Crankshaft structure, pump assembly and compressor

Abstract

The application discloses a crankshaft structure, a pump body assembly and a compressor. The crankshaft structure comprises a long shaft part, an eccentric part and a short shaft part which are connected in sequence in the axial direction. The long shaft part comprises a long shaft matching section and a long shaft oil outlet section which are coaxially arranged. The long shaft oil outlet section is arranged close to one end of the eccentric part, and the diameter of the long shaft oil outlet section is larger than that of the long shaft matching section. The short shaft part comprises a short shaft matching section and a short shaft oil outlet section which are coaxially arranged. The short shaft oil outlet section is arranged close to one end of the eccentric part, and the diameter of the short shaft oil outlet section is larger than that of the short shaft matching section. The long shaft oil outlet section and the short shaft oil outlet section are arranged, so that the root strength of the long shaft part close to the eccentric part and the root strength of the short shaft part close to the eccentric part are effectively increased, the bending resistance, the torsional strength and the rigidity of the crankshaft are improved, and the occurrence of the sweep bore failure in the process of starting and frequency increasing of the compressor is avoided. Meanwhile, the noise of the compressor is greatly reduced, and the working performance and the reliability of the compressor are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotor compressors, and in particular relates to a crankshaft structure, a pump body assembly and a compressor. Background Art

[0002] With the development of compressor technology, the requirements for compressor efficiency are constantly increasing; therefore, in the design of rolling rotor compressors, the motor speed is required to be higher and higher, the crankshaft diameter is required to be smaller and smaller, and the eccentricity is required to be larger and larger.

[0003] As attached Figure 1 As shown, in the existing crankshaft structure, a first undercut 11' is generally provided at the root of the long axis 11 near the eccentric portion 13, and a second undercut 12' is generally provided at the root of the short axis 12 near the eccentric portion 13; since the diameters of the first undercut 11' and the second undercut 12' are respectively smaller than the diameters of the long axis 11 and the short axis 12, the bending and torsional strengths of the undercut parts are low; at the same time, a radial oil outlet hole is further provided in the undercut that is connected to the central oil hole on the center of the crankshaft, and the radial oil outlet hole further weakens the rigidity of the long axis and the short axis; a finite element stress analysis of the crankshaft structure during the operation of the rolling rotor compressor is performed, as shown in the attached figure. Figure 2-3 As shown, it can be seen that the positions where the crankshaft structure is subjected to greater stress are the middle of the eccentric portion 13, the position of the long axis portion 11 close to the eccentric portion 13, and the position of the short axis portion 12 close to the eccentric portion 13; secondly, stress concentration occurs at the radial oil outlet hole, and the stress is the largest.

[0004] In summary, due to the provision of a relief groove on the crankshaft structure, the bending and torsional strength of the crankshaft is low, which can easily cause an imbalance in the motor gap and generate electromagnetic tension, leading to the following two phenomena: 1) At the moment the compressor starts, the crankshaft is elastically deformed by force; 2) During the operation of the compressor and the increase in the motor speed, the operating inertia force and inertia moment of the compressor increase; both of the above phenomena can easily cause a collision between the outer circle of the motor rotor shrunk on the long axis and the inner diameter of the motor stator, resulting in a bore sweeping fault; secondly, the swing of the crankshaft will also increase the wear between the crankshaft and the compression assembly, ultimately increasing the noise of the compressor and reducing the working performance and reliability. Summary of the Invention

[0005] In response to the technical problems existing in the prior art, the present invention provides a crankshaft structure, a pump body assembly and a compressor to solve the technical problems in the existing crankshaft structure, such as the low bending and torsional strength of the crankshaft due to the provision of a back-off groove, which in turn causes bore sweeping failures and crankshaft wear, resulting in increased compressor noise and reduced working performance and reliability.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention provides a crankshaft structure, wherein a central oil hole is provided at the center of the crankshaft structure, and the crankshaft structure comprises a long shaft portion, an eccentric portion and a short shaft portion which are sequentially connected in the axial direction;

