KR830001282B1 - Compensation device for free moment generated from inertial force of internal combustion engine - Google Patents

Abstract

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Description

Compensation device for free moment generated from inertial force of internal combustion engine

1 is a longitudinal sectional view of a rear portion of a ship in which the apparatus of the present invention is installed.

2 is a cross-sectional view of another moment compensator or balancer that may be coupled to the device of the present invention.

The present invention relates to a device for compensating for free moment arising from the inertia force of an internal combustion engine acting as an internal combustion engine acting as a main engine or propulsion engine of a ship. It consists of at least one rotary unbalanced body, a drive motor coupled thereto, and a synchronizer for controlling the rpm and phase angle of the drive motor according to the rpm and phase angle of the internal combustion engine.

Due to the increase in fuel costs and deposits, the propulsion of ships tends to use relatively slow main engines, so-called long administrative engines, especially those with fewer cylinders, with 4-6 cylinders. Low rpms and engines are particularly economical due to improvements in engine and propulsion efficiency, and require less maintenance costs due to the reduction in the number of cylinders. In engines with a small number of cylinders, however, the vibrating bodies generate large free moments of the first and second order, which can cause dangerous or at least unpleasant vibrations in the ship's hull, gaining a full or partial balance of these moments. It is known to provide an engine with a moment compensator or balancer containing two counter-rotating unbalances that rotate at the same rpm as the main engine or at twice that rpm.

Named "Hull Girder Flexural Vertical Vibration" caused by the second imbalance moment of the diesel main engine, published in August 1978 by Ishikawajima-Haria Herri Industries Company Limited. From the Japanese publication, a device installed in a proper longitudinal space from a main engine is known. The device consists of a single rotary parallel body driven by an electric motor, and the shaft is installed across the hull at twice the rpm of the main engine. As it rotates, it generates a vibration perpendicular inertia force that can reduce the secondary moment of the engine.

The disadvantage of the last mentioned device is that the electric motor and the control device associated with it must be very large. The reason is that the motor power output is used to accelerate and decelerate the rotary unbalance in accordance with the acceleration and deceleration of the rpm of the engine when the main engine rotates at a constant rpm and as needed, even during engine acceleration and deceleration. This should be enough. Therefore, the ship's auxiliary power supply should be sized to produce a greater maximum output. Moreover, a reduction gear is required between the electric motor and the unbalance, which increases the cost and space required for the device.

These shortcomings are further exacerbated on ships with low rpm main tube, which means that for constant cylinder output and constant cylinder diameter, the moment of inertia and moment of inertia of each cylinder is almost independent of the process engine rotational speed, which results in a lower piston stroke. It can be seen from the experiment that this is because it increases and thus increases the vibrating body. Moreover, because the requirement for the inherent low irregularity of the device requires a large moment of inertia of the unbalance, the drive motor must be able to deliver a large output to change the number of revolutions of the object.

It is an object of the present invention to eliminate or at least reduce the above mentioned disadvantages, and an object of the present invention is that an unbalanced body is connected to a bi-displacement hydraulic pump driven by an internal combustion engine through a supply conduit and a return conduit. It is characterized by a double displacement hydraulic motor.

The present invention provides a fairly simple and inexpensive device. The large power consumption of the device of the present invention mentioned above is achieved only when the unbalance is accelerated or decelerated, while the relatively large power can be easily supplied by the main engine for a short period of time because the power consumption is much lower at constant rotational speed, This is required because the engine's nominal power is multiplied for a short period of time and thus conserves sufficient power. Therefore, there is a need to increase auxiliary engines and generators. The required phase synchronization between the main engine and the unbalance is facilitated by the conduit to which the pump and the drive motor of the unbalance driven by the main engine are directly connected. Hydraulic motors are much smaller than electric motors and are sized to provide the required output at low rpm, so they can be directly connected to an unbalanced body without intermediate deceleration control, thereby reducing the space taken up by the device. It is therefore possible to design a device for compensating for primary moments, especially in four-cylinder two-stroke engines. This is almost impossible in known devices driven by an electric motor for the required low rpm of the unbalance.

The hydraulic pump can be driven from the camshaft of the internal combustion engine. This has the advantage that the device can be easily added to existing propulsion as needed and that the main engine does not need to be specially designed to attach the pump.

In a preferred embodiment of the invention, the hydraulic motor is a radial plunger type motor which is directly connected to the rotary unbalance. This type of motor is well suited to supply high torque at low rpm of its output shaft. The drive motor can rotate at the same rpm as the internal combustion engine and is operably connected to other unbalances via a gear with a gear ratio of 1: 2. With this arrangement, two oscillating normal forces can be generated in the device to compensate for the primary and secondary moments.

