CN117068357A - Vibration isolation system of ship propulsion system and assembly method - Google Patents

Abstract

The vibration isolation system of the ship propulsion system comprises a propulsion connector and a vibration isolator II, wherein the vibration isolator II comprises an inner sleeve II, an outer sleeve II and a rubber body II between the inner sleeve II and the outer sleeve II, wherein the inner sleeve II is connected with one end of the propulsion connector, the other end of the propulsion connector is connected with a propeller, and the outer sleeve II is connected with a support frame on the outer side of a ship body. The vibration isolation system of the ship propulsion system can normally transmit the propulsion power of the external propeller to the ship body to provide power for ship navigation, and can attenuate longitudinal and transverse vibration generated in the propulsion process, so that the comfort and concealment of the ship are improved.

Description

Vibration isolation system of ship propulsion system and assembly method

Technical Field

The application relates to the technical field of ship propulsion systems and vibration isolation thereof, in particular to a vibration isolation system of a ship propulsion system and an assembly method thereof.

Background

The propulsion system is used as a core component of a ship power system to provide propulsion power for the ship and ensure that the ship can normally run. Because the propulsion system has transverse and longitudinal vibration noise in the working process, the vibration noise can be transmitted to other parts of the ship, the comfort of ship operators is seriously reduced, and the risk of resonance failure of other structural members exists, so that the vibration isolation measures are very important for the propulsion system.

At present, the ship power propulsion mode with an external propulsion system is provided. As shown in fig. 1, the propeller 2 is located outside the ship body, the external propeller 2 does not rotate itself, and a power unit for providing thrust is provided inside the external propeller. Unlike the built-in power systems common in the prior art, the thrust power source of the thrust machine does not come from the interior of the ship, and thus does not require a propeller connected to the outside by a drive shaft for rotation to provide thrust. As shown in fig. 1, the steel structure of the ship body is generally shown in fig. 1, the outermost layer is a ship body outer side supporting frame 3, the ship body inner side supporting frame 4 is located inside the ship body outer side supporting frame 3, and a narrow equipment installation space is formed between the ship body outer side supporting frame 3 and the ship body inner side supporting frame 4. The thrust of the propeller 2 can directly act on the ship outside support frame 3 to provide ship propulsion power. As can be seen from fig. 1, the external propeller 2 generates vibration noise in the transverse direction and the longitudinal direction during operation, and if no corresponding vibration isolation measures are adopted between the propeller 2 and the ship body, the vibration noise is directly transmitted to the inside of the ship body. Especially when sailing underwater, this vibration noise will have a very large impact on the comfort and concealment of the ship.

By searching, the prior art has corresponding technical literature disclosure for vibration isolation of a ship propulsion system. For example, the application patent publication with publication number of CN113247225A named as an underwater vehicle flexible propulsion system and an underwater vehicle. The utility model provides an underwater vehicle flexible propulsion system and underwater vehicle, underwater vehicle flexible propulsion system includes the propulsion motor who is fixed in the underwater vehicle with the isolator, the propeller, one end rotatable run through the underwater vehicle and with the tail shaft of propeller connection, the elastic coupling, vibration isolation thrust bearing, vertical shock absorber, tail shaft sealing device, tail shaft protection elastic bearing and tail shaft flexible support bearing, vibration isolation thrust bearing's both ends are connected with propulsion motor output shaft and tail shaft through elastic coupling and vertical shock absorber respectively, tail shaft sealing device, tail shaft protection elastic bearing and tail shaft flexible support bearing overlap in proper order and locate the tail shaft and be connected with the underwater vehicle. The reference aims at the vibration isolation proposal provided by the ship propulsion system with built-in propulsion power, and is not suitable for vibration isolation of an external power source because the positions of the vibration power sources are different.