[0008] The long shaft portion includes a coaxially arranged long shaft mating section and a long shaft oil outlet section; wherein the long shaft oil outlet section is arranged near one end of the eccentric portion, and the diameter of the long shaft oil outlet section is larger than the diameter of the long shaft mating section; a long shaft radial oil outlet hole is provided on the long shaft oil outlet section, and the long shaft radial oil outlet hole is used to connect the surface of the long shaft oil outlet section with the central oil hole;

[0009] The short shaft portion includes a coaxially arranged short shaft mating section and a short shaft oil outlet section; wherein, the short shaft oil outlet section is arranged close to one end of the eccentric portion, and the diameter of the short shaft oil outlet section is larger than the diameter of the short shaft mating section; a short shaft radial oil outlet hole is provided on the short shaft oil outlet section, and the short shaft radial oil outlet hole is used to connect the surface of the short shaft oil outlet section with the central oil hole.

[0010] Furthermore, the surface of the long shaft fitting section is a finely machined surface, and the surface of the long shaft oil outlet section is a rough machined surface;

[0011] The difference between the diameter size of the oil outlet section of the long shaft and the diameter size of the mating section of the long shaft is the same as the grinding allowance of the mating section of the long shaft; wherein, the grinding allowance of the mating section of the long shaft is the grinding allowance reserved for the centerless grinding process of the fine machining of the mating section of the long shaft.

[0012] Furthermore, the surface of the short shaft fitting section is a finely machined surface, and the surface of the short shaft oil outlet section is a rough machined surface;

[0013] The difference between the diameter size of the short shaft oil outlet section and the diameter size of the short shaft mating section is the same as the grinding allowance of the short shaft mating section; wherein, the grinding allowance of the short shaft mating section is the grinding allowance reserved for the centerless grinding process of the short shaft mating section.

[0014] Furthermore, the length of the long shaft oil outlet section is greater than the diameter of the long shaft radial oil outlet hole, and the length of the short shaft oil outlet section is the same as the diameter of the short shaft radial oil outlet hole.

[0015] Furthermore, the length dimension of the oil outlet section of the long shaft satisfies: 1.2f1≥L1≥1.05f1; wherein L1 is the length of the oil outlet section of the long shaft, and f1 is the diameter of the radial oil outlet hole of the long shaft.

[0016] Furthermore, the length dimension of the short shaft oil outlet section satisfies: 1.2f2≥L2≥1.05f2; wherein L2 is the length of the short shaft oil outlet section, and f2 is the diameter of the short shaft radial oil outlet hole.

[0017] The present invention also provides a pump body assembly, comprising a crankshaft, an upper cover, a lower cover, a cylinder and a piston; the crankshaft adopts the above-mentioned crankshaft structure;

[0018] The upper cover seal is arranged on the upper end surface of the cylinder, and the lower cover seal is arranged on the lower end surface of the cylinder; the crankshaft is concentrically assembled in the working chamber of the cylinder;

[0019] Among them, the long axis portion of the crankshaft is inserted into the upper cover inner hole of the upper cover, and the short axis portion of the crankshaft is inserted into the lower cover inner hole of the lower cover; the piston is arranged in the working chamber of the cylinder and is sleeved on the outside of the eccentric portion of the crankshaft.

[0020] Furthermore, the inner hole of the upper cover includes a first inner hole section and a second inner hole section that are concentrically connected; wherein the first inner hole section is arranged away from the upper cover end surface of the upper cover, and the second inner hole section is arranged close to the upper cover end surface of the upper cover;

[0021] The diameter of the inner hole section of the first upper cover is smaller than the diameter of the inner hole section of the second upper cover; the diameter of the inner hole section of the first upper cover matches the diameter of the long shaft matching section, and the diameter of the inner hole section of the second upper cover matches the diameter of the long shaft oil outlet section; the length of the inner hole section of the second upper cover is greater than the length of the long shaft oil outlet section.

