Crankshaft web for a crankshaft assembly of an internal combustion engine

Abstract

The present invention relates to a crankshaft web (110) for a crankshaft assembly (100) of an internal combustion engine (12). The crankshaft web (110) has a recess (150) configured to receive a connecting rod (160), and the recess (150) is arranged between a center (112) of the crankshaft web (110) and a peripheral end (114) on the crankshaft web (110). A first peripheral portion (120) extends between a first end (120A) and a second end (120B) and is arranged at a diametrically opposite end of the peripheral end (114). The first peripheral portion (120) is configured to offset the rotational mass of the connecting rod (160). A second peripheral portion (122) extends between a first end (120A) of the first peripheral portion (120) and the peripheral end (114). A third peripheral portion (124) extends between a second end (120B) of the first peripheral portion (120) and the peripheral end (114). Herein, the mass of the first peripheral portion (120) is greater than the mass of the second peripheral portion (122) or the third peripheral portion (124).

Description

Technical Field

[0001] The present invention relates to a crankshaft assembly for an internal combustion engine. Background Art

[0002] In conventional motor vehicles, especially saddle-type vehicles with single-cylinder internal combustion engines, the crankshaft assembly performs multiple functions. The first of these functions is to convert the reciprocating motion of the piston into rotational motion. In addition to this, the crankshaft assembly also performs the function of balancing the unbalanced rotating and reciprocating masses, as well as the function of balancing the unbalanced forces caused by the power stroke of the internal combustion engine.

[0003] Especially for the functions of balancing the unbalanced rotating masses and balancing the unbalanced forces due to the power stroke of the internal combustion engine, the mass and inertia of the crankshaft assembly play a vital role. If the inertia of the crankshaft is low, it will cause large fluctuations in the engine idle RPM. Such fluctuations in the idle RPM are called idle instability and are undesirable in the operation of the internal combustion engine. Idle instability causes severe jolts and vibrations at low speeds, forcing the rider to operate the vehicle at a higher RPM. On the contrary, if the mass of the crankshaft assembly is increased to increase the inertia, it will result in a heavier internal combustion engine, affecting fuel efficiency and the overall weight of the vehicle.

[0004] In conventional crankshaft assemblies, the crank web is configured in such a way that the mass is not evenly distributed throughout the crank web. The conventional configuration of the crank web is such that more mass is concentrated toward the center of the web and less mass is concentrated at the periphery of the web. As is well known, the moment of inertia of the disk is given by MR 2 / 2, where R is the effective radius of the disk. Due to the mass distribution in the conventional crank web configuration, the effective radius is lower and therefore the moment of inertia is lower.

[0005] Attempts have been made to increase the moment of inertia of the crank web by attaching additional components to the crank web, such as an inertia disc or a flywheel. This consists in the flywheel or inertia disc having a radially outer mass ring and a radially inner fastening flange for fastening to the crankshaft and / or the clutch. However, in such an arrangement, in order to increase the moment of inertia of the crankshaft assembly, a greater mass must be provided on the inertia disc or flywheel, which in turn leads to an increase in the weight of the crankshaft assembly and the engine. The addition of an inertia disc or flywheel also has a negative impact on the acceleration and fuel efficiency of the vehicle.

[0006] Therefore, there is a need in the art for a crankshaft web for a crankshaft assembly of an internal combustion engine that solves at least the above problems. Summary of the invention

[0007] On the one hand, the present invention relates to a crankshaft web for a crankshaft assembly of an internal combustion engine. The crankshaft web has a recess configured to receive a connecting rod, which is arranged between the center of the crankshaft web and a peripheral end on the crankshaft web. A first peripheral portion extends between a first end and a second end and is arranged at a diametrically opposite end of the peripheral end. The first peripheral portion is configured to offset the rotational mass of the connecting rod. The second peripheral portion extends between the first end and the peripheral end of the first peripheral portion. The third peripheral portion extends between the second end and the peripheral end of the first peripheral portion. In this article, the mass of the first peripheral portion is greater than the mass of the second peripheral portion or the third peripheral portion.

