阅读说明：本技术 一种船用艉轴弯曲变形的修复方法 (Method for repairing bending deformation of marine stern shaft ) 是由 邝学军 王国辉 张文全 曾新平 钟诚 刘永生 许煌育 于 2021-05-31 设计创作，主要内容包括：本发明提供一种船用艉轴弯曲变形的修复方法,使用冷压进行逐步矫正艉轴,根据检测的径向跳动量施加压力使所述艉轴逐步发生形变矫直,并避免力度过大使艉轴断裂,可修复变形严重的艉轴(例如最大径向跳动量达10mm),有利于节省成本和修理周期。(The invention provides a method for repairing the bending deformation of a marine stern shaft, which is characterized in that cold pressing is used for gradually correcting the stern shaft, pressure is applied according to the detected radial run-out amount to gradually deform and straighten the stern shaft, the stern shaft is prevented from being broken due to overlarge force, the severely deformed stern shaft (for example, the maximum radial run-out amount reaches 10mm) can be repaired, and the cost and the repair period are saved.)

1. A method for repairing bending deformation of a marine stern shaft is characterized by comprising the following steps:

the method comprises the following steps:

s1: the stern shaft comprises a plurality of shaft sections which are connected in sequence, and the straight shaft section at the middle is taken as a reference section;

s2: measuring the radial runout quantity by taking a plurality of points on a stern shaft adjusting section, wherein the stern shaft adjusting section is a shaft section positioned at two ends of the reference section; comparing the measured radial run-out values of all points of the stern shaft adjusting section with an industry standard value, wherein the industry standard value is the range of the radial run-out values normally used by the stern shaft;

identifying the initial deformation point on the stern shaft: the initial deformation point is the minimum value of the radial runout quantity on each point of the screw shaft adjusting section;

s3: placing the stern shaft on an operation table, wherein the reference section is parallel to the operation table;

marking the maximum value or the position close to the maximum value of the radial runout quantity on each point of the screw shaft adjusting section as a pressure point;

s4: reducing the radial runout of the stern shaft by turns:

(1) according to the radial runout amount, applying pressure to the pressure point, and providing a supporting force opposite to the pressure direction at the initial deformation point to reduce the radial runout amount of the screw shaft;

(2) removing pressure, and detecting the radial runout quantity of each point of the stern shaft adjusting section;

(3) and (3) repeating the step (1) and the step (2) until the radial runout quantity of each point of the stern shaft adjusting section accords with the industry standard value after detection if the radial runout quantity of each point of the stern shaft adjusting section does not accord with the industry standard value.

2. The method for repairing bending deformation of a marine stern shaft according to claim 1, wherein:

s3 further includes: marking the shaft section where the pressure point is located as a maximum deformation shaft section; and rotating the stern shaft until the maximum deformation shaft section is bent towards one side far away from the operating platform.

3. The method for repairing bending deformation of a marine stern shaft according to claim 1, wherein:

in S4, when detecting the radial runout amount of each point of the stern shaft adjusting section, when the radial runout amount of the initial deformation point meets the industry standard value, resetting the initial deformation point at the currently detected minimum value of the radial runout amount on the stern shaft.

4. The method for repairing bending deformation of a marine stern shaft according to claim 1, wherein:

in S2, the number of the initial deformation points is two, and the initial deformation points are respectively close to both ends of the reference segment, and the method for determining the initial deformation points includes: taking the point with the minimum radial runout amount in each shaft section close to one end of the reference section, and marking as an initial deformation point B1; taking the point with the minimum radial runout amount in each shaft section close to the other end of the reference section, and recording the point as an initial deformation point B2;

in S3, the number of the pressure points is two, the two pressure points are respectively close to the two ends of the reference section and are marked as pressure points C1 and C2;

in each shaft segment near one end of the reference segment, the amount of radial runout of the shaft increases in the direction from the initial deformation point B1 to the pressure point C1; in each shaft segment near the other end of the reference segment, the amount of radial runout of the shaft segment increases in the direction from the initial deformation point B2 to the pressure point C2.

