A method for aligning a marine main engine with an intermediate support and a flexible coupling.

Abstract

This invention relates to a method for aligning and detecting the ship's main engine and intermediate support with a flexible coupling. The method includes detecting the axial distance deviation, displacement deviation, and surface deviation between the main engine and the intermediate support. The axial distance deviation is the deviation between the actual and theoretical axial distance between the main engine flywheel and the flange end of the intermediate support. The surface deviation is the parallelism deviation between the end face of the main engine flywheel and the end face of the flange end of the intermediate support. The displacement deviation is the coaxiality deviation between the end face of the main engine flywheel and the end face of the flange end of the intermediate support. Alignment is considered complete when the axial distance deviation, displacement deviation, and surface deviation all meet the requirements. This invention allows for alignment adjustment between the ship's main engine and intermediate support to meet the installation accuracy requirements of the flexible coupling, and also enables alignment detection between the main engine and intermediate support, allowing for timely monitoring of the main engine's alignment status.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding, and more specifically to a method for aligning and detecting the ship's main engine and intermediate support with a flexible coupling. Background Technology

[0002] During operation, a ship's main engine generates periodically varying unbalanced forces and torques. These forces and torques, transmitted to the hull, cause vibrations in other equipment and generate vibration noise, leading to fatigue damage to equipment and the hull structure, and negatively impacting the ship's acoustic stealth. To address this issue, vibration isolators are widely used in the installation of ship main engines to isolate the excitation forces generated by the engine's vibrations. Vibration isolators primarily consist of rubber blocks. These rubber blocks exhibit creep characteristics, and with increasing operating time, they can affect the alignment of the main engine, thereby altering the operating state of the flexible coupling.

[0003] The flexible coupling is installed at the output end of the main unit. Its function is to effectively transmit the torque output by the main unit, reduce vibration and impact during the transmission process, compensate for the center displacement between the main unit and the intermediate support caused by vibration and impact, and play a role in vibration reduction and noise reduction, thereby protecting the main unit, intermediate support and the reliability of the entire transmission device.

[0004] Existing technologies, such as the marine propulsion system disclosed in CN115325137A, include a coupling between the main engine and the propeller shaft; other existing technologies, such as a quick installation method for a high-elasticity coupling disclosed in CN114132856A, disclose a method for installing the high-elasticity coupling by means of a slide rail.

[0005] While flexible couplings can compensate for center displacement between the main unit and intermediate support caused by vibration and impact, this displacement cannot exceed their design limits. Typically, the alignment detection device between the main unit and intermediate support is temporarily constructed from materials such as channel steel, angle iron, and pipes. This results in relatively poor strength, low measurement accuracy, and the inability to remeasure the three-dimensional dimensions after the flexible coupling is installed. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a method for aligning and detecting the ship's main engine and intermediate support with a flexible coupling. This method enables precise installation of the flexible coupling and allows for monitoring the alignment status of the main engine and intermediate support after installation, ensuring the flexible coupling operates as designed.

[0007] The technical objective of this invention is achieved through the following technical solution:

[0008] A method for aligning a ship's main engine and intermediate support with a flexible coupling, the method including axial distance deviation detection between the main engine and the intermediate support, displacement deviation detection between the main engine and the intermediate support, and crack surface deviation detection;

[0009] Axial distance deviation is the deviation between the actual and theoretical axial distance between the main unit flywheel and the flange end of the intermediate support.

[0010] Crack surface deviation is the parallelism deviation between the end face of the main flywheel of the main unit and the end face of the flange end of the intermediate support.

[0011] Displacement deviation is the coaxiality deviation between the end face of the main unit flywheel and the end face of the flange end of the intermediate support.

[0012] When the axial distance deviation, displacement deviation, and crack surface deviation all meet the requirements, the alignment between the ship's main engine and intermediate support with the flexible coupling meets the requirements.

[0013] Furthermore, when performing axial distance deviation detection, the distance between the main unit flywheel and the end face of the flange is measured and recorded as L. The theoretical distance between the main unit flywheel and the end face of the flange is L0. The axial distance deviation is recorded as △L, where △L = L - L0.

