Engine crankshaft, balance weight structure and engine

Abstract

The utility model belongs to the technical field of motorcycle engines, and particularly discloses an engine crankshaft, a balance weight structure and an engine. The engine crankshaft and balance weight structure comprises a main shaft, the main shaft is used for receiving rotating power, the main shaft is provided with at least one pair of crank arms, a piston rod is arranged between the crank arms, each crank arm comprises a first balance weight, and the main shaft is provided with a driving gear; the transmission mechanism comprises a balance shaft and a driven gear, the driven gear is meshed with the driving gear, a second balancing weight is arranged on the driven gear, and the second balancing weight and the driven gear are integrally arranged; when the piston rod is located at the upper dead center, a target angle is formed between the symmetry plane of the first balancing weight and the symmetry plane of the second balancing weight. Through the interaction of the first balancing weight and the second balancing weight, the inertia force in the engine can be balanced, so that the vibration reduction effect is achieved, and more comfortable driving experience is provided for a driver.

Description

Technical Field

[0001] The utility model relates to the technical field of motorcycle engines, in particular to an engine crankshaft and a balancing weight structure and an engine. Background Art

[0002] The combustion of fuel in the cylinder of a motorcycle engine generates heat energy, which is converted into mechanical energy and then drives the wheels of the motorcycle through the crankshaft to make the motorcycle move. Due to the limited space on a motorcycle, its engine has the advantages of small size and low noise.

[0003] In motorcycle engine assemblies, counterweights are typically installed on the crankshaft to reduce noise and engine vibration, thereby improving riding comfort. In the prior art, engines are equipped with a timing drive system and a cooling system in addition to the crankshaft. These systems also generate vibrations during operation, causing noise and degrading the user experience. In light of this, the applicant has proposed an engine crankshaft and counterweight structure, as well as an engine. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an engine crankshaft and a balance weight structure and an engine, which are used to solve the problem in the prior art that the vibration generated by various systems of the motorcycle engine during operation affects the driving experience.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides an engine crankshaft and balancing weight structure, comprising:

[0006] A main shaft, the main shaft is used to receive rotational power, the main shaft is provided with at least a pair of crank arms, a piston rod is provided between the crank arms, the crank arms include a first counterweight block, and the main shaft is provided with a driving gear;

[0007] A transmission mechanism, the transmission mechanism comprising a balance shaft and a driven gear, the driven gear meshing with the driving gear, the driven gear being provided with a second counterweight, the second counterweight being integrally arranged with the driven gear;

[0008] When the piston rod is located at the top dead center, the symmetry plane of the first counterweight block and the symmetry plane of the second counterweight block have a target angle.

[0009] Optionally, the target angle is ±2°.

[0010] Optionally, the main shaft includes a first crankshaft and a second crankshaft, the crank arm is arranged at one end where the first crankshaft and the second crankshaft are close to each other, and the driving wheel is detachably connected to the first crankshaft.

[0011] Optionally, a first connecting portion is provided on the first crankshaft, a second connecting portion cooperating with the first connecting portion is provided on the driving gear, and a limiting member for fixing the driving gear is provided at one end of the first crankshaft away from the second crankshaft.

[0012] Optionally, the transmission mechanism further includes a timing sprocket and a cooling assembly, wherein the timing sprocket and the cooling assembly are arranged on the balance shaft, and the driven gear is arranged between the timing sprocket and the cooling assembly.

[0013] Optionally, the second counterweight block includes a first boss and a second boss, the first boss is arranged on the driven gear, the first boss extends circumferentially on the driven gear with the axis of the driven gear as the center, the second boss extends vertically on the first boss along the direction of the driven gear toward the cooling component, and the width of the second boss is smaller than the width of the first boss.

[0014] Optionally, the cooling assembly includes a water pump impeller and a locking piece, the water pump impeller is arranged on the balance shaft and is located at the end of the driven gear away from the timing sprocket, and the locking piece is fixed to the end of the balance shaft for fixing the water pump impeller.

[0015] Optionally, a fixed shaft is provided between the crank arms, the fixed shaft passes through the crank arms, the piston rod is rotatably connected to the fixed shaft, a first avoidance opening is opened on the first crankshaft for avoiding the fixed shaft, and a second avoidance opening is opened on the second crankshaft for avoiding the fixed shaft.