[0022] Furthermore, the lower cover inner hole includes a first lower cover inner hole section and a second lower cover inner hole section that are concentrically connected; wherein the first lower cover inner hole section is arranged away from the lower cover end surface of the lower cover, and the second lower cover inner hole section is arranged close to the lower cover end surface of the lower cover;

[0023] The diameter of the inner hole section of the first lower cover is smaller than the diameter of the inner hole section of the second lower cover, the diameter of the inner hole section of the first lower cover matches the diameter of the short shaft matching section, and the diameter of the inner hole section of the second lower cover matches the diameter of the short shaft oil outlet section; the length of the inner hole section of the second lower cover is greater than the length of the short shaft oil outlet section.

[0024] The present invention also provides a compressor, characterized in that it comprises the aforementioned pump body assembly.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a crankshaft structure, a pump body assembly and a compressor, which adopt the method of arranging a long shaft oil outlet section at a position of the long shaft part close to the eccentric part, and designing the diameter of the long shaft oil outlet section to be larger than the diameter of the long shaft matching section, and utilizing the long shaft oil outlet section to perform structural compensation for the root position of the long shaft part close to the eccentric part; secondly, arranging a short shaft oil outlet section at a position of the short shaft part close to the eccentric part, and designing the diameter of the short shaft oil outlet section to be larger than the diameter of the short shaft matching section, and utilizing the short shaft oil outlet section to perform structural compensation for the root position of the short shaft part close to the eccentric part; by arranging the long shaft oil outlet section and the short shaft oil outlet section, the root strength of the long shaft part close to the eccentric part and the root strength of the short shaft part close to the eccentric part are effectively increased, the bending and torsional strength and stiffness of the crankshaft are improved, thereby avoiding the occurrence of chamber sweeping failures during the startup and frequency increase operation of the compressor; at the same time, the noise of the compressor is greatly reduced, and the working performance and reliability of the compressor are ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a crankshaft structure in an existing compressor;

[0028] Figure 2 This is a displacement distribution cloud diagram of the crankshaft structure in the existing compressor;

[0029] Figure 3 This is a cloud diagram of the stress distribution of the crankshaft structure in the existing compressor;

[0030] Figure 4 This is a schematic diagram of the overall structure of the crankshaft structure described in Example 1;

[0031] Figure 5 A schematic diagram of the partial structure of the crankshaft mechanism described in Example 1;

[0032] Figure 6 This is a schematic structural diagram of the upper cover in Example 2;

[0033] Figure 7 Schematic diagram of the structure of the lower cover in Example 2;

[0034] Figure 8 This is a schematic diagram of the compressor structure described in Example 3.

[0035] Among them, 1 crankshaft, 2 upper cover, 3 lower cover, 4 cylinder, 5 piston, 6 slide, 7 spring, 8 motor rotor, 9 motor stator, 10 housing; 11 long shaft portion, 12 short shaft portion, 13 eccentric portion, 14 center oil hole, 11' first undercut groove, 12' second undercut groove; 111 long shaft matching section, 112 long shaft oil outlet section; 1121 long shaft radial oil outlet hole; 121 short shaft matching section, 122 short shaft oil outlet section 122; 1221 short shaft radial oil outlet hole; 21 upper cover end face, 22 upper cover inner hole; 221 first upper cover inner hole section, 222 second upper cover inner hole section; 31 lower cover end face, 32 lower cover inner hole; 321 first lower cover inner hole section, 322 second lower cover inner hole section. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] Example 1

[0038] As attached Figure 4-5 As shown, this embodiment 1 provides a crankshaft structure, wherein a central oil hole 14 is provided at the center of the crankshaft structure; the crankshaft structure includes a long shaft portion 11, an eccentric portion 13 and a short shaft portion 12 which are axially connected in sequence.

[0039] In this embodiment 1, the long shaft portion 11 includes a coaxially arranged long shaft mating section 111 and a long shaft oil outlet section 112, and the long shaft oil outlet section 112 is arranged near one end of the eccentric portion 13; specifically, one end of the long shaft mating section 111 is used to fit and insert into the upper cover inner hole of the pump body upper cover, and extend to the outside of the upper cover inner hole to be connected to the motor assembly in the compressor; the other end of the long shaft mating section 111 is connected to one end of the long shaft oil outlet section 112, and the other end of the long shaft oil outlet section 112 is connected to the first end of the eccentric portion 13.

