Crankshaft and compressor

Abstract

The utility model provides a kind of crankshaft and compressor, the crankshaft includes long shaft, eccentric part and short shaft connected in turn;The end face of the eccentric part is provided with thrust surface and sets up the sealing surface of the outer periphery of thrust surface, the sealing surface is lower than the thrust surface, and the sealing surface is provided with at least one recess;The projection of the recess on end face includes opening end and bottom end, the width of the opening end is greater than the width of the bottom end, and the opening end setting direction is same with the rotation direction of the crankshaft.The utility model's crankshaft is provided with sealing surface in its one end face, and sealing surface is provided with multiple recesses, and the opening end setting direction is same with the rotation direction of the crankshaft, in the operation process of crankshaft, sealing surface can form stable oil film thickness, not only can reduce the friction of sealing surface and cylinder cover inner surface, but also can reduce end face leakage.

Description

Technical Field

[0001] This utility model relates to the field of compressor technology, specifically to a crankshaft and a compressor. Background Technology

[0002] In the structural design of rotary compressors, reducing the compressor's exhaust resistance is one of the main research directions for improving pump efficiency. Reducing compressor exhaust resistance mainly involves the following aspects: enlarging the cylinder head exhaust port and the corresponding oblique cut (DV port) on the cylinder; optimizing and improving the rigidity and shape of the exhaust valve plate and baffle; optimizing the exhaust passage; optimizing the muffler cavity shape; optimizing the exhaust valve seat shape, etc. However, these optimizations have many uncertainties. For example, enlarging the cylinder head exhaust port and the corresponding DV port on the cylinder will increase the cylinder clearance volume, which is detrimental to gas compression; optimizing the muffler cavity shape also needs to consider the impact of noise and other indicators. Based on this, an optimization scheme that moves the exhaust port and DV port axially inward simultaneously can reduce the gas exhaust resistance, and the DV port will decrease accordingly during the inward movement, further reducing the cylinder clearance volume. However, during the inward movement of the DV port and exhaust port, the change in the relative position of the piston and exhaust port can cause gas leakage and other problems, which in many cases limits the distance that the DV port and exhaust port can move inward. To address the above technical issues, the current solution involves designing a crankshaft sealing structure in the eccentric portion of the crankshaft, which effectively solves the leakage problem caused by the inward relocation of the exhaust port. However, while solving the leakage problem, the location and shape of the sealing structure bring corresponding negative impacts to the compressor. First, the sealing structure increases the area of ​​the eccentric portion, thus increasing the potential friction area between the eccentric portion and the cylinder head. During operation, the eccentric portion may deform under stress, leading to friction between the sealing structure and the cylinder head, increasing the compressor's input force. Second, due to the 10μm to 15μm height difference between the sealing structure and the thrust surface of the eccentric portion, leakage may occur under certain operating conditions due to this height difference, resulting in a decrease in compressor cooling capacity.

[0003] To address the potential technical problems caused by the above crankshaft sealing structure, an "opening" shaped groove structure is provided on the sealing structure along the direction of crankshaft rotation, based on the crankshaft sealing structure. The opening direction of the groove structure is the direction of crankshaft rotation during compressor operation.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this utility model, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] To address the problems in the prior art, the purpose of this utility model is to provide a crankshaft and a compressor. The crankshaft has a sealing surface on one end face, and the sealing surface has multiple grooves with open ends located at the front end of the crankshaft in the direction of rotation. The grooves form a stable oil film thickness on the sealing surface of the crankshaft, reducing friction loss. The stable oil film thickness on the sealing surface can also fill the height difference between the sealing surface and the thrust surface, forming an end face sealing structure to prevent leakage at the end face.

[0006] The first aspect of this utility model provides a crankshaft, the crankshaft comprising a long shaft, an eccentric portion and a short shaft connected in sequence;

[0007] The end face of the eccentric part is provided with a thrust surface and a sealing surface provided on the outer periphery of the thrust surface. The sealing surface is lower than the thrust surface and the sealing surface is provided with at least one groove.

