JP2020153459A - Pulley - Google Patents

Abstract

To inhibit transmission of a variable load from a pulley to a shaft effectively.SOLUTION: A pulley 60 provided at a shaft 30 includes: a pulley body part 61 around which a belt B is wound; and a connection mechanism 62 connecting the pulley body part 61 to an end part 35 of the shaft 30 in a manner that the pulley body part 61 can swing around a shaft 64 perpendicular to an axial direction of the shaft 30 and having elastic members 66, 67 which can elastically deform to absorb a variable load transmitted from the pulley 60 to the shaft 30 in conjunction with rotation.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to pulleys, and more particularly to crank pulleys provided on the crankshaft of an engine.

Generally, at the end of the crankshaft of an engine, a crank pulley that transmits power to auxiliary machinery such as an alternator, a pump, and a compressor via an endless belt is provided.

In this type of crank pulley, a damper device that reduces the torsional vibration of the crankshaft by absorbing the rotational fluctuation of the engine may be provided (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-314450

By the way, a bending load due to the tension of the endless belt wound around the crank pulley acts on the crankshaft. In addition, a gyro moment or the like caused by the mass of the damper device, the crank pulley, or the like also acts on the crankshaft as it rotates. Therefore, when the crank pulley rotates integrally with the crankshaft, fluctuating stress (for example, periodic fluctuation of bending stress) repeatedly acts on, for example, the fillet portion of the crankshaft, and the life of the crankshaft is extended. May have an impact.

The technique of the present disclosure aims to effectively suppress the transmission of variable loads (forces and torques) from the pulley to the shaft.

The technique of the present disclosure is a pulley provided on a shaft, in which a pulley main body around which a belt is wound and the pulley main body are shaken at an end of the shaft about an axis orthogonal to the axial direction of the shaft. It is characterized by including a connecting mechanism having an elastic member that can be movably connected and that can be absorbed by elastically deforming a fluctuating load transmitted from the pulley to the shaft with rotation.

Further, the pulley main body is provided with a through hole through which the shaft is inserted in the axial direction to project the end of the shaft, and the connecting mechanism allows the pulley main body to be inserted through the through hole. It is preferable that the shaft is swingably connected to the end of the protruding shaft.

Further, the shaft is a crankshaft of an engine having a plurality of cylinders, and among the plurality of cylinders, the piston of the cylinder closest to the pulley main body is located at the top dead center, and the cylinder is in the axial direction of the cylinder. On the other hand, it is preferable that the shaft of the connecting mechanism is provided so as to be orthogonal to each other in the axial direction of the crankshaft.

Further, the connecting mechanism includes a pin member as the shaft whose axial center is orthogonal to the axial direction of the shaft, a pin boss portion that supports the pin member at the end portion of the shaft, and a pulley main body portion. A yoke portion having a pair of arm portions that rotatably support the pin member is provided on one side surface, and the elastic member is formed by a spring interposed between the pulley main body portion and the shaft. It is preferably formed.

Further, the connecting mechanism has a first axis as the axis whose axial center is orthogonal to the axial direction of the shaft, and the axial center thereof is orthogonal to the axial direction of the shaft and is orthogonal to the first axis. A spider having a second shaft, a first yoke portion having a pair of arm portions that rotatably support the first shaft at the end portion of the shaft, and the second shaft portion on one side surface of the pulley body portion. A second yoke portion having a pair of arm portions that rotatably support the pulley is provided, and the elastic member is formed by a spring interposed between the pulley main body portion and the shaft. Is preferable.

According to the technique of the present disclosure, it is possible to effectively suppress the transmission of the fluctuating load from the pulley to the shaft.

It is a schematic partial sectional view of the engine provided with the crank pulley which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the crank pulley which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the modification of the crank pulley which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the crank pulley which concerns on 2nd Embodiment. It is a schematic cross-sectional view which shows the crank pulley which concerns on 3rd Embodiment. It is a schematic cross-sectional view which shows the crank pulley which concerns on 4th Embodiment. It is a schematic cross-sectional view which shows the crank pulley which concerns on another embodiment.