[0040] A long shaft radial oil outlet hole 1121 is provided on the long shaft oil outlet section 112, and the long shaft radial oil outlet hole 1121 is used to connect the surface of the long shaft oil outlet section 112 with the central oil hole 14; specifically, one end of the long shaft radial oil outlet hole 1121 is connected with the surface of the long shaft oil outlet section 112, and the other end of the long shaft radial oil outlet hole 1121 extends along the radial direction of the long shaft oil outlet section 112 toward its axial direction, and is connected with the central oil hole 14.

[0041] The surface of the long shaft mating section 111 is a finely machined surface, and the surface of the long shaft oil outlet section 112 is a rough-machined surface; the difference between the diameter d1' of the long shaft oil outlet section 112 and the diameter d1 of the long shaft mating section 111 is the same as the grinding allowance of the long shaft mating section 111; wherein, the grinding allowance of the long shaft mating section 111 is the grinding allowance reserved for the fine-machining centerless grinding process of the long shaft mating section 111; that is, d1'-d1=the grinding allowance of the long shaft mating section 111; preferably, the difference between the diameter d1' of the long shaft oil outlet section 112 and the diameter d1 of the long shaft mating section 111 is 0.2-0.4mm; the length L1 of the long shaft oil outlet section 112 is greater than the diameter f1 of the long shaft radial oil outlet hole 1121; preferably, the length L1 of the long shaft oil outlet section 112 satisfies: 1.2f1≥L1≥1.05f1.

[0042] In this embodiment 1, the short shaft portion 12 includes a coaxially arranged short shaft mating section 121 and a short shaft oil outlet section 122, and the short shaft oil outlet section 122 is arranged close to one end of the eccentric portion 13; specifically, one end of the short shaft mating section 121 is used to fit and insert into the lower cover inner hole of the pump body lower cover, and the other end of the short shaft mating section 121 is connected to one end of the short shaft oil outlet section 122, and the other end of the short shaft oil outlet section 122 is connected to the second end of the eccentric portion 13.

[0043] A short shaft radial oil outlet hole 1221 is provided on the short shaft oil outlet section 122, and the short shaft radial oil outlet hole 1221 is used to connect the surface of the short shaft oil outlet section 122 with the central oil hole 14; specifically, one end of the short shaft radial oil outlet hole 1221 is connected with the surface of the short shaft oil outlet section 122, and the other end of the short shaft radial oil outlet hole 1221 extends along the radial direction of the short shaft oil outlet section 122 toward its axial direction and is connected with the central oil hole 14.

[0044] The surface of the stub mating section 121 is a finish-machined surface, while the surface of the stub oil outlet section 122 is a rough-machined surface. The difference between the diameter d2' of the stub oil outlet section 122 and the diameter d2 of the stub mating section 121 is equal to the grinding allowance of the stub mating section 121. The grinding allowance of the stub mating section 121 is the grinding allowance reserved for the centerless finishing grinding process of the stub mating section 121. That is, d2'-d2 = the grinding allowance of the stub mating section 121. Preferably, the difference between the diameter d2' of the stub oil outlet section 122 and the diameter d2 of the stub oil outlet section 121 is 0.2-0.4 mm. The length L2 of the stub oil outlet section 122 is greater than the diameter f2 of the stub radial oil outlet hole 1221. Preferably, the length L2 of the stub oil outlet section 122 satisfies the following conditions: 1.2f2 ≥ L2 ≥ 1.05f2.

[0045] The crankshaft structure of the embodiment 1, by setting the long shaft oil outlet section and the short shaft oil outlet section, effectively increases the root strength of the long shaft part near the eccentric part and the root strength of the short shaft part near the eccentric part, improves the bending, torsional strength and rigidity of the crankshaft, and further avoids the occurrence of the sweep bore failure in the process of compressor starting and frequency increasing operation.

