Shaft-sticking type permanent magnet synchronous generator

Abstract

The invention discloses a journal sticking type permanent magnet synchronous generator which comprises a protection plate, a front end cover, a stator, a rotor, a rear end cover, a machine shell, a rotating shaft and a fixing assembly. The two ends of the machine shell are connected with the front end cover and the rear end cover respectively, the stator is fixed to the inner side of the machine shell, the rotor penetrates through the inner side of the stator, the rotating shaft penetrates through the inner side of the rotor and is detachably connected with the rotor, and the two ends of the rotating shaft penetrate through the front end cover and the rear end cover respectively and then extend out of the machine shell. Detachable fixing assemblies and protective plates are arranged on the mounting surfaces, facing the rotor, of the front end cover and the rear end cover; when the rotor needs to be supported, the end parts of the front end cover and the rear end cover are provided with fixing assemblies and protection plates. After the fixing assembly and the protection plate are dismounted, the rotating shaft drives the rotor to rotate, and the generator operates normally. The permanent magnet synchronous generator has the advantages of being compact in structure, convenient to disassemble and assemble, high in reliability and the like, stable supporting of the rotor is achieved, and the two problems of transportation, installation and fault emergency shaft disengaging of the permanent magnet synchronous generator without an independent shaft system and a bearing are solved.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology, and more specifically to a shaft-mounted permanent magnet synchronous generator suitable for use in marine power systems without an independent shaft system. Background Technology

[0002] In a ship's power system, the main power generation system mainly consists of a shaft-mounted permanent magnet synchronous generator, a frequency converter, and a transformer. The shaft-mounted permanent magnet synchronous generator is installed on the intermediate shaft between the propulsion diesel engine and the propeller. The intermediate shaft is connected to the diesel engine main shaft and the propeller drive shaft through couplings.

[0003] The shaft-mounted permanent magnet synchronous generator mainly consists of a stator, rotor, end covers, and protective plates. The rotor is shaftless, directly mounted on the intermediate shaft between the diesel engine and the propeller, without an independent shaft system or bearings. This design presents two core challenges: (1) Transportation and installation risks: The static magnetic attraction between the rotor and stator can reach more than 100kN, and the probability of collision increases by 60% under the condition of tilting at 15°; while the traditional whole hoisting requires ≥72 hours of dock time, accounting for 35% of the total installation time. In addition, the internal space of the cabin is small, and the intermediate shaft needs to be assembled with the motor stator and rotor as a whole before being hoisted into the cabin for installation.

[0004] (2) Emergency response requirements: When the stator and rotor jam, the rotor needs to be quickly detached and fixed to avoid shaft failure; however, the International Classification Society (ICS) requires the propulsion system to have the ability to operate continuously for 72 hours after a failure, which is difficult to meet with traditional solutions.

[0005] For ship main engine equipment, transportation and installation basically only happen once in the entire life cycle, and the probability of emergency response to motor failure is also relatively small. Therefore, how to solve the above problems economically and effectively has become one of the difficult issues that need to be considered. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a shaft-mounted permanent magnet synchronous generator that is compact in structure, easy to assemble and disassemble, and can quickly achieve rotor support and fixation, in order to overcome the shortcomings of the prior art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A shaft-mounted permanent magnet synchronous generator includes: a protective plate, a front cover, a stator, a rotor, a rear cover, a housing, a rotating shaft, and a fixing assembly. The housing is connected to the front and rear covers at both ends, respectively. The stator is fixed inside the housing, the rotor passes through the inside of the stator, and the rotating shaft passes through the inside of the rotor and is detachably connected to it. The rotating shaft extends through the front and rear covers and outwards from the housing. Detachable fixing assemblies and protective plates are provided on the mounting surfaces of the front and rear covers facing the rotor. When the rotor requires support, fixing assemblies and protective plates are installed at the ends of the front and rear covers. When the fixing assemblies and protective plates are removed, the rotating shaft drives the rotor to rotate, and the generator operates normally.

[0008] As a further improvement of the present invention, the fixing component includes a main fixing block and an auxiliary fixing block, and the main fixing block and the auxiliary fixing block are alternately arranged along the circumferential direction on both the front end cover and the rear end cover; when the rotor needs support, the main fixing block and the auxiliary fixing block overlap with the inner ring surface of the rotor.

[0009] As a further improvement of the present invention, a first mounting hole and a second mounting hole are provided radially on the mounting surfaces of the front end cover and the rear end cover. The first mounting hole is used to install the main fixing block, and the second mounting hole is used to install the auxiliary fixing block.