5. The method for repairing bending deformation of a marine stern shaft according to claim 4, wherein:

and repairing the shaft section close to one end of the reference section until the radial runout amount meets the industry standard value, and then repairing the shaft section close to the other end of the reference section.

6. The method for repairing bending deformation of a marine stern shaft according to claim 1, wherein:

s4, selecting a pressure shaft frame to apply pressure to the pressure point;

the pressing shaft frame comprises a top plate, a pressing plate, a pressure device and a fixing rod;

the top plate and the pressing plate are placed in parallel, the pressure device is used for applying pressure, one end of the pressure device is fixed with the top plate, and the other end of the pressure device is fixed with the pressing plate;

one surface of the pressure plate, which is far away from the pressure device, is abutted against the screw shaft; one end of the fixed rod is fixed on the operating table;

the top plate and the pressing plate can be detachably fixed with the fixing rod, and the pressing plate can move up and down along the fixing rod;

when the shaft pressing frame is used, the top plate is fixed with the fixed rod, the pressure device works to push the pressure plate to move downwards so as to apply pressure to the pressure point, and the stern shaft is deformed; and then the pressure device is enabled to remove pressure, the pressing plate is fixed with the fixed rod, and the fixing of the top plate and the fixed rod is released.

7. The method for repairing bending deformation of a marine stern shaft according to claim 6, wherein:

the pressing plate comprises two horizontal plates and an arc plate, and the two horizontal plates are respectively positioned at two ends of the arc plate; the horizontal plate is detachably fixed with the fixed rod; the arc of the arc plate faces the direction far away from the pressing plate and is used for being clamped and fixed with the stern shaft.

8. The method for repairing bending deformation of a marine stern shaft according to claim 1, wherein:

in the step S4, a support frame is selected to provide support force for the initial deformation point, the stern shaft is connected with the support frame, and the support frame is arranged on the operating platform; wherein the position of the support frame corresponds to the position of the initial deformation point on the stern shaft;

the supporting frame comprises a supporting plate and a base fixed below the supporting plate; an open slot is formed in the supporting plate, and when the stern shaft is placed on the supporting frame, the open slot corresponds to the position and the shape of the stern shaft.

9. The method for repairing bending deformation of a marine stern shaft according to claim 1, wherein:

in S3, a reference seat is taken and placed between the stern shaft and the operating platform; wherein both ends of the reference section are arranged on the reference seat;

the reference seat comprises an upper cover plate, a lower supporting plate and a reference seat base;

the upper cover plate is provided with an upper cover plate groove, the lower supporting plate is provided with a lower supporting plate groove, the upper cover plate is detachably connected with the lower supporting plate, and when the stern shaft is placed on the reference seat, the upper cover plate groove and the lower supporting plate groove form an accommodating space which is adaptive to the position and the shape of the stern shaft;

the lower supporting plate is fixed at the bottom of the reference seat base, and the reference seat base is arranged on the operating table.

10. The method for repairing bending deformation of a marine stern shaft according to claim 9, wherein:

in S4, after pressure is removed, a rolling shaft bracket is selected to separate the stern shaft from the reference seat; the rolling shaft bracket comprises a shaft supporting plate, a telescopic screw and a shaft bracket base, wherein a shaft supporting plate groove is formed in the shaft supporting plate and is matched with the side surface shape of the stern shaft; one end of the telescopic screw rod is fixed on the shaft bracket base, and the other end of the telescopic screw rod is fixed on the shaft supporting plate; the pedestal base is arranged on the operating platform;

when the pressure applied to the pressure point is removed, the connection between the upper cover plate and the lower supporting plate is released, and the telescopic screw rod is extended, so that the stern shaft is separated from the reference seat.

