Low-friction light-weight engine crankshaft structure

Abstract

The utility model relates to the technical field of crankshafts, in particular to a low-friction light-weight engine crankshaft structure which comprises a front end shaft, a front balance block, a connecting rod journal, a rear balance block and a rear end shaft which are sequentially arranged, the connecting rod journal is of a tubular structure, and the front balance block and the rear balance block are both connected with the connecting rod journal in an inserted mode. The crankshaft further comprises a plurality of interior angle screws, the connecting rod journal is fixed to the front balance block and the rear balance block through the interior angle screws, the structure of the crankshaft can be simplified, and the assembling efficiency of the crankshaft is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of crankshafts, and specifically relates to a low-friction and lightweight engine crankshaft structure. Background Art

[0002] The crankshaft is an important mechanical part, commonly found in engines. Its main function is to convert reciprocating motion into rotational motion, thereby providing power output. The crankshaft is usually cast or forged from high-strength alloy steel. It has multiple connection points for connecting rods, and these connecting rods are connected to pistons. When the piston reciprocates in the cylinder, through the connection between the connecting rod and the crankshaft, the crankshaft will convert the reciprocating motion of the piston into the rotational motion of the crankshaft itself. The mass of the crankshaft accounts for about 10% of the total engine mass, and its size and weight largely determine and affect the overall size and weight of the internal combustion engine. Therefore, applying effective weight reduction measures to the crankshaft will be beneficial to improving the fuel consumption of the entire engine and reducing costs.

[0003] In the prior art, for example, in a lightweight crankshaft structure of a diesel engine in a Chinese patent with the publication number CN221647394U, by arranging a connecting rod journal with a pentagonal prism between two balance weights, and the connection between the balance weight and the connecting rod journal is realized by a central bolt, a reinforcing ring, and a reinforcing plate. The disadvantage of this crankshaft is that the structure is too complex, which brings trouble to assembly. Content of the Utility Model

[0004] Aiming at the deficiencies existing in the prior art, the purpose of the utility model is to provide a low-friction and lightweight engine crankshaft structure, which can simplify the structure of the crankshaft and improve the assembly efficiency of the crankshaft.

[0005] To achieve the above purpose, the utility model provides the following technical solution: A low-friction and lightweight engine crankshaft structure includes a front end shaft, a front balance weight, a connecting rod journal, a rear balance weight, and a rear end shaft arranged in sequence. Among them, the connecting rod journal is a tubular structure, and both the front balance weight and the rear balance weight are inserted into the connecting rod journal; the crankshaft also includes several internal angle screws, and the connecting rod journal is fixed to the front balance weight and the rear balance weight through the internal angle screws.

[0006] Preferably, the connecting rod journal is composed of a front connecting shaft, a connecting rod journal body, and a rear connecting shaft arranged in sequence; through holes are respectively opened at the tops of the front balance weight and the rear balance weight along the direction parallel to the axis of the front end shaft; the front connecting shaft penetrates through the through hole of the front balance weight, and the rear connecting shaft penetrates through the through hole of the rear balance weight; the connecting rod journal body is located between the front balance weight and the rear balance weight.

[0007] Preferably, the outer diameter of the connecting rod journal body is greater than the outer diameters of the front connecting shaft and the rear connecting shaft.

[0008] Preferably, both between the front connecting shaft and the front balance weight and between the rear connecting shaft and the rear balance weight are fixedly connected by internal angle screws.

[0009] Preferably, an upper screw hole communicating with the through hole is provided at the top of the front balance weight; the internal angle screw passes through the upper screw hole and is threadedly connected to the front connecting shaft.

[0010] Preferably, the axis of the internal angle screw is perpendicular to the axis of the front connecting shaft.

[0011] Preferably, key grooves are provided on the inner wall of the through holes of both the front balance weight and the rear balance weight; keys mating with the key grooves at corresponding positions are provided on the outer circumferences of the front connecting shaft and the rear connecting shaft.

[0012] Preferably, inclined weight-reducing cut surfaces are provided on the outer sides of the tops of both the front balance weight and the rear balance weight.

[0013] Preferably, the outer end surface of the key is flush with the inclined weight-reducing cut surface at the corresponding position.