[0046] Embodiment 2

[0047] The embodiment 2 provides a pump body assembly, which comprises a crankshaft 1, an upper cover 2, a lower cover 3, a cylinder 4, a piston 5, a sliding vane 6 and a spring 7; the upper cover 2 is sealingly arranged on the upper end face of the cylinder 4, and the lower cover 3 is sealingly arranged on the lower end face of the cylinder 4; wherein the upper cover 2 and the cylinder 4 are connected by screw fastening, and the lower cover 3 and the cylinder 4 are also connected by screw fastening; the crankshaft 1 is concentrically assembled in the working cavity of the cylinder 4; wherein the crankshaft 1 adopts the crankshaft structure in the above-mentioned embodiment 1; the long shaft part 11 of the crankshaft 1 is matched and inserted into the upper cover inner hole 22 of the upper cover 2, the short shaft part 12 of the crankshaft 1 is matched and inserted into the lower cover inner hole 32 of the lower cover 3, the piston 5 is arranged in the working cavity of the cylinder 4 and is sleeved outside the eccentric part 13 of the crankshaft 1; the sliding vane 6 is arranged on the outer surface of the piston 5 under the action of the spring 7, and the sliding vane 6 separates the crescent cavity formed by the working cavity of the cylinder and the outer circle of the piston 5 into an air suction cavity and a compression cavity.

[0048] As shown in the accompanying drawings Figure 6 of the embodiment 2, the upper cover end face 21 of the upper cover 2 is in contact with the upper end face of the cylinder 4 and is tightly connected by a screw; the upper cover inner hole 22 comprises a first upper cover inner hole section 221 and a second upper cover inner hole section 222 which are connected concentrically; wherein the first upper cover inner hole section 221 is arranged away from the side of the upper cover end face 21 of the upper cover 2, and the second upper cover inner hole section 222 is arranged close to the side of the upper cover end face 21 of the upper cover 2.

[0049] The diameter g1 of the first upper cover inner hole section 221 is smaller than the diameter g1' of the second upper cover inner hole section 222, so as to ensure that the refrigerant oil in the central oil hole 14 can smoothly flow out through the long shaft radial oil outlet hole when the compressor is running, thereby effectively lubricating the long shaft matching section 111; preferably, the diameter g1 of the first upper cover inner hole section 221 and the diameter g1' of the second upper cover inner hole section 222 satisfy: g1+0.3mm≤g1'≤g1+1.5mm.

[0050] The diameter g1 of the first upper cover inner hole section 221 matches the diameter d1 of the long shaft matching section 111, and the diameter g1' of the second upper cover inner hole section 222 matches the diameter d1' of the long shaft oil outlet section 112; the length h1 of the second upper cover inner hole section 222 is greater than the length L1 of the long shaft oil outlet section 112; preferably, the length h1 of the second upper cover inner hole section 222 and the length L1 of the long shaft oil outlet section 112 satisfy the following relationship: 1.1L1≥h1≥L1.

[0051] As attached Figure 7 As shown, in this embodiment 2, the lower cover end face 31 of the lower cover 3 is in contact with the lower end face of the cylinder 4 and is tightly connected by screws; the lower cover inner hole 32 includes a first lower cover inner hole section 321 and a second lower cover inner hole section 322 which are concentrically connected; wherein, the first lower cover inner hole section 321 is arranged away from the side of the lower cover end face 31 of the lower cover 3, and the second lower cover inner hole section 322 is arranged close to the side of the lower cover end face 31 of the lower cover 3.

[0052] The diameter g2 of the first lower cover inner hole section 321 is smaller than the diameter g2' of the second lower cover inner hole section 322, ensuring that when the compressor is running, the refrigeration oil in the central oil hole 14 can flow out smoothly through the short shaft radial oil outlet hole, thereby effectively lubricating the short shaft mating section 121; preferably, the diameter g2 of the first lower cover inner hole section 321 and the diameter g2' of the second lower cover inner hole section 322 satisfy: g2+0.3mm≤g2'≤g2+1.5mm.

[0053] The diameter g2 of the first lower cover inner hole section 321 matches the diameter d2 of the short shaft matching section 121, and the diameter g2' of the second lower cover inner hole section 322 matches the diameter d2' of the short shaft oil outlet section 122; the length h2 of the second lower cover inner hole section 322 is greater than the length L2 of the short shaft oil outlet section 122; preferably, the length h2 of the second lower cover inner hole section 322 and the length L2 of the short shaft oil outlet section 122 satisfy the following relationship: 1.1L2≥h2≥L2.

