CN117662460A - Compression mechanism and rotary refrigerant pump - Google Patents

Abstract

The invention discloses a compression mechanism and a rotary refrigerant pump with the same, wherein the compression mechanism comprises a crankshaft, the crankshaft is provided with an eccentric part, a first connecting part and a second connecting part, and the first connecting part and the second connecting part are respectively positioned at two axial sides of the eccentric part; the upper bearing is provided with an upper matching hole, the upper bearing is sleeved on the first connecting part, a first matching gap is arranged between the first connecting part and the upper matching hole, the first matching gap extends along the axial direction of the first connecting part, and the width of the first matching gap is increased or reduced in the direction from the first connecting part to the second connecting part. According to the compression mechanism disclosed by the invention, when the crankshaft deflects, the local stress concentration of the crankshaft caused by direct contact between the first connecting part and the upper bearing is avoided as much as possible, so that the abrasion between the first connecting part and the upper bearing is reduced, and the friction loss of the compression mechanism is further reduced.

Description

Compression mechanism and rotary refrigerant pump

Technical Field

The invention relates to the technical field of refrigeration, in particular to a compression mechanism and a rotary refrigerant pump.

Background

The compression mechanism is an important constituent structure of the rotary refrigerant pump. When the rotary refrigerant pump works, the upper bearing and the lower bearing for supporting the crankshaft are arranged at the two ends of the eccentric part of the crankshaft, and when the crankshaft rotates, the eccentric part is arranged to enable the crankshaft to be in direct contact with the upper bearing and the lower bearing to cause local stress concentration of the crankshaft, so that friction loss of the compression mechanism is large, and the efficiency of the rotary refrigerant pump is low.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. The invention proposes a compression mechanism which, when the crankshaft is deflected, avoids local stress concentration of the crankshaft caused by direct contact between the first connecting part and the upper bearing as much as possible.

The invention also proposes a rotary refrigerant pump comprising the compression mechanism described above.

A compression mechanism according to an embodiment of the present invention includes: the crankshaft is provided with an eccentric part, a first connecting part and a second connecting part, and the first connecting part and the second connecting part are positioned at two axial sides of the eccentric part; the upper bearing is provided with an upper matching hole, the upper bearing is sleeved on the first connecting part, a first matching gap is formed between the first connecting part and the upper matching hole, the first matching gap extends along the axial direction of the first connecting part, and in the direction from the first connecting part to the second connecting part, the width of the first matching gap is increased or decreased.

According to the compression mechanism disclosed by the embodiment of the invention, the crankshaft is provided with the eccentric part, the first connecting part and the second connecting part are respectively positioned at two axial sides of the eccentric part, the upper bearing is sleeved on the first connecting part, a first fit clearance is arranged between the first connecting part and the upper fit hole, the first fit clearance extends along the axial direction of the first connecting part, and the width of the first fit clearance is increased or reduced in the direction from the first connecting part to the second connecting part, so that the first connecting part and the upper bearing are prevented from being directly contacted to cause local stress concentration of the crankshaft as much as possible when the crankshaft deflects, and meanwhile, a liquid film is easier to form between the first connecting part and the upper fit hole and can maintain enough liquid film thickness, so that abrasion between the first connecting part and the upper bearing is reduced, friction loss of the compression mechanism is further reduced, and energy efficiency of a rotary refrigerant pump applying the compression mechanism is improved. In addition, since friction loss between the first connecting portion and the upper bearing is small when the crankshaft rotates, the compression mechanism and the sealing and reliability are ensured.

According to some embodiments of the invention, the first connecting portion has a first fitting portion, the first fitting portion having an outer wall surface and an inner wall surface of the upper fitting hole defining the first fitting gap therebetween, the first fitting portion having a diameter that decreases or increases in a direction from the first connecting portion to the second connecting portion.

According to some embodiments of the invention, the difference between the maximum radius and the minimum radius of the first mating portion is L1, the maximum diameter of the first connecting portion is D1, and: L1/D1 is more than or equal to 0.0001 and less than or equal to 0.002; or, the difference between the maximum radius and the minimum radius of the first fitting portion is L1, the length of the first fitting portion along the axial direction of the crankshaft is H1, and the following conditions are satisfied: L1/H1 is more than or equal to 0.00007 and less than or equal to 0.001.

According to some embodiments of the invention, the upper mating hole has a first mating hole section, the first mating hole section having an inner wall surface that defines the first mating gap with an outer wall surface of the first connecting portion, and the first mating hole section has a diameter that increases or decreases in a direction from the first connecting portion to the second connecting portion.

According to some embodiments of the invention, the difference between the maximum radius and the minimum radius of the first mating hole segment is L3, the maximum diameter of the first connection portion is D1, and: L3/D1 is more than or equal to 0.0001 and less than or equal to 0.002; or, the difference between the maximum radius and the minimum radius of the first mating hole section is L3, the length of the first mating hole section along the axial direction of the upper bearing is H3, and the following conditions are satisfied: L3/H3 is more than or equal to 0.00007 and less than or equal to 0.001.

According to some embodiments of the invention, a second fit gap is further provided between the first connection portion and the upper fit hole, the second fit gap extending in an axial direction of the first connection portion and being located on a side of the first fit gap away from the second connection portion, the first fit gap increasing in width and the second fit gap decreasing in width in a direction from the first connection portion to the second connection portion.

According to some embodiments of the invention, the first connecting portion has a second mating portion, the second mating portion having an outer wall surface that defines the second mating gap with an inner wall surface of the upper mating hole, the second mating portion having an increasing diameter in a direction from the first connecting portion to the second connecting portion.

According to some embodiments of the invention, the difference between the maximum radius and the minimum radius of the second mating portion is L12, the maximum diameter of the first connecting portion is D1, and: L12/D1 is more than or equal to 0.0001 and less than or equal to 0.002; or, the difference between the maximum radius and the minimum radius of the second fitting portion is L12, the length of the second fitting portion in the axial direction of the crankshaft is H12, and the following conditions are satisfied: L12/H12 is more than or equal to 0.00007 and less than or equal to 0.001.

According to some embodiments of the invention, a distance between an end of the second fitting portion remote from the eccentric portion and a surface of the eccentric portion remote from the second connecting portion is H11, a height of the upper bearing in the axial direction of the crankshaft is Hmb, and it is satisfied that: H11/Hmb is more than or equal to 0.9 and less than or equal to 1.5.