[0016] Optionally, the first counterweight block is circumferentially extended with the axis of the first crankshaft as the center, and the first counterweight block has a first portion located in the middle of the first counterweight block and a second portion symmetrically arranged on both sides of the first portion. The first portion and the second portion are continuously arranged, and the width of the first portion is smaller than that of the second portion.

[0017] The utility model also provides an engine, which includes the above-mentioned engine crankshaft and balance weight structure.

[0018] As described above, the engine crankshaft and balance weight structure and engine proposed in the present invention have the following beneficial effects:

[0019] (1) Compared with the prior art, the present invention provides a first counterweight block and a second counterweight block, which have a corresponding relationship. After integrating the counterweight, timing and cooling functions, the first counterweight block and the second counterweight block move synchronously under the drive of the crankshaft. The cooperation between the first counterweight block and the second counterweight block can enhance the shock absorption effect and reduce the noise generated inside the engine.

[0020] (2) Compared with the prior art, the present invention makes assembly more convenient by integrating the second counterweight block with the driven gear. At the same time, the second counterweight block does not need to be provided separately, thus avoiding excessive occupation of the internal space of the engine and making the entire transmission structure more compact.

[0021] (3) Compared with the prior art, the present invention integrates the first counterweight, timing sprocket and cooling water pump inside the engine into one, eliminating the need for excessive gear transmission, thereby greatly reducing the space required for the three functional parts. Accordingly, the overall size of the engine can be reduced, and the overall weight of the engine will be reduced accordingly, thereby meeting the demand for lightweight motorcycle engines and improving the performance of racing motorcycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a schematic structural diagram of an embodiment of the present utility model;

[0023] Figure 2 Shown is a schematic structural diagram of the back portion of an embodiment of the present utility model;

[0024] Figure 3 Shown is a side view of an embodiment of the present invention;

[0025] Figure 4 Shown is a front view of an embodiment of the present utility model;

[0026] Figure 5 Shown is a structural schematic diagram of a transmission mechanism in one embodiment of the present utility model.

[0027] Description of reference numerals:

[0028] First crankshaft 1, first avoidance opening 101, second crankshaft 2, second avoidance opening 201, crank arm 3, piston rod 4, first counterweight 5, first part 501, second part 502, driving gear 6, limit member 7, balance shaft 8, driven gear 9, bushing 10, second counterweight 11, first boss 1101, second boss 1102, timing sprocket 12, water pump impeller 13, locking member 14, fixed shaft 15. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present invention.

[0030] It should be noted that the diagrams provided in this embodiment are only used to illustrate the basic concept of the present invention. Therefore, the diagrams only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in actual implementation can be changed at will, and the component layout type may also be more complex. The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read. They are not used to limit the conditions for the implementation of the present invention, so they have no technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the effect and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0031] like Figure 1-Figure 5 As shown, the utility model provides an engine crankshaft and a balancing weight structure and an engine.

[0032] In one exemplary embodiment, an engine crankshaft and balance weight structure includes:

[0033] The main shaft is used to receive rotational power. The main shaft is provided with at least one pair of crank arms 3. A piston rod 4 is provided between the crank arms 3. The crank arms 3 include a first counterweight 5. The main shaft is provided with a driving gear 6.

[0034] The transmission mechanism includes a balance shaft 8 and a driven gear 9. The driven gear 9 is meshed with the driving gear 6. A second counterweight 11 is provided on the driven gear 9. The second counterweight 11 is integrally provided with the driven gear 9.

[0035] When the piston rod 4 is located at the top dead center, the symmetry plane of the first counterweight 5 and the symmetry plane of the second counterweight 11 have a target angle.

[0036] In this embodiment, by setting up a first counterweight 5 and a second counterweight 11, and having a corresponding relationship between the two, after integrating the counterweight, timing and cooling functions, they move synchronously driven by the crankshaft. The first counterweight 5 and the second counterweight 11 cooperate with each other to enhance the shock absorption effect and reduce the noise generated inside the engine.

[0037] At the same time, in this embodiment, by integrating the first counterweight 5, the timing sprocket 12 and the cooling water pump inside the engine into one, there is no need to use too many gears for transmission, which greatly reduces the space required for the three functional parts. Correspondingly, the overall size of the engine can be reduced, and the overall weight of the engine will be reduced accordingly, which increases the demand for lightweight motorcycle engines and improves the performance of racing motorcycles.

