Engine crankshaft, balance weight structure and engine

Abstract

The invention 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 interaction of the first balancing weight and the second balancing weight, 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 invention 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 to rotate through the crankshaft to enable the motorcycle to move. Due to the limited space in a motorcycle, its engine has the advantages of small size and low noise.

[0003] In the engine assembly of a motorcycle, a counterweight is usually arranged on the crank to reduce noise and vibration of the engine, thereby improving driving comfort. In the prior art, in addition to the crankshaft, the engine is also provided with a timing transmission system and a cooling system. When each system is working, vibration will also be generated, causing noise and reducing the user experience. In view of this, the applicant proposes an engine crankshaft and a balancing weight structure, and an engine. Summary of the invention

[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 balancing weight structure, and an engine, which are used to solve the problem in the prior art that the vibration generated by various systems of motorcycle engines during operation affects the driving experience.

[0005] To achieve the above objectives and other related objectives, the present invention provides an engine crankshaft and a 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 one pair of crank arms, a piston rod is provided between the crank arms, the crank arms include a first counterweight, and the main shaft is provided with a driving gear;

[0007] A transmission mechanism, the transmission mechanism comprising a balancing shaft and a driven gear, the driven gear meshing with the driving gear, a second counterweight block being arranged on the driven gear, and the second counterweight block 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 gear 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 from the driven gear to 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 an 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 for avoiding the fixed shaft is opened on the first crankshaft, and a second avoidance opening for avoiding the fixed shaft is opened on the second crankshaft.

[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 arranged continuously, and the width of the first portion is smaller than that of the second portion.

[0017] The present invention 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 the engine proposed by 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, and the two have a corresponding relationship. After integrating the counterweight, timing and cooling functions, they move synchronously driven by the crankshaft. The first counterweight block and the second counterweight block cooperate with each other to 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 block, the timing sprocket and the cooling water pump inside the engine into one body, eliminating the need for excessive gear transmission, thereby greatly reducing the space required for the three functional parts. The overall size of the engine can be reduced accordingly, 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 invention;

[0023] Figure 2 Shown is a schematic structural diagram of the back in one embodiment of the present invention;

[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 invention;

[0026] Figure 5 It is a schematic structural diagram of a transmission mechanism in one embodiment of the present invention.

[0027] Description of reference numerals:

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

[0029] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0030] It should be noted that the diagram provided in the present embodiment only illustrates the basic concept of the present invention in a schematic manner, so the diagram only shows the components related to the present invention rather than drawing according to the number, shape and size of the components during actual implementation. The type, quantity and ratio of each component during actual implementation can be a random change, and the component layout type may also be more complicated. The structure, ratio, size, etc. illustrated in the drawings of the present specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that the present invention can implement, so they have no technical substantive 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 by the present invention without affecting the effect that the present invention can produce and the purpose that can be achieved. 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 narration, and are not used to limit the scope of the present invention. The change or adjustment of its relative relationship should also be regarded as the scope of the present invention without substantially changing the technical content.

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

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

[0033] A main shaft, 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 block 5, and a driving gear 6 is provided on the main shaft;

[0034] The transmission mechanism includes a balancing 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, and the second counterweight 11 is integrally arranged 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, and the first counterweight 5 and the second counterweight 11 cooperate to enhance the shock absorbing 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. The overall size of the engine can be reduced accordingly, 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 located at the top dead center, there is a certain angle between the first counterweight 5 and the second counterweight 11, and the angle range between the two is ±2°. In the process of the driving gear 6 driving the driven gear 9 to rotate, the first counterweight 5 reduces the vibration and noise of the crankshaft assembly, and the second counterweight 11 reduces the vibration and noise of 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, under the cooperation between the first counterweight 5 and the second counterweight 11, the vibration reduction effect of the entire engine assembly is better, and the noise generated during driving is smaller.

[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 be relatively changed, but the angle relationship formed by the symmetry centers of the two remains unchanged.

