Compressor crankshaft and compressor including the same

Abstract

The present invention provides a compressor crankshaft and a compressor including the same, wherein the crankshaft includes a long axis portion, an eccentric portion and a short axis portion arranged in sequence along the axial direction; the long axis portion is provided with a concave annular groove; an oil circuit connected to an oil pool at the bottom of the compressor is provided inside the crankshaft, and a first oil hole of the oil circuit is provided at the concave annular groove of the long axis portion. The present invention provides a concave annular groove on the long axis portion of the compressor crankshaft, and an oil hole of the oil circuit is provided in the concave annular groove, so that the main bearing and the crankshaft are fully lubricated during the rotation process, thereby reducing the power consumption of the compressor and increasing the service life of the compressor; at the same time, the oil discharge of the compressor is improved, and the oil discharge rate is reduced by 21.4%, thereby avoiding the oil shortage failure of the compressor and improving the reliability of the compressor operation.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and in particular to a compressor crankshaft and a compressor comprising the same. Background Art

[0002] Due to the high speed of variable frequency compressors, it is easy for the oil output rate to be too high at high speed. In addition to affecting the reliability of the compressor pump body when the system oil return is poor, the high oil output rate will also have an adverse effect on the air-conditioning system heat exchanger, which is manifested as oil adhering to the inner wall of the heat exchanger pipe, causing low heat exchange efficiency and not meeting energy-saving requirements.

[0003] At present, the oil output rate of the compressor pump body is mainly controlled by adjusting the pressure and flow rate. The amount of oil mixed into the circulating refrigerant at the end of the compressor pump oil is not well controlled. The existing pump oil holes have the following two forms:

[0004] 1. The crankshaft is a straight-through design, which is penetrated by holes of different diameters, and the position of the small hole is limited by an oil plug or other structure;

[0005] 2. Horizontal oil hole design, the horizontal oil hole is set between the cylinder head and the rotor.

[0006] Although the positions of the oil holes of the above two structures are different, they are both connected to the exhaust side. The oil pumped into the pump body from the oil pool at high speed will not only enter the lubrication system, but the rest will be directly discharged from these two holes into the refrigerant circulation system. Direct sealing may cause excessive back pressure at the top of the oil pump structure and affect the pump oil. Therefore, it is necessary to design an oil hole structure that is directly connected to the lubrication system.

[0007] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0008] In view of the problems in the prior art, the purpose of the present invention is to provide a compressor crankshaft and a compressor including the same, wherein the compressor crankshaft can effectively improve the lubrication effect between the main bearing and the crankshaft during rotation, reduce the power consumption of the compressor, and thus increase the service life and operational reliability of the compressor.

[0009] An embodiment of the present invention provides a compressor crankshaft, the crankshaft comprising a long axis portion, an eccentric portion and a short axis portion arranged in sequence along the axial direction;

[0010] The long axis portion is provided with a concave annular groove;

[0011] An oil path connected to the oil pool at the bottom of the compressor is arranged inside the crankshaft, and a first oil hole of the oil path is arranged at the concave annular groove of the long shaft portion.

[0012] According to an example of the present invention, a tool-retracting groove is provided at a position of the long axis portion close to the eccentric portion;

[0013] The second oil hole of the oil circuit is arranged at the retreat groove.

[0014] An embodiment of the present invention further provides a compressor, comprising the compressor crankshaft as described above.

[0015] According to an example of the present invention, the compressor further includes a main bearing and a secondary bearing;

[0016] The main bearing is located between the motor and the cylinder of the compressor;

[0017] The secondary bearing is located on a side of the eccentric portion of the crankshaft away from the cylinder;

[0018] The main bearing is provided with a journal matched with the compressor crankshaft, and the concave annular groove is located inside the journal.

[0019] According to an example of the present invention, a tool-retracting groove is provided at a position of the long axis portion close to the eccentric portion;

[0020] The second oil hole of the oil circuit is arranged at the retreat groove.

[0021] According to an example of the present invention, the inner diameter of the journal of the main bearing is D1, the outer diameter of the undercut groove is d1, the outer diameter of the concave annular groove is d2, and the inner diameter D1, the outer diameter d1 and the outer diameter d2 satisfy the following relationship:

[0022]

[0023] in,

[0024] h1 is the height of the undercut groove;

[0025] h2 is the height from the tool retreat groove to the concave annular groove;

[0026] h3 is the height of the concave annular groove;

[0027] h4 is the height from the concave annular groove to the end of the journal facing away from the cylinder.

