JPH1095397A - Vibration damping device for marine engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damping device for a marine engine which can attain miniaturization of the device and lightening of weight and easily reduce an influence of torsional vibration and vertical vibration transmitted to a ship body through an engine without generating a large change of design. SOLUTION: A torsional damper, connecting a first outer ring 14 and an opposite output shaft end 6a by a vibration absorber 15 of leaf spring or the like, and a vertical damper, formed with an oil chamber 13 between the first outer ring 14 of the torsional damper and a second outer ring 12 annularly provided in a peripheral side thereof, are combined, a side surface of the second outer ring 12 of this vertical damper is mounted in a partition of an engine or a support plate in a ship body side, to reduce an influence of both shaft system vertical vibration and torsional vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping device for a marine engine mounted on a marine vessel as a propulsion engine, and more particularly, a counter-output shaft end side of the marine engine mounted on a marine vessel for driving a propulsion device and receiving a thrust generated therein. The present invention relates to a marine engine vibration damping device installed in a marine engine.

[0002]

2. Description of the Related Art In a long-stroke engine accompanying a decrease in the shaft rotation speed, the rigidity of the crankshaft in the axial direction decreases, and the natural frequency of the longitudinal vibration of the shaft system decreases. As a result, the torsional natural frequency and the longitudinal natural frequency of the shaft system are close to each other, and near the torsional resonance point, the axial vibrating force transmitted from the shaft system to the hull via the engine increases. To prevent this, in conventional engines, a damper is arranged at the end of the output shaft of the shaft system to reduce the effects of torsional and longitudinal vibrations. For this purpose, a vertical damper will be installed.
It is important to reduce both torsional vibration and longitudinal vibration in order to reduce the axial vibrating force transmitted to the hull from the shaft system via the engine, but in the prior art, both are separate. It is difficult to install them in the axial direction because of space.

That is, a vertical damper installed in a conventional marine engine has a structure schematically shown in FIG. 2, and the oil in an oil chamber 3 acts as a spring or a damping element, thereby forming a shaft. The longitudinal displacement of the end 6a is suppressed. still,
In the figure, reference numeral 1 denotes an engine main body, 2 denotes a casing (outer ring) for forming an oil chamber 3, and the casing (outer ring) 2
Is fixed to the partition wall. Reference numeral 7 denotes a propulsion device mounted on the output shaft side of the shaft system 6. A torsional damper installed in a conventional marine engine has a structure schematically shown in FIG. 3, and includes a rotational inertia mass of an outer ring 4 provided around a shaft end 6a and an outer ring. Leaf spring 5 connecting the shaft end 4 and the shaft end 6a
By setting the natural frequency of the one-degree-of-freedom rotary system having the torsional rigidity at the torsional resonance point of the shaft system, it functions as a dynamic vibration absorber. In the prior art, both are separate devices.

[0004]

Therefore, as described above, the axial displacement of the shaft system which excites the shaft system vibrating force near the torsional resonance point is caused by longitudinal vibration, and the axial displacement is caused by longitudinal vibration. This is given as the sum of both due to torsional vibration, and it is not possible to sufficiently reduce the shaft-system vibrating force only by suppressing one of longitudinal vibration and torsional vibration. However, when both the vertical damper and the torsional damper shown in FIGS. 2 and 3 are juxtaposed, it is difficult to juxtapose them in terms of space because the device becomes large. In addition, the crankshaft is further extended from the front end of the engine where the vertical damper is installed, and the torsional damper is installed at the tip of the shaft.Therefore, it is necessary to make the crankshaft longer than conventional products. Instead, the vibration weight of the crankshaft increases, which leads to an increase in the vibration of the shaft. The present invention has been made in view of the drawbacks of the prior art, and has been made to reduce the size and weight of the apparatus, and to reduce the influence of torsional vibration and longitudinal vibration transmitted to the hull via the engine without causing a significant design change. An object of the present invention is to provide a marine engine vibration damping device that can be easily performed.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a vibration damping device for a marine engine, which is mounted on a marine vessel and drives a propulsion device, and is installed on the end of the marine engine opposite to an output shaft which receives a thrust generated therein. 1 A torsional damper in which an outer ring and a non-output shaft are connected by a leaf spring or other vibration absorber, and a longitudinal direction in which an oil chamber is formed between a first outer ring of the torsional damper and a second outer ring provided on the outer peripheral side thereof. A damper is combined, and the side surface of the second outer ring of the vertical damper is attached to a partition wall of the engine or a support plate on the hull side to reduce the effects of both the axial vibration and the torsional vibration. That is, the marine engine vibration damping device including the torsional damper and the vertical damper is generally attached to the engine bulkhead via the side surface of the second outer ring. It may be attached to a fixed support plate.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. It's just FIG.
FIG. 1 shows a schematic diagram of a marine engine vibration damping device as a longitudinal torsional damper according to an embodiment of the present invention. A rotary inertia mass 14 serving as a first outer ring is installed via a leaf spring 15 on a counter output shaft end 6a protruding from the engine bulkhead 1a on the opposite side of the propulsion device 7. Here, by determining the spring constants of the rotary inertia mass 14 and the leaf spring 15 so that the natural frequency of the one-degree-of-freedom rotary system composed of the rotary inertia mass 14 and the leaf spring 15 coincides with the torsional resonance, the torsion of the shaft system is determined. A dynamic vibration absorber for vibration can be configured.

