Split crankshaft and air compressor

Abstract

The utility model belongs to air compressor equipment technical field relates to a split type crankshaft and air compressor, including first axle body, second axle body, first axle body, second axle body are connected through the shaft coupling assembly, and the shaft coupling assembly includes the shaft coupling driving part, elastic element and the shaft coupling driven part, the shaft coupling driving part is fixedly connected with first axle body, and the shaft coupling driven part is fixedly connected with second axle body, the elastic element is set between the shaft coupling driving part and the shaft coupling driven part, and is engaged with the shaft coupling driving part, the shaft coupling driven part simultaneously, to realize power transmission. The two sections of axle body of this crankshaft adopt the shaft coupling connection, and the elastic element can buffer the vibration and impact in the rotation of crankshaft, reduces the system noise and prolongs the bearing life, and simultaneously the shaft coupling can efficiently, reliably transmit the complex load of crankshaft connecting place, reduces the stress level of bolt, makes it concentrate on providing stable clamping force.

Description

Technical Field

[0001] This utility model belongs to the technical field of air compressor equipment, and relates to a split crankshaft and air compressor. Background Technology

[0002] The crankshaft is one of the most critical components of an air compressor. It converts the rotational motion of the drive source into the reciprocating linear motion of the piston through a crank-connecting rod structure, thereby compressing the gas.

[0003] The crankshaft structure mainly includes the main journal, connecting rod journal, and balance weight. The working principle of the crankshaft structure is as follows: During operation, the motor drives the crankshaft to rotate, and the connecting rod journal rotates in a circle around the central axis of the main journal, simultaneously driving the big end of the connecting rod connected to the connecting rod journal to rotate at the same speed. The small end of the connecting rod is connected to the piston via a piston pin. Because the connecting rod is a rigid rod, when the big end of the connecting rod rotates with the crankshaft, the small end of the connecting rod (along with the piston) is forced to perform reciprocating linear motion within the cylinder.

[0004] Problems with existing crankshaft structures: Traditional integral long crankshafts are difficult to manufacture and have concentrated torsional vibrations. Single-point failures can easily lead to the scrapping of the entire shaft, resulting in high maintenance costs. Existing split crankshafts generally use rigid flanges or locating pins for connection. Under alternating loads (rotational bending and torsional loads on the crankshaft), this method is prone to fatigue fracture at the connection, leading to crankshaft failure. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a split crankshaft, in which the two sections of the crankshaft are connected by a coupling. The elastic element can buffer the vibration and impact during crankshaft rotation, reduce system noise, and extend bearing life. At the same time, the coupling can efficiently and reliably transmit the complex load at the crankshaft connection, reduce the stress level of the bolts, and allow them to focus on providing stable clamping force.

[0006] According to the technical solution of this utility model: a split crankshaft, including a first shaft and a second shaft, characterized in that: the first shaft and the second shaft are connected by a coupling assembly, the coupling assembly including a coupling driving part, an elastic element and a coupling driven part; The driving part of the coupling is fixedly connected to the first shaft, and the driven part of the coupling is fixedly connected to the second shaft; The elastic element is disposed between the driving part and the driven part of the coupling, and simultaneously meshes with both the driving part and the driven part of the coupling to achieve power transmission.

[0007] As a further improvement of this utility model, the end face of the first shaft output end is constructed with an integrally connected first sector-shaped balance block, and the end face of the first sector-shaped balance block is constructed with an integrally connected first crankshaft journal. The first eccentric shaft is integrally connected to the end face structure of the active part of the coupling, and the first eccentric shaft is fixedly connected to the first tapered hole of the first crank journal.

[0008] As a further improvement of this utility model, the circumferential surface of the first eccentric shaft is provided with a first keyway extending along the axial direction, the inner wall of the first tapered hole is provided with a second keyway, the first keyway and the second keyway are connected by a first positioning key, and the first eccentric shaft and the first sector-shaped balance block are fixedly connected by a first fastening bolt.

[0009] As a further improvement of this utility model, the second shaft includes a second main journal, a second sector-shaped balance block, and a second crank journal that are sequentially arranged and integrally connected along the axial direction, and the second crank journal is provided with a second tapered hole; The driven part of the coupling has an integrally connected second eccentric shaft at its end face, and the second eccentric shaft is fixedly connected to the second tapered hole.