Technical Field

The invention belongs to the technical field of ship maintenance, and particularly relates to a method for repairing bending deformation of a marine stern shaft.

Background

The stern shaft is positioned at the tail end of the ship middle shaft system structure, one end of the stern shaft is connected with a control system in the cabin, and the other end of the stern shaft is connected with the propeller. The stern shaft has severe working conditions, is easily corroded by seawater, is easily bent and deformed under the action of bending and alternating stress, reduces the propelling efficiency of the ship and influences the normal operation of the ship. The repair method for the stern shaft is usually the flame straightening or the bushing and boring, but for the stern shaft with serious deformation degree, the repair method can not ensure to straighten the middle line of the stern shaft. If cold pressing is used for correction, the difficulty lies in the selection of the datum point, the initial deformation point and the pressure point, and the risk of easy breakage due to overlarge force exists.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a method for repairing the bending deformation of a marine stern shaft, which can repair the stern shaft with serious deformation under cold pressing and is beneficial to saving the cost and the repair period.

The invention is realized by the following technical scheme:

a method for repairing bending deformation of a marine stern shaft comprises the following steps:

s1: the stern shaft comprises a plurality of shaft sections which are connected in sequence, and the straight shaft section at the middle is taken as a reference section; s2: measuring the radial runout quantity by taking a plurality of points on a stern shaft adjusting section, wherein the stern shaft adjusting section is a shaft section positioned at two ends of the reference section; comparing the measured radial runout amount of each point of the stern shaft adjusting section with an industry standard value, wherein the industry standard value is the normal radial runout amount range of the stern shaft; identifying the initial deformation point on the stern shaft: the initial deformation point is the minimum value of the radial runout quantity on each point of the screw shaft adjusting section; s3: placing the stern shaft on an operation table, wherein the reference section is parallel to the operation table; marking the maximum value or the position close to the maximum value of the radial runout quantity on each point of the screw shaft adjusting section as a pressure point; s4: the radial runout of the screw shaft is reduced by times: (1) according to the radial runout amount, applying pressure to the pressure point, and providing a supporting force opposite to the pressure direction at the initial deformation point to reduce the radial runout amount of the screw shaft; (2) removing pressure, and detecting the radial runout quantity of each point of the stern shaft adjusting section; and (3) after detection, if the radial runout amount of each point of the screw shaft adjusting section does not accord with the industry standard value, repeating the steps (1) and (2) until the radial runout amount of each point of the screw shaft adjusting section accords with the industry standard value of the runout amount.

According to the method for repairing the bending deformation of the marine stern shaft, the stern shaft is corrected step by cold pressing, pressure is applied according to the radial run-out amount to enable the stern shaft to deform step by step, the fracture of the stern shaft with overlarge force is avoided, the stern shaft with serious deformation can be repaired (for example, the maximum radial run-out amount reaches 10mm), and the cost and the repair period are saved.

Further, S3 includes: marking the shaft section where the pressure point is located as a maximum deformation shaft section; and rotating the stern shaft until the maximum deformation shaft section is bent towards one side far away from the operating platform. And the screw shaft is rotated to a state suitable for processing, so that downward pressure is conveniently applied to the maximum deformation shaft section, and the screw shaft is subsequently lifted to measure the radial runout amount.

Further, in S4, when detecting the radial run-out amount of each point of the stern shaft adjusting section, when the radial run-out amount of the initial deformation point meets the industry standard value of the run-out amount, resetting the initial deformation point at the currently detected minimum value of the radial run-out amount on the stern shaft. And measuring the radial runout, wherein the position of the initial deformation point changes along with the correction process, and a supporting force is provided below the position of the initial deformation point in time, so that the correction operation at the pressure point is facilitated.