[0008] The projection of the groove on the end face includes an open end and a bottom end. The width of the open end is greater than the width of the bottom end, and the opening end is oriented in the same direction as the rotation direction of the crankshaft.

[0009] According to a first aspect of the present invention, the projection of the groove on the end face is V-shaped, herringbone-shaped, or arc-shaped.

[0010] According to a first aspect of the present invention, the end face of the eccentric portion is provided with a plurality of grooves, wherein the plurality of grooves are a combination of V-shaped grooves, herringbone grooves or arc-shaped grooves.

[0011] According to a first aspect of the present invention, the width of the opening end is L, which satisfies: (d2-d1) / 6≤L≤(d2-d1) / 3, where d1 is the inner diameter of the sealing surface and d2 is the outer diameter of the sealing surface.

[0012] According to a first aspect of the present invention, the projected width of the groove on the end face is S, which satisfies: 0.1mm≤S≤0.3mm.

[0013] According to a first aspect of the present invention, the depth of the groove along the crankshaft axis is h, satisfying: 0.2mm≤h≤0.4mm.

[0014] According to a first aspect of the present invention, the opening angle of the projection of the groove on the end face is θ, which satisfies 30°≤θ≤180°.

[0015] According to a first aspect of the present invention, the spacing between two adjacent grooves is the same.

[0016] The second aspect of this utility model provides a compressor, including a cylinder head, a cylinder, a piston, and the crankshaft described in the first aspect.

[0017] According to a second aspect of the present invention, the cylinder head is provided with an exhaust port;

[0018] The sealing surface of the crankshaft and the end face of the piston form a continuous surface;

[0019] When the crankshaft rotates, the continuous surface covers the projection of the exhaust port onto the end face where the sealing surface of the crankshaft is located.

[0020] Compared with the prior art, the crankshaft of this utility model has a sealing surface on one end face, and the sealing surface has a groove with the opening end facing the same direction as the crankshaft rotation direction. During crankshaft rotation, the opening end of the groove facing the same direction as the crankshaft rotation direction R can make the groove have a better guiding effect, and the oil will more easily accumulate in the groove. The groove filled with lubricating oil makes the crankshaft sealing surface generate a stable oil film thickness. The stable oil film thickness can generate some oil film pressure. When the eccentric part of the crankshaft is subjected to axial deformation, due to the existence of oil film pressure, the crankshaft sealing surface generates a force opposite to the direction of the eccentric part's tilting deformation to support the eccentric part, so that the sealing surface does not contact the cylinder head, reducing friction loss. Attached Figure Description

[0021] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0022] Figure 1 This is a partial side view of a crankshaft according to an embodiment of the present invention;

[0023] Figure 2 This is a cross-sectional view of the cylinder of the compressor according to the first embodiment of the present invention;

[0024] Figure 3 This is a cross-sectional view of the groove in the first embodiment of the present invention;

[0025] Figure 4 This is a cross-sectional view of the cylinder of the compressor according to the second embodiment of the present invention;

[0026] Figure 5 This is a cross-sectional view of the groove in the second embodiment of the present invention. Detailed Implementation

[0027] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0028] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and settings are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or settings discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0031] The structure of the crankshaft and compressor of this utility model is further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments are not intended to limit the scope of protection of this utility model.

[0032] To solve the above-mentioned technical problems, this utility model provides a crankshaft. Figure 1This is a partial side view of a crankshaft according to an embodiment of the present invention. Specifically, the crankshaft 1 includes a long shaft (not fully shown in the figure), an eccentric portion 11, and a short shaft 12 connected in sequence; the short shaft 12 is provided with an oil hole 121. When the crankshaft 1 is used in a compressor, the eccentric portion 11 is located within the space enclosed by the cylinder and the cylinder head, and a piston is fitted onto the eccentric portion 11. The end face of the eccentric portion 11 that mates with the cylinder head is provided with a thrust surface 111 and a sealing surface 112 on the outer periphery of the thrust surface 111. The thrust surface 111 is used for clearance fitting with the cylinder head to prevent axial movement of the crankshaft 1. The sealing surface 112 is lower than the thrust surface 111, and the sealing surface 112 is provided with at least one groove 1121. The projection of the groove 1211 on the end face includes an open end and a bottom end. The width of the open end is greater than the width of the bottom end, and the direction of the open end is the same as the rotation direction of the crankshaft.

