Crankshaft, pump body oil way structure and compressor

Abstract

The invention provides a crankshaft, a pump body oil way structure and a compressor. The crankshaft comprises a long shaft, an eccentric part and a short shaft which are sequentially arranged in the axial direction. An oil suction hole and a vent hole which extend from the end face of the short shaft to the long shaft are formed in the crankshaft, one end of the oil outlet is communicated with the oil suction hole, and the other end of the oil outlet is opened in the peripheral face of the long shaft; the crankshaft is further provided with a transverse oil hole, the transverse oil hole extends in the radial direction, one end of the transverse oil hole is communicated with the oil suction hole, the other end of the transverse oil hole is opened in the peripheral face of the eccentric part, and an oil groove extending in the axial direction is formed in the position, provided with the transverse oil hole, of the peripheral face of the eccentric part. According to the crankshaft, the pump body oil way structure and the compressor, efficient lubrication is ensured, meanwhile, the shafting rigidity and the operation efficiency are remarkably improved, and cooperative gain is achieved.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more specifically, to a crankshaft, pump body oil circuit structure, and compressor. Background Technology

[0002] Rolling rotor compressors are widely used in air conditioning, refrigeration and other fields due to their compact structure and reliable operation. In compressor design, reducing the crankshaft diameter is a key technology for reducing friction losses and expanding the design space of high-efficiency pump bodies (such as increasing eccentricity to increase displacement), which can significantly optimize compressor energy efficiency and performance.

[0003] However, a smaller shaft diameter leads to a decrease in crankshaft bending stiffness, and under complex loads, the deformation of the eccentric portion intensifies, causing the matching piston to tilt. Piston tilting compromises the sealing of the working chamber, resulting in axial and radial leakage, severely reducing volumetric efficiency and negating the theoretical benefits of a smaller shaft diameter.

[0004] In existing technologies, crankshaft structures typically employ relief grooves at the roots of the long and short shafts to establish lubrication channels, with radial transverse oil holes machined within them. The transverse oil holes in the upper and lower relief grooves connect with the axial oil passages in the eccentric portion of the crankshaft, forming the pump body lubrication circuit to provide lubrication and cooling for the compressor's moving components (such as bearings and pistons). However, due to limitations in machining processes (drilling), the width of the relief grooves on the long and short shafts must be greater than the diameter of the transverse oil holes. This results in the weakest area of ​​crankshaft rigidity being concentrated at the relief grooves and transverse oil holes. That is, as the shaft diameter decreases, the rigidity in this area further weakens, exacerbating shaft deformation and leakage problems. Simultaneously, the presence of transverse oil holes also limits the potential for increased rigidity in crankshafts with smaller diameters, failing to fully leverage the advantages of the smaller diameter design.

[0005] As the shaft diameter decreases, the contradictions in this weak point become increasingly prominent: on the one hand, deformation is more concentrated in this area, exacerbating the risk of leakage; on the other hand, the size of the relief groove, which must be maintained to preserve the transverse oil hole, effectively limits the space for further reduction in shaft diameter. Traditional oil circuit structure has become a major bottleneck restricting the full realization of the technological advantages of small shaft diameters.

[0006] Therefore, there is an urgent need for a technical solution that can retain the advantages of low friction and large eccentricity design space of a small-diameter crankshaft, while also enhancing crankshaft rigidity and ensuring normal oil supply to the pump body, in order to solve the defects of the existing structure.

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

[0008] In view of the problems in the prior art, the purpose of the present invention is to provide a crankshaft, a pump body oil circuit structure and a compressor. The structural optimization of the crankshaft overcomes the inherent weaknesses of a crankshaft with a thin shaft diameter, and the overall rigidity of the crankshaft is improved.