For example, the publication number of the application is CN115306864A entitled "semi-actively controlled zero-stiffness vibration isolation device and method for a submarine propulsion shaft system". The application discloses a semi-actively controlled zero-stiffness vibration isolation device of a submarine propulsion shaft system, which comprises a negative stiffness mechanism capable of axially moving relative to the propulsion shaft, an automatic balance position adjusting mechanism for adjusting the position of the negative stiffness mechanism, a positive stiffness mechanism and a vibration semi-active control system; the negative stiffness mechanism comprises a movable steel frame, a radial damper, a radial spring, a thrust disc, a thrust bearing and a thrust flange, wherein the thrust disc, the thrust bearing and the thrust flange are arranged on the thrust shaft; the outer side of the negative rigidity mechanism is covered with a submarine skeleton, the submarine skeleton is fixedly connected with the submarine shell, a plurality of automatic balance position adjusting mechanisms are arranged between the submarine skeleton and the periphery of the negative rigidity mechanism at intervals along the circumferential direction, and a positive rigidity mechanism is arranged between the submarine skeleton and two ends of the negative rigidity mechanism; the positive stiffness mechanism comprises a plurality of longitudinal springs and a switch controllable damper; the automatic balance position adjusting mechanism comprises a swing oil cylinder, a gear and a rack. According to the technical scheme analysis provided by the comparison document, the ship power system aiming at the comparison document is provided with a rotating connecting shaft, and the ship power system is not matched with the application scene of the ship body without the rotating shaft action of the external propulsion system applied by the application.

Therefore, the vibration isolation system and the assembly method of the ship propulsion system, which can aim at external propulsion power, are provided in the field to have important significance.

Disclosure of Invention

The application provides a vibration isolation system of a ship propulsion system, which comprises a propulsion connector and a vibration isolator II, wherein the vibration isolator II comprises an inner sleeve II, an outer sleeve II and a rubber body II between the inner sleeve II and the outer sleeve II, wherein the inner sleeve II is connected with one end of the propulsion connector, the other end of the propulsion connector is connected with a propeller, and the outer sleeve II is connected with a support frame on the outer side of a ship body.

Further, the device also comprises a second connecting shaft, one end of the second connecting shaft is connected with the second inner sleeve, and the other end of the second connecting shaft is connected with the propelling connector.

Further, the second outer sleeve is provided with a second flange provided with a bolt hole, and the second outer sleeve is fixed on the support frame on the outer side of the ship body through the second flange by bolts.

Further, the propelling connector is a connecting flange, a cavity II is formed in the connecting end of the connecting flange and the connecting end of the propeller, and the connecting shaft II is sleeved inside the connecting flange and penetrates through the cavity II to be connected with the connecting flange through an end cover.

Further, the vibration isolator also comprises a first connecting shaft, one end of the first connecting shaft and the second connecting shaft are integrally formed into a connecting shaft, and the other end of the first connecting shaft is connected with the first vibration isolator; the vibration isolator I comprises an inner sleeve I, an outer sleeve I and a rubber body I between the inner sleeve I and the outer sleeve I, wherein the connecting shaft I is connected with the inner sleeve I, and the outer sleeve I is connected with a support frame on the inner side of the ship body; the first outer sleeve of the vibration isolator is provided with a first flange provided with a bolt hole, and the first outer sleeve is fixed on the inner side supporting frame of the ship body through the first flange and the bolt.

Further, the inner side of the flange I of the outer sleeve I is provided with a concave plane I, the connecting shaft I penetrates through the inner sleeve I and then is connected with the limit cover, and the limit cover and the inner side support frame of the ship body are provided with a longitudinal clearance I; the limiting cover is provided with a convex surface matched with the concave plane I, and a longitudinal gap II is formed between the convex surface and the concave plane I after the limiting cover is connected with the connecting shaft I.

Further, after the limiting cover is connected with the connecting shaft, the outer side face of the limiting cover and the inner side face of the outer sleeve are provided with transverse gaps.

The assembly method of the vibration isolation system of the ship propulsion system is also provided, and comprises the following steps:

the vibration isolator assembly comprises the steps of firstly, mounting an inner sleeve I of a vibration isolator I and an inner sleeve II of a vibration isolator II on a connecting shaft in interference fit, and mounting a limiting cover to one end of the vibration isolator I of the connecting shaft;

the vibration isolation system is assembled, a connecting shaft and a first vibration isolator extend into the hull outside support frame, and a first outer sleeve of the first vibration isolator is fixed to one end of the hull inside support frame; then the second outer sleeve of the vibration isolator II is fixed to the outer end face of the ship body outer side support frame, and the end part of the connecting shaft is exposed;

assembling a propulsion system, namely sleeving a connecting flange on the exposed end part of the connecting shaft, and fixing an end cover on the exposed end surface of the connecting shaft; the propeller is installed and fixed on the connecting flange.