According to some embodiments of the invention, the upper mating hole has a second mating hole section, the second mating hole section having an inner wall surface that defines the second mating gap with an outer wall surface of the first connecting portion, the second mating hole section decreasing in diameter in a direction from the first connecting portion to the second connecting portion.

According to some embodiments of the invention, the difference between the maximum radius and the minimum radius of the second mating hole segment is L32, the maximum diameter of the first connecting portion is D1, and: L32/D1 is more than or equal to 0.0001 and less than or equal to 0.002; or, the difference between the maximum radius and the minimum radius of the second mating hole section is L32, the length of the second mating hole section along the axial direction of the upper bearing is H32, and the following conditions are satisfied: L32/H32 is more than or equal to 0.00007 and less than or equal to 0.001.

According to some embodiments of the invention, the first and second mating gaps are spaced apart in an axial direction of the crankshaft.

According to some embodiments of the invention, further comprising: the lower bearing is provided with a lower matching hole, the lower bearing is sleeved on the second connecting part, a third matching gap is arranged between the second connecting part and the lower matching hole, the third matching gap extends along the axial direction of the second connecting part, and the width of the third matching gap is increased in the direction from the second connecting part to the first connecting part.

According to some embodiments of the invention, the second connecting portion has a third mating portion, the third mating portion having an outer wall surface and an inner wall surface of the lower mating hole defining the third mating gap therebetween, the third mating portion decreasing in diameter in a direction from the second connecting portion to the first connecting portion.

According to some embodiments of the invention, the difference between the maximum radius and the minimum radius of the third mating portion is L2, the maximum diameter of the second connecting portion is D2, and: L2/D2 is more than or equal to 0.0001 and less than or equal to 0.0005; or, the difference between the maximum radius and the minimum radius of the third fitting portion is L2, and the length of the third fitting portion along the axial direction of the crankshaft is H2, and satisfies: L2/H2 is more than or equal to 0.0001 and less than or equal to 0.0005.

According to some embodiments of the invention, the lower mating hole has a third mating hole section, the third mating hole section having an inner wall surface that defines the third mating gap with an outer wall surface of the second connecting portion, the third mating hole section having an increasing diameter in a direction from the second connecting portion to the first connecting portion.

According to some embodiments of the invention, the difference between the maximum radius and the minimum radius of the third mating hole segment is L4, the maximum diameter of the second connecting portion is D2, and: L4/D2 is more than or equal to 0.0001 and less than or equal to 0.0005; or, the difference between the maximum radius and the minimum radius of the third fit hole segment is L4, the length of the third fit hole segment along the axial direction of the lower bearing is H4, and the following conditions are satisfied: L4/H4 is more than or equal to 0.0001 and less than or equal to 0.0005.

According to some embodiments of the invention, the surface of the upper bearing facing the lower bearing has a first annular groove extending in the circumferential direction of the upper mating hole; or, the surface of the lower bearing facing the upper bearing is provided with a second annular groove extending along the circumferential direction of the lower matching hole.

The rotary refrigerant pump according to the embodiment of the invention comprises the compression mechanism.

According to the rotary refrigerant pump provided by the embodiment of the invention, the compression mechanism is arranged, the crankshaft is provided with the eccentric part, the first connecting part and the second connecting part are respectively positioned at two axial sides of the eccentric part, the upper bearing is sleeved on the first connecting part, a first fit clearance is arranged between the first connecting part and the upper fit hole, the first fit clearance extends along the axial direction of the first connecting part, and in the direction from the first connecting part to the second connecting part, the width of the first fit clearance is increased or reduced, so that the local stress concentration of the crankshaft caused by direct contact between the first connecting part and the upper bearing is avoided as much as possible when the crankshaft swings, and meanwhile, a liquid film is easier to form between the first connecting part and the upper fit hole, and the thickness of the liquid film is enough to reduce the abrasion between the first connecting part and the upper bearing, further the friction loss of the compression mechanism is reduced, and the energy efficiency of the rotary refrigerant pump applying the compression mechanism is improved. In addition, since friction loss between the first connecting portion and the upper bearing is small when the crankshaft rotates, the compression mechanism and the sealing and reliability are ensured.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a rotary refrigerant pump according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a crankshaft according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of an upper bearing according to an embodiment of the present invention;

fig. 4 is a cross-sectional view of a lower bearing according to an embodiment of the present invention.

Reference numerals:

1000. a rotary refrigerant pump;

100. a compression mechanism;

1. a crankshaft; 11. a first connection portion; 111. a first mating portion; 112. a second mating portion; 12. a second connecting portion; 121. a third mating portion; 13. a eccentric portion;

2. an upper bearing; 21. an upper mating hole; 211. a first mating bore section; 212. a second mating bore section; 22. a first annular groove;

3. a lower bearing; 31. a lower mating hole; 311. a third mating bore section; 32. a second annular groove;

4. a cylinder; 41. a pump chamber;

5. a piston;

200. and a motor assembly.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, features defining "first", "second" may include one or more such features, either explicitly or implicitly. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

A compression mechanism 100 according to an embodiment of the present invention is described below with reference to the drawings.

As shown in fig. 1 to 4, a compression mechanism 100 according to an embodiment of the present invention includes a crankshaft 1 and an upper bearing 2.

Wherein, the crankshaft 1 has an eccentric portion 13, a first connecting portion 11 and a second connecting portion 12, the first connecting portion 11 and the second connecting portion 12 are located at two axial sides of the eccentric portion 13 respectively, the upper bearing 2 has an upper mating hole 21, the upper bearing 2 is sleeved on the first connecting portion 11, a first mating gap is provided between the first connecting portion 11 and the upper mating hole 21, the first mating gap extends along the axial direction of the first connecting portion 11, and the first mating gap width increases or decreases in the direction from the first connecting portion 11 to the second connecting portion 12.

The first fit clearance is provided around the crankshaft 1, that is, the first fit clearance is formed in a ring shape, and when the compression mechanism 100 is not in operation, the first fit clearance exists between the portion of the outer peripheral wall of the first connecting portion 11 opposite to the first fit clearance and the outer peripheral wall of the upper bearing 2.