[0033] This utility model also provides a compressor, including a cylinder head, a cylinder 9, a piston 8, and a crankshaft 1. The structure of the crankshaft's sealing surface is further explained below by describing the structure of the crankshaft when applied to a compressor. Figure 2 This is a cross-sectional view of the cylinder of a compressor according to an embodiment of the present invention. The cylinder head (not shown in the figure) is provided with an exhaust port, the projection of which on the end face of the crankshaft sealing surface is shown as point B. The cylinder 9 is provided with a bevel (not shown in the figure), and the compressed gas in the compression chamber of the cylinder 9 is discharged through the bevel and the cylinder head exhaust port. The intersection line of the bevel at this end face of the cylinder should coincide as much as possible with the projection line of the cylinder head exhaust port on the cylinder end face. It is understood that the end face of the crankshaft sealing surface and the cylinder end face are two parallel planes perpendicular to the crankshaft axis.

[0034] The piston 8 is fitted around the outer periphery of the eccentric portion 11 of the crankshaft. The sealing surface 112 of the crankshaft 1 mates with the end face of the piston 8, and their end faces at this point form a continuous surface D, as shown within the elliptical dashed line. When the crankshaft 1 rotates, the continuous surface D covers the projection B of the exhaust port on this end face; more precisely, the continuous surface D completely covers the projection B of the exhaust port falling into the cylinder on this end face. This structure ensures that even when the projection B of the exhaust port falling into the inner diameter of the cylinder 9 is large, it still maintains both smooth exhaust flow and sealing performance at this point.

[0035] The projection of the groove on the sealing surface onto the end face can be V-shaped, herringbone-shaped, or arc-shaped. Figure 3 This is a cross-sectional view of the groove on the sealing surface of the first embodiment of the present invention. It can be seen that the groove 1121a on the sealing surface 112a of the first embodiment is V-shaped, with the two free ends of the V-shape being the open ends of its projection on the end face. The rotation direction R of the crankshaft is as follows... Figure 2As indicated by the arrow, the opening end is oriented in the same direction as the rotation direction R of the crankshaft, i.e., the opening end is located at the front end of the rotation direction R. When the compressor operates and the crankshaft rotates, because the sealing surface 112 is outside the thrust surface 111, the eccentric part 11 of the crankshaft 1 tilts and deforms under the action of gas force. To prevent the sealing surface 112 from rubbing against the inner wall of the cylinder head, thereby increasing friction loss, the sealing surface 112 is lower than the thrust surface 111, and the height difference between the two can be several to tens of micrometers. Due to the height difference between the sealing surfaces 112 and 112, when the lubricating oil from the crankshaft oil hole 121 passes through the sealing surface during crankshaft rotation, the opening end of the groove 1121a is oriented in the same direction as the rotation direction R, which allows the groove 1211a to have a better guiding effect. The oil will more easily accumulate in the groove 1211a, increasing the storage capacity of the lubricating oil, reducing friction at the sealing surface 121a, and meeting the lubrication needs of the equipment for a certain period of time. At the same time, the stable oil film on the sealing surface can fill the height difference between the sealing surface and the thrust surface, forming an end-face sealing structure, and will not cause end-face leakage at the sealing surface.

[0036] When the groove is large, it occupies a large area of ​​the sealing surface, which will affect the reliability of the sealing surface. Conversely, if the groove is small, it is difficult to maintain a stable amount of lubricating oil within it, which will affect the sealing and friction-reducing effects. Preferably, the width (span) L of the projection of the groove 1121a satisfies: (d2-d1) / 6 ≤ L ≤ (d2-d1) / 3, where d1 is the inner diameter of the sealing surface and d2 is the outer diameter of the sealing surface. Simultaneously, the projection width S of the groove 1121a on the end face satisfies: 0.1mm ≤ S ≤ 0.3mm, such as 0.2mm. The depth h of the groove 1121a along the crankshaft axis satisfies: 0.2mm ≤ h ≤ 0.4mm. The opening angle θ of the projection of the groove 1121a on the end face satisfies: 30° ≤ θ ≤ 180°.

