Split crankshaft

Abstract

The utility model relates to a kind of split type crankshafts, including intermediate connecting shaft, and intermediate connecting shaft both sides are connected with primary crankshaft and secondary crankshaft respectively by positioning key and fastening bolt;Primary crankshaft middle part is primary dynamic balance counterweight, and primary dynamic balance counterweight both sides are primary main shaft journal and primary eccentric crankshaft journal respectively, and primary eccentric crankshaft journal is equipped with primary taper hole, and primary taper hole inner wall is equipped with primary key groove, and primary dynamic balance counterweight is equipped with primary screw hole, and primary screw hole is coaxial with primary taper hole and is arranged in communication;Secondary crankshaft middle part is secondary dynamic balance counterweight.The utility model split type crankshaft each section is connected with the corresponding crank connecting rod mechanism, means that each stage in multistage compression is independently formed a module, when meeting primary crank connecting rod mechanism needs to be replaced, without having to take down crankshaft as a whole, can be targeted to take down one section and replace, improve the efficiency of maintenance replacement.

Description

Technical Field

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

[0002] A reciprocating air compressor is a positive displacement compressor that compresses and supplies gas through the reciprocating motion of a piston. Due to its advantages such as a wide applicable pressure range, high compression efficiency, and the ability to handle a variety of gas media, it is widely used in vehicle applications such as door opening and closing, suspension adjustment, braking, and air conditioning systems. The crankshaft drive system is the core structure of a reciprocating air compressor, responsible for converting the rotational motion of the drive motor into the reciprocating motion of the piston assembly. The crankshaft typically has a main shaft journal, an eccentric crankshaft journal, and a keyway, and is connected to the motor main shaft via a coupling and key. It is mounted in the crankcase via a main shaft bearing and connected to the crankshaft and connecting rod mechanism via crankshaft bearings. Currently, most reciprocating air compressors use a one-piece crankshaft, where each stage of the piston and crank assembly is connected to the crankshaft as a single unit. If a component in one stage fails, or if a section of the crankshaft becomes damaged after long-term operation, targeted disassembly and replacement are not possible. Instead, the entire crankshaft, including the piston and connecting rod assembly, must be removed, significantly increasing subsequent maintenance costs. In addition, the entire crankshaft is machined as a single piece, which requires high precision. If any critical dimension is out of tolerance, the entire shaft will be scrapped, which can easily lead to a high scrap rate and increase manufacturing costs. Summary of the Invention

[0003] The purpose of this invention is to provide a split crankshaft that can solve the above-mentioned problems and improve the efficiency of maintenance and replacement.

[0004] According to the technical solution provided by this utility model: a split crankshaft includes an intermediate connecting shaft, on both sides of which a primary crankshaft and a secondary crankshaft are respectively connected by positioning keys and fastening bolts; the primary crankshaft has a primary dynamic balancing counterweight in the middle, with a primary main shaft journal and a primary eccentric crank journal on both sides of the primary dynamic balancing counterweight, the primary eccentric crank journal having a primary tapered hole, the inner wall of the primary tapered hole having a primary keyway, and the primary dynamic balancing counterweight having a primary screw hole, the primary screw hole communicating with and coaxially arranged with the primary tapered hole; the secondary crankshaft has a secondary dynamic balancing counterweight in the middle, with a secondary main shaft journal and a secondary eccentric crank journal on both sides of the secondary dynamic balancing counterweight, the secondary eccentric crank journal having a secondary tapered hole, the inner wall of the secondary tapered hole having a secondary keyway, the secondary main shaft journal having a driven keyway, and the secondary dynamic balancing counterweight having a secondary screw hole, the secondary screw hole communicating with and coaxially arranged with the secondary tapered hole; The central connecting shaft has a central journal in the middle, and the first dynamic balancing counterweight and the second dynamic balancing counterweight are located on both sides of the central journal. The outer side of the first dynamic balancing counterweight is a first-stage crankshaft mating cone, with a first fastening screw mounting hole in the middle and a first keyway on the first-stage crankshaft mating cone. The outer side of the second dynamic balancing counterweight is a second-stage crankshaft mating cone, with a second fastening screw mounting hole in the middle and a second keyway on the second-stage crankshaft mating cone.