[0010] As a further improvement of this utility model, the circumferential surface of the second eccentric shaft is provided with a third keyway, and the inner wall of the second conical hole is provided with a fourth keyway. The third keyway and the fourth keyway are connected by a second positioning key, and the second eccentric shaft and the second sector-shaped balance block are fixedly connected by a second fastening bolt.

[0011] As a further improvement of this utility model, the first crank journal of the first shaft body and the second crank journal of the second shaft body are arranged opposite each other at 180°.

[0012] As a further improvement of this utility model, the elastic element is a plum blossom-shaped polyurethane elastic element, and protrusions are evenly distributed on both sides of the elastic element. The protrusions on both sides abut against the bottom surfaces of the driving part and the driven part of the coupling, respectively. The driving part of the coupling has several driving end claw surfaces evenly distributed along the circumferential direction on the side surface opposite to the first eccentric shaft, and the driven part of the coupling has several driven end claw surfaces evenly distributed along the circumferential direction on the side surface opposite to the second eccentric shaft. The driving end claw surfaces and driven end claw surfaces are respectively pressed into the corresponding tooth grooves of the elastic element.

[0013] As a further improvement of this utility model, the rotation center of the active part of the coupling is provided with a through-hole at the active end, the rotation center of the elastic element is provided with a through-hole in the shape of a plum blossom, and the rotation center of the driven part of the coupling is provided with a through-hole at the driven end.

[0014] This application also provides an air compressor characterized by including the aforementioned split crankshaft.

[0015] The technical advantages of this invention are as follows: Since the split crankshaft is connected by a coupling, its elastic element can buffer the vibration and impact during crankshaft rotation, reduce system noise and extend bearing life; at the same time, the coupling can efficiently and reliably transmit the complex load at the crankshaft connection, reduce the stress level of the bolts, and allow them to focus on providing stable clamping force.

[0016] The direct drive design (where the motor spindle is directly connected to the air compressor crankshaft) simplifies the overall structure, reduces manufacturing and material costs, minimizes transmission losses, and improves overall energy efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the structure of the first shaft.

[0019] Figure 3 This is a schematic diagram of the second shaft.

[0020] Figure 4 This is an exploded view of the coupling assembly.

[0021] Figure 5 This is a schematic diagram of an air compressor. Detailed Implementation

[0022] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0024] Figure 1-5The coupling includes a first shaft 1, a first main journal 101, a first sector-shaped balance block 102, a first crank journal 103, a first tapered hole 104, a second keyway 105, a second shaft 2, a second main journal 201, a second sector-shaped balance block 202, a second crank journal 203, a second tapered hole 204, a fourth keyway 205, a coupling drive unit 3, a drive end shaft hole 301, a first eccentric shaft 302, a first keyway 303, a drive end claw surface 304, and an elastic element. 4. Plum blossom through hole 401, upper convex petal surface 402, lower convex petal surface 403, driven part of coupling 5, driven end shaft hole 501, second eccentric shaft 502, third keyway 503, driven end claw surface 504, first positioning key 6, first fastening bolt 7, second positioning key 8, second fastening bolt 9, first main shaft bearing 10, first crank bearing 11, first crank 12, second crank bearing 13, second crank 14, second main shaft bearing 15, crankcase 16, etc.

[0025] like Figure 1-4 As shown, this utility model is a split crankshaft, including a first shaft 1 and a second shaft 2. The first shaft 1 and the second shaft 2 are connected by a coupling assembly, which includes a coupling driving part 3, an elastic element 4 and a coupling driven part 5.

[0026] The driving part 3 of the coupling is fixedly connected to the first shaft 1, and the driven part 5 of the coupling is fixedly connected to the second shaft 2.

[0027] The elastic element 4 is disposed between the driving part 3 and the driven part 5 of the coupling, and simultaneously meshes with both the driving part 3 and the driven part 5 of the coupling to realize power transmission.

[0028] The output end of the first shaft 1 has an integrally connected first sector-shaped balance block 102, and the end face of the first sector-shaped balance block 102 has an integrally connected first crankshaft journal 103.

[0029] The end face of the coupling drive part 3 is integrally connected to the first eccentric shaft 302. The first eccentric shaft 302 and the first tapered hole 104 of the first crank journal 103 form a tapered surface fit and are fixedly connected.

[0030] The circumferential surface of the first eccentric shaft 302 is provided with a first keyway 303 extending along the axial direction, and the inner wall of the first tapered hole 104 is provided with a second keyway 105. The first keyway 303 and the second keyway 105 are connected by a first positioning key 6. The first eccentric shaft 302 and the first sector-shaped balance block 102 are fixedly connected by a first fastening bolt 7.

