Roller and compressor

Abstract

The present invention relates to a roller and a compressor, which are used to be sleeved in the cylinder of the compressor, and include: an outer roller, which is annular and has at least one mounting groove on its inner circumferential surface; at least one inner roller, which is sleeved in the at least one mounting groove respectively; wherein the linear expansion coefficient of one of the outer roller and any inner roller is greater than the linear expansion coefficient of the cylinder, and the linear expansion coefficient of the other is less than the linear expansion coefficient of the cylinder, and the inner roller and the outer roller can be combined to form a roller with a linear expansion coefficient close to that of the cylinder, so that when the compressor is working, the consistency of the thermal expansion amount of the roller and the cylinder along the axial direction of the roller is better, so that the assembly gap between the roller and the axial flange of the cylinder is kept stable, and the assembly gap between the roller and the flange after thermal expansion is prevented from becoming too large or too small, and the refrigerant in the cylinder is prevented from leaking or the roller is stuck, thereby improving the reliability of the compressor.

Description

Technical Field

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

[0002] The compressor is a driven fluid machine that can lift low-pressure gas into high-pressure gas. It is the heart of the refrigeration system. It sucks low-temperature and low-pressure refrigerant gas from the suction pipe, compresses it by driving the crankshaft and rollers through the motor, and discharges high-temperature and high-pressure refrigerant gas to the exhaust pipe to provide power for the heat exchange cycle. In addition, centrifugal force will be generated during the rotation of the crankshaft and rollers. Generally, a matching balance block is set on the motor rotor to offset the centrifugal force. However, if the centrifugal force is too large, the large mass of the balance block will exert a greater force on the crankshaft, increase the disturbance of the crankshaft, and then the crankshaft will produce greater vibration and noise, and the crankshaft is prone to wear.

[0003] Therefore, in order to reduce vibration and noise, and reduce crankshaft wear, lightweighting of rollers is one of the current development trends. This is mainly because the mass of the roller is small, and the centrifugal force generated when the roller rotates eccentrically is low, which can reduce the mass of the balance block and the deflection of the crankshaft, which can reduce vibration and noise. At the same time, the reduction of crankshaft deflection can also reduce crankshaft wear. In addition, rollers with smaller mass are also conducive to high-speed operation of the compressor.

[0004] Generally, the roller sleeve is installed in the cylinder, and flanges are set at both ends of the roller axis. If lightweight rollers are used, the installation gap between the roller and the flange cannot be effectively guaranteed after the compressor enters the working state. The gap between the roller and the flange is easy to be too large or too small, which can easily cause the refrigerant to leak from the gap between the roller and the flange or the roller and the flange to get stuck, resulting in poor compressor reliability. Summary of the invention

[0005] Based on this, it is necessary to provide a roller and a compressor to address the problem of poor compressor reliability when lightweight rollers are used.

[0006] A roller is used to be sleeved in a cylinder of a compressor, and comprises:

[0007] An outer roller, the outer roller is annular, and at least one mounting groove is formed on the inner circumference of the outer roller;

[0008] at least one inner roller, wherein the at least one inner roller is respectively sleeved in the at least one mounting groove;

[0009] Wherein, the linear expansion coefficient of one of the outer roller and any one of the inner rollers is greater than the linear expansion coefficient of the cylinder, and the linear expansion coefficient of the other one is smaller than the linear expansion coefficient of the cylinder.

[0010] In the above-mentioned rollers, the inner roller and the outer roller are nested and assembled together, and compared with the linear expansion coefficient of the cylinder, the linear expansion coefficient of one of the inner roller and the outer roller is larger, and the linear expansion coefficient of the other is smaller. After the inner roller and the outer roller are combined, a roller with a linear expansion coefficient close to that of the cylinder can be matched, so that when the compressor is working, the consistency of the thermal expansion amount of the roller and the cylinder along the axial direction of the roller is better, so that the assembly gap between the roller and the axial flange of the cylinder remains stable, preventing the assembly gap between the roller and the flange from becoming too large or too small after thermal expansion, preventing refrigerant leakage in the cylinder or roller jamming, and improving the reliability of the compressor.

[0011] In some of these embodiments, an average density of the outer roller and all of the inner rollers is less than a density of the cylinder.