[0028] According to an example of the present invention, the height of the concave annular groove is h3, and the height h3 satisfies the following relationship:

[0029]

[0030] in,

[0031] h1 is the height of the undercut groove;

[0032] h2 is the height from the tool retreat groove to the concave annular groove;

[0033] h4 is the height from the concave annular groove to the end of the journal facing away from the cylinder.

[0034] The present invention provides a concave annular groove on the long axis of the compressor crankshaft, and provides an oil hole of the oil circuit in the concave annular groove, so that the main bearing and the crankshaft are fully lubricated during the rotation process, thereby reducing the power consumption of the compressor and increasing the service life of the compressor; at the same time, the oil output of the compressor is improved, and the oil output rate is reduced by 21.4%, thereby avoiding the oil shortage failure of the compressor and improving the reliability of the compressor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present invention will become more obvious. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic structural diagram of a compressor crankshaft according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the internal structure of a compressor according to an embodiment of the present invention;

[0038] Figure 3 It is a schematic structural diagram of a major axis portion and a journal of a main bearing according to an embodiment of the present invention;

[0039] Figure 4 This is the variation diagram of compressor oil output rate with α;

[0040] Figure 5 The deformation at A and B varies with α;

[0041] Figure 6 It is a curve diagram showing the variation of safety factor with the height of the concave ring groove. DETAILED DESCRIPTION

[0042] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0043] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and their repeated descriptions will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0044] Figure 1 The schematic diagram of the structure of a compressor crankshaft according to an embodiment of the present invention is a diagram of the structure of a compressor crankshaft, which transmits the rotational force of the motor of the compressor to the cylinder to compress the refrigerant.

[0045] Specifically, the compressor crankshaft 100 includes a long axis portion 110, an eccentric portion 120 and a short axis portion 130 arranged in sequence along the axial direction; usually, the long axis portion is coaxial with the short axis portion, and the eccentric portion is not coaxial with the long axis portion and the short axis portion;

[0046] The long axis portion 110 is provided with a concave annular groove 111;

[0047] An oil passage connected to the oil pool at the bottom of the compressor is disposed inside the crankshaft 100 , and a first oil hole 1111 of the oil passage is disposed at the concave annular groove 111 of the long shaft portion 110 .

[0048] The present invention provides a concave annular groove on the long axis of the compressor crankshaft, and provides an oil hole of the oil circuit in the concave annular groove, so that the crankshaft and the main bearing matched therewith are fully lubricated during the rotation process, thereby reducing the power consumption of the compressor and increasing the service life of the compressor. Figure 1 The crankshaft of the embodiment is suitable for a twin-cylinder compressor.

[0049] In some other embodiments, a back-off groove 112 is disposed at a position of the long axis portion 110 close to the eccentric portion 120 ; and the second oil hole 1121 of the oil circuit is disposed at the back-off groove 112 .

[0050] The first oil hole 1111 at the concave annular groove 111 can ensure the lubrication effect between the long axis portion above the concave annular groove and the main bearing, and the second oil hole 1121 at the retreat groove 112 can ensure the lubrication effect between the long axis portion below the concave annular groove and the main bearing.

[0051] Some embodiments of the present invention also provide a compressor, including a compressor crankshaft as described above. Specifically, the compressor body includes a shell (not shown in the figure), a motor and a pump body accommodated in the shell, the pump body includes a main bearing 200, a secondary bearing 300 and a cylinder therebetween, and the shell is also provided with the above-mentioned crankshaft 100, the upper part of the crankshaft is positioned on the central axis of the shell through a support assembly, and the lower part of the crankshaft is passed through the center of the main bearing 200 and the secondary bearing 300, and the main bearing 200 and the secondary bearing 300 support the crankshaft 100 of the compressor so that the entire crankshaft is located at the central axis of the shell. A piston is provided in the compression space formed by the main bearing, the secondary bearing and the cylinder, and the piston is fixed to the crankshaft and rotates synchronously with the crankshaft, and the crankshaft transmits the rotational force of the motor to the cylinder to compress the refrigerant. The rotary compressor can be a single-cylinder, double-cylinder or multi-cylinder compressor.