[0010] As a further improvement of the present invention, the main fixing block and the auxiliary fixing block are arc-shaped structures, and the arc length of the auxiliary fixing block is smaller than the arc length of the main fixing block. Both the main fixing block and the auxiliary fixing block are provided with a third mounting hole in the radial direction. Fasteners are screwed into the first mounting hole and the third mounting hole to realize the installation and fixation of the main fixing block. Fasteners are screwed into the second mounting hole and the third mounting hole to realize the installation and fixation of the auxiliary fixing block.

[0011] As a further improvement of the present invention, the mounting surface of the front end cover is provided with a first threaded hole along the axial direction, and the mounting surface of the rear end cover is provided with a through hole along the axial direction; a pusher is inserted into the through hole to push the rotor to contact the front end cover, and a fastener is screwed into the first threaded hole to realize the connection between the front end cover and the rotor.

[0012] As a further improvement of the present invention, the rear end face of the rotor is provided with a rear mating surface and a countersunk hole. The rear mating surface overlaps with the main fixing block and the auxiliary fixing block on the rear end cover, and the countersunk hole matches the through hole. The front end face of the rotor is provided with a front mating surface. The front mating surface overlaps with the main fixing block and the auxiliary fixing block on the front end cover. The front end face is provided with a second threaded hole along the axial direction. Bolts are screwed into the first threaded hole and the second threaded hole to realize the connection and fixation between the rotor and the front end cover.

[0013] As a further improvement of the present invention, the front end cover is provided with a fitting surface that matches the front end face.

[0014] As a further improvement of the present invention, both the main fixing block and the auxiliary fixing block are provided with a supporting surface, which is used to support the rotor.

[0015] As a further improvement of the present invention, the rotating shaft and the rotor are detachably connected by flanges and bolts. As a further improvement of the present invention, the protective plate is made of low alloy high strength structural steel and is fixed to the front end cover and the rear end cover by fastening bolts.

[0016] Compared with the prior art, the advantages of the present invention are as follows: The present invention relates to a shaft-mounted permanent magnet synchronous generator, which features detachable fixing components and protective plates on the mounting surfaces of both the front and rear end covers facing the rotor. The fixing components provide quick and stable support for the rotor, while the protective plates protect the entire generator and improve the reliability of the end covers' support for the rotor. When the fixing components and protective plates are removed, the rotating shaft drives the rotor to rotate, and the generator can operate normally. This invention solves two major problems in the transportation and installation of permanent magnet synchronous generators without independent shaft systems and bearings, as well as the challenges of shaft detachment in emergency situations. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structural principle of the shaft-mounted permanent magnet synchronous generator in a specific embodiment of the present invention; wherein, Figure (a) is a half-sectional view and Figure (b) is a side view; Figure 2 This is a schematic diagram of the structural principle of the front cover in a specific embodiment of the present invention; wherein, Figure (a) is a half-sectional view and Figure (b) is a front view; Figure 3 This is a schematic diagram of the structural principle of the rear end cover in a specific embodiment of the present invention; wherein, Figure (a) is a half-sectional view and Figure (b) is a front view; Figure 4 This is a schematic diagram of the structural principle of the main fixing block in a specific embodiment of the present invention; wherein, Figure (a) is the front view and Figure (b) is the side view; Figure 5 This is a schematic diagram of the structural principle of the auxiliary fixing block in a specific embodiment of the present invention; wherein, Figure (a) is the front view and Figure (b) is the side view; Figure 6 This is a schematic diagram of the rotor structure in a specific embodiment of the present invention; wherein, Figure (a) is a left view, Figure (b) is a half-sectional view, and Figure (c) is a right view; Figure 7 This is a schematic diagram illustrating the structural principle of detaching the generator shaft and fixing the rotor in a specific embodiment of the present invention; Legend: 1. Protective plate; 2. Front end cover; 3. Stator; 4. Rotor; 5. Rear end cover; 6. Main fixing block; 7. First bolt; 8. Auxiliary fixing block; 9. Housing; 10. First mounting hole; 11. Second mounting hole; 12. Mating surface; 13. First threaded hole; 14. Mounting surface; 20. Through hole; 30. Third mounting hole; 31. Lifting surface; 40. Second threaded hole; 41. Front mating surface; 42. Front end face; 43. Rear mating surface; 44. Countersunk hole; 45. Rear end face; 50. Second bolt; 51. Third bolt; 52. Rotating shaft. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0021] Example like Figure 1As shown, the present invention comprises a shaft-mounted permanent magnet synchronous generator including: a protective plate 1, a front cover 2, a stator 3, a rotor 4, a rear cover 5, a housing 9, a rotating shaft 52, and a fixing assembly. The two ends of the housing 9 are connected to the front cover 2 and the rear cover 5 respectively by screws. The stator 3 is fixed inside the housing 9, the rotor 4 passes through the inside of the stator 3, and the rotating shaft 52 passes through the inside of the rotor 4. The rotating shaft 52 and the rotor 4 are detachably connected by flanges and bolts, and both ends of the rotating shaft 52 extend to the outside of the housing 9 after passing through the front cover 2 and the rear cover 5 respectively. By setting a tapered guide structure on the rotor flange, the required alignment accuracy of the rotating shaft 52 is reduced from ±0.1mm to ±0.5mm, thus reducing the assembly accuracy requirements between the rotor 4 and the rotating shaft 52. The front cover 2 and the rear cover 5 are each provided with a detachable fixing assembly and a protective plate 1 on their mounting surfaces 14 facing the rotor 4. When the rotor 4 requires support, the fixing assembly and the protective plate 1 are installed at the ends of the front cover 2 and the rear cover 5. After the fixing components and protective plate 1 are removed, the rotating shaft 52 drives the rotor 4 to rotate, and the generator operates normally.