[0012] In some embodiments, the outer roller includes an outer ring and an inner ring arranged on the inner circumference of the outer ring, the height of the inner ring along the axial direction of the roller is smaller than the height of the outer ring, and the mounting groove is defined between the inner ring and the outer ring.

[0013] In some embodiments, the mounting grooves are formed on one or both axial sides of the inner ring, and the number of the inner rollers matches the number of the mounting grooves.

[0014] In some embodiments, in a natural state, along the axial direction of the roller, there is an assembly gap between the roller and the flange at the axial end of the cylinder;

[0015] Based on the fact that the sum of the linear expansion of the inner ring and the inner roller is consistent with the linear expansion of the cylinder, and the sum of the inner ring height, the height of all the inner rollers and the assembly clearance is equal to the cylinder height, the height of the inner ring and all the inner rollers along the axial direction of the roller in the natural state is determined.

[0016] In some embodiments, the final temperatures of the roller and the cylinder are the same during operation of the compressor, the material of all the inner rollers is the same, the linear expansion coefficient of the cylinder is α, the linear expansion coefficient of the outer roller is α1, and the linear expansion coefficient of the inner roller is α2;

[0017] Along the axial direction of the roller, the height of the inner ring is H1, the height of all the inner rollers on the outer roller is H2, the height of the cylinder is H, the assembly clearance is c, H1=(Hα- Hα2+cα2) / (α1-α2), H2=(Hα- Hα1+cα1) / (α2-α1).

[0018] In some embodiments, the ratio of the thermal diffusivity of the outer roller to the thermal diffusivity of the cylinder is 0.8-1.2, and the ratio of the thermal diffusivity of the inner roller to the thermal diffusivity of the cylinder is 0.8-1.2.

[0019] In some embodiments, mounting grooves are formed on opposite sides of the inner ring in the axial direction, the number of the inner rollers is two, the two inner rollers are respectively arranged in the two mounting grooves, the two inner rollers are made of different materials, and the material of one of the two inner rollers is wear-resistant material.

[0020] In some embodiments, along the axial direction of the roller, the inner roller includes at least two stacked sub-inner rollers, at least two of the sub-inner rollers are stacked in the same mounting groove, and at least two of the sub-inner rollers are made of different materials, and the material of the one farthest from the inner ring among the at least two sub-inner rollers in the same mounting groove is wear-resistant material.

[0021] In some embodiments, the cylinder is made of cast iron, the outer roller is made of alumina ceramic, and at least one inner roller is made of aluminum alloy.

[0022] In some embodiments, the cylinder is made of cast iron, the linear expansion coefficient of the outer roller is greater than the linear expansion coefficient of the cylinder, and the linear expansion coefficient of at least one of the inner rollers is less than the linear expansion coefficient of the cylinder;

[0023] In a natural state, along the axial direction of the roller, the inner roller having a linear expansion coefficient smaller than the linear expansion coefficient of the cylinder is arranged to protrude from the outer roller.

[0024] In some embodiments, the cylinder is made of cast iron, the outer roller is made of gray cast iron, and the inner roller is made of alumina ceramic.

[0025] A compressor comprises a cylinder, a flange and the above-mentioned roller, wherein the roller is eccentrically arranged in the cylinder and the flange is arranged at the end of the cylinder; when the compressor is working, the assembly clearance between the roller and the flange along the axial direction of the roller is within a preset range. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic diagram of the structure of a compressor in some embodiments of the present application;

[0027] FIG2 is a schematic diagram of the structure of a roller in some embodiments of the present application;

[0028] FIG3 is a schematic diagram of the structure of an outer roller in some embodiments of the present application;

[0029] FIG4 is a schematic diagram of the structure of a roller in some embodiments of the present application;

[0030] FIG. 5 is a schematic diagram of the structure of rollers in other embodiments of the present application.

[0031] Explanation of the reference numerals: 100, compressor; 10, cylinder; 30, flange; 50, roller; 60, outer roller; 61, mounting groove; 62, outer ring; 64, inner ring; 80, inner roller; 82, sub-inner roller. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0038] As described in the background technology, if the compressor uses lightweight rollers, the compressor reliability is poor. The inventor has found through research that after the compressor enters the working state, the roller and the cylinder will expand due to heat, and the lightweight roller and the cylinder will expand differently after being heated. For example, if one of the roller and the cylinder expands more than the other, the gap between the roller and the flange at the end of the cylinder may increase or decrease. If the gap between the roller and the flange is too large, it is easy to cause refrigerant leakage, and if the gap between the roller and the flange is too small, it is easy to cause the roller to get stuck.