[0008] In one embodiment of the present invention, the first end of the first peripheral portion forms a first angle (θ) with respect to the transverse axis of the crankshaft web at the center of the crankshaft web. 1 ), and the second end of the first peripheral portion forms a second angle (θ) relative to the transverse axis of the crankshaft web at the center of the crankshaft web. 2 In one embodiment, the first angle (θ 1 ) and the second angle (θ 2 ) ranges from 20 degrees to 75 degrees.

[0009] In another embodiment of the present invention, the first peripheral portion, the second peripheral portion and the third peripheral portion protrude to form a first flange, a second flange and a third flange, respectively. In one embodiment, the first outer diameter is equal to the second outer diameter, and the first inner diameter is less than the second inner diameter, so that the first flange has a greater width than the second flange or the third flange. In an alternative embodiment, the first outer diameter is equal to the second outer diameter, and the first inner diameter is equal to the second inner diameter.

[0010] In another embodiment of the present invention, the second flange and the third flange have a second flange thickness. In one embodiment, the first flange thickness of the first flange is greater than the second flange thickness of the second flange or the third flange.

[0011] In another embodiment of the invention, the crankshaft web has a first inner wall extending from a first end of the first flange to the second flange, the first inner wall defining a first web area having a first web thickness, wherein at least a portion of the first inner wall abuts the recess.

[0012] In another embodiment of the invention, the crankshaft web has a second inner wall extending from the second end of the first flange to the third flange, the second inner wall defining a second web area having a second web thickness, wherein at least a portion of the second inner wall abuts the recess.

[0013] In another embodiment of the present invention, the second web thickness is equal to the first web thickness.

[0014] In another embodiment of the present invention, the first inner wall, the second inner wall and the first flange define a third web region having a third web thickness. In one embodiment, the third web thickness is greater than the first web thickness or the second web thickness.

[0015] In another embodiment of the present invention, the second web thickness or the first web thickness is less than the second flange thickness. In one embodiment, the third web thickness is greater than or equal to the second flange thickness. In one embodiment, the first flange thickness is greater than the third web thickness.

[0016] In one embodiment of the present invention, the recess is configured to receive the connecting rod through the needle shield and the crank pin.

[0017] In another embodiment of the present invention, the ratio of the moment of inertia to the mass of the crankshaft web is between 9 and 11.5 cm 2 in the range between. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Reference will be made to embodiments of the present invention, examples of which may be shown in the accompanying drawings. These figures are intended to be illustrative, rather than restrictive. Although the present invention has been generally described in the context of these embodiments, it should be understood that this is not meant to limit the scope of the present invention to these specific embodiments.

[0019] Figure 1 A right side view of an exemplary motor vehicle is shown in accordance with one embodiment of the present invention.

[0020] Figure 2 An exploded view of a crankshaft assembly according to one embodiment of the present invention is shown.

[0021] Figure 3A A side view of a crankshaft assembly according to one embodiment of the present invention is shown.

[0022] Figure 3B A front view of a crankshaft assembly according to one embodiment of the present invention is shown.

[0023] Figure 4 A front view of a crankshaft web of a crankshaft assembly according to one embodiment of the present invention is shown.

[0024] Figure 5 A perspective view of a crankshaft web of a crankshaft assembly according to one embodiment of the present invention is shown.

[0025] Fig. 6A A cross-sectional view along section LL of a crankshaft web according to one embodiment of the present invention is shown.

[0026] Figure 6BA front view of a crankshaft web according to an embodiment of the invention is shown, wherein section LL is shown. DETAILED DESCRIPTION

[0027] The present invention relates to a crankshaft assembly for an internal combustion engine. More particularly, the present invention relates to a crankshaft web for a crankshaft assembly for an internal combustion engine.