Hereinafter, the pulley according to the present embodiment will be described with reference to the accompanying drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

[First Embodiment]
FIG. 1 is a schematic partial cross-sectional view of an engine 10 including a crank pulley 60 according to the first embodiment.

As shown in FIG. 1, the engine 10 is, for example, an in-line 4-cylinder engine, and the engine main body 11 having a head cover 12, a cylinder head 13, a cylinder block 14, a crankcase 15, and an oil pan 16 in this order from the upper side. It has. The engine 10 is not limited to the in-line 4-cylinder engine shown in the illustrated example, and may be an in-line multi-cylinder engine other than the 4-cylinder engine, a V-type multi-cylinder engine, a horizontally opposed multi-cylinder engine, or a single-cylinder engine.

The cylinder block 14 is provided with a plurality of cylinders C1 to C4. Further, pistons P1 to P4 are housed in the cylinders C1 to C4 so as to be reciprocally movable. A small end portion of the connecting rod 22 is swingably connected to the pistons P1 to P4 via a piston pin 21. The combustion chamber is partitioned by the top surfaces of the pistons P1 to P4, the inner peripheral surfaces of the cylinders C1 to C4, and the lower surface of the cylinder head 13.

The cylinder head 13 is provided with injectors J1 to J4 for directly injecting fuel into the combustion chamber. Further, the cylinder head 13 is provided with an intake port (not shown) for introducing fresh air into the combustion chamber and an exhaust port (not shown) for drawing exhaust gas from the combustion chamber. The engine 10 is not limited to the direct injection engine shown in the illustrated example, and may be a premixed engine.

The engine 10 includes a crankshaft 30 rotatably supported between the cylinder block 14 and the crankcase 15.

More specifically, the crankshaft 30 is supported by a plurality of crankpins 31 to which connecting rods 22 are swingably connected to each other, and a bearing or the like (not shown) between the cylinder block 14 and the crankcase 15. A crank journal 32, a plurality of crank webs 33 connecting each crank pin 31 and each crank journal 32, and a plurality of counter weights 34 facing the crank web 33 with the rotation axis of the crankshaft 30 interposed therebetween. Is equipped with.

When the pistons P1 to P4 reciprocate in the cylinders C1 to C4 due to the explosive force in the combustion chamber, this reciprocating motion is transmitted from the connecting rod 22 to the crank pin 31 and converted into a rotary motion, and the crankshaft 30 moves the crank journal 32. It is designed to rotate around the axis.

A crank pulley 60 that transmits the rotational power of the engine 10 to an auxiliary machine 300 such as an alternator, a pump, and a compressor is provided at the starting end portion 35 (end portion) of the crankshaft 30 so as to be integrally rotatable. Specifically, the endless belt B is wound around the crank pulley 60 and the driven pulley 310 of the auxiliary machine 300, and the rotational power of the engine 10 is driven by the crankshaft 30, the crank pulley 60, the endless belt B, and the driven belt B. It is transmitted to the auxiliary machine 300 via the pulley 310. The number of endless belts B wound around the crank pulley 60 is not limited to one in the illustrated example, and may be a plurality of belts depending on the number of auxiliary machines 300, the arrangement layout, and the like.

Hereinafter, the details of the crank pulley 60 according to the first embodiment will be described.

FIG. 2 is a schematic cross-sectional view of the crank pulley 60 according to the first embodiment, and FIGS. (A) and (B) show states in which the rotation angles of the crankshaft 30 differ by 90 degrees.

As shown in FIGS. 2A and 2B, the crank pulley 60 of the first embodiment has a substantially bottomed cylindrical pulley main body 61 and a pulley main body 61 at the front end of a crankshaft 30 starting end 35. It is provided with a connecting mechanism 62 that is swingably connected to the surface.