[0039] In order to solve the above technical problems, the inventors have found that the thermal expansion of the roller and the cylinder can be kept close. In this way, when the temperature of the roller and the cylinder rises during the operation of the compressor, the roller and the cylinder expand synchronously in the axial direction, preventing the assembly gap between the roller and the cylinder end flange from becoming larger or smaller, thereby improving the reliability of the compressor operation.

[0040] 1 to 3, according to some embodiments of the present application, the compressor 100 includes a cylinder 10, a flange 30 and a roller 50, wherein the flange 30 is disposed at the axial end of the cylinder 10 to close the accommodation cavity inside the cylinder 10. The roller 50 is eccentrically disposed in the cylinder 10 and eccentrically rotates in the accommodation cavity of the cylinder 10 to compress the refrigerant in the accommodation cavity, thereby discharging the high-temperature and high-pressure refrigerant to the exhaust pipe.

[0041] During the operation of the compressor 100, the assembly clearance between the roller 50 and the flange 30 along the axial direction of the roller 50 is within a preset range. During the operation of the compressor 100, the refrigerant is compressed to form a high-temperature and high-pressure refrigerant. The roller 50 and the cylinder 10 and other components in contact with the refrigerant will expand in the axial direction of the roller 50 due to the increase in temperature. The assembly clearance between the roller 50 and the flange 30 at the end of the cylinder 10 can be within a preset range, preventing the roller 50 and the cylinder 10 from expanding due to heat, causing the assembly clearance between the roller 50 and the flange 30 to exceed the preset range, preventing the roller 50 from getting stuck or the cylinder 10 from leaking refrigerant, and improving the reliability of the operation of the compressor 100.

[0042] The roller 50 includes an outer roller 60 and at least one inner roller 80. The outer roller 60 is annular, and at least one mounting groove 61 is formed on the inner circumference of the outer roller 60. At least one inner roller 80 is respectively sleeved in the at least one mounting groove 61, so that the inner roller 80 is nested inside the outer roller 60. The linear expansion coefficient of one of the outer roller 60 and any one of the inner rollers 80 is greater than the linear expansion coefficient of the cylinder 10, and the linear expansion coefficient of the other is less than the linear expansion coefficient of the cylinder 10.

[0043] In this way, the inner roller 80 and the outer roller 60 are nested and assembled together, and compared with the linear expansion coefficient of the cylinder 10, the linear expansion coefficient of one of the inner roller 80 and the outer roller 60 is larger, and the linear expansion coefficient of the other is smaller. After the inner roller 80 and the outer roller 60 are combined, a roller 50 with a linear expansion coefficient close to that of the cylinder 10 can be matched. Therefore, when the compressor 100 is working, the consistency of the axial thermal expansion of the roller 50 and the cylinder 10 along the roller 50 is better, so that the assembly gap between the roller 50 and the axial flange 30 of the cylinder 10 remains stable, preventing the assembly gap between the roller 50 and the flange 30 from becoming too large or too small after thermal expansion, preventing the refrigerant in the cylinder 10 from leaking or the roller 50 from getting stuck, and improving the reliability of the compressor 100.

[0044] The average density of the outer roller 60 and all the inner rollers 80 is less than the density of the cylinder 10, so the roller 50 formed by assembling the outer roller 60 and the inner roller 80 has a low density and a light weight, which meets the design requirements of the lightweight roller 50, and the roller 50 can rotate at high speed. In this way, the roller 50 is set as a combination of the inner roller 80 and the outer roller 60, which can meet the design requirements of the lightweight roller 50, and can also make the expansion of the roller 50 close to the expansion of the cylinder 10 by selecting the inner roller 80 and the outer roller 60 with different linear expansion coefficients, thereby improving the stability of the assembly gap between the roller 50 and the flange 30, improving the reliability of the operation of the compressor 100, and improving the feasibility of the compressor 100 using the lightweight roller 50.