In the assembling step of the vibration isolation system, when the first outer sleeve of the first vibration isolator is fixed to one end of the inner side support frame of the ship body, an access hole is formed in the outer side support frame of the ship body, and the first outer sleeve is fixed to one end of the inner side support frame of the ship body through bolts from the outer side of the outer side support frame of the ship body through the access hole.

Further, in the vibration isolator assembling step, a first step, a second step and a third step are sequentially formed on the connecting shaft along the axial direction, a first outer sleeve of the vibration isolator is in interference fit with the first step, a second inner sleeve of the vibration isolator is in interference fit with the third step, and a second outer sleeve of the vibration isolator is abutted against the outer end face of the ship body outer support frame after the connecting shaft stretches into the ship body outer support frame in the vibration isolator system assembling step.

Compared with the prior art, the technical scheme of the application has the following beneficial effects:

1. the vibration isolation system of the ship propulsion system can normally transmit the propulsion power of the external propeller to the ship body to provide power for ship navigation, and can attenuate longitudinal and transverse vibration generated in the propulsion process, so that the comfort and concealment of the ship are improved.

2. The risk of failure of the vibration damper caused by the load overrun of the propeller due to the dead weight is considered while longitudinal and transverse vibration generated in the propelling process is damped, the inside of the ship body is connected by using the extending rigid connecting shaft, and the gravity load is provided by the lever principle to bear counter moment. Therefore, the method has higher stability and reliability.

3. The vibration isolation system assembly method of the ship propulsion system is simple in assembly and can be suitable for a narrow equipment installation space between the ship outside support frame and the ship inside support frame.

Drawings

Fig. 1: a propulsion system schematic diagram of an external propulsion system;

fig. 2: the vibration isolation system structure of the propulsion system provided by the first embodiment is shown in a schematic diagram;

fig. 3: the vibration isolation system structure of the propulsion system provided by the first embodiment is shown in a second schematic diagram;

fig. 4: the vibration isolation system connecting flange structure schematic diagram of the propulsion system is provided in the first embodiment;

fig. 5: the first embodiment provides a schematic diagram of a vibration isolation system double vibration isolators of a propulsion system;

fig. 6: a partial enlarged view of the vibration isolator provided in the second embodiment;

fig. 7: the vibration isolation system structure of the propulsion system provided by the first embodiment is shown in a schematic diagram III;

fig. 8: the step diagram of the assembling method provided in the second embodiment is first;

fig. 9: step illustration II of the assembly method provided in the second embodiment;

fig. 10: the assembly method provided in the second embodiment is shown in the third step.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Embodiment one: vibration isolation system of ship propulsion system

The embodiment provides a concrete structural implementation mode of a vibration isolation system of a ship propulsion system. The vibration isolation system of the ship propulsion system comprises a propulsion connector 1 and a vibration isolator II 5, wherein the vibration isolator II 5 comprises an inner sleeve II 51, an outer sleeve II 52 and a rubber II 53 between the inner sleeve II and the outer sleeve II, the inner sleeve II 51 is connected with one end of the propulsion connector 1, the other end of the propulsion connector 1 is connected with a propeller 2, and the outer sleeve II 52 is connected with a support frame 3 outside a ship body. The second rubber body 53 provides longitudinal rigidity for carrying the propulsion acceleration load generated by the propeller 1 and damping longitudinal vibration, and provides transverse rigidity for bearing the self-weight load of the propeller 2 and damping transverse vibration. There are various embodiments of the structure of the connector 1, and a simpler structure may be a shaft-like connection as shown in fig. 2 or 3. In fig. 2, the hatched portion shows a vibration isolator two 5, which is connected to the hull outside support frame 3 on the one hand and to the propulsion connector 1 on the other hand, the propulsion power of the propeller 2 acting on the vibration isolator two 5 through the propulsion connector 1. When the propeller 2 generates a forward or backward propulsion acceleration load, the vibration isolator 2 needs to have a certain longitudinal rigidity, which is longitudinally along the forward direction of the ship. This longitudinal stiffness needs to be able to withstand said propulsion acceleration load on the one hand and to dampen the longitudinal vibrations transmitted by the propulsion device 2 to the propulsion connector 1 on the other hand, in a similar manner as in the transverse vertical advance direction. Therefore, an elastomer having such characteristics is provided in the vibration isolator 2, and the elastomer having such characteristics is satisfactory in the prior art.

