Crankshaft structure of motorcycle engine

Abstract

The utility model discloses a crankshaft structure of a motorcycle engine, which comprises two groups of crank components connected with each other, each crank component comprises an inner crank and an outer crank, a piston connecting rod is arranged between the inner crank and the outer crank, the two inner cranks are fixedly connected, and crankshafts are arranged at the outer ends of the two outer cranks. Notches are formed in the two sides of the upper half portion of the outer crank, a first connecting part connected with a piston connecting rod is formed between the two notches, grooves are formed in the two sides of the upper half portion of the inner crank, and a second connecting part connected with the piston connecting rod is formed between the two grooves. The crank has the advantages that the notch or the groove is formed in the crank, so that the weights of the upper part and the lower part of the crank are different, the crank can generate centrifugal force after rotating, the operation efficiency of the piston is higher, and the power consumption of the engine is reduced.

Description

Technical Field

[0001] The utility model relates to a crankshaft structure, in particular to a crankshaft structure of a motorcycle engine. Background Art

[0002] The crankshaft is the most important component in the engine. It bears the force transmitted from the piston and connecting rod, and converts it into torque, which is output through the crankshaft and drives other accessories on the engine. The crankshaft is subjected to the combined effects of the centrifugal force of the rotating mass, the periodically changing gas inertia force and the reciprocating inertia force, causing the crankshaft to be subjected to bending and torsional loads.

[0003] For example, a support structure of a crankshaft assembly for an engine with publication number CN208252694U includes a crankset and a support, wherein the support is arranged between two cranksets of the crankshaft assembly.

[0004] In the above-mentioned crankshaft structure, the crank is a circular structure. When the crank rotates, the centrifugal force provided by the crank itself is relatively small, and the rotation of the crank is mostly driven by the engine, resulting in greater power consumption of the engine. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a crankshaft structure of a motorcycle engine.

[0006] The technical solution adopted by the utility model to solve the above-mentioned technical problems is: a crankshaft structure of a motorcycle engine, characterized in that it includes two groups of connected crank assemblies, the crank assembly includes an inner crank and an outer crank, a piston connecting rod is arranged between the inner crank and the outer crank, the two inner cranks are fixedly connected, and the outer ends of the two outer cranks are each provided with a crankshaft, notches are provided on both sides of the upper half of the outer crank, and a first connecting portion connected to the piston connecting rod is formed between the two notches, and grooves are provided on both sides of the upper half of the inner crank, and a second connecting portion connected to the piston connecting rod is formed between the two grooves.

[0007] A further preferred solution of the present invention is that the lower half of the outer crank is the first counterweight portion, and a transition portion is provided between the first connecting portion and the first counterweight portion.

[0008] A further preferred solution of the present invention is that the outer edge of the transition portion is in an inwardly concave arc shape.

[0009] A further preferred solution of the present invention is that the first counterweight portion is provided with a thickened portion extending along the axial direction of the outer crank.

[0010] A further preferred solution of the present invention is that the lower half of the inner crank is a second counterweight portion, and the second counterweight portion is provided with a protrusion with the same shape as the second counterweight portion.

[0011] A further preferred solution of the present invention is that the side edge of the second connecting portion and the top edge of the second counterweight portion form the groove, and the angle between the side edge of the second connecting portion and the top edge of the second counterweight portion is 90°.

[0012] A further preferred solution of the present invention is that: an inner crankshaft is provided on each of the two inner cranks, and the two inner crankshafts are fixedly connected.

[0013] A further preferred solution of the present invention is that a fixing bracket is provided between the two inner cranks, and the fixing bracket is sleeved on the inner crankshaft.

[0014] A further preferred solution of the present invention is that the crank and the crankshaft are integrally formed.

[0015] Compared with the prior art, the advantages of the present invention are that a piston connecting rod is provided between the inner crank and the outer crank, the two inner cranks are fixedly connected, and crankshafts are provided at the outer ends of the two outer cranks. Notches are provided on both sides of the upper half of the outer crank, and a first connection part connected to the piston connecting rod is formed between the two notches. Grooves are provided on both sides of the upper half of the inner crank, and a second connection part connected to the piston connecting rod is formed between the two grooves. Notches or grooves are provided on the crank, so that there is a difference in weight between the upper and lower parts of the crank. After the crank rotates, the crank itself generates centrifugal force, which makes the piston run more efficiently and reduces the power consumption of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described in further detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and should not be construed as limiting the scope of the present invention. Furthermore, unless otherwise specified, the drawings are merely schematic representations of the composition or structure of the depicted objects and may contain exaggerated representations. Furthermore, the drawings are not necessarily drawn to scale.

[0017] Figure 1 This is a schematic structural diagram of a preferred embodiment of the present utility model;

[0018] Figure 2 Schematic diagram of the internal and external cranks in the preferred embodiment of the present utility model;

[0019] Figure 3 Schematic diagram of the inner crank in the preferred embodiment of the present utility model Figure 1 ;

[0020] Figure 4 Schematic diagram of the inner crank in the preferred embodiment of the present utility model Figure 2 .

[0021] In the figure: 1. Inner crank; 11. Inner crankshaft; 12. Groove; 13. Second connecting portion; 14. Second counterweight portion; 15. Protrusion; 2. Outer crank; 21. Crankshaft; 22. Notch; 23. First connecting portion; 24. First counterweight portion; 25. Transition portion; 26. Thickened portion; 3. Fixed bracket; 31. Bearing; 4. Piston connecting rod; a. Side of the second connecting portion; b. Top edge of the second counterweight portion; α. Angle. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely illustrative and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0023] It should be noted that like reference numerals denote like items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in subsequent drawings.