[0014] Furthermore, the distance between the end face of several sets of main engine flywheels and the end face of the flange is measured by rotating the main engine flywheel, and the average distance is calculated as L.

[0015] Furthermore, during the crack surface deviation detection, the distance changes between the end face of the main engine flywheel and the end face of the flange are measured for several groups. For each group of distance changes, the distance changes between the end face of the main engine flywheel and the end face of the flange at two relative positions are collected and denoted as W. n n = 1, 2, 3, ... n, and the crack deviation is denoted as △W;

[0016]

[0017] Where d1 is the diameter of the flexible coupling on the side closest to the main flywheel, and d2 is the diameter at the end face of the flange where the displacement deviation is measured.

[0018] Furthermore, during displacement deviation detection, the axial deviation between the main engine flywheel and the flange end is measured in several sets, and denoted as R. n n = 1, 2, 3, ... n, each group of axis deviation is measured at two relative positions; displacement deviation is denoted as ΔR;

[0019]

[0020] Furthermore, when performing axial distance deviation detection, an axial distance detection device is used for detection. The axial distance detection device includes a connecting plate, a longitudinal frame, a transverse frame, and a telescopic rod. One end of the longitudinal frame is connected to the connecting plate, and the other end of the longitudinal frame is perpendicularly connected to one end of the transverse frame. The telescopic rod is installed at the other end of the transverse frame and extends along the length of the transverse frame. The axial distance detection device is installed on the back end face of the flange end near the edge through the connecting plate. The length of the telescopic rod is adjusted so that the end of the telescopic rod abuts against the end face of the main flywheel.

[0021] The actual axial distance between the main flywheel and the flange end is calculated by subtracting the thickness of the flange end and the thickness of the longitudinal frame from the distance between the telescopic rod and the end of the main flywheel. The main flywheel is rotated to measure several sets of actual distances, and the average value of the measured sets of actual distances is calculated as L.

[0022] Furthermore, when performing crack surface deviation detection, a dial indicator and a detection bracket are used. The detection bracket includes a connecting base plate, a transverse extension rod, a longitudinal extension rod, and a dial indicator mounting rod. One end of the transverse extension rod is vertically fixed to the connecting base plate, and the other end of the transverse extension rod is vertically connected and fixed to one end of the longitudinal extension rod. The other end of the longitudinal extension rod is vertically connected to one end of the dial indicator mounting rod, which is set parallel to the transverse extension rod. The detection bracket is connected to the end face of the main flywheel near the edge via the connecting base plate. The first dial indicator is mounted on the dial indicator mounting rod, with the measuring head of the first dial indicator against the end face of the flange. The reading of the first dial indicator is read. Several sets of first dial indicator measurement data are measured by rotating the main flywheel. The difference between the readings of the first dial indicator at relative positions is W. n .

[0023] Furthermore, during displacement deviation detection, a second dial indicator and a detection bracket are used. The detection bracket includes a connecting base plate, a transverse extension rod, a longitudinal extension rod, and a dial indicator mounting rod. One end of the transverse extension rod is vertically fixed to the connecting base plate, and the other end of the transverse extension rod is vertically connected and fixed to one end of the longitudinal extension rod. The other end of the longitudinal extension rod is vertically connected to one end of the dial indicator mounting rod, which is set parallel to the transverse extension rod. The detection bracket is connected to the end face of the main flywheel near the edge via the connecting base plate. The second dial indicator is mounted on the dial indicator mounting rod, with its measuring head against the side of the flange end, and the reading of the second dial indicator is taken. Several sets of second dial indicator measurement data are measured by rotating the main flywheel. The difference between the readings of the second dial indicator at relative positions is R. n .

