RU181841U1 - FRAME OF THE SHOCK-DOWN SHIP DIESEL GENERATOR - Google Patents

Abstract

The utility model relates to the field of common frame designs for amortized marine diesel generators. The frame contains longitudinal beams for the diesel engine and generator, transverse ties of the longitudinal beams, lower and upper shelves of the longitudinal beams, lower and upper strips of the transverse ties of the longitudinal beams, transverse stiffeners along the left and right sides on the outer sides of the longitudinal beams between the upper and lower shelves to form corresponding external cells of the frame in the areas of the diesel engine and generator, respectively. A trough-like steel sheet welded from the longitudinal side to the upper shelves, and with the inner side to the transverse connections of the longitudinal beams. The longitudinal beams with shelves on the left and right sides are made integral along the entire length of the frame, while the shelves under the legs of the generator are mounted on the said longitudinal beam on the stiffeners, the common frame within the middle transverse connections is made with additional longitudinal beams at a distance from the main beam equal to from zero to half the width of the upper flange of the longitudinal beam. The technical solution provides a decrease in the frequency of free vibrations and a significant increase in the rigidity of the common frame.

Description

The utility model relates to the field of common frame designs for amortized marine diesel generators.

The design of the common frames of amortized marine diesel generators are known and diverse {Braslovsky MI Ship diesel generators of low power / M.I. Braslovsky. - L. “Shipbuilding”, 1968. - 174 p. (p. 9-11, fig. 1-3)}. They depend on the characteristics of the diesel generators for which they are designed, as well as on the area of its location on the ship.

The loads perceived by the general frame of marine diesel generators include:

- loads from the dead weight of the diesel engine and generator, distributed within the overall frame;

- inertia caused by the ship’s engine during onboard, keel and vertical roll, during braking and in the event of a collision with an obstacle;

- the forces arising from the overturning moment, the inertial forces of the unbalanced moving parts and the moments of inertia of the engine.

For marine diesel generators, the probability of vibrational damage to the common frames increases if the diesel is unbalanced {Minasyan MA, Medvedev VV Vibration reduction of diesel generators and ship structures due to damping with mastic coatings. Shipbuilding No. 3, 2006 (p. 36-38, Fig. 2)} - prototype.

Vibration measurements of a larger number of DG 5AL 25 diesel generators with unbalanced five-cylinder, four-stroke supercharged 5CHN 25/30 engines on some refrigerated vessels showed that the amplitude of elastic vibrations of the supporting structures of the common frames of diesel generators exceeds the permissible norm of 0.16 mm in Rules of the Russian Maritime Register of Shipping {M. Minasyan Experience in the practical use of spiral cable vibration isolators in a ship. Engine-building No. 2, 1996 (p. 35-37)}. The excess of vertical and traverse vibration of a gas turbocharger (0.6-1.0 mm), diesel block (0.36-0.45 mm) and generator paws (0.3-0.8 mm) is especially great - s. 36.

For convenience, justification of these shortcomings of the known (factory - full-time) common frame of the diesel generator DG 5AL 25 in FIG. 1 is a general view thereof, and FIG. 2 - bottom view of the frame with the designation of the positions of all elements:

1-4 - longitudinal beams (Fig. 1, 2);

5-10 - reference strip (Fig. 1);

11-16 - transverse ties (braces) of the longitudinal beams 1, 2 (Fig. 1, 2);

17 - end transverse connection of the longitudinal beams 3, 4 (Fig. 1, 2);

18-23 - the upper shelves of the transverse ties of the longitudinal beams 1, 2 (Fig. 1);

24 - trough-like sheet (Fig. 1);

25-35 - transverse stiffeners (Fig. 1, 2);

36-46 - lower shelves of the transverse ties of the beams 1, 2 (Fig. 2);

47-50 - intermediate transverse connections of the longitudinal beams 3, 4 (Fig. 2);

A - holes made in the longitudinal beams 1, 2 (Fig. 1, 2).

I-X - external cell sections (I-VI in the diesel area, VII-X in the generator area).

The well-known common frame of a marine diesel generator contains longitudinal beams for diesel and generator 1-4 (Fig. 1, 2), common lower 5, 6 support strips of the diesel generator and individual upper strips 7, 8 under the support legs of the diesel and 9, 10 - generator, transverse connections of 11-17 longitudinal beams 1-4, upper 18-23 and lower 36-46 regiments of transverse connections 11-17, transverse connections of longitudinal beams 3, 4 in the region of the generator, transverse stiffeners 25-35 from the outside longitudinal beams 1, 4, trough-like sheet 24.

A trough-like steel sheet is welded from the longitudinal side to the supporting strips 9, 10 (Fig. 1), and with the inner side to the transverse connections 17 (Fig. 1) and 47-50 (Fig. 2) and the transverse connections 36-46 longitudinal beams 3, 4 (Fig. 2).

On the lower side of the common frame, transverse connections 17, 47-50 are made with shelves 42-46.

As a result of increased vibration on some refrigerated vessels on the upper supporting strips 7, 8 (Fig. 1) of the longitudinal beams 1, 2 of the common frames of DG 5AL 25 diesel generators, approximately in the middle part (cell section VI, Fig. 1) - location the flywheel of the diesel engine cracked.

A significant drawback of the well-known common frame of diesel generators

DG 5AL 25 is a design imperfection, namely insufficient frame stiffness, which leads to an unacceptable increase in vibration displacement amplitudes, especially at the reverse - frequency (12.5 Hz) of a single-node vibration form. Therefore, increased vibration of the frame led to the formation of cracks in the nodal points, that is, in the region of the diesel flywheel (cell section VI, Fig. 1).