A preferred embodiment of the push-on connector 1 is that the push-on connector 1 is a connection flange 101. The connecting flange 101 and the connecting end of the pushing connector 1 are a flange plate and are fixedly connected through bolts.

In this embodiment, the second outer sleeve 52 has a second flange 54 with bolt holes, the second outer sleeve 52 is fixed on the outer hull support frame 3 by bolts through the second flange 54, and the second outer sleeve 52 and the outer hull support frame 3 are in clearance fit. The propulsion connector 1 and the vibration isolator II 5 are fixedly connected through bolts, the equipment is simpler, and the connection can be high.

In this embodiment, the propulsion connector 1 further includes a second connection shaft 72, where one end of the second connection shaft 72 is connected to the second inner sleeve 51, and the other end is connected to the propulsion connector 1. The second connecting shaft 72 and the second inner sleeve 51 are in interference fit.

To further optimize the ease of assembly between the second connection shaft 72 and the push-on connector 1, a reliable connection between the two is ensured. The connecting flange 101 and the propeller 2 are provided with a second cavity 102 at the connecting end, and the second connecting shaft 72 is sleeved inside the connecting flange 101 and penetrates through the second cavity 102 to be connected with the connecting flange 101 through an end cover 103. During assembly, the second connecting shaft 72 can penetrate into the second cavity 102 to connect with the end cover 103, so that the assembly of the push-on connector 1 is completed. The other end of the second connecting shaft 72 is first in interference fit with the second inner sleeve 51, and then is mounted to one end of the hull outside support frame 3 through the second outer sleeve 52 of the second vibration isolator 5 along with the whole propulsion connector 1 by bolts. In order to ensure the connection reliability of the connecting flange 101 and the second connecting shaft 72, the sleeving section of the connecting flange 101 and the second connecting shaft 72 is fixedly connected after penetrating through the pin 104.

Figure 2 shows the basic method and basic structure of vibration isolation of a marine propulsion system. Since the propeller 2 is often provided with a relatively large dead weight as an external power source, this basic solution can only be operated reliably if the dead weight of the propeller 2 is not sufficient to exceed the tolerance of the longitudinal stiffness of the elastomer inside the vibration isolator 2. When the dead weight load of the propeller 2 is too large, the vibration isolator 2 can generate larger longitudinal load on the elastic body in the vibration isolator 2 and possibly cause the elastic body in the vibration isolator 2 to break and fail, so that the propelling power generated by the propeller 2 cannot be normally transmitted to the ship body, and serious consequences of failure of both power transmission and vibration isolation are caused.