[0024] Furthermore, the crack surface deviation and displacement deviation are simultaneously detected using a first dial indicator, a second dial indicator, and a detection bracket;

[0025] The testing bracket includes a connecting base plate, a horizontal extension rod, a vertical extension rod, and a dial indicator mounting rod; one end of the horizontal extension rod is vertically fixed to the connecting base plate, the other end of the horizontal extension rod is vertically connected and fixed to one end of the vertical extension rod, the other end of the vertical extension rod is vertically connected to one end of the dial indicator mounting rod, and the dial indicator mounting rod is set parallel to the horizontal extension rod.

[0026] Mount both the first and second dial indicators on the dial indicator mounting rod, with the measuring head of the first dial indicator against the end face of the flange and the measuring head of the second dial indicator against the side of the flange. Read the readings of the first and second dial indicators respectively. Rotate the main unit flywheel to measure several sets of readings of the first and second dial indicators. The difference between the readings of the first dial indicator at relative positions is W. n The difference between the readings of the second percentile at the relative positions is R. n .

[0027] Compared with the prior art, the beneficial effects of the present invention are that the alignment detection of the ship's main engine and intermediate support with flexible coupling is performed by the method of the present invention. Based on the detection results, the alignment adjustment between the ship's main engine and the intermediate support can be realized to meet the installation accuracy of the flexible coupling. After the ship's main engine is put into use, the alignment detection of the ship's main engine and intermediate support can also be realized by using this method to keep track of the alignment status of the main engine in a timely manner and ensure that the flexible coupling works in the design state. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the axial distance detection device in this invention.

[0029] Figure 2 This is a diagram showing the usage status of the axial distance detection device in this invention.

[0030] Figure 3 This is a schematic diagram of the axial distance detection device in this invention.

[0031] Figure 4 This is a schematic diagram of the first dial indicator installed on the testing bracket in this invention.

[0032] Figure 5 This is a schematic diagram of measurement using a dial indicator in this invention.

[0033] Figure 6 This is a schematic diagram of the positions of d1 and d2 in this invention.

[0034] Figure 7 This is a schematic diagram of the second dial indicator installed on the testing bracket in this invention.

[0035] Figure 8 This is a schematic diagram of the measurement using a second dial indicator in the invention.

[0036] Figure 9 This is a schematic diagram illustrating the simultaneous use of the first and second percentile gauges in this invention.

[0037] Figure 10 A schematic diagram of the axial distance detection device after the flexible coupling is installed in this embodiment of the invention.

[0038] Figure 11 This is a schematic diagram of the installation of the testing bracket after the flexible coupling is installed in an embodiment of the present invention.

[0039] Figure 12 This is a schematic diagram of axial distance deviation measurement in the installation state of the flexible coupling in an embodiment of the present invention.

[0040] In the diagram, 1. Connecting plate; 2. Longitudinal frame; 3. Transverse frame; 4. Fixed rod; 5. Moving rod; 6. Locking bolt; 7. Flange end; 8. Main unit flywheel; 9. Connecting base plate; 10. Transverse extension rod; 11. Longitudinal extension rod; 12. Dial indicator mounting rod; 13. First dial indicator; 14. Second dial indicator; 15. Flexible coupling. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to specific embodiments:

[0042] A method for aligning and detecting the ship's main engine and intermediate support with a flexible coupling is disclosed. The main engine flange of the ship's main engine is connected to the flange end of the intermediate support through the flexible coupling, so that the power output of the ship's main engine can be transmitted to the ship's shafting system through the flexible coupling and the intermediate support. In order to ensure the installation accuracy of the flexible coupling, the ship's main engine and the intermediate support need to be aligned before the flexible coupling is installed.

[0043] The method includes axial distance deviation detection between the main unit and the intermediate support, displacement deviation detection between the main unit and the intermediate support, and crack surface deviation detection;

[0044] Axial distance deviation is the deviation between the actual and theoretical axial distance between the main unit flywheel and the flange end of the intermediate support.

[0045] Crack surface deviation is the parallelism deviation between the end face of the main flywheel of the main unit and the end face of the flange end of the intermediate support.

[0046] Displacement deviation is the coaxiality deviation between the end face of the main unit flywheel and the end face of the flange end of the intermediate support.