[0052] Figure 2 This is a schematic diagram of the internal structure of a compressor according to an embodiment of the present invention, and this embodiment is a twin-cylinder compressor.

[0053] The compressor includes a main bearing 200 and a secondary bearing 300;

[0054] The main bearing 200 is located between the motor and the cylinder of the compressor;

[0055] The secondary bearing 300 is located on a side of the eccentric portion 120 of the crankshaft away from the cylinder;

[0056] The main bearing 200 is provided with a journal 210 adapted to the compressor crankshaft, and the concave annular groove 111 is located inside the journal 210 , that is, the first oil hole 1111 of the oil circuit of the crankshaft is also provided inside the journal 210 .

[0057] In this embodiment, a back-off groove 112 is disposed at a position of the long axis portion 110 close to the eccentric portion; and the second oil hole 1121 of the oil circuit is disposed at the back-off groove 112 .

[0058] In the refrigeration cycle of the compressor, in addition to the circulation of refrigerant, a part of the oil in the compressor moves with the refrigerant. The proportion of oil in the total amount of refrigerant and oil during operation is defined as the oil output rate (OCR). Generally, a low oil output rate can effectively avoid the occurrence of oil shortage failure in the compressor and improve the reliability of the compressor operation.

[0059] In order to obtain a better lubrication effect between the long shaft and the journal of the main bearing, the inner diameter of the journal 210 of the main bearing is D1, the outer diameter of the undercut groove 112 of the crankshaft is d1, the outer diameter of the concave annular groove 111 of the crankshaft is d2, and d3 is the outer diameter of the long shaft. Figure 3 As shown, at this time,

[0060] The volume of the gap between the undercut groove 112 and the journal 210 of the main bearing is V1;

[0061] V1=π(D1 2 -d1 2 )h1 / 4, h1 is the height of the undercut groove;

[0062] The volume of the gap between the journal of the main bearing and the recessed groove is V2;

[0063] V2=π(D1 2 -d3 2 )h2 / 4, h2 is the height from the tool retreat groove to the concave annular groove;

[0064] The volume of the gap between the concave annular groove 111 and the journal 210 of the main bearing is V3;

[0065] V3=π(D1 2 -d2 2 )h3 / 4, h3 is the height of the concave annular groove;

[0066] The volume of the clearance from the concave ring groove to the end of the main bearing journal facing away from the cylinder is V4;

[0067] V4=π(D1 2 -d3 2 )h4 / 4, h4 is the height from the concave annular groove to the end of the journal away from the cylinder.

[0068] Since the lubrication of the long axis portion 110 between the undercut groove 112 and the concave annular groove 111 is provided by the second oil hole at the undercut groove, and the lubrication of the long axis portion 110 above the concave annular groove 111 is provided by the first oil hole at the concave annular groove, the oil output rate of the compressor changes with the ratio α of the proportion of V4 in V3 to the proportion of V2 in V1, and α can be expressed as:

[0069]

[0070] The change of compressor oil output rate with α is as follows Figure 4 As shown, the oil output rate of the compressor decreases as α increases. When α≥0.8, the oil output rate can reach the expected target.

[0071] At the same time, due to the arrangement of the concave annular groove 111 and the backing groove 112, the force distribution of the long axis portion of the present invention is changed. Figure 2 A) and the bottom end of the journal (see Figure 2 The local deformation of point B) will also change, that is, the change of α will cause the long shaft and the main bearing journal to move away from the end of the cylinder (see Figure 2A), and the bottom end of the journal (see Figure 2 The local deformation at point B varies with α.

[0072] The deformation at A and B varies with α as shown in Figure 5 As shown in the figure. α is directly related to the position of the ring groove. When the same force is applied to the top and eccentric position of the crankshaft, it is found that the deformation at A first decreases and then increases with the increase of α, and the deformation at B increases with the increase of α. When α approaches 1.2, the deformation at A will approach the minimum value. In order to avoid abnormal wear caused by excessive deformation at B, the upper limit value of α is preferably set to 1.2.

