A combined crankshaft and rotary compressor

Abstract

The present invention provides a combined crankshaft and a rotary compressor, which are applicable to a compressor. The compressor includes a cylinder, and an upper cylinder head and a lower cylinder head are provided on the cylinder. At least one of the upper cylinder head and the lower cylinder head is provided with an exhaust hole 10. The combined crankshaft includes a main shaft 6 and an eccentric part 7. A through hole is provided on the eccentric part 7. The eccentric part 7 is sleeved and fastened on the main shaft 6 through the through hole. A piston 8 is further sleeved outside the eccentric part 7. A sealing piece 9 is further provided at one end of the eccentric part 7 facing the exhaust hole 10. The sealing piece 9 is in cooperation with and in close contact with the inner wall of the piston 8. When the compressor operates, the eccentric part 7, the sealing piece 9 and the piston 8 thereon are rotatably arranged in the cylinder. When the sealing piece 9 and the piston 8 move to the position of the exhaust hole 10, the radial widths of the sealing piece 9 and the piston 8 are sufficient to block the exhaust hole 10. The present invention effectively solves the assembly problem of the eccentric part of the combined steel crankshaft and the main shaft, and ensures sealing and prevents leakage.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and more particularly to a combined crankshaft that facilitates assembly and ensures sealing, and a rotary compressor having the same. Background Art

[0002] The existing crankshaft structure, if made into a combined crankshaft (i.e., the eccentric part and the main shaft are separately manufactured, and the eccentric part is sleeved on the main shaft and fastened), has the following problems:

[0003] 1. With the existing size of the eccentric part 1, since the eccentric part 1 does not have enough wall thickness, it is prone to deformation when sleeved on the main shaft, resulting in insufficient pre-tightening force.

[0004] 2. To increase the wall thickness of the eccentric part 1, it is necessary to increase the outer diameter of the eccentric part 1, which will cause leakage. Specifically, as shown in, Figure 1 , 2 protrusions 11 are respectively formed at both axial ends of the eccentric part 1. When the piston 2 is sleeved outside the eccentric part 1, a recess 12 is formed between the piston 2 and the protrusions 11. When the cylinder inhales, one end face of the piston 2 facing the exhaust port 3 of the cylinder needs to cover the exhaust port 3 of the cylinder, that is, it is necessary to ensure that the minimum sealing line length a between the inner circle of the piston 2 and the exhaust port 3 of the cylinder is greater than 0 to prevent leakage. When the outer diameter b of the eccentric part 1 of the crankshaft increases, the inner diameter of the piston 2 has to be correspondingly reduced. At this time, the minimum sealing line length a cannot be guaranteed, and the thickness of the piston 2 cannot completely seal the exhaust port 3 of the cylinder, resulting in leakage.

[0005] In summary, manufacturing a combined crankshaft currently faces the contradiction between the insufficient wall thickness of the eccentric part and the inability to increase the outer diameter of the eccentric part. Summary of the Invention

[0006] Aiming at the problems in the prior art, the purpose of the present invention is to provide a combined crankshaft that solves the assembly problem of the eccentric part and the main shaft of the combined steel crankshaft, and ensures sealing and prevents leakage, and a rotary compressor having the same.

[0007] According to an aspect of the present invention, there is provided a combined crankshaft suitable for a compressor, wherein the compressor includes a cylinder, an upper cylinder head and a lower cylinder head are provided on the cylinder, and at least one of the upper cylinder head and the lower cylinder head is provided with an exhaust hole. The combined crankshaft includes a main shaft and an eccentric part. The eccentric part is provided with a through hole, and the eccentric part is sleeved and fastened on the main shaft through the through hole. A piston is further sleeved outside the eccentric part. A sealing piece is further provided at one end of the eccentric part facing the exhaust hole. The sealing piece is in cooperation with and in close contact with the inner wall of the piston. When the compressor operates, the eccentric part and the sealing piece and the piston thereon can rotate in the cylinder. When the sealing piece and the piston move to the position of the exhaust hole, the width of the sealing piece and the piston in the radial direction is sufficient to block the exhaust hole.

