JPH05164191A - Varying torque reducing device - Google Patents

Abstract

PURPOSE:To provide a varying torque reducing device which can improve durability by reducing varying torque and alleviating the burden of a shaft or a bearing. CONSTITUTION:A main elliptical gear 10 is provided at a main shaft 6, and auxiliary elliptical gears 11 are connected to the main elliptical gear 10 transmittably. Flywheels 12 are fitted to these auxiliary elliptical gears 11, and flywheels 12 are rotated by means of the rotation of a crank shaft 4 or the main shaft 6 through the main elliptical gear 10 and auxiliary elliptical gears 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an engine such as a large diesel engine or a crank type press machine.
The present invention relates to a device for reducing fluctuating torque generated on a rotating shaft such as crank rotation.

[0002]

2. Description of the Related Art An internal combustion engine, a crank type press device or the like converts a reciprocating linear motion into a rotary motion, or vice versa.

In the case of an internal combustion engine, for example, the reciprocating motion of a piston is transmitted to a crankshaft via a connecting rod to rotate the crankshaft. In such a power transmission engine, when a reciprocating body such as a piston reaches the top dead center and the bottom dead center of the linear reciprocating motion, the torque applied to the crankshaft is reversed. Therefore, the torque of the crankshaft constantly fluctuates during its rotation.

In an internal combustion engine such as a diesel engine, in the case of a 4-cycle engine, torque fluctuations occur in the crankshaft at a ratio of the number of cylinders × a multiple of the number of revolutions × 1/2, and in the case of a 2-cycle engine. , Number of cylinders ×
Torque fluctuations occur at a rate that is a multiple of the number of revolutions.

Such torque fluctuations not only exert torque fluctuations on the driven side, but also cause torsional stress in the crankshaft or the main shaft driven by the crankshaft, which may lead to fatigue failure due to torsional vibration. The bearing is also severely burdened.

[0006] In order to absorb such torque fluctuations, conventionally, a means for providing a balance weight or a flywheel on a crankshaft or a main shaft driven by the crankshaft has been adopted.

The balance weight corrects the eccentricity of the crankshaft, and the flywheel reduces torque fluctuation due to a large inertial force, and these are effective for rotating the crankshaft or the main shaft at a constant speed.

[0008]

However, in the conventional case, the balance weight and the flywheel are directly attached to the crankshaft or the main shaft, and rotate integrally with the crankshaft or the main shaft. In order to reduce torque fluctuations, the flywheel's inertial force should be increased, and therefore a flywheel with a large weight should be used. Since the inertia is large, the output of the starter motor must be increased, and the responsiveness of speed change deteriorates.

Therefore, there is a limit to the size of the flywheel, and in the case of a large diesel engine or a crank type press device, the ability to absorb torque fluctuation is not sufficient and the crankshaft or main shaft is damaged or the bearing is damaged. I am worried about damage. There is also a problem that the torsional vibration causes noise such as a basket noise.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the fluctuating torque with a simple structure, reduce the load on the rotating shaft and the bearing, and improve the durability. It is intended to provide an improved fluctuating torque reducing device.

[0011]

In order to achieve the above object, the present invention provides a device for converting a linear reciprocating motion into a rotary motion, or a rotary ellipse gear in a rotating shaft of a device for converting a rotary motion into a linear reciprocating motion. Provided, the auxiliary elliptical gear is connected to the main elliptical gear for power transmission, the flywheel is attached to the auxiliary elliptical gear, and the flywheel is attached through the main elliptical gear and the auxiliary elliptical gear by the rotation of the rotary shaft. It is characterized by being rotated.

[0012]

According to the present invention, the rotation of the rotating shaft is transmitted to the flywheel via the main elliptical gear and the auxiliary elliptical gear, and thereby the flywheel is rotated, in which case the main elliptical gear and the auxiliary elliptical gear are used. The rotation speed of the power transmission structure changes during one rotation to change the rotation speed of the flywheel. Therefore, torque fluctuations occur in the flywheel, and this torque fluctuations can be balanced with the torque fluctuations generated on the rotary shaft side to cancel the torque fluctuations on the rotary shaft side.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS.

This embodiment shows a case where it is applied to a 4-cylinder 4-cycle diesel engine. In the figure, 1 indicates a cylinder block, 2 ... Pistons, and cylinders are omitted. Since the diesel engine of this embodiment has four cylinders, the four pistons 2 ... Are connected to the crankshaft 4 via connecting rods 3. Therefore, the linear reciprocating motion of the pistons 2 ... Is converted into the rotary motion of the crankshaft 4. The crankshaft 4 is rotatably supported by the cylinder block 1 by bearings 5, and a main shaft 6 is integrally provided on the crankshaft 4. Spindle 6
Are housed in a flywheel case 7, and the flywheel case 7 is connected to the cylinder block 1.

