A method for splicing a marine crankshaft

Abstract

The invention discloses a method for splicing a marine crankshaft, which comprises the following steps: installing an adjusting support frame under each journal of two segmented crankshafts to be spliced; measuring the coaxiality of each segmented crankshaft when rotating it and finishing a pair of flange holes; adjusting the coaxiality accordingly by adjusting the support frame; and alternately connecting all the flange holes in the order of first installing expansion bolts and then rotating connecting bolts, so as to realize the splicing of the marine crankshaft and accurately ensure the coaxiality thereof.

Description

Technical Field

[0001] The invention belongs to the crankshaft processing technology, and in particular relates to a marine crankshaft splicing method. Background Art

[0002] In the manufacturing process of large-scale marine butt crankshafts in the prior art, two segmented crankshafts need to be spliced ​​together through the connecting flanges at their respective butt ends. During the splicing process, how to ensure the coaxiality between the two segmented crankshafts is a current difficulty and an important prerequisite for ensuring assembly accuracy and smooth engine operation. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a marine crankshaft splicing method, which can effectively ensure the coaxiality of the crankshaft during the entire splicing process.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A method for splicing a marine crankshaft comprises the following steps:

[0006] A. The connecting flanges and flange holes of the two segmented crankshafts are arranged opposite to each other, and an adjustment support frame is arranged at the bottom of each journal of the two segmented crankshafts, the adjustment support frame includes a support frame body with a V-shaped groove on the top, and an adjustment mechanism is arranged on the inclined surfaces on both sides of the V-shaped groove, each adjustment mechanism includes a housing, a sliding column, and an adjustment screw. A sliding cavity is arranged in the housing, and the rear end of the sliding column is arranged in the sliding cavity and axially opened with a guide hole, and a movable nut is fixed at the rear end of the guide hole, and the front end of the sliding column is radially in contact with the lower side of the journal, and the front end of the adjusting screw is arranged in the housing through a bearing and penetrates into the sliding column guide hole and cooperates with the movable nut thread, and the rear end has a rotating pull end, and the housing is also provided with a locking bolt that can be radially tightened with the sliding column;

[0007] B. A coaxiality detection device is provided on one side of each journal, and the telescopic probe of each coaxiality detection device is in horizontal radial contact with the journal;

[0008] C. Rotate the two-section crankshafts to rotate any pair of flange holes to the finishing position. At the same time, according to the detection result of the coaxiality detection device, rotate the adjusting screw of the corresponding side adjustment mechanism to drive the sliding column to adjust the coaxiality of the journal to ensure the coaxiality of the two-section crankshafts;

[0009] D. Perform finishing boring on the pair of flange holes using a boring tool;

[0010] E. Install expansion bolts into the pair of flange holes and tighten them. The expansion bolts include a shaft core, an adjustment block, an expansion sleeve, and an adjustment nut. The shaft core has a step at one end and an external thread at the other end. The adjustment block has an axial hole and is in a conical shape with a smaller inner diameter and a larger outer diameter, and is sleeved on the shaft core through the axial hole. The inner hole of the expansion sleeve matches the adjustment block, one end is fixed to the step of the shaft core, and the other end is sleeved on the adjustment block. The expansion sleeve is also axially provided with a plurality of expansion grooves. The adjustment nut is arranged on the shaft core through threaded matching and abuts against the expansion sleeve to adjust the expansion sleeve to tighten the flange hole.

[0011] F. Rotate the two-section crankshafts to bring the next pair of flange holes to the finishing position and simultaneously check and adjust the coaxiality to ensure the coaxiality of the two-section crankshafts. Then, perform finishing boring on the next pair of flange holes and connect the pair of flange holes and the corresponding holes of the sprockets on the two connecting flanges together through connecting bolts;

[0012] G. Repeat steps CF to inspect and adjust the coaxiality of the remaining flange holes, perform finishing boring, and alternately install expansion bolts and connecting bolts;

[0013] H. Tighten all connecting bolts.

[0014] A hydraulic jack supporting the bottom of the journal is longitudinally arranged in the middle of the V-shaped groove.

[0015] The contact ends of the hydraulic jack, the sliding column and the shaft neck are all provided with cushion blocks.

[0016] The bottom of the cushion block is matched and connected with the hydraulic jack and the sliding column through a dovetail groove, and the top is compounded with a Babbitt alloy layer.

[0017] The contact area between the expansion sleeve and the adjustment block is at least 80%.

[0018] The coaxiality detection device adopts a micrometer.