[0038] In an exemplary embodiment, the target angle is ±2°.

[0039] In this embodiment, when at top dead center, the first counterweight 5 and the second counterweight 11 form an angle within a range of ±2°. As the driving gear 6 drives the driven gear 9 to rotate, the first counterweight 5 provides vibration and noise reduction for the crankshaft assembly, while the second counterweight 11 provides vibration and noise reduction for the entire balance shaft 8. Since the balance shaft 8 is indirectly driven by the crankshaft, there is a corresponding relationship between the two. Therefore, the coordinated effect between the first counterweight 5 and the second counterweight 11 enhances the vibration reduction effect of the entire engine assembly and reduces noise during driving.

[0040] Exemplarily, in this embodiment, the target angle is 1°.

[0041] Exemplarily, in this embodiment, the target angle is -1°.

[0042] It is worth noting that, in this embodiment, the sizes of the first counterweight 5 and the second counterweight 11 can vary relatively, but the angle formed by their symmetry centers remains unchanged.

[0043] It should also be noted that in this embodiment, since the target angle range is within ±2°, the angular coordination between the first counterweight 5 and the second counterweight 11 prevents them from being symmetrically aligned. This improves vibration and noise reduction, reduces wear between internal engine components, and extends the engine's service life. Furthermore, improved balance reduces energy loss during power transmission, thereby improving the engine's power output efficiency and enabling the engine to better adapt to varying operating conditions and load requirements.

[0044] In an exemplary embodiment, the main shaft includes a first crankshaft 1 and a second crankshaft 2 , the crank arm 3 is disposed at one end of the first crankshaft 1 and the second crankshaft 2 close to each other, and the driving wheel is detachably connected to the first crankshaft 1 .

[0045] In this embodiment, a first crankshaft 1 and a second crankshaft 2 are set, and a driving wheel is set on the first crankshaft 1. After the driving wheel is connected to the rotational power, it can drive the first crankshaft 1 and the second crankshaft 2 to rotate, and synchronously drive the crank arm 3 to rotate, so as to realize the up and down movement of the piston rod 4.

[0046] For example, the present invention is mainly used for a single-cylinder motorcycle engine. The number of crank arms 3 is two, and correspondingly, the number of piston rod 4 is one. During the rotation of the crankshaft, the piston rod 4 can be driven to move along the axial direction of the cylinder body.

[0047] Exemplarily, a first connecting portion is provided on the first crankshaft 1, a second connecting portion that cooperates with the first connecting portion is provided on the driving gear 6, and a limiter 7 for fixing the driving gear 6 is provided at one end of the first crankshaft 1 away from the second crankshaft 2. In this embodiment, the first connecting portion and the second connecting portion are provided, so that the first crankshaft 1 and the driving gear 6 can be matched and connected. The first connecting portion in this embodiment adopts a gear integrally formed on the first crankshaft 1, and the second connecting portion adopts a gear integrally formed on the driving gear 6 and capable of cooperating with the first connecting portion. The two gears are meshed with each other. After the driving gear 6 is inserted into the first connecting portion, the limiter 7 is installed at the end of the first crankshaft 1 to fix the driving gear 6 on the first crankshaft 1. The limiter 7 in this embodiment adopts a locking nut, which can be threadedly connected to the first crankshaft 1 to fix the driving gear 6.

[0048] In an exemplary embodiment, the transmission mechanism further includes a timing sprocket 12 and a cooling assembly. The timing sprocket 12 and the cooling assembly are disposed on the balance shaft 8 , and the driven gear 9 is disposed between the timing sprocket 12 and the cooling assembly.

[0049] Exemplarily, the second counterweight 11 includes a first boss 1101 and a second boss 1102, the first boss 1101 being arranged on the driven gear 9, the first boss 1101 extending circumferentially on the driven gear 9 with the axis of the driven gear 9 as the center, the second boss 1102 extending vertically on the first boss 1101 along the direction of the driven gear 9 toward the cooling assembly, and the width of the second boss 1102 is smaller than the width of the first boss 1101.

[0050] In this embodiment, the second counterweight 11 is mainly used to ensure engine shock absorption and engine stability. Specifically, in this embodiment, the second counterweight 11 is integrated into the right side wall of the driven gear 9, so that the second counterweight 11 can be installed synchronously when the driven gear 9 is installed.