[0028] Figure 1 An exemplary motor vehicle 10 according to one embodiment of the present invention is shown. The motor vehicle 10 includes an internal combustion engine 12 disposed vertically. Preferably, the internal combustion engine 12 is a single-cylinder type internal combustion engine. The motor vehicle 10 includes a front wheel 14, a rear wheel 16, a frame member, a seat assembly 18, and a fuel tank 20. The frame member includes a head pipe 22, a main pipe 24, a down pipe (not shown), and a seat rail (not shown). The head pipe 22 supports a steering shaft (not shown) and two telescopic front suspensions 26 (only one is shown) attached to the steering shaft by a lower bracket (not shown). The two telescopic front suspensions 26 support the front wheel 14. The upper portion of the front wheel 14 is covered by a front fender 28, which is mounted to the lower portion of the telescopic front suspension 26 at the end of the steering shaft. The handlebar 30 is fixed to the upper bracket (not shown) and can be rotated to both sides. A headlight 32, a visor (not shown), and an instrument cluster (not shown) are arranged at the upper portion of the head pipe 22. The frame member includes a down tube (not shown) that can be located at the front of the internal combustion engine 12 and extends obliquely downward from the head tube 22. The main tube 24 of the frame member is located above the internal combustion engine 12 and extends rearward from the head tube 22. The internal combustion engine 12 is mounted at the front of the down tube, and the rear of the internal combustion engine 12 is mounted at the rear portion of the main tube 24. In one embodiment, the internal combustion engine 12 is mounted vertically, wherein the cylinder block extends vertically above the crankcase. In an alternative embodiment, the internal combustion engine 12 is mounted horizontally (not shown), wherein the cylinder block extends horizontally forward from the crankcase. In one embodiment, the cylinder block is disposed behind the down tube.

[0029] The fuel tank 20 is mounted on a horizontal portion of the main pipe 24. The seat rail is joined to the main pipe 24 and extends rearward to support the seat assembly 18. The rear swing arm 34 is connected to the frame member to swing vertically, and the rear wheel 16 is connected to the rear end of the rear swing arm 34. Typically, the rear swing arm 34 is supported by a single rear suspension 36 (as shown in the present embodiment) or by two suspensions on both sides of the motor vehicle 10. The taillight unit 33 is provided at the end of the motor vehicle 10 and at the rear of the seat assembly 18. A grab bar 35 is also provided at the rear of the seat rail. The rear wheel 16 arranged below the seat 18 is rotated by the driving force of the internal combustion engine 12, which is transmitted from the internal combustion engine 12 through a chain drive (not shown). The rear fender 38 is provided above the rear wheel 16.

[0030] Additionally, the vehicle's exhaust pipe 40 extends vertically downward from the engine 12 to a point, then extends beneath the engine 12, extending longitudinally along the length of the vehicle before terminating in a muffler 42. The muffler 42 is typically disposed proximate the rear wheels 16.

[0031] Figure 2 An exploded view of a crankshaft assembly 100 according to one embodiment of the present invention is shown. As shown, the crankshaft assembly 100 has at least one crankshaft web 110 connected to the crankshaft. Herein, the crankshaft web 110 is configured to receive a connecting rod 160. Because one end of the connecting rod 160 is connected to a piston (not shown), and the other end of the connecting rod 160 is received by the crankshaft web 110, thereby converting the reciprocating motion of the piston into the rotational motion of the crankshaft. Figure 2 In the illustrated embodiment, the crankshaft assembly 100 has a pair of crankshaft webs 110, wherein each of the crankshaft webs 110 is connected to a half of the crankshaft. Each of the crankshaft webs 110 has a recess 150 therein that is configured to receive a connecting rod 160 via a needle shield 152 and a crank pin 154. The crank pin 154 and the needle shield 152 help convert the reciprocating motion of the piston into the rotational motion of the crankshaft web 110, and thus the crankshaft assembly 100. During the rotation of the crankshaft web 110, the connecting rod 160 has a reciprocating mass that reciprocates with the piston and a rotating mass that rotates with the crankshaft web 110.