[0047] When the axial distance deviation, displacement deviation, and crack surface deviation all meet the requirements, the alignment between the ship's main engine and intermediate support with the flexible coupling meets the requirements.

[0048] When performing axial distance deviation testing, the distance between the flywheel of the main unit and the end face of the flange is recorded as L, the theoretical distance between the flywheel of the main unit and the end face of the flange is L0, and the axial distance deviation is recorded as △L, △L=L-L0.

[0049] Preferably, the distance between the end face of the main engine flywheel and the end face of the flange is measured by rotating the main engine flywheel and the average distance is calculated as L.

[0050] Furthermore, to facilitate measurement, this embodiment utilizes an axial distance detection device for detection.

[0051] like Figure 1 As shown, the axial distance detection device includes a connecting plate 1, a longitudinal frame 2, a transverse frame 3, and a telescopic rod; one end of the longitudinal frame 2 is connected to the connecting plate 1, and the other end of the longitudinal frame 2 is perpendicularly connected to one end of the transverse frame 3. The telescopic rod is installed at the other end of the transverse frame 3 and extends along the length direction of the transverse frame 3.

[0052] In this embodiment, the telescopic rod includes a fixed rod 4 and a movable rod 5. One end of the fixed rod 4 is fixed to the end of the transverse frame 3. The movable rod 5 is provided with a telescopic adjustment hole corresponding to the fixed rod 4. The other end of the fixed rod 4 is movably inserted into the telescopic adjustment hole. The length of the telescopic rod is adjusted by changing the length of the fixed rod 4 inserted into the telescopic adjustment hole. A threaded hole communicating with the telescopic adjustment hole is provided on the side wall of the telescopic adjustment hole. A locking bolt 6 is installed in the threaded hole. The length of the telescopic rod is fixed by the locking bolt pressing against the fixed rod.

[0053] When passing through the axial detection device, such as Figure 2 As shown, the axial distance detection device is installed on the end face of the flange end 7 near the edge via a connecting plate 1. The connecting plate 1 is bolted to the end face of the flange end 7. More specifically, the connecting plate 1 is attached to the back end face of the flange end 7. The length of the telescopic rod is adjusted so that the end of the telescopic rod abuts against the end face of the main flywheel 8. The distance between the end of the telescopic rod abutting against the main flywheel and the longitudinal frame is measured, minus the thickness of the flange end and the thickness of the longitudinal frame, as the actual axial distance between the main flywheel and the flange end. The main flywheel is rotated to measure several sets of actual distances, and the average value of the calculated sets of actual distances is taken as L.

[0054] In this embodiment, as Figure 3As shown, the distance between the outer side of the longitudinal frame 2 and the end of the moving rod 5 is X, the thickness of the flange end 7 is D, and the thickness of the longitudinal frame 2 is Z. Therefore, the actual axial distance between the main flywheel 8 and the flange end 7 is XDZ. When only one set of actual distances is measured, L = XDZ, and correspondingly, ΔL = L - L0 = XDZ - L0. When several sets of actual distances are measured by rotating the main flywheel, the average value of all the calculated actual distances is used as L to calculate ΔL = L - L0.

[0055] In this embodiment, the output shaft of the ship's main engine is driven to rotate by a turning gear, thereby rotating the main engine flywheel. Measurements are taken every 90° to obtain four sets of data. The average value of these four sets of data is calculated as L to calculate the axial distance deviation.

[0056] During crack surface deviation detection, the distance change between the end face of the main engine flywheel and the end face of the flange is measured for several groups. For each group of distance changes, the distance change between the end face of the main engine flywheel and the end face of the flange is collected at two relative positions and denoted as W. n n = 1, 2, 3, ... n, and the crack deviation is denoted as △W;

[0057]

[0058] Where d1 is the diameter of the flexible coupling on the side closest to the main flywheel, and d2 is the diameter at the end face of the flange where the displacement deviation is measured.

