4-balance block crank structure

Abstract

The utility model discloses a 4 balance block crankshaft structure, including crankshaft body, the crankshaft body includes main shaft neck, connecting rod axle neck, crank, front end axle and rear end axle, is equipped with 3 main shaft necks at least, install the main bearing bush on the main shaft neck, and the clearance of each main shaft neck and main bearing bush is X, and the clearance of the main shaft neck and the intermediate stop main bearing bush of being in the intermediate stop is 0.01~0.02mm than the clearance of other main shaft neck and its main bearing bush is big. The utility model has simple structure, can improve the oil film stability of main shaft neck and main bearing bush, and reduce the advantages such as main shaft neck and main bearing bush wear.

Description

Technical Field

[0001] This utility model relates to the field of engine crankshaft technology, and in particular to a crankshaft structure with 4 balance blocks. Background Technology

[0002] Ideally, crankshafts should have two balancing weights on opposite sides of each connecting rod journal to counteract the centrifugal force generated during rotation. If one end is too heavy, it will become unbalanced at high speeds. However, with increasing demands for crankshaft weight reduction, the number of balancing weights must be reduced. Therefore, a four-balancing-weight crankshaft meets current design requirements. Currently, four-balancing-weight crankshafts suffer from low balance, leading to significant rotational slippage. Poor balance results in a thinner and less stable oil film between the bearing and crankshaft, increasing the risk of bearing failure.

[0003] In addition, during crankshaft movement, due to the downward burst pressure from the combustion gases in the cylinder, the crankshaft will inevitably bend downward to a certain extent. This may cause the edge of the bearing to come into direct contact with the crankshaft journal during the early break-in period, resulting in wear and even seizing and bearing failure.

[0004] Existing patent document CN212337878U discloses a crankshaft and bearing mounting structure, which solves the problem of uneven wear of the main bearing caused by increased engine explosion pressure. This structure has low cost, involves few modified parts, and requires minimal modifications, greatly reducing the development cycle and lowering the cost of material management in the later stages.

[0005] The above background information is provided only to aid in understanding the concept and technical solution of this utility model. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content

[0006] The main purpose of this invention is to propose a simple structure for a crankshaft with four balance blocks that can improve the oil film stability of the main journal and main bearing and reduce the wear of the main journal and main bearing.

[0007] Therefore, this utility model proposes a crankshaft structure with 4 balance blocks.

[0008] Preferably, the present invention may also have the following technical features:

[0009] A four-balance-weight crankshaft structure includes a crankshaft body, which includes main journals, connecting rod journals, cranks, a front shaft, and a rear shaft. At least three main journals are provided, and main bearings are mounted on the main journals. The clearance between each main journal and its main bearing is X. The clearance between the main journal in the middle section and its main bearing in the middle section is 0.01~0.02mm larger than the clearances of the other main journals and their main bearings.

[0010] Furthermore, the diameter of the main journal in the intermediate section is 0.01~0.02mm smaller than that of the other main journals.

[0011] Furthermore, the crankshaft body is mounted on a 4-cylinder engine and has three main journals, including a first main journal, a second main journal, and a third main journal. The second main journal is located in the middle position, and the first and third main journals are located on both sides of the second main journal. The second main journal is the intermediate main journal, and the other main journals are the first and third main journals.

[0012] Furthermore, the inner diameter of the main bearing in the middle section is 0.01~0.02mm larger than that of the other main bearings.

[0013] Furthermore, the crankshaft body is mounted on a 6-cylinder engine and has 5 main journals.

[0014] Furthermore, each main journal gradually bulges from both ends to the middle along the axial direction, resulting in a convex structure in the middle of the main journal.

[0015] Furthermore, the maximum protrusion of the main journal is 0.001-0.007mm.

[0016] Furthermore, the maximum protrusion of the main journal is 0.003-0.005mm.

[0017] The beneficial effects of this invention compared to existing technologies include: by increasing the clearance of the crankshaft intermediate bearing bush, the stability of oil film establishment is improved, thus preventing bearing failure. However, excessive bearing bush clearance also has drawbacks; excessive oil unloading leads to reduced oil pressure, affecting the lubrication of other parts, while the clearance of other bearing bushes remains unchanged. After the modification, the intermediate bearing bush uses an oil film with a clearance increased by 0.01-0.02 mm, while the oil film of other bearing bushes remains the same. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention. Some crankshaft structures cannot be shown due to the cutting angle.

[0019] Figure 2 yes Figure 1 A partial sectional view.

[0020] Figure 3 This is an assembly diagram of the main journal and main bearing of this utility model. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to specific embodiments and the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope and application of the present invention.

[0022] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein the same reference numerals denote the same parts unless otherwise specifically stated.