A plurality of belt grooves 61B for winding the endless belt B are provided on the outer peripheral portion 61A of the pulley main body 61. Further, a damper mass 61D is provided on the outer peripheral portion 61A of the pulley main body portion 61 via a damper rubber 61C.

The connecting mechanism 62 includes a pin boss portion 63, a pin member 64, a yoke portion 65, and a pair of springs 66 and 67 as elastic members (see FIG. 2A).

The pin boss portion 63 is provided so as to project from the rear side surface of the pulley main body portion 61 toward the start end portion 35 (rear) of the crankshaft 30 with a predetermined length in the axial direction. The pin member 64 is arranged so that its axial center is orthogonal to the axial direction of the crankshaft 30 (including the axial direction of the crankpin 31 shown in FIG. 1). The pin member 64 is preferably supported by a pin boss portion 63 at a substantially intermediate position in the axial direction thereof.

The yoke portion 65 projects from the front end surface of the start end portion 35 of the crankshaft 30 toward the pulley main body portion 61 (front) by a predetermined length in the axial direction, and is separated from each other by a pair of arm portions 65A, 65B ( (See FIG. 2B). Both ends of the pin member 64 protruding from the pin boss portion 63 are rotatably supported on the pair of arm portions 65A and 65B, respectively.

That is, the pulley main body 61 can rotate integrally with the front end surface of the start end 35 of the crankshaft 30 in the circumferential direction via the connecting mechanism 62, and is centered on the pin member 64 orthogonal to the axis of the crankshaft 30. They are connected so as to be swingable in two directions.

The arrangement relationship between the pin boss portion 63 and the yoke portion 65 is not limited to the illustrated example, and the pin boss portion 63 is arranged by replacing the front end surface of the start end portion 35 of the crankshaft 30 and the yoke portion 65 with the pulley main body portion 61. You may.

The pair of springs 66 and 67 are interposed between the front end surface of the start end portion 35 and the rear side surface of the pulley main body 61 in a compressed state at two locations in the direction orthogonal to the axis of the pin member 64, respectively. There is. The pair of springs 66 and 67 are attached so that the side surfaces of the pulley main body 61 are balanced so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state.

A larger number of springs 66, 67 than in the illustrated example may be arranged at predetermined intervals in the circumferential direction. Alternatively, as shown in FIG. 3, one spring 66 may be arranged so as to be wound around the pin boss portion 63 and the yoke portion 65. However, in any of these cases, it is desirable to balance the side surface of the pulley body 61 so that it is orthogonal to the axial direction of the crankshaft 30 in a stationary state.

In the present embodiment, the pin member 64 supports the axis (or the pin member 64) when the piston P1 (see FIG. 1) of the cylinder C1 closest to the crank pulley 60 is located near the compression top dead point. The arm portions 65A and 65B of the yoke portion 65 are opposed to each other) so as to be substantially orthogonal to the cylindrical axial direction of the cylinder C1 (reciprocating movement direction of the piston P1) in the axial view of the crankshaft 30, in other words, the piston P1. The arrangement direction of the pair of springs 66, 67 facing each other across the axial center of the pin member 64 is substantially the same as the axial direction of the cylinder C1 in the axial view of the crankshaft 30. It is provided.

Here, the rigidity of the springs 66 and 67 is caused by the tension of the endless belt B and the mass of the damper mass 61D and the like with rotation, and the rigidity of the springs 66 and 67 is mainly from the pulley main body 61 to the crankshaft 30 mainly in the fillet (reference numeral A in FIG. It is desirable to set the rigidity so that the variable load, the gyro moment, the centrifugal force, etc. transmitted to the boundary portion between the crank pin 31 and the crank web 33 (shown) can be effectively reduced. Further, it is desirable that the springs 66 and 67 give an initial load at the time of mounting so that the tension is always transmitted to the crankshaft 30 and the pulley main body 61 even during rotation.