[0059] For ease of testing, the first dial indicator 13 and a testing bracket are used; the testing bracket is as follows: Figure 4 As shown, the testing bracket includes a connecting base plate 9, a transverse extension rod 10, a longitudinal extension rod 11, and a dial indicator mounting rod 12. One end of the transverse extension rod 10 is vertically fixed to the connecting base plate 9, and the other end of the transverse extension rod 10 is vertically connected and fixed to one end of the longitudinal extension rod 11. The other end of the longitudinal extension rod 11 is vertically connected to one end of the dial indicator mounting rod 13, which is parallel to the transverse extension rod 10. In use, as... Figure 5 As shown, the testing bracket is connected to the end face of the main flywheel near the edge via the connecting base plate 9. Bolt holes for mounting a flexible coupling are provided on the end face of the main flywheel 8. The connecting base plate 9 is fixed to the bolt holes on the end face of the main flywheel using bolts. The first dial indicator 13 is mounted on the dial indicator mounting rod 13, with the measuring head of the first dial indicator 13 abutting against the back end face of the flange end 7. The reading of the first dial indicator is then read. Several sets of the first dial indicator measurement data are measured by rotating the main flywheel. The difference between the readings of the first dial indicator at relative positions is W. n The first and second dial indicators are common types of dial indicators, mainly composed of a measuring head and a dial. The terms "first" and "second" are used only for distinction and are not used to limit the type of dial indicator.

[0060] In this embodiment, after the first dial indicator and the testing bracket are installed, the output shaft of the ship's main engine is rotated using a turning device, which drives the main engine flywheel to rotate. During the rotation of the main engine flywheel, the measuring head of the first dial indicator moves along a circular trajectory against the back end face of the flange. In this embodiment, the main engine flywheel pauses once every 90° rotation to take a reading of the first dial indicator, resulting in a total of four dial indicator readings, denoted as a, b, c, and e. Among them, a and c are the readings of the first dial indicator at relative positions as the first group, and b and e are the readings of the first dial indicator at relative positions as the second group. Then W1 = ac, W2 = be, and thus we get:

[0061]

[0062] d1 and d2 are as follows Figure 6 As shown, d1 is the diameter of the flexible coupling 15 near the flywheel 8 of the main unit, and d2 is the diameter of the circular trajectory formed by the measuring head of the first dial indicator along the end face of the flange during displacement deviation detection.

[0063] During displacement deviation detection, the axial deviation between the main engine flywheel and the flange end is measured in several sets, and denoted as R. n n = 1, 2, 3, ... n, each group of axis deviation is measured at two relative positions; displacement deviation is denoted as ΔR;

[0064]

[0065] For ease of measurement, a second dial indicator and a testing stand are used. The testing stand has the same structure as the one described above. When using it, as follows... Figure 7 As shown, the testing bracket is connected to the end face of the main engine flywheel 8 near the edge via the connecting base plate 9. The installation of the testing bracket is the same as when performing crack deviation testing. The second dial indicator 14 is installed on the dial indicator mounting rod 12, so that the measuring head of the second dial indicator 14 abuts against the side of the flange end 7, and the reading of the second dial indicator 14 is read. The output shaft of the ship's main engine is rotated by the turning device, causing the main engine flywheel to rotate. The second dial indicator reading is taken once every 90° rotation, resulting in a total of four dial indicator readings, denoted as e, f, m, and n. The measurement positions when reading e and m are in relative positions are used as the first set of data, and the measurement positions when reading f and n are in relative positions are used as the second set of data. R1 = em, R2 = fn; then

[0066] In one embodiment, since the first dial indicator 13 and the second dial indicator 14 use the same detection bracket structure and are located close to each other, the first dial indicator 13 and the second dial indicator 14 can be installed on the detection bracket simultaneously to perform crack surface deviation detection and displacement deviation detection at the same time. Figure 9 As shown.