Further, in S2, the number of the initial deformation points is two, and the initial deformation points are respectively close to both ends of the reference segment, and the method for determining the initial deformation points includes: taking the point with the minimum radial runout amount in each shaft section close to one end of the reference section, and marking as an initial deformation point B1; taking the point with the minimum radial runout amount in each shaft section close to the other end of the reference section, and recording the point as an initial deformation point B2; in S3, the number of the pressure points is two, the two pressure points are respectively close to the two ends of the reference section and are marked as pressure points C1 and C2; in each shaft segment near one end of the reference segment, the amount of radial runout of the shaft segment increases in the direction from the initial deformation point B1 to the pressure point C1; in each shaft segment near the other end of the reference segment, the amount of radial runout of the shaft segment increases in the direction from the initial deformation point B2 to the pressure point C2. In the method for confirming the starting point, the pressure is applied to the pressure point while the support is provided for the starting deformation point by confirming the starting deformation point and the pressure point, so that the stern shaft is corrected.

And further, repairing the shaft section close to one end of the reference section until the radial runout amount meets the industry standard value, and then repairing the shaft section close to the other end of the reference section. And the shaft section is maintained in a segmented mode, so that the additional stress generated on the shaft section during maintenance is avoided.

Further, in S4, a pressure shaft segment frame is selected to apply pressure to the pressure point; the shaft pressing section frame comprises a top plate, a pressing plate, a pressure device and a fixing rod; the top plate and the pressing plate are placed in parallel, the pressure device is used for applying pressure, one end of the pressure device is fixed with the top plate, and the other end of the pressure device is fixed with the pressing plate; one surface of the pressure plate, which is far away from the pressure device, is abutted against the screw shaft; one end of the fixed rod is fixed on the operating table; the top plate and the pressing plate can be detachably fixed with the fixing rod, and the pressing plate can move up and down along the fixing rod; when the shaft pressing section frame is used, the top plate and the fixed rod are detachably fixed, the pressure device works to push the pressure plate to move downwards so as to apply pressure to the pressure point, and the stern shaft is deformed; and then the pressure device is enabled to remove pressure, the pressing plate is fixed with the fixed rod, and the fixing of the top plate and the fixed rod is released. And applying pressure at the pressure point through the pressure shaft section frame so as to deform the stern shaft to correct the stern shaft, wherein the pressure device applies pressure to the stern shaft by pushing the pressure plate to move, and the pressure device is fixed through the top plate so as to avoid displacement of the pressure device under the reaction force. When the pressure device removes the pressure, the pressure plate and the fixing rod are fixed to avoid the rebounding of the stern shaft, the fixing of the top plate and the fixing rod is removed, the pressure can be increased on the top plate or the top plate can be moved to avoid the insufficient stroke of the pressure device, and therefore the stern shaft can be continuously pressurized.

Furthermore, the pressing plate comprises two horizontal plates and an arc plate, and the two horizontal plates are respectively positioned at two ends of the arc plate; the horizontal plate is detachably fixed with the fixed rod; the arc of the arc plate faces the direction far away from the pressing plate and is used for being clamped and fixed with the stern shaft. The arc plate is arranged to adapt to the shape of the stern shaft, so that the stress area of the stern shaft is increased.

Further, in S4, a support frame is selected to provide a supporting force for the initial deformation point, the stern shaft is connected to the support frame, and the support frame is placed on the operation table; wherein the position of the support frame corresponds to the position of the initial deformation point on the stern shaft; the supporting frame comprises a supporting plate and a base fixed below the supporting plate; an open slot is formed in the supporting plate, and when the stern shaft is placed on the supporting frame, the open slot corresponds to the position and the shape of the stern shaft. When the pressure point is pressed downwards, the supporting frame provides supporting force for the initial deformation point.