[0045] The outer roller 60 includes an outer ring 62 and an inner ring 64 disposed on the inner circumference of the outer ring 62. The height of the inner ring 64 along the axial direction of the roller 50 is less than the height of the outer ring 62. A mounting groove 61 is defined between the inner ring 64 and the outer ring 62. In this way, the outer roller 60 includes the outer ring 62 and the inner ring 64. The inner ring 64 is relatively low in height. A mounting groove 61 is defined between the inner ring 64 and the outer ring 62. The mounting groove 61 does not extend onto the outer ring 62, does not damage the integrity of the outer circumference of the roller 50, and prevents the outer surface of the roller 50 from being delaminated and causing refrigerant leakage.

[0046] According to some embodiments of the present application, a mounting groove 61 is formed on one or both sides of the inner ring 64 in the axial direction, and the number of the inner rollers 80 matches the number of the mounting grooves 61. For example, one side of the inner ring 64 in the axial direction is flush with the outer ring 62, and the other side of the inner ring 64 in the axial direction is recessed relative to the outer ring 62. The mounting groove 61 is formed on one side of the inner ring 64 in the axial direction, which is equivalent to forming the mounting groove 61 at one end of the outer roller 60 in the axial direction, and the inner roller 80 is correspondingly provided with one. In the material selection process, the linear expansion coefficient of one of the inner roller 80 and the outer roller 60 is set to be greater than the linear expansion coefficient of the cylinder 10, and the linear expansion coefficient of the other of the inner roller 80 and the outer roller 60 is selected to be less than the linear expansion coefficient of the cylinder 10. In this way, the linear expansion coefficient of the roller 50 formed by the combination of the inner roller 80 and the outer roller 60 is close to the linear expansion coefficient of the cylinder 10, which prevents the installation gap between the roller 50 and the flange 30 from becoming too large or too small, thereby improving the reliability of the operation of the compressor 100.

[0047] For another example, both sides of the inner ring 64 in the axial direction are recessed relative to the outer ring 62, and both sides of the inner ring 64 in the axial direction are formed with mounting grooves 61, and the number of rollers 50 is correspondingly set to two. Equivalently, mounting grooves 61 are formed at both ends of the outer roller 60 in the axial direction, and two rollers 50 are correspondingly set. In the material selection process, one of the two inner rollers 80 is selected, and the linear expansion coefficient of one of the inner roller 80 and the outer roller 60 is greater than the linear expansion coefficient of the cylinder 10, and the linear expansion coefficient of the other is less than the linear expansion coefficient of the cylinder 10, so that the linear expansion coefficient of the roller 50 after the combination is close to the linear expansion coefficient of the cylinder 10. In addition, the remaining inner roller 80 of the two inner rollers 80 can be selected to have a linear expansion coefficient greater than the linear expansion coefficient of the cylinder 10, or less than the linear expansion coefficient of the cylinder 10, or equal to the linear expansion coefficient of the cylinder 10. There is no limitation on how to select the linear expansion coefficient of the remaining inner roller 80, and it can be selected according to actual conditions.

[0048] The following describes an example of selecting materials for the inner roller 80 and the outer roller 60 according to the above rule, taking the case where the cylinder 10 is made of cast iron.

[0049] According to some embodiments of the present application, the material of the outer roller 60 is alumina ceramic, and the linear expansion coefficient of alumina ceramic is smaller than that of cast iron, so that the linear expansion coefficient of the outer roller 60 is smaller than that of the cylinder 10. At the same time, the material of at least one inner roller 80 is aluminum alloy, and the linear expansion coefficient of aluminum alloy is greater than that of cast iron, so that the linear expansion coefficient of at least one inner roller 80 is greater than that of the cylinder 10, so that the combination of the inner roller 80 and the outer roller 60 can be matched to form a roller 50 with a thermal expansion amount close to that of the cylinder 10. In addition, the roller 50 formed by the combination of alumina ceramic and aluminum alloy is lighter in weight, the centrifugal force during the eccentric rotation of the roller 50 is smaller, the corresponding balancing block set on the motor rotor is smaller in weight, the disturbance generated by the crankshaft under the action of the balancing block is smaller, and the crankshaft can reliably drive the lightweight roller 50 to rotate at high speed.

[0050] Optionally, the inner roller 80 is made of 4032 aluminum alloy or 7075 aluminum alloy.

[0051] According to other embodiments of the present application, the cylinder 10 is made of cast iron, the linear expansion coefficient of the outer roller 60 is greater than the linear expansion coefficient of the cylinder 10 , and the linear expansion coefficient of at least one inner roller 80 is less than the linear expansion coefficient of the cylinder 10 .