The technical result of the proposed utility model is to improve the design of the common frame in order to ensure its reliability for the prevention of cracks on the example of frames of marine diesel generators of the DG 5AL 25 brand.

The total amortized frame of the marine diesel generator contains longitudinal beams for diesel and generator, transverse links of longitudinal beams, lower and upper shelves of longitudinal beams, lower and upper strips of transverse connections of longitudinal beams, transverse stiffeners on the left and right sides on the outside of the longitudinal beams between upper and lower shelves with the formation of the corresponding external cells of the frame in the areas of location of the diesel engine and generator, respectively. A trough-like steel sheet welded from the longitudinal side to the upper flanges, and with the inner side to the transverse connections of the longitudinal beams, according to the utility model, the technical result is achieved in that:

1. Longitudinal beams with shelves on the left and right sides are made integral along the entire length of the frame;

2. Shelves under the legs of the generator are installed on the said longitudinal beams on stiffeners;

3. The overall frame to provide additional rigidity within the middle transverse ties is made with additional longitudinal beams at a distance from the main beam equal to zero to half the width of the upper flange of the longitudinal beam.

The technical solution provides a decrease in the frequency of free vibrations and a significant increase in the rigidity of the common frame, therefore, the prevention of dangerous resonances, cracks in the frame and the achievement of its reliability in general.

The essence of the technical solution - utility model is illustrated by the drawings shown in FIG. 3, 4, where are shown:

in FIG. 3 general view of the proposed - a new general frame of a marine diesel generator;

in FIG. 4 - view of the frame from below,

in FIG. 5-6 - view of the frame with cuts in the middle part,

in FIG. 7-8 is a view of the middle part of the frame with cuts on an enlarged scale,

Where:

51, 52 - sections of the upper shelves of the longitudinal beams in the area of the generator on the left and right sides (Fig. 3);

53, 54 - inclined strip (Fig. 3);

55-59 - transverse stiffeners between the bands 9 and 52, 10 and 51 (Fig. 3);

60-63, 64-67 - additional longitudinal beams within the cross-links 15, 16, 47-49 [Fig. 3 (62, 63), 4-8];

Improving the design of the common frame in order to ensure its reliability for preventing cracks on the example of a frame of a shock-absorbed DG 5AL 25 marine diesel generator is as follows:

1. Longitudinal beams 1, 4 and 2, 3, respectively, on the left and right sides are made integral, the length along the entire length of the frame of the diesel generator.

2. The upper strips 7, 58 and 8, 51 (Fig. 3) of the longitudinal beams 1 and 2, respectively, along the left and right sides are made integral along their entire length;

3. Shelves 51, 52 (Fig. 3) under the legs 9, 10 of the generator are mounted on said longitudinal beam 1, 4 (2, 3) (Fig. 3) on stiffeners 55-59 (Figs. 3, 4-8) ;

4. Within the middle cross-links 15, 16, 47, 48, 49 (Fig. 4) of the longitudinal beams 1, 4 and 2, 3, additional longitudinal beams 60-63 (left side) and 64-67 (right side) are provided at a distance from the main longitudinal beam 1 (2) equal to zero to half the width of the upper shelf 7 (8) of the beam (Fig. 3-8).

In the proposed utility model (for example, the frames of marine diesel generators of the DG 5AL 25 brand), the longitudinal beams 1, 4 (on the right) and 2, 3 (on the left) of the beams are integral throughout the entire length of the frame, with shelves 7, 52 (on the right) and 8 51 (left), by installing shelves 9 (right) and 10 (left) under the legs of the generator on said longitudinal beams 1, 4 and 2, 3 on stiffeners 55-59, using additional longitudinal 60-63 (right) and 64- 67 (left) contribute to increasing the rigidity of the frame, reducing its own frequency of oscillation. A frame with a low frequency of free vibrations, when the diesel generator is operating, the detuning coefficient from the resonance increases, and the dynamic coefficient decreases, that is, the amplitudes of the forced vibrations and stresses in the vibration nodes of the frame decrease, thereby preventing cracks and thereby ensuring the reliability of the frame.

Considering that the design of the frames of shock-absorbed marine diesel generators includes the main elements, such as longitudinal beams, transverse ties of the beams with the corresponding shelves and stiffeners, the proposed technical solution provides the possibility of their application, including for frames not only of many ship diesel generators, but also in stationary, diesel and other technical facilities.

Claims (1)

A frame of a shock-absorbed marine diesel generator containing longitudinal beams for diesel and generator, transverse links of longitudinal beams, lower and upper shelves of longitudinal beams, lower and upper strips of transverse connections of longitudinal beams, transverse stiffeners on the left and right sides on the outside of the longitudinal beams between upper and lower shelves with the formation of the corresponding external cells of the frame in the areas of the diesel engine and generator, respectively, a trough-like steel sheet welded from the longitudinal side to the to the upper shelves, and with the inner side to the transverse connections of the longitudinal beams, characterized in that the longitudinal beams with the shelves on the left and right sides are made integral along the entire length of the frame, while the shelves under the generator legs are mounted on the said longitudinal beam on the stiffeners the frame within the middle transverse ties is made with additional longitudinal beams at a distance from the main beam, equal to zero to half the width of the upper flange of the longitudinal beam.

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