[0014] Preferably, the connecting rod journal is in a tight fit with both the front balance weight and the rear balance weight.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows: By providing a connecting rod journal between the front balance weight and the rear balance weight, the connecting rod journal is inserted into both the front balance weight and the rear balance weight, and at the same time, the connecting rod journal is fixedly connected to the front balance weight and the rear balance weight by internal angle screws. The connecting rod journal is of a tubular structure. With such a design, the structure of the crankshaft is simple and easy to assemble, which is beneficial to improving the assembly efficiency of the crankshaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural view of Embodiment 1 of the present utility model;

[0017] Figure 2 is of the present utility model Figure 1 schematic view at A in;

[0018] Figure 3 is a schematic structural view of the connecting rod journal of the present utility model.

[0019] In the figure: 1 front end shaft, 2 front balance weight, 3 connecting rod journal, 4 rear balance weight, 5 rear end shaft, 6 internal angle screw, 21 inclined weight-reducing cut surface, 22 through hole, 23 key groove, 24 upper screw hole, 31 front connecting shaft, 32 connecting rod journal body, 33 rear connecting shaft, 34 key, 35 lower screw hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will describe in detail the specific embodiments of the present utility model with reference to the accompanying drawings, so that those skilled in the art can more clearly understand how to practice the present utility model. Although the present utility model is described in conjunction with its preferred specific embodiments, these embodiments are only illustrative and do not limit the scope of the present utility model.

[0021] Specific Embodiment 1: Please refer to Figures 1-3 a low-friction and lightweight engine crankshaft structure, the crankshaft is an assembled crankshaft, including: a front end shaft 1, a front balance weight 2, a connecting rod journal 3, a rear balance weight 4, and a rear end shaft 5 arranged in sequence. This crankshaft also includes two internal angle screws 6. Among them, the front balance weight 2 and the rear balance weight 4 are connected through the connecting rod journal 3 and the internal angle screws 6. Through the above settings, this crankshaft has the advantages of being lightweight, having a simple structure, and being easy to assemble.

[0022] The front balance weight 2 and the rear balance weight 4 have the same structure. The following will take the front balance weight 2 as an example for description.

[0023] On the outer side of the top of the front balance weight 2, an inclined weight-reducing section 21 is provided. A through hole 22 is provided on the inclined weight-reducing section 21 along the direction parallel to the axis of the front end shaft 1. A keyway 23 is provided on the inner top of the through hole 22 along the axis direction of the through hole 22; a top screw hole 24 is provided on the top of the front balance weight 2 perpendicular to the axis of the front end shaft 1. At the same time, the opening direction of the top screw hole 24 is perpendicular to and intersects with the opening direction of the keyway 23.

[0024] The connecting rod journal 3 is a hollow tubular structure. The connecting rod journal 3 is composed of a front connecting shaft 31, a connecting rod journal body 32, and a rear connecting shaft 33 arranged in sequence. Among them, the front connecting shaft 31 and the rear connecting shaft 33 have the same size, and the outer diameters of the front connecting shaft 31 and the rear connecting shaft 33 are adapted to the inner diameter of the through hole 22; the outer diameter of the connecting rod journal body 32 is larger than the outer diameters of the front connecting shaft 31 and the rear connecting shaft 33. In this way, limit steps are formed between the front connecting shaft 31 and the connecting rod journal body 32 and between the connecting rod journal body 32 and the rear connecting shaft 33, and the limit steps can make the assembly positioning accurate and convenient;

[0025] Further, strip-shaped keys 34 are also provided on the outer circumferences of the front connecting shaft 31 and the rear connecting shaft 33, and the two keys 34 are located on both sides of the connecting rod journal body 32; a lower screw hole 35 is also provided on each key 34, and the inner diameter of the lower screw hole 35 is the same as that of the upper screw hole 24; after assembly, the front connecting shaft 31 and the rear connecting shaft 33 respectively penetrate through the through holes 22 at corresponding positions, and the two keys 34 are respectively inserted into the key grooves 23 at corresponding positions. At this time, the upper screw hole 24 and the lower screw hole 35 at the corresponding positions are coaxial, and the internal angle screw 6 is arranged in the upper screw hole 24 and the lower screw hole 35. It can be understood that at this time, the internal angle screw 6 is in threaded connection with both the key 34 and the balance weight. Through such a setting, the connecting rod journal 3 is fixedly connected to the balance weights on both sides. In addition, it should be noted that the cooperation between the key 34 and the key groove 23 enables the connecting rod journal 3 to rotate circumferentially with the balance weights on both sides synchronously without relative sliding, improving the stability of the present crankshaft.