According to the crank pulley 60 according to the first embodiment described in detail above, the pulley main body 61 is swingably connected to the start end 35 of the crankshaft 30 via the connecting mechanism 62, and the pulley main body 61 and the crank Spring 66, 67 capable of absorbing a bending load by elastically deforming is provided between the shaft 30 and the starting end portion 35. As a result, it is effective that the fluctuating load caused by the tension of the endless belt B and the gyro moment caused by the mass of the damper mass 61D and the pulley body 61 act mainly on the fillet portion of the crankshaft 30. It becomes possible to deter. Further, by reducing the fluctuating stress based on the fluctuating load, it is possible to suppress fatigue fracture of the crankshaft 30, and it is possible to effectively extend the life of the crankshaft 30.

[Second Embodiment]
FIG. 4 is a schematic cross-sectional view of the crank pulley 70 according to the second embodiment, and FIGS. 4A and 4B show a state in which the rotation angles of the crankshaft 30 differ by 90 degrees.

As shown in FIG. 4, in the crank pulley 70 of the second embodiment, a substantially bottomed cylindrical pulley main body 71 is placed on the front end surface of the starting end portion 35 of the crankshaft 30 via a universal joint 72 (an example of a connecting mechanism). It is a concatenation.

Specifically, the outer peripheral portion 71A of the pulley main body 71 is provided with a plurality of belt grooves 71B for winding the endless belt B as in the first embodiment. Further, a damper mass 71D is provided on the outer peripheral portion 71A of the pulley main body 71 via the damper rubber 71C.

The universal joint 72 is a pair of arm portions 73A, 73B that project from the front end surface of the start end portion 35 of the crankshaft 30 toward the pulley main body 71 side (front) by a predetermined length in the axial direction and are separated from each other. The first yoke portion 73 having (see FIG. 4B), the spider 74 having the first axis 74A and the second axis 74B orthogonal to each other, and the pulley main body 71 in the axial direction from the rear side surface to the rear. A second yoke portion 75 having a pair of arm portions 75A and 75B (see FIG. 4A) projecting to each other with a predetermined length and facing each other at a distance from each other is provided.

The spider 74 is arranged so that the axes of the first and second axes 74A and 74B are orthogonal to the axial direction of the crankshaft 30 (including the axial direction of the crankpin 31 shown in FIG. 1). Each of the arm portions 73A and 73B of the first yoke portion 73 rotatably supports both ends of the first shaft 74A of the spider 74. Each of the arm portions 75A and 75B of the second yoke portion 75 rotatably supports both ends of the second shaft 74B of the spider 74.

That is, the pulley main body 71 can rotate integrally with the front end surface of the starting end portion 35 of the crankshaft 30 via the universal joint 72 in the circumferential direction, and the two first and one orthogonal to the axial center of the crankshaft 30. The second shafts 74A and 74B are oscillatingly connected in four directions.

Similar to the first embodiment, the spring 76 is interposed between the front end surface of the start end portion 35 of the crankshaft 30 and the rear side surface of the pulley main body portion 71 in a compressed state. The spring 76 is preferably attached so that the side surface of the pulley body 71 is balanced so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state. The number of springs 76 is not limited to one, and a plurality of springs 76 may be arranged at a predetermined pitch in the circumferential direction. However, also in this case, it is desirable to balance the side surface of the pulley body 71 so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state.

In the present embodiment, the spider 74 pivotally supports the axis of the first shaft 74A (or the first shaft 74A) when the piston P1 of the cylinder C1 closest to the crank pulley 70 is located near the compression top dead point. The arm portions 73A and 73B of the first yoke portion 73 (opposing directions) are orthogonal to the cylinder axial direction of the cylinder C1 in the axial view of the crankshaft 30, and the piston P2 of the cylinder C2 which is second closest to the crank pulley 70 ( When the piston (piston whose phase is about 180 degrees different from that of the piston P1) is located near the compression top dead point, the axis of the second shaft 74B should be orthogonal to the cylinder axis direction of the cylinder C2 in the axial view of the crankshaft 30. It is provided in.