[0032] Figure 3A A side view of a crankshaft assembly 100 according to one embodiment of the present invention is shown, and Figure 3B 1 shows a front view of the crankshaft assembly 100. Figure 3B As shown, a recess 150 on the crankshaft web 110 for receiving the connecting rod 160 is disposed between the center 112 of the crankshaft web 110 and the peripheral end 114 of the crankshaft web 110. In one embodiment, the recess 150 is a circular recess. In addition, the crankshaft web 110 has a first peripheral portion 120 extending between a first end 120A and a second end 120B. In this article, the first peripheral portion 120 is disposed at the diametrically opposite end of the peripheral end 114. The first peripheral portion 120 is positioned at the diametrically opposite end of the peripheral end 114 so that the first peripheral portion 120 is configured to offset and balance the rotating mass of the connecting rod 160.

[0033] like Figure 3BAs further shown, the crankshaft web 110 also has a second peripheral portion 122 extending between the first end 120A of the first peripheral portion 120 and the peripheral end 114. The crankshaft web 110 also has a third peripheral portion 124 extending between the second end 120B of the first peripheral portion 120 and the peripheral end 114. Herein, the crankshaft web 110 is configured in a manner that the mass of the first peripheral portion 120 is greater than the mass of the second peripheral portion 122 or the third peripheral portion 124. First, such a configuration of the crankshaft web 110 ensures that the higher mass of the first peripheral portion 120 can effectively offset and balance the rotating mass of the connecting rod 160. Second, the configuration of the crankshaft web 110 ensures that the mass of the crankshaft web 110 is concentrated toward the periphery of the crankshaft web 110.

[0034] The effect of concentrating mass toward the periphery of the crankshaft web 110 is that the moment of inertia of the crankshaft web 110 increases. For example, if the crankshaft web 110 has the shape of a disk, the moment of inertia about the center axis of the disk is calculated as MR 2 / 2, where M represents the mass of the disk and R represents the effective radius of gyration of the disk around the central axis of the disk. The effect of mass concentration toward the periphery of the crankshaft web 110 by means of the first peripheral portion 120, the second peripheral portion 122 and the third peripheral portion 124 results in an increase in the effective radius of the crankshaft web 110, thereby increasing the moment of inertia of the crankshaft web 110.

[0035] Figure 4 FIG. 2 shows a front view of a crankshaft web 110 according to one embodiment of the present invention. Figure 4 As shown, the first end 120A of the first peripheral portion 120 forms a first angle (θ) with respect to the transverse axis (XX′) of the crankshaft web 110 at the center 112 of the crankshaft web 110. 1 In addition, the second end 120B of the first peripheral portion 120 forms a second angle (θ ) with respect to the transverse axis (XX′) of the crankshaft web 110 at the center 112 of the crankshaft web 110 . 2 In an embodiment of the present invention, the first angle (θ 1 ) and the second angle (θ 2 ) ranges from 20 degrees to 75 degrees.

[0036] Figure 5 FIG. 1 shows a perspective view of a crankshaft web 110 according to one embodiment of the present invention. Figure 5 As shown, in order to facilitate mass concentration on the periphery of the crankshaft web 110, the first peripheral portion 120, the second peripheral portion 122 and the third peripheral portion 124 protrude to form a first flange 120', a second flange 122' and a third flange 124' respectively. Figure 5 As further shown, the first flange 120' has a first inner diameter (ID1 ) and the first outer diameter (OD 1 ), the second flange 122' and the third flange 124' have a second inner diameter (ID 2 ) and the second outer diameter (OD 2 In this article, the first outer diameter (OD 1 ) is equal to the second outer diameter (OD 2 ), and the first inner diameter (ID 1 ) is smaller than the second inner diameter (ID 2 ). Therefore, the first flange 120' has a larger width than the second flange 122' or the third flange 124'. The first flange 120' having a larger width than the second flange 122' or the third flange 124' results in the mass of the first peripheral portion 120 being greater than the mass of the second peripheral portion 122 or the third peripheral portion 124. In an alternative embodiment of the present invention, the first outer diameter (OD 1 ) is equal to the second outer diameter (OD 2 ), and the first inner diameter (ID 1 ) is equal to the second inner diameter (ID 2 ).