[0019] The marine crankshaft splicing method of the present invention has the following advantages:

[0020] 1. Before boring each pair of flange holes, the journal position can be adjusted accordingly according to the coaxiality measurement results by adjusting the adjustment mechanism of the support frame to ensure the coaxiality of the entire crankshaft and the coaxiality and accuracy of the flange hole finishing;

[0021] 2. By installing the expansion bolts first, it can be ensured that the coaxiality between the two segmented crankshafts will not change due to the rotation of the segmented crankshafts, and the precision of boring and finishing is also guaranteed;

[0022] 3. Alternate installation of expansion bolts and connecting bolts can ensure coaxiality during the entire splicing process;

[0023] 4. The setting of the hydraulic jack can bear part of the weight of the crankshaft, so that the adjusting mechanism can save more effort during the adjustment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] Figure 1 It is a stereoscopic diagram of two segmented crankshafts of the present invention arranged relatively to each other;

[0026] Figure 2 It is an axial view of an adjustable support frame installed at a journal of the present invention;

[0027] Figure 3 It is a three-dimensional schematic diagram of the installation of the journal and the adjustment support frame of the present invention;

[0028] Figure 4 is a cross-sectional view of the adjustment mechanism of the present invention;

[0029] Figure 5 is a cross-sectional view of a cushion block of the present invention;

[0030] Figure 6 is a cross-sectional view of an expansion bolt of the present invention;

[0031] Figure 7 It is a structural schematic diagram of the expansion sleeve of the present invention;

[0032] Figure 8 It is a structural schematic diagram of the connecting bolt of the present invention;

[0033] Fig. 9 It is a schematic diagram of the structure of the crankshaft after splicing of the present invention;

[0034] Fig.10 , Fig.11 are stereoscopic views of the expansion bolt of the present invention installed in a connecting flange from different viewing angles;

[0035] Fig.12 It is a three-dimensional schematic diagram of the sprocket of the present invention. DETAILED DESCRIPTION

[0036] A marine crankshaft splicing method of the present invention is as follows Figure 1-12 As shown, the following steps are included:

[0037] A. The connecting flanges 1 and flange holes 2 of the two-segment crankshafts are arranged opposite to each other, and an adjustment support frame 4 is arranged at the bottom of each journal 3 of the two-segment crankshafts. The adjustment support frame 4 includes a support frame body 41 with a V-shaped groove on the top, such as Figure 2-3As shown, the support frame body 41 can be directly designed as a Y shape, and a hydraulic jack 42 supporting the bottom of the journal 3 is longitudinally arranged in the middle of the V-shaped groove for adjusting the height in the Y-axis direction. An adjustment mechanism 43 is respectively arranged on the inclined surfaces on both sides of the V-shaped groove. Figure 4 As shown, each adjustment mechanism 43 includes a housing 431, a slide post 432, and an adjusting screw 433. A sliding cavity is provided in the housing 431. The rear end of the slide post 432 is provided in the sliding cavity and a guide hole is axially opened. A sliding nut 439 is fixed to the rear end of the guide hole by a fixing bolt. The front end of the slide post 432 is in radial contact with the lower side of the shaft neck 3, and the two slide posts 432 are arranged at an angle of 90°. The front end of the adjusting screw 433 is provided in the housing 431 through a bearing 438 and passes through the guide hole at the rear end of the slide post 432 and is in contact with the shaft neck 3. The sliding nut 439 is threadedly matched, and the rear end has a rotating pull end 434, which can drive the sliding column 432 to slide by a wrench, so as to adjust the left and right position of the journal 3. The housing 431 is also provided with a locking bolt 435 that can be radially tightened with the sliding column 432 to adjust the locking after it is in place; the front end opening of the housing 431 is also provided with a copper sleeve 436, and the rear end opening is provided with a fixing ring 437; In addition, each hydraulic jack 42, the contact end of the sliding column 432 and the journal 3 is provided with a pad 44, please combine Figure 5 As shown, the bottom of the pad 44 can be connected with the hydraulic jack 42 and the sliding column 432 through a dovetail groove 45, and the contact surface between the top and the journal 3 is a composite babbitt alloy layer 46;

[0038] B. A coaxiality detection device (not shown in the figure) is respectively provided on one side of each journal 3, which can usually be a micrometer or the like, and the telescopic probe of each coaxiality detection device is horizontally and radially contacted with the journal 3;

[0039] C. Rotate the two-section crankshafts to rotate any pair of flange holes 2 to the finishing position. At the same time, according to the detection result of the coaxiality detection device, the adjusting screw 433 of the corresponding side adjustment mechanism 43 is rotated to drive the sliding column 432 to adjust the coaxiality of the journal 2 to the left and right, so that the two-section crankshafts are coaxial.

