Crankshaft structure for compressor and compressor

Abstract

The invention relates to the technical field of compressors, in particular to a crankshaft structure for a compressor and the compressor, the crankshaft structure for the compressor comprises a core part, and the hardness of the core part is H1; and an outer peripheral part formed on the outer periphery of the core part, the hardness of the outer peripheral part being H2, the hardness ratio of the hardness H2 of the outer peripheral part to the hardness H1 of the core part being h, 1.95 < h < 2.22 or 5.6 < = h < = 6.2. The crankshaft structure for the compressor and the compressor can solve the problem of how to improve the wear resistance of the matching part of the crankshaft.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a crankshaft structure for a compressor and a compressor. Background Art

[0002] Compressors with high rotational speeds (above 100 Hz) can achieve substantially the same power output as those with high displacement designs under the condition of a lower displacement structure design, and are smaller in size and lower in cost. Currently, they are widely used in the refrigeration industry.

[0003] However, under high rotational speed conditions, the motor will generate a greater centrifugal force during operation, resulting in wear at the positions where the crankshaft mates with other components of the compressor due to the action of the centrifugal force, thereby affecting the service life of the compressor.

[0004] Currently, the industry generally adopts a technical solution of adding or improving the lubricating oil passage on the crankshaft to enhance the lubrication effect of the bearing part. However, this solution not only increases the design cost but also significantly improves the complexity of the processing technology. Therefore, the optimization design of the wear resistance of the mating parts between the crankshaft and related components has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, the purpose of the present application is to provide a crankshaft structure for a compressor and a compressor, so as to solve the problem of how to improve the wear resistance of the mating parts of the crankshaft.

[0006] According to the first aspect of the present invention, a crankshaft structure for a compressor is provided, wherein the crankshaft structure for the compressor includes: a core part, the hardness of the core part being H1; an outer peripheral part formed on the outer periphery of the core part, the hardness of the outer peripheral part being H2, and the hardness ratio of the hardness H2 of the outer peripheral part to the hardness H1 of the core part being h, where 1.95 < h < 2.22 or 5.6 ≤ h ≤ 6.2.

[0007] Preferably, when the material of the core part is steel, the outer peripheral part is formed by surface quenching treatment of the core part. In this case, the hardness ratio is 1.95 < h < 2.22; when the material of the core part is chromium, the outer peripheral part is formed by surface carburizing treatment of the core part. In this case, the hardness ratio is 5.6 ≤ h ≤ 6.2.

[0008] Preferably, the thickness of the outer peripheral part is d, where 0.8 mm ≤ d.

[0009] Preferably, the crankshaft structure for a compressor includes: a crankshaft main body, which is sequentially provided with an eccentric portion, a main bearing portion, a main shaft portion, and a lower bearing portion along the axial direction from top to bottom; and bearings, and a plurality of the bearings are respectively installed on the outer circumferences of the eccentric portion, the main bearing portion, and the lower bearing portion.

[0010] Preferably, the crankshaft main body forms the outer peripheral portion at the eccentric portion, the main bearing portion, and the lower bearing portion.

[0011] Preferably, the thickness of the outer peripheral portion formed at the eccentric portion is d1, 0.8 mm ≤ d1 ≤ 2.5 mm, and the ratio of d1 to the radius of the eccentric portion is 3.5% to 16.7%.

[0012] Preferably, the bearing includes: a bushing sleeved on the crankshaft main body; and an inner surface coating provided on the side of the bushing close to the crankshaft main body, and the ratio of the elastic modulus E1 of the inner surface coating to the elastic modulus E2 of the outer peripheral portion is E, 0.24% < E < 0.26%.

[0013] Preferably, the thickness D of the inner surface coating satisfies: 0.12 mm ≤ D ≤ 0.4 mm.

[0014] Preferably, the thickness of the inner surface coating is D1, 0.2 mm ≤ D1 ≤ 0.23 mm.

[0015] According to a second aspect of the present invention, a compressor is provided, wherein the compressor includes the crankshaft structure for a compressor as described above.