A more preferred embodiment is therefore presented. As shown in fig. 5 and 6, a first connecting shaft 71 is further provided on the basis of the above embodiment, one end of the first connecting shaft 71 and the second connecting shaft 72 are integrally formed into a connecting shaft 7, and the other end is connected with the first vibration isolator 6; the first vibration isolator 6 comprises a first inner sleeve 61, a first outer sleeve 62 and a first rubber body 63 vulcanized therebetween, a first connecting shaft 71 is connected with the first inner sleeve 61, and the first outer sleeve 62 is connected with the inner side supporting frame 4 of the ship body. The first sleeve 62 of the first vibration isolator 6 has a first flange 64 with bolt holes, and the first sleeve 62 is bolted to the hull inner support frame 4 via the first flange 64. The first connecting shaft 71 is used as a extension of the second connecting shaft 72 and is connected with the inner side supporting frame 4 of the ship body through the first vibration isolator 6. Thus, a lever is formed with the vibration isolator II 5 as a fulcrum, and the fixed connection relationship between the vibration isolator I6 and the ship inner side support frame 4 provides a counter moment for counteracting the self-weight load of the propeller 2. The first sleeve 61 and one end of the first connecting shaft 71 are in interference fit, and the vulcanized first rubber 63 between the first sleeve 61 and the first sleeve 62 is similar to the second rubber 53 of the second vibration isolator 5, and provides vibration attenuation and longitudinal and transverse rigidity for bearing load. According to the preferred embodiment, the scheme of the two vibration isolators 5 and the first vibration isolator 6 provides better longitudinal and transverse vibration damping performance on the premise of ensuring that the self-weight load of the propeller 1 can be borne.

In this embodiment, the connecting shaft 7 has a step one 73, a step two 74, and a step three 75 in order along the axial direction, wherein the step one 73 is sleeved with the inner sleeve one 61, the step two 74 is sleeved with the inner sleeve two 51, and the step three 75 is sleeved with the push-on connector 1.

Since acceleration loads are generated when the propeller 1 provides forward or reverse propulsion power, the dual isolator solution described above is normally capable of withstanding such loads. However, when the acceleration load of the ship due to external factors such as abnormal impact is likely to exceed the load bearing capacity of the rubber body one 63 and the rubber body two 53, in this extreme case, the rubber body one 63 and the rubber body two 53 fail, and it is required to ensure the normal transmission of the power preferentially. Preferred embodiments are provided for this purpose:

the opposite inner side of the flange one 64 of the outer sleeve one 62 is provided with a concave plane one 65, the connecting shaft one 71 penetrates through the inner sleeve one 61 and then is connected with the limit cover 8, and the limit cover 8 and the inner side support frame 4 of the ship body are provided with a longitudinal gap one 81; the limiting cover 8 is provided with a convex surface 83 matched with the first concave plane 65, and a second longitudinal gap 82 is formed between the convex surface 83 and the first concave plane 65 after the limiting cover 8 is connected with the first connecting shaft 71. When the first rubber body 63 and the second rubber body 53 fail, the longitudinal gap II 82 or the longitudinal gap I81 is reset, and the limiting cover 8 can be contacted with the concave plane I65 or the end face of the inner side support frame 4 of the ship body to ensure that the power can be normally transmitted, and the connecting shaft 7 cannot be separated. Under normal working conditions, the second longitudinal gap 82 or the first longitudinal gap 81 is larger than zero, so that the limiting cover 8 and the first concave plane 65 or the inner side support frame 4 of the ship body can not be in direct contact, and the vibration isolation performance of the ship body is ensured. The outer surface of the limit cover 8 can be coated with a buffer layer with a certain thickness so as to buffer the hard contact of the limit cover 8 after the elastomer fails and keep certain vibration isolation performance.

In the above embodiment, the entire escape of the connecting shaft 7 can be avoided. However, if the inclination is too large, the power transmission direction is also shifted. In a preferred embodiment, therefore, the outer side of the retaining cap 8 and the inner side of the sleeve 62 have a transverse gap 84 after the coupling of the retaining cap 8 to the coupling shaft 71. After the transverse gap 84 is zeroed, the outer side surface of the limiting cover 8 contacts with the inner side surface of the first outer sleeve 62, as can be seen in fig. 6, the outer side surface of the limiting cover 8 is convex, and after the convex contacts with the inner side surface of the first outer sleeve 62, the connecting shaft 7 or the first connecting shaft 71 can be transversely limited, so that the connecting shaft 7 or the first connecting shaft 71 cannot be greatly inclined.

Embodiment II is as shown in FIG. 8 to FIG. 10: a method of assembling a vibration isolation system for a marine propulsion system.

Comprises the following steps:

and in the vibration isolator assembly, firstly, an inner sleeve I61 of a vibration isolator I6 and an inner sleeve II 51 of a vibration isolator II 5 are installed on a connecting shaft 7 in an interference fit manner, and a limit cover 8 is installed at one end of the vibration isolator I6 of the connecting shaft 7.