When the motor assembly 200 drives the crankshaft 1 to rotate, the crankshaft 1 can deflect in the movement process due to the arrangement of the eccentric part 13, and a first fit clearance is formed between the first connecting part 11 and the upper fit hole 21, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connecting part 11 and the upper bearing 2 when the crankshaft 1 deflects is avoided as much as possible, abrasion of the first connecting part 11 and the upper bearing 2 is reduced, friction loss of the compression mechanism 100 is reduced, and energy efficiency of the rotary refrigerant pump 1000 applying the compression mechanism 100 is improved. Meanwhile, the liquid film is easier to form between the first connecting part 11 and the upper matching hole 21 when the compression mechanism 100 operates through the arrangement of the first matching gap, and enough liquid film thickness can be maintained, so that the lubrication is more effective, the abrasion between the first connecting part 11 and the upper bearing 2 is further reduced, and the friction loss of the compression mechanism 100 is further reduced. In addition, since friction loss between the first connecting portion 11 and the upper bearing 2 is small when the crankshaft 1 rotates, sealability and reliability of the compression mechanism 100 are ensured.

Specifically, the first fit clearance increases in width in the direction of the first connection portion 11 to the second connection portion 12; or the first fit clearance decreases in width in the direction of the first connection portion 11 to the second connection portion 12.

Further, as shown in fig. 1, the compression mechanism 100 further includes a cylinder 4, a piston 5, and a slide sheet. The crankshaft 1 passes through the cylinder 4, the cylinder 4 is provided with a pump cavity 41, the eccentric part 13 is positioned in the pump cavity 41, a liquid inlet hole and a liquid outlet hole which are communicated with the pump cavity 41 are formed in the cylinder 4, a sliding vane groove is formed in the cylinder 4, the piston 5 is sleeved on the outer periphery side of the eccentric part 13 and positioned in the pump cavity 41, the sliding vane is slidably arranged in the sliding vane groove, one end of the sliding vane is always contacted with the piston 5, and the upper bearing 2 is positioned on one axial side of the cylinder 4. It will be appreciated that in the process that the motor assembly 200 drives the crankshaft 1 to drive the piston 5 to rotate, one end of the sliding vane is always in contact with the piston 5, the sliding vane and the piston 5 cooperate to divide the space in the pump cavity 41 into a liquid inlet cavity and a liquid outlet cavity, the liquid inlet hole of the cylinder 4 is communicated with the liquid inlet cavity, and the liquid outlet hole of the cylinder 4 is communicated with the liquid outlet cavity. Wherein, during the rotation of the piston 5, the volumes of the liquid inlet cavity and the liquid outlet cavity are changed, during the volume increase of the liquid inlet cavity, the liquid refrigerant is sucked into the liquid inlet cavity through the liquid inlet hole, during the volume decrease of the liquid outlet cavity, the liquid refrigerant in the liquid outlet cavity is extruded out of the cylinder 4 through the liquid outlet hole, thereby realizing the transportation of the liquid refrigerant by the rotary refrigerant pump 1000 applying the compression mechanism 100.

It should be noted that, the compression mechanism 100 may include one or more cylinders 4, and when the compression mechanism 100 includes one cylinder 4, the crankshaft 1 has an eccentric portion 13 thereon; when the compression mechanism 100 includes a plurality of cylinders 4, the crankshaft 1 has a plurality of eccentric portions 13 thereon in one-to-one correspondence with the plurality of cylinders 4. For example, in fig. 1, the compression mechanism is shown to include two cylinders 4, with the crankshaft 1 having two eccentric portions 13 for illustrative purposes. When the crankshaft 1 has the plurality of eccentric portions 13, the first connecting portion 11 is located above the uppermost eccentric portion 13, and the lower connecting portion 12 is located below the lowermost eccentric portion 13.

According to the compression mechanism 100 of the embodiment of the invention, the crankshaft 1 has the eccentric portion 13, the first connecting portion 11 and the second connecting portion 12, the first connecting portion and the second connecting portion 12 are respectively located at two axial sides of the eccentric portion 13, the upper bearing 2 is sleeved on the first connecting portion 11, a first fit gap is formed between the first connecting portion 11 and the upper fit hole 21, the first fit gap extends along the axial direction of the first connecting portion 11, and in the direction from the first connecting portion 11 to the second connecting portion 12, the width of the first fit gap is increased or decreased, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connecting portion 11 and the upper bearing 2 is avoided as much as possible when the crankshaft 1 is deflected, meanwhile, a liquid film is easier to form between the first connecting portion 11 and the upper fit hole 21, and a sufficient liquid film thickness can be maintained, thereby reducing wear between the first connecting portion 11 and the upper bearing 2, further reducing friction loss of the compression mechanism 100, and improving energy efficiency of the rotary refrigerant pump 1000 applying the compression mechanism 100. In addition, since friction loss between the first connecting portion 11 and the upper bearing 2 is small when the crankshaft 1 rotates, the compression mechanism 100 and the sealing and reliability are ensured.

In some embodiments of the present invention, as shown in fig. 2, the first connection part 11 has a first fitting part 111, a first fitting gap is defined between an outer wall surface of the first fitting part 111 and an inner wall surface of the upper fitting hole 21, and a diameter of the first fitting part 111 is reduced or increased in a direction from the first connection part 11 to the second connection part 12. It can be understood that the first fit gap is defined between the outer wall surface of the first fitting portion 111 of the first connecting portion 11 and the inner wall surface of the upper fitting hole 21, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connecting portion 11 and the upper bearing 2 when the crankshaft 1 deflects is avoided as much as possible, meanwhile, a liquid film is easier to form between the first connecting portion 11 and the upper fitting hole 21, and a sufficient liquid film thickness can be maintained, so that abrasion of the first connecting portion 11 is reduced, and friction loss of the compression mechanism 100 is reduced.

Specifically, the first fitting portion 111 is reduced in diameter in the direction of the first connection portion 11 to the second connection portion 12; or the first fitting portion 111 increases in diameter in the direction of the first connection portion 11 to the second connection portion 12; or the diameter of the first matching part 111 increases and then decreases in the direction from the first connecting part 11 to the second connecting part 12; further, the first fitting portion 111 is reduced in width first and then increased in width in the direction from the first connection portion 11 to the second connection portion 12, and so on.

The first engaging portion 111 extends from an end of the first connecting portion 11 near the eccentric portion 13 to an end of the first connecting portion 11 away from the eccentric portion 13; or the first fitting portion 111 is spaced apart from an end of the first connecting portion 11 away from the eccentric portion 13 in the axial direction of the bearing 1; the first fitting portion 111 is spaced apart from an end of the first connecting portion 11 near the eccentric portion 13 in the axial direction of the bearing 1.