[0054] Example 3

[0055] As attached Figure 8 As shown, this embodiment 3 provides a compressor, including a shell 10 and a motor assembly and a pump body assembly arranged in the shell 10; wherein, the motor assembly includes a motor rotor 8 and a motor stator 9; the motor stator 9 is assembled at one end inside the shell 10, and the motor rotor 8 is concentrically assembled in the motor stator 9; the pump body assembly adopts the pump body assembly described in Example 2, which will not be described in detail here.

[0056] It needs to be explained that the extension end of the long shaft part 11 is connected with the motor rotor 8 through hot jacket; the outer circle of the upper cover 2 is connected with the shell 10 through welding and forms support; when the compressor operates, the crankshaft 1 drives the piston 5 to rotate eccentrically under the drive of the motor rotor 8, realizes the suction and compression of gas, and forms the power of the variable frequency rolling rotor type compressor.

[0057] In the application, the long shaft part of the crankshaft is designed in two parts, which are the long shaft matching section 111 in contact with the inner hole of the upper cover and the long shaft oil outlet section 112 for providing lubrication for the long shaft matching section; the short shaft part of the crankshaft is designed in two parts, which are the short shaft matching section 121 in contact with the inner hole of the lower cover and the short shaft oil outlet section 122 for providing lubrication for the short shaft matching section; the long shaft oil outlet section 112 is provided with a long shaft radial oil outlet hole, and the short shaft oil outlet section 122 is provided with a short shaft radial oil outlet hole; one end of the oil outlet hole communicates with the surface of the long shaft or short shaft oil outlet section, and the other end extends radially to the shaft center and penetrates the central oil hole 14 of the crankshaft.

[0058] The crankshaft structure, pump body assembly and compressor provided by the application set the long shaft oil outlet section at the position close to the eccentric part of the long shaft part, and design the diameter of the long shaft oil outlet section to be larger than that of the long shaft matching section; set the short shaft oil outlet section at the position close to the eccentric part of the short shaft part, and design the diameter of the short shaft oil outlet section to be larger than that of the short shaft matching section, which can effectively increase the root strength of the long shaft part and the short shaft part close to the eccentric part of the crankshaft, improve the rigidity of the crankshaft, avoid the root deformation caused by the increase of the operating inertia force and inertia moment of the compressor during the starting and frequency increasing operation of the compressor, and further avoid the occurrence of the sweep bore failure; at the same time, the noise of the compressor is greatly reduced, and the working performance and reliability of the compressor are ensured.

[0059] The above embodiment is only one of the implementation manners of the technical scheme of the application, and the scope of protection of the application is not limited to the embodiment, but also includes any changes, substitutions and other implementation manners easily thought by those skilled in the art within the technical range disclosed by the application.

Claims

1. A crankshaft structure, wherein a central oil hole (14) is provided at the center of the crankshaft structure, characterized in that: It comprises a long axis portion (11), an eccentric portion (13) and a short axis portion (12) which are connected in sequence in the axial direction; The long shaft portion (11) comprises a coaxially arranged long shaft mating section (111) and a long shaft oil outlet section (112); wherein the long shaft oil outlet section (112) is arranged close to one end of the eccentric portion (13), and the diameter of the long shaft oil outlet section (112) is larger than the diameter of the long shaft mating section (111); a long shaft radial oil outlet hole (1121) is provided on the long shaft oil outlet section (112), and the long shaft radial oil outlet hole (1121) is used to connect the surface of the long shaft oil outlet section (112) with the central oil hole (14); The short shaft portion (12) comprises a coaxially arranged short shaft matching section (121) and a short shaft oil outlet section (122); wherein the short shaft oil outlet section (122) is arranged close to one end of the eccentric portion (13), and the diameter of the short shaft oil outlet section (122) is larger than the diameter of the short shaft matching section (121); a short shaft radial oil outlet hole (1221) is provided on the short shaft oil outlet section (122), and the short shaft radial oil outlet hole (1221) is used to connect the surface of the short shaft oil outlet section (122) with the central oil hole (14); The length dimension of the long shaft oil outlet section (112) satisfies the following conditions: 1.2f1≥L1≥1.05f1; wherein L1 is the length of the long shaft oil outlet section (112), and f1 is the diameter of the long shaft radial oil outlet hole (1121); The length dimension of the short shaft oil outlet section (122) satisfies the following: 1.2f2≥L2≥1.05f2; wherein L2 is the length of the short shaft oil outlet section (122), and f2 is the diameter of the short shaft radial oil outlet hole (1221).