[0009] Specifically, in the first aspect of the present invention, a crankshaft is provided, which includes a long shaft, an eccentric part and a short shaft arranged in sequence along the axial direction; An oil suction hole and a vent hole extending from the end face of the short shaft towards the long shaft are arranged inside the crankshaft. One end of the vent hole is communicated with the oil suction hole, and the other end opens on the outer peripheral surface of the long shaft; The crankshaft is further provided with a transverse oil hole, which extends radially. One end of the transverse oil hole is communicated with the oil suction hole, and the other end opens on the outer peripheral surface of the eccentric part. And an oil groove extending along the axial direction is arranged at the outer peripheral surface of the eccentric part where the transverse oil hole 121 is provided.

[0010] According to the first aspect of the present invention, the crankshaft is made of a material with an elastic modulus greater than or equal to 200 GPa.

[0011] According to the first aspect of the present invention, a first relief groove is provided at the root of the long shaft, and the width of the first relief groove is M1; A second relief groove is provided at the root of the short shaft, and the width of the second relief groove is M2; Satisfy: 0.5 mm < M1 < 2.8 mm, 0.5 mm < M2 < 2.8 mm.

[0012] According to the first aspect of the present invention, the diameter of the long shaft is d1, and the diameter of the short shaft is d2, satisfying: 8 mm < d1 < 13 mm, 6 mm < d2 < 11 mm, and / or

[0013] The diameter of the transverse oil hole is D, satisfying: D > 3.5 mm.

[0014] According to the first aspect of the present invention, the oil groove is a straight groove, an inclined groove or an arc groove.

[0015] According to the first aspect of the present invention, the depth of the oil groove in the radial direction is T, satisfying: 1.2 mm < T < 5 mm.

[0016] According to the first aspect of the present invention, with the axis of the crankshaft as the center, the circumferential extension angle of the oil groove is between 20° and 80°.

[0017] In the second aspect of the present invention, a pump body oil circuit structure is provided, which includes a pump body assembly and the crankshaft described in the first aspect; The pump body assembly includes an upper cylinder head, a cylinder block, a lower cylinder head and a piston. The upper cylinder head, the cylinder block and the lower cylinder head are sequentially connected to enclose a cavity; The crankshaft passes through the pump body assembly, the eccentric part is located in the cavity and is fitted with a piston, and the piston and the eccentric part are in clearance fit.

[0018] According to a second aspect of the invention, the oil groove is used to deliver lubricating oil to the mating surfaces of the upper cylinder head and the cylinder body and the lower cylinder head and the cylinder body by means of centrifugal force and the squeezing action of the piston reciprocating motion when the crankshaft rotates.

[0019] A third aspect of the present invention provides a compressor including the pump body oil passage structure described in the second aspect.

[0020] The crankshaft, pump body oil circuit structure, and compressor provided by this invention, compared with existing technologies, significantly improve shaft rigidity and operating efficiency while ensuring efficient lubrication, achieving synergistic gains in technical effects. Specifically, this is manifested as follows: By eliminating the oil holes conventionally located in the relief groove area and narrowing the widths of the first and second relief grooves (M1, M2 < 2.8mm), stress concentration and cross-sectional weakening caused by openings and wide grooves are effectively avoided. This design increases the overall rigidity of the crankshaft by approximately 30%-50%, significantly suppressing shaft deformation under high-speed, high-load conditions. The reduction in shaft deformation directly leads to reduced gas leakage, improving the compressor's volumetric efficiency and operational stability.

[0021] An independent oil supply path is entirely dominated by the eccentric section. Lubricating oil enters the eccentric section through the suction port and is then transported via the transverse oil hole to the deepened oil groove (T > 1.2mm) of the eccentric section. Under the combined squeezing action of the crankshaft's centrifugal force and the piston's reciprocating motion, the lubricating oil in the oil groove can be efficiently transported upwards and downwards through the fit clearance between the piston and the eccentric section, directly reaching the bearing mounting areas and friction pair surfaces of the upper and lower cylinder heads. This design eliminates the reliance on auxiliary oil holes in the traditional relief groove area, resulting in a simpler and more efficient oil circuit logic, increasing oil delivery by more than 20%, and ensuring sufficient lubrication and cooling of key friction pairs.