Further, in S3, a reference seat is placed between the stern shaft and the operation table; wherein both ends of the reference section are arranged on the reference seat; the reference seat comprises an upper cover plate, a lower supporting plate and a reference seat base; the upper cover plate is provided with an upper cover plate groove, the lower supporting plate is provided with a lower supporting plate groove, the upper cover plate is detachably connected with the lower supporting plate, and when the stern shaft is placed on the reference seat, the upper cover plate groove and the lower supporting plate groove form an accommodating space which is adaptive to the position and the shape of the stern shaft; the lower supporting plate is fixed at the bottom of the reference seat base, and the reference seat base is arranged on the operating table. When the pressure point is pressed downwards, the reference seat provides an upward supporting force for the reference section so as to maintain the horizontal state of the reference seat; the upper cover plate and the lower supporting plate are detachably connected, and the distance between the upper cover plate and the lower supporting plate can be adjusted according to the sizes of different stern shafts.

Further, in S4, after the pressure is removed, a rolling shaft segment frame is selected to separate the stern shaft from the reference seat; the rolling shaft section frame comprises a shaft section supporting plate, a telescopic screw and a shaft section frame base, and a shaft section supporting plate groove is formed in the shaft section supporting plate and is matched with the side surface shape of the stern shaft; one end of the telescopic screw rod is fixed on the shaft section frame base, and the other end of the telescopic screw rod is fixed on the shaft section supporting plate; the shaft section frame base is arranged on the operating platform; when the pressure applied to the pressure point is removed, the connection between the upper cover plate and the lower supporting plate is released, and the telescopic screw rod is extended, so that the stern shaft is separated from the reference seat. The stern shaft is placed on the shaft section supporting plate, the height of the stern shaft is adjusted through the telescopic screw rod, when the pressure applied to the pressure point is removed, the telescopic screw rod extends and the connection between the upper cover plate and the lower supporting plate is removed, so that the stern shaft is lifted up and separated from the reference seat, the stern shaft is convenient to rotate so as to measure the radial runout amount of the stern shaft, and the pressure subsequently applied to the pressure point is adjusted according to the measured radial runout amount.

For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural view of a stern shaft repair for a ship in embodiment 1.

Fig. 2 is a schematic structural view of a stern shaft for a ship according to embodiment 1.

Fig. 3 is a schematic structural view of a pressure shaft bracket in embodiment 1.

FIG. 4 is a schematic view showing the structure of a support in example 1.

Fig. 5 is a schematic structural view of the reference block in embodiment 1.

Fig. 6 is a schematic structural view of the rolling shaft seat in embodiment 1.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of and not restrictive on the broad invention. It should be further noted that, for convenience of description, only some structures, not all structures, relating to the embodiments of the present invention are shown in the drawings.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for descriptive purposes only to distinguish one element from another, and are not to be construed as indicating or implying relative importance or implying any order or order to the indicated elements. The terms are interchangeable where appropriate. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

Similarly, the terms "fixed" and "connected," as used in the description and claims, are not to be construed as limited to direct connection. Thus, the expression "device a is connected to device B" should not be limited to devices or systems in which device a is directly connected to device B, meaning that there is a path between device a and device B, which may be a path including other devices or tools.

Example 1

The embodiment 1 provides a method for repairing bending deformation of a marine stern shaft, as shown in fig. 1 and 2, which includes the following steps:

s1: the stern shaft 1 comprises a plurality of shaft sections 11 which are connected in sequence, and the straight shaft section 11 at the middle is taken as a reference section 111;

s2: measuring the radial runout quantity by taking a plurality of points on a stern shaft adjusting section, wherein the stern shaft adjusting section is a shaft section positioned at two ends of the reference section; comparing the measured radial runout amount of each point of the stern shaft adjusting section with an industry standard value, wherein the industry standard value is the range of the radial runout amount normally used by the stern shaft 1; the initial deformation point on the stern shaft 1 was confirmed: the initial deformation point is the minimum value of the radial runout quantity on each point of the screw shaft adjusting section which does not accord with the industry standard value;

s3, placing the screw shaft 1 on an operation table 6, wherein the reference section 111 is parallel to the operation table 6;

marking the maximum value or the position close to the maximum value of the radial runout quantity on each point of the screw shaft adjusting section as a pressure point;

s4: the radial runout of the stern shaft 1 is reduced by times: (1) according to the radial runout amount, pressure is applied to the pressure point, and meanwhile supporting force opposite to the pressure direction is provided at the initial deformation point, so that the radial runout amount of the screw shaft 1 is reduced;