[0051] For example, in this embodiment, the second counterweight 11 comprises two parts. The first part extends circumferentially and is disposed on the driven gear 9, with an overall annular shape. The second boss 1102 is formed by extending the outer edge of the first boss 1101 toward the axial direction of the driven gear 9 and in the direction of the cooling assembly. The width of the second boss 1102 is smaller than that of the first boss 1101, allowing the second boss 1102 to be positioned away from the balance shaft 8 to facilitate installation of the cooling assembly. If the width of the first boss 1101 is insufficient, a portion of the second boss 1102 may extend onto the surface of the driven gear 9. However, in the design, this should not affect the mating relationship between the meshing driving gear 6 and the first boss 1101.

[0052] In this embodiment, after the driving gear 6 receives the rotational power, the driven gear 9 meshing with the driving gear 6 will drive the balance shaft 8 to rotate, thereby driving the timing sprocket 12 and the water pump impeller 13 in the cooling assembly to rotate, realizing the functions of the timing system and cooling.

[0053] Exemplarily, the cooling assembly includes a water pump impeller 13 and a locking member 14. The water pump impeller 13 is arranged on the balance shaft 8 and is located at the end of the driven gear 9 away from the timing sprocket 12. The locking member 14 is fixed to the end of the balance shaft 8 for fixing the water pump impeller 13.

[0054] Exemplarily, a shaft sleeve 10 is provided on the driven gear 9, and the driven gear 9 is detachably connected to the balance shaft 8 through the shaft sleeve 10, and the second counterweight 11 is provided between the driven gear 9 and the cooling assembly.

[0055] Exemplarily, the timing sprocket 12 is arranged on the side of the driven gear 9 away from the counterweight, and the timing sprocket 12 is arranged on the shaft sleeve 10. In this embodiment, the timing sprocket 12 is arranged on the left side of the driven gear 9, and the counterweight is arranged on the right end face of the driven gear 9.

[0056] In this embodiment, by integrating the driven gear 9 and the timing sprocket 12 into the sleeve 10, when connecting, it is only necessary to install the sleeve 10 on the balance shaft 8 to achieve the connection between the driven gear 9, the timing sprocket 12 and the fixed shaft 15. The sleeve 10, the driven gear 9 and the timing sprocket 12 can also be connected in a split manner to facilitate replacement.

[0057] It is worth noting that the size of the second counterweight 11 is adaptively set according to the specific model of the engine. The size of the second counterweight 11 (ie, the angle of circumferential extension) can be adjusted according to the size and performance requirements of the engine.

[0058] It should also be noted that in this embodiment, the inner edge of the first boss 1101 can also be integrally fixed to the shaft sleeve 10, which can improve the overall performance of the connector and make assembly more convenient.

[0059] It should also be noted that a plurality of weight-reducing holes are provided in the portion of the counterweight block that does not cover the driven gear 9 to reduce the overall weight of the driven gear 9, thereby reducing the overall weight of the engine and improving lightweight performance. The weight-reducing holes are also evenly distributed along the circumference of the driven gear 9.

[0060] In an exemplary embodiment, a fixed shaft 15 is provided between the crank arms 3, the fixed shaft 15 is set through the crank arms 3, the piston rod 4 is rotatably connected to the fixed shaft 15, a first avoidance opening 101 for avoiding the fixed shaft 15 is opened on the first crankshaft 1, and a second avoidance opening 201 for avoiding the fixed shaft 15 is opened on the second crankshaft 2.

[0061] In this embodiment, a fixed shaft 15 is provided, rotatably connected to the piston rod 4. When the crank arm 3 rotates, the piston rod 4 can reciprocate along the interior of the cylinder. The provision of the first and second relief openings 101 and 201 makes the entire crankshaft assembly more compact, positioning the crankshaft axis further upward, reducing the internal space occupied by the crankshaft assembly and the size of the engine.

[0062] In an exemplary embodiment, the first counterweight 5 is circumferentially extended with the axis of the first crankshaft 1 as the center, and the first counterweight 5 has a first portion 501 located in the middle of the first counterweight 5 and a second portion 502 symmetrically arranged on both sides of the first portion 501. The first portion 501 and the second portion 502 are continuously arranged, and the width of the first portion 501 is smaller than that of the second portion 502.