[0067] In one embodiment, after the flexible coupling 15 is installed and the main engine has been in use for a period of time, the alignment test between the main engine and the intermediate support can be performed again using the above method. The difference is that at this time, the flexible coupling 15 is located between the main engine flange 8 and the flange end 7. It is necessary to remove some of the bolts on the main engine flange 8 and the flange end 7 used to connect the flexible coupling to install the test bracket and the axial distance testing device. Figure 10 and Figure 11 As shown, due to the presence of the flexible coupling, when measuring different positions, the ship's main engine rotates while the flexible coupling and intermediate support rotate together. Therefore, when measuring different positions, the installation and testing bracket and axial distance testing device are installed in different positions instead of rotating the machine to different positions for measurement.

[0068] Taking axial distance deviation measurement as an example, such as Figure 12 As shown, with the coupling installed, the distance between the outer side of the longitudinal frame 2 and the end of the moving rod 5 is X, the thickness of the flange end 7 is D, and the thickness of the longitudinal frame 2 is Z. Therefore, the actual axial distance between the main flywheel 8 and the flange end 7 is XDZ. When only one set of actual distances is measured, L = XDZ, and correspondingly, ΔL = L - L0 = XDZ - L0. When several sets of actual distances are measured by rotating the main flywheel, the average value of all the calculated actual distances is used as L to calculate ΔL = L - L0.

[0069] This embodiment is merely a further explanation of the present invention and is not intended to limit the present invention. Those skilled in the art can make non-inventive modifications to this embodiment as needed after reading this specification, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for centering detection of a marine main engine with an elastic coupling and an intermediate support, characterized in that, The method comprises axial distance deviation detection between the main engine and the intermediate support, displacement deviation detection between the main engine and the intermediate support, and crack surface deviation detection; The axial distance deviation is the deviation between the actual distance and the theoretical distance in the axial direction between the main engine flywheel of the main engine and the flange end of the intermediate support; The crack surface deviation is the parallelism deviation of the end surface of the main flywheel of the main machine and the end surface of the flange end of the intermediate support. When the crack surface deviation is detected, the distance changes between the end surface of the main flywheel and the end surface of the flange end of several groups of main flywheels are measured. The distance changes between the end surface of the main flywheel and the end surface of the flange end at two opposite positions in each group are collected, denoted as , n = 1, 2, 3,... n, and the crack surface deviation is denoted as ΔW. ； wherein, D is the diameter of the elastic coupling near the flywheel side of the main machine, D is the diameter of the measurement position at the end face of the flange end when detecting displacement deviation. The displacement deviation is the coaxiality deviation between the end surface of the main engine flywheel of the main engine and the end surface of the flange end of the intermediate support; When the axial distance deviation, the displacement deviation and the crack surface deviation all meet the requirements, the centering of the main engine with the intermediate support with the elastic coupling meets the requirements.

2. The method for centering detection of a marine main engine with an elastic coupling and an intermediate support according to claim 1, characterized in that, When the axial distance deviation is detected, the distance between the flywheel of the main engine and the end face of the flange end is measured as L, the theoretical distance between the flywheel of the main engine and the end face of the flange end is , and the axial distance deviation is .

3. The method for centering detection of a marine main engine with an elastic coupling and an intermediate support according to claim 2, characterized in that, The distance between the end surface of the main engine flywheel and the end surface of the flange end is measured and the average distance is calculated as L.

4. The method for centering detection of a marine main engine with an elastic coupling and an intermediate support according to claim 3, characterized in that, When displacement deviation is detected, the axial center deviation between the main engine flywheel and the flange end of several groups is measured, denoted as , n = 1, 2, 3,... n, the axial center deviation at two relative positions of each group is measured; the displacement deviation is denoted as ΔR; 。 5. The method for detecting the alignment of a marine engine and an intermediate support with an elastic coupling according to claim 3, characterized in that, When the axial distance deviation detection is performed, the axial distance detection device is used for detection, which comprises a connecting plate, a longitudinal frame, a transverse frame and an extension rod; one end of the longitudinal frame is connected with the connecting plate, the other end of the longitudinal frame is connected perpendicularly with one end of the transverse frame, and the extension rod is installed at the other end of the transverse frame and extends along the length direction of the transverse frame; the axial distance detection device is installed on the back end surface of the flange end close to the edge through the connecting plate, the length of the extension rod is adjusted so that the end of the extension rod abuts against the end surface of the main engine flywheel; The distance between the end of the extension rod abutting against the main engine flywheel and the longitudinal frame is measured, and the thickness of the flange end and the thickness of the longitudinal frame are subtracted as the actual distance in the axial direction between the main engine flywheel and the flange end; the actual distance is measured for several groups, and the average value of the actual distances of the several groups is calculated as L.