[0024] The crankshaft structure of a motorcycle engine includes two connected crank assemblies. The two crank assemblies are arranged side by side and are respectively connected to two pistons to drive the pistons to do work in the piston chambers.

[0025] The crank assembly includes an inner crank 1 and an outer crank 2. The two inner cranks 1 are integrally provided with an inner crankshaft 11. The two inner crankshafts 11 are fixedly connected. A fixed bracket 3 is provided between the two outer cranks 2. The fixed bracket 3 is sleeved on the inner crankshaft 11 and rotates with the inner crankshaft 11.

[0026] A bearing 31 is provided in the fixing bracket 3 . The bearing 31 is provided between the fixing bracket 3 and the inner crankshaft 11 . The crank is fixed in the engine through the fixing bracket 3 .

[0027] A piston connecting rod 4 is provided between the inner crank 1 and the outer crank 2. A rotating shaft is provided between the inner crank 1 and the outer crank 2. The bottom end of the piston connecting rod 4 is sleeved on the rotating shaft, and the top end of the piston connecting rod 4 is connected to the piston to drive the piston to do work in the piston chamber.

[0028] A crankshaft 21 is provided at the outer end of each of the two outer cranks 2 , and the crankshaft 21 is integrally formed with the outer crank 2 .

[0029] Notches 22 are provided on both sides of the upper half of the outer crank 2 , and a first connecting portion 23 connected to the piston connecting rod 4 is formed between the two notches 22 .

[0030] The lower half of the outer crank 2 is the first counterweight portion 24. A transition portion 25 is provided between the first connecting portion 23 and the first counterweight portion 24. The outer edge of the transition portion 25 is in an inwardly concave arc shape. The provision of the transition portion 25 makes the overall structure of the outer crank 2 more stable.

[0031] The first counterweight portion 24 is provided with a thickened portion 26 extending along the axial direction of the outer crank 2 to increase the weight of the first counterweight portion 24 so that the overall diameter of the outer crank 2 can be made smaller while the weight of the first counterweight portion 24 is made heavier.

[0032] Grooves 12 are provided on both sides of the upper half of the inner crank 1 , and a second connecting portion 13 connected to the piston connecting rod 4 is formed between the two grooves 12 .

[0033] The lower half of the inner crank 1 is the second counterweight portion 14, and the second counterweight portion 14 is provided with a protrusion 15 with the same shape as the second counterweight portion 14. By increasing the weight of the second counterweight portion 14, the overall diameter of the inner crank 1 can be made smaller, and the weight of the second counterweight portion 14 can be made heavier.

[0034] The side of the second connecting portion 13 and the top of the second counterweight portion 14 form a groove 12, and the angle α between the side a of the second connecting portion and the top b of the second counterweight portion is 90°, so that the groove 12 is maximized and the weight difference between the second connecting portion 13 and the second counterweight portion 14 is greater.

[0035] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the product of the present invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0036] The above describes in detail the crankshaft structure of the motorcycle engine provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The above examples are intended only to facilitate understanding of the present invention and its core concepts. It should be noted that those skilled in the art may, without departing from the principles of the present invention, make various improvements and modifications to the present invention, and such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A crankshaft structure for a motorcycle engine, characterized in that: The invention comprises two connected crank assemblies, wherein the crank assembly comprises an inner crank and an outer crank, a piston connecting rod is arranged between the inner crank and the outer crank, the two inner cranks are fixedly connected, and crankshafts are arranged at the outer ends of the two outer cranks, notches are provided on both sides of the upper half of the outer crank, and a first connecting part connected to the piston connecting rod is formed between the two notches, and grooves are provided on both sides of the upper half of the inner crank, and a second connecting part connected to the piston connecting rod is formed between the two grooves.

2. The crankshaft structure of a motorcycle engine according to claim 1, characterized in that: The lower half of the outer crank is a first counterweight portion, and a transition portion is provided between the first connecting portion and the first counterweight portion.

3. The crankshaft structure of a motorcycle engine according to claim 2, characterized in that: The outer edge of the transition portion is in an inwardly concave arc shape.

4. The crankshaft structure of a motorcycle engine according to claim 2, characterized in that: The first counterweight portion is provided with a thickened portion extending along the axial direction of the outer crank.

5. The crankshaft structure of a motorcycle engine according to claim 1, characterized in that: The lower half of the inner crank is a second counterweight portion, and the second counterweight portion is provided with a protrusion with the same shape as the second counterweight portion.

6. The crankshaft structure of a motorcycle engine according to claim 5, characterized in that: The side edge of the second connecting portion and the top edge of the second counterweight portion form the groove, and the angle between the side edge of the second connecting portion and the top edge of the second counterweight portion is 90°.

7. The crankshaft structure of a motorcycle engine according to claim 1, characterized in that: An inner crankshaft is provided on each of the two inner cranks, and the two inner crankshafts are fixedly connected.

8. The crankshaft structure of a motorcycle engine according to claim 7, characterized in that: A fixing bracket is further provided between the two inner cranks, and the fixing bracket is sleeved on the inner crankshaft.

9. The crankshaft structure of a motorcycle engine according to claim 1, characterized in that: The crank and the crankshaft are integrally formed.

Images