[0022] The aforementioned structural optimizations address the inherent weaknesses of small-diameter crankshafts while simultaneously increasing overall crankshaft rigidity, making even smaller shaft diameters possible. Smaller shaft diameters can reduce bearing frictional power consumption by 10%-15%. Furthermore, the increased shaft rigidity allows for a 5%-10% increase in eccentricity of the eccentric portion under the same reliability conditions, directly increasing the compressor's single-revolution displacement. The reduction in frictional losses and the increase in displacement ultimately drive a significant improvement in the compressor's coefficient of performance (COP), achieving overall efficiency optimization within the small-diameter architecture. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without inventive effort. Furthermore, the drawings are merely illustrative diagrams of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0024] Figure 1 This is a schematic diagram of the crankshaft structure according to an embodiment of the present invention; Figure 2 This is a partially enlarged view of a crankshaft according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the pump body oil circuit structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the oil supply path of the pump body oil circuit structure according to an embodiment of the present invention. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present invention can be modified or changed according to different viewpoints and application systems without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0026] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can readily implement it. The present invention can be embodied in many different forms and is not limited to the embodiments described herein.

[0027] In the representation of this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics represented in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate different embodiments or examples represented in this invention, as well as features of different embodiments or examples, without contradiction.

[0028] To clearly illustrate the present invention, components unrelated to the description are omitted, and the same or similar constituent elements throughout the specification are given the same reference numerals.

[0029] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Furthermore, when it is said that a device "comprises" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather implies that other constituent elements may be included.

[0030] When we say that a device is "above" another device, this can mean that it is directly above the other device, or it can mean that other devices are present in between. Conversely, when we say that a device is "directly" "above" another device, there are no other devices present in between.

[0031] Although the terms first, second, etc., are used in some instances herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0032] The technical terms used herein are for reference only to specific embodiments and are not intended to limit the invention. The singular form used herein includes the plural form unless the statement explicitly indicates otherwise. The word "comprising" as used in this specification means to specify a particular characteristic, region, integer, step, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components.

[0033] Unless otherwise defined in this application, all terms, including technical and scientific terms as used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with relevant technical literature and the content of this present instruction, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0034] The crankshaft, pump body oil circuit structure, and compressor of the present invention are 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 the present invention.

[0035] This invention provides a crankshaft, Figure 1 and Figure 2 The images shown are a schematic diagram and a partial enlarged view of a crankshaft according to an embodiment of the present invention. The crankshaft 1 includes a long shaft 11, an eccentric portion 12 and a short shaft 13 arranged sequentially along the axial direction.

[0036] The crankshaft 1 has an oil suction hole 111 and a vent hole 1111 extending from the end face of the short shaft 13 to the long shaft 11 inside. Figure 1 (The viewing angle is not shown), the vent 1111 extends radially along the long axis, one end of the vent 1111 communicates with the oil suction hole 111, and the other end opens onto the outer circumferential surface of the long axis 11. See [reference needed]. Figure 3 .

[0037] The crankshaft 1 is also provided with a transverse oil hole 121, which extends radially along the eccentric portion 12. One end of the transverse oil hole 121 communicates with the oil suction hole 111, and the other end opens onto the outer peripheral surface of the eccentric portion 12. An axially extending oil groove 122 is provided on the outer peripheral surface of the eccentric portion 12 corresponding to the opening of the transverse oil hole 121. That is, an axially extending oil groove 122 is also provided on the outer peripheral surface of the eccentric portion 12 at the position corresponding to the opening of the transverse oil hole 121.

[0038] In the present invention, the crankshaft is made of a material with an elastic modulus greater than or equal to 200 GPa, which can be alloy structural steel (such as 20Cr steel, 40Cr steel), high-quality carbon structural steel (such as 45 steel), etc. In one embodiment, the diameter of the long shaft 11 is d1, where 8 mm < d1 < 13 mm. The diameter of the short shaft 13 is d2, where 6 mm < d2 < 11 mm. This crankshaft adopts a thin shaft diameter design, and no oil holes are provided at the roots of the long shaft 11 and the short shaft 13, thus eliminating the weakening of the crankshaft rigidity caused by opening oil holes at these locations.