[0016] The crankshaft structure for a compressor and the compressor according to the embodiments of the present invention include a core portion and an outer peripheral portion formed on the outer circumference of the core portion. Among them, the hardness of the core portion is H1, and the hardness of the outer peripheral portion is H2. The hardness ratio of the hardness H2 of the outer peripheral portion to the hardness H1 of the core portion is h, 1.95 < h < 2.22 or 5.6 ≤ h ≤ 6.2. Thus, by providing an outer peripheral portion with a higher hardness on the outer circumference of the core portion, the wear resistance of the mating portion between the crankshaft main body and the bearing can be significantly improved, and further the wear caused to the crankshaft main body during the operation of the compressor can be effectively reduced. Thereby, the problem of how to improve the wear resistance of the mating portion of the crankshaft can be effectively solved.

[0017] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the crankshaft structure for a compressor according to the present invention.

[0020] Figure 2 It is according to the present invention Figure 1 The A-A cross-sectional view of

[0021] Figure 3 It is a schematic diagram of the crankshaft structure for a compressor according to the present invention and a part of the structure of the compressor.

[0022] Figure 4 It is a schematic diagram of the crankshaft structure for a compressor according to the present invention and another part of the structure of the compressor.

[0023] Reference numerals: 1 - crankshaft main body; 11 - eccentric part; 12 - main bearing part; 13 - main shaft part; 14 - lower bearing part; 2 - bearing; 3 - oil hole; 100 - core part; 200 - outer peripheral part. Detailed embodiments

[0024] The following detailed embodiments are provided to help readers obtain a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example and is not limited to the order set forth herein. Rather, changes that will be apparent after understanding the disclosure of the present application can be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

[0025] The features described herein can be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0026] Throughout the specification, when an element such as a layer, region, or substrate is described as being "on" another element, "connected to" another element, "coupled to" another element, "above" another element, or "covering" another element, it can be directly "on" the other element, "connected to" the other element, "coupled to" the other element, "above" the other element, or "covering" the other element, or there can be one or more other elements intervening therebetween. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly coupled to" another element, "directly above" another element, or "directly covering" another element, there can be no other elements intervening therebetween.

[0027] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0028] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or parts, these components, elements, regions, layers, or parts are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or part from another. Thus, the first component, element, region, layer, or part as referred to in the examples described herein may also be referred to as the second component, element, region, layer, or part without departing from the teachings of the examples.

[0029] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the figures. Such spatial relationship terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations of "above" and "below" depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relationship terms used herein will be interpreted accordingly.

[0030] The terms used herein are for the purpose of describing various examples only and are not intended to limit the examples. Unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. The terms "comprising", "including" and "having" enumerate the stated features, quantities, operations, components, elements and / or combinations thereof that exist, but do not preclude the existence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof.

[0031] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings, but include changes in shape that occur during manufacturing.

[0032] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible, as will be apparent after understanding the disclosure of the present application.

[0033] As Figures 1 to 4 shown, according to a first aspect of the present invention, a crankshaft structure for a compressor is provided, and the crankshaft structure for the compressor includes a core portion 100 and an outer peripheral portion 200.

[0034] In the following description, reference will be made to Figures 1 to 4 specifically describe the specific structures of the above components of the crankshaft structure for the compressor and the connection relationships of the above components.

[0035] As Figures 1 to 4 shown, in the embodiment, the outer peripheral portion 200 can be formed on the outer periphery of the core portion 100 so that other parts in the compressor cooperate with the outer peripheral portion 200 to prevent the core portion 100 from being directly worn. The hardness of the core portion 100 can be H1, and the hardness of the outer peripheral portion 200 can be H2. The hardness ratio of the hardness H2 of the outer peripheral portion 200 to the hardness H1 of the core portion 100 can be h, where 1.95 < h < 2.22 or 5.6 ≤ h ≤ 6.2. Thus, by providing the outer peripheral portion 200 with a higher hardness on the outer periphery of the core portion 100, the wear resistance of the crankshaft structure for the compressor can be significantly improved, and further the service life of the compressor can be improved.