[0005] As a further improvement of this utility model, the first-stage crankshaft mating cone is located in the first-stage cone hole; the first positioning key is located in the first-stage keyway and the first keyway.

[0006] As a further improvement of this utility model, the primary crankshaft and the intermediate connecting shaft are axially fixed by the first fastening screw. The first fastening screw passes through the first fastening screw mounting hole and is screwed into the primary screw hole. The head of the first fastening screw is pressed tightly against the inner side of the first dynamic balance counterweight.

[0007] As a further improvement of this utility model, the second dynamic balancing counterweight is provided with a first clearance hole.

[0008] As a further improvement of this utility model, the secondary crankshaft mating cone is located in the secondary cone hole; the second positioning key is located in the secondary keyway and the second keyway.

[0009] As a further improvement of this utility model, the secondary crankshaft and the intermediate connecting shaft are axially fixed by the second fastening screw. The second fastening screw passes through the second fastening screw mounting hole and is screwed into the secondary screw hole. The head of the second fastening screw is pressed tightly against the inner side of the second dynamic balance counterweight.

[0010] As a further improvement of this utility model, the first dynamic balancing counterweight is provided with a second clearance hole.

[0011] The positive and progressive effects of this application are as follows: 1. The modular crankshaft of this utility model is connected to the corresponding crank-connecting rod mechanism in each section. This means that each stage of the multi-stage compression is a separate module. If a certain stage of the crank-connecting rod mechanism needs to be replaced, it is not necessary to remove the entire crankshaft. Instead, a section can be removed and replaced, which improves the efficiency of maintenance and replacement.

[0012] 2. If a section of the split crankshaft is damaged or fails after long-term operation, this utility model allows for targeted replacement of that section, reducing the cost of later crankshaft maintenance.

[0013] 3. The split crankshaft of this utility model improves the situation where the entire crankshaft is scrapped due to out-of-tolerance of some key dimensions during the processing of the one-piece crankshaft, thereby reducing the manufacturing cost. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of the present invention.

[0015] Figure 2 This is a schematic diagram of the structure of the first-stage crankshaft of this utility model.

[0016] Figure 3 This is a schematic diagram of the structure of the two-stage crankshaft of this utility model.

[0017] Figure 4 This is a schematic diagram of the structure of the intermediate connecting shaft of this utility model.

[0018] Figure 5 This is a schematic diagram of the installation structure of this utility model.

[0019] Figure 6 This is a schematic diagram of the structure for installing a positioning key on the intermediate connecting shaft of this utility model.

[0020] Figure 7 This is a schematic diagram of the assembly of this utility model. Detailed Implementation

[0021] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] 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. Obviously, the described embodiments are only 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.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this utility model described herein. Furthermore, terms such as "comprising" and "having" mean that in addition to those already listed in "comprising" and "having," other unlisted contents may also be included; for example, a process, method, system, product, or device may include a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0024] Due to the angle of the drawing, some parts may not be drawn, but their positions and connections can be understood from the text descriptions.

[0025] like Figure 1 As shown, this utility model is a split crankshaft, including an intermediate connecting shaft 2, on both sides of which a primary crankshaft 1 and a secondary crankshaft 3 are respectively connected by positioning keys and fastening bolts.

[0026] like Figure 2 As shown, the first-stage crankshaft 1 has a first-stage dynamic balancing counterweight 12 in the middle. The first-stage dynamic balancing counterweight 12 has a first-stage main shaft journal 8 and a first-stage eccentric crank journal 9 on both sides. The first-stage eccentric crank journal 9 has a first-stage tapered hole 11. The inner wall of the first-stage tapered hole 11 has a first-stage keyway 10. The first-stage dynamic balancing counterweight 12 has a first-stage screw hole. The first-stage screw hole is connected to the first-stage tapered hole 11 and is coaxially arranged.