[0037] Fig. 6A shows a side cross-sectional view along section LL of the crankshaft web 110 of the crankshaft assembly 100, and Figure 6B 1 shows a front view of the crankshaft web 110 in which section LL is shown. Fig. 6A As shown, the first flange 120' has a first flange thickness (t f1 ), and the second flange 122' and the third flange 124' have a second flange thickness (t f2 In one embodiment, the first flange thickness (t f1 ) is greater than the second flange thickness (t f2 This further promotes that the mass of the first peripheral portion 120 is greater than the mass of the second peripheral portion 122 or the third peripheral portion 124.

[0038] like Figure 6B As further shown, the crankshaft web 110 also has a first inner wall 132 extending from the first end 120A of the first flange 120' to the second flange 122'. The first inner wall 132 defines a first web region 142. The first web region 142 has a first web thickness (t w1 ).like Figure 6BAs shown, at least a portion of the first inner wall 132 abuts the recess 150. Similarly, the crankshaft web 110 has a second inner wall 134 extending from the second end 120B of the first flange 120' to the third flange 124'. The second inner wall 134 defines a second web region 144. The second web region 144 has a second web thickness (t w2 ).like Figure 6B As shown, at least a portion of the second inner wall 134 is adjacent to the recess 150. Fig. 6A As shown in the embodiment shown, the second web thickness (t w2 ) is equal to the first web thickness (t w1 ), that is, the thickness of the first web region 142 and the second web region 144 are equal.

[0039] like Figure 6B As further shown, the first inner wall 132, the second inner wall 134 and the first flange 120' of the crankshaft web 110 define a third web thickness (t w3 ) of the third web region 146. In addition, in one embodiment, the third web thickness (t w3 ) is greater than the first web thickness (t w1 ) or the second web thickness (t w2 ), that is, the thickness of the third web region 146 is greater than the thickness of the first web region 142 or the second web region 144.

[0040] Fig. 6A It is further shown that the second web thickness (t w2 ) or the first web thickness (t w1 ) is less than the second flange thickness (t f2 In addition, the third web thickness (t w3 ) is greater than or equal to the second flange thickness (t f2 ). In addition, the first flange thickness (t f1 ) is greater than the third web thickness (t w3 ). The configuration of the crankshaft web 110, i.e., the aforementioned interrelationship of the thicknesses of the first flange 120', the second flange 122', the third flange 124', the first web region 142, the second web region 144, and the third web region 146, results in a mass distribution of the crankshaft web 110 such that the effective radius of the crankshaft web 110 increases. The increase in the effective radius results in an increase in the moment of inertia of the crankshaft web 110 without necessarily increasing the mass of the crankshaft web 110. In an embodiment of the present invention, the ratio of the moment of inertia to the mass of the crankshaft web 110 is between 9 and 11.5 cm 2 in the range between.

[0041] Advantageously, the configuration of the crankshaft web of the present invention increases the moment of inertia of the crankshaft assembly without necessarily increasing the mass of the crankshaft assembly. The moment of inertia of the crankshaft assembly is increased. The high moment of inertia of the crankshaft assembly reduces the level of idle RPM fluctuations.

[0042] Furthermore, the higher mass of the first peripheral portion ensures that the rotating mass of the connecting rod is adequately balanced, thereby reducing torsional vibrations in the crankshaft assembly.

[0043] Furthermore, the present invention ensures that the mass of the crankshaft assembly is not increased by increasing the moment of inertia of the crankshaft assembly, thereby not increasing the mass of the engine, and thus providing better fuel efficiency and acceleration.

[0044] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A crankshaft web (110) for a crankshaft assembly (100) of an internal combustion engine (12), the crankshaft web (110) include: a recess (150) configured to receive a connecting rod (160), the recess (150) being disposed between a center (112) of the crankshaft web (110) and a peripheral end (114) on the crankshaft web (110); a first peripheral portion (120) extending between the first end (120A) and the second end (120B), the first peripheral portion (120) being disposed at a diametrically opposite end of the peripheral end (114) and configured to offset the rotational mass of the connecting rod (160); a second peripheral portion (122) extending between the first end (120A) and the peripheral end (114) of the first peripheral portion (120); and a third peripheral portion (124) extending between the second end (120B) of the first peripheral portion (120) and the peripheral end (114); wherein the mass of the first peripheral portion (120) is greater than the mass of the second peripheral portion (122) or the third peripheral portion (124); and The first peripheral portion (120), the second peripheral portion (122) and the third peripheral portion (124) protrude to form a first flange (120'), a second flange (122') and a third flange (124'), respectively.