[0052] If the linear expansion coefficient of the outer roller 60 is greater than that of the cylinder 10, and the linear expansion coefficient of the inner roller 80 is less than that of the cylinder 10, the expansion of the outer roller 60 is greater than that of the inner roller 80 after the compressor 100 generates heat. If the axial end face of the inner roller 80 is flush with the axial end face of the outer roller 60 in the initial natural state, the outer roller 60 will protrude from the inner roller 80 after expansion, and a height difference will be generated between the outer roller 60 and the inner roller 80, thereby making the axial end face of the roller 50 uneven, and the refrigerant in the cylinder 10 will easily leak from the end face of the roller 50.

[0053] In order to prevent this situation, in the natural state, the inner roller 80, whose linear expansion coefficient is smaller than that of the cylinder 10, is arranged to protrude from the outer roller 60 along the axial direction of the roller 50. The natural state refers to the state when the compressor 100 is assembled under normal temperature, and the expansion state of each component after heating during the operation of the compressor 100 is the opposite state of the natural state. In this way, in the initial design stage, the height of the outer roller 60 is set lower than the height of the inner roller 80, and the inner roller 80 is arranged to protrude from the outer roller 60. After subsequent heating, the outer roller 60 expands more and the inner roller 80 expands less. Finally, the axial end faces of the two can be basically flush to form the axial end face of the roller 50, so as to prevent the refrigerant in the cylinder 10 from leaking from the axial end face of the roller 50.

[0054] Optionally, the material of the cylinder 10 is cast iron, and the material of the outer roller 60 is gray cast iron, the linear expansion coefficient of gray cast iron is slightly greater than that of cast iron, and the thermal conductivity of the two is close. At the same time, the material of the inner roller 80 is alumina ceramic, and the linear expansion coefficient of alumina ceramic is less than that of cast iron. In this way, the linear expansion coefficient of the roller 50 produced by combining gray cast iron and alumina ceramic is close to the linear expansion coefficient of the cylinder 10 made of cast iron.

[0055] According to some embodiments of the present application, in a natural state, along the axial direction of the roller 50, there is an assembly gap between the roller 50 and the flange 30 at the axial end of the cylinder 10, that is, a suitable assembly gap is reserved between the roller 50 and the flange 30 during assembly, allowing the roller 50 to rotate in the cylinder 10 while preventing refrigerant leakage in the cylinder 10.

[0056] Furthermore, the height of the inner ring 64 and all the inner rollers 80 along the axial direction of the roller 50 in the natural state is determined based on the fact that the sum of the linear expansion of the inner ring 64 and the inner roller 80 of the outer roller 60 is consistent with the linear expansion of the cylinder 10, and the sum of the height of the inner ring 64, the height of all the inner rollers 80 and the assembly clearance is equal to the height of the cylinder 10. That is to say, after the material of the inner roller 80 and the outer roller 60 is determined, in order to ensure that the thermal expansion of the roller 50 is consistent with that of the cylinder 10, the inner ring 64 of the inner roller 80 and the outer roller 60 also needs to be set to a suitable height.

[0057] Specifically, the sum of the height of the inner ring 64, the height of all rollers 50 and the assembly clearance is equal to the height of the cylinder 10. This condition means that in the natural state, when the roller 50 formed by the inner roller 80 and the outer roller 60 is assembled in the cavity, there is a preset assembly clearance between the roller 50 and the flange 30, the roller 50 will not be stuck, and the preset assembly clearance will not be too large, and the leakage of the refrigerant in the cylinder 10 through the assembly is small, which meets the requirements of the normal operation of the compressor 100. The sum of the linear expansion of the inner ring 64 and the inner roller 80 of the outer roller 60 is consistent with the linear expansion of the cylinder 10. This condition means that when the compressor 100 generates heat and expands, the roller 50 formed by the inner roller 80 and the outer roller 60 is consistent with the expansion of the cylinder 10, so that the assembly clearance between the roller 50 and the flange 30 at the axial end of the cylinder 10 is basically consistent with the natural state, and the assembly clearance will not change too large or too small.

[0058] Therefore, the heights of the inner roller 80 and the inner ring 64 of the outer roller 60 can be determined by the above two constraints. Conversely, after the heights of the inner roller 80 and the outer roller 60 are determined by the above constraints, the assembly gap between the roller 50 and the flange 30 will not change too much during the operation of the compressor 100, thereby meeting the design requirements of lightweight and high-speed rotation of the roller 50.