[0043] It should also be noted that in this embodiment, since the target angle interval is located at ±2°, the first counterweight 5 and the second counterweight 11 are not in symmetrical synchronization through the angle matching relationship, which is more conducive to improving the shock absorption and noise reduction performance, and at the same time can reduce the wear between the internal parts of the engine and extend the service life of the engine. In addition, better balance can reduce the energy loss in the power transmission process, thereby improving the power output efficiency of the engine, and at the same time, it can enable the engine to better adapt to different working 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 where the first crankshaft 1 and the second crankshaft 2 are close to each other, and the driving gear 6 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 gear 6 is set on the first crankshaft 1. After the driving gear 6 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] Exemplarily, 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, and the rotation of the crankshaft can drive the piston rod 4 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 cooperating with the first connecting portion is provided on the driving gear 6, and a stopper 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 can be matched and connected with the driving gear 6. In this embodiment, the first connecting portion 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 mesh with each other. After the driving gear 6 is inserted into the first connecting portion, the stopper 7 is installed at the end of the first crankshaft 1 to fix the driving gear 6 on the first crankshaft 1. The stopper 7 in this embodiment adopts a locking nut, which can be threadedly connected with 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, wherein 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 is arranged on the driven gear 9, the first boss 1101 extends circumferentially on the driven gear 9 with the axis of the driven gear 9 as the center, the second boss 1102 extends vertically on the first boss 1101 along the direction of the driven gear 9 toward the cooling component, 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] Exemplarily, in this embodiment, the second counterweight 11 includes two parts, the first part is circumferentially extended and arranged on the driven gear 9, and the overall shape is annular, and the second boss 1102 is a boss formed by the outer edge of the first boss 1101 extending toward the axial direction of the driven gear 9 along the direction of the cooling assembly, wherein the width of the second boss 1102 is smaller than the width of the first boss 1101 so that the second boss 1102 can be away from the balance shaft 8, so as to facilitate the installation of the cooling assembly. If the width of the first boss 1101 is insufficient, a part of the second boss 1102 can extend to the surface of the driven gear 9, but in the design, it cannot affect the matching relationship between the driving gear 6 meshing with it.

[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, thereby 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 disposed on the balance shaft 8 and is located at an 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 via the shaft sleeve 10, and a second counterweight 11 is arranged 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 second counterweight 11, and the timing sprocket 12 is arranged on the sleeve 10. In this embodiment, the timing sprocket 12 is arranged on the left side of the driven gear 9, and the second counterweight 11 is arranged on the right end face of the driven gear 9.

[0056] In this embodiment, the driven gear 9 and the timing sprocket 12 are integrated into the bushing 10. When connecting, it is only necessary to install the bushing 10 onto the balance shaft 8 to achieve the connection between the driven gear 9, the timing sprocket 12 and the fixed shaft 15. The bushing 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, and 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 connecting piece and make assembly more convenient.

[0059] It should also be noted that a plurality of weight-reducing holes are opened in the portion of the second counterweight block 11 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 the 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 passes 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, the fixed shaft 15 is rotatably connected to the piston rod 4, and when the crank arm 3 rotates, the piston rod 4 can reciprocate along the inside of the cylinder. The first avoidance opening 101 and the second avoidance opening 201 can make the entire crankshaft assembly more compact, the axis of the crankshaft is closer to the top, and the internal space occupied by the crankshaft assembly is reduced, thereby reducing the volume 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 arranged continuously, 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 located at the top dead center, the piston rod 4 is in a tilted state, and the tilting 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 tipping over, and may improve driving comfort.

[0065] The present invention 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 a more comfortable driving experience for the driver.

[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 familiar with 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still 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 one pair of crank arms, a piston rod is provided between the crank arms, the crank arms include a first counterweight, and the main shaft is provided with a driving gear; A transmission mechanism, the transmission mechanism comprising a balancing shaft and a driven gear, the driven gear meshing with the driving gear, a second counterweight block being arranged on the driven gear, and the second counterweight block 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 where the first crankshaft and the second crankshaft are close to each other, and the driving gear 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 matched 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 comprises 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 from the driven gear to 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 an 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 1, 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, the first crankshaft is provided with a first avoidance opening for avoiding the fixed shaft, and the second crankshaft is provided with a second avoidance opening for avoiding the fixed shaft.

9. The engine crankshaft and balance weight structure according to claim 1, characterized in that: The first counterweight block is circumferentially extended with the axis of the first crankshaft as the center, and 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: It comprises an engine crankshaft and a balancing weight structure as described in any one of claims 1 to 9.

Images