2. The crankshaft web (110) according to claim 1, wherein the first end (120A) of the first peripheral portion (120) forms a first angle (θ) with respect to a transverse axis (XX') of the crankshaft web (110) at the center (112) of the crankshaft web (110). 1 ), and the second end (120B) of the first peripheral portion (120) forms a second angle (θ) with respect to the transverse axis (XX') of the crankshaft web (110) at the center (112) of the crankshaft web (110). 2 ).

3. The crankshaft web (110) according to claim 2, wherein the first angle (θ 1 ) and the second angle (θ 2 ) ranges from 20 degrees to 75 degrees.

4. The crankshaft web (110) according to claim 1, wherein the first flange (120') has a first inner diameter (ID 1 ) and the first outer diameter (OD 1 ), and the second flange (122') and the third flange (124') have a second inner diameter (ID 2 ) and the second outer diameter (OD 2 ).

5. The crankshaft web (110) of claim 4, wherein the first outer diameter (OD 1 ) is equal to the second outer diameter (OD 2 ), and the first inner diameter (ID 1 ) is smaller than the second inner diameter (ID 2 ), so the first flange (120') has a larger width than the second flange (122') or the third flange (124').

6. The crankshaft web (110) of claim 4, wherein the first outer diameter (OD 1 ) is equal to the second outer diameter (OD 2 ), and the first inner diameter (ID 1 ) is equal to the second inner diameter (ID 2 ).

7. The crankshaft web (110) of claim 1, wherein the second flange (122') and the third flange (124') have a second flange thickness (t f2 ).

8. The crankshaft web (110) according to claim 7, wherein the first flange thickness (t f1 ) is greater than the second flange thickness (t f2 ).

9. The crankshaft web (110) of claim 8, comprising a first inner wall (132) extending from the first end (120A) of the first flange (120') to the second flange (122'), the first inner wall (132) defining a first web thickness (t w1 ) of a first web region (142), wherein at least a portion of the first inner wall (132) is adjacent to the recess (150).

10. The crankshaft web (110) of claim 9, comprising a second inner wall (134) extending from the second end (120B) of the first flange (120') to the third flange (124'), the second inner wall (134) defining a second web thickness (t w2 ) of the second web region (144), wherein at least a portion of the second inner wall (134) is adjacent to the recess (150).

11. The crankshaft web (110) according to claim 10, wherein the second web thickness (t w2 ) is equal to the first web thickness (t w1 ).

12. The crankshaft web (110) of claim 10, wherein the first inner wall (132), the second inner wall (134), and the first flange (120') define a third web thickness (t w3 ) of the third web region (146).

13. The crankshaft web (110) according to claim 12, wherein the third web thickness (t w3 ) is greater than the first web thickness (t w1 ) or the second web thickness (t w2 ).

14. The crankshaft web (110) according to claim 11, wherein the second web thickness (t w2 ) or the first web thickness (t w1 ) is less than the second flange thickness (t f2 ).

15. The crankshaft web (110) according to claim 12, wherein the third web thickness (t w3 ) is greater than or equal to the second flange thickness (t f2 ).

16. The crankshaft web (110) according to claim 12, wherein the first flange thickness (t f1 ) is greater than the third web thickness (t w3 ).

17. The crankshaft web (110) of claim 1, wherein the recess (150) is configured to receive the connecting rod (160) through a needle shield (152) and a crank pin (154).

18. The crankshaft web (110) of claim 1, wherein the ratio of the moment of inertia to mass of the crankshaft web (110) is within 9 cm 2 Up to 11.5cm 2 in the range between.

Images