[0039] To meet the assembly requirements, a first relief groove 112 can be provided at the root of the long shaft 11. The width of the first relief groove 112 is M1, and 0.5 mm < M1 < 2.8 mm. Similarly, a second relief groove 131 can be provided at the root of the short shaft 13. The width of the second relief groove 131 is M2, and 0.5 mm < M2 < 2.8 mm. In other words, the crankshaft of the present invention only retains narrow relief grooves that meet the basic processing and assembly requirements in the root regions of the long shaft and the short shaft, while completely canceling the oil hole setting in the traditional structure. This design significantly enhances the structural integrity of the crankshaft root, increases the rigidity of the weakest region of the crankshaft by about 30% - 50%, effectively improves the overall rigidity, and thus can greatly suppress the shafting deformation (the deformation of the eccentric part can be reduced by more than 25%) under high-speed and high-load conditions, avoid piston tilt, and further reduce end face and radial leakage, improving the volumetric efficiency and operating stability of the compressor.

[0040] Furthermore, for the oil groove 122 provided on the outer peripheral surface of the eccentric part 12, its side wall is parallel to the crankshaft axis. The cross-sectional shape of this oil groove 122 can be a straight groove, an inclined groove or an arc groove. Among them, a straight groove means that the projection of the oil groove 122 on the end face of the eccentric part 12 is a straight line and perpendicular to a certain radial line of the eccentric part; an inclined groove means that its projection is a straight line but not perpendicular to any radial line; an arc groove means that its projection is a curved shape. Preferably, the depth T of the oil groove 122 in the radial direction satisfies: 1.2 mm < T < 5 mm. Based on the crankshaft axis, the circumferential extension angle of the oil groove 122 can be within the range of 20° to 80°, such as 30°, 40° or 50°, etc.

[0041] To improve the oil supply capacity of the lubrication system and ensure sufficient lubrication flow, in a preferred embodiment, the diameter D of the transverse oil hole 121 satisfies: D > 3.5 mm. By providing an axial oil groove 122 intersecting with the transverse oil hole 121 on the outer periphery of the eccentric part 12 and appropriately increasing the aperture of the transverse oil hole 121, the present invention can still ensure the stability and efficiency of the lubricating oil path supply with only one transverse oil hole structure.

[0042] The present invention also provides a pump body oil path structure. Figure 3This is a schematic diagram of the pump body oil circuit structure according to an embodiment of the present invention. The pump body oil circuit structure includes a pump body assembly and a crankshaft 1 in the first aspect. The pump body assembly includes an upper cylinder head 21, a cylinder block 22, a lower cylinder head 23, and a piston 24. The upper cylinder head 21, cylinder block 22, and lower cylinder head 23 are connected in sequence and form a cavity. The crankshaft 1 passes through the pump body assembly, and the eccentric part 12 is located in the cavity and fitted with the piston 24. The piston 24 and the eccentric part 12 are in clearance fit. When the crankshaft 1 rotates, the oil groove 122 can effectively deliver lubricating oil to key friction pair areas such as the contact surfaces of the upper cylinder head 21 and the cylinder block 22, and the contact surfaces of the lower cylinder head 23 and the cylinder block 22, by means of centrifugal force and the squeezing action generated by the reciprocating motion of the piston 24.

[0043] Figure 4 This is a schematic diagram of the oil supply path of a pump body oil circuit structure according to an embodiment of the present invention. Specifically, the oil supply path is as follows: the lubricating oil in the compressor oil sump flows through the oil suction hole 111 of the crankshaft long shaft 11 to the transverse oil hole 121 of the eccentric part 12, then enters the oil groove 122 on the outer periphery of the eccentric part 12, and finally, along the fitting clearance between the crankshaft eccentric part 12 and the piston 24, it is delivered upwards and downwards to the bearing mounting areas and related friction surfaces of the upper cylinder head 21 and the lower cylinder head 23, respectively. This lubrication path design is simple and efficient, increasing the oil delivery volume by more than 20% compared to the traditional structure, thereby ensuring that the key friction pairs receive sufficient lubrication and cooling.