[0036] Further, preferably, as Figures 1 to 4As shown, in the embodiment, according to the different materials of the core part 100, the hardness ratio h can correspond to different value ranges. Specifically, when the material of the core part 100 is steel (such as 45 steel, etc.), the outer peripheral part 200 is formed by surface quenching treatment of the core part 100. In this case, the hardness ratio h is 1.95 < h < 2.22. The hardness of the outer periphery of the core part 100 can change from 28 HRC (i.e., corresponding to H1) to 55 HRC to 62 HRC (i.e., corresponding to H2). When the material of the core part 100 is chromium (such as 20Cr), the outer peripheral part 200 is formed by surface carburizing treatment of the core part 100. In this case, the hardness ratio h is 5.6 ≤ h ≤ 6.2. The hardness of the outer periphery of the core part 100 can change from 10 HRC (i.e., corresponding to H1) to 56 HRC to 62 HRC (i.e., corresponding to H2).

[0037] In the embodiment, when the material of the core part 100 is steel and h ≥ 2.22, or when the material of the core part 100 is chromium and h > 6.2, the outer peripheral part 200 will cause the propagation of microcracks due to excessive hardness, resulting in cracking or spalling of the outer peripheral part 200. When the material of the core part 100 is steel and h ≤ 1.95, or when the material of the core part 100 is chromium and h < 5.6, the outer peripheral part 200 will be difficult to effectively reduce wear due to insufficient hardness, affecting the service life of the compressor. Therefore, when the hardness ratio h adopts the value ranges of 1.95 < h < 2.22 and 5.6 ≤ h ≤ 6.2, the outer peripheral part 200 can better play the function of reducing wear.

[0038] Preferably, as Figures 1 to 4 shown, in the embodiment, the crankshaft structure for the compressor can include a crankshaft main body 1 and bearings 2. Among them, the crankshaft main body 1 can be sequentially provided with an eccentric part 11, a main bearing part 12, a main shaft part 13, and a lower bearing part 14 along the axial direction from top to bottom. The number of the bearings 2 can be multiple, and the multiple bearings 2 can be respectively installed on the outer peripheries of the eccentric part 11, the main bearing part 12, and the lower bearing part 14. The types of the multiple bearings 2 can be different. Among them, the bearing 2 installed on the outer periphery of the eccentric part 11 can be a sliding bearing, and the sliding bearing can form a stable oil film at high speeds to provide a good lubrication effect, reducing friction and wear.

[0039] Preferably, as Figure 1 and Figure 2As shown, in the embodiment, the eccentric part 11, the main bearing part 12, the main shaft part 13, and the lower bearing part 14 can all be formed into a cylindrical structure. Thus, when the outer peripheral part 200 is formed on the eccentric part 11, the main bearing part 12, the main shaft part 13, or the lower bearing part 14, the outer peripheral part 200 can be formed only on its circumferential surface. With such a setting, the outer peripheral part 200 is coated on the outer side in the radial direction of the core part 100, and the oil hole 3 can be formed in the core part 100. It is worth mentioning that Figure 2 The content in it is only for illustration. In the actual processing process, due to process reasons, the boundary line between the outer peripheral part 200 and the core part 100 will be non-uniformly linear, and the outer peripheral part 200 will extend radially (microscopically) from the outside to the inside of the core part 100 in a radial shape.

[0040] More preferably, as Figure 3 and Figure 4 shown, in the embodiment, to reduce the process time and lower the processing cost, the outer peripheral part 200 can be provided only at the eccentric part 11, the main bearing part 12, and the lower bearing part 14 of the crankshaft body 1. That is, in the actual production process, surface hardening treatment or surface carburizing treatment can be carried out only at the parts of the crankshaft body 1 for installing the bearing 2, so as to avoid wasting time and cost.

[0041] Preferably, as Figure 1 and Figure 2 shown, in the embodiment, the thickness of the outer peripheral part 200 is d, and 0.8mm ≤ d. With such a setting, it can be ensured that the outer peripheral part 200 can effectively reduce wear during the operation of the compressor.

[0042] Furthermore, preferably, as Figures 1 to 3 shown, in the embodiment, the thickness of the outer peripheral part 200 formed at the eccentric part 11 can be d1, and 0.8mm ≤ d1 ≤ 2.5mm. Specifically, in a scroll compressor, since a centrifugal force is generated when the moving disk makes an eccentric rotary translation around the center of the stationary disk, and the centrifugal force will cause an increase in the contact pressure between the moving disk and the eccentric part 11, thereby exacerbating the wear of the eccentric part 11. At the same time, the centrifugal force will also cause the uneven distribution of the lubricating oil film, further exacerbating the wear of the eccentric part 11. Therefore, it is necessary to carry out surface hardening treatment or surface carburizing treatment on the eccentric part 11 for a longer time, so that the thickness of the outer peripheral part 200 at the eccentric part 11 can be greater than the thickness of the outer peripheral part 200 of other parts of the crankshaft body 1, in order to extend the overall service life of the crankshaft body 1.