A pair of auxiliary shafts 8 and 8 are housed in the flywheel case 7, and these auxiliary shafts 8 and 8 are rotatably supported by the flywheel case 7 via bearings 9 ... These auxiliary shafts 8 and 8 are arranged parallel to the main shaft 6 and symmetrically with respect to the main shaft 6.

A main elliptical gear 10 is attached to the main shaft 6 so as to rotate integrally therewith. Further, auxiliary elliptical gears 11 and 11 that engage with the main elliptical gear 10 are attached to the auxiliary shafts 8 and 8, respectively. Further, flywheels 12, 12 are attached to the respective auxiliary shafts 8, 8.

As the main elliptical gear 10 and the auxiliary elliptical gear 11, those whose major axis and minor axis have the same size and the same curvature are used, and one short side tooth surface and the other long side tooth surface are mutually It is designed to mesh with each other.

Therefore, when the main shaft 6 rotates, the auxiliary shafts 8 and 8 rotate via the main elliptical gear 10 and the auxiliary elliptical gears 11 and 11, and therefore the flywheels 12 and 12 rotate. In this case, when the main shaft 6 makes one revolution, the auxiliary shafts 8, 8 and the flywheels 12, 12 also make one revolution. The operation of such a configuration will be described.

When the linear reciprocating motion of the pistons 2 ... Is converted into the rotary motion of the crankshaft 4 via the connecting rods 3 ,.
The main shaft 6 is rotated, and the rotation of the main shaft 6 causes the main elliptical gear 10 to rotate.
And via the auxiliary elliptical gears 11, 11 to the auxiliary shafts 8, 8 and thus the flywheels 12, 12 rotate.

The main elliptical gear 10 and the auxiliary elliptical gear 11 are engaged with each other such that the elliptical gears having the same shape are meshed with each other so that one short side tooth surface meshes with the other long side tooth surface. a)
As shown in the figure, in the region where the short side tooth surface of the main elliptical gear 10 meshes with the long side tooth surface of the auxiliary elliptical gear 11, the angular velocity of the auxiliary shaft 8 is relatively low as compared with the angular velocity of the main shaft 6, Therefore, the rotation speed of the auxiliary shaft 8 is relatively lower than the rotation speed of the main shaft 6.

On the other hand, as shown in FIG. 3B, in the region where the long side tooth surface of the main elliptical gear 10 meshes with the short side tooth surface of the auxiliary elliptical gear 11, the angular velocity of the main shaft 6 is increased. The angular velocity of the auxiliary shaft 8 is relatively faster than that of the main shaft 6, and thus the rotational speed of the auxiliary shaft 8 is relatively higher than that of the main shaft 6. Such speed fluctuations of the auxiliary shaft 8 occur during one rotation, and when the main shaft 6 rotates once at a constant speed, the auxiliary shaft 8
The rotational speed fluctuates twice during one rotation.

For this reason, the flywheels 12 and 12 also undergo two speed fluctuations during one rotation. Such speed fluctuations of the flywheels 12, 12 cause fluctuations in the torque of the flywheels 12, 12. That is, the torque of the flywheels 12, 12 increases when the rotation speed is high, and the torque of the flywheels 12, 12 decreases when the rotation speed is low.

If the phases of the torque fluctuations of the flywheels 12 and 12 and the torque fluctuations caused by the power transmitted from the pistons 2 to the crankshaft 4 are set so as to cancel each other, as shown in FIG. It is possible to reduce torque fluctuations that occur in the crankshaft 4 and the main shaft 6.

In particular, when two auxiliary wheels 8 are used and two flywheels 12, 12 generate torque fluctuations, a large rotational inertia can be secured, and large torque fluctuations due to speed changes can be obtained. You can

In the case of a 4-cylinder 4-cycle diesel engine, torque fluctuation occurs twice per revolution. That is, the torsional vibration is a sine wave having a frequency equal to the number of rotations × 2. On the other hand, if the main shaft 1 is rotated at a constant speed in synchronism with the rotation of the crankshaft 4, and the auxiliary shafts 8 are rotated at the same rotational speed, the flywheel 1
Two and twelve torque fluctuations occur in one rotation per rotation, and this torsional vibration becomes a sine wave having a frequency of rotation number × 2. Therefore, as shown in FIG. 4, the flywheel 1
The timing of the torque fluctuation occurring in
The torque fluctuations of the crankshaft 4 and the main shaft 4 can be canceled by balancing the torque fluctuations caused by the power transmitted from the crankshaft 4 to the crankshaft 4.