6. The method for detecting the alignment of a marine engine and an intermediate support with an elastic coupling according to claim 4, characterized in that, When the split face deviation is detected, the detection is performed by means of the first dial gauge and the detection support, the detection support comprising a connecting seat plate, a transverse extension rod, a longitudinal extension rod and a dial gauge mounting rod; one end of the transverse extension rod is fixed perpendicularly on the connecting seat plate, the other end of the transverse extension rod is connected and fixed perpendicularly with one end of the longitudinal extension rod, the other end of the longitudinal extension rod is connected perpendicularly with one end of the dial gauge mounting rod, and the dial gauge mounting rod is arranged parallel to the transverse extension rod; the detection support is connected to the position close to the edge of the end surface of the main machine flywheel through the connecting seat plate, the first dial gauge is mounted on the dial gauge mounting rod, so that the measuring head of the first dial gauge abuts against the end surface of the flange end, and the reading of the first dial gauge is read; the main machine flywheel is rotated to measure a plurality of groups of first dial gauge measurement data, and the difference of the readings of the first dial gauge at the relative positions is .

7. The method for detecting the alignment of a marine engine and an intermediate support with an elastic coupling according to claim 4, characterized in that, When the displacement deviation is detected, the detection is performed by means of the second dial gauge and the detection support, the detection support comprising a connecting seat plate, a transverse extension rod, a longitudinal extension rod and a dial gauge mounting rod; one end of the transverse extension rod is fixed perpendicularly on the connecting seat plate, the other end of the transverse extension rod is connected and fixed perpendicularly with one end of the longitudinal extension rod, the other end of the longitudinal extension rod is connected perpendicularly with one end of the dial gauge mounting rod, and the dial gauge mounting rod is arranged in parallel with the transverse extension rod; the detection support is connected to the position close to the edge of the end surface of the main machine flywheel through the connecting seat plate, the second dial gauge is mounted on the dial gauge mounting rod, so that the measuring head of the second dial gauge abuts against the side surface of the flange end, and the reading of the second dial gauge is read; the main machine flywheel is rotated to measure a plurality of groups of second dial gauge measurement data, and the difference of the readings of the second dial gauge at the relative positions is .

8. The method for detecting the alignment of a marine engine and an intermediate support with an elastic coupling according to claim 4, characterized in that, The crack surface deviation detection and the displacement deviation detection are simultaneously performed by means of the first dial gauge, the second dial gauge and the detection support; The detection support comprises a connecting seat plate, a transverse extension rod, a longitudinal extension rod and a dial gauge mounting rod; one end of the transverse extension rod is fixed perpendicularly on the connecting seat plate, the other end of the transverse extension rod is connected perpendicularly with one end of the longitudinal extension rod, and the other end of the longitudinal extension rod is connected perpendicularly with one end of the dial gauge mounting rod, and the dial gauge mounting rod is arranged parallel to the transverse extension rod; The first dial gauge and the second dial gauge are both installed on the dial gauge mounting rod, so that the measuring head of the first dial gauge abuts against the end face of the flange end, and the measuring head of the second dial gauge abuts against the side face of the flange end, and the readings of the first dial gauge and the second dial gauge are respectively read; the readings of several groups of the first dial gauge and the second dial gauge are measured by rotating the main machine flywheel, and the difference of the readings of the first dial gauge at the relative positions is , and the difference of the readings of the second dial gauge at the relative positions is .

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