[0059] The final temperatures of the roller 50 and the cylinder 10 are the same during the operation of the compressor 100, that is, the temperature when the temperature of the roller 50 and the cylinder 10 rises to a stable temperature after the compressor 100 has been operated for a period of time is the final temperature. Because the refrigerant in the compressor 100 is in contact with the cylinder 10 and the roller 50, the final temperatures of the roller 50 and the cylinder 10 tend to be the same through heat conduction of the refrigerant. In this way,

[0060] Specifically in one embodiment, the material of all the inner rollers 80 is consistent, the linear expansion coefficient of the cylinder 10 is α, the linear expansion coefficient of the outer roller 60 is α1, and the linear expansion coefficient of the inner roller 80 is α2; along the axial direction of the roller 50, the height of the inner ring 64 is H1, the height of all the inner rollers 80 on the outer roller 60 is H2, the height of the cylinder 10 is H, the assembly clearance is c, H1=(Hα- Hα1+cα2) / (α1-α2), H2=(Hα- Hα1+cα2) / (α2-α1).

[0061] In the initial natural state, along the axial direction of the roller 50, the height of the cylinder 10 is equal to the sum of the height of the inner ring 64 of the outer roller 60, the height of all the inner rollers 80 and the assembly clearance, that is, H=H1+H2+c. After the compressor 100 has worked for a period of time and the temperature has risen and stabilized, the final temperatures of the cylinder 10, the outer roller 60 and the inner roller 80 are T, T1, and T2 respectively. The thermal expansion of the cylinder 10 is HαT, the thermal expansion of the inner ring 64 of the outer roller 60 is Hα1 T1, and the thermal expansion of the inner roller 80 is Hα2 T2. The thermal expansion of the cylinder 10 is equal to the sum of the thermal expansion of the inner ring 64 of the outer roller 60 and the thermal expansion of the inner roller 80, that is, HαT= Hα1T1+Hα2T2. Since the temperature is variable, the final temperature of the cylinder 10, the outer roller 60 and the inner roller 80 will be different under different working conditions. For the convenience of calculation, let T=T1=T2, and then Hα=Hα1+Hα2 can be obtained. According to the two functions H= H1+ H2+c and Hα= Hα1+ Hα2, it can be determined that H1=(Hα- Hα2+cα2) / (α1-α2) and H2=(Hα- Hα1+cα1) / (α2-α1). By setting the heights of the inner roller 80 and the inner ring 64 of the outer roller 60 in this way, the consistency of the thermal expansion amounts of the roller 50 and the cylinder 10 can be improved, thereby improving the reliability of the compressor 100.

[0062] In addition, when there are two inner rollers 80 and they are made of different materials, the functional relationship is also limited according to the height relationship between the initial state and the final temperature state, and after the height of one of the two inner rollers 80 is determined in advance, the height of the remaining inner roller 80 and the inner ring 64 of the outer roller 60 can be determined by the above two limiting functions, which will not be shown and introduced here.

[0063] According to some embodiments of the present application, the ratio of the thermal diffusivity of the outer roller 60 to the thermal diffusivity of the cylinder 10 is 0.8-1.2, and the ratio of the thermal diffusivity of the inner roller 80 to the thermal diffusivity of the cylinder 10 is 0.8-1.2. In this way, the thermal diffusivities of the inner roller 80 and the outer roller 60 are close to the thermal diffusivity of the cylinder 10, and the thermal diffusivity of the roller 50 is close to that of the cylinder 10, thereby preventing the roller 50 from getting stuck during the heating or cooling process.

[0064] If the thermal diffusivity of the roller 50 is large and the thermal diffusivity of the cylinder 10 is small, the roller 50 heats up faster before reaching the final temperature, and then the roller 50 expands faster, and the roller 50 is easy to get stuck. In addition, if the thermal diffusivity of the roller 50 is small and the thermal diffusivity of the cylinder 10 is large, during the cooling process after the end of work, the roller 50 cools down slowly and the cylinder 10 cools down quickly, the expansion of the roller 50 is large, and the roller 50 is also easy to get stuck. If the compressor 100 is restarted at this time, wear will occur. Because, in order to prevent the roller 50 and the cylinder 10 from getting stuck due to the misalignment of the temperature change rhythm, the thermal diffusivities of the roller 50 and the cylinder 10 are set to be close.