[0022] In this embodiment, the protective plate 1, the front cover 2 and the rear cover 5 are all welded from low alloy high strength structural steel to improve the overall structural strength of the motor. The mounting holes on the protective plate 1, the front cover 2 and the rear cover 5 are processed later. The protective plate 1 is fixed to the front cover 2 and the rear cover 5 by fastening bolts. like Figure 1 As shown, the fixing assembly includes a main fixing block 6 and an auxiliary fixing block 8. The main fixing block 6 and the auxiliary fixing block 8 are alternately arranged at 90° intervals along the circumference on both the front end cover 2 and the rear end cover 5. The main fixing block 6 and the auxiliary fixing block 8 together form a complete circle, and tooling is used to ensure that the roundness of the fixing block assembly is ≤IT7 grade, reducing the accuracy requirements for on-site installation. When the rotor 4 requires support, the main fixing block 6 and the auxiliary fixing block 8 overlap with the inner ring surface of the rotor 4.

[0023] In this embodiment, the main fixing block 6 and the auxiliary fixing block 8 form a 90° equally spaced support. The main fixing block 6 bears 70% of the load, and the auxiliary block 8 bears 30% of the load, ensuring that operation can continue even in the event of a single point of failure. This, combined with the bidirectional bolts (tensioning + lifting), achieves axial bidirectional locking of the rotor 4. Both the tensioning and lifting bolts are equipped with adjusting nuts of the same thread specification as the bolts, used to adjust the thread length of the bolts. Besides locking the rotor 4, these nuts can also be used to fasten the protective plate 1.

[0024] like Figure 2 and Figure 3 As shown, the mounting surfaces 14 of the front end cover 2 and the rear end cover 5 are provided with a plurality of first mounting holes 10 and a plurality of second mounting holes 11 in the radial direction. The first mounting holes 10 are used to install the main fixing block 6, and the second mounting holes 11 are used to install the auxiliary fixing block 8.

[0025] like Figure 4 and Figure 5 As shown, the main fixing block 6 and the auxiliary fixing block 8 have an arc-shaped structure, and the arc length of the auxiliary fixing block 8 is smaller than that of the main fixing block 6. Both the main fixing block 6 and the auxiliary fixing block 8 are provided with a third mounting hole 30 in the radial direction. A first bolt 7 is screwed into the first mounting hole 10 and the third mounting hole 30 to fix the main fixing block 6; a first bolt 7 is screwed into the second mounting hole 11 and the third mounting hole 30 to fix the auxiliary fixing block 8. Furthermore, the main fixing block 6 and the auxiliary fixing block 8 are made of low-alloy high-strength structural steel, resulting in a simple structure and low cost. Both the main fixing block 6 and the auxiliary fixing block 8 are provided with a support surface 31, which supports the rotor 4. Moreover, the end of the support surface 31 facing the rotor 4 has a ramp to facilitate smooth movement of the rotor 4.

[0026] In other embodiments, the auxiliary fixing block 8 can be removed and the main fixing block 6 can be lengthened to serve as both main and auxiliary support; or the main fixing block 6 can be shortened or replaced with multiple auxiliary fixing blocks 8 to serve as the main support.

[0027] like Figure 2 and Figure 3 As shown, the mounting surface 14 of the front cover 2 is provided with a first threaded hole 13 along the axial direction, and the mounting surface 14 of the rear cover 5 is provided with a through hole 20 along the axial direction. A pusher is inserted into the through hole 20 to push the rotor 4 into contact with the front cover 2, and a fastener is screwed into the first threaded hole 13 to connect the front cover 2 and the rotor 4.