The vibration isolation system is assembled, a connecting shaft 7 and a first vibration isolator 6 extend into the hull outside support frame 3, and a first sleeve 62 of the first vibration isolator 6 is fixed to one end of the hull inside support frame 4; the second sleeve 52 of the second vibration isolator 5 is then fixed to the outer end surface of the hull outside support frame 3 and the end of the connecting shaft 7 is exposed. In this embodiment, the first jacket 62 is bolted to the inner hull support frame 4 via the first flange 64. The second outer jacket 52 is fixed by bolts to fix the second flange 54 to the hull outside support frame 3.

Assembling the propulsion system, sleeving the connecting flange 101 on the exposed end of the connecting shaft 7, and fixing the end cover 103 on the exposed end surface of the connecting shaft 7; the propeller 2 is mounted and fixed on the connection flange 101. The end cover 103 is connected with the exposed end face of the connecting shaft 7 by bolts. The connecting flange 101 and the connecting shaft 7 are connected by spline fit. In order to improve the connection reliability between the connection flange 101 and the connection shaft 7, the connection flange 101 and the connection shaft 7 sleeve joint section are fixedly connected after penetrating through the pin 104. All parts can be fixed by bolts, and the assembly mode is simple and reliable in connection.

Preferably, in the assembling step of the vibration isolation system, when the first sleeve 62 of the first vibration isolator 6 is fixed to one end of the inner support frame 4 of the hull, an access hole 31 is formed in the outer support frame 3 of the hull, and the first sleeve 62 is fixed to one end of the inner support frame 4 of the hull by bolts from the outside of the outer support frame 3 of the hull through the access hole 31. The access opening 31 is provided so that an assembler can be located outside the hull outside support frame 3 to extend an assembling tool into the inner space of the hull outside support frame 3, and a first jacket 62 is fastened to one end of the hull inside support frame 4 by bolts. This makes it possible to assemble a narrow space between the hull outside support frame 3 and the hull inside support frame 4.

Preferably, in the vibration isolator assembling step, a first step 73, a second step 74 and a third step 75 are sequentially formed on the connecting shaft 7 along the axial direction, the first outer sleeve 62 of the first vibration isolator 6 is in interference fit on the first step 73, the second inner sleeve 51 of the second vibration isolator 5 is in interference fit on the third step 75, and then the second outer sleeve 52 of the second vibration isolator 5 is abutted against the outer end surface of the outer support frame 3 after the connecting shaft 7 stretches into the inner side of the outer support frame 3 in the vibration isolator system assembling step. The first step 73 and the third step 75 can accurately position the first outer sleeve 62 and the second outer sleeve 52, so that the second vibration isolator 5 can be conveniently fixed on the outer end face of the ship body outer side supporting frame 3 after the first vibration isolator 6 is fixed.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A vibration isolation system for a marine propulsion system, comprising: the vibration isolator comprises a propelling connector (1) and a vibration isolator II (5), wherein the vibration isolator II (5) comprises an inner sleeve II (51), an outer sleeve II (52) and a rubber body II (53) between the inner sleeve II and the outer sleeve II, the inner sleeve II (51) is connected with one end of the propelling connector (1), the other end of the propelling connector (1) is connected with a propeller (2), and the outer sleeve II (52) is connected with a ship body outer side supporting frame (3).

2. The vibration isolation system of a marine propulsion system of claim 1, wherein: the device also comprises a second connecting shaft (72), wherein one end of the second connecting shaft (72) is connected with the second inner sleeve (51), and the other end of the second connecting shaft is connected with the propelling connector (1).

3. The vibration isolation system of a marine propulsion system of claim 2, wherein: the second outer sleeve (52) is provided with a second flange (54) with a bolt hole, and the second outer sleeve (52) is fixed on the ship body outer side supporting frame (3) through the second flange (54) through bolts.