The unbalanced axis of rotation may extend in the direction across the hull of the ship. As mentioned above, this facility can satisfactorily reduce the free moment of inertia in a main engine with only one unbalance for each moment.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 shows the rear end of the ship 1, in which the four-cylinder two-stroke diesel engine 2 is installed in the engine room of the ship for propulsion of the ship. The crankshaft 3 of the engine, shown schematically, is operatively connected to the propeller shaft 5 of the ship via a connecting device 4. FIG. 1 also shows the engine's regulator or camshaft 6 on which a cam (not shown) is fixed by operating the fuel pump and valve of the engine's cylinder. The camshaft 6 is driven from the crankshaft 3 via the chain transmission 7.

At the rear of the engine room, for example the steering engine room of the ship, a moment compensator or balancer 8 according to the invention is provided. As will be apparent from the following description, the balancer 8 generates a vertical force which compensates for the vibration caused by the ship's hull by the free moment of the engine 2. Providing the balancer 8 adjacent to the stern is advantageous for the form of large amplitude hull vibrations at this position.

The vibration force described above is generated by an unbalanced body 9 which is journaled in the housing of the balancer and fixed to the shaft 10 extending across the hull. The shaft 10 is driven directly from the output shaft 11 of the hydraulic motor 12, preferably of the radial plunger type motor. For the sake of clarity, FIG. 1 shows the motor 12 positioned in front of the balancer 8 and separated from the balancer 8, but this is usually installed with the balancer and the shafts 10, 11 are To be coaxial.

The cam shaft 6 is directly connected to a radial plunger type hydraulic pump 13, which is connected to the motor 12 by means of a waste hydraulic circuit having a supply conduit 14 and a return conduit 15. It is connected. The hydraulic circuit cannot, of course, have other components (not shown) such as tanks, pressurizers and suitable devices to compensate for hydraulic liquid leakage, thermal expansion and contraction of the liquid from the circuit, and the like.

The hydraulic circuit also includes an adjusting device to apply an accurate phase synchronization of the rotation of the pump 13 and the motor 12, which in FIG. 1 comprises a signal transmitter 16 and a transmitter 16 of the pump 13. Is schematically shown by the control or signal transmission line 17 from the motor to the motor 12.

It can be seen from the first road that the rpm of the unbalance 9 is equal to the rpm of the camshaft 6, and therefore the rpm of the crankshaft 3, and the balancer 8 goes to the engine 2. To generate the force to compensate the first moment. In engine installations where primarily the second moment is desired to be compensated, there is a similar device with a single unbalanced body (9) and a hydraulic circuit designed to drive the unbalanced drive motor at twice the rpm of the crankshaft of the main engine. Can be used.

2 shows a balancer in which one hydraulic pressure, drive motor and one hydraulic pump connected to the internal combustion engine can compensate for the primary and secondary moments. The balancer of FIG. 2 has a housing 21 installed with a hydraulic drive motor 22 relative to an output shaft 23 on which an unbalance 24 which rotates in the housing 21 is fixed. The shaft 23 supports the gear wheel 25, which is twice the size of the second gear wheel 26, the gear wheel 25 being journaled to the housing 21 and supporting the second unbalance 28. Meshes with the gear wheel 26 fixed to the shaft 27.

Since the hydraulic motor 22 is coupled to the hydraulic circuit corresponding to the circuit shown in FIG. 1, its output shaft 23 rotates simultaneously with the crankshaft of the internal combustion engine, and the movement and correct phase of the vibrating body of the internal combustion engine. Rotate simultaneously in each relationship. Thus, since the unbalance 24 rotates at the same rpm as the internal combustion engine crankshaft, and the second unbalance 28 rotates twice as fast, these unbalances can compensate for the primary and secondary moments of inertia of the internal combustion engine. To generate force.

Moreover, this invention can also be implemented also in the apparatus for compensating the vibration force generate | occur | produced by the propeller of a ship. Such a device may have a separate hydraulically driven motor supplied from a hydraulic pump driven by the main engine. Alternatively, a separate unbalance can be added to the above-mentioned device, i.e. a device with one or two unbalances to compensate for the Buddha moment with the main engine, and a separate unbalance can also be hydraulically driven through the mechanical transmission. It can be connected to the motor, whose gear ratio corresponds to the ratio of the frequency of the propeller's force to the rpm of the hydraulic motor.

In all the embodiments described above it can be seen that the pump operating the rotating unbalance drive motor can be driven from a suitable shaft of the main engine, such as a crank shaft or an intermediate shaft of a cam shaft drive.

Claims (1)

At least one rotary unbalance (9, 24, 28) and the connecting drive motor (12, 22) away from the internal combustion engine in the longitudinal direction of the ship, and the rpm of the drive motor, depending on the rpm and phase angle of the internal combustion engine; In the device composed of the synchronous devices 16, 17 for controlling the phase angle, the drive motors 12, 22 are bi-displacement hydraulic motors, and the internal combustion engine (14) is supplied through the supply conduit (14) and the return conduit (15). Apparatus for compensating the free moment arising from the inertial force of the internal combustion engine (2) used as the main propulsion engine of the ship (1), characterized in that it is connected to a bi-displacement hydraulic pump (13) driven by 2).

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