[0028] like Figure 6 As shown, the rear end face 45 of the rotor 4 has a rear mating surface 43 and a countersunk hole 44. The rear mating surface 43 overlaps with the main fixing block 6 and the auxiliary fixing block 8 on the rear end cover 5, and the countersunk hole 44 matches the through hole 20. A third bolt 51 is inserted into the through hole 20 and the countersunk hole 44 to push the rotor 4 into contact with the front end cover 2. A fault-free shaft response of less than 30 minutes can be achieved through the preset lifting countersunk hole 44. The front end face 42 of the rotor 4 has a front mating surface 41, which overlaps with the main fixing block 6 and the auxiliary fixing block 8 on the front end cover 2. A second threaded hole 40 is provided axially on the front end face 42. A second bolt 50 is screwed into the first threaded hole 13 and the second threaded hole 40 to connect and fix the rotor 4 to the front end cover 2. The bolts for tensioning and lifting, as well as the equipped adjusting nuts, are all standard fasteners.

[0029] Furthermore, the front cover 2 is provided with a fitting surface 12 that matches the front face 42 to improve the connection stability between the rotor 4 and the front cover 2.

[0030] The generator assembly process in this embodiment is as follows: First, the stator 3 is fixed on a solid foundation. Then, the rotor 4 is inserted into the stator 3 using an assembly machine, aligning the center faces of the rotor core and the stator core. Next, the front end cover 2 and the rear end cover 5, equipped with the main fixing block 6 and the auxiliary fixing block 8, are installed on the housing 9, close to the stator 4. Finally, bolts are simultaneously tightened on the outer sides of both end covers to connect them to the housing 9. Bolts are also screwed into the inner sides of the end covers, and adjusting nuts with the same thread specification as the bolts are provided to adjust the thread length of the bolts, which reduces the number of fastening bolts on the protective plate 1 by half. Among them, the second bolt 50 on the inner side of the front end cover 2 acts as a tensioning element, and the third bolt 51 on the inner side of the rear end cover 5 acts as a lifting element, pulling and pushing the rotor 4 towards the front end cover 2, so that the front end face 42 of the rotor 4 is in contact with the mating surface 12 of the front end cover 2. In this way, the rotor 4 is completely fixed, forming a whole on the stator and the two end covers, i.e., the generator body. The generator was transported to the assembly site with the ship, and the rotor flange was bolted to the rotor shaft flange to assemble them into a single unit. This assembly was then hoisted into the ship's hold for subsequent installation. The entire hoisting process was completed in one go, reducing dock time by 58%.

[0031] After aligning the shaft system between the diesel engine, rotating shaft, and propeller, loosen the second bolt 50 on the front cover 2 and the third bolt 51 on the rear cover 3. Then adjust the axial position of the stator 4 so that the rotor core and stator core center faces are aligned. At this point, loosen the fastening bolts of the main fixing block 6 and auxiliary fixing block 8 so that the fastening bolts can slide through the third mounting holes 30 provided on the main fixing block 6 and auxiliary fixing block 8, separating the lifting surfaces 31 on the main fixing block 6 and auxiliary fixing block 8 from the rotor 4. Then tighten the fastening bolts so that the main fixing block 6 and auxiliary fixing block 8 remain on the motor body for easy reuse and to prevent loss. Similarly, adjust the radial position of the stator so that the air gap value in the circumferential direction between the stator 3 and rotor 4 meets the specified requirements. Finally, install the protective plate 1. Some fastening bolts can be replaced with bolts with adjusting nuts for fixing the rotor, which have a tightening and lifting function. At this point, the motor debugging is complete, and it can enter normal operation.

[0032] When a generator malfunctions during ship operation, such as a rotor or stator jamming, first stop the diesel engine, remove the protective plates and other components from the generator, and then proceed in the reverse order of separating the mounting block from the rotor, as described above. Figure 7As shown, the main fixing block 6 and auxiliary fixing block 8 are fixed to the end covers at both ends to support the rotor 4. Then, the generator rotor 4 is detached from the rotating shaft 52, and the rotor 4 is simultaneously pulled and pushed onto the front cover 2 with bolts and fixed. Finally, the protective plate 1 and other components are installed, and the ship can continue to sail. The troubleshooting time for ramming faults is reduced from 8 hours to 1.5 hours, the maintenance cost of the generator over its entire life cycle is reduced by 30-45%, and the collision accident rate is reduced by 92% (DNV-GL certification data). It solves the two major problems of transporting and installing permanent magnet synchronous generators without independent shafts and bearings, and emergency shaft detachment in case of failure.