When the number of cylinders is other than 4, the frequency changes, so it is necessary to adjust the rotational speed of the crankshaft 4 and the rotational speeds of the flywheels 12 and 12 side. That is, in the case of a four-cycle engine, torque fluctuations occur in the crankshaft at a ratio of the number of cylinders × a multiple of the number of rotations × 1/2, and in the case of a two-cycle engine, torque fluctuations occur at a ratio of the number of cylinders × a number of rotations. Occurs. Therefore, as shown in FIG. 5, a transmission 15 is provided between the crankshaft 4 and the main shaft 6, and the transmission 15
The rotational speed of the main shaft 6 may be adjusted by. Number of cylinders and number of torque fluctuations (frequency) in one revolution generated on crankshaft 4
Table 1 shows the relationship between the gear ratio and the gear ratio of the transmission.

[0027]

[Table 1]

Therefore, for example, in the case of a 6-cylinder 4-cycle engine, as shown in Table 1, the ratio of the number of cylinders times the number of rotations times 1/2, that is, 3 times per crankshaft for one rotation.
Since the torque fluctuations occur once, if the speed of the crankshaft is increased by 1.5 times by the transmission to rotate the main shaft 6, the flywheels 12 and 12 can change the crankshaft speed based on the speed change. Torque fluctuations occur three times per rotation, which can cancel the torque fluctuations.

In each of the above embodiments, the main elliptical gear 10 is used.
The auxiliary elliptical gear 11 is directly meshed with each other to transmit the rotation. However, the main elliptical toothed wheel and the auxiliary elliptical toothed wheel may be arranged separately, and they may be connected by a toothed belt. Further, although two sets of auxiliary shafts 8, 8, auxiliary elliptical gears 11, 11 and flywheels 12, 12 are used, only one of them may be used.

Further, in the case of the above embodiment, the example applied to the engine has been described, so that the cause of the torque fluctuation is the driving force transmitted from the piston 2 to the crankshaft 4.
That is, the case of converting linear reciprocating motion into rotary motion has been described, but in the case of, for example, a crank type press device, the rotation of the motor is transmitted from the crankshaft to the plunger via the connecting rod, and therefore the rotary motion is It is adapted to be converted into a linear reciprocating motion, and even in such a power transmission system, torque fluctuations occur in the rotating shaft, so that it can be implemented in such a field.

[0031]

As described above, according to the present invention, when the rotation of the rotating shaft is transmitted to the flywheel via the main elliptical gear and the auxiliary elliptical gear, the rotation speed fluctuates during one rotation and the flywheel is rotated. Since the rotation speed changes, torque fluctuations occur in the flywheel, and the torque fluctuations cancel out the torque fluctuations that occur on the rotating shaft side. Therefore, the torque fluctuation can be reduced with a simple structure, and as a result, the durability of the rotating shaft and the bearing is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fluctuation torque reducing device applied to an engine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3A and 3B are diagrams for explaining the operation of the embodiment, in which FIG. 3A is a state where the rotation speed of the flywheel is low, and FIG. 3B is a diagram where the rotation speed of the flywheel is high.

FIG. 4 is a torque generation characteristic diagram for explaining the principle of canceling fluctuating torque.

FIG. 5 is a cross-sectional view of a variable torque reducing device showing another embodiment of the present invention.

[Explanation of symbols]

1 ... Cylinder block, 2 ... Piston, 3 ... Connecting rod, 4 ... Crank shaft, 6 ... Main shaft, 8 ... Auxiliary shaft, 10 ... Main elliptical gear, 11 ... Auxiliary elliptical gear, 12 ... Flywheel,
15 ... Transmission.

Claims (2)

[Claims] 1. A main elliptical gear is provided on a rotary shaft of a device for converting a linear reciprocating motion into a rotary motion, or a device for converting a rotary motion into a linear reciprocating motion, and an auxiliary elliptical gear can transmit power to the main elliptical gear. And a flywheel is attached to the auxiliary elliptical gear, and the flywheel is rotated by the rotation of the rotating shaft via the main elliptical gear and the auxiliary elliptical gear. .. 2. The rotation of the rotary shaft is transmitted to a main shaft via a transmission, and the transmission is arranged between the rotary shaft and the main shaft in accordance with the number of fluctuating torques generated during one rotation of the rotary shaft. A fluctuating torque reducing device, characterized in that the speed is changed and the rotational speeds of the main elliptical gear, the auxiliary elliptical gear and the flywheel are adjusted according to the fluctuating torque number.