In some embodiments of the present invention, as shown in fig. 2, the difference between the maximum radius and the minimum radius of the first fitting portion 111 is L1, the maximum diameter of the first connecting portion 11 is D1, and the following are satisfied: L1/D1 is more than or equal to 0.0001 and less than or equal to 0.002. It is understood that L1/D1 may be 0.0001, 0.0005, 0.001, 0.0015 or 0.0002, and the size of the first mating portion 111 is further defined by the range of L1/D1, so as to define the size of the first mating gap, thereby reducing wear of the first connecting portion 11 and reducing friction loss of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 2, the difference between the maximum radius and the minimum radius of the first fitting portion 111 is L1, the length of the first fitting portion 111 in the axial direction of the crankshaft 1 is H1, and it is satisfied that: L1/H1 is more than or equal to 0.00007 and less than or equal to 0.001. It is understood that L1/H1 may be 0.00007, 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008 or 0.001, and the size of the first mating portion 111 is further defined by the L1/H1 range, thereby defining the size of the first mating gap, thereby reducing wear of the first connecting portion 11 and reducing frictional wear of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 3, the upper mating hole 21 section has a first mating hole section 211, a first mating gap is defined between an inner wall surface of the first mating hole section 211 and an outer wall surface of the first connection portion 11, and a diameter of the first mating hole section 211 increases or decreases in a direction from the first connection portion 11 to the second connection portion 12. It can be understood that the first fit gap is defined between the inner wall surface of the first fit hole section 211 of the upper bearing 2 and the outer wall surface of the first connection portion 11, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connection portion 11 and the upper bearing 2 when the crankshaft 1 deflects is avoided as much as possible, meanwhile, a liquid film is easier to form between the first connection portion 11 and the upper fit hole 21, and a sufficient liquid film thickness can be maintained, so that abrasion of the first connection portion 11 is reduced, and friction loss of the compression mechanism 100 is reduced.

Specifically, the first fitting hole section 211 decreases in diameter in the direction of the first connecting portion 11 to the second connecting portion 12; or the first fitting hole section 211 increases in diameter in the direction of the first connecting portion 11 to the second connecting portion 12; or the diameter of the first matching hole section 211 increases and then decreases in the direction from the first connecting part 11 to the second connecting part 12; further, or the first mating hole section 211 decreases in width first and then increases in the direction of the first connecting portion 11 to the second connecting portion 12, and so on.

In some embodiments of the present invention, as shown in fig. 3, the difference between the maximum radius and the minimum radius of the first mating hole segment 211 is L3, the maximum diameter of the first connection portion 11 is D1, and the following are satisfied: L3/D1 is more than or equal to 0.0001 and less than or equal to 0.002. It is appreciated that L3/D1 may be 0.0001, 0.0005, 0.001, 0.0015, or 0.0002, and that the dimensions of the first mating hole section 211 are further defined by the range of L3/D1, thereby defining the dimensions of the first mating gap, thereby reducing wear of the first connection 11 and reducing frictional wear of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 3, the difference between the maximum radius and the minimum radius of the first fitting hole section 211 is L3, the length of the first fitting hole section 211 in the axial direction of the upper bearing 2 is H3, and it is satisfied that: L3/H3 is more than or equal to 0.00007 and less than or equal to 0.001. It is appreciated that L3/H1 may be 0.00007, 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, or 0.001, and the size of the first mating hole section 211 is further defined by the L3/H1 range, thereby defining the size of the first mating gap, thereby reducing the wear of the first connection 11 and reducing the frictional wear of the compression mechanism 100.

In some embodiments of the present invention, the first connection part 11 has a first fitting part 111, and the upper fitting hole 21 section has a first fitting hole section 211, and a first fitting gap is defined between an outer wall surface of the first fitting part 111 and an inner wall surface of the first fitting hole section 211. Wherein, the difference between the maximum radius and the minimum radius of the first fitting portion 111 is L1, the difference between the maximum radius and the minimum radius of the first fitting hole segment 211 is L3, the maximum diameter of the first connecting portion 11 is D1, and the following conditions are satisfied: by such arrangement, the dimensions of the first fitting portion 111 and the first fitting hole section 211 are further defined, and thus the dimensions of the first fitting gap are defined, thereby reducing wear of the first connection portion 11 and friction loss of the compression mechanism 100.

Further, the difference between the maximum radius and the minimum radius of the first fitting portion 111 is L1, the difference between the maximum radius and the minimum radius of the first fitting hole segment 211 is L3, the length of the first fitting hole segment 211 along the axial direction of the upper bearing 2 is H3, and the following is satisfied: by such arrangement, the dimensions of the first fitting portion 111 and the first fitting hole section 211 are further defined, thereby defining the dimensions of the first fitting gap, and further reducing wear of the first connection portion 11 and friction loss of the compression mechanism 100, and 0.00007 is less than or equal to L1/h1+l3/h1 is less than or equal to 0.001.

When only the first fit gap is provided between the first connecting portion 11 and the upper fit hole 21, the distance between the end of the first fit portion 111 away from the eccentric portion 13 and the surface of the eccentric portion 13 away from the second connecting portion 12 is H12, and the height of the upper bearing 2 in the axial direction of the crankshaft 1 is Hmb, and satisfies: H12/Hmb is more than or equal to 0.9 and less than or equal to 1.5. It will be appreciated that H12/Hmb may be 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5, and that the height relationship of the upper bearing 2 and the first mating portion 111 is further defined by the H12/Hmb range, thereby further defining the size of the first mating gap, so as to reduce wear of the first connecting portion 11 during operation of the compression mechanism 100 and reduce frictional wear of the compression mechanism 100.

In some embodiments of the present invention, there is a second fit gap between the first connection portion 11 and the upper fit hole 21, the second fit gap extending in the axial direction of the first connection portion 11 and being located on a side of the first fit gap away from the second connection portion 12, the first fit gap width increasing and the second fit gap width decreasing in the direction of the first connection portion 11 to the second connection portion 12. It can be appreciated that, since the upper bearing 2 is located above the eccentric portion 13, when the crankshaft 1 is deflected during movement, both ends of the first connecting portion 11 and the upper bearing 2 are easily worn and worn greatly, so that by setting the first fit gap width to increase in the direction from the first connecting portion 11 to the second connecting portion 12, the second fit gap width is reduced, and further, local stress concentration of the crankshaft 1 caused by direct contact between the first connecting portion 11 and the upper bearing 2 when the compression mechanism 100 is operated is reduced, further, wear generated by the first connecting portion 11 is reduced, friction loss of the compression mechanism 100 is reduced, and energy efficiency of the rotary refrigerant pump 1000 using the compression mechanism 100 is improved.