[0033] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A type of permanent magnet synchronous generator with a bearing-mounted shaft, characterized in that, include: The enclosure comprises a protective plate (1), a front cover (2), a stator (3), a rotor (4), a rear cover (5), a housing (9), a rotating shaft (52), and a fixing assembly; the two ends of the housing (9) are connected to the front cover (2) and the rear cover (5) respectively; the stator (3) is fixed inside the housing (9); the rotor (4) passes through the inside of the stator (3); the rotating shaft (52) passes through the inside of the rotor (4) and is detachably connected to the rotor (4); and the two ends of the rotating shaft (52) are respectively... The front cover (2) and rear cover (5) extend to the outside of the housing (9); the front cover (2) and rear cover (5) are provided with detachable fixing components and protective plates (1) on the mounting surface (14) facing the rotor (4); when the rotor (4) needs support, the fixing components and protective plates (1) are installed at the ends of the front cover (2) and rear cover (5); when the fixing components and protective plates (1) are removed, the rotating shaft (52) drives the rotor (4) to rotate, and the generator operates normally.

2. The shaft-mounted permanent magnet synchronous generator according to claim 1, characterized in that, The fixing components include a main fixing block (6) and an auxiliary fixing block (8). The main fixing block (6) and the auxiliary fixing block (8) are alternately arranged along the circumferential direction on the front end cover (2) and the rear end cover (5). When the rotor (4) needs support, the main fixing block (6) and the auxiliary fixing block (8) overlap with the inner ring surface of the rotor (4).

3. The shaft-mounted permanent magnet synchronous generator according to claim 2, characterized in that, The front end cover (2) and the rear end cover (5) are provided with a first mounting hole (10) and a second mounting hole (11) in the radial direction on the mounting surface (14). The first mounting hole (10) is used to install the main fixing block (6), and the second mounting hole (11) is used to install the auxiliary fixing block (8).

4. The shaft-mounted permanent magnet synchronous generator according to claim 3, characterized in that, The main fixing block (6) and the auxiliary fixing block (8) are arc-shaped structures, and the arc length of the auxiliary fixing block (8) is smaller than that of the main fixing block (6). The main fixing block (6) and the auxiliary fixing block (8) are both provided with a third mounting hole (30) in the radial direction. Fasteners are screwed into the first mounting hole (10) and the third mounting hole (30) to install and fix the main fixing block (6). Fasteners are screwed into the second mounting hole (11) and the third mounting hole (30) to install and fix the auxiliary fixing block (8).

5. The shaft-mounted permanent magnet synchronous generator according to claim 3, characterized in that, The front cover (2) has a first threaded hole (13) on its mounting surface (14) along the axial direction, and the rear cover (5) has a through hole (20) on its mounting surface (14) along the axial direction. A pusher is inserted into the through hole (20) to push the rotor (4) to contact the front cover (2), and a fastener is screwed into the first threaded hole (13) to connect the front cover (2) and the rotor (4).

6. The shaft-mounted permanent magnet synchronous generator according to claim 5, characterized in that, The rear end face (45) of the rotor (4) is provided with a rear mating surface (43) and a countersunk hole (44). The rear mating surface (43) overlaps with the main fixing block (6) and the auxiliary fixing block (8) on the rear end cover (5). The countersunk hole (44) matches the through hole (20). The front end face (42) of the rotor (4) is provided with a front mating surface (41). The front mating surface (41) overlaps with the main fixing block (6) and the auxiliary fixing block (8) on the front end cover (2). The front end face (42) is provided with a second threaded hole (40) along the axial direction. Bolts are screwed into the first threaded hole (13) and the second threaded hole (40) to realize the connection and fixation between the rotor (4) and the front end cover (2).

7. The shaft-mounted permanent magnet synchronous generator according to claim 6, characterized in that, The front cover (2) is provided with a fitting surface (12) that matches the front surface (42).

8. The shaft-mounted permanent magnet synchronous generator according to any one of claims 2 to 7, characterized in that, Both the main fixing block (6) and the auxiliary fixing block (8) are provided with a support surface (31), which is used to support the rotor (4).

9. The shaft-mounted permanent magnet synchronous generator according to any one of claims 1 to 7, characterized in that, The rotating shaft (52) and the rotor (4) are detachably connected by flanges and bolts.

10. The shaft-mounted permanent magnet synchronous generator according to any one of claims 1 to 7, characterized in that, The protective plate (1) is made of low alloy high strength structural steel and is fixed to the front cover (2) and the rear cover (5) by fastening bolts.

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