[0008] Preferably, the end face of the end of the sealing piece facing the exhaust hole and the end face of the piston are in the same plane.

[0009] Preferably, the end face of the end of the eccentric part facing the exhaust hole axially protrudes to form a thrust projection, the thrust projection extends in the radial direction from the through hole of the eccentric part, and the radial width is smaller than the maximum outer diameter of the eccentric part, and a recess is formed between the sealing piece and the thrust projection.

[0010] Preferably, the sealing piece is in a ring structure and is disposed around the outer ring of the eccentric part.

[0011] Preferably, the sealing piece is an arc-shaped segment and is disposed on the end face of the side of the eccentric part farthest from the main shaft.

[0012] Preferably, the radian of the sealing piece is greater than the minimum sealing radian, the minimum sealing radian corresponds to an angle of 2β, the crankshaft operating angle is 2θ, and its calculation formula is:

[0013] θ = arccos((X 2 +R 内 2 -R 偏 2 -2R 偏 R 排 ) / (2XR 内 ))

[0014] β = arctan((R 内 sinθ) / ((R 内 cosθ)-X));

[0015] Wherein X is the eccentricity between the eccentric part and the main shaft, R 内 is the radius of the cylinder bore, R 排 is the radius of the exhaust hole, R 偏 is the eccentric radius.

[0016] Preferably, the radius of the eccentric part is R, the eccentricity of the eccentric part is X, and the radius of the main shaft is r, wherein R > X + r.

[0017] Preferably, the cross section of the eccentric part is circular, the distance between the side of the sealing piece close to the main shaft and the center of the cross section of the eccentric part is smaller than the distance between the center of the cross section of the eccentric part and the exhaust hole, and the distance between the side of the sealing piece far from the main shaft and the center of the cross section of the eccentric part is greater than the distance between the center of the cross section of the eccentric part and the exhaust hole.

[0018] Preferably, the main shaft is made of steel.

[0019] Preferably, the eccentric part is made of powder metallurgy, steel material or casting material.

[0020] Preferably, the eccentric part is sleeved on the main shaft by means of cold pressing, hot fitting, welding, riveting or key connection.

[0021] According to another aspect of the present invention, a rotary compressor is provided, including the combined crankshaft as described above.

[0022] The combined crankshaft of the present invention and the rotary compressor having the same solve the assembly problem of the eccentric part and the main shaft of the combined steel crankshaft, and effectively ensure sealing and prevent leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objects and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0024] Figure 1 is a schematic structural diagram of a crankshaft in the prior art;

[0025] Figure 2 is a schematic structural diagram of the outer diameter of a crankshaft in the prior art;

[0026] Figure 3 is a schematic structural diagram of the combined crankshaft of the present invention;

[0027] Figure 4 is a schematic cross-sectional structural diagram of the combined crankshaft of the present invention;

[0028] Figure 5 is a schematic structural diagram of the eccentric part of the combined crankshaft according to Embodiment 1 of the present invention;

[0029] Figure 6 is a schematic structural diagram of the eccentric part of the combined crankshaft according to Embodiment 2 of the present invention;

[0030] Figure 7 is a schematic diagram of the minimum sealing arc of the combined crankshaft of the present invention.

[0031] REFERENCE NUMERALS

[0032] 1 Existing eccentric part

[0033] 11 Existing protrusion

[0034] 12 Existing depression

[0035] 2 Existing piston

[0036] 3 Existing exhaust port

[0037] 6 Main shaft

[0038] 7 Eccentric part

[0039] 71 Thrust projection

[0040] 8 Piston

[0041] 9 Sealing piece

[0042] 10 Exhaust hole Detailed implementation manners

[0043] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. Identical reference numerals in the figures denote identical or similar structures, and thus their repetitive description will be omitted.

[0044] As Figure 3-6 shown, in an embodiment of the present invention, a combined crankshaft and a compressor having the same are provided, preferably a rotary compressor. Among them, the compressor includes a cylinder, and an upper cylinder head and a lower cylinder head are provided on the cylinder. At least one of the upper cylinder head and the lower cylinder head is provided with an exhaust hole 10.