Here, the rigidity of the spring 76 is a variable load, a gyro moment, which is transmitted from the pulley main body 71 to the main fillet of the crankshaft 30 due to the tension of the endless belt B and the mass of the damper mass 71D due to rotation. It is desirable to set the rigidity so that the centrifugal force can be effectively reduced. Further, it is desirable that the spring 76 applies an initial load at the time of mounting so that the tension is always transmitted to the crankshaft 30 and the pulley main body 71 even during rotation.

According to the crank pulley 70 according to the second embodiment described in detail above, the pulley main body 71 is oscillatingly connected to the start end 35 of the crankshaft 30 via the universal joint 72, and the pulley main body 71 and the crank. A spring 76 capable of absorbing a bending load by elastically deforming is provided between the shaft 30 and the starting end portion 35. As a result, it is effective that the fluctuating load caused by the tension of the endless belt B and the gyro moment caused by the mass of the damper mass 71D and the pulley body 71 act mainly on the fillet part of the crankshaft 30. It becomes possible to deter. Further, by reducing the fluctuating stress based on the fluctuating load, it is possible to suppress fatigue fracture of the crankshaft 30, and it is possible to effectively extend the life of the crankshaft 30. Further, it is possible to reduce the noise caused by the rotation of the crankshaft 30 and the crank pulley 70.

[Third Embodiment]
FIG. 5 is a schematic cross-sectional view of the crank pulley 80 according to the third embodiment, and FIGS. 5A and 5B show a state in which the rotation angles of the crankshaft 30 differ by 90 degrees.

As shown in FIG. 5, in the crank pulley 80 of the third embodiment, the pulley main body 81 having a substantially bottomed cylindrical shape and the pulley main body 81 are swingably connected to the front end surface of the start end portion 35 of the crankshaft 30. It is provided with a connecting mechanism 82.

The pulley main body 81 closes the cylindrical outer peripheral portion 81A, the annular front flange portion 81E extending radially inward from the opening peripheral edge on the front end side of the outer peripheral portion 81A, and the opening on the rear end side of the outer peripheral portion 81A. It is provided with a rear side surface portion 81F.

A plurality of belt grooves 81B for winding the endless belt B are provided on the outer peripheral portion 81A of the pulley main body 81. Further, a damper mass 81D is provided on the outer peripheral portion 81A of the pulley main body 81 via the damper rubber 81C.

The rear side surface portion 81F of the pulley main body portion 81 is provided with a through hole 81G that penetrates the central portion thereof in the axial direction. The through hole 81G is inserted through the start end portion 35 of the crankshaft 30.

The connecting mechanism 82 includes a pin boss portion 83, a pin member 84, a yoke portion 85, and a spring 86 as an elastic member.

The pin boss portion 83 is provided so as to project forward from the front end surface of the start end portion 35 of the crankshaft 30 projecting from the through hole 81G with a predetermined length in the axial direction. The pin member 84 is arranged so that its axial center is orthogonal to the axial direction of the crankshaft 30 (including the axial direction of the crankpin 31 shown in FIG. 1). The pin member 84 is preferably supported by the pin boss portion 83 at a substantially intermediate position in the axial direction thereof.

The yoke portion 85 is a pair of arm portions 85A, 85B (see FIG. 5B) that project forward from the front flange portion 81E of the pulley body portion 81 in the axial direction by a predetermined length and are separated from each other. It has. Both ends of the pin member 84 protruding from the pin boss portion 83 are rotatably supported on the pair of arm portions 85A and 85B, respectively.

That is, the pulley main body 81 can rotate integrally with the front end surface of the start end 35 of the crankshaft 30 protruding from the through hole 81G in the circumferential direction via the connecting mechanism 82, and is orthogonal to the axial center of the crankshaft 30. The pin member 84 is oscillatingly connected in two directions.