In some embodiments of the present invention, as shown in fig. 2, the first connection part 11 has a second fitting part 112, a second fitting gap is defined between an outer wall surface of the second fitting part 112 and an inner wall surface of the upper fitting hole 21, and a diameter of the second fitting part 112 increases in a direction from the first connection part 11 to the second connection part 12. It can be understood that the second fit clearance is defined between the outer wall surface of the second fit portion 112 of the first connecting portion 11 and the inner wall surface of the upper fit hole 21, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connecting portion 11 and the upper bearing 2 when the crankshaft 1 is deflected is avoided as much as possible.

In some embodiments of the present invention, as shown in fig. 2, the difference between the maximum radius and the minimum radius of the second fitting portion 112 is L12, the maximum diameter of the first connecting portion 11 is D1, and the following are satisfied: L12/D1 is more than or equal to 0.0001 and less than or equal to 0.002. It is understood that L12/D1 may be 0.0001, 0.0005, 0.001, 0.0015 or 0.0002, and the size of the second mating portion 112 is further defined by the range of L12/D1, so as to define the size of the second mating gap, thereby reducing wear of the first connecting portion 11 and reducing friction loss of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 2, the difference between the maximum radius and the minimum radius of the second fitting portion 112 is L12, the length of the second fitting portion 112 in the axial direction of the crankshaft 1 is H12, and it is satisfied that: L12/H12 is more than or equal to 0.00007 and less than or equal to 0.001. It is understood that L12/H12 may be 0.00007, 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008 or 0.001, and the size of the second mating portion 112 is further defined by the range of L12/H12, thereby defining the size of the second mating gap, thereby reducing the wear of the first connecting portion 11 and reducing the frictional wear of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 2 and 3, a distance between an end of the second fitting portion 112 away from the eccentric portion 13 and a surface of the eccentric portion 13 away from the second connecting portion 12 is H11, a height of the upper bearing 2 in the axial direction of the crankshaft 1 is Hmb, and it is satisfied that: H11/Hmb is more than or equal to 0.9 and less than or equal to 1.5. It will be appreciated that H11/Hmb may be 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5, and the height relationship between the first fit gap and the second fit gap formed between the first connection portion 11 and the upper bearing 2 is further defined by the H11/Hmb range, so as to reduce wear of the first connection portion 11 when the compression mechanism 100 is operated, and reduce friction loss of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 3, the upper mating hole 21 section has a second mating hole section 212, a second mating gap is defined between an inner wall surface of the second mating hole section 212 and an outer wall surface of the first connection portion 11, and a diameter of the second mating hole section 212 decreases in a direction from the first connection portion 11 to the second connection portion 12. It will be appreciated that the second fit gap is defined between the inner wall surface of the second fit hole section 212 of the upper bearing 2 and the outer wall surface of the first connecting portion 11, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connecting portion 11 and the upper bearing 2 when the crankshaft 1 is deflected is avoided as much as possible.

In some embodiments of the present invention, as shown in fig. 3, the difference between the maximum radius and the minimum radius of the second mating hole segment 212 is L32, the maximum diameter of the first connecting portion 11 is D1, and the following are satisfied: L32/D1 is more than or equal to 0.0001 and less than or equal to 0.002. It is appreciated that L32/D1 may be 0.0001, 0.0005, 0.001, 0.0015, or 0.0002, and that the size of the second mating hole segment 212 is further defined by the range of L32/D1, thereby defining the size of the second mating gap, thereby reducing wear of the first connection 11 and reducing frictional wear of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 3, the difference between the maximum radius and the minimum radius of the second mating hole segment 212 is L32, and the length of the second mating hole segment 212 in the axial direction of the upper bearing 2 is H32, and satisfies: L32/H32 is more than or equal to 0.00007 and less than or equal to 0.001. It is appreciated that L32/H32 may be 0.00007, 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, or 0.001, and the size of the second mating hole section 212 is further defined by the range of L32/H32, thereby defining the size of the second mating gap, thereby reducing the wear of the first connection 11 and reducing the frictional wear of the compression mechanism 100.

In some embodiments of the present invention, the first connection portion 11 has a second fitting portion 112, the upper fitting hole 21 section has a second fitting hole section 212, and a second fitting gap is defined between an outer wall surface of the second fitting portion 112 and an inner wall surface of the second fitting hole section 212. Wherein, the difference between the maximum radius and the minimum radius of the second mating portion 112 is L12, the difference between the maximum radius and the minimum radius of the second mating hole segment 212 is L32, the maximum diameter of the first connecting portion 11 is D1, and the following conditions are satisfied: by the arrangement, the dimensions of the second matching part 112 and the second matching hole section 212 are further limited, so that the dimensions of a second matching clearance are limited, abrasion generated by the first connecting part 11 is reduced, and friction loss of the compression mechanism 100 is reduced.

Further, the difference between the maximum radius and the minimum radius of the second fitting portion 112 is L12, the length of the second fitting portion 112 in the axial direction of the crankshaft 1 is H12, the difference between the maximum radius and the minimum radius of the second fitting hole section 212 is L32, the length of the second fitting hole section 212 in the axial direction of the upper bearing 2 is H32, and it is satisfied that: by such arrangement, the dimensions of the second mating portion 112 and the second mating hole section 212 are further defined, thereby defining the dimensions of the second mating gap, thereby reducing wear of the first connection portion 11 and friction wear of the compression mechanism 100.

In some embodiments of the invention, the first and second mating gaps are spaced apart in the axial direction of the bearing, as shown in fig. 2. By such arrangement, the part of the crankshaft 1 or the upper bearing 2 between the first fit clearance and the second fit clearance is not processed to maintain the original size, so that the strength of the crankshaft 1 is not greatly reduced while the friction between the first connecting part 11 and the upper bearing 2 is reduced, the reliability of the compression mechanism 100 is ensured, and the processing speed is increased.