[0023] like Figures 1-2 The diagram illustrates a four-balance-weight crankshaft structure, fitted to engines with four or more cylinders. It includes a crankshaft body 1, comprising main journals 8, main bearings 9, connecting rod journals 6, cranks 5, a front shaft, and a rear shaft. At least three main journals 5 are provided, and main bearings are mounted on each journal. The clearance between the intermediate main journal 7 and the intermediate main bearing 4 is 0.01~0.02 mm larger than the clearances of the other main journals 2 and their corresponding main bearings 3. For example, normally the clearance between all main journals and main bearings on the crankshaft is X. In this application, to improve oil film establishment stability, as an improvement, the clearance between the intermediate main journal 7 and the intermediate main bearing 4 is increased, making it (X+0.01)~(X+0.02).

[0024] In some embodiments, the diameter of the intermediate main journal 7 is 0.01~0.02mm smaller than the diameters of the other main journals 2, resulting in a larger gap between the intermediate main journal 7 and the intermediate main bearing 4. The other main journals 2 refer to the main journals 2 of the same crankshaft other than the intermediate main journal 7. For example, if there are a first main journal, a second main journal, and a third main journal, and the second main journal is in the middle position, with the first and third main journals located on either side of the second main journal, then the second main journal is the intermediate main journal 7, and the other main journals 2 are the first and third main journals. In this embodiment, by reducing the diameter of the intermediate main journal 7 while maintaining the inner diameter of the intermediate main bearing 4, a larger gap is achieved between the intermediate main journal 7 and the intermediate main bearing 4.

[0025] In other embodiments, the inner diameter of the intermediate bearing 4 is 0.01~0.02mm larger than the inner diameter of the other bearings 3. The other bearings 3 refer to the bearings of the same crankshaft other than the intermediate bearing 4. In this embodiment, by keeping the diameter of the intermediate bearing journal 7 unchanged and increasing the inner diameter of the intermediate bearing 4, the gap between the intermediate bearing journal 7 and the intermediate bearing 4 is made larger.

[0026] In some embodiments, three main journals are provided, and the crankshaft body 1 is mounted on a 4-cylinder engine.

[0027] In other embodiments, five main journals are provided, and the crankshaft body 1 is mounted on a 6-cylinder engine.

[0028] Combination Figure 3 In a preferred embodiment of the above technical solution, all the main journals 8 on the crankshaft body 1 gradually bulge from both ends to the middle in the axial direction, so that the middle part of the main journal 8 has a raised structure 10. This can improve the wear at both ends of the main journal 8 in the axial direction and the edge of the main bearing 9. Preferably, the maximum protrusion of the main journal 8 is 0.001-0.007 mm. More specifically, the maximum protrusion of the main journal is 0.004 mm.

[0029] In a more preferred embodiment, the inner sides of both ends of the bearing bush in the axial direction are chamfered to further reduce wear.

[0030] Those skilled in the art will recognize that numerous variations are possible with respect to the above description, and the embodiments and figures are merely for describing one or more specific implementations.

[0031] Although exemplary embodiments of the present invention have been described and illustrated, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the present invention. Furthermore, many modifications can be made to adapt specific situations to the doctrine of the present invention without departing from the central concept of the present invention described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but may include all embodiments and equivalents that fall within the scope of the present invention.

Claims

1. A four-balance-weight crankshaft structure, comprising a crankshaft body, the crankshaft body including main journals, connecting rod journals, cranks, a front shaft, and a rear shaft, having at least three main journals, with main bearings mounted on the main journals, the clearance between each main journal and the main bearing being X, characterized in that: The clearance between the main journal in the intermediate section and the main bearing in the intermediate section is 0.01~0.02mm larger than the clearance between the other main journals and their bearings.

2. The four-balance-block crankshaft structure as described in claim 1, characterized in that: The diameter of the main journal in the intermediate position is 0.01~0.02mm smaller than that of the other main journals.

3. The four-balance-block crankshaft structure as described in claim 1 or 2, characterized in that: The crankshaft body is mounted on a 4-cylinder engine and has three main journals, including a first main journal, a second main journal, and a third main journal. The second main journal is located in the middle position, and the first and third main journals are located on both sides of the second main journal. The second main journal is the intermediate main journal, and the other main journals are the first and third main journals.

4. The four-balance-block crankshaft structure as described in claim 1, characterized in that: The inner diameter of the main bearing in the middle section is 0.01~0.02mm larger than that of the other main bearings.

5. The four-balance-block crankshaft structure as described in claim 1, characterized in that: The crankshaft body is mounted on a 6-cylinder engine and has 5 main journals.

6. The four-balance-block crankshaft structure as described in claim 1, characterized in that: Each main journal bulges gradually from both ends to the middle along the axial direction, resulting in a convex structure in the middle of the main journal.

7. The four-balance-block crankshaft structure as described in claim 6, characterized in that: The maximum protrusion of the main journal is 0.001-0.007mm.

8. The four-balance-block crankshaft structure as described in claim 7, characterized in that: The maximum protrusion of the main journal is 0.003-0.005mm.

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