The spring 86 is provided between the crankshaft 30 and the pulley main body 81. Specifically, of the starting end portion 35 of the crankshaft 30, a stepped portion 36 (or a stepped portion 36) having a front side surface facing the rear side surface portion 81F of the pulley main body portion 81 at a portion rearward of the through hole 81G. Flange) is provided. The spring 86 is interposed between the stepped portion 36 facing each other and the rear side surface portion 81F in a compressed state.

The spring 86 is preferably attached so that the rear side surface portion 81F of the pulley main body portion 81 is in a stationary state and is balanced so as to be orthogonal to the axial direction of the crankshaft 30. The number of springs 86 is not limited to one, and for example, a plurality of springs 86 may be arranged at a predetermined pitch in the circumferential direction. However, also in this case, it is desirable to balance the rear side surface portion 81F of the pulley main body portion 81 so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state.

In the present embodiment, the pin member 84 supports the axis (or the pin member 84) when the piston P1 (see FIG. 1) of the cylinder C1 closest to the crank pulley 80 is located near the compression top dead center. The arm portions 85A and 85B of the yoke portion 85 are provided so as to be substantially orthogonal to the cylindrical axial direction of the cylinder C1 (reciprocating movement direction of the piston P1) in the axial view of the crankshaft 30.

Here, the rigidity of the spring 86 is caused by the tension of the endless belt B and the mass of the damper mass 81D due to rotation, and the variable fruit tree and the gyro moment transmitted from the pulley main body 81 to the main fillet of the crankshaft 30. It is desirable to set the rigidity so that the centrifugal force can be effectively reduced. Further, it is desirable that the spring 86 applies an initial load at the time of mounting so that the tension is always transmitted to the crankshaft 30 and the pulley main body 81 even during rotation.

According to the crank pulley 80 according to the third embodiment described in detail above, the pulley main body 81 is swingably connected to the start end 35 of the crankshaft 30 via the connecting mechanism 82, and the pulley main body 81 and the crank A spring 86 capable of absorbing a bending load by elastically deforming is provided between the shaft 30 and the starting end portion 35. As a result, it is effective that the fluctuating load caused by the tension of the endless belt B and the gyro moment caused by the mass of the damper mass 81D and the pulley body 81 act mainly on the fillet portion of the crankshaft 30. It becomes possible to deter. Further, by reducing the fluctuating stress due to the fluctuating load, it is possible to suppress fatigue fracture of the crankshaft 30, and it is possible to effectively extend the life of the crankshaft 30. Further, it is possible to reduce the noise caused by the rotation of the crankshaft 30 and the crank pulley 70.

Further, by arranging the connecting mechanism 82 in front of the rear side surface portion 81F of the pulley main body 81 without arranging it between the engine 10 and the pulley main body 81, the pulley main body 81 is placed at the front end of the engine 10. It becomes possible to make them adjacent to each other, and the total length of the engine 10 in the crankshaft direction can be effectively shortened.

[Fourth Embodiment]
FIG. 6 is a schematic cross-sectional view of the crank pulley 90 according to the fourth embodiment, and FIGS. 6A and 6B show a state in which the rotation angles of the crankshaft 30 differ by 90 degrees.

As shown in FIG. 6, in the crank pulley 90 of the fourth embodiment, the substantially bottomed cylindrical pulley main body 91 and the pulley main body 91 are swingably connected to the front end surface of the start end 35 of the crankshaft 30. It is equipped with a universal joint 92.

The pulley main body 91 closes the cylindrical outer peripheral portion 91A, the annular front flange portion 91E extending radially inward from the opening peripheral edge on the front end side of the outer peripheral portion 91A, and the opening on the rear end side of the outer peripheral portion 91A. It is provided with a rear side surface portion 91F.