[0063] In this embodiment, the width of the first part 501 is smaller than the width of the second part 502, so that the radius between the first part 501 and the axis center of the first crankshaft 1 is smaller than the radius between the first part 501 and the axis center of the first crankshaft 1, which can correspondingly reduce the overall size of the crank arm 3, correspondingly reduce the volume of the engine, and reduce the overall weight of the engine.

[0064] In an exemplary embodiment, when the piston rod 4 is at the top dead center, the piston rod 4 is in a tilted state, and the tilt direction is from the upper left to the lower right. Correspondingly, the cylinder body corresponding to the piston should also be tilted at the same angle. This setting makes the center of the engine further back, which is beneficial to the overall performance of the motorcycle, especially racing and non-racing motorcycles, can improve the stability and handling of the vehicle, reduce the risk of skidding or overturning, and may improve driving comfort.

[0065] The utility model also provides an engine, which includes the above-mentioned engine crankshaft and balance weight structure.

[0066] In summary, the present invention can balance the inertial force inside the engine through the interaction between the first counterweight 5 and the second counterweight 11, thereby achieving a vibration reduction effect and providing the driver with a more comfortable driving experience.

[0067] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed in the present invention are intended to be covered by the claims of the present invention.

Claims

1. An engine crankshaft and balance weight structure, characterized in that: include: A main shaft, the main shaft is used to receive rotational power, the main shaft is provided with at least a pair of crank arms, a piston rod is provided between the crank arms, the crank arms include a first counterweight block, and the main shaft is provided with a driving gear; A transmission mechanism, the transmission mechanism comprising a balance shaft and a driven gear, the driven gear meshing with the driving gear, the driven gear being provided with a second counterweight, the second counterweight being integrally arranged with the driven gear; When the piston rod is located at the top dead center, the symmetry plane of the first counterweight block and the symmetry plane of the second counterweight block have a target angle.

2. The engine crankshaft and balance weight structure according to claim 1, characterized in that: The target angle is ±2°.

3. The engine crankshaft and balance weight structure according to claim 2, characterized in that: The main shaft includes a first crankshaft and a second crankshaft. The crank arm is arranged at one end of the first crankshaft and the second crankshaft that are close to each other. A driving wheel is detachably connected to the first crankshaft.

4. The engine crankshaft and balance weight structure according to claim 3, characterized in that: The first crankshaft is provided with a first connecting portion, the driving gear is provided with a second connecting portion that cooperates with the first connecting portion, and an end of the first crankshaft away from the second crankshaft is provided with a limiting member for fixing the driving gear.

5. The engine crankshaft and balance weight structure according to claim 1, characterized in that: The transmission mechanism further includes a timing sprocket and a cooling assembly, wherein the timing sprocket and the cooling assembly are arranged on the balance shaft, and the driven gear is arranged between the timing sprocket and the cooling assembly.

6. The engine crankshaft and balance weight structure according to claim 5, characterized in that: The second counterweight block includes a first boss and a second boss. The first boss is arranged on the driven gear. The first boss extends circumferentially on the driven gear with the axis of the driven gear as the center. The second boss extends vertically on the first boss along the direction of the driven gear toward the cooling component. The width of the second boss is smaller than the width of the first boss.

7. The engine crankshaft and balance weight structure according to claim 6, characterized in that: The cooling assembly includes a water pump impeller and a locking piece. The water pump impeller is arranged on the balance shaft and is located at the end of the driven gear away from the timing sprocket. The locking piece is fixed to the end of the balance shaft for fixing the water pump impeller.

8. The engine crankshaft and balance weight structure according to claim 3, characterized in that: A fixed shaft is provided between the crank arms, the fixed shaft passes through the crank arms, the piston rod is rotatably connected to the fixed shaft, a first avoidance opening is provided on the first crankshaft for avoiding the fixed shaft, and a second avoidance opening is provided on the second crankshaft for avoiding the fixed shaft.

9. The engine crankshaft and balance weight structure according to claim 3, characterized in that: The first counterweight block is circumferentially extended with the axis of the first crankshaft as the center. The first counterweight block has a first portion located in the middle of the first counterweight block and a second portion symmetrically arranged on both sides of the first portion. The first portion and the second portion are continuously arranged, and the width of the first portion is smaller than that of the second portion.

10. An engine, characterized in that: The invention comprises an engine crankshaft and a balancing weight structure as described in any one of claims 1 to 9.

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