In some embodiments of the present invention, the compression mechanism 100 further includes a lower bearing 3, the lower bearing 3 has a lower mating hole 31, the lower bearing 3 is sleeved with the second connection portion 12, a third mating gap is provided between the second connection portion 12 and the lower mating hole 31, the third mating gap extends along an axial direction of the second connection portion 12, and a width of the third mating gap increases in a direction from the second connection portion 12 to the first connection portion 11. It can be appreciated that, since the eccentric portion 13 is disposed such that the crankshaft 1 swings during movement, a third fit gap with an increased width in the direction from the second connecting portion 12 to the first connecting portion 11 is provided between the second connecting portion 12 and the lower fit hole 31, so that local stress concentration of the crankshaft 1 caused by direct contact between the second connecting portion 12 and the lower bearing 3 when the crankshaft 1 swings is avoided as much as possible, and further abrasion of the second connecting portion 12 is reduced, and meanwhile, a liquid film is easier to be formed between the second connecting portion 12 and the lower fit hole 31 due to the disposition of the third fit gap, and a sufficient liquid film thickness can be maintained, so that lubrication is more effectively performed, further friction loss of the compression mechanism 100 is reduced, and energy efficiency of the rotary refrigerant pump 1000 using the compression mechanism 100 is improved. In addition, since friction loss between the second connecting portion 12 and the lower bearing 3 is small when the crankshaft 1 rotates, sealability and reliability of the compression mechanism 100 are ensured.

In some embodiments of the present invention, as shown in fig. 2, the second connection part 12 has a third fitting part 121, a third fitting gap is defined between an outer wall surface of the third fitting part 121 and an inner wall surface of the lower fitting hole 31, and a diameter of the third fitting part 121 is reduced in a direction from the second connection part 12 to the first connection part 11. It can be understood that the third fit clearance is defined between the outer wall surface of the third fit portion 121 of the second connecting portion 12 and the inner wall surface of the lower fit hole 31, so that local stress concentration of the crankshaft 1 caused by direct contact between the second connecting portion 12 and the lower bearing 3 when the crankshaft 1 is deflected is avoided as much as possible.

In some embodiments of the present invention, as shown in fig. 2, the difference between the maximum radius and the minimum radius of the third fitting portion 121 is L2, the maximum diameter of the second connection portion is D2, and the following are satisfied: L2/D2 is more than or equal to 0.0001 and less than or equal to 0.0005. It is appreciated that L2/D2 may be 0.0001, 0.0005, 0.001, 0.0015, or 0.0002, and the size of the third mating portion 112 is further defined by the range of L2/D2, thereby defining the size of the third mating gap, so as to reduce wear of the second connecting portion 12 and reduce friction loss of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 2, the difference between the maximum radius and the minimum radius of the third fitting portion 121 is L2, the length of the third fitting portion 121 in the axial direction of the crankshaft 1 is H2, and it is satisfied that: L2/H2 is more than or equal to 0.0001 and less than or equal to 0.0005. It is appreciated that L2/H2 may be 0.0001, 0.0005, 0.001, 0.0015 or 0.0002, and the size of the third mating portion 121 is further defined by the L2/H2 range, so as to define the size of the third mating gap, thereby reducing the wear generated by the second connecting portion 12 and reducing the friction loss of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 4, the lower mating hole 31 section has a third mating hole section 311, a third mating gap is defined between an inner wall surface of the third mating hole section 311 and an outer wall surface of the second connection portion 12, and a diameter of the third mating hole section 311 increases in a direction from the second connection portion 12 to the first connection portion 11. It will be appreciated that the third fit gap is defined between the inner wall surface of the third fit hole section 311 of the lower bearing 3 and the outer wall surface of the second connecting portion 12, so that local stress concentration of the crankshaft 1 caused by direct contact between the second connecting portion 12 and the lower bearing 3 when the crankshaft 1 is deflected is avoided as much as possible.

In some embodiments of the present invention, as shown in fig. 4, the difference between the maximum radius and the minimum radius of the third mating hole segment 311 is L4, the maximum diameter of the second connection portion is D2, and the following are satisfied: L4/D2 is more than or equal to 0.0001 and less than or equal to 0.0005. It will be appreciated that 0.0001, 0.0005, 0.001, 0.0015 or 0.0002, the dimensions of the third mating portion 112, and thus the dimensions of the third mating gap, are further defined by the range of L4/D2, thereby reducing wear of the second connecting portion 12 and reducing frictional wear of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 4, the difference between the maximum radius and the minimum radius of the third mating hole segment 311 is L4, the length of the third mating hole segment 311 in the axial direction of the lower bearing 3 is H4, and it is satisfied that: L4/H4 is more than or equal to 0.0001 and less than or equal to 0.0005. It is understood that L4/H4 may be 0.00007, 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008 or 0.001, and the size of the third mating portion 121 is further defined by the range of L4/H4, thereby defining the size of the third mating gap, thereby reducing the wear generated by the second connecting portion 12 and reducing the frictional wear of the compression mechanism 100.

In some embodiments of the present invention, the second connecting portion 12 has a third mating portion 121, the lower mating hole 31 section has a third mating hole section 311, a third mating gap is defined between an outer wall surface of the third mating portion 121 and an inner wall surface of the lower mating hole 31, a difference between a maximum radius and a minimum radius of the third mating portion 121 is L2, a maximum diameter of the second connecting portion is D2, a difference between a maximum radius and a minimum radius of the third mating hole section 311 is L4, and: L2/D2+L4/D2 is more than or equal to 0.0001 and less than or equal to 0.0005. By such arrangement, the dimensions of the third fitting portion 121 and the third fitting hole section 311 are further defined, thereby defining the dimensions of the third fitting gap, thereby reducing wear of the second connecting portion 12 and reducing frictional wear of the compression mechanism 100.

Further, the difference between the maximum radius and the minimum radius of the third fitting portion 121 is L2, the length of the third fitting portion 121 in the axial direction of the crankshaft 1 is H2, the difference between the maximum radius and the minimum radius of the third fitting hole section 311 is L4, the length of the third fitting hole section 311 in the axial direction of the lower bearing 3 is H4, and it is satisfied that: L2/H2+L4/H2 4 is more than or equal to 0.0001 and less than or equal to 0.0005. By such arrangement, the dimensions of the third fitting portion 121 and the third fitting hole section 311 are further defined, thereby defining the dimensions of the third fitting gap, thereby reducing wear of the second connecting portion 12 and reducing frictional wear of the compression mechanism 100.

In some embodiments of the present invention, as shown in fig. 4, the surface of the lower bearing 3 facing the upper bearing 2 has a second annular groove 32 extending in the circumferential direction of the lower fitting hole 31 thereon. By this arrangement, the inner wall of the second annular groove 32 is elastically deformed in a direction away from the crankshaft 1 when the crankshaft 1 is deflected, thereby reducing friction between the second connecting portion 12 and the lower bearing 3, further reducing friction loss of the compression mechanism 100, and improving energy efficiency of the rotary refrigerant pump 1000 to which the compression mechanism 100 is applied. Meanwhile, the arrangement of the second annular groove 32 can also enable a liquid film to be formed between the second connecting portion 12 and the lower matching hole 31 more easily, and further maintain a good lubrication state between the second connecting portion 12 and the lower bearing 3.