Next, a vertical damper in which an oil chamber 13 is formed by the outer peripheral portion of the rotary inertia mass 14 (first outer ring) and the inner peripheral portion of the casing 12 (second outer ring) is formed. The side surface of the casing 12 (second outer ring) is fixed to the partition 1 a of the engine body 1. As a result, the rotational inertia mass 14
Rotates in a free state and functions as a dynamic vibration absorber, and the oil filled in the oil chamber 13 between the casing 12 and the second outer ring installed outside the rotary inertia mass 14 is supplied to the shaft system 6. Acts as a spring or a damping element with respect to the vibration in the axial direction, and forms a vertical damper between the shaft end 6a and the casing 12 or the engine body 1. As described above, since the vertical damper portion does not restrict the shaft system with respect to the rotation on the inertia mass 14 side by the interposition of the oil chamber 13, the operation of the torsional damper is maintained.

Accordingly, the present invention suppresses the longitudinal vibration and the torsional vibration of the shaft system by providing the vertical damper and the torsional damper in a compact space, and as a result, the vibration is transmitted from the shaft system to the hull via the engine. Exciting force can be reduced.

More specifically, the embodiment of the present invention will be described in more detail with reference to FIG. 1. A collar (not shown) is provided on the outer periphery of a rotary inertial mass 14, which is a first outer ring of a torsional damper installed at the non-output shaft end 6a. ), And an oil chamber 13 is formed between the oil chamber 13 and a casing 12 which is a second outer ring installed on the outer periphery thereof.
The side surface of the casing 12, which is the outer ring, is
a. Therefore, in the present invention, an oil chamber 13 is provided on the outer periphery of the rotary inertial mass 14 functioning as a dynamic vibration absorber, and the oil in the oil chamber 13 acts as a spring or a damping element, thereby forming a vertical damper. As a result, the present invention can reduce the influence of both the shaft system longitudinal vibration and the torsional vibration, and realizes a compact structure by being integrated.

[0010]

As described above, according to the present invention, it is possible to reduce both the longitudinal vibration and the torsional vibration of the shaft system with a structure that is reasonable in space. As a result,
Due to the effect of torsional vibration, a phenomenon in which the axial vibrating force transmitted from the shaft system to the hull via the engine is increased, and the structure of the upper structure of the hull can be reduced. In particular, according to the present invention, the vertical damper and the torsional damper are integrated and configured as a single device, so that the device can be reduced in size and weight, and the design change of the shaft system (crankshaft), that is, the engine body side during installation is small. It is reasonable.

[Brief description of the drawings]

FIG. 1 is a schematic view of a marine engine vibration damping device as a longitudinal torsional damper according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a vertical damper mounted on a conventional engine.

FIG. 3 is a schematic diagram showing a torsional damper mounted on a conventional engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine main body 2 Casing 3 Oil chamber 4 Rotary inertia mass 5 Spring 6 Shaft system 6a Shaft end 7 Propeller 12 Second outer ring (casing) 13 Oil chamber 14 First outer ring (Rotary inertial mass) 15 Leaf spring (vibration absorption) body)

Claims (1)

[Claims] 1. A damper for a marine engine mounted on a ship for driving a propulsion device and receiving a thrust generated therefrom, the damper for a marine engine being installed on a side opposite to an output shaft of the marine engine. And a torsional damper having a hydraulic chamber formed between a first outer ring of the torsional damper and a second outer ring provided on the outer peripheral side of the torsional damper. A vibration control device for a marine engine, wherein the side surface of the second outer ring is mounted on a partition wall of the engine or a support plate on the hull side to reduce the influence of both the axial vibration and the torsional vibration.