[0037] Furthermore, the spacing between two adjacent grooves 1121a is the same, that is, the multiple grooves 1121a are evenly distributed in the circumferential direction. During the crankshaft rotation, when the lubricating oil from the oil hole of the crankshaft eccentric part passes through the sealing surface, due to the evenly distributed groove structure of the sealing surface, some of the lubricating oil will fill the groove, and the groove will be filled with lubricating oil in real time. The groove is filled with lubricating oil, which makes the crankshaft sealing surface generate a stable oil film thickness. The stable oil film thickness can generate some oil film pressure. When the crankshaft eccentric part is subjected to axial deformation, due to the existence of oil film pressure, the crankshaft sealing surface generates a force opposite to the direction of the eccentric part's tilting deformation to support the eccentric part, so that the sealing surface does not contact the cylinder head, reducing friction loss.

[0038] Figure 4 and Figure 5These are cross-sectional views of the cylinder and the groove of the compressor according to the second embodiment of this utility model. In the second embodiment, the groove 1121b on the sealing surface 112b is arc-shaped, or more precisely, the groove 1121b is semi-circular. The depth h, width S, and opening angle θ of the groove 1121b can all be set according to the specific structure of the compressor, ensuring the lubricity, sealing, and machinability of the sealing surface.

[0039] In some other embodiments, the end face of the eccentric portion is provided with multiple grooves of different shapes, that is, the multiple grooves can be a combination of V-shaped grooves, herringbone grooves or arc-shaped grooves.

[0040] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0041] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A crankshaft, characterized in that, The crankshaft includes a long shaft, an eccentric section, and a short shaft connected in sequence; The end face of the eccentric part is provided with a thrust surface and a sealing surface provided on the outer periphery of the thrust surface. The sealing surface is lower than the thrust surface and the sealing surface is provided with at least one groove. The projection of the groove on the end face includes an open end and a bottom end. The width of the open end is greater than the width of the bottom end, and the opening end is oriented in the same direction as the rotation direction of the crankshaft.

2. The crankshaft according to claim 1, characterized in that, The projection of the groove on the end face is V-shaped, herringbone-shaped, or arc-shaped.

3. The crankshaft according to claim 1, characterized in that, The end face of the eccentric part is provided with multiple grooves, and the multiple grooves are a combination of V-shaped grooves, herringbone grooves or arc grooves.

4. The crankshaft according to claim 1, characterized in that, The width of the opening is L, which satisfies: (d2-d1) / 6≤L≤(d2-d1) / 3, where d1 is the inner diameter of the sealing surface and d2 is the outer diameter of the sealing surface.

5. The crankshaft according to claim 1, characterized in that, The projected width of the groove on the end face is S, which satisfies: 0.1mm≤S≤0.3mm.

6. The crankshaft according to claim 1, characterized in that, The depth of the groove along the crankshaft axis is h, which satisfies: 0.2mm≤h≤0.4mm.

7. The crankshaft according to claim 1, characterized in that, The opening angle of the projection of the groove onto the end face is θ, which satisfies 30°≤θ≤180°.

8. The crankshaft according to claim 1, characterized in that, The spacing between two adjacent grooves is the same.

9. A compressor, characterized in that, It includes a cylinder head, a cylinder, a piston, and a crankshaft as described in any one of claims 1 to 8.

10. The compressor according to claim 9, characterized in that, The cylinder head is provided with an exhaust port; The sealing surface of the crankshaft and the end face of the piston form a continuous surface; When the crankshaft rotates, the continuous surface covers the projection of the exhaust port onto the end face where the sealing surface of the crankshaft is located.

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