[0065] Specifically, the thermal diffusivity , is the heat transfer coefficient, C is the specific heat capacity, ρ is the density, and the thermal diffusivities of the inner roller 80, the outer roller 60 and the cylinder 10 are kept within the same preset range and are arranged close to each other.

[0066] Referring to FIG. 4 , according to some embodiments of the present application, mounting grooves 61 are formed at opposite ends of the inner ring 64 in the axial direction, and there are two inner rollers 80, which are respectively arranged in the two mounting grooves 61. The materials of the two inner rollers 80 are different, and the material of one of the two inner rollers 80 is wear-resistant material. In this way, inner rollers 80 are arranged at both ends of the outer roller 60 in the axial direction, and one of the inner rollers 80 is mainly used to match with the outer roller 60 to make the linear expansion coefficient of the roller 50 close to the linear expansion coefficient of the cylinder 10, and the other inner roller 80 can be made of wear-resistant material to improve the wear resistance of the roller 50 on the side of the inner roller 80, thereby improving the service life of the roller 50.

[0067] Specifically, during the installation of the roller 50 , the inner roller 80 formed of the wear-resistant material may be installed toward the side that is easily worn, so as to give full play to the role of the wear-resistant inner roller 80 .

[0068] It is understandable that in some other embodiments, the two inner rollers 80 may not be made of wear-resistant materials, and the two inner rollers 80 may also be made of other materials. Inner rollers 80 of various materials can be selected to combine the roller 50, so as to combine the roller 50 whose linear expansion coefficient is closer to the linear expansion coefficient of the cylinder 10.

[0069] 5 , according to some embodiments of the present application, along the axial direction of the roller 50 , the inner roller 80 includes at least two stacked sub-inner rollers 82 , at least two sub-inner rollers 82 are stacked in the same mounting groove 61 , and at least two sub-inner rollers 82 are made of different materials.

[0070] In this way, the sub-inner rollers 82 made of various materials can be selected to combine the rollers 50 , and the rollers 50 having a linear expansion coefficient closer to the linear expansion coefficient of the cylinder 10 can be combined.

[0071] Alternatively, the material of the one of at least two inner rollers 82 in the same mounting groove 61 that is farthest from the inner ring 64 is a wear-resistant material, that is, the outermost inner roller 82 is set to a wear-resistant material, so as to improve the wear resistance of the corresponding end of the roller 50. For example, rollers 50 are set at both ends of the roller 50 in the axial direction, and the outermost sub-roller 50 of each roller 50 is made of a wear-resistant material, so that both ends of the roller 50 in the axial direction have good wear resistance. At the same time, the inner layer sub-roller 50 that is closer to the inner ring 64 in the same mounting groove 61 can be selected from a material with a suitable linear expansion coefficient to match the roller 50 whose linear expansion coefficient is closer to the linear expansion coefficient of the cylinder 10, so that the linear expansion coefficient of the roller 50 can be guaranteed and the wear resistance of the axial end of the roller 50 can be improved.

[0072] According to some embodiments of the present application, the present application further provides a roller 50 as described in any of the above embodiments. The roller 50 includes an outer roller 60 and at least one inner roller 80, the outer roller 60 is annular, and at least one mounting groove 61 is provided on the inner circumference of the outer roller 60, and at least one inner roller 80 is respectively sleeved in at least one mounting groove 61, so that the inner roller 80 is nested inside the outer roller 60. Among them, the linear expansion coefficient of one of the outer roller 60 and any inner roller 80 is greater than the linear expansion coefficient of the cylinder 10, and the linear expansion coefficient of the other is less than the linear expansion coefficient of the cylinder 10.

[0073] In this way, the inner roller 80 and the outer roller 60 are nested and assembled together, and compared with the linear expansion coefficient of the cylinder 10, the linear expansion coefficient of one of the inner roller 80 and the outer roller 60 is larger, and the linear expansion coefficient of the other is smaller. After the inner roller 80 and the outer roller 60 are combined, a roller 50 with a linear expansion coefficient close to that of the cylinder 10 can be matched. Therefore, when the compressor 100 is working, the consistency of the axial thermal expansion of the roller 50 and the cylinder 10 along the roller 50 is better, so that the assembly gap between the roller 50 and the axial flange 30 of the cylinder 10 remains stable, preventing the assembly gap between the roller 50 and the flange 30 from becoming too large or too small after thermal expansion, preventing the refrigerant in the cylinder 10 from leaking or the roller 50 from getting stuck, and improving the reliability of the compressor 100.