[0073] In view of the above requirements, in some embodiments of the present invention, α is set in the range of 0.8 to 1.2. At this time, the inner diameter D1, the outer diameter d1 and the outer diameter d2 need to satisfy the following relationship:

[0074]

[0075] When the inner diameter D1, the outer diameter d1 and the outer diameter d2 need to satisfy the above relationship, there is a better lubrication effect between the long shaft portion and the journal of the main bearing. At the same time, the local deformation of the long shaft portion and the journal of the main bearing away from the cylinder and the bottom end of the journal can also avoid abnormal wear during operation due to deformation, thereby improving the stability of the compressor and the overall efficiency of the machine.

[0076] In order to ensure the reliability of the operation of the compressor pump body, the present invention limits the height h3 of the concave annular groove.

[0077] Generally, mature compressor models must meet the following requirements: they have passed reliability assessments and are in mass production; they are used in harsh environments, such as tropical and Middle Eastern regions where there is a large temperature difference between indoor and outdoor temperatures. At this time, the operating conditions are high pressure at the compressor exhaust port and a large pressure difference between the exhaust port and the return port. When this type of model is running, the thickness of the oil film between the shaft diameter and the long axis is defined as T0; when a compressor with concave annular grooves of different heights h3 is running, the thickness of the oil film between the shaft diameter and the long axis is T, and at this time, T / T0 is defined as the safety factor.

[0078] For compressors with the same total height H of the main bearing shaft diameter, the safety factors of the concave annular grooves with different heights h3 are different.

[0079] Figure 6 It is a curve diagram showing the change of safety factor with the height of the concave ring groove. It can be understood that the greater the thickness of the oil film between the shaft diameter and the long shaft portion, the higher the lubrication effect between the two, the smaller the amount of wear between the two due to operation, and at the same time, the power consumption of the compressor is reduced and the service life of the compressor is increased.

[0080] In some embodiments, the height h3 of the concave annular groove satisfies the following relationship:

[0081]

[0082] That is, when the ratio of the height h3 of the concave annular groove to the total height H of the shaft diameter of the main bearing is less than or equal to 0.25, the wear between the shaft diameter and the major axis due to operation is less than that of a mature model with severe stress conditions.

[0083] In addition, the test found that the oil discharge of the compressor with the crankshaft of the present invention was significantly improved, and the oil discharge rate was reduced by 21.4%. Therefore, the probability of oil shortage failure of the compressor can be effectively reduced, and the reliability of the compressor operation is improved.

[0084] In summary, the present invention provides a concave annular groove on the long axis of the compressor crankshaft, and provides an oil hole for the oil circuit in the concave annular groove, so that the main bearing and the crankshaft are fully lubricated during the rotation process, thereby reducing the power consumption of the compressor and increasing the service life of the compressor; at the same time, the oil output of the compressor is improved, and the oil output rate is reduced by 21.4%, thereby avoiding the oil shortage failure of the compressor and improving the reliability of the compressor operation.

[0085] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is defined by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices stated in the device claim can also be implemented by one unit or device through software or hardware. It should be understood that the terms "below" or "above", "downward" or "upward" are used to describe the features of the exemplary embodiments with reference to the positions shown in the figures; the words first, second, etc. are used to indicate the names, and do not indicate any particular order.

Claims

1. A compressor, characterized in that: The crankshaft includes a long axis portion, an eccentric portion and a short axis portion which are sequentially arranged in the axial direction; The long axis portion is provided with a concave annular groove; An oil passage connected to the oil pool at the bottom of the compressor is arranged inside the crankshaft, and a first oil hole of the oil passage is arranged at the concave annular groove of the long shaft portion; The compressor also includes a main bearing and a secondary bearing; The main bearing is located between the motor and the cylinder of the compressor; The secondary bearing is located on a side of the eccentric portion of the crankshaft away from the cylinder; The main bearing is provided with a journal adapted to the compressor crankshaft, and the concave annular groove is located inside the journal; A tool-retracting groove is provided at a position of the long axis portion close to the eccentric portion; The second oil hole of the oil circuit is arranged at the retreat groove; The inner diameter of the journal of the main bearing is D1, the outer diameter of the undercut groove is d1, the outer diameter of the concave annular groove is d2, and the inner diameter D1, the outer diameter d1 and the outer diameter d2 satisfy the following relationship: in, h1 is the height of the undercut groove; h2 is the height from the tool retreat groove to the concave annular groove; h3 is the height of the concave annular groove; h4 is the height from the concave annular groove to the end of the journal away from the cylinder; The height of the concave annular groove is h3, and the height h3 satisfies the following relationship:

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