(2) removing pressure, and detecting the radial runout quantity of each point of the stern shaft adjusting section;

(3) and (3) repeating the step (1) and the step (2) until the radial runout quantity of each point of the stern shaft adjusting section accords with the industry standard value after detection if the radial runout quantity of each point of the stern shaft adjusting section does not accord with the industry standard value.

According to the method for repairing the bending deformation of the marine stern shaft, the stern shaft 1 is corrected step by cold pressing, pressure is applied according to the radial run-out amount to enable the stern shaft 1 to deform step by step, the stern shaft 1 with overlarge force is prevented from being broken, the stern shaft 1 with serious deformation (such as the stern shaft 1 with the maximum radial run-out amount of 10mm) can be repaired, and cost and repair period are saved. The bending state of the marine screw shaft is the state that the radial runout on the screw shaft 1 exceeds the industry standard value. The industry standard value is the range of the radial runout amount normally used by the stern shaft 1, and the stern shaft is considered to be bending deformation by referring to the national standard CB/T3417-2015 and if the radial runout amount exceeds the national standard CB/T3417-2015.

Preferably, as shown in fig. 1, S3 further includes: marking the shaft section 11 where the pressure point is as a maximum deformation shaft section 112; the stern shaft 1 is rotated until the maximum deformation shaft section 112 bends towards the side away from the operation platform 6. The stern shaft 1 is rotated to a state suitable for processing, so that downward pressure can be conveniently applied to the maximum deformation shaft section 112, and the stern shaft 1 can be lifted up to measure the radial runout amount.

Preferably, in S4, when the radial run-out amount of each point of the stern shaft adjusting section is detected, when the radial run-out amount of the initial deformation point meets the industry standard value, the initial deformation point is reset at the minimum value of the currently detected radial run-out amount on the stern shaft 1. The radial runout is measured, the position of the initial deformation point changes along with the correction process, the supporting force is provided below the position of the initial deformation point in time, and the correction operation at the pressure point is facilitated.

As shown in fig. 1 and 2, the two end points of the reference segment 111 are denoted as a1 and a2, respectively. Preferably, as shown in fig. 1 and 2, in S2, the number of the initial deformation points is two, and the initial deformation points are respectively close to the two ends of the reference segment 111, and the method for identifying the initial deformation points includes: taking the point with the minimum radial runout quantity in each shaft section 11 close to one end of the reference section 111, and recording the point as an initial deformation point B1; taking the point with the minimum radial runout quantity in each shaft section 11 close to the other end of the reference section 111, and recording the point as an initial deformation point B2; as shown in fig. 1 and 2, in S3, the number of pressure points is two, and the two pressure points are respectively close to the two ends of the reference segment 111 and are marked as pressure points C1 and C2; in each shaft segment 11 near one end of the reference segment 111, the amount of radial runout of the shaft segment 11 increases in the direction from the initial deformation point B1 to the pressure point C1; in each shaft segment 11 near the other end of reference segment 111, the amount of radial runout of shaft segment 11 increases in the direction from the initial deformation point B2 to pressure point C2. This is a method of identifying the initial deformation point, by identifying the initial deformation point and the pressure point, applying pressure to the pressure point while providing support for the initial deformation point, so that the stern shaft 1 is corrected.

Preferably, the shaft segment 11 near one end of the reference segment 111 is repaired until the amount of radial run-out meets the industry standard, and then the shaft segment 11 near the other end of the reference segment 111 is repaired. And the sectional maintenance is carried out, so that the additional stress on the shaft section 11 during the simultaneous maintenance is avoided.