[0031] The second shaft 2 includes a second main journal 201, a second sector-shaped balance block 202, and a second crank journal 203, which are arranged sequentially along the axial direction and integrally connected. The second crank journal 203 is provided with a second tapered hole 204.

[0032] The driven part 5 of the coupling has an integrally connected second eccentric shaft 502 at its end face, which is fixedly connected to the second tapered hole 204. When the crankshaft rotates, the eccentric part (crankshaft journal) generates centrifugal force. The balance block counteracts these forces through symmetrically distributed mass, preventing the crankshaft from bending and deforming. The axes of the first main journal 101, the driving end 3 of the coupling, the plum blossom-shaped elastic element 4, the driven end 5 of the coupling, and the second main journal 201 are coaxial, effectively reducing the rotational torque.

[0033] The circumferential surface of the second eccentric shaft 502 is provided with a third keyway 503, and the inner wall of the second tapered hole 204 is provided with a fourth keyway 205. The third keyway 503 and the fourth keyway 205 are connected by a second positioning key 8. The second eccentric shaft 502 and the second sector-shaped balance block 202 are fixedly connected by a second fastening bolt 9.

[0034] The first crank journal 103 of the first shaft 1 and the second crank journal 203 of the second shaft 2 are positioned 180° opposite each other, that is, with a phase difference of 180°. In this way, the inertial force and inertial torque generated by the crank assembly will cancel each other out, significantly reducing the vibration during machine operation.

[0035] The elastic element 4 is a plum blossom-shaped polyurethane elastic element, and protrusions are evenly distributed on both sides of the elastic element 4. The protrusions on both sides abut against the bottom surfaces of the driving part 3 and the driven part 5 of the coupling, respectively. During operation, when subjected to large torque, the protrusions can provide additional compressive support to prevent the elastic element 4 from being over-compressed.

[0036] On the side of the coupling's driving part 3 opposite to the first eccentric shaft 302, several driving end claw surfaces 304 are evenly distributed circumferentially. On the side of the coupling's driven part 5 opposite to the second eccentric shaft 502, several driven end claw surfaces 504 are evenly distributed circumferentially. The driving end claw surfaces 304 and driven end claw surfaces 504 respectively engage with the corresponding tooth grooves of the elastic element 4. The elastic element 4 has elastic deformation, enabling reliable connection with the coupling's driving part 3 and driven part 5, and reliable absorption of vibration and deviation during operation. The driving end claw surface 304 meshes with the upper convex petal surface 402 of the elastic element 4, and the lower convex petal surface 403 of the elastic element 4 meshes with the driven end claw surface 504. That is, the petal portion is embedded between the claws of the two halves of the coupling, transmitting torque through compression deformation. The elastic deformation of elastic element 4 can absorb radial, angular, and axial displacements, effectively reducing vibration and impact. The gap between the driving end claw surface 304, the driven end claw surface 504, and the elastic element 4 allows for small-angle deflection (typically ≤1°). The compressibility of elastic element 4 can absorb axial displacement (such as thermal expansion). The elastic deformation of elastic element 4 can absorb instantaneous impacts (such as peak torque during motor startup).

[0037] A through-hole 401 is provided through the rotation center of the elastic element 4. The through-hole 401 effectively reduces material usage, lowers the overall weight of the coupling, and reduces rotational inertia. A drive end shaft hole 301 is provided through the rotation center of the driving part 3 of the coupling, and a driven end shaft hole 501 is provided through the rotation center of the driven part 5 of the coupling. The drive end shaft hole 301 and the driven end shaft hole 501 facilitate alignment during installation and provide heat dissipation and ventilation during high-speed operation. The coaxial arrangement of the through-hole 401, drive end shaft hole 301, and driven end shaft hole 501 avoids the introduction of additional bending moments and vibrations.

[0038] like Figure 5 As shown, this application also provides an air compressor including the aforementioned split crankshaft. The crankshaft's rotation within the housing 16 is achieved using bearings. A first main shaft bearing 10 is interference-fitted with a first main shaft journal 101; a first crankshaft journal 103 is interference-fitted with a first crankshaft bearing 11 on a first crank 12; a second crankshaft journal 203 is interference-fitted with a second crankshaft bearing 13 on a second crank 14; and a second main shaft journal 201 is interference-fitted with a second main shaft bearing 15. The first main shaft bearing 10 and the second main shaft bearing 15 serve as support bearings, through which the split crankshaft is fixed to the inner wall of the air compressor housing.