[0044] This invention also provides a compressor, including the aforementioned pump body oil circuit structure. The compressor can be single-cylinder, double-cylinder, or multi-cylinder. Due to the adoption of the aforementioned structurally optimized small-diameter crankshaft, the overall rigidity of the crankshaft is improved, and the smaller shaft diameter helps reduce bearing frictional power consumption by approximately 10%-15%. Simultaneously, the enhanced shaft rigidity allows for a 5%-10% increase in the eccentricity of the eccentric portion 12 while maintaining the same reliability, directly increasing the compressor's single-revolution displacement. The reduction in frictional loss and the increase in displacement work together to significantly optimize the compressor's coefficient of performance (COP), maximizing overall efficiency under the small-diameter architecture.

[0045] 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.

[0046] 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 scope of protection of the present invention.

Claims

1. A crankshaft, characterized by The crankshaft comprises a long shaft, an eccentric part and a short shaft arranged in sequence along an axial direction; The crankshaft is internally provided with an oil suction hole extending from an end surface of the short shaft to the long shaft and a vent hole, one end of the vent hole being in communication with the oil suction hole and the other end being open to an outer circumferential surface of the long shaft; The crankshaft is further provided with a transverse oil hole extending in a radial direction, one end of the transverse oil hole being in communication with the oil suction hole and the other end being open to an outer circumferential surface of the eccentric part, and the outer circumferential surface of the eccentric part provided with the transverse oil hole is provided with an oil groove extending in an axial direction.

2. The crankshaft of claim 1 wherein, The crankshaft is made of a material with an elastic modulus greater than or equal to 200 GPa.

3. The crankshaft of claim 1 wherein, The long shaft is provided at a root portion thereof with a first tool withdrawal groove, the first tool withdrawal groove having a width of M1; The short shaft is provided at a root portion thereof with a second tool withdrawal groove, the second tool withdrawal groove having a width of M2; The following conditions are met: 0.5 mm < M1 < 2.8 mm, 0.5 mm < M2 < 2.8 mm.

4. The crankshaft of claim 1 wherein, The long shaft has a diameter of d1 and the short shaft has a diameter of d2, and the following conditions are met: 8 mm < d1 < 13 mm, 6 mm < d2 < 11 mm, and / or The transverse oil hole has a diameter of D, and the following condition is met: D > 3.5 mm.

5. The crankshaft of claim 1 wherein, The oil groove is a straight groove, an inclined groove or an arc-shaped groove.

6. The crankshaft of claim 5 wherein, The oil groove has a depth T in a radial direction, and the following condition is met: 1.2 mm < T < 5 mm.

7. The crankshaft of claim 5 wherein, The oil groove extends in a circumferential direction at an angle of 20° to 80° with respect to the axis of the crankshaft.

8. A pump body oil passage structure characterized by comprising: The pump body assembly comprises an upper cylinder head, a cylinder body, a lower cylinder head and a piston, the upper cylinder head, the cylinder body and the lower cylinder head being connected in sequence and surrounding a cavity; The crankshaft is arranged in the pump body assembly, the eccentric part is located in the cavity and is sleeved with the piston, and the piston is in clearance fit with the eccentric part. The oil groove is used to deliver lubricating oil to the abutting surfaces of the upper cylinder head and the cylinder body and the abutting surfaces of the lower cylinder head and the cylinder body by centrifugal force and extrusion of reciprocating movement of the piston when the crankshaft rotates.

9. The pump body oil passage structure according to claim 8, characterized by The pump body oil passage structure comprises the pump body assembly and the crankshaft according to any one of claims 1 to 7.

10. A compressor characterized by, The pump body oil passage structure comprises the pump body assembly and the crankshaft according to any one of claims 1 to 7.

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