Preferably, in S3, the radial run-out of the stern shaft 1 is detected, and when the radial run-out of the starting deformation points B1 and B2 meet the industry standard value, the starting deformation point is reset at the minimum value of the currently detected radial run-out of the stern shaft 1. The radial runout is measured, the position of the initial deformation point is changed along with the correction process, and the supporting force is provided below the positions of the initial deformation points B1 and B2 in time, so that the correction operation at the pressure point is facilitated.

Preferably, as shown in fig. 1 and 3, a pressure shaft segment frame 2 is selected in S4 to apply pressure to the pressure points C1 and C2; the shaft pressing section frame 2 comprises a top plate 21, a pressing plate 22, a pressure device 23 and a fixing rod 24; the top plate 21 and the pressing plate 22 are placed in parallel, the pressure device 23 is used for applying pressure, one end of the pressure device 23 is fixed with the top plate 21, and the other end of the pressure device 23 is fixed with the pressing plate 22; one surface of the pressure plate 22 far away from the pressure device 23 is abutted against the screw shaft 1; one end of the fixing rod 24 is fixed on the operation table 6;

the top plate 21 and the pressing plate 22 are both detachably fixed with the fixing rod 24, and the pressing plate 22 can move up and down along the fixing rod 24;

when the shaft pressing section frame 2 is used, the top plate 21 is fixed with the fixing rod 24, the pressure device 23 works under the force, and pushes the pressure plate 22 to move downwards so as to apply pressure to the pressure point, so that the screw shaft 1 is deformed; then, the pressure device 23 is released from the pressure, the pressing plate 22 is fixed to the fixing rod 24, and the fixing of the top plate 21 to the fixing rod 24 is released. The pressure is applied at the pressure point through the pressure shaft section frame 2, so that the screw shaft 1 is deformed to correct the screw shaft 1, wherein the pressure device 23 applies pressure to the screw shaft 1 by pushing the pressure plate 22 to move, and the pressure device 23 is fixed through the top plate 21, so that the pressure device 23 is prevented from generating displacement under the reaction force; when the pressure device 23 removes the pressure, the pressing plate 22 is fixed with the fixing rod 24 to avoid the recoil of the stern shaft 1, at this time, the fixing of the top plate 21 and the fixing rod 24 is removed, the pressure can be increased on the top plate 21 or the top plate 21 can be moved to avoid the insufficient stroke of the pressure device 23, and the stern shaft 1 can be continuously pressurized. The pressure device 23 may be a hydraulic pump.

More preferably, as shown in fig. 3, the pressing plate 22 includes two horizontal plates 221 and an arc plate 222, and the two horizontal plates 221 are respectively located at two ends of the arc plate 222; the horizontal plate 221 is used for being detachably fixed with the fixing rod 24; the arc plate 222 faces away from the pressure plate 22 and is engaged with and fixed to the stern shaft 1. The circular arc plate 222 is arranged to adapt to the shape of the stern shaft 1, and the stress area of the stern shaft 1 is increased.

Preferably, as shown in fig. 1 and 4, the support frame 3 is selected to provide a supporting force for the initial deformation point in S4, the stern shaft 1 is connected with the support frame 3, and the support frame 1 is placed on the operation table 6; wherein the position of the support frame 3 corresponds to the position of the starting deformation points B1 and B2 on the stern shaft 1; the support frame 3 includes a support plate 31 and a base 32 fixed below the support plate 31; the support plate 31 is provided with an open slot 311, and when the stern shaft 1 is placed on the support frame 3, the open slot 311 corresponds to the stern shaft 1 in position and shape. The support frame 3 provides support for the initial deformation points B1 and B2 when the pressure points are subjected to C1 and C2 pressures.