[0027] like Figure 3 As shown, the middle part of the secondary crankshaft 3 is the secondary dynamic balancing counterweight 18. The two sides of the secondary dynamic balancing counterweight 18 are the secondary main shaft journal 13 and the secondary eccentric crank journal 14, respectively. The secondary eccentric crank journal 14 is provided with a secondary tapered hole 17. The inner wall of the secondary tapered hole 17 is provided with a secondary keyway 16. The secondary main shaft journal 13 is provided with a driven keyway 15. The secondary dynamic balancing counterweight 18 is provided with a secondary screw hole. The secondary screw hole is connected to the secondary tapered hole 17 and is coaxially arranged.

[0028] like Figure 4As shown, the middle connecting shaft 2 has a central journal 27 in the middle, and the two sides of the central journal 27 are a first dynamic balancing counterweight 23 and a second dynamic balancing counterweight 24, respectively. The outer side of the first dynamic balancing counterweight 23 is a first-stage crankshaft mating cone 19, which has a first fastening screw mounting hole 25 in the middle and a first keyway 21 on the first-stage crankshaft mating cone 19. The outer side of the second dynamic balancing counterweight 24 is a second-stage crankshaft mating cone 20, which has a second fastening screw mounting hole 26 in the middle and a second keyway 22 on the second-stage crankshaft mating cone 20.

[0029] The first-stage crankshaft 1 has a first-stage tapered bore 11 that mates with the first-stage crankshaft mating cone 19 of the intermediate connecting shaft 2. The first-stage crankshaft mating cone 19 is located within the first-stage tapered bore 11. The first locating key 4 is located in the first-stage keyway 10 and the first keyway 21, achieving circumferential positioning of the first-stage crankshaft mating cone 19 and the first-stage tapered bore 11. The first-stage crankshaft 1 and the intermediate connecting shaft 2 are axially fixed by a first fastening screw 6. The first fastening screw 6 passes through the first fastening screw mounting hole 25 and is screwed into the first-stage screw hole. The head of the first fastening screw 6 is pressed tightly against the inner side of the first dynamic balancing counterweight 23. To facilitate the connection of the first fastening screw 6, the second dynamic balancing counterweight 24 is provided with a first clearance hole 28.

[0030] The secondary-stage crankshaft 3 has a secondary-stage tapered bore 17 that mates with the secondary-stage crankshaft mating cone 20 of the intermediate connecting shaft 2. The secondary-stage crankshaft mating cone 20 is located within the secondary-stage tapered bore 17. The second locating key 5 is located in the secondary-stage keyway 16 and the second keyway 22, achieving circumferential positioning of the secondary-stage crankshaft mating cone 20 and the secondary-stage tapered bore 17. The secondary-stage crankshaft 3 and the intermediate connecting shaft 2 are axially fixed by a second fastening screw 7. The second fastening screw 7 passes through the second fastening screw mounting hole 26 and is screwed into the secondary-stage screw hole, with the head of the second fastening screw 7 pressing tightly against the inner side of the second dynamic balancing counterweight 24. To facilitate the connection of the second fastening screw 7, the first dynamic balancing counterweight 23 is provided with a second clearance hole 29.

[0031] The primary crankshaft 1, intermediate connecting shaft 2, and secondary crankshaft 3 all have dynamic balancing weights installed to balance the center of gravity of the shafts. The primary crankshaft 1 has a primary dynamic balancing weight 12, the secondary crankshaft 3 has a secondary dynamic balancing weight 18, and the intermediate connecting shaft has a first dynamic balancing weight 23 and a second dynamic balancing weight 24. If a single split shaft or an assembled rotor has its principal axis of inertia deviating from the rotation center axis, dynamic balancing can be performed on the balancing weights to eliminate rotor vibration and extend rotor life. The rotation center axis of the intermediate connecting shaft 2 is located at the axis of the central journal 27.