[0045] As Figure 3 and Figure 4 shown, the combined crankshaft includes a main shaft 6 and an eccentric portion 7.

[0046] The eccentric portion 7 is provided with a through hole, and the eccentric portion 7 is sleeved and fastened to the main shaft 6 through the through hole. The through hole is provided at an eccentric position on the eccentric portion 7.

[0047] The outside of the eccentric portion 7 is further sleeved with a piston 8. And it moves in the cylinder along with the eccentric portion 7.

[0048] A sealing piece 9 is further provided at one end of the eccentric portion 7 facing the exhaust hole 10. The sealing piece 9 is in fit and close contact with the inner wall between the sealing piece 9 and the piston 8.

[0049] When the cylinder of the compressor operates, the eccentric portion 7, the sealing piece 9 and the piston 8 thereon are located in the cylinder. When the sealing piece 9 and the piston 8 move to the position of the exhaust hole 10, the radial widths of the sealing piece 9 and the piston 8 are sufficient to block the exhaust hole 10 to prevent leakage.

[0050] The combined crankshaft of the embodiment of the present invention solves the assembly problem of the eccentric portion and the main shaft of the combined steel crankshaft. By adding the sealing piece, the sealing is effectively ensured and the leakage is prevented, so that the combined crankshaft can be manufactured, and the eccentric outer diameter of the crankshaft can be increased as much as possible, and sufficient pre-tightening force on the shaft can be ensured.

[0051] As Figure 3 andFigure 4 As shown in Figure 4 , in an embodiment of the present invention, preferably, the end face of one end of the sealing piece 9 facing the exhaust hole 10 and the end face of the piston 8 are located in the same plane.

[0052] As Figure 5 and Figure 6 As shown in Figure 6 , in an embodiment of the present invention, the end face of one end of the eccentric part 7 facing the exhaust hole 10 axially protrudes to form a thrust projection 71. The thrust projection 71 extends in the radial direction from the through hole of the eccentric part 7, and the radial width is smaller than the maximum outer diameter of the eccentric part. A recess is formed between the sealing piece 9 and the thrust projection 71.

[0053] As Figure 5 As shown in Figure 5 , in an embodiment of the present invention, the sealing piece 9 is of an annular structure and is disposed around the outer circle of the eccentric part 7.

[0054] As Figure 6 As shown in Figure 6 , in an embodiment of the present invention, the sealing piece 9 is an arc-shaped segment and is disposed on the end face of the side of the eccentric part 7 farthest from the main shaft 6.

[0055] As Figure 7 As shown in Figure 7 , in an embodiment of the present invention, the radian of the sealing piece 9 is greater than the minimum sealing radian. The minimum sealing radian corresponds to an angle of 2β, and the crankshaft operating angle is 2θ. The calculation formula is:

[0056] θ = arccos((X 2 +R 内 2 -R 偏 2 -2R 偏 R 排 ) / (2XR 内 ))

[0057] β = arctan((R 内 sinθ) / ((R 内 cosθ)-X));

[0058] Wherein X is the eccentricity between the eccentric part 7 and the main shaft 6, R 内 is the radius of the cylinder inner diameter, R 排 is the radius of the exhaust hole, R 偏 is the eccentric radius.

[0059] In an embodiment of the present invention, preferably, the radius of the eccentric part 7 is R, the eccentricity of the eccentric part 7 is X, and the radius of the main shaft 6 is r. Among them, R > X + r. The present invention ensures that there is sufficient pre-tightening force when the eccentric part is installed on the main shaft. When the eccentric outer diameter is increased, the piston inner diameter must be increased. Increasing the piston inner diameter results in a decrease in the sealing line and leakage. To ensure that the sealing line remains unchanged, the height of the sealing piece is increased to be the same as the height of the piston.

[0060] As shown in Figure 4 the embodiments of the present invention, preferably, the cross-section of the eccentric part 7 is circular. The distance from the surface of the sealing piece 9 close to the main shaft 6 to the center of the cross-section of the eccentric part 7 is less than the distance from the center of the cross-section of the eccentric part 7 to the exhaust hole 10, and the distance from the surface of the sealing piece 9 far from the main shaft 6 to the center of the cross-section of the eccentric part 7 is greater than the distance from the center of the cross-section of the eccentric part 7 to the exhaust hole 10, which ensures the length of the sealing line c and prevents the compressor from leaking.