[0074] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A roller, characterized in that: Used to be sleeved in the cylinder of the compressor, and includes: An outer roller, the outer roller is annular, and at least one mounting groove is formed on the inner circumference of the outer roller; at least one inner roller, wherein the at least one inner roller is respectively sleeved in the at least one mounting groove; wherein the linear expansion coefficient of one of the outer roller and any one of the inner rollers is greater than the linear expansion coefficient of the cylinder, and the linear expansion coefficient of the other is less than the linear expansion coefficient of the cylinder; The outer roller includes an outer ring and an inner ring disposed on the inner circumference of the outer ring. The height of the inner ring along the axial direction of the roller is smaller than the height of the outer ring. The mounting groove is defined between the inner ring and the outer ring.

2. The roller according to claim 1, characterized in that The average density of the outer roller and all of the inner rollers is less than the density of the cylinder.

3. The roller according to claim 1 or 2, characterized in that: The mounting grooves are formed on one or both axial sides of the inner ring, and the number of the inner rollers matches the number of the mounting grooves.

4. The roller according to claim 1 or 2, characterized in that: In a natural state, along the axial direction of the roller, there is an assembly gap between the roller and the flange at the axial end of the cylinder; Based on the fact that the sum of the linear expansion of the inner ring and the inner roller is consistent with the linear expansion of the cylinder, and the sum of the inner ring height, the height of all the inner rollers and the assembly clearance is equal to the cylinder height, the height of the inner ring and all the inner rollers along the axial direction of the roller in the natural state is determined.

5. The roller according to claim 4, characterized in that During the operation of the compressor, the final temperatures of the roller and the cylinder are the same, the material of all the inner rollers is the same, the linear expansion coefficient of the cylinder is α, the linear expansion coefficient of the outer roller is α1, and the linear expansion coefficient of the inner roller is α2; Along the axial direction of the roller, the height of the inner ring is H1, the height of all the inner rollers on the outer roller is H2, the height of the cylinder is H, the assembly clearance is c, H1=(Hα- Hα2+cα2) / (α1-α2), H2=(Hα- Hα1+cα1) / (α2-α1).

6. The roller according to claim 4, characterized in that The ratio of the thermal diffusivity of the outer roller to the thermal diffusivity of the cylinder is 0.8-1.2, and the ratio of the thermal diffusivity of the inner roller to the thermal diffusivity of the cylinder is 0.8-1.

2.

7. The roller according to claim 3, characterized in that The inner ring has mounting grooves formed on opposite sides of the axial direction. There are two inner rollers, which are respectively arranged in the two mounting grooves. The two inner rollers are made of different materials, and one of the two inner rollers is made of wear-resistant material.

8. The roller according to claim 3, characterized in that Along the axial direction of the roller, the inner roller includes at least two stacked sub-inner rollers, at least two of the sub-inner rollers are stacked in the same mounting groove, and at least two of the sub-inner rollers are made of different materials, and the material of the one farthest from the inner ring among the at least two sub-inner rollers in the same mounting groove is wear-resistant material.

9. The roller according to claim 1 or 2, characterized in that: The cylinder is made of cast iron, the outer roller is made of alumina ceramics, and at least one inner roller is made of aluminum alloy.

10. The roller according to claim 1 or 2, characterized in that: The cylinder is made of cast iron, the linear expansion coefficient of the outer roller is greater than the linear expansion coefficient of the cylinder, and the linear expansion coefficient of at least one inner roller is less than the linear expansion coefficient of the cylinder; In a natural state, along the axial direction of the roller, the inner roller having a linear expansion coefficient smaller than the linear expansion coefficient of the cylinder is arranged to protrude from the outer roller.

11. The roller according to claim 10, characterized in that The cylinder is made of cast iron, the outer roller is made of grey cast iron, and the inner roller is made of alumina ceramics.

12. A compressor, characterized in that: It comprises a cylinder, a flange and the roller according to any one of claims 1 to 11, wherein the roller is eccentrically arranged in the cylinder and the flange is arranged at the end of the cylinder; when the compressor is working, the assembly clearance between the roller and the flange along the axial direction of the roller is within a preset range.

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