[0039] This application uses an elastic element 4 to connect the driving part 3 and the driven part 5 of the coupling. The elastic element 4 is located between the driving part 3 and the driven part 5, and is usually made of polyurethane, rubber, or nylon. It has a multi-petaled clover shape and meshes with the claw surfaces of the driving part 3 and the driven part 5. Power transmission is achieved by the protruding claws of the driving part 3 and the driven part 5 pressing against the multi-petaled clover structure of the elastic element 4, driving the second shaft 2 to rotate. The elasticity of the elastic element 4 allows for a certain centerline offset between the first shaft 1 and the second shaft 2 (usually ≤0.5mm).

[0040] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A split crankshaft, comprising a first crankshaft body (1) and a second crankshaft body (2), characterized in that: The first shaft (1) and the second shaft (2) are connected by a coupling assembly, which includes a coupling driving part (3), an elastic element (4) and a coupling driven part (5). The driving part (3) of the coupling is fixedly connected to the first shaft (1), and the driven part (5) of the coupling is fixedly connected to the second shaft (2); The elastic element (4) is disposed between the driving part (3) and the driven part (5) of the coupling, and simultaneously meshes with the driving part (3) and the driven part (5) of the coupling to realize power transmission.

2. The split crankshaft as described in claim 1, characterized in that: The first shaft (1) has an integrally connected first sector-shaped balance block (102) on the end face of the output end, and the first crankshaft journal (103) is integrally connected on the end face of the first sector-shaped balance block (102). The first eccentric shaft (302) is integrally connected to the end face of the coupling active part (3), and the first eccentric shaft (302) is fixedly connected to the first tapered hole (104) of the first crank journal (103).

3. The split crankshaft as described in claim 2, characterized in that: The first eccentric shaft (302) has a first keyway (303) extending axially on its circumferential surface, and a second keyway (105) is provided on the inner wall of the first tapered hole (104). The first keyway (303) and the second keyway (105) are connected by a first positioning key (6), and the first eccentric shaft (302) and the first sector-shaped balance block (102) are fixedly connected by a first fastening bolt (7).

4. The split crankshaft as described in claim 1, characterized in that: The second shaft (2) includes a second main journal (201), a second sector-shaped balance block (202), and a second crank journal (203) that are sequentially arranged and integrally connected along the axial direction. The second crank journal (203) is provided with a second tapered hole (204). The end face of the driven part (5) of the coupling is integrally connected to the second eccentric shaft (502), and the second eccentric shaft (502) is fixedly connected to the second tapered hole (204).

5. The split crankshaft as described in claim 4, characterized in that: The second eccentric shaft (502) has a third keyway (503) on its circumferential surface and a fourth keyway (205) on the inner wall of the second conical hole (204). The third keyway (503) and the fourth keyway (205) are connected by a second positioning key (8). The second eccentric shaft (502) and the second sector-shaped balance block (202) are fixedly connected by a second fastening bolt (9).

6. The split crankshaft as described in claim 1, characterized in that: The first crank journal (103) of the first shaft (1) and the second crank journal (203) of the second shaft (2) are positioned 180° opposite each other.

7. The split crankshaft as described in claim 1, characterized in that: The elastic element (4) is a plum blossom-shaped polyurethane elastic element, and protrusions are evenly distributed on both sides of the elastic element (4). The protrusions on both sides abut against the bottom surfaces of the coupling driving part (3) and the coupling driven part (5). The active part (3) of the coupling has several active end claw surfaces (304) evenly distributed along the circumferential direction on the side surface opposite to the first eccentric shaft (302), and the driven part (5) of the coupling has several driven end claw surfaces (504) evenly distributed along the circumferential direction on the side surface opposite to the second eccentric shaft (502). The active end claw surfaces (304) and driven end claw surfaces (504) are respectively pressed and engaged with the corresponding tooth grooves of the elastic element (4).

8. The split crankshaft as described in claim 1, characterized in that: The rotation center of the active part (3) of the coupling is provided with a through-hole (301), the rotation center of the elastic element (4) is provided with a through-hole (401), and the rotation center of the driven part (5) of the coupling is provided with a through-hole (501).

9. An air compressor, characterized in that: Including the split crankshaft as described in any one of claims 1-7.

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