In some embodiments of the present invention, as shown in fig. 3, the surface of the upper bearing 2 facing the lower bearing 3 has a first annular groove 22 extending in the circumferential direction of the upper fitting hole 21 thereon. By this arrangement, the inner wall of the first annular groove 22 is elastically deformed in a direction away from the crankshaft 1 when the crankshaft 1 is deflected, thereby reducing friction between the first connecting portion 11 and the upper bearing 2, further reducing friction loss of the compression mechanism 100, and improving energy efficiency of the rotary refrigerant pump 1000 to which the compression mechanism 100 is applied. Meanwhile, the arrangement of the first annular groove 22 can further enable a liquid film to be formed between the first connecting portion 11 and the upper matching hole 21 more easily, and further maintain a good lubrication state between the first connecting portion 11 and the upper bearing 2.

A specific embodiment of a compression mechanism 100 according to an embodiment of the present invention is described in detail below with reference to fig. 1, and is exemplary and intended to be illustrative of the present invention and not to be construed as limiting the invention.

The compression mechanism 100 includes a crankshaft 1, an upper bearing 2, and a lower bearing 3, the crankshaft 1 having an eccentric portion 13, a first connecting portion 11, and a second connecting portion 12, the first connecting portion 11 and the second connecting portion 12 being located on both sides of the eccentric portion 13 in the circumferential direction, respectively. The upper bearing 2 is provided with an upper matching hole 21, the lower bearing 3 is provided with a lower matching hole 31, the upper bearing 2 is sleeved on the first connecting part 11, the lower bearing 3 is sleeved on the second connecting part 12, a first matching gap and a second matching gap are arranged between the first connecting part 11 and the upper matching hole 21, the first matching gap extends along the axial direction of the first connecting part 11, the second matching gap extends along the axial direction of the first connecting part 11 and is positioned on one side of the first matching gap far away from the second connecting part 12, and in the direction from the first connecting part 11 to the second connecting part 12, the width of the first matching gap is gradually increased, and the width of the second matching gap is gradually reduced. The second connecting portion 12 and the lower fitting hole 31 have a third fitting gap therebetween, the third fitting gap extending in the axial direction of the second connecting portion 12, and the third fitting gap width gradually increasing in the direction from the second connecting portion 12 to the first connecting portion 11.

Further, the first connecting portion 11 has a first fitting portion 111 and a second fitting portion 112, a first fitting gap is defined between an outer wall surface of the first fitting portion 111 and an inner wall surface of the upper fitting hole 21, a second fitting gap is defined between an outer wall surface of the second fitting portion 112 and an inner wall surface of the upper fitting hole 21, a diameter of the first fitting portion 111 gradually decreases and a diameter of the second fitting portion 112 gradually increases in a direction from the first connecting portion 11 to the second connecting portion 12. The second connecting portion 12 and the lower fitting hole 31 have a third fitting gap therebetween, the third fitting gap extending in the axial direction of the second connecting portion 12, and the third fitting gap width gradually increasing in the direction from the second connecting portion 12 to the first connecting portion 11.

Further, the difference between the maximum radius and the minimum radius of the first fitting portion 111 is L1, the maximum diameter of the first connecting portion 11 is D1, and the following is satisfied: L1/D1 is more than or equal to 0.0001 and less than or equal to 0.002; the difference between the maximum radius and the minimum radius of the first fitting portion 111 is L1, the length of the first fitting portion 111 in the axial direction of the crankshaft 1 is H1, and satisfies: L1/H1 is more than or equal to 0.00007 and less than or equal to 0.001; the difference between the maximum radius and the minimum radius of the second fitting portion 112 is L12, the maximum diameter of the first connecting portion 11 is D1, and the following is satisfied: L12/D1 is more than or equal to 0.0001 and less than or equal to 0.002; the difference between the maximum radius and the minimum radius of the second fitting portion 112 is L12, the length of the second fitting portion 112 in the axial direction of the crankshaft 1 is H12, and it is satisfied that: L12/H12 is more than or equal to 0.00007 and less than or equal to 0.001; the difference between the maximum radius and the minimum radius of the third fitting portion 121 is L2, the maximum diameter of the second connecting portion is D2, and the following is satisfied: L2/D2 is more than or equal to 0.0001 and less than or equal to 0.0005; the difference between the maximum radius and the minimum radius of the third fitting portion 121 is L2, the length of the third fitting portion 121 in the axial direction of the crankshaft 1 is H2, and it is satisfied that: L2/H2 is more than or equal to 0.0001 and less than or equal to 0.0005.

A rotary refrigerant pump 1000 according to an embodiment of the present invention is described below.

The rotary refrigerant pump 1000 according to an embodiment of the present invention includes the compression mechanism 100 described above.

According to the rotary refrigerant pump 1000 of the embodiment of the invention, the compression mechanism 100 is provided, the crankshaft 1 has the eccentric portion 13, the first connecting portion 11 and the second connecting portion 12 are respectively located at two axial sides of the eccentric portion 13, the upper bearing 2 is sleeved on the first connecting portion 11, the first fit gap extends along the axial direction of the first connecting portion 11 through the first fit gap between the first connecting portion 11 and the upper fit hole 21, and the width of the first fit gap is increased or reduced in the direction from the first connecting portion 11 to the second connecting portion 12, so that local stress concentration of the crankshaft 1 caused by direct contact between the first connecting portion 11 and the upper bearing 2 is avoided as much as possible when the crankshaft 1 is deflected, meanwhile, a liquid film is easier to form between the first connecting portion 11 and the upper fit hole 21, and a sufficient liquid film thickness can be maintained, thereby reducing wear between the first connecting portion 11 and the upper bearing 2, further reducing friction loss of the compression mechanism 100, and improving energy efficiency of the rotary refrigerant pump 1000 applying the compression mechanism 100. In addition, since friction loss between the first connecting portion 11 and the upper bearing 2 is small when the crankshaft 1 rotates, the compression mechanism 100 and the sealing and reliability are ensured.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (19)

1. A compression mechanism, comprising:

the crankshaft is provided with an eccentric part, a first connecting part and a second connecting part, and the first connecting part and the second connecting part are respectively positioned at two axial sides of the eccentric part;

The upper bearing is provided with an upper matching hole, the upper bearing is sleeved on the first connecting part, a first matching gap is formed between the first connecting part and the upper matching hole, the first matching gap extends along the axial direction of the first connecting part, and in the direction from the first connecting part to the second connecting part, the width of the first matching gap is increased or decreased.