[0026] In this embodiment, in order to ensure the stability of the structure, at least part of the outer ends of the front connecting shaft 31 and the rear connecting shaft 33 are located outside the inclined weight-reducing cut surfaces 21 at their respective positions, and at the same time, the outer end surfaces of the keys 34 are flush with the inclined weight-reducing cut surfaces 21.

[0027] Through this technical solution, by arranging a connecting rod journal between the front balance weight and the rear balance weight, the connecting rod journal is inserted into both the front balance weight and the rear balance weight, and at the same time, the connecting rod journal is fixedly connected to the front balance weight and the rear balance weight through internal angle screws. The connecting rod journal is of a tubular structure. With such a design, the structure of the present crankshaft is simple and easy to assemble, which is beneficial to improving the assembly efficiency of the crankshaft.

[0028] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-friction and lightweight engine crankshaft structure, characterized in that: It includes a front end shaft (1), a front balance weight (2), a connecting rod journal (3), a rear balance weight (4), and a rear end shaft (5) arranged in sequence. Among them, the connecting rod journal (3) is a tubular structure, and both the front balance weight (2) and the rear balance weight (4) are inserted into the connecting rod journal (3); the crankshaft further includes a number of internal angle screws (6), and the connecting rod journal (3) is fixed to the front balance weight (2) and the rear balance weight (4) through the internal angle screws (6).

2. The low-friction and lightweight engine crankshaft structure according to claim 1, characterized in that: The connecting rod journal (3) is composed of a front connecting shaft (31), a connecting rod journal body (32), and a rear connecting shaft (33) arranged in sequence; through holes (22) are both opened at the top of the front balance weight (2) and the rear balance weight (4) along the direction parallel to the axis of the front end shaft (1); the front connecting shaft (31) penetrates through the through hole (22) of the front balance weight (2), and the rear connecting shaft (33) penetrates through the through hole (22) of the rear balance weight (4); the connecting rod journal body (32) is located between the front balance weight (2) and the rear balance weight (4).

3. The structure of a low-friction and lightweight engine crankshaft according to claim 2, characterized in that: The outer diameter of the connecting rod journal body (32) is larger than the outer diameters of the front connecting shaft (31) and the rear connecting shaft (33).

4. A low-friction lightweight engine crankshaft structure according to claim 2, characterized in that: Both between the front connecting shaft (31) and the front balance weight (2) and between the rear connecting shaft (33) and the rear balance weight (4) are fixedly connected through internal angle screws (6).

5. A low-friction lightweight engine crankshaft structure according to claim 4, characterized in that: An upper screw hole (24) communicating with the through hole (22) is opened at the top of the front balance weight (2); the internal angle screw (6) penetrates through the upper screw hole (24) and is threadedly connected to the front connecting shaft (31).

6. A low-friction and lightweight engine crankshaft structure according to claim 5, characterized in that: The axis of the internal angle screw (6) is perpendicular to the axis of the front connecting shaft (31).

7. A low-friction and lightweight engine crankshaft structure according to claim 2, characterized in that: Key grooves (23) are both opened on the inner walls of the through holes (22) of the front balance weight (2) and the rear balance weight (4); keys (34) matching with the key grooves (23) at corresponding positions are both provided on the outer circumferences of the front connecting shaft (31) and the rear connecting shaft (33).

8. A low-friction and lightweight engine crankshaft structure according to claim 7, characterized in that: Oblique weight-reducing cut surfaces are both opened on the outer sides of the tops of the front balance weight (2) and the rear balance weight (4).

9. A low-friction lightweight engine crankshaft structure according to claim 8, characterized in that: The outer end surfaces of the keys (34) are flush with the oblique weight-reducing cut surfaces at corresponding positions.

10. A low-friction and lightweight engine crankshaft structure according to claim 2, characterized in that: The connecting rod journal (3) and the front balance weight (2) and the rear balance weight (4) are all in a tight fit.

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