A plurality of belt grooves 91B for winding the endless belt B are provided on the outer peripheral portion 91A of the pulley main body portion 91. Further, a damper mass 91D is provided on the outer peripheral portion 91A of the pulley main body portion 91 via the damper rubber 91C.

The rear side surface portion 91F of the pulley main body portion 91 is provided with a through hole 91G that penetrates the central portion in the axial direction. The through hole 91G allows the start end portion 35 of the crankshaft 30 to pass through.

The universal joint 92 protrudes forward from the front end surface of the start end portion 35 of the crankshaft 30 by a predetermined length in the axial direction, and has a pair of arm portions that are separated from each other and face each other 93A, 93B (FIG. 6A). The first yoke portion 93 having (see), the spider 94 having the first shaft 94A and the second shaft 94B orthogonal to each other, and the spider 94 having the second shaft 94B, and the predetermined length in the axial direction from the front flange portion 91E of the pulley main body 91 toward the front. It is provided with a second yoke portion 95 having a pair of arm portions 95A and 95B (see FIG. 6B) that project from each other and face each other at a distance from each other.

The spider 94 is arranged so that the axes of the first and second axes 94A and 94B are orthogonal to the axial direction of the crankshaft 30 (including the axial direction of the crankpin 31 shown in FIG. 1). Each of the arm portions 93A and 93B of the first yoke portion 93 rotatably supports both ends of the first shaft 94A of the spider 94. Each of the arm portions 95A and 95B of the second yoke portion 95 rotatably supports both ends of the second shaft 94B of the spider 94.

That is, the pulley main body 91 can rotate integrally with the front end surface of the starting end portion 35 of the crankshaft 30 via the universal joint 92 in the circumferential direction, and the two first and one orthogonal to the axial center of the crankshaft 30. The second shafts 94A and 94B are oscillatingly connected in four directions.

Similar to the third embodiment, the spring 96 is interposed between the stepped portion 36 of the crankshaft 30 and the rear side surface portion 91F of the pulley main body portion 91 in a compressed state. The spring 96 is preferably attached so that the rear side surface portion 91F of the pulley main body portion 91 is in a stationary state and is balanced so as to be orthogonal to the axial direction of the crankshaft 30. The number of springs 96 is not limited to one, and for example, a plurality of springs 96 may be arranged at a predetermined pitch in the circumferential direction. However, also in this case, it is desirable to balance the rear side surface portion 91F of the pulley main body portion 91 so as to be orthogonal to the axial direction of the crankshaft 30 in a stationary state.

In the present embodiment, the spider 94 pivotally supports the axis of the first shaft 94A (or the first shaft 94A) when the piston P1 of the cylinder C1 closest to the crank pulley 90 is located near the compression top dead point. The arm portions 93A and 93B of the first yoke portion 93 (opposing directions) are orthogonal to the cylinder axial direction of the cylinder C1 in the axial view of the crankshaft 30, and the piston P2 of the cylinder C2 (second closest to the crank pulley 90) ( When the piston (piston whose phase is about 180 degrees different from that of the piston P1) is located near the compression top dead point, the axis of the second axis 94B should be orthogonal to the axial direction of the cylinder C2 in the axial view of the crankshaft 30. It is provided in.

Here, the rigidity of the spring 96 is a variable load, a gyro moment, which is transmitted from the pulley main body 91 to the main fillet of the crankshaft 30 due to the tension of the endless belt B and the mass of the damper mass 91D due to rotation. It is desirable to set the rigidity so that the centrifugal force can be effectively reduced. Further, it is desirable that the spring 96 applies an initial load at the time of mounting so that the tension is always transmitted to the crankshaft 30 and the pulley main body 91 even during rotation.