Preferably, as shown in fig. 1 and 5, in S3, the reference seat 4 is placed between the stern shaft 1 and the operation table 6; wherein both ends a1 and a2 of the reference segment 111 are placed on the reference seat 4; the reference seat 4 comprises an upper cover plate 41, a lower supporting plate 42 and a reference seat base 43; the upper cover plate 41 is provided with an upper cover plate groove 411, the lower support plate 42 is provided with a lower support plate groove 422, the upper cover plate 41 is detachably connected with the lower support plate 42, and when the stern shaft 1 is placed on the reference seat 4, the upper cover plate groove 411 and the lower support plate groove 422 form an accommodating space which is adaptive to the position and the shape of the stern shaft 1; the lower blade 42 is fixed to the bottom of the reference base 43, and the reference base 43 is placed on the operation table 6. When the pressure points C1 and C2 are pressed downward, the reference seat 4 provides an upward supporting force for the reference section 111 to maintain the horizontal state of the reference seat 4; the upper cover plate 41 and the lower support plate 42 are detachably connected, and the distance between the upper cover plate 41 and the lower support plate 42 can be adjusted according to the sizes of different stern shafts 1.

Preferably, as shown in fig. 1 and 6, in S4, after the pressure is removed, the rolling shaft section frame 5 is selected to separate the stern shaft 1 from the reference seat 4; the rolling shaft section frame 5 comprises a shaft section supporting plate 51, a telescopic screw 52 and a shaft section frame base 54, wherein a shaft section supporting plate groove 511 is formed in the shaft section supporting plate 51 and is matched with the side shape of the stern shaft 1; one end of the telescopic screw rod 52 is fixed on the shaft section frame base 54, and the other end is fixed on the shaft section supporting plate 51; the shaft section frame base 54 is arranged on the operation table 6; when the pressure applied to the pressure points is removed, the upper cover plate 41 is disconnected from the lower support plate 42 and the telescopic screw 52 is extended to separate the stern shaft 1 from the reference frame 4. The stern shaft 1 is placed on the shaft section supporting plate 51, the height of the stern shaft 1 is adjusted through the telescopic screw rod 52, when the pressure applied to a pressure point is removed, the telescopic screw rod 52 extends and the connection between the upper cover plate 41 and the lower supporting plate 42 is removed, so that the stern shaft 1 is lifted, the stern shaft 1 is separated from the reference seat 4, the stern shaft 1 is convenient to rotate to measure the radial runout amount of the stern shaft 1, and the pressure subsequently applied to the pressure point is adjusted according to the measured radial runout amount. In a specific embodiment, the number of the rolling shaft segment frames is two, the rolling shaft segment frames are respectively close to the two reference seats, two force application points are provided for the stern shaft, and an upward force is provided while the stern shaft is kept in a horizontal state and ascends.

More preferably, as shown in fig. 6, the rolling shaft segment support 511 further includes two rotating members 53, and the two rotating members 53 are respectively fixed to both ends of the shaft segment supporting plate 51. When the stern shaft 1 is placed on the shaft section supporting plate 51, the rotating member 53 rotates to drive the stern shaft 1 to rotate, which is convenient for measuring the radial runout of the stern shaft 1.

As shown in fig. 6, a magnetic base 7 and a dial indicator 8 are arranged near the operation table 6, so that the dial indicator 8 is in contact with the outer surface of the stern shaft 1 and keeps vertical, the dial indicator 8 is fixed on the magnetic base 7, the magnetic base 7 is used for keeping the dial indicator 8 in a horizontal state, the stern shaft 1 is slowly and uniformly rotated for a circle, and the reading of the dial indicator 8 is recorded, so that the radial run-out is measured.

And (4) carrying out nondestructive inspection after the stern shaft 1 is repaired.

The present invention is not limited to the above-described embodiments, and various modifications and variations of the present invention are intended to be included within the scope of the claims and the equivalent technology of the present invention if they do not depart from the spirit and scope of the present invention.