2. A crankshaft structure according to claim 1, characterized in that: The surface of the long shaft fitting section (111) is a finely machined surface, and the surface of the long shaft oil outlet section (112) is a rough machined surface; The difference between the diameter of the long shaft oil outlet section (112) and the diameter of the long shaft mating section (111) is the same as the grinding allowance of the long shaft mating section (111); wherein the grinding allowance of the long shaft mating section (111) is the grinding allowance reserved for the centerless grinding process of the long shaft mating section (111).

3. The crankshaft structure according to claim 1, characterized in that: The surface of the short shaft fitting section (121) is a finely machined surface, and the surface of the short shaft oil outlet section (122) is a rough machined surface; The difference between the diameter of the short shaft oil outlet section (122) and the diameter of the short shaft mating section (121) is the same as the grinding allowance of the short shaft mating section (121); wherein the grinding allowance of the short shaft mating section (121) is the grinding allowance reserved for the centerless grinding process of the short shaft mating section (121).

4. A pump assembly, characterized in that: It comprises a crankshaft (1), an upper cover (2), a lower cover (3), a cylinder (4) and a piston (5); the crankshaft (1) adopts a crankshaft structure as described in any one of claims 1 to 3; The upper cover (2) is sealingly arranged on the upper end surface of the cylinder (4), and the lower cover (3) is sealingly arranged on the lower end surface of the cylinder (4); the crankshaft (1) is concentrically assembled in the working chamber of the cylinder (4); The long axis portion (11) of the crankshaft (1) is inserted into the upper cover inner hole (22) of the upper cover (2), and the short axis portion (12) of the crankshaft (1) is inserted into the lower cover inner hole (32) of the lower cover (3); the piston (5) is arranged in the working chamber of the cylinder (4) and is sleeved on the outside of the eccentric portion (13) of the crankshaft (1).

5. A pump assembly according to claim 4, characterized in that: The upper cover inner hole (22) comprises a first upper cover inner hole section (221) and a second upper cover inner hole section (222) which are concentrically connected; wherein the first upper cover inner hole section (221) is arranged on a side away from the upper cover end surface (21) of the upper cover (2), and the second upper cover inner hole section (222) is arranged on a side close to the upper cover end surface (21) of the upper cover (2); The diameter of the first upper cover inner hole section (221) is smaller than the diameter of the second upper cover inner hole section (222); the diameter of the first upper cover inner hole section (221) matches the diameter of the long shaft matching section (111), and the diameter of the second upper cover inner hole section (222) matches the diameter of the long shaft oil outlet section (112); and the length of the second upper cover inner hole section (222) is greater than the length of the long shaft oil outlet section (112).

6. A pump assembly according to claim 4, characterized in that: The lower cover inner hole (32) comprises a first lower cover inner hole section (321) and a second lower cover inner hole section (322) which are concentrically connected; wherein the first lower cover inner hole section (321) is arranged away from the lower cover end surface (31) of the lower cover (3), and the second lower cover inner hole section (322) is arranged close to the lower cover end surface (31) of the lower cover (3); The diameter of the first lower cover inner hole section (321) is smaller than the diameter of the second lower cover inner hole section (322); the diameter of the first lower cover inner hole section (321) matches the diameter of the short shaft matching section (121); the diameter of the second lower cover inner hole section (322) matches the diameter of the short shaft oil outlet section (122); and the length of the second lower cover inner hole section (322) is greater than the length of the short shaft oil outlet section (122).

7. A compressor, characterized in that: The invention comprises a pump body assembly as described in any one of claims 4 to 6.

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