2. The compression mechanism of claim 1, wherein the first connecting portion has a first mating portion, the first mating portion having an outer wall surface and an inner wall surface of the upper mating hole defining the first mating gap therebetween, the first mating portion having a diameter that decreases or increases in a direction from the first connecting portion to the second connecting portion.

3. The compression mechanism of claim 2, wherein the difference between the maximum radius and the minimum radius of the first mating portion is L1, the maximum diameter of the first connecting portion is D1, and: L1/D1 is more than or equal to 0.0001 and less than or equal to 0.002;

or, the difference between the maximum radius and the minimum radius of the first fitting portion is L1, the length of the first fitting portion along the axial direction of the crankshaft is H1, and the following conditions are satisfied: L1/H1 is more than or equal to 0.00007 and less than or equal to 0.001.

4. The compression mechanism of claim 1, wherein the upper mating bore has a first mating bore section, the first mating bore section having an inner wall surface defining the first mating gap with an outer wall surface of the first connecting portion, the first mating bore section increasing or decreasing in diameter in a direction from the first connecting portion to the second connecting portion.

5. The compression mechanism of claim 4, wherein the difference between the maximum and minimum radii of the first mating bore segments is L3, the maximum diameter of the first connection is D1, and: L3/D1 is more than or equal to 0.0001 and less than or equal to 0.002;

or, the difference between the maximum radius and the minimum radius of the first mating hole section is L3, the length of the first mating hole section along the axial direction of the upper bearing is H3, and the following conditions are satisfied: L3/H3 is more than or equal to 0.00007 and less than or equal to 0.001.

6. The compression mechanism of claim 1, wherein a second mating gap is further provided between the first connecting portion and the upper mating hole, the second mating gap extending in an axial direction of the first connecting portion and being located on a side of the first mating gap away from the second connecting portion, the first mating gap increasing in width and the second mating gap decreasing in width in a direction from the first connecting portion to the second connecting portion.

7. The compression mechanism of claim 6, wherein the first connecting portion has a second mating portion, the second mating portion having an outer wall surface that defines the second mating gap with an inner wall surface of the upper mating hole, the second mating portion having an increasing diameter in a direction from the first connecting portion to the second connecting portion.

8. The compression mechanism of claim 7, wherein the difference between the maximum and minimum radii of the second mating portion is L12, the maximum diameter of the first connecting portion is D1, and: L12/D1 is more than or equal to 0.0001 and less than or equal to 0.002;

or, the difference between the maximum radius and the minimum radius of the second fitting portion is L12, the length of the second fitting portion in the axial direction of the crankshaft is H12, and the following conditions are satisfied: L12/H12 is more than or equal to 0.00007 and less than or equal to 0.001.

9. The compression mechanism according to claim 7, wherein a distance between an end of the second fitting portion away from the eccentric portion and a surface of the eccentric portion away from the second connecting portion is H11, a height of the upper bearing in the axial direction of the crankshaft is Hmb, and is such that: H11/Hmb is more than or equal to 0.9 and less than or equal to 1.5.

10. The compression mechanism of claim 6, wherein the upper mating bore has a second mating bore section, the second mating bore section having an inner wall surface defining the second mating gap with an outer wall surface of the first connecting portion, the second mating bore section decreasing in diameter in a direction from the first connecting portion to the second connecting portion.

11. The compression mechanism of claim 10, wherein the difference between the maximum and minimum radii of the second mating bore segments is L32, the maximum diameter of the first connection is D1, and: L32/D1 is more than or equal to 0.0001 and less than or equal to 0.002; or, the difference between the maximum radius and the minimum radius of the second mating hole section is L32, the length of the second mating hole section along the axial direction of the upper bearing is H32, and the following conditions are satisfied: L32/H32 is more than or equal to 0.00007 and less than or equal to 0.001.

12. The compression mechanism of claim 6, wherein the first and second mating gaps are spaced apart in an axial direction of the crankshaft.

13. The compression mechanism of claim 1, further comprising:

the lower bearing is provided with a lower matching hole, the lower bearing is sleeved on the second connecting part, a third matching gap is arranged between the second connecting part and the lower matching hole, the third matching gap extends along the axial direction of the second connecting part, and the width of the third matching gap is increased in the direction from the second connecting part to the first connecting part.

14. The compression mechanism of claim 13, wherein the second connection portion has a third mating portion, the third mating portion having an outer wall surface that defines the third mating gap with an inner wall surface of the lower mating hole, the third mating portion having a diameter that decreases in a direction from the second connection portion to the first connection portion.

15. The compression mechanism of claim 14, wherein the difference between the maximum radius and the minimum radius of the third mating portion is L2, the maximum diameter of the second connecting portion is D2, and: L2/D2 is more than or equal to 0.0001 and less than or equal to 0.0005;

or, the difference between the maximum radius and the minimum radius of the third fitting portion is L2, and the length of the third fitting portion along the axial direction of the crankshaft is H2, and satisfies: L2/H2 is more than or equal to 0.0001 and less than or equal to 0.0005.

16. The compression mechanism of claim 13, wherein the lower mating bore has a third mating bore section, the third mating bore section having an inner wall surface defining the third mating gap with an outer wall surface of the second connection portion, the third mating bore section increasing in diameter in a direction from the second connection portion to the first connection portion.

17. The compression mechanism of claim 16, wherein the difference between the maximum and minimum radii of the third mating bore segment is L4, the maximum diameter of the second connection portion is D2, and: L4/D2 is more than or equal to 0.0001 and less than or equal to 0.0005; or, the difference between the maximum radius and the minimum radius of the third fit hole segment is L4, the length of the third fit hole segment along the axial direction of the lower bearing is H4, and the following conditions are satisfied: L4/H4 is more than or equal to 0.0001 and less than or equal to 0.0005.

18. The compression mechanism of claim 13, wherein a surface of the upper bearing facing the lower bearing has a first annular groove extending in a circumferential direction of the upper mating bore thereon;

or, the surface of the lower bearing facing the upper bearing is provided with a second annular groove extending along the circumferential direction of the lower matching hole.

19. A rotary refrigerant pump comprising a compression mechanism according to any one of claims 1-18.