[0061] In the embodiments of the present invention, preferably, the main shaft 6 is made of steel.

[0062] Preferably, the sealing piece 9 and the eccentric part 7 are integrally formed. Both the eccentric part 7 and the sealing piece 9 are made of powder metallurgy, steel material or casting material.

[0063] Further preferably, the eccentric part 7 is sleeved on the main shaft 6 by means of cold pressing, hot fitting, welding, riveting or key connection.

[0064] The present invention will be described below with specific embodiments:

[0065] Embodiment 1

[0066] As shown in Figure 3-5 the combination type crankshaft and the rotary compressor having the same, preferably a compressor, wherein, the compressor includes a cylinder, and an exhaust hole 10 is provided on the upper cylinder head of the cylinder.

[0067] The combination type crankshaft includes a main shaft 6 and an eccentric part 7. The main shaft 6 is made of steel. The eccentric part 7 is made of powder metallurgy material. The eccentric part 7 is sleeved on the main shaft 6 by means of cold pressing.

[0068] The eccentric part 7 is provided with a through hole, and the eccentric part 7 is sleeved and fastened on the main shaft 6 through the through hole. The through hole is provided at an eccentric position on the eccentric part 7.

[0069] The outside of the eccentric part 7 is further sleeved with a piston 8 and moves in the cylinder along with the eccentric part 7.

[0070] The radius of the eccentric part 7 is R, the eccentricity of the eccentric part 7 is X, and the radius of the main shaft 6 is r, wherein, R>X + r.

[0071] One end of the eccentric part 7 facing the exhaust hole 10 is further provided with a sealing piece 9. The sealing piece 9 is of an annular structure and is disposed around the outer circle of the eccentric part 7. The height of the sealing piece 9 is consistent with the height of the supporting piston 8, and the end surface of one end of the sealing piece 9 facing the exhaust hole 10 is in the same plane as the end surface of the piston 8. The sealing piece 9 is in fit and close contact with the inner wall of the piston 8.

[0072] When the cylinder of the compressor operates, the eccentric part 7, the sealing piece 9 and the piston 8 thereon are located in the cylinder. When the sealing piece 9 and the piston 8 move to the position of the exhaust hole 10, the radial widths of the sealing piece 9 and the piston 8 are sufficient to block the exhaust hole 10 and prevent leakage.

[0073] Embodiment 2

[0074] As Figure 3 、 4 、shown in 6, a combined crankshaft and a rotary compressor having the same, preferably a compressor, wherein the compressor includes a cylinder, and an exhaust hole 10 is provided on the lower cylinder head of the cylinder.

[0075] The combined crankshaft includes a main shaft 6 and an eccentric part 7. The main shaft 6 is made of steel. The eccentric part 7 is made of a casting material. The eccentric part 7 is sleeved on the main shaft 6 by a hot sleeve method.

[0076] The eccentric part 7 is provided with a through hole, and the eccentric part 7 is sleeved and fastened to the main shaft 6 through the through hole. The through hole is provided at an eccentric position on the eccentric part 7.

[0077] A piston 8 is further sleeved outside the eccentric part 7 and moves in the cylinder along with the eccentric part 7.

[0078] The radius of the eccentric part 7 is R, the eccentricity of the eccentric part 7 is X, and the radius of the main shaft 6 is r, wherein R > X + r.

[0079] A sealing piece 9 is further provided at one end of the eccentric part 7 facing the exhaust hole 10. The sealing piece 9 is an arc-shaped segment and is provided on the end face of the side of the eccentric part 7 farthest from the main shaft 6. The height of the sealing piece 9 is the same as the height of the supporting piston 8, and the end face of the end of the sealing piece 9 facing the exhaust hole 10 and the end face of the piston 8 are located in the same plane. The sealing piece 9 is in fit with and in close contact with the inner wall of the piston 8.