According to the crank pulley 90 according to the fourth embodiment described in detail above, the pulley main body 91 is oscillatingly connected to the start end 35 of the crankshaft 30 via a universal joint 92, and the pulley main body 91 and the crank A spring 96 capable of absorbing a bending load by elastically deforming is provided between the shaft 30 and the starting end portion 35. As a result, it is effective that the fluctuating load caused by the tension of the endless belt B and the gyro moment caused by the mass of the damper mass 91D and the pulley body 91 act mainly on the fillet portion of the crankshaft 30. It becomes possible to deter. Further, by reducing the fluctuating stress based on the fluctuating load, it is possible to suppress fatigue fracture of the crankshaft 30, and it is possible to effectively extend the life of the crankshaft 30.

Further, by arranging the universal joint 92 in front of the rear side surface portion 91F of the pulley main body 91 without arranging it between the engine 10 and the pulley main body 91, the pulley main body 91 is placed at the front end of the engine 10. It becomes possible to make them adjacent to each other, and the total length of the engine 10 in the crankshaft direction can be effectively shortened.

[Other]
It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the gist of the present disclosure.

For example, as shown in FIG. 7, the spring of the above embodiment may be replaced with another elastic member such as an elastically deformable mesh material 100 or an elastically deformable leaf spring.

Further, the scope of application of the present disclosure is not limited to the crank pulley provided on the crankshaft 30 of the engine 10, and can be widely applied to the rotating system of other devices.

10 Engine 11 Engine body 12 Head cover 13 Crankshaft 14 Crankcase block 15 Crankcase 16 Oil pan C1 to C4 Cylinder P1 to P4 Piston 21 Piston pin 22 Connecting rod 30 Crankshaft 31 Crankpin 32 Crankjour 33 Crankweb 34 Counterweight 35 Start end (end)
60, 70, 80, 90 Crank pulley (pulley)
61, 71, 81, 91 Pulley body 62, 82 Connecting mechanism 63, 83 Pin boss 64, 84 Pin member 65, 85 Yoke 72, 92 Universal joint (connecting mechanism)
73,93 1st yoke part 74,94 Spider 75,95 2nd yoke part 66,67,76,86,96 Spring (elastic member)
81G, 91G through hole

Claims (5)

A pulley provided on the shaft
The pulley body around which the belt is wrapped and
The pulley main body is swingably connected to the end of the shaft about an axis orthogonal to the axial direction of the shaft, and the variable load transmitted from the pulley to the shaft is elastically deformed with rotation. A pulley characterized by comprising a connecting mechanism having an elastic member that can be absorbed therein. The pulley body is provided with a through hole through which the shaft is inserted in the axial direction to project the end of the shaft.
The pulley according to claim 1, wherein the connecting mechanism oscillateably connects the pulley main body to the end of the shaft protruding from the through hole. The shaft is a crankshaft of an engine having a plurality of cylinders.
Among the plurality of cylinders, the shaft of the connecting mechanism is viewed in the axial direction of the crankshaft with respect to the cylinder axis direction of the cylinder in a state where the piston of the cylinder closest to the pulley main body is located at the top dead center. The pulley according to claim 1 or 2, which is provided so as to be orthogonal to each other. The connecting mechanism includes a pin member as the shaft whose axial center is orthogonal to the axial direction of the shaft, a pin boss portion that supports the pin member at the end portion of the shaft, and one side surface of the pulley body portion. It is provided with a yoke portion having a pair of arm portions that rotatably support the pin member.
The pulley according to any one of claims 1 to 3, wherein the elastic member is formed of a spring interposed between the pulley main body and the shaft. The connecting mechanism has a first axis as the axis whose axis is orthogonal to the axial direction of the shaft, and a second axis whose axis is orthogonal to the axial direction of the shaft and orthogonal to the first axis. A spider having a shaft, a first yoke portion having a pair of arm portions that rotatably support the first shaft at the end portion of the shaft, and the second shaft rotating on one side surface of the pulley main body portion. It is provided with a second yoke portion having a pair of arm portions that support the shaft as possible.
The pulley according to any one of claims 1 to 3, wherein the elastic member is formed of a spring interposed between the pulley main body and the shaft.

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