[0032] like Figure 5As shown, a split crankshaft mounting structure includes a crankshaft chamber, which is composed of a crankcase 34 and a rear cover 35. A primary main bearing 32 and a secondary main bearing 33 are respectively installed on both sides of the crankshaft chamber. The primary main bearing 32 is connected to the primary assembly. The primary assembly consists of a primary crankshaft 1, a primary crank 30, and a primary crank bearing 28. The primary crank bearing 28 is mounted on the primary crank 30 and is interference-fitted with the primary eccentric crank journal 9 of the primary crankshaft 1. The primary main journal 8 of the primary crankshaft 1 is interference-fitted with the primary main bearing 32. The secondary spindle bearing 33 is connected to the secondary assembly; the secondary assembly consists of a secondary crankshaft 3, a secondary crank 31, and a secondary crank bearing 29. The secondary crank 31 is equipped with the secondary crank bearing 29, and the secondary crank bearing 29 is interference-fitted with the secondary eccentric crank journal 14 of the secondary crankshaft 3; the secondary spindle journal 13 of the secondary crankshaft 3 is interference-fitted with the secondary spindle bearing 33.

[0033] like Figure 7 As shown, this illustrates the effect of assembling each component individually. The secondary main shaft journal 13 on the secondary crankshaft 2 also serves as the driven end of the coupling, with a driven keyway 15. It can be connected to the motor main shaft via the coupling, and the motor power source drives the split crankshaft to rotate, causing the crankshaft connecting rod mechanism to reciprocate and achieve a periodic working cycle of intake-compression-exhaust. The specific installation sequence is as follows: First, assemble the secondary components. The outer ring of the secondary main shaft bearing 33 and the bearing hole of the crankcase 34 are interference-fitted. By pressing the secondary main shaft bearing 33 into place, the entire secondary component is installed into the main engine cavity. Next is the installation of the intermediate connecting shaft 2. The first locating key 4 and the second locating key 5 are interference-fitted into the first keyway 21 and the second keyway 22 of the intermediate connecting shaft 2, respectively. The first fastening screw 6 and the second fastening screw 7 are pre-fitted into the first fastening screw mounting holes 25 and 26 of the intermediate connecting shaft 2, as shown. Figure 6As shown. Insert the secondary crankshaft mating cone 20 of the intermediate connecting shaft 2 into the secondary cone hole 17 of the secondary crankshaft. When the second locating key 5 abuts against the locating surface of the secondary keyway 16, tighten the second fastening screw 7 to connect the intermediate connecting shaft 2 and the second crankshaft 3. Finally, install the first crankshaft 1. After the first assembly is in place, insert the entire first-stage assembly into the crankshaft housing 34 through the opening above. The intermediate connecting shaft 2 and the secondary crankshaft 3 can be rotated to ensure sufficient space for the first-stage assembly to pass through. After the first-stage assembly is completely inserted into the crankshaft housing, insert the primary crankshaft mating cone 19 of the intermediate connecting shaft 2 into the primary cone hole 11 of the first-stage crankshaft. When the first locating key 4 abuts against the locating surface of the first keyway 21, tighten the first fastening screw 6 to connect the intermediate connecting shaft 2 and the first crankshaft 1. After the individual crankshaft sections are assembled into a whole, the rear cover 35 is installed onto the crankcase 34. The rear cover 35 has a bearing chamber, and its bearing hole is clearance-fitted with the first main shaft bearing 32 to provide support for the shaft system. At this point, the installation of the individual crankshaft sections is complete. If it is necessary to remove the primary components, intermediate connecting shaft, or secondary components, simply follow the reverse order of installation to complete the disassembly.

[0034] After a split crankshaft has been in operation for a period of time, if any parts in the primary assembly need to be replaced, only the primary assembly needs to be disassembled. If the intermediate connecting shaft and secondary assembly are found to be without problems, they can remain in place. When a new part is needed, the primary assembly in stock can be used for immediate replacement of the entire unit, significantly faster than troubleshooting each part individually, greatly reducing equipment downtime. Similarly, when the intermediate connecting shaft needs replacement, the secondary assembly can remain in place, requiring only the replacement of the primary assembly and intermediate connecting shaft. Even if replacing a secondary assembly necessitates the complete disassembly of all components of the split crankshaft, the split design allows for pre-assembly of each stage of the crankshaft and connecting rod mechanism with the matching split shaft. During actual installation and maintenance, the entire assembly can be installed and disassembled on the crankshaft, effectively shortening the equipment maintenance cycle.