[0043] However, when the thickness d1 of the outer peripheral portion 200 is greater than 2.5 mm, the eccentric portion 11 is subjected to surface hardening treatment or surface carburizing treatment for too long. In this way, not only time and material costs are consumed, but also the hardness of the outermost part of the outer peripheral portion 200 is too high, which in turn causes cracks on the surface of the eccentric portion 11, affecting the performance of the crankshaft main body 1.

[0044] Preferably, as Figures 1 to 3 shown, in the embodiment, the diameter of the eccentric portion 11 may be 30 mm to 45 mm (it may be 30 mm, 35 mm, 38 mm or 45 mm), and the ratio of the thickness d1 of the outer peripheral portion 200 to the radius of the eccentric portion 11 may be 3.5% to 16.7%. With such a setting, the surface hardness of the eccentric portion 11 can not only meet the requirement of reducing wear, but also will not be too high to cause cracks.

[0045] In addition, preferably, as Figures 1 to 4 shown, in the embodiment, the bearing 2 may include a bushing and an inner surface coating. The bushing may be sleeved on the crankshaft main body 1. The inner surface coating may be provided on the side of the bushing close to the crankshaft main body 1, so that the inner surface coating is in contact with the crankshaft main body 1. Preferably, the ratio of the elastic modulus E1 of the inner surface coating to the elastic modulus E2 of the outer peripheral portion 200 is E, and 0.24% < E < 0.26%.

[0046] With such a setting, the service life of the bearing 2 can be improved, and the stability of the crankshaft main body 1 can be improved. Specifically, the lower elastic modulus enables the bearing 2 to have a certain elastic deformation ability when bearing a load, so as to disperse stress and extend the service life. At the same time, the lower elastic modulus can improve the wear resistance of the bearing 2. The crankshaft main body 1 needs to bear a large centrifugal force, torque and other stresses, so a higher elastic modulus is required to ensure its stability under various working conditions. Therefore, when the ratio E of the elastic modulus is kept at 0.24% < E < 0.26%, the stability of the crankshaft main body 1 can be ensured, and the wear resistance of the bearing 2 can be improved.

[0047] Preferably, in the embodiment, the bushing may be a metal bushing (such as steel material or other metals with stronger rigidity), and the inner surface coating may be a mixed coating of polytetrafluoroethylene material (i.e., PTFE material) and metal (the metal part may be copper or aluminum in a porous state formed after high-temperature sintering, so that PTFE can be rolled into the micropores). The polytetrafluoroethylene material has the characteristic of low friction, and can optimize the material strength and stability. Cooperating with the hardened crankshaft main body 1 can further reduce the wear of the crankshaft main body 1. In addition, the metal material part in the inner surface coating can further reduce friction, and it realizes reducing the force transmitted to the bushing by absorbing the frictional force and centrifugal force.

[0048] More preferably, in the embodiment, the thickness D of the inner surface coating may satisfy: 0.12 mm ≤ D ≤ 0.4 mm. Further preferably, the thickness of the inner surface coating may be D1, where 0.2 mm ≤ D1 ≤ 0.23 mm. With such a setting, when the thickness D1 of the inner surface coating ≥ 0.2 mm, it can ensure that the alloy material is not exposed on the surface and wears against the crankshaft main body 1. When the thickness D1 of the inner surface coating ≤ 0.23 mm, it can ensure the radial installation dimension to prevent the problem of impossible installation caused by the over-thick inner surface coating.

[0049] The specific embodiments are verified as follows:

[0050] Life test conditions: suction pressure 0.17 Mpa(G), exhaust pressure 3.83 Mpa(G), running for 500 h.

[0051] Roughness test standard and method: The test method and standard of GB / T 3505 - 2000 are adopted.