[0040] D. Perform finishing boring on the pair of flange holes using a boring tool;

[0041] E. Install the expansion bolts 5 into the flange holes 2 and tighten them. Figure 6-7As shown, the expansion bolt 5 includes a shaft core 51, an adjustment block 52, an expansion sleeve 53, and an adjusting nut 54. The shaft core 51 has a step 56 at one end and an external thread at the other end. The adjustment block 52 has an axial hole and is in a conical shape with a small inner diameter and a large outer diameter, and is sleeved on the shaft core 51 through the axial hole; the inner hole of the expansion sleeve 53 matches the adjustment block 52, one end is fixed to the step of the shaft core 51, and the other end is sleeved on the adjustment block 52, and the contact surface between the expansion sleeve 53 and the adjustment block 52 should be at least 80%, a plurality of expansion grooves 55 are also axially opened on the expansion sleeve 53, and the adjusting nut 54 is arranged on the shaft core 51 through threaded cooperation and abuts against the expansion sleeve 53. When the expansion bolt 5 is installed in the flange hole, the adjusting block 52 and the expansion sleeve 53 can be relatively slid by screwing the adjusting nut 54, and the expansion sleeve 53 can be expanded by the action of the conical surface, so that the two flange holes 2 are tightened together, so that the two connecting flanges 1 are not easily displaced, and the coaxiality during the rotation process is further ensured;

[0042] F. Rotate the two-section crankshaft to make the next pair of flange holes 2 reach the finishing position, and use the same detection and adjustment method as step C to ensure the coaxiality of the two-section crankshafts, and then bore and finish the flange holes 2, and connect the pair of flange holes 2 and the corresponding holes 71 of the sprocket 7 on the two connecting flanges 1 (see Figure 10-12 ) are arranged together, and the connecting screw 6 can be adopted as Figure 8 The structure shown;

[0043] G. Repeat steps CF to inspect and adjust the coaxiality of the remaining flange holes 2, perform fine boring and alternate installation of expansion bolts 5 and connecting bolts 6, until all flange holes 2 are installed and connected. It should be noted that the connecting bolts 6 do not need to be tightened during installation;

[0044] H. Tighten all the connecting bolts 6 to complete the connection between the two connecting flanges 1 and the sprocket 7.

[0045] However, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for splicing a marine crankshaft, characterized in that: The following steps are included: A. The connecting flanges and flange holes of the two segmented crankshafts are arranged opposite to each other, and an adjustment support frame is arranged at the bottom of each journal of the two segmented crankshafts, the adjustment support frame includes a support frame body with a V-shaped groove on the top, and an adjustment mechanism is arranged on the inclined surfaces on both sides of the V-shaped groove, each adjustment mechanism includes a housing, a sliding column, and an adjustment screw. A sliding cavity is arranged in the housing, and the rear end of the sliding column is arranged in the sliding cavity and axially opened with a guide hole, and a movable nut is fixed at the rear end of the guide hole, and the front end of the sliding column is radially in contact with the lower side of the journal, and the front end of the adjusting screw is arranged in the housing through a bearing and penetrates into the sliding column guide hole and cooperates with the movable nut thread, and the rear end has a rotating pull end, and the housing is also provided with a locking bolt that can be radially tightened with the sliding column; B. A coaxiality detection device is provided on one side of each journal, and the telescopic probe of each coaxiality detection device is in horizontal radial contact with the journal; C. Rotate the two-section crankshaft to rotate any pair of flange holes to the finishing position. At the same time, according to the detection result of the coaxiality detection device, rotate the adjusting screw of the corresponding side adjustment mechanism to drive the sliding column to adjust the coaxiality of the journal; D. Perform finishing boring on the pair of flange holes using a boring tool; E. Install expansion bolts into the pair of flange holes and tighten them. The expansion bolts include a shaft core, an adjustment block, an expansion sleeve, and an adjustment nut. The shaft core has a step at one end and an external thread at the other end. The adjustment block has an axial hole and is in a conical shape with a smaller inner diameter and a larger outer diameter, and is sleeved on the shaft core through the axial hole. The inner hole of the expansion sleeve matches the adjustment block, one end is fixed to the step of the shaft core, and the other end is sleeved on the adjustment block. The expansion sleeve is also axially provided with a plurality of expansion grooves. The adjustment nut is arranged on the shaft core through threaded matching and abuts against the expansion sleeve to adjust the expansion sleeve to tighten the flange hole. F. Rotate the two-section crankshafts to bring the next pair of flange holes to the finishing position and simultaneously check and adjust the coaxiality, perform finishing boring on the next pair of flange holes, and use connecting bolts to insert the pair of flange holes into the corresponding holes of the sprockets on the two connecting flanges; G. Repeat steps CF to inspect and adjust the coaxiality of the remaining flange holes, perform finishing boring, and alternately install expansion bolts and connecting bolts; H. Tighten all connecting bolts.

2. A marine crankshaft splicing method according to claim 1, characterized in that: A hydraulic jack supporting the bottom of the journal is longitudinally arranged in the middle of the V-shaped groove.

3. A marine crankshaft splicing method according to claim 2, characterized in that: The contact ends of the hydraulic jack, the sliding column and the journal are all provided with cushion blocks.

4. A marine crankshaft splicing method according to claim 3, characterized in that: The bottom of the cushion block is matched and connected with the hydraulic jack and the sliding column through a dovetail groove, and the top is compounded with a Babbitt alloy layer.

5. A marine crankshaft splicing method according to claim 1, characterized in that: The contact area between the expansion sleeve and the adjustment block is at least 80%.

6. A marine crankshaft splicing method according to claim 1, characterized in that: The coaxiality detection device adopts a micrometer.

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