[0035] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this utility model, and the utility model is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of this utility model, and these modifications and improvements are also considered to be within the protection scope of this utility model.

Claims

1. A split crankshaft, comprising an intermediate connecting shaft (2), wherein a primary crankshaft (1) and a secondary crankshaft (3) are respectively connected to both sides of the intermediate connecting shaft (2) via positioning keys and fastening bolts; characterized in that, The first-stage crankshaft (1) has a first-stage dynamic balancing counterweight (12) in the middle. The first-stage dynamic balancing counterweight (12) has a first-stage main shaft journal (8) and a first-stage eccentric crank journal (9) on both sides. The first-stage eccentric crank journal (9) has a first-stage tapered hole (11). The inner wall of the first-stage tapered hole (11) has a first-stage keyway (10). The first-stage dynamic balancing counterweight (12) has a first-stage screw hole. The first-stage screw hole is connected to the first-stage tapered hole (11) and is coaxially arranged. The second-stage crankshaft (3) has a second-stage counterweight in the middle. The dynamic balancing counterweight (18) has a secondary main shaft journal (13) and a secondary eccentric crank journal (14) on both sides. The secondary eccentric crank journal (14) is provided with a secondary tapered hole (17). The inner wall of the secondary tapered hole (17) is provided with a secondary keyway (16). The secondary main shaft journal (13) is provided with a driven keyway (15). The secondary dynamic balancing counterweight (18) is provided with a secondary screw hole. The secondary screw hole is connected to the secondary tapered hole (17) and is coaxially arranged. The middle connecting shaft (2) has a central journal (27) in the middle. The central journal (27) has a first dynamic balancing counterweight (23) and a second dynamic balancing counterweight (24) on both sides. The first dynamic balancing counterweight (23) has a first-stage crankshaft mating cone (19) on the outside. The first-stage crankshaft mating cone (19) has a first fastening screw mounting hole (25) in the middle and a first keyway (21) on the first-stage crankshaft mating cone (19). The second dynamic balancing counterweight (24) has a second-stage crankshaft mating cone (20) on the outside. The second-stage crankshaft mating cone (20) has a second fastening screw mounting hole (26) in the middle and a second keyway (22) on the second-stage crankshaft mating cone (20).

2. The split crankshaft as described in claim 1, characterized in that, The first-stage crankshaft mating cone (19) is located in the first-stage cone hole (11); the first positioning key (4) is located in the first-stage keyway (10) and the first keyway (21).

3. The split crankshaft as described in claim 1, characterized in that, The primary crankshaft (1) and the intermediate connecting shaft (2) are axially fixed by the first fastening screw (6). The first fastening screw (6) passes through the first fastening screw mounting hole (25) and is screwed into the primary screw hole. The head of the first fastening screw (6) is pressed tightly against the inner side of the first dynamic balance counterweight (23).

4. The split crankshaft as described in claim 3, characterized in that, The second dynamic balancing counterweight (24) is provided with a first clearance hole (28).

5. The split crankshaft as described in claim 1, characterized in that, The secondary crankshaft mating cone (20) is located in the secondary cone hole (17); the second locating key (5) is located in the secondary keyway (16) and the second keyway (22).

6. The split crankshaft as described in claim 1, characterized in that, The secondary crankshaft (3) and the intermediate connecting shaft (2) are axially fixed by the second fastening screw (7). The second fastening screw (7) passes through the second fastening screw mounting hole (26) and is screwed into the secondary screw hole. The head of the second fastening screw (7) is pressed tightly against the inner side of the second dynamic balance counterweight (24).

7. The split crankshaft as described in claim 6, characterized in that, The first dynamic balancing counterweight (23) is provided with a second clearance hole (29).

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