[0052] Comparative example 1: When the material of the crankshaft main body 1 is 45 steel, no surface quenching treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0053] Comparative example 2: When the material of the crankshaft main body 1 is 20Cr, no surface carburizing treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0054] Example 1: When the material of the crankshaft main body 1 is 45 steel, surface quenching treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0055] Example 2: When the material of the crankshaft main body 1 is 45 steel, surface quenching treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0056] Example 3: When the material of the crankshaft main body 1 is 45 steel, surface quenching treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0057] Example 4: When the material of the crankshaft main body 1 is 20Cr, surface carburizing treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0058] Example 5: When the material of the crankshaft main body 1 is 20Cr, surface carburizing treatment is carried out. After finish machining, the roughness of each position is tested and then the life test is carried out.

[0059]

[0060] It can be concluded that when the hardness ratio h takes values in the range of 1.95 < h < 2.22 and 5.6 ≤ h ≤ 6.2, the outer peripheral portion 200 can effectively perform the function of reducing wear.

[0061] In addition, as Figures 3 to 4 shown, according to a second aspect of the present invention, there is provided a compressor, which includes the crankshaft structure for a compressor as described above.

[0062] During use, the crankshaft structure for a compressor significantly improves the wear resistance of the crankshaft main body 1 by providing an outer peripheral portion 200 with a higher hardness on the outer periphery of the core portion 100, and thus effectively reduces the wear suffered by the crankshaft main body 1 during the operation of the compressor, thereby improving the service life of the compressor.

[0063] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily conceive of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

1. A crankshaft structure for a compressor, disposed in the compressor, characterized in that, The crankshaft structure for a compressor includes: A core part, the hardness of the core part being H1; An outer peripheral part formed on the outer periphery of the core part, the hardness of the outer peripheral part being H2, and the hardness ratio of the hardness H2 of the outer peripheral part to the hardness H1 of the core part being h, where 1.95 < h < 2.22 or 5.6 ≤ h ≤ 6.

2.

2. The crankshaft structure for a compressor according to claim 1, characterized in that, When the material of the core part is steel, the outer peripheral part is formed by surface quenching treatment of the core part. In this case, the hardness ratio is 1.95 < h < 2.22; When the material of the core part is chromium, the outer peripheral part is formed by surface carburizing treatment of the core part. In this case, the hardness ratio is 5.6 ≤ h ≤ 6.

2.

3. The crankshaft structure for a compressor according to claim 2, characterized in that, The thickness of the outer peripheral part is d, where 0.8 mm ≤ d.

4. The crankshaft structure for a compressor according to claim 2, characterized in that, The crankshaft structure for a compressor includes: A crankshaft main body, which is sequentially provided with an eccentric part, a main bearing part, a main shaft part, and a lower bearing part along the axial direction from top to bottom; and Bearings, with multiple bearings respectively installed on the outer peripheries of the eccentric part, the main bearing part, and the lower bearing part.

5. The crankshaft structure for a compressor according to claim 4, characterized in that, The crankshaft main body forms the outer peripheral part at the eccentric part, the main bearing part, and the lower bearing part.

6. The crankshaft structure for a compressor according to claim 4, characterized in that, The thickness of the outer peripheral part formed at the eccentric part is d1, where 0.8 mm ≤ d1 ≤ 2.5 mm, and the ratio of d1 to the radius of the eccentric part is 3.5% to 16.7%.

7. The crankshaft structure for a compressor according to any one of claims 4 to 6, characterized in that, The bearings include: A bushing sleeved on the crankshaft main body; and An inner surface coating provided on the side of the bushing close to the crankshaft main body, and the ratio of the elastic modulus E1 of the inner surface coating to the elastic modulus E2 of the outer peripheral part is E, where 0.24% < E < 0.26%.

8. The crankshaft structure for a compressor according to claim 7, characterized in that, The thickness D of the inner surface coating satisfies: 0.12 mm ≤ D ≤ 0.4 mm.

9. The crankshaft structure for a compressor according to claim 7, characterized in that, The thickness of the inner surface coating is D1, where 0.2 mm ≤ D1 ≤ 0.23 mm.

10. A compressor, characterized in that, The compressor includes the crankshaft structure for a compressor according to any one of claims 1 to 9.

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