along the circumference of the crankshaft (3), and the number of spiral turns of the spiral groove (31) is greater than or equal to one turn.

4. The semi-hermetic scroll compressor according to claim 3, characterized in that: The rotation direction of the spiral groove (31) is set to generate a thrust for the lubricating oil in the spiral groove (31) to move into the back pressure chamber (6) when the crankshaft (3) rotates.

5. The semi-hermetic scroll compressor according to claim 3, characterized in that: An annular groove (32) is provided on the crankshaft (3), the annular groove (32) is communicated with the back pressure chamber (6), and one end of the spiral groove (31) is communicated with the annular groove (32).

6. The semi-hermetic scroll compressor according to any one of claims 1 to 5, characterized in that: The fixed scroll (4) is matched with the movable scroll (2), wherein a sealing groove (41) is provided on one side of the fixed scroll (4), an oil return hole (42) is provided in the sealing groove (41), a scroll tooth (43) is provided on the other side of the fixed scroll (4), a tooth top groove (44) for mounting a sealing strip (10) is provided on the top of the scroll tooth (43), and a sealing strip lubrication channel (45) is further provided on the fixed scroll (4), one end of the sealing strip lubrication channel (45) is connected to the tooth top groove (44), and the other end is connected to the oil return hole (42).

7. The semi-hermetic scroll compressor according to claim 6, characterized in that: The sealing strip lubrication channel (45) comprises a fixed scroll oil hole (451) and a fixed scroll oil groove (452), wherein the fixed scroll oil hole (451) axially penetrates the tooth top groove (44), and one end of the fixed scroll oil groove (452) is connected to the oil return hole (42), and the other end is connected to the fixed scroll oil hole (451).

8. The semi-hermetic scroll compressor according to claim 7, characterized in that: A boss (46) is provided in the sealing groove (41), the oil return hole (42) is provided at one end of the boss (46), the fixed scroll oil hole (451) is provided at the other end of the boss (46), and the fixed scroll oil groove (452) is provided on the upper side of the boss (46).

9. The semi-hermetic scroll compressor according to claim 7, characterized in that: A sealing strip (10) is installed in the tooth top groove (44), and a sealing strip oil hole (101) is provided in the sealing strip (10) along the axial direction of the fixed scroll (4).

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