[0080] When the cylinder of the compressor operates, the eccentric part 7, the sealing piece 9 and the piston 8 thereon are located in the cylinder. When the sealing piece 9 and the piston 8 move to the position of the exhaust hole 10, the radial widths of the sealing piece 9 and the piston 8 are sufficient to block the exhaust hole 10 and prevent leakage.

[0081] In summary, the combined crankshaft of the embodiment of the present invention and the compressor having the same solve the assembly problem of the eccentric part and the main shaft of the combined steel crankshaft, and ensure sealing and prevent leakage.

[0082] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A combined crankshaft applicable to a compressor, wherein the compressor includes a cylinder, an upper cylinder head and a lower cylinder head are provided on the cylinder, and at least one of the upper cylinder head and the lower cylinder head is provided with an exhaust hole (10). Characterized in that the combined crankshaft includes a main shaft (6) and an eccentric part (7), a through hole is provided on the eccentric part (7), the eccentric part (7) is sleeved and fastened on the main shaft (6) through the through hole, a piston (8) is further sleeved outside the eccentric part (7), and a sealing piece (9) is provided at one end of the eccentric part (7) facing the exhaust hole (10), the sealing piece (9) cooperates with the inner wall of the piston (8) and is in close contact therewith. When the compressor operates, the eccentric part (7) and the sealing piece (9) and the piston (8) thereon can rotate in the cylinder. When the sealing piece (9) and the piston (8) move to the position of the exhaust hole (10), the radial width of the sealing piece (9) and the piston (8) is sufficient to block the exhaust hole (10); the end face of one end of the sealing piece (9) facing the exhaust hole (10) and the end face of the piston (8) are located in the same plane; the sealing piece (9) is an arc segment and is provided on the end face of the side of the eccentric part (7) farthest from the main shaft (6); the radian of the sealing piece (9) is greater than the minimum sealing radian, the minimum sealing radian corresponds to an angle of 2β, and the crankshaft rotation angle is 2θ. The calculation formula is as follows θ = arccos((X 2 + R 内 2 - R 偏 2 - 2R 偏 R 排 ) / (2XR 内 )) β = arctan((R 内 sinθ) / ((R 内 cosθ) - X)); where X is the eccentricity between the eccentric part (7) and the main shaft (6), R 内 is the radius of the inner diameter of the cylinder, R 排 is the radius of the exhaust hole, R 偏 is the eccentric radius.

2. The combined crankshaft according to claim 1 Characterized in that a thrust projection (71) axially protrudes from the end face of one end of the eccentric part (7) facing the exhaust hole (10), the thrust projection (71) extends in the radial direction from the through hole of the eccentric part (7), and the radial width is smaller than the maximum outer diameter of the eccentric part, and a depression is formed between the sealing piece (9) and the thrust projection (71).

3. The combined crankshaft according to claim 1 Characterized in that the sealing piece (9) is an annular structure and is arranged around the outer ring of the eccentric part (7).

4. The combined crankshaft according to claim 1 or 3 Characterized in that the radius of the eccentric part (7) is R, the eccentricity of the eccentric part (7) is X, and the radius of the main shaft (6) is r, wherein R > X + r.

5. The combined crankshaft according to claim 1 Characterized in that the cross section of the eccentric part (7) is circular, the distance between the side of the sealing piece (9) close to the main shaft (6) and the center of the cross section of the eccentric part (7) is smaller than the distance between the center of the cross section of the eccentric part (7) and the exhaust hole (10), and the distance between the side of the sealing piece (9) far from the main shaft (6) and the center of the cross section of the eccentric part (7) is greater than the distance between the center of the cross section of the eccentric part (7) and the exhaust hole (10).

6. The combined crankshaft according to claim 1 Characterized in that the main shaft (6) is made of steel.

7. The combined crankshaft according to claim 1 Characterized in that the eccentric part (7) is made of powder metallurgy, steel material or casting material.

8. The combined crankshaft according to claim 1 It is characterized in that: The eccentric part (7) is sleeved on the main shaft (6) by means of cold pressing, hot shrinking, welding, riveting or key connection.

9. A rotary compressor, It is characterized in that: It includes the combined crankshaft according to any one of claims 1-3, 5-8.

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