4. A vibration isolation system for a marine propulsion system according to claim 3, wherein: the propelling connector (1) is a connecting flange (101), one connecting end of the connecting flange (101) and one connecting end of the propeller (2) are provided with a second cavity (102), and the second connecting shaft (72) is sleeved inside the connecting flange (101) and penetrates through the second cavity (102) to be connected with the connecting flange (101) through an end cover (103).

5. The vibration isolation system of a marine propulsion system of claim 4, wherein: the vibration isolator also comprises a first connecting shaft (71), one end of the first connecting shaft (71) and a second connecting shaft (72) are integrally formed into a connecting shaft (7), and the other end of the first connecting shaft is connected with the first vibration isolator (6); the vibration isolator I (6) comprises an inner sleeve I (61) and an outer sleeve I (62), a rubber body I (63) is vulcanized between the inner sleeve I and the outer sleeve I, a connecting shaft I (71) is connected with the inner sleeve I (61), and the outer sleeve I (62) is connected with a ship body inner side supporting frame (4); the first sleeve (62) of the first vibration isolator (6) is provided with a first flange (64) with bolt holes, and the first sleeve (62) is fixed on the inner side supporting frame (4) of the ship body through the first flange (64) through bolts.

6. The vibration isolation system of a marine propulsion system of claim 5, wherein: the inner side opposite to the flange one (64) of the outer sleeve one (62) is provided with a concave plane one (65), the connecting shaft one (71) penetrates through the inner sleeve one (61) and then is connected with the limit cover (8), and the limit cover (8) and the inner side support frame (4) of the ship body are provided with a longitudinal gap one (81); the limiting cover (8) is provided with a convex surface (83) matched with the concave plane I (65), and a longitudinal gap II (82) is formed between the convex surface (83) and the concave plane I (65) after the limiting cover (8) is connected with the connecting shaft I (71).

7. The vibration isolation system of a marine propulsion system of claim 6, wherein: the limit cover (8) is connected with the first connecting shaft (71), and a transverse gap (84) is formed between the outer side surface of the limit cover and the inner side surface of the first outer sleeve (62).

8. A method of assembling a vibration isolation system for a marine propulsion system according to claim 6, comprising the steps of:

the vibration isolator assembly comprises the steps of firstly, mounting an inner sleeve I (61) of a vibration isolator I (6) and an inner sleeve II (51) of a vibration isolator II (5) on a connecting shaft (7) in an interference fit manner, and mounting a limit cover (8) to one end of the vibration isolator I (6) of the connecting shaft (7);

the vibration isolation system is assembled, a connecting shaft (7) and a first vibration isolator (6) extend into the hull outside support frame (3), and a first sleeve (62) of the first vibration isolator (6) is fixed to one end of the hull inside support frame (4); then, a second outer sleeve (52) of the second vibration isolator (5) is fixed to the outer end face of the ship body outer side supporting frame (3) and the end part of the connecting shaft (7) is exposed;

assembling a propulsion system, namely sleeving a connecting flange (101) on the exposed end part of a connecting shaft (7), and fixing an end cover (103) on the exposed end surface of the connecting shaft (7); the propeller (2) is installed and fixed on the connecting flange (101).

9. A method of assembling a vibration isolation system for a marine propulsion system according to claim 8, wherein in the step of assembling the vibration isolation system, when the first sleeve (62) of the first vibration isolator (6) is fixed to the end of the inner support frame (4) of the hull, an access opening (31) is formed in the outer support frame (3) of the hull, and the first sleeve (62) is fixed to the end of the inner support frame (4) of the hull by bolts from the outside of the outer support frame (3) of the hull through the access opening (31).

10. The assembling method of the vibration isolation system of the ship propulsion system according to claim 9, wherein in the vibration isolator assembling step, a step one (73), a step two (74) and a step three (75) are sequentially formed on the connecting shaft (7) along the axial direction, the outer sleeve one (62) of the vibration isolator one (6) is in interference fit with the step one (73), the inner sleeve two (51) of the vibration isolator two (5) is in interference fit with the step three (75), and then the outer sleeve two (52) of the vibration isolator two (5) is abutted against the outer end face of the ship outer support frame (3) after the connecting shaft (7) stretches